@article {4171, title = {BRIEF COMMUNICATION: Can the effects of intrauterine growth retardation on bone morphology be overcome by first calving? - A preliminary study.}, journal = {New Zealand Journal of Animal Science and Production}, volume = {84}, year = {2024}, pages = {26-29}, address = {Oamaru}, abstract = {

Intrauterine growth retardation, reduced bone density, and an increased risk of fracture were observed in a cohort of calves born to dams fed a diet of baleage and either fodder beet or kale during winter. This study aimed to examine whether the intrauterine effects of the dam{\textquoteright}s diet on bone development can be overcome by the time the calf reaches its first lactation. Heifer calves from these cohorts were grown, mated, calved, and milked under standard farm practice. At 11 weeks post-calving, heifers were slaughtered, and the humerus was collected and scanned using peripheral quantitative computed tomography (pQCT). There were no differences in pQCT measures of bone size, density, and strength between heifers whose dams were wintered on kale or fodder beet before calving (p\>0.05). Results indicate subsequent bone growth and development after birth may compensate for the intrauterine effects of late gestation dam diet.

}, author = {Gibson, M.J. and Rogers, C.W. and Back, P.J. and Kittmer, K.E. and Wehrle-Martinez, A.S. and Dalley, D.E. and Woods, R.R.} } @article {4162, title = {BRIEF COMMUNICATION: Effects of measuring methane in pregnant ewes using portable accumulation chambers on pregnancy outcomes and lamb performance to weaning}, journal = {New Zealand Journal of Animal Science and Production}, volume = {84}, year = {2024}, pages = {7-10}, address = {Oamaru}, abstract = {

The portable accumulation chamber (PAC) method provides an on-farm methane measurement over a short timeframe that is scalable to measure large numbers of animals. The aim of this study was to assess the safety of use of PAC in pregnant ewes. Methane production was measured in ewes (n=40 per group) using PAC at approximately 70 or 100 days of gestation. Control animals were either exposed to yarding and sorting only (Days 70 and 100) or exposed to yarding, sorting and restriction from feed as outlined in the standard operating procedure for PAC (Day 100 only). Ewe health was not differentially affected by PAC measurement. Confinement in PAC did not affect (P\>0.50) lamb survival, with the proportion of lambs weaned relative to number at mid-pregnancy ranging between 0.817 to 0.898. Birth and weaning weights of the lamb were similar (P\>0.28) between all groups (birth weight ranged between 4.8 to 5.1 kg, weaning weight ranged between 28.1 to 29.3 kg). Carbon dioxide levels in PAC were not elevated compared to what has previously been observed in non-pregnant ewes. Methane concentrations were calculated for the ewes around day 100 of pregnancy and the average methane production was 23.2 {\textpm} 5.8 g per day. In conclusion, PAC appears to be a safe method for measuring methane traits in ewes during the middle to later stages of pregnancy.

}, author = {Peers-Adams, J. and Bilton, T.P. and Rowe, S.J. and Juengel, J.L.} } @article {4166, title = {BRIEF COMMUNICATION: Exploration of the New Zealand Deer Rumen Microbiome}, journal = {New Zealand Journal of Animal Science and Production}, volume = {84}, year = {2024}, pages = {19-22}, abstract = {

Rumen microbial communities (RMC) have been shown to be affected by the host individual{\textquoteright}s genetics and are heritable in sheep and cattle. RMC are predictive of feed related traits such as methane emissions, a by-product of the fermentation process. The aim of this project was to determine the variability in RMC amongst deer and to estimate heritability of the deer RMC. The rumen contents of 409 red and wapiti cross deer were sampled, and microbial DNA was sequenced. The genome taxonomy database was used to determine taxonomy assignment at the genus level. Sequences were used to determine similarity of RMC amongst individuals and presence of known microbes. Similar to other ruminants, Prevotella was the most abundant genus present in the deer RMC. Dimension reduction methods were applied to three standardisation methods to examine the variation in the RMC. Heritability estimates for the first two components of the reduced dimensions of the RMC ranged from 0.078 ({\textpm} 0.058) to 0.72 ({\textpm} 0.21) across the standardisation methods. This suggests that the deer RMC is controlled by host genomics.

}, keywords = {Deer, Heritability, Microbiome, Rumen}, author = {Clarke, J.L. and Bilton, T.P. and Henry, H. and McRae, K.M. and Booker, F. and Veenvliet, B. and Bain, W. and Ward, J.A. and Thompson, B. and McEwan, J.C. and Perry, B.J. and Black, M.A. and Rowe, S.J.} } @article {4165, title = {BRIEF COMMUNICATION: Influence of the {\textquoteleft}SLICK{\textquoteright} allele of the prolactin receptor gene (PRLR) on the growth and behaviour of dairy heifers during winter.}, journal = {New Zealand Journal of Animal Science and Production}, volume = {84}, year = {2024}, pages = {15-18}, address = {Oamaru}, abstract = {

This study investigated the effects of the SLICK allele on the responses of dairy heifers in cold conditions in New Zealand. Three groups (n=9/group), control, non-SLICK and SLICK progeny of bulls heterozygous for the SLICK allele were investigated. These heifers were grazed together to identify their responses to winter conditions under adequate, followed by restricted feed allocation. The control group had an 87\% lower growth rate during the restricted period compared to the SLICK group (0.064 vs 0.484 kg/d, P = 0.035). During restricted feeding conditions, the SLICK heifers showed improved pasture harvesting efficiency, by maintaining growth rate while having a lower eating time, compared to the control heifers (277 vs 317 {\textpm} 10.9 mins/day respectively, P = 0.017). The SLICK group were also less active than the control group. These differences indicate more research is needed to understand the wider role of the prolactin axis on the physiological responses of SLICK cattle.

}, author = {Robb, L.A. and Bryan, R.H. and Beckett, B.P. and Donkersloot, E.G. and Worth, G.M. and Zhou, H. and Hickford, J.G.H.} } @article {4161, title = {BRIEF COMMUNICATION: Liveweight, body composition, carcass traits and meat quality of artificially reared milk-fed Friesian Jersey crossbred heifer and bull calves}, journal = {New Zealand Journal of Animal Science and Production}, volume = {84}, year = {2024}, pages = {1-3}, address = {Oamaru}, abstract = {

Novel approaches are required by the dairy industry to identify productive endpoints for surplus calves beyond 4-day-old bobby calves. The objective of this study was to characterise carcass weight, body composition, and meat quality attributes of ~11-week-old milk-fed dairy bull and heifer calves. Mixed-sex Friesian-Jersey crossbred dairy calves (n=73) were artificially reared. Calves were weighed at birth and slaughter. Carcass weight, heart girth, and the weight of selected organs and muscles were recorded. Meat quality parameters were evaluated including muscle pH, colour, and intramuscular fat percentage (IMF). Bulls had greater average daily gain (P=0.003), slaughter weight (P=0.007), and carcass weight (P=0.022) than heifers. IMF \% (P=0.038), redness (P=0.009), yellowness (P=0.041), and chroma (P=0.011) were greater in heifers than bulls, while pH, lightness, and hue angle were similar (P\>0.05). This study provides new information to inform the potential utilisation of milk-fed calves for novel meat products.

}, author = {McCoard, S.A. and Pavan, E. and Taukiri, K. and Zhang, R. and Realini, C.E.} } @article {4160, title = {BRIEF COMMUNICATION: Rate of Genetic Gain for Methane Emissions in a Maternal Production Flock}, journal = {New Zealand Journal of Animal Science and Production}, volume = {84}, year = {2024}, pages = {4-6}, address = {Oamaru}, abstract = {

Global warming attributed to methane emissions from livestock presents a significant global challenge to the agricultural sector. Although opportunities exist in intensive systems for feed additives, the only proven tool for permanent mitigation at a national level, across sectors, is animal breeding. It has been reported that enteric methane emission is a heritable trait, and that breeding is an effective mitigation strategy. The impacts of incorporating methane into existing breeding schemes are less understood. Selection for reduced methane emissions (measured by portable accumulation chamber; PAC) along with increased productivity (NZMW+FEC+DAGS+MEAT index) was implemented in 2017 in the Woodlands 2638 flock. The economic weighting for methane was NZ$100/tonne GWP100 CO2e. The economic weights for existing traits were unchanged. Breeding value trends per year for flock 2638 and the Dual Purpose industry average for born 2018 to 2023 progeny were estimated as -0.95 vs -0.01\%, -0.2 vs 0.06\%, 0.18 vs 0.12kg, 133 vs 89 cents, and 185 vs 110 cents for PACCH4gBV\%, PACCO2gBV\%, LW8gBV, NZMW and NZMW+FEC+DAGS+MEAT indexes respectively. Gene flow calculations suggest that methane emissions could be reduced by 27\% by 2050 while increasing per head productivity by $51.80. Continuation with current industry progress would achieve a 2.8\% reduction in methane emissions and $30.80 increase in per head productivity. In summary, methane emissions can be reduced while also increasing productivity faster than current industry progress.

}, keywords = {breeding, methane, PAC, sheep}, author = {Booker, F. and McEwan, J.C. and Rowe, S.J.} } @article {4163, title = {BRIEF COMMUNICATION: The behaviour and impact of sheep accessing a natural waterway in summer}, journal = {New Zealand Journal of Animal Science and Production}, volume = {84}, year = {2024}, pages = {11-14}, address = {Oamaru}, abstract = {

New Zealand there are regulations to fence waterways \>1m in width to restrict the access of farmed cattle, deer and pigs, however, there are no such requirements for sheep. The behaviour of sheep around natural waterways and their impact on water quality is unknown. Our previous study showed that in winter there was little interaction of pregnant ewes with the waterway (Bunyaga et al. 2023), however, warmer temperatures in spring may result in different behaviour.\ 
In November 2019, observations of the interaction of lactating mixed-age Romney ewes (n=40) with a natural waterway 233 m in length, ~1 m wide and 30 cm deep at Massey University{\textquoteright}s hill country farm, Tuapaka. Ewes were continuously stocked on a 1.7 ha perennial ryegrass paddock with a pasture mass above 1000 kgDM/ha. Ewe behaviour and movements were monitored continuously for two weeks using GPS devices, Bluetooth proximity and motion-activated trail cameras. Ewes were restricted from accessing the water trough in the first week of observation and provided access to the trough in the second week. Weather data was recorded by a weather station located 800 m from the study site. Samples of stream water were collected across two days at the end of each week of the study for water quality testing. \ The stream zone represented 9\% of the paddock area, however, less than 0.7\% of all ewe GPS location fixes throughout the study were recorded in this area. During the observation period, ewes spent more time within 3m (10.6 {\textpm} 0.6 min/ewe/day; p\<0.05; riparian zone) of the stream during the period the access to the trough was restricted than when allowed access. Ewe behaviour within 3m of the stream showed that ewes sniffed the water but did not drink on 28 occasions and walked in the water on eight occasions. During the entire observation period ewes spent less (P\<0.05) time within 3m of the stream between 8pm and 5am than any other period of the day. This data suggests that sheep spent little of their time near the stream but were observed at times to drink from and walk in the stream.

}, author = {Bunyaga, A . and Barnes, C. and Draganova, I. and Kenyon, P. and Burkitt, L. and Corner-Thomas, R.} } @article {4167, title = {BRIEF COMMUNICATIONS: Effect of feeding a hyper-diverse pasture mix on pre-weaning ewe and lamb performance}, journal = {New Zealand Journal of Animal Science and Production}, volume = {84}, year = {2024}, pages = {23-25}, address = {Oamaru}, abstract = {

This study investigates the effect of feeding a hyper-diverse pasture mix on pre-weaning ewe and lamb performance. Ewes were allocated to either standard pasture (ryegrass/red and white clover) or a hyper-diverse pasture mix (containing 21 species) at set-stocking and grazed that pasture type until weaning. Ewe and lamb live weights, lamb survival and pasture masses were monitored throughout the period. There was no difference (P\>0.05) in lamb live weight at birth, docking or lamb survival between those that grazed the standard pasture compared to the hyper-diverse pasture. At weaning, there was no difference (P\>0.05) in the live weight of ewes which grazed the two pasture types, however, lambs which grazed the hyper-diverse pasture were heavier than lambs which grazed the standard pasture. There was no difference (P\>0.05) in average pasture mass of the two pasture types at a given timepoint (set-stocking, docking, post-docking, weaning). However, at docking the average pasture mass in the hyper-diverse pasture dropped below 1200 kg DM/ha which likely resulted in restricted feed intake of ewes and lambs. This study suggests indicates more research is required to determine the combined effect of pasture masses, botanical composition and pasture quality in hyper-diverse pasture mixes on ewe and lamb performance during the lactation period.

}, author = {Gronqvist, G.V. and Cranston, L.M. and Roca Fraga, F.J. and Sneddon, N.W. and Kenyon, P.R.} } @article {4170, title = {Special Issue of New Zealand Journal of Agricultural Research to Come}, journal = {New Zealand Journal of Agricultural Research}, volume = {84}, year = {2024}, address = {Oamaru}, abstract = {

A special edition of\ the New Zealand Journal of Agricultural Research (NZJAR) will be compiled based\ from the 84th\ conference of the New Zealand Society of Animal Production (NZSAP) held in Oamaru in November 2024.\ 

The papers in this special edition will bring together multiple disciplines that were presented at the conference.\ 

}, author = {NZJAR} } @article {3672, title = {BRIEF COMMUNICATION: An evaluation of the AGTECH360 Livestock Tracker for the automated recording of on-farm grazing events.}, journal = {New Zealand Journal of Animal Science and Production}, volume = {83}, year = {2023}, month = {01/2023}, pages = {1-4}, address = {Rotorua}, abstract = {Many New Zealand farmers either do not record paddock grazing events or do not retain grazing data after making decisions about cow feeding and pasture management. This study, conducted at the Northland Agriculture Research Farm (NARF), aimed to determine whether GPS-enabled devices suitable for use on cattle could be used to automate the recording of grazing events on-farm. Accordingly, 12-13 cows within each of the three herds (herd size range 59- 85 cows) were fitted with an AGTECH360 Livestock Tracker from 1 December 2021 to 31 March 2022. The GPS location data were then compared with manual grazing records. The grazed paddock was correctly identified on 80- 92\% of occasions, depending on the herd. These results indicate that it is feasible to automate the recording of onfarm grazing events by fitting a proportion of the herd with GPS-enabled devices. Keywords: dairy farm systems; grazing records; global positioning systems (GPS); Internet of Things (IoT); low-power wide-area network (LPWAN); LoRa}, issn = {1176-5283}, author = {WA Hofmann and JP Edwards and MB Neal} } @article {3672, title = {BRIEF COMMUNICATION: Approaches to breeding heat tolerant dairy cattle }, journal = {New Zealand Journal of Animal Science and Production}, volume = {83}, year = {2023}, month = {01/2023}, pages = {8-10}, address = {Rotorua}, abstract = {Climate change will become increasingly problematic for grazing cattle, with heat stress impacting both animal welfare and productivity. Genetic strategies are available to mitigate heat stress, some of which such as crossbreeding, have already been tested in tropical climates. Heat tolerance is a heritable trait in dairy cattle and genetic progress can be achieved using genomic selection, an approach adopted in Australia. Another strategy is to introgress the SLICK genetic variant from Senepol beef cattle into dairy cattle. This enables a 0.5 to 1.0 {\textdegree}C advantage in rectal and ruminal temperature, relative to control cows, when under a mild heat load. This variant has already been introduced into breeds of beef cattle by gene editing, an approach which promises to greatly accelerate gene introgression for single gene traits and lessen the potential impact of introgression on inbreeding in a population. Keywords: heat tolerance, dairy cattle, SLICK, breeding}, issn = {1176-5283}, author = {EG Donkersloot and GM Worth and LR McNaughton and A Yeates and SR Davis and RJ Spelman} } @article {3672, title = {BRIEF COMMUNICATION: Considerations to cost-effectively automate batch milking in pastoral dairy systems without distributing milkings over 24 h.}, journal = {New Zealand Journal of Animal Science and Production}, volume = {83}, year = {2023}, month = {01/2023}, pages = {11-13}, address = {Rotorua}, abstract = {Current technological limitations mean that to cost-effectively automate batch milking, without distributing milkings over 24 h, a rethink of the farm and milking system is required. A model and a range of non-optimised scenarios were developed for a 300-cow herd to illustrate the trade-offs between the number of automated milking points required (cost) and the duration of {\textquoteleft}on-call{\textquoteright} time for the person overseeing milking. Compared to the base scenario of 30 milking points (equivalent to conventional milking), by milking the herd in three groups of 100 and adjusting the twice-a-day milking interval from 9-15 h to 6-18 h, the number required could be reduced to 12, with a similar {\textquoteleft}on-call{\textquoteright} time. Further adjustments could reduce the number of milking points to 7 by milking once-a-day, although five groups of 60 cows would be required to keep cow waiting time below 2 h. These results demonstrate the potential flexibility of current automated milking technology for batch milking. Keywords: dairy farm systems; automated milking; batch-milking}, issn = {1176-5283}, author = {JP Edwards and BT Dela Rue and JG Jago} } @article {3672, title = {BRIEF COMMUNICATION: Effects of the SLICK gene on heat tolerance in grazing dairy cattle}, journal = {New Zealand Journal of Animal Science and Production}, volume = {83}, year = {2023}, month = {01/2023}, pages = {5-7}, address = {Rotorua}, abstract = {

The heat tolerance of Senepol beef cattle (Bos taurus) has been causally linked to a mutation in the prolactin receptor (PRLR) on BTA20. This variant of PRLR has become known as the SLICK gene because it is also associated with a short-hair coat. We have investigated the heat tolerance of New Zealand dairy cattle bred to carry the SLICK gene, using measurement of vaginal temperature. Hair length differed (P\<0.001) between SLICKs and controls at the neck (4.3 {\textpm} 0.5 mm vs 13.8 {\textpm} 1.2 mm, respectively), shoulder (6.5 {\textpm} 0.7 mm vs 14.9 {\textpm} 1.5 mm, respectively) and pin bone (6.9 {\textpm} 0.6 mm vs 15,2 {\textpm}1.4 mm, respectively). Vaginal temperatures of SLICK animals were 0.5 - 1{\textdegree}C lower than controls at peak ambient temperature (28.4{\textdegree}C; 16.00h). SLICK dairy cattle show a markedly improved ability for temperature homeostasis under mild heat load, relative to control cattle. Keywords: heat tolerance; dairy cattle; SLICK; genetics

}, issn = {1176-5283}, author = {GM Worth and EG Donkersloot and RJ Spelman and SR Davis} } @article {3672, title = {BRIEF COMMUNICATION: Maternally supplemented L-glutamine increases growth rates of twin lambs from birth}, journal = {New Zealand Journal of Animal Science and Production}, volume = {83}, year = {2023}, month = {01/2022}, pages = {14-16}, address = {Rotorua}, abstract = {Abstract Fertility is a fundamental phenotypic trait used for achieving optimal production efficiency and, no easily adoptable or precise tools are currently available. In this study, anogenital distances (AGD; anus to clitoris - AC and anus to fourchette - AF) were measured twice from 80 Merino ewes and 80 ewe hoggets to predict fertility. Fertility was measured by evaluating the pregnancy scanning results. Measurements of ADG were performed by using digital callipers and high-resolution images. Overall means of measures were greater for the AF in pregnant ewes compared to dry ewes and no association was found for the AC distance except being shorter for hoggets with callipers. The relationship found between one of the AGD, the AF, and pregnancy status demonstrates the potential to use this trait as a cost-effective method for estimation of fertility that can be easily adopted by producers, particularly in hoggets. Keywords: breeding, clitoris, imaging, pregnancy status, sheep }, issn = {1176-5283}, author = {LJ Dunstana and ML Hebarta and FD Briena and SA McCoard and M Caetano} } @article {3672, title = {BRIEF COMMUNICATION: The Efficacy of Natural Substances to Protect Dietary Glutamine from Ruminal Degradation}, journal = {New Zealand Journal of Animal Science and Production}, volume = {83}, year = {2023}, month = {01/2023}, pages = {17-19}, address = {Rotorua}, abstract = {

In ruminants, the rumen protection of amino acids is required to prevent microbial degradation and increase the portion of undegradable dietary protein; therefore, increasing the total concentration of amino acids absorbed in the small intestine. The conditionally essential amino acid, glutamine, is vital to an array of biological processes throughout the body. The objective of the current study was to validate and optimise the use of two natural substances (NS1 and NS2) to rumen-protect glutamine from microbial degradation. Encapsulated glutamine has been tested in triplicate using an in vitro approach. It was concluded that, both natural substances provided protection to glutamine resulting in a 33.83\% and 10.66\% decrease in ammonia release with NS1 and NS2 respectively. Keywords: amino acids, in vitro test, protein, rumen microorganisms, ruminants

}, issn = {1176-5283}, author = {LP Carlyon and TR Boyce and LJ Flanagan and RC Alves and K Petrovskix and M Caetano} } @article {4164, title = {NEW ZEALAND JOURNAL OF AGRICULTURAL RESEARCH SPECIAL ISSUE: A snapshot of research in animal production in New Zealand.}, volume = {83}, year = {2023}, abstract = {

A special edition of\ the New Zealand Journal of Agricultural Research (NZJAR) has been compiled from the 83rd conference of the New Zealand Society of Animal Production (NZSAP) held in Rotorua in November 2023.\ 

The papers in this special edition bring together multiple disciplines that were presented at the conference.\ 

Please use the link below to access the contents page for the special issue from the NZJAR website.

Special issue: A snapshot of research in animal production in New Zealand.

}, author = {NZJAR} } @article {3672, title = {Analysis of ewe body condition scores from selected flocks in the North Island of New Zealand}, journal = {New Zealand Journal of Animal Science and Production}, volume = {82}, year = {2022}, month = {01/2022}, pages = {28-32}, address = {Online}, abstract = {

Ewe body condition score (BCS) is known to be associated with many ewe production traits. Descriptive and multivariate analyses were undertaken on existing datasets comprising 266,405 BCS observations from 86,444 individual two-tooth and mixed-age ewes on six commercially managed sheep farms in the North Island of New Zealand. The BCS observations were collected at pre-breeding, pregnancy diagnosis, set-stocking and weaning between the years 2009-2021. Overall, the majority of BCS observations were 2.5 or 3.0 while 9.7\% were BCS \<2.5. At the key management times of pre-breeding and set-stocking, when it is recommended that ewes should be BCS 3.0 and above, 39\% and 50\% respectively of ewes were BCS \<3.0. Mixed-age ewes had greater odds of being BCS \<2.5 compared with two-tooth ewes, but with variation between BCS observation time, farm and year. While these data are from only six farms, if they are indicative of other North Island sheep farms they demonstrate significant room for improvement in individual ewe BCS for optimal production.

}, issn = {1176-5283}, author = {Ridler AL and Flay KJ and Kenyon PR and Lawrence KE and Corner-Thomas RA} } @article {3672, title = {BRIEF COMMUNICATION: Behaviour and physiology of lambs with gastrointestinal nematode parasitism}, journal = {New Zealand Journal of Animal Science and Production}, volume = {82}, year = {2022}, month = {01/2022}, pages = {104-107}, address = {Online}, abstract = {The behaviour and physiology of lambs with gastrointestinal nematode infections (GIN) was evaluated. Thirty 8-month-old Romney wethers were assigned to one of two treatments (n=15/treatment) trickle dosed with either 1500 infective third stage larvae 3 days/week for 6 weeks (27,000 total L3; challenged), or water 3 days/week for 6 weeks (control). Blood and faecal samples were collected weekly during the study. Lipidomics were performed on plasma samples. Behaviour was observed from video-camera recordings once weekly over the study. At treatment week 4, specific triglycerides were elevated in the challenged lambs compared to controls (P<=0.05). Faecal egg counts were higher in challenged than control lambs from treatment week 4 (154 epg; P<=0.001). Challenged lambs had higher standing bouts at week 4 than baseline (5.6 bouts) whereas there were no differences in standing bouts for control lambs between baseline and week 4. Triglycerides and standing behaviour show promise for early identification of GIN.}, issn = {1176-5283}, author = {Hempstead MN and Waghorn TS and Gibson MJ and Sauermann CW and Ross AB and Cave VM and Sutherland MA and Sutherland IA} } @article {3672, title = {Comparison of associations between estimated breeding values and cow survival in herds being milked once or twice a day}, journal = {New Zealand Journal of Animal Science and Production}, volume = {82}, year = {2022}, month = {01/2022}, pages = {93-98}, address = {Online}, abstract = {The objective of this study was to investigate the link between estimated breeding values (EBV) for selected traits, including Traits Other than Production (TOP), and cow survival in herds milked once-a-day (OAD), and to contrast with herds milked twice-a-day (TAD). After filtering, data from 234 OAD herds (71,321 cows) and 234 TAD herds (75,123 cows) were extracted from the Dairy Industry Good Animal Database between 2007 and 2021. Cow survival from parities 1 to 2, 2 to 3, 3 to 4, 4 to 5 and 5 to 6 (S12, S23, S34, S45 and S56) were modelled within each milking frequency and age parity group, with trait EBVs fitted as covariables and the fixed effect of herd-year, using a generalised linear model with a gaussian kernel. The survival rate in OAD cows was higher than in TAD cows in S12 and less in S34 to S56. Udder support EBV became important in older cows (S45 and S56) but there were no significant differences between OAD and TAD herds. Compared to OAD herds, Fertility EBV had a greater effect on survival in TAD herds up to S34, as did Body Condition EBV for S12. Conversely, milk Volume, Fat, Protein and Somatic Cell Score EBVs had smaller effects on survival in TAD herds. Our results do not contain evidence that warrant greater selection pressure on functional traits in OAD systems relative to TAD to enhance animal survival. When selecting sires, selection pressure could be reduced on some traits, such as Fertility and Body Condition, in OAD systems, with a greater emphasis placed on production and milk composition.}, issn = {1176-5283}, author = {Edwards JP and Zhang X and Stachowicz K and Waters ACL and Amer PR} } @article {3672, title = {A comparison of the performance Romney and Wiltshire cross lambs to weaning}, journal = {New Zealand Journal of Animal Science and Production}, volume = {82}, year = {2022}, month = {01/2022}, pages = {45-49}, address = {Online}, abstract = {

New Zealand coarse-woolled sheep farmers today barely recover the costs of shearing. One option is to introduce a self-shedding breed such as the Wiltshire. A strategy to transition to a Wiltshire flock is to cross a ewe flock with Wiltshire rams and in subsequent years backcross with Wiltshire rams. The first year of a long-term study found the performance of first cross Wiltshire progeny were not different to the base Romney flock in terms of birth weight and growth to weaning. The ewe lambs from this first breeding were then bred as ewe lambs to Wiltshire rams in late April 2021 to generate {\textthreequarters} Wiltshire lambs. There were no differences (P\>0.05) in fertility or fecundity between the {\textonehalf} Wiltshire cross or Romney ewe lambs. There were no differences in birth, docking or weaning weight with the exception that single-born {\textthreequarters} Wiltshire cross lambs had higher growth (P\<0.05) from birth to weaning than their Romney counterparts. This effect was not (P\>0.05) observed in twin lambs. Combined these results indicate to date that there are no negative impacts of introducing Wiltshire rams to a mixed-age Romney ewe flock in relation to ewe performance to 15 months of age and the performance of their {\textthreequarters} progeny to weaning.

}, issn = {1176-5283}, author = {Corner-Thomas RA and Ridler AL and Kenyon PR and Andrews CJ and Burnham DL and Blair HT and Morris ST} } @article {3672, title = {Comparison of two milk replacer formulations on the growth, health and purchased feed costs of artificially rearing male dairy-sheep lambs using a restricted milk intake feeding system and early weaning}, journal = {New Zealand Journal of Animal Science and Production}, volume = {82}, year = {2022}, month = {01/2022}, pages = {7-13}, address = {Online}, issn = {1176-5283}, author = {McCoard SA and Birch D and Hea, S-Y and Maclean P} } @article {3672, title = {Deer seasonal growth pathways}, journal = {New Zealand Journal of Animal Science and Production}, volume = {82}, year = {2022}, month = {01/2022}, pages = {50-56}, address = {Online}, abstract = {Red deer are seasonal and generally experience a period of low growth in winter. Previous research has demonstrated that individuals vary in the degree of their seasonality. Mechanisms that drive the differences in seasonality are not well understood. Six sires paired by 12-month weight estimated Breeding Value (eBV) but with contrasting seasonality were used to generate progeny to investigate the mechanisms that influence seasonal growth. Progeny were fed ad-lib on pasture year-round to allow expression of genetic potential with liveweight monitored fortnightly. Feed intake and efficiency were estimated during a 10-day period in each season. Analysis of seasonal liveweight gains indicated that predicted seasonal growth rates were repeatable within sire lines. Significant differences within paired sire lines in growth rates were expressed during winter for the two lower 12-month weight eBV paired groupings. Winter intakes were estimated to be lower than spring intakes although absolute values were considerably higher than expected. Variations in estimated feed efficiency between sire-line pairings were significant in all seasons apart from summer however, more research is required to correlate this estimation technique against actual feed efficiency. This research demonstrated that variation in the degree of seasonality between sires does exist and could be exploited for management decisions.}, issn = {1176-5283}, author = {Thompson BR and Stevens DR and Ward JF and Dodds KG and Asher GW} } @article {3672, title = {Does silage containing Plantain affect the urination behaviour and urinary nitrogen of dry cows grazing diverse or conventional pasture?}, journal = {New Zealand Journal of Animal Science and Production}, volume = {82}, year = {2022}, month = {01/2022}, pages = {14-21}, address = {Online}, abstract = {

The objective of this study was to investigate the effect of diverse silage containing plantain on urination behaviour and urinary and faecal nitrogen (N) concentration of dairy cows when grazing standard ryegrass-white clover (RGWC) or diverse pasture containing plantain. Four groups of six non-lactating dairy cows were balanced and randomly assigned to one of four dietary treatments in a 2 {\texttimes} 2 factorial design: RGWC pasture plus RGWC silage; RGWC pasture plus diverse silage containing plantain; diverse pasture plus RGWC silage; diverse pasture plus diverse silage. Urination behaviour (frequency and volume) was continuously measured for a minimum of 24 hours on four cows per treatment using the Lincoln University PEETER V1.0 sensor. There was no silage or silage {\texttimes} pasture type interaction effects on urination behaviour, though diverse pasture regardless of silage increased daily urination frequency (p=0.046) and daily urine volume (p=0.003) of cows by 27\% and 31\% respectively, compared to RGWC. Spot urine N\% concentration was similar among treatments, but faecal N\% tended (p=0.07) to be higher in cows grazing diverse pasture compared to those grazing RGWC with no silage type effect. Unlike fresh plantain, silage containing plantain does not seem to alter urination behaviour or N excretion of dairy cattle. Keywords: Plantago lanceolata L; dairy cattle; winter study; urination frequency

}, issn = {1176-5283}, author = {Brown TM and HMGP Herath and Beckett BP and Bryant RH and Al-marashdeh O} } @article {3672, title = {Does the source of drinking water (bore vs town supply) influence water intake, milk production and cow drinking preferences?}, journal = {New Zealand Journal of Animal Science and Production}, volume = {82}, year = {2022}, month = {01/2022}, pages = {33-38}, address = {Online}, abstract = {

Cows are sensitive to drinking water quality, however, little is known about the perception of bore water that sometimes contain high concentrations of natural contaminants, such as iron and manganese. Our aim was to investigate if providing drinking water from town supply compared with unfiltered bore water would influence water intake, milk production and cow preferences. Four groups of cows (50 cows/group) milked once-a-day in autumn were offered either town supply water or unfiltered bore water for two weeks, before changing treatment for another two weeks in a cross-over design. Group water intake and individual milk production was measured daily (n=4 groups/treatment). Water source did not influence water intake or milk production (P>=0.641). A preference study on a subset of animals was undertaken after the initial trial period in which two groups of cows (n=2, 20 cows/ group) had free access to both water sources simultaneously for three days. Cows preferred to drink the unfiltered bore water compared to town supply (descriptive data). It is likely that the cows{\textquoteright} previous experience with drinking the unfiltered bore water influenced the results. The cows may also have perceived components of the town supply aversive compared to the bore water to which they were accustomed.

}, issn = {1176-5283}, author = {K, Sch{\"u}tz and Huddart F and Hardie E} } @article {3672, title = {Drinking behaviour of ewes with access to a water trough during summer and autumn - a preliminary examination}, journal = {New Zealand Journal of Animal Science and Production}, volume = {82}, year = {2022}, month = {01/2022}, pages = {69-76}, address = {Online}, abstract = {Three observational studies were conducted to determine the water intake behaviour of ewes during the summer of 2017 and autumn of 2018 in the Manawatu and summer of 2021 in the Wairarapa. In each study, ewes were offered ad-libitum access to water from reticulated water troughs with video cameras recording footage of ewe drinking behaviour. Ewes were fitted with a uniquely numbered collar and spray marked with an identification number on their flank. Proximity of ewes to the water trough was determined using Bluetooth technology. Maximum daily temperatures ranged between 17.2 and 25.5{\textdegree}C in study 1, 9.9 and 23.6{\textdegree}C in study 2 and 16.0 and 28.1{\textdegree}C in study 3. Pasture moisture content was greater than 70\% in both the Manawatu studies and less than 60\% in the Wairarapa. Eighty percent of ewes in 2017 and 45\% in 2018 were not observed to drink from the water trough at any time in the Manawatu, although, there was considerable intra-animal variation. In the Wairarapa, all ewes were observed to drink during the study on between one and 14 occasions. These studies suggest that ewe drinking behaviour showed considerable variation between individuals and is likely dependent on the environmental conditions and pasture moisture content.}, issn = {1176-5283}, author = {Corner-Thomas and Bunyaga AS and Draganova I and Burkitt L and Kenyon PR} } @article {3672, title = {Effect of breed on bone morphology in the distal metacarpus epiphysis of mature Angus and Angus crossbred cows}, journal = {New Zealand Journal of Animal Science and Production}, volume = {82}, year = {2022}, month = {01/2022}, pages = {82-87}, address = {Online}, abstract = {There are variations in stature between beef and dairy breeds (and their crosses) which are an indirect result of genetic selection and farm management for different production objectives. The aim of this experiment was to examine the effect of breed on bone morphology in the distal epiphysis of the metacarpus. The metacarpus was collected from 9.5-year-old Angus (AA), Angus-Friesian crossbred (AF), Angus-Jersey crossbred (AJ) and Angus- (Friesian cross Jersey) crossbred (AK) cows. Bone morphology in the epiphysis was assessed using peripheral quantitative computed tomography (pQCT) for the medial and lateral condyles of the epiphysis 7 mm from the distal metacarpus. The greater total bone cross-sectional area of AA and AF could be associated with minimising strain on the articulating surface of the metacarpus due to greater joint surface area. Therefore, the greater total bone cross-sectional area may be an indirect result of a greater level of muscularity in beef breeds with a heavier mature weight.}, issn = {1176-5283}, author = {Gibson MJ and Hickson RE and Dittmer KE and Back PJ and Schreurs NM and Rogers CW} } @article {3672, title = {Evaluating loafing surfaces for off-paddock facilities on New Zealand dairy farms}, journal = {New Zealand Journal of Animal Science and Production}, volume = {82}, year = {2022}, month = {01/2022}, pages = {22-27}, address = {Online}, abstract = {Off-paddock wintering facilities need loafing surfaces that meet animal welfare requirements. Our objectives were to establish relationships between dairy cow behaviour and firmness (comfort) and traction (non-slip) across four different loafing surfaces. The four surfaces were post peelings (woodchip), a 50 mm shredded rubber playground surface with 6 mm geotextile overlay (NUMAT), a 25 mm rubber and plastic chip sports turf underlay with 6 mm geotextile overlay (Tiger Turf), and 25 mm {\texttimes} 1 m2 interlocking rubber matting (NUMAT). Average daily cow lying times were 11.5, 11.0, 10.5 and 8.0 hours/day for post peelings, shredded rubber, rubber/plastic chip, and rubber matting, respectively. A Clegg hammer impact soil tester (2.25 kg) used for mechanical measures of firmness (comfort) showed a strong negative curvilinear relationship with lying times. A Rotational Traction Tester for measuring traction (non-slip) indicated the least to most slippery surface was post peelings followed by shredded rubber, rubber/plastic chip, and finally, rubber matting, which aligned with anecdotal observations of slipping events. Threshold values for these mechanical tests are proposed that will help with evaluating innovative surfaces for cow comfort without the need for animal trials. }, issn = {1176-5283}, author = {Beukes PC and Dela Rue B and Dalley DE and McCall D} } @article {3672, title = {Factors that may lead to heat-stress in pigs during road transport}, journal = {New Zealand Journal of Animal Science and Production}, volume = {82}, year = {2022}, month = {01/2022}, pages = {1-6}, address = {Online}, abstract = {A preliminary observational study was undertaken to examine the effect of road transport on finisher pigs that were being transported to an abattoir in New Zealand. Temperature and humidity within a stock-truck were recorded during multiple trips over a three-year period and a video camera was employed to observe the behaviour of the pigs that were being transported. The videos produced were used to establish the times at which open-mouth breathing (OMB; an indicator for heat-stress in pigs) commenced. The videos revealed that OMB was found to occur throughout the year, including during the winter months, but that it occurred mostly during stationary periods when the truck stopped for driver breaks. A temperature-humidity index was utilised to ascertain what may have triggered the OMB and it was observed that the behaviour typically started when that index reached 72. The study suggests that the welfare of pigs may have been compromised by heat-stress over many of the journeys that were monitored. Keywords: heat-stress; pigs; temperature-humidity index; transport stress}, issn = {1176-5283}, author = {Dobinson SSA and Hickford JGH} } @article {3672, title = {Genetic parameters for velvet antler of farmed red deer and wapiti}, journal = {New Zealand Journal of Animal Science and Production}, volume = {82}, year = {2022}, month = {01/2022}, pages = {77-81}, address = {Online}, abstract = {

Deer breeding in New Zealand has historically paid little attention to quantitative genetic methods to improve the cut weights of velvet antlers. To provide enhanced breeding values for velvet antlers genetic parameters were estimated for DEERSelect. Velvet antler weight data was obtained from 21 red deer and 7 wapiti breeding studs and uploaded to DEERSelect. These data consisted of \> 50,000 records from 25,087 individuals and 1,419 sires. Mean velvet weights ranged from 2.71 ({\textpm}1.01) at 2-years, to 5.79 ({\textpm}1.98) at 10-years of age. Estimates of heritability at different ages were moderately high (0.33-0.44), but lower than previously reported estimates. Genetic correlations were high at all ages, phenotypic correlations were lower, both were similar to those reported previously. The genetic and phenotypic correlations between 12-month liveweight and 2-year-old and mature (i.e., >= 3 -year-old) velvet weights were low (0.15 {\textpm} 0.03, 0.02 {\textpm} 0.03) and low-moderate respectively (0.24 {\textpm} 0.08, 0.18 {\textpm} 0.01). These updated genetic parameters encouraged an update of the DEERSelect velvet module. The moderate heritability estimates should encourage breeders to make much more use of this quantitative genetic tool to breed more accurately for increased velvet antler weights.

}, issn = {1176-5283}, author = {Ward JF and McIntyre SB and Jopson NB and Newman S-AN} } @article {3672, title = {Genome-wide association studies for milk traits in New Zealand dairy sheep}, journal = {New Zealand Journal of Animal Science and Production}, volume = {82}, year = {2022}, month = {01/2022}, pages = {64-68}, address = {Online}, abstract = {The New Zealand dairy sheep industry has grown markedly in the last decades. With better genetics and management, companies have been able to improve key production traits. This study aimed to identify single nucleotide polymorphisms (SNPs) associated with milk traits in dairy sheep. We performed genome-wide association (GWA) analyses for milk yield, fat and protein content using data from commercial farms. We used 54,698 milk yield records and 24,891 fat and protein records from 4,590 and 2,823 ewes, respectively. Phenotypes were collected between August 2018 and April 2021 across three locations in New Zealand. They were adjusted for flock, age, lactation, lambing date, weeks in milk and permanent environment. Animals were genotyped with commercial SNP chips with 13,759 markers available after quality control. GWA models included the genomic relationship matrix, three principal components and genomic inflation correction for the p-values. We found four genome-wide significant associations for milk yield. These variants were mapped to eight genes, PDZRN4 (intron), EDEM2, PROCR, MMP24 (intron), EIF6, FAM83C, UQCC1, and HDAC9 (intron). Of these, PDZRN4, HDAC9 and MMP24 were associated with milk traits in previous studies. No significant associations were found for fat and protein content. Genes shown here are promising candidate genes, requiring validation in independent samples.}, issn = {1176-5283}, author = {Costilla R and Chan PB and Mcrae KM and McEwan JC and Dodds KG and Newman SA and Baird HJ and Henry H} } @article {3672, title = {Impact of maternal diet during late gestation and pre-weaning milk allowance on heifer growth and first lactation milk yield}, journal = {New Zealand Journal of Animal Science and Production}, volume = {82}, year = {2022}, month = {01/2022}, pages = {99-103}, address = {Online}, abstract = {A total of 60 Friesian x Jersey heifer calves were allocated to a 2{\texttimes}2 factorial design to investigate early life nutrition on growth and production. The first factor was the maternal treatments where dams were offered a low crude protein (7.8\% LCP) or moderate crude protein (13.6\% MCP) diet for the last 50 days of gestation. The second factor was the calf milk replacer (CMR) allowance to heifer offspring, which was either restricted (RES) or high allowance (HA) allowance (15 or 25\% of initial live weight, respectively). All calves were given colostrum for 4 days then, warmed CMR (150 g/L) in two equal feeds between days 5 and 39, after which all calves received the same 15\% allowance. Milk intake, liveweight gain and fecal score were recorded for 5 weeks. Calves were weaned off milk at 8 weeks of age. The HA treatment improved weaning weight (88 vs 79{\textpm}1.4 kg; P<0.001) and overall ADG pre-weaning (0.9 vs 0.8{\textpm}0.02 kg/day; P<0.001) compared to RES. There was no effect of maternal diet on pre-weaning growth or fecal score. There was limited statistical evidence of a long-term effect of early life nutrition on milk yield, though maternal nutrition appeared to be more important than pre-weaning nutrition on future milk production.}, issn = {1176-5283}, author = {Moonsan Y and Thomas C and McCoard SA and Hammond KJ and Edwards GR and Bryant RH} } @article {3672, title = {Modelling winter feeding practices with fodder beet in growing and dry dairy cattle}, journal = {New Zealand Journal of Animal Science and Production}, volume = {82}, year = {2022}, month = {01/2022}, pages = {39-44}, address = {Online}, abstract = {

The objective of this study was to use the Large Ruminant Nutrition System simulation (LRNS) model to evaluate inclusion of different proportions of fodder beet (FB) with several feed supplements to determine if these dietary combinations meet the nutrient requirements of dry cows and growing one-year-old (R1) heifers over winter. The LRNS simulations demonstrated deficiencies in Ca and P when diets contained 60 and 80\% of FB, especially for dry cows up to 21 days before calving and in R1 heifers. When FB comprised 60-80\% of the diet of R1 heifers, there was insufficient metabolisable protein to support maximum average daily gain and insufficient physically effective neutral detergent fibre (peNDF) in diets containing over 60\% FB. Diets containing more than 40\% FB had a negative rumen degraded protein balance (RDPB) and an excess non-fibre carbohydrate (NFC) concentration. Recommendations based on this modelling are for a maximum of 60\% FB in diets and forage supplements must provide sufficient crude protein (CP) as well as supplementation of Ca for R1 heifers and dry cows up to 21 days before calving and P for both dry cows and R1 heifers.

}, issn = {1176-5283}, author = {Jonker A and Dalley DE and Woods RR and Dynes RA and Pacheco D and Khan MA and Edwards JP and Hammond KJ} } @article {3672, title = {Ultrasound and histopathological studies of mastitis in hill-country ewes}, journal = {New Zealand Journal of Animal Science and Production}, volume = {82}, year = {2022}, month = {01/2022}, pages = {57-63}, address = {Online}, abstract = {

To determine the prevalence of mastitis in hill-country ewes, 1824 mixed-age Romney ewes in one flock were examined after weaning. Ninety-one (5\%) had clinical mastitis and, of these, 18 (1\%) had hard udder. Defects detected by ultrasound scanning (later confirmed by gross and histopathological examination) included abscesses and fluid accumulations in gland cisterns. Four months after weaning (2-3 months after diagnosis with mastitis) udders of 57 of the 91 culled mastitic ewes, randomly selected, were examined. Teat and gland parenchyma from 50 of these were later assessed histopathologically. Common findings were abscesses involving gland parenchyma and teats, pus in teat cisterns, mucosal polyps associated with lymphocytic inflammation in teat cisterns leading to stenosis or atresia, and mild-to-moderate lymphocytic inflammation in the gland interstitium. Results indicate that a significant proportion of ewes with severe and/or permanent mastitis damage such as hard udder can be identified by palpation and ultrasound soon after weaning, but some signs, notably hard udder, had disappeared by the time of post-mortem 2-3 months later.

}, issn = {1176-5283}, author = {Peterson SW and Collett MG and Kennedy EBG and Molenaar AJ and Nieper B} } @article {3672, title = {Use of organic waste streams to reduce the carbon footprint of New Zealand milk}, journal = {New Zealand Journal of Animal Science and Production}, volume = {82}, year = {2022}, month = {01/2022}, pages = {88-92}, address = {Online}, abstract = {

Life Cycle Assessment was undertaken to determine the impact of replacing purchased feeds and nitrogen fertiliser with New Zealand-sourced organic waste streams, on the cradle-to-farm-gate carbon footprint of a dairy farm. Five scenarios were assessed: 1) average New Zealand dairy farm, 2) supplementary feeds sourced from food waste, 3) mineral fertiliser replaced with chicken manure, 4) mineral fertiliser replaced with pig manure, 5) a combination of scenario 2 and 3. Diets in each scenario had the same total metabolisable energy and nitrogen content. Organic fertiliser was applied to ensure the same total nitrogen application per hectare. Replacing purchased feeds with waste from the food industry reduced the carbon footprint by 9\%, while replacing synthetic nitrogen fertiliser with chicken or pig manure resulted in a reduction of 1\%. Although this has shown the potential to reduce the carbon footprint of New Zealand milk while also reducing reliance on mineral fertilisers and imported feed, further work is required to determine feasibility and broader impacts.

}, issn = {1176-5283}, author = {Burggraaf VT and Mazzetto AM} } @article {3672, title = {BRIEF COMMUNICATION: Assessing the behaviour of pastoral poultry in an integrated system on a commercial dairy farm}, journal = {New Zealand Journal of Animal Science and Production}, volume = {81}, year = {2021}, month = {01/2022}, pages = {54-56}, address = {Online}, abstract = {The aim of this study was to determine the ranging behaviour and dispersal patterns of layer hens on a commercial pastoral dairy farm. One thousand seven hundred and sixty layers housed across three different flocks varying in age and shed type were observed weekly. Their outdoor area was classified into three zones based on the distance from their shed. Hens in each zone were observed for one hour at dawn, midday and dusk. There was no effect of time of day on bird dispersal patterns, but when hens were outdoors, the effect of location was significant (P<0.001) with the majority (26.77\%) of hens in the apron with the remaining visible hens observed in the outer range (21.99\%) and mid-range (16.33\%). In integrated pastoral systems with hens, management of hen excreta dispersal can be achieved through regular relocation of housing, feeders and water. Keywords: free-range; flock; location; zones; integrated farming system}, issn = {1176-5283}, author = {Smalling SS and Greig B and Bunt C and Tanner J and Bryant RH} } @article {3672, title = {BRIEF COMMUNICATION: Changes to cow behaviour when transitioning from twice a day to a 3-in-2 milking schedule}, journal = {New Zealand Journal of Animal Science and Production}, volume = {81}, year = {2021}, month = {01/2022}, pages = {51-53}, address = {Online}, abstract = {The objective of this study was to assess changes to cow behaviour when decreasing milking frequency from twice a day (TAD) to three milkings in two days (3-in-2). CowManager SensOor{\texttrademark} ear tags were attached to cows (n=29) for 15 days before, and 30 days after, transitioning to 3-in-2. To investigate general trends, paired t-tests were used to compare means between activity types (time spent active, highly active, not active, eating or ruminating) and milking frequency. After transitioning to 3-in-2 milking, the total time active was greater (+32.3 mins/cow/day; SEM 6.46), whilst the time spent eating (-16.2 mins/cow/day; SEM 7.57) and ruminating (-12.7 mins/cow/day; SEM 3.59) decreased. These differences were inconsistent between daylight and dark hours. These results indicate that the extra time spent in the paddock by the cows due to a 3-in-2 milking schedule was spent active, potentially due to social interaction and feed-searching behaviours, with a decrease in rumination and eating behaviours. Key words: Milking frequency; behaviour; activity; transition.}, issn = {1176-5283}, author = {Hall LS and Bryant RH and Edwards JP} } @article {3672, title = {BRIEF COMMUNICATION: Investigating the pattern of lameness in dairy goats across the first two years of life}, journal = {New Zealand Journal of Animal Science and Production}, volume = {81}, year = {2021}, month = {01/2022}, pages = {35-38}, address = {Online}, abstract = {Lameness is a painful condition with significant welfare and economic implications. There are few data about the high-risk periods of lameness in dairy goats, therefore, the aim of this study was to evaluate how lameness occurrence changes across the first two years of life. Eighty female goats of approximately five months of age were enrolled. Gait-scoring assessments were completed at 9, 13, 17, 21 and 25 months of age. Gait scores were assigned using a 5-point gait scoring system. As there were a low number of 3, 4 or 5 gait scores recorded, a binary outcome variable was created to compare non-lame (score 1) to an impaired gait (score >= 2). A logistic regression (PROC GLIMMIX) was used to test if there was a difference in the proportion of goats with an impaired gait among assessments. When compared with the nine-month assessment, the odds of a goat having an impaired gait were greater by a factor of 2.15 (95\% CI: 1.02 {\textendash} 4.54, P<0.05) at the 13-month assessment and 3.79 (95\% CI: 1.90 {\textendash} 7.57, P<0.001) at the 25-month assessment; as these assessments were both following kidding events, this suggests that parturition may increase the risk of lameness in dairy goats. Keywords: gait score; uneven gait; impaired gait; parturition; welfare}, issn = {1176-5283}, author = {Deeming L and Beausoleil NJ and Stafford KJ and Webster J and Zobel G} } @article {3672, title = {Can GreenFeed automated emissions monitoring systems measure methane output from young red deer grazing pasture?}, journal = {New Zealand Journal of Animal Science and Production}, volume = {81}, year = {2021}, month = {01/2022}, pages = {93-98}, address = {Online}, abstract = {and validation of methane-mitigation strategies for farmed deer requires a technology that can be deployed under grazing conditions. The GreenFeed automated emissions monitoring system (GAEM) integrated with an automated concentrate feeder has been successfully used to determine methane output from cattle but has not been tested with deer. The objective of this study was to evaluate large and small ruminant GAEM units with rising-yearling red deer, to determine if they would access the feed lure, and remain for sufficient duration in the hood of the unit to collect representative measurements of methane outputs. Groups of 14 mixed-sex red deer were used in three trials during spring of 2020. In each trial, approximately a third of individuals accessed the GAEM units after being habituated to the lucerne pellet lure, more than 85\% of visits were < 2 min. With further refinement of deer-training protocols and configuration of the GAEM, pasture-based methane outputs should be able to be measured for a proportion of any mob with access to the unit. Keywords: GreenFeed; red deer; methane}, issn = {1176-5283}, author = {Bennett CP and Ward JF and Jonker A} } @article {3672, title = {A comparison of the ewe reproductive performance of Romney ewes bred to Romney or Wiltshire rams and the growth of their progeny to weaning}, journal = {New Zealand Journal of Animal Science and Production}, volume = {81}, year = {2021}, month = {01/2022}, pages = {136-140}, address = {Online}, abstract = {This study reports the results of the first cross breeding of Romney ewes with Wiltshire rams as part of a grading-up transition. Romney mixed-age ewes were bred to either Romney (n=200) or Wiltshire rams (n=349) in March 2020. Ewe breeding pattern (cycle bred), reproductive performance (pregnancy and fecundity rates) and lambing performance (lambing rate, lamb birth and weaning live weight and lamb survival) were recorded. The reproductive performance of ewes bred to either Romney or Wiltshire rams showed few differences. There were no differences (P>0.05) in pregnancy, fecundity or lambing rates of ewes bred to either Romney or Wiltshire rams although minor differences (P<0.05) in the breeding pattern were observed. Lamb live weights at birth and in mid-lactation did not differ (P>0.05) among single, twin and triplet lambs sired by either Romney or Wiltshire rams, however at weaning Romney-sired triplet lambs were heavier than Wiltshire triplets (P<0.05). At weaning, a small percentage (1.6\%) of Wiltshire lambs showed early signs of fleece shedding. Combined, these results suggest that in this flock there was little impact of introducing Wiltshire rams to a mixed-age Romney ewe flock on ewe reproductive performance and the growth of the F1 progeny to weaning. Keywords: Wiltshire; Romney; reproduction; growth; shedding}, issn = {1176-5283}, author = {Corner-Thomas RA and Ridler AL and Kenyon PR and Blair HT and Morris ST} } @article {3672, title = {Defecation behaviour reduces horse{\textquoteright}s utilisation of pasture}, journal = {New Zealand Journal of Animal Science and Production}, volume = {81}, year = {2021}, month = {01/2022}, pages = {74-80}, address = {Online}, abstract = {Horses kept at pasture create focal areas with high-density of faeces (latrines), which under commercial conditions can account for 30\% of total pasture area. This New Zealand study observed the utilisation of pasture, and establishment of lawns and roughs within one paddock, intensively grazed (semi-set-stocked) alternately by three herds of mixed-age (mature), predominately Standardbred, horses. The paddock was grazed by horses 480 of 730 days, with mean stocking density of four horses per ha (2148 kg live weight/ha). Median grazing duration was 44 days (IQR 37-47 days). The median overall pasture cover for the study period was 1114 kg DM/ha (range 496-2191 kg DM/ha), lawns was 683 kg DM/ha (range 389-1822 kg DM/ha), and roughs was 2058 (range 753-3971 kg DM/ha). There was a trend for greater post-grazing estimated pasture growth rates in roughs relative to the lawns (P=0.054). Latrine areas constituted a median 31\% (IQR 24-33\%) of available pasture area, with up to two faecal-piles/m2. The results of the current study suggest that intensive semi-set-stocked management promotes the establishment of easily identified latrine areas of moderate faecal-pile concentration. These data can contribute to modelling the nitrogen-holding capacity of the soil, nitrogen leaching and the efficient utilisation of pasture of grazing horses. Keywords: equine; faeces; nitrogen; pasture}, issn = {1176-5283}, author = {Adams BR and Gee EK and Back PJ and Rogers CW} } @article {3672, title = {Do cows with facial eczema feel pain?}, journal = {New Zealand Journal of Animal Science and Production}, volume = {81}, year = {2021}, month = {01/2022}, pages = {122-128}, address = {Online}, abstract = {Facial eczema (FE) negatively influences production and welfare. One consequence of FE is reduced feed intake, which could possibly be a consequence of cows experiencing nausea or pain or both. The aim of this study was to evaluate the association of cortisol and acute phase protein (APP) concentrations (indirect measures of pain) with gamma glutamyl transferase (GGT) and bile acid concentrations (indirect measures of liver damage) in dairy cattle. Blood samples were collected from 2,080 lactating dairy cattle from seven farms that were affected by FE and located in the North Island of New Zealand. Blood samples were analysed for GGT, bile acid, cortisol and APP (serum ferroxidase (SF), serum amyloid A and haptoglobin) concentrations. Data were analysed using best subsets linear regression including farm as a factor and various other prediction variables. There was a significant positive relationship between GGT and bile acid (P<0.001, Adjusted R2=37.3\%), SF (P<0.001, Adjusted R2=27.4\%), and haptoglobin (P<0.001, Adjusted R2=1.9\%) concentrations, but not with cortisol. The positive association between GGT concentrations and APP (SF, haptoglobin) may partly reflect the degree of liver damage caused by sporidesmin intoxication, however, it could also suggest that animals with higher GGT levels are experiencing systemic inflammation and potentially pain. Keywords: acute phase proteins; facial eczema; gamma-glutamyl transferase; inflammation; pain}, issn = {1176-5283}, author = {Sutherland M and Huddart F and Cox NR and Cuttance E and Sch{\"u}tz K} } @article {3672, title = {Dominant mutation(s) for low fibre curvature in the wool of sheep}, journal = {New Zealand Journal of Animal Science and Production}, volume = {81}, year = {2021}, month = {01/2022}, pages = {112-116}, address = {Online}, abstract = {Two sires judged to have phenotypically lustrous wool as neonates were mated to ewes that did not exhibit lustre in their fleece as adults. Around half their progeny were lustrous as neonates. Wool characteristics of these progeny were measured on an optically based fibre diameter analyser (OFDA) when they were weaned and again as yearlings. There was a profound difference in mean fibre curvature (P<0.001) such that the lustrous phenotype had less curvature in both sire groups (22.8, 24.5{\textdegree}/mm) compared with the non-lustrous (67.5, 56.2{\textdegree}/mm) as lambs, and 29.8, 28.1{\textdegree}/mm compared with 74.1, 55.0{\textdegree}/mm as yearlings. Curvature of the sire groups was significantly different in concert with breed mix, Merino in one sire and Romney in the other, but only when their fleece was not lustrous. The greasy fleece of the lustrous yearlings was significantly lighter (1.8 vs 3.0 kg, P<0.05) than their non-lustrous contemporaries, while there was no significant difference in fibre diameter between the two phenotypes as lambs or yearlings. Fibre curvature is inexpensive to measure and well-defined, whereas lustre is a qualitatively assessed trait. These findings suggest {\textquotedblleft}low fibre curvature{\textquotedblright} would be a more appropriate name for the trait than {\textquotedblleft}lustre{\textquotedblright}. Keywords: lustre mutant; wool fibre; crimp; curvature}, issn = {1176-5283}, author = {Scobie DR and van Koten C and Richena M and Plowman JE and Harland DP} } @article {3672, title = {Effect of concurrent pregnancy on the persistency of lactation in dairy cows milked once a day}, journal = {New Zealand Journal of Animal Science and Production}, volume = {81}, year = {2021}, month = {01/2022}, pages = {99-105}, address = {Online}, abstract = {Persistency of lactation is a trait of economic importance in any dairy production system. The objective was to investigate the effect of concurrent pregnancy on the persistency of lactation in a commercial herd of dairy cows milked once a day. The data set included 1962 monthly herd-test records (total 8-9 tests per cow) of milk, fat, protein and lactose yield from 219 pregnant cows and 23 non-pregnant cows of different breeds and lactation number. The records were used to model lactation curves for pregnant and non-pregnant cows using random regression with a linear model (Wilmink function). This was not an experiment initially designed to examine the effects of pregnancy on persistency of lactation in dairy cows. Rather, in the course of normal farm operations, some cows became pregnant during lactation and others did not. Pregnancy did not affect the persistency of lactation of cows milked OAD. After conception, there was no difference in total yields between the two groups, but there was a trend that pregnant cows produced lower yields of fat (P=0.0519) and lactose (P=0.0884). This difference between our results and those of previous studies was probably because our cows were only milked once a day or because the data set was not suitable for testing the hypothesis. Further study is required to investigate persistence of lactation in pregnant and non-pregnant cows milked OAD. Keywords: pregnancy; lactation persistency; cows milked once a day}, issn = {1176-5283}, author = {Fu Y and Peterson SW and Lopez-villalobos N} } @article {3672, title = {Effect of farm system and milk urea phenotype on milk yield and milk composition of dairy cows in Canterbury}, journal = {New Zealand Journal of Animal Science and Production}, volume = {81}, year = {2021}, month = {01/2022}, pages = {196-200}, address = {Online}, abstract = {To investigate the effect of farm system, and cow selection for milk urea nitrogen (MUN), on milk yield and milk composition, a farmlet study was carried out between October 2018 and May 2019 in Lincoln, Canterbury. A farm system with a low stocking rate and low N fertiliser input (LSR, 2.9 cows/ha) sown with a conventional ryegrass clover and plantain diverse pastures was compared with a farm system with a moderate stocking rate and moderate N fertiliser (MSR, 3.9 cows/ha) using conventional ryegrass and white clover pastures and supplementing 3 kg DM/cow/d as crushed barley grain. Each farmlet had total herd size of 40 mixed-age HF x J spring-calving dairy cows which included six cows selected solely for a high MUN or a low MUN. There was no effect of farm system on milk fat, protein or lactose content but MUN was lower in LSR compared with MSR. Milk production was also lower for LSR (466 vs 429{\textpm}12.4 kg MS/cow/ha, P<0.05), owing to poorer quality diet in mid lactation. Cows selected for low MUN tended to produce less milk compared with high MUN cows (4478 vs 3987{\textpm}174 kg/cow, P<0.10) though this was partially offset by increased protein content in milk of low MUN cows. Farm system and animal selection for MUN have a greater impact on milk yield than on milk composition. Keywords: Plantago lanceolata; somatic cell count; multi-species pastures;}, issn = {1176-5283}, author = {Bryant RH and O{\textquoteright}Conner PO and Robic Y and Curtis J and Handcock RC and Al-marashdeh O} } @article {3672, title = {The effect of feeding fodder beet or kale during winter on growth and behaviour of rising-one-year-old dairy heifers}, journal = {New Zealand Journal of Animal Science and Production}, volume = {81}, year = {2021}, month = {01/2022}, pages = {81-86}, address = {Online}, abstract = {While fodder beet (FB) has been used by the dairy industry for winter grazing over the last 10 years, there is no published information on its effect on heifer performance. Farmers have recently expressed concern regarding the suitability of fodder beet for wintering growing dairy heifers due to the low crude protein (CP) content of the FB bulb. To compare liveweight gain and grazing behaviour, 191, 9- to 12-month-old heifers at the Southern Dairy Hub were offered either FB (n=93; HFR-FB) or kale (n=98; HFR-Kale), both with pasture baleage as a feed supplement, in winter 2019. Allocations were formulated to achieve similar energy intake, but HFR-Kale were offered a higher proportion of their diet as baleage. There were no differences in apparent DM intake, but HFR-FB consumed a diet with overall lower CP (11.4\%) than did HFR-Kale (13.4\%). Heifers in both treatments had a similar average daily liveweight gain (0.45 {\textpm} 0.083 kg/day) but neither group achieved the 0.6 kg/day average daily gain target for heifer growth. Differences were observed in eating and ruminating behaviour between the two groups, but more research is required to validate the measurement devices used in this study for animals grazing crop. The results indicate the challenges of achieving industry-recommended growth rates over winter in heifers grazing forage crops and highlight the importance of feed testing for nutritive value to ensure nutrient requirements are being met. Keywords: Live weight; Beta vulgaris; Brassica oleracea; allocation; intake; feed quality}, issn = {1176-5283}, author = {Harris P and Dalley DE and Bryant RH} } @article {3672, title = {Effects of alternative forages on nitrate leaching under intensive sheep grazing}, journal = {New Zealand Journal of Animal Science and Production}, volume = {81}, year = {2021}, month = {01/2022}, pages = {146-152}, address = {Online}, abstract = {There is increasing interest in the use of alternative forages to improve animal performance and reduce nitrogen (N) leaching on farms. A system-scale field trial, which included 20 hydrologically isolated drainage plots (800 m2 /plot) was carried out at Massey University{\textquoteright}s {\textquoteleft}Keeble{\textquoteright} farm to investigate the effects of forage type on ewe and lamb performance and the quantity of N lost in drainage. Four forage types (treatments) were studied: perennial ryegrass/white clover (RGWC), plantain/WC (PWC), Italian ryegrass/WC (IRWC) and swedes (Brassica). The forage types were included as ~24\% area of a self-contained farmlet, with the remaining area (~76\%) being RGWC. Ewes were weighed at mating, pre-lambing and weaning, and lambs were weighed at weaning. Drainage (mm) from each plot was measured using a tipping-bucket flow meter and sub-samples of water were analysed for nitrate-N, ammonium-N and total-N losses. The forage types had no effect (P>0.05) on ewe or lamb live weight at any occasion. The average nitrate-N losses for RGWC (0.77 kg N ha-1), PWC (0.45 kg N ha-1) and IRWC (0.56 kg N ha-1) treatments did not differ (P>0.05) and was lower than the brassica treatment (6.36 kg N ha-1). }, issn = {1176-5283}, author = {Maheswaran S and Cranston LM and Millner JP and Horne DJ and Hanly JA and Kenyon PR and Kemp PD} } @article {3672, title = {The effects of out-of-season breeding on plasma prolactin concentrations, wool production and lamb birth weight}, journal = {New Zealand Journal of Animal Science and Production}, volume = {81}, year = {2021}, month = {01/2022}, pages = {129-135}, address = {Online}, abstract = {Performance of autumn- and spring-lambing ewes was compared in a year-long trial. Ewes were shorn in November and mated to lamb in May or August. Midside wool samples and plasma were collected at seven-week intervals to determine wool-growth rate, fleece characteristics, and prolactin concentrations. Autumn lambs were lighter (P<0.001) at birth and weaning (3.92{\textpm}0.1; 15.6{\textpm}0.7 kg) than spring lambs (5.27{\textpm}0.1; 25.3{\textpm}0.7 kg). Plasma prolactin concentrations were high (150 ng/ml) at mating (Dec) of autumn-lambing ewes, but low (50 ng/ml) at mating (March) of spring-lambing ewes. Both groups exhibited periparturient prolactin surges, but in autumn-lambing ewes this created high plasma prolactin concentrations during early pregnancy when plasma prolactin is usually very low. In autumn-lambing ewes, clean fleece weights (3.75{\textpm}0.11 kg), midside wool growth over 345 d (374{\textpm}12 mg/cm2) and fibre diameter (39.8{\textpm}0.5 mm) were significantly higher (P<0.05) than those of spring-lambing ewes (3.26{\textpm}0.12 kg; 331{\textpm}14 mg/cm2; 38.2{\textpm}0.5 mm respectively) whilst bulk and colour did not differ. Bulk was higher (P<0.05) in single-bearing ewes (21.1{\textpm}0.4 cm3/g) than in twin-bearing ewes (19.2{\textpm}0.7 cm3/g). It is postulated that elevated plasma prolactin concentrations (at key times) are related to seasonal differences in birth and fleece weights. Autumn lambing is beneficial for wool growth but detrimental for lamb birth weight and growth. Keywords: out-of-season lambing; sheep; prolactin; wool growth; birth weight}, issn = {1176-5283}, author = {Peterson SW and Burnham DL and Morris ST} } @article {3672, title = {The effects of substituting autumn nitrogen fertiliser with gibberellic acid on feed supply and milk production}, journal = {New Zealand Journal of Animal Science and Production}, volume = {81}, year = {2021}, month = {01/2022}, pages = {190-195}, address = {Online}, abstract = {The aim of this study was to investigate the use of gibberellic acid (GA) to improve feed supply and milk yield in late lactation. A grazing study at Lincoln used 36 lactating, mixed-age, Friesian-Jersey cross dairy cows balanced over three un-replicated treatments of perennial-ryegrass and white-clover pasture treated with nitrogen (N) fertiliser as urea (50 kg N/ha), GA as ProGibb{\textregistered} SG (8 g GA/ha) or untreated (Control). Treatments were applied in late March 2014 and grazed over 12 days in May. There was no effect of treatment on herbage pre-grazing pasture mass (2058{\textpm}6.9 kg DM/ha, P=0.20), clover (3.6{\textpm}0.86\%, P=0.53), ryegrass (88.0{\textpm}2.33\%, P=0.24) or crude protein (CP) content (17.8{\textpm}1.60\%, P=0.31). All milk yield components: 14.6{\textpm}0.40 L/day, 1.4{\textpm}0.09 kg MS/cow/day, 5.4{\textpm}0.33\% fat and 4.4{\textpm}0.21\% protein were similar among treatment groups (P=0.71, 0.14, 0.16 and 0.06, respectively). Although faecal-N content of cows on GA pasture (3.72\% N) was higher (P<0.001) than cows on N-fertilised pasture (3.45\% N) there was no treatment effect (P>0.05) on urinary-N content (0.4 {\textpm} 0.02\% N) or N excretion in milk (101{\textpm}4.4 g N/cow/d). The lack of response to GA or N fertiliser highlights the importance of timing of growth promotants for late lactation. Keywords: perennial ryegrass; white clover; urea; growth promotants; dairy cow; milk production}, issn = {1176-5283}, author = {Miller ME and Edwards GR and Hague H and Bryant RH} } @article {3672, title = {Evaluation of existing equations to rank methane yields of sheep fed a range of fresh forages}, journal = {New Zealand Journal of Animal Science and Production}, volume = {81}, year = {2021}, month = {01/2022}, pages = {159-163}, address = {Online}, abstract = {The objective of the current study was to evaluate the performance of published equations to predict CH4 yield (g CH4/kg dry matter intake; DMI) in NZ sheep fed a range of fresh forages. A database with 182 NZ sheep CH4-yield treatment means was used to validate 17 published CH4-yield prediction equations. The CH4-yield predictions were evaluated using the square root of mean-square prediction error (RMSPE) and Lin{\textquoteright}s concordance correlation coefficient (CCC). The three prediction equations with the smallest error (<22\% of RMSPE) and the only ones with moderate CCC with observed CH4 yield were all based on data from animals fed forage only. These three models predicted CH4 yield based on DMI plus dietary neutral detergent fibre, and animal body weight, feed crude protein, or feed organic matter digestibility; and they performed better than the DMI only equations that are commonly used in national greenhouse gas inventory models and on-farm accounting models . Keywords: Meta-analysis; enteric methane; model validation; fodder crops}, issn = {1176-5283}, author = {Jonker A and Eug{\`e}ne M and de Klien C and Pacheco D and Vibart R} } @article {3672, title = {An evaluation of the FeedSmart app for feed planning in a controlled nutrition study}, journal = {New Zealand Journal of Animal Science and Production}, volume = {81}, year = {2021}, month = {01/2022}, pages = {87-92}, address = {Online}, abstract = {FeedSmart is an app designed for smartphones, tablets, and computers to help farmers make instant and accurate decisions around feed management. The accuracy of the FeedSmart app was assessed in an intensive controlled nutrition trial, over two consecutive years. The objective of the trial was to compare a maintenance (M) diet to a restricted diet, 0.6 of maintenance (R), over a 55-day period in sheep. In the first year, 48 animals were split between M and R groups. In the second year, 274 ewes were divided into light (L) and heavy (H) groups, then into M and R. The FeedSmart app was used to calculate the area required for both M and R groups. Based on previous data, restricted animals were expected to lose 7.1\% of their body weight over the 55-day period. The changes in year 1 M and R groups and year 2 HM and HR groups were not significantly different from the expected changes. The weight changes in the year 2 LM and LR groups were significant, but were within the errors associated with the calculations underlying the FeedSmart app. In these trials, the FeedSmart app provided an accurate tool for feed management. Keywords: FeedSmart; feed Planning; sheep; nutrition}, issn = {1176-5283}, author = {Peers-Adams JL and Smith P} } @article {3672, title = {The fate of calves born on New Zealand dairy farms and dairy farmer attitudes towards producing dairy-beef calves}, journal = {New Zealand Journal of Animal Science and Production}, volume = {81}, year = {2021}, month = {01/2022}, pages = {179-185}, address = {Online}, abstract = {Dairy calves that are not required as herd replacements provide an opportunity for beef production with a relatively low environmental footprint. A telephone survey of 262 New Zealand dairy farmers was conducted in October 2020 to gain insight into current mating and calving practices, and attitudes to dairy-beef breeding and rearing calves for beef. This number of respondents provided a margin of error of {\textpm}6\%. On average, per herd, 28\% of calves were kept as dairy replacements, 12\% were reared on-farm for beef, 15\% sold for beef rearing, 35\% sold to process as {\textquoteleft}bobby{\textquoteright} calves, 5\% euthanised and 4\% born dead or died. The largest barriers to producing more beef calves were uncertainty around their value, followed by calving difficulties with beef bulls. The main barrier to rearing more calves for beef was higher earnings for milk than for beef. However, 60\% of respondents agreed that the sector should aim to decrease the number of {\textquoteleft}bobby{\textquoteright} calves. This survey provides data for the development of cross-sector initiatives to increase dairy-beef integration and the utilisation of calves. These results provide a rich description of the current state of the sector and they suggest that at least 74\% of New Zealand beef production originates in the dairy industry. Keywords: dairy calf; dairy-beef; bobby calf; calf rearing; mating}, issn = {1176-5283}, author = {Edwards JP and Cuthbert S and Pinxterhuis JB and McDermott A} } @article {3672, title = {Genetic parameters for urination traits and their relationships with production traits of dairy cattle grazing temperate ryegrass and white-clover pastures}, journal = {New Zealand Journal of Animal Science and Production}, volume = {81}, year = {2021}, month = {01/2022}, pages = {153-158}, address = {Online}, abstract = {The objective of this study was to quantify genetic parameters of daily urination traits; urinary nitrogen (UN), urination volume (Uvol), urination number (Unum), average UN concentration (UNconc) and volume per urination event (VolEvent) including their genetic correlations with milk urea nitrogen concentration (MUN) and other production traits in New Zealand dairy cattle. Heritability estimates for urination traits measured on four consecutive days ranged from 0.17 to 0.35. Repeatability estimates ranged from 0.31 to 0.58, indicating that reliable prediction of urination measures would benefit from repeated measurement over a number of days. The heritability estimate for MUN was 0.29, similar to reports in the literature, whilst the estimate of repeatability (0.73) was greater than previously published values. Estimates of the genetic correlations between MUN and urination traits ranged from -0.39 to 0.41, however, due to the small number of animals in the current study, the confidence intervals were wide. The low genetic correlations may result from variation in voluntary feed intake from cow to cow that is a feature of pasture-based grazing systems. The results suggest that urination traits may be changed through selection. The low estimates of genetic correlations between MUN and urination traits suggest that MUN may not be a useful estimator of individual UN excretion in pasture-fed dairy cattle. Keywords: urine traits; milk urea}, issn = {1176-5283}, author = {Handcock RC and Box LA and Glassey C and Garrick DJ} } @article {3672, title = {Genome-wide association study of UV-protectant ambilateral circumocular pigmentation in Hereford cattle}, journal = {New Zealand Journal of Animal Science and Production}, volume = {81}, year = {2021}, month = {01/2022}, pages = {39-44}, address = {Online}, abstract = {Hereford cattle have a dominantly inherited white face that is characteristic of their breed. A small proportion of Hereford cattle present with regions of pigmentation around the eyes, known as ambilateral circumocular pigmentation (ACOP), which is hypothesised to provide UV-protectant properties to the underlying tissue. ACOP has been associated with reduced incidence of two diseases, bovine ocular squamous cell carcinoma, and bovine infectious keratoconjunctivitis, making it a desirable trait for selection. We conducted a genome-wide association study for ACOP in 605 American Hereford cattle using 43,789 genetic markers, and investigated the phenotypic association between face-colour and ACOP. The most highly associated variant from our genome-wide association study mapped to Chr6 g.71059814G>A and explains most of the variation for this trait. This variant falls in close proximity to the well-known coat-colour patterning gene KIT, suggesting it may be the causal gene for this trait. Our results suggest that ACOP is not directly influenced by face-colour, and may be influenced by non-additive genetic effects. These results provide an opportunity to select for Hereford cattle with ACOP, enhancing welfare, and reducing the incidence of bovine infectious keratoconjunctivitis and bovine ocular squamous-cell carcinoma. Keywords: Hereford cattle; ambilateral circumocular pigmentation; ocular squamous cell carcinoma; infectious keratoconjunctivitis; GWAS; pigmentation traits}, issn = {1176-5283}, author = {Jivanjia S and Koscha T and Littlejohn M and Garrick DJ} } @article {3672, title = {Genomic evaluations of sheep in New Zealand}, journal = {New Zealand Journal of Animal Science and Production}, volume = {81}, year = {2021}, month = {01/2022}, pages = {106-111}, address = {Online}, abstract = {Many New Zealand equine owners/stud managers rely on body condition to adjust feed supply for weight management, rather than objective weigh scales. This cohort observational study examined the inter-relationship of pasture supply with monthly BCS and live weight (LW) in three groups (n = 7, 8, 9) of grazing-horses of median 6/9 BCS (range 4-8). Dry-matter (DM) intake was estimated from weekly pasture mass (using rising-plate meter), monthly pasture cuts, and fortnightly LW records. Total pasture DM at the start of grazing ranged from 559 to 3511 kg DM/ha, and grazed lawns (nutritive areas) ranged from 364 to 2601 kg DM/ha. Total estimated DM offered (including hay when offered) ranged from 1.46 to 26.37 kg DM/horse/day (0.3\% to 5.3\% of horses LW). Within-horse maximum monthly gains and losses were 8\% LW and -13\% LW respectively. Median monthly BCS change was 0/9 (range -2/9 to 1/9). There was no significant association between monthly changes in LW and BCS, indicating BCS may lack the sensitivity to manage weight. During periods of reduced DMI (below estimated maintenance) there were no significant decreases in LW or BCS. These data implied that the horses may have altered transit time to improve the relative digestibility of the limited feed on offer. Keywords: horse; weight; body condition score; pasture; intake}, issn = {1176-5283}, author = {Lee AM and Newman S-AN and Dodds KG and Nilforooshan MA and Auvray B and McIntyre S and Campbell D} } @article {3672, title = {Grazing behaviour of young cattle around faecal pats}, journal = {New Zealand Journal of Animal Science and Production}, volume = {81}, year = {2021}, month = {01/2022}, pages = {63-67}, address = {Online}, abstract = {Young Holstein Friesian bulls grazed four mixed-contour paddocks for a duration of three days on ten occasions between December 2002 and March 2004. For the first seven grazing events, five faecal pats on both easy- (<25o) and steep-contoured land in each paddock were selected for monitoring herbage removal during the subsequent four to five grazing events. After each day of grazing, pasture height was measured at 5-cm intervals for 50 cm from the centre of each pat. The decrease in pasture height was converted to estimates of herbage dry matter removal. For the first three grazing events following pat deposition, avoidance of grazing herbage around pats was greatest on the first day of the three-day grazing duration. The mean distance of grazing from the centre of the pats was 21, 14, 10 and 7 cm for the first to fourth grazing events following deposition. Avoidance was greatest around pats that were deposited in late spring/early summer with little difference occurring between pats located on easy or steep land. Increased grazing pressure appeared to override the natural behaviour of young cattle to avoid grazing close to faecal pats. Grazing management of young cattle should ensure residuals of at least 1500 kg DM/ha in order to minimise the grazing of herbage surrounding faecal-pat areas which are highly contaminated with parasite larvae. Keywords: cattle; grazing behaviour; faecal pats; cattle parasites}, issn = {1176-5283}, author = {Boom CJ and Sheath GW and Burggraaf VT} } @article {3672, title = {Impact of casein- versus whey-based lamb milk replacers on growth and health of artificially reared lambs}, journal = {New Zealand Journal of Animal Science and Production}, volume = {81}, year = {2021}, month = {01/2022}, pages = {22-28}, address = {Online}, abstract = {High cost of milk proteins has driven development of cheaper whey-based milk replacer (WBMR) as an alternative to skim-milk (casein)-based milk-replacer (CBMR) for artificial-rearing of young ruminants. This study compared growth, antibiotic/anti-inflammatory use and mortality in lambs reared on either WBMR (n=138) or CBMR (n=151) in the first three weeks of rearing at commercial scale. There was a diet x rank interaction (P=0.001) whereby CBMR-fed single/twin and triplet/quad lambs had the highest average daily gain (ADG) independent of birth-rank (362 vs. 358 g/d respectively, SED=16.7) compared to WBMR-fed lambs where higher ADG was observed in triplet/quad compared to single/twin lambs (275 vs. 213 g/d respectively, SED=16.7). Males tended to have higher ADG than females (311 vs. 294, SED=9.7 g/d, P=0.064). Overall, there was a tendency for greater mortality (11\% vs. 4\%; P=0.055), and overall incidence rate (N/100 animal weeks) for use of antibiotics (4.43 vs. 1.27; P=0.073) and anti-inflammatories (4.59 vs. 1.59; P=0.099) in WBMR- than CBMR-fed lambs. These results highlight that CBMR under an ad-libitum milk-feeding regime supports greater ADG independent of birth-rank and reduces the incidence of disease in the first three weeks of life compared to WBMR. Furthermore, WBMR under an ad-libitum milk-feeding regime results in lower ADG of single/twin-born lambs compared to their triplet/quad counterparts. Keywords: lambs; artificial rearing; milk replacer; composition; growth; health; mortality}, issn = {1176-5283}, author = {McCoard SA and Ryrie J and MacDonald T and Hea S-Y and Pacheco D and Stevens D} } @article {3672, title = {Impact of winter near-maintenance or non-restricted feeding on growth and intramuscular fat content of yearling rams}, journal = {New Zealand Journal of Animal Science and Production}, volume = {81}, year = {2021}, month = {01/2022}, pages = {141-145}, address = {Online}, abstract = {There is increased interest in genetic improvement in intramuscular fat in lamb due to its positive association with meat quality. Live-animal measures such as ultrasound or computed tomography scanning can enable genetic selection. The optimum time at which such measurements should take place is unknown. This study investigated levels of intramuscular fat in year-old rams. During the winter of 2020, ram lambs were fed on either a just-above-maintenance pasture diet (JAM) (n=119) with a target weight gain of 50 g/day, or non-restricted feeding (GAIN) (n=120) with a target weight gain of 180-200 g/day, with all rams slaughtered after 10 weeks of differential feeding. Both groups of rams were fed a ryegrass-dominant pasture. The target for the GAIN group was achieved with an average growth rate of 182{\textpm}42 g/day (range 76 to 293 g/day), however, for JAM group the average growth rate was 24{\textpm}64 g/day (range -212 to 126 g/day), with a third of the animals losing weight. The JAM group were split according to whether they had gained (JAM {\textendash} Gain) or lost weight (JAM {\textendash} Loss) for the analysis. There were differences (P<0.001) at the time of slaughter in early spring in carcass weight between groups (23.7{\textpm}0.35, 19.5{\textpm}0.40 and 17.0{\textpm}0.47 kg for GAIN, JAM {\textendash} Gain and JAM {\textendash} Loss respectively). The levels of intramuscular fat were low across all groups compared to levels normally observed in 6-8-month old ram lambs and with further differences (P<0.001) between the three groups (2.1{\textpm}0.08, 1.9{\textpm}0.09 and 1.4{\textpm}0.10 kg for GAIN, JAM {\textendash} Gain and JAM {\textendash} Loss respectively). More work is required to understand management systems that allow improved expression of the trait. Additionally, careful consideration needs to be given to winter grazing management of all young stock, as there is considerable variability in individual animals handling of winter maintenance feeding. Keywords: lamb; maintenance feeding; intramuscular fat}, issn = {1176-5283}, author = {PL Johnson and Knowler K and Mcrae KM and Bain WE and Pile G and Craigie CR and Rowe SJ} } @article {3672, title = {Investigating the potential for global positioning satellite data to provide information on ewe behaviour around the time of lambing}, journal = {New Zealand Journal of Animal Science and Production}, volume = {81}, year = {2021}, month = {01/2022}, pages = {29-34}, address = {Online}, abstract = {Global positioning satellite (GPS) devices allow spatial-temporal data sets to be generated which can describe ewe movement around the time of lambing and can potentially be linked to traits of interest, such as the timing and location of lambing events and maternal outcomes including lamb weaning weight. Collar-mounted GPS units were fitted to 25 ewes during their anticipated lambing period. Lambing timing and site were estimated based on a minimum of twice-daily checks of the ewes. Lambing and GPS data were ultimately available for 15 ewes. From the resulting data set, several traits were calculated including the average distance deviation from the central point of the three-hour time block. During the birthing event (at a resolution of hours), the ewes changed their movement behaviour and remained close to the centralised point of the three-hour block. There were significant associations among the weaning weight of the ewes{\textquoteright} offspring (adjusted for rearing rank) and the GPS-derived traits: ewes that were comparatively inactive produced lambs with low weaning weights. Overall, this study demonstrates the potential of GPS-derived traits to be of relevance in studies investigating ewe behaviour around and after-lambing and its impact on production outcomes. Keywords: lambing; global positioning satellites; weaning weights}, issn = {1176-5283}, author = {PL Johnson and Welsh A and Knowler K and Pletnykov P} } @article {3672, title = {INVITED REVIEW: A review of the current sheep industry in New Zealand and opportunities for change to meet future challenges}, journal = {New Zealand Journal of Animal Science and Production}, volume = {81}, year = {2021}, month = {01/2022}, pages = {1-15}, address = {Online}, abstract = {

Like all farming systems, sheep operations face increasing economic, environmental, cultural, and social challenges, including climate change and consumer expectations about their food. Genetic improvement has the potential to help with these challenges. This review explores the importance of genetic improvement on welfare and disease traits in meeting these challenges. For all wool breeds, there is a need for traits such as being polled, having a short tail and having a bare breech and a bare belly to ensure an ethical outcome. Sheep that either seasonally lose their fleece, or do not grow wool, represent an opportunity. Predicted climate change poses significant animal-health challenges, including the internal parasite Haemonchus contortus, facial eczema, flystrike and pneumonia, that are likely to encroach on a wider geographic range. Given consumer expectations around reduced chemical inputs and improved animal welfare, genetic improvement will play a critical role in developing sheep that are more tolerant to such health challenges. While several key physical characteristics required for the future exist in minor breeds currently in New Zealand, their performance under a range of New Zealand commercial farming conditions has not been evaluated. Some overseas breeds, such as Katahdin and Barbados Blackbelly, may offer opportunities. Consideration needs to be given to the use of novel gene pools both within and outside the New Zealand sheep industry for it to be able to meet future challenges. To achieve this end, more information is needed about the overall merit of these novel breeds, to be able to identify the best strategy to take towards breeding sheep that address the future needs of the New Zealand sheep industry. Keywords: sheep; genotypes; breeding; future

}, issn = {1176-5283}, author = {PL Johnson and Newman S-AN and Mcrae KM and van der Weerden T and Brown M and Scobie DR} } @article {3672, title = {Live weight and bone growth from birth to 15 months of age in pure-bred and cross-bred Jersey and Friesian heifers}, journal = {New Zealand Journal of Animal Science and Production}, volume = {81}, year = {2021}, month = {01/2022}, pages = {45-50}, address = {Online}, abstract = { Live weight and liveweight gain of dairy heifers has been described in New Zealand and overseas, however, the change in stature and pattern of proximal and distal bone growth has, to date, received little attention. This study describes the proportional changes in stature with live weight, in a cohort of commercial dairy heifers (Holstein-Friesian, Jersey, and Holstein-Friesian-Jersey crossbred) from birth to 15 months of age. Comparisons of height, length, girth, and distal and proximal forelimb length (stature) revealed that at the same live weight, these parameters differed among breeds (P<0.05), however, the magnitude of the differences among breeds was consistently less than 1 cm. As heifer live weight increased, the contribution of the distal limb to increases in height decreased, which is consistent with knowledge that physeal closure in cattle occurs earlier in distal limb bones, such as the metacarpus, than in proximal limb bones, such as the humerus. In addition, the understanding of proximal and distal growth in cattle identifies when heifers are most susceptible to growth checks. Keywords: bone; stature; fracture; dairy heifer}, issn = {1176-5283}, author = {Gibson MJ and Rogers CW and Hickson RE and Dittmer KE and Back PJ} } @article {3672, title = {Optimising a panel of single nucleotide polymorphisms for genomic prediction in New Zealand sheep}, journal = {New Zealand Journal of Animal Science and Production}, volume = {81}, year = {2021}, month = {01/2022}, pages = {117-121}, address = {Online}, abstract = {A national genetic evaluation called the New Zealand Genetic Evaluation (NZGE) is undertaken weekly to support the genetic improvement of sheep via selective breeding in New Zealand (NZ). This is based on single step genomic best linear unbiased predictions (ssGBLUP), which allows animals that have genotypes and pedigree, or just pedigree, to be included in the same analysis (or evaluation). In theory, an optimal strategy is that the density and quality of SNPs used should be high enough to track all the haplotypes segregating in the population to be evaluated. Since genomic predictions have been used in NZ sheep, the content of the SNP panel used has decreased to a panel of 41K; despite that there are new SNP panels with more content available.. The effect of using this additional content and additional SNPs from an Ovine 600K chip was investigated using the trait fleece weight at 12-months. We found that a high density panel provided more accurate predictions. However, a SNP panel based on the 50K SNPs plus a relatively small subset of additional SNPs (e.g. from the 600K Chip), were as predictive as using the high density panel. We conclude that increased SNP density, beyond the 41K selected from the Ovine 50K SNP, chip will improve prediction accuracy. Our results suggest that the inclusion of SNPs from putative quantitative trait loci (QTL) may also improve prediction accuracy. However, further analyses will be helpful to distinguish the relative benefit to accuracy of increased SNP density across the genome and/or inclusion of SNPs associated with QTL. Keywords: sheep, genetics, genomics, breeding, ssGBLUP, genomic prediction}, issn = {1176-5283}, author = {Lee AM and Dodds KG and Newman S-AN and Campbell D and Clarke SM} } @article {3672, title = {Preliminary investigations into genetic variation in distance travelled by young sheep}, journal = {New Zealand Journal of Animal Science and Production}, volume = {81}, year = {2021}, month = {01/2022}, pages = {63-67}, address = {Online}, abstract = {In pastoral grazing systems, animals need to walk to obtain nutrients (pasture) and water, however, it is also thought that the distance an animal travels is further influenced by factors including the grazing behaviour of the animal, its health status and its general motivation for moving. The purpose of this research was to investigate the repeatability and genetic variation in the trait of distance travelled for New Zealand sheep. Data were collected using global positioning satellite (GPS) collars fitted to 422 animals from three different groups of animals (Group). The animals were allowed ad libitum grazing. Progeny from 44 sires were represented in the data set. The GPS collars were fitted for up to 17 days. Given between-day variability in distance travelled depending on paddock attributes (size and feed availability) all data were scaled to a constant mean. A univariate repeated measures model was fitted to the data using ASREML, with Group fitted within the model, and day within Group fitted as the repeated measure. The heritability estimate for daily distance travelled was 0.36{\textpm}0.09, with a repeatability estimate of 0.51{\textpm}0.03. The results indicate that distance travelled is a repeatable trait at the individual animal level and is under moderate genetic control. Keywords: sheep; GPS; distance travelled}, issn = {1176-5283}, author = {PL Johnson and Cullen N and Hickey SM and Knowler K and Bryson B and Hall M and Pletnykov P} } @article {3672, title = {Seasonal variation in pasture mass offered was not associated with changes in live weight, or body condition score, in three cohorts of horses}, journal = {New Zealand Journal of Animal Science and Production}, volume = {81}, year = {2021}, month = {01/2022}, pages = {16-21}, address = {Online}, abstract = {Many New Zealand equine owners/stud managers rely on body condition to adjust feed supply for weight management, rather than objective weigh scales. This cohort observational study examined the inter-relationship of pasture supply with monthly BCS and live weight (LW) in three groups (n = 7, 8, 9) of grazing-horses of median 6/9 BCS (range 4-8). Dry-matter (DM) intake was estimated from weekly pasture mass (using rising-plate meter), monthly pasture cuts, and fortnightly LW records. Total pasture DM at the start of grazing ranged from 559 to 3511 kg DM/ha, and grazed lawns (nutritive areas) ranged from 364 to 2601 kg DM/ha. Total estimated DM offered (including hay when offered) ranged from 1.46 to 26.37 kg DM/horse/day (0.3\% to 5.3\% of horses LW). Within-horse maximum monthly gains and losses were 8\% LW and -13\% LW respectively. Median monthly BCS change was 0/9 (range -2/9 to 1/9). There was no significant association between monthly changes in LW and BCS, indicating BCS may lack the sensitivity to manage weight. During periods of reduced DMI (below estimated maintenance) there were no significant decreases in LW or BCS. These data implied that the horses may have altered transit time to improve the relative digestibility of the limited feed on offer. Keywords: horse; weight; body condition score; pasture; intake}, issn = {1176-5283}, author = {Adams BR and Gee EK and Back PJ and Rogers CW} } @article {3672, title = {Sheep divergently selected for methane yield showed differences in meat fatty acid composition}, journal = {New Zealand Journal of Animal Science and Production}, volume = {81}, year = {2021}, month = {01/2022}, pages = {173-178}, address = {Online}, abstract = {The purpose of this work was to investigate whether 18-month-old rams from the methane selection lines differed in their levels of soft tissue depth over the 12th rib (GR, as a proxy of carcass fatness) intramuscular fat (IMF), and the fatty acid composition of IMF. The rumen is the site of microbial biohydrogenation of consumed plant fatty acids and synthesis of unique microbial body fatty acids. It is known that there are differences in the microbiome and fermentation characteristics of sheep selected for and against methane production (methane selection lines). When comparing the high and low lines several differences were found. Rams from low-methane-yield-selection lines tended to have lower GR (P<0.06) than those from high line rams, but there was no evidence for a difference in levels of IMF between the lines (P=0.77). There were, however, many significant differences in the fatty acid composition (as a \% of total fatty acids) of the IMF between the lines. The IMF from the low-methane-yield line had a significantly (P<0.05) higher proportion of branched-chain fatty acids, and fatty acids that are associated with the early stages of the biohydrogenation pathways in the rumen, specifically conjugated linoleic acid (CLA) and C18:1 t11 but with less C18:0 stearic acid (the end product of biohydrogenation) and a significantly higher proportion of C16:1 t9 which is produced through β-oxidation of C18:1 t11. These results provide insight into how differences in sheep from the methane-yield selection line may influence the fatty acid composition of their fat. Keywords: Methane; sheep; intramuscular fat; fatty acid composition}, issn = {1176-5283}, author = {PL Johnson and Agnew M and Jonker A and Hickey SM and McEwan JC and Bryson B and Dodds KG and Rowe SJ} } @article {3672, title = {TECHNICAL NOTE: Emissions improbable: how inappropriate use of the Global Livestock Environmental Assessment Model (GLEAM) can overestimate the emissions associated with dairy-production chains}, journal = {New Zealand Journal of Animal Science and Production}, volume = {81}, year = {2021}, month = {01/2022}, pages = {164-167}, address = {Online}, abstract = {In this paper we calculate the key differences between emissions estimates made using the Food and Agricultural Organisation of the United Nations (FAO) Global Livestock Environmental Assessment Model (GLEAM) and the New Zealand-specific analysis performed for the New Zealand Greenhouse Gas Inventory and the Fonterra Farm Gate Milk life-cycle analysis (LCA) that provides a proxy for all New Zealand milk production. We discovered that a wide range of factors can be responsible for more than a doubling of emissions calculated using GLEAM compared with emissions calculated using New Zealand-specific data. Such inappropriate use of GLEAM and the resulting conclusions have been used to undermine the efficiency of New Zealand production systems in publications such as Emissions Impossible. Keywords: Life cycle analysis; modelling; dairy processing}, issn = {1176-5283}, author = {Fletcher AJ and Sneddon NW and Hill JP} } @article {3672, title = {Temperament of hand-reared beef-cross-dairy cattle does not influence production traits}, journal = {New Zealand Journal of Animal Science and Production}, volume = {81}, year = {2021}, month = {01/2022}, pages = {57-62}, address = {Online}, abstract = {Abstract Evaluation of temperament of calves early in life is associated with growth and meat quality in extensively farmed beef cattle. However, the relationship between temperament and performance is unclear for hand-reared beef-cross-dairy calves. This experiment analysed temperament of 1077 Angus- and Hereford-sired cattle born to dairy-breed cows and hand-reared, and evaluated the value of these measurements as predictors of growth and meat quality traits. Cattle in this study were calm, with mean exit velocity (EV) between 0.76 and 1.15 m/s from 200 d to 800 d, crush score (CS) between 1.38 and 1.79 from 200 d to slaughter (1-5 scale), and measurements were highly correlated at all ages (P<0.05). Temperament at 200 d and 400 d was not related to growth, but CS was related to growth from 600-800 d (-0.011 kg/d for a 1-point increase in CS at 600 d, P<0.05). Temperament at 800 d or before slaughter was not related to meat ultimate pH or colour score. The small variation in temperament among animals was probably the consequence of cattle being acclimatised to the presence of humans due to hand-rearing and frequent handling. Therefore, temperament is unlikely to be an issue in hand-reared beef-cross-dairy cattle and should not influence growth and meat quality traits. Keywords: Artificial rearing; beef-on-dairy; beef production; crush score; exit speed; exit velocity; flight time}, issn = {1176-5283}, author = {Martin NP and Schreurs NM and Morris ST and Lopez-villalobos N and McDade JL and Hickson RE} } @article {3672, title = {Is there sire variation in seasonal liveweight gain of rising-yearling red deer?}, journal = {New Zealand Journal of Animal Science and Production}, volume = {81}, year = {2021}, month = {01/2022}, pages = {186-189}, address = {Online}, abstract = {Red deer exhibit the greatest seasonal control of nutritional physiology of farmed ruminants in New Zealand, highlighted by seasonal inappetence during winter, present in all sex and age classes. Four years of data from 2048 DNA-pedigreed mixed-sex progeny of 112 sires and 1069 dams from a red deer breeding stud were interrogated to investigate the hypothesis of sire variation in growth across seasons in rising yearlings. Analysis used 17145 live weights from progeny with >= 4 live weights to a minimum of 300 days of age. Estimates of the weights of all animals at the same age were calculated by fittinga restricted maximum likelihood model to adjust for multiple variables and create sire best linear unbiased predictions of rising-yearling growth. Liveweight gain was examined at 11 key seasonal ages. While overall post-weaning variation in liveweight gain was low (CV = 3.6-4.7\%), for seasonal periods it was higher (CV 9.2-15.5\%), with the greatest variability during the winter period (CV = 15.5\%). Ranking sires by the predicted proportion of gained live weight of their offspring over seasonal periods showed sire variation across different seasons. Such variation may be beneficial allowing genetic selection of animals to fit dferent farm systems.Keywords: red deer; Cervus elaphus; seasonality; growth; live weight}, issn = {1176-5283}, author = {Ward JF and Cox NR and McMahon CD and Stevens DR and Asher GW} } @article {3672, title = {Volatile fatty acids (VFA) in rumen samples collected pre-feeding had a stronger relationship with methane emissions in lambs fed graded levels of forage rape than VFAs in post-feeding samples}, journal = {New Zealand Journal of Animal Science and Production}, volume = {81}, year = {2021}, month = {01/2022}, pages = {168-172}, address = {Online}, abstract = {To investigate the effect of farm system, and cow selection for milk urea nitrogen (MUN), on milk yield and milk composition, a farmlet study was carried out between October 2018 and May 2019 in Lincoln, Canterbury. A farm system with a low stocking rate and low N fertiliser input (LSR, 2.9 cows/ha) sown with a conventional ryegrass clover and plantain diverse pastures was compared with a farm system with a moderate stocking rate and moderate N fertiliser (MSR, 3.9 cows/ha) using conventional ryegrass and white clover pastures and supplementing 3 kg DM/cow/d as crushed barley grain. Each farmlet had total herd size of 40 mixed-age HF x J spring-calving dairy cows which included six cows selected solely for a high MUN or a low MUN. There was no effect of farm system on milk fat, protein or lactose content but MUN was lower in LSR compared with MSR. Milk production was also lower for LSR (466 vs 429{\textpm}12.4 kg MS/cow/ha, P<0.05), owing to poorer quality diet in mid lactation. Cows selected for low MUN tended to produce less milk compared with high MUN cows (4478 vs 3987{\textpm}174 kg/cow, P<0.10) though this was partially offset by increased protein content in milk of low MUN cows. Farm system and animal selection for MUN have a greater impact on milk yield than on milk composition. Keywords: Plantago lanceolata; somatic cell count; multi-species pastures;}, issn = {1176-5283}, author = {Della Rosa MM and Janssen PH and Reid P and Sandoval E and Luo D and Pacheco D and Jonker A} } @article {3672, title = {An association between circulating copper concentrations and gammaglutamyl transferase activity in sheep after exposure to the toxin sporidesmin}, journal = {New Zealand Journal of Animal Science and Production}, volume = {80}, year = {2020}, month = {09/2020}, pages = {34-38}, address = {Online}, abstract = {Copper is a potent catalyst of the reaction in which sporidesmin generates damaging free radicals causing facial eczema in grazing livestock in New Zealand. This study sought to investigate whether circulating copper at the time an animal is dosed with the toxin, influenced the way the animal responds to sporidesmin and whether the action of sporidesmin on the liver in susceptible animals results in changes to circulating copper. Serum copper concentrations (CU) together with gamma glutamyl transferase (GGT) activity, an indicator of bile duct damage, were opportunistically collected on over 400 animals from nine flocks in which the animal{\textquoteright}s tolerance to sporidesmin was commercially assessed through measuring its response to a known dose of the toxin. The association between CU concentration before the animals were dosed and natural log transformed GGT activity measured 21 days after the animals had been dosed was not significant, but there was a suggestive (P=0.06) interaction between flock and CU. There was a significant positive association between natural log transformed GGT activity and CU concentrations measured 21 days after the animals had been dosed with the toxin (P<0.0001). For some individuals, the CU concentrations approached or met copper-toxicity thresholds (above 40 μmol/L). The specific biological mechanisms causing this association remain unknown, but given the role of copper in catalysing the sporidesmin reaction and the potential of toxic copper concentrations, further research is warranted. Keywords: sheep; facial eczema; copper; gamma glutamyl transferase}, issn = {1176-5283}, author = {PL Johnson and Amyes NC} } @article {3672, title = {Body condition scoring of sheep: intra- and inter-observer variability}, journal = {New Zealand Journal of Animal Science and Production}, volume = {80}, year = {2020}, month = {09/2020}, pages = {107-112}, address = {Online}, abstract = {Body condition scoring (BCS) is a hands-on tool that farmers can use to make decisions about their animal feeding and management. BCS, however, is a subjective measure of the muscle and fat cover of the lumbar spine. Observers, therefore, may show variability in scores both across time and from other observers. This study aimed to determine the intra- and inter-observer variation of both farmers and research technicians as part of a learning exercise of a farmer-learning group based at Massey University between 2011 and 2015. Nineteen farmers and three research technicians condition scored 45 mixed-age ewes on two consecutive days. Data from both farmers and technicians were analysed to determine the intra- and inter-observer variability using a weighted kappa. The results indicate that the majority of farmers and technicians had {\textquoteleft}excellent{\textquoteright} agreement (21 of the 22 observers had kappa values greater than 0.75) between days. Similarly, among pairs of observers the agreement was also {\textquoteleft}excellent{\textquoteright} (212 of 231 comparisons had kappa values greater than 0.75). The distribution of scores that contributed to each median condition score, however, indicated that lower scores (1, 1.5 and 2) has less variability than did higher scores (2.5 or greater). These results suggest that BCS is a robust farm-management tool that can be used with a high degree of repeatability. Keywords: body condition scoring; intra-observer variability, inter-observer variability}, issn = {1176-5283}, author = {Corner-Thomas RA and Sewell AM and Kemp P and Wood BA and Gray DI and Morris ST and Blair HT and Kenyon PR} } @article {3672, title = {BRIEF COMMUNICATION: Influence of birth rank on cause of lamb deaths prior to weaning}, journal = {New Zealand Journal of Animal Science and Production}, volume = {80}, year = {2020}, month = {09/2020}, pages = {21-23}, address = {Online}, abstract = {Post-mortem examinations were carried out on 1098 lambs that died between birth and weaning at 12 weeks of age to evaluate the causes of mortality in a high-fertility flock. These comprised 95\% of all lamb deaths from a total of 14732 lambs born over nine years. Starvation/exposure was the biggest cause of lamb deaths (26\%) followed by infection (20\%), hypoxia (16\%) and prenatal deaths (16\%). Prenatal deaths were 18\%, 12\% and 10\%; deaths due to hypoxia were 18\%, 15\% and 11\% and to starvation were 28\%, 26\% and 12\% for triplets, twins and singles respectively. There were no significant differences between birth ranks for deaths from infection. Keywords: mortality; litter size; birth rank; dystocia; starvation; prenatal; single; twin; triplet; survival; sheep}, issn = {1176-5283}, author = {Thomson BC and Smith NB and Ward KR and Muir PD} } @article {3672, title = {BRIEF COMMUNICATION: Meta-analysis of beef cow live weights in the mid-2000s}, journal = {New Zealand Journal of Animal Science and Production}, volume = {80}, year = {2020}, month = {09/2020}, pages = {128-130}, address = {Online}, abstract = {As traditional beef cows are rarely weighed, there are few quality data available on beef cow live weights. Data were collected on 12 farms between 2008/09 and 2009/10 as part of a project validating the data used in the New Zealand Agricultural Greenhouse Gas Inventory Model. Beef cow live weights were collected on both herd cows (mean 541.3 kg) and on cull cows (mean 552.6 kg). Carcass data were collected at slaughter to obtain better values for dressing-out (42.6\%). Carcass data provided by Landcorp Farming Ltd indicated that their average beef cow live weights were 568 kg in 2008/09. Carcass data collected by the B+LNZ Economic Service from 8511 beef cows in 2007/08 indicated that cow live weights averaged 537 kg. An unpublished MAF Sustainable Farming Fund study reported weights for 1120 cows across 15 farms and found an average beef cow live weight of 576 kg in 2006/07. An average across all these studies suggested that beef cow weaning weights between 2006 and 2010 were around 553 kg. Keywords: beef cow; liveweight; dressing-out \%}, issn = {1176-5283}, author = {Thomson BC and Smith NB and Muir PD} } @article {3672, title = {BRIEF COMMUNICATION: The behaviour of sheep around a natural waterway}, journal = {New Zealand Journal of Animal Science and Production}, volume = {80}, year = {2020}, month = {09/2020}, pages = {124-127}, address = {Online}, abstract = {Access of cattle to waterways has been shown to be a potential cause of poor-water quality, due to nutrients and pathogens deposited via urination and defecation. In addition, cattle can pug the banks of waterways and, thus, cause sediment loss. Although government-imposed regulations to fence waterways currently only applies to dairy cattle in New Zealand, it is likely that some exclusion restrictions will apply to sheep and beef in the future. This is a concern, as there is very little research examining the behaviour of sheep around natural waterways in NZ. Video recordings were made to observe the interaction of mixed-age Romney ewes (n=40) with a natural waterway at Massey University{\textquoteright}s hill-country farm Tuapaka. Ewe behaviour and movements were monitored continuously for two weeks using GPS devices and motion-activated trail cameras. Ewes were offered reticulated water (week 2) or were restricted from accessing the water trough (week 1). Riparian zones were accessed by some ewes (n=20) whose behaviours observed appeared to be influenced by time of day and environmental temperature. When in the riparian areas, ewes spent 68\% of their time grazing, 15.9\% stationary and 2.2\% drinking. Access to the water trough had no effect (P>0.05) on the drinking behaviour of ewes. It was concluded that, during winter, although only a small number of sheep drank from waterways, ewes accessed riparian zones to graze. Keywords: behaviour; ewes; waterways; riparian areas}, issn = {1176-5283}, author = {Bunyaga AS and Corner-Thomas RA and Burkitt LL and Draganova I and Kenyon PR} } @article {3672, title = {Changes in live weight and fleece characteristics during the lifetime of three breeds of New Zealand feral sheep that differ in fleece type}, journal = {New Zealand Journal of Animal Science and Production}, volume = {80}, year = {2020}, month = {09/2020}, pages = {117-123}, address = {Online}, abstract = {Live weight after joining and nine fleece characteristics were recorded throughout the lifetime of flocks of Hokonui, Campbell Island and Raglan sheep grazing at Whatawhata and Winchmore Research Centres between 1991 and 2004. The wool characteristics were measured in 585 individual wool samples collected at shearing from 90 breeding ewes sampled between one year of age and up to 12 years of age. Data on live weight, fleece weight, staple length, mean and variability of fibre diameter, fibre curvature, crimping and core bulk were analysed after adjustment for effects of grazing location and reproductive performance during the previous year. The three flocks differed in all measured characteristics, with all except live weight, mean fibre curvature and core bulk exhibiting a significant flock by age interaction. Live weight attained a maximum at six years of age, while greasy fleece weight and staple length decreased after two years of age. Core bulk decreased after three years of age. Fibre curvature decreased and time to form a crimp increased throughout the sheep{\textquoteright}s life. Fibre diameter variability between and along fibres showed a variable age response between flocks. The three feral flocks exhibited a different age response to continuously farmed breeds. Keywords: fleece characteristics; age effects; Hokonui; Campbell Island; Raglan}, issn = {1176-5283}, author = {Sumner RMW and Scobie DR and O{\textquoteright}Connell D and Henderson HV} } @article {3672, title = {Deer Industry Advance Parties: farmer groups lead practice change for improved profit}, journal = {New Zealand Journal of Animal Science and Production}, volume = {80}, year = {2020}, month = {09/2020}, pages = {161-165}, address = {Online}, abstract = {The NZ deer industry{\textquoteright}s {\textquoteleft}Passion2Profit{\textquoteright} productivity improvement programme, launched in 2013, established {\textquoteleft}Advance Parties{\textquoteright} (APs) to improve profitability among New Zealand deer farmers. Animal performance on farms was highly variable, and sometimes well below potential productivity, despite a large body of knowledge from prior research investments aimed at optimising animal performance. APs are small groups of like-minded farmers focussed on helping each other implement changes in their businesses. The benefits of these changes are disseminated to the wider deer farming community through various industry communications and regional workshops. As of December 2018, there are 27 APs, with the aim for 30 on an ongoing basis, which would involve approximately 350 deer farms. This paper describes the history, functioning and measured outcomes of APs within the New Zealand deer industry. Keywords: Deer Industry New Zealand; Passion2Profit; deer-farming practice change}, issn = {1176-5283}, author = {Moffat I and Asher GW} } @article {3672, title = {Effect of breed and paddock activity on bone mass and strength in three beef cattle breeds}, journal = {New Zealand Journal of Animal Science and Production}, volume = {80}, year = {2020}, month = {09/2020}, pages = {29-33}, address = {Online}, abstract = {There are obvious phenotypic differences among beef cattle breeds, but, to date, there are limited data on the effect of breed and pasture-based management systems on the bone mass and strength of the distal limb bone (metacarpals). The left 3rd/4th metacarpal bones were collected from a cohort of Angus (AA) (n= 17), Angus {\texttimes} Friesian (AF) (n=13), and Angus {\texttimes} Jersey (AJ) (n=13) cows aged nine years at slaughter. Prior to slaughter the cohort had been intensively monitored as part of longevity- and GPS-based paddock-activity trials. Measures of metacarpal bone mass and strength were assessed using peripheral quantitative computed tomography (pQCT) scanning at the mid-diaphysis after slaughter. Locomotion parameters, based on GPS data when grazing, were collected when four and five years old. The AA and AF cows had significantly greater slaughter weight than AJ (598{\textpm}14 vs 586{\textpm}18 vs 514{\textpm}17 kg, P<0.01 respectively). AA cows had lower wither height than AF and AJ (1288{\textpm}6 vs 1311{\textpm}8 vs 1269{\textpm}7 mm, P<0.01) and shorter metacarpal bone length (198{\textpm}2, vs 207{\textpm}2 vs 210{\textpm}2 mm, P<0.05). At the mid-diaphyseal site, AF and AJ cows had greater bone mineral density (BMD)v than did AA cows (977{\textpm}8 vs 1018{\textpm}9 vs 1019{\textpm}9 mg/cm3, respectively, P<0.001), but had less cross-sectional area (882{\textpm}16 vs 816{\textpm}18 vs 731{\textpm}18 g/cm3, P<0.05 respectively). Across all breeds, there was a negative relationship of slaughter weight with BMDv. No significant relationships were found between distance walked on moderate and steep terrain (GPS data) and the pQCT measures. Breed influenced the size and structure of the metacarpal bone, which altered the material properties (pQCT) measured. The limited amount of high-strain-rate exercise in these cattle may explain the lack of association between locomotion data and measures of bone mass and strength. Keywords: bovine; bone; GPS; locomotion; beef}, issn = {1176-5283}, author = {Bijen L and Gibson MJ and Back PJ and Hickson RE and van Knegsel A and Rogers CW} } @article {3672, title = {Effect of simulated spot-sampling duration and timing on the precision of methane estimation from cattle using respiration chambers}, journal = {New Zealand Journal of Animal Science and Production}, volume = {80}, year = {2020}, month = {09/2020}, pages = {65-69}, address = {Online}, abstract = {The objective of the current study was to determine the precision of CH4 emission estimates from simulated spot-samples of variable time length (0.25 to 3.0 h) and over time compared to 24-h measured CH4 emissions, both based on respiration chamber data of the same day within cattle. Respiration chamber methane data, recorded approximately every 3 min, from two experiments were used, each with 12 growing beef cattle measured over two or three consecutive days. The ~3 min CH4 emissions during 24 h per animal per day were averaged in time intervals (bins; i.e. simulated spot-sample duration) of 0.25, 0.5, 1.0 and 3.0 h (expressed as g/d) from morning and from afternoon feeding. Precision of each time bin was evaluated by determining between-animal coefficient of variation (CV) and Pearson correlation (r) with 24-h measured emissions. In general, the average CV increased and the CV became more variable over time when the bin duration decreased from 3 h to 0.25 h. The correlation was low (r of approximately 0.1 to 0.5) in the first 0.5 to 2 h after the start of a feeding, after which the correlations increased (r of approximately 0.5 to 0.9) and remained relatively constant up to about 8 h after feeding. The overall trends observed suggest that the precision of a CH4 measurement improved with increasing simulated spot-sample (bin) duration from 0.25 to 3 h and the best time to take a spot-sample (based on any of the bin durations) would be between approximately 1 to 6-8 h after feeding. However, the best timing to perform spot-sampling was not fully consistent between the experiments and between emissions after morning and afternoon feeding, which warrants further investigation. Keywords: Spot-sampling; enteric methane; precision; time bin; variation}, issn = {1176-5283}, author = {Biswas AA and Joner A} } @article {3672, title = {Evaluating anti-CarLA salivary IgA response in a deer progeny test}, journal = {New Zealand Journal of Animal Science and Production}, volume = {80}, year = {2020}, month = {09/2020}, pages = {156-160}, address = {Online}, abstract = {Farmed red deer (Cervus elaphus spp) are susceptible to infection by nematode parasites. A salivary antibody (IgA) that is naturally produced in response to exposure to a nematode parasite carbohydrate larval surface antigen (CarLA) can provide a protection against gastro-intestinal nematodes in sheep and rising-yearling farmed red deer. The concentrations of this CarLA-IgA were measured in saliva samples collected at 6 and 10 months of age, in 1531 rising-yearling progeny of 36 sires across three farms during a three-year progeny test. The CarLA-IgA concentrations differed across sires, farms and years, with 6-month levels being much lower than 10-month levels. Heritability estimates were low (h2=0.10) for 6 months, but moderate and significant (h2=0.37, P<0.05) for 10 months. These two traits were highly genetically correlated (rg=0.86) and moderately phenotypically correlated (rp=0.27). There were low (rp 0.08-0.13) but significant (P<0.05) favourable phenotypic correlations with spring and pre-slaughter live weight, and with growth rate from 3 to 10 months of age and 6 to 10 months of age. Sire variation and heritability of 10-month response indicates that it may have utility as a selection criterion for improved ability of farmed deer to cope with nematode challenge. Keywords: red deer; nematode parasite; carbohydrate larval antigen; immune; Cervus elaphus}, issn = {1176-5283}, author = {Ward JF and Wheeler M and Shaw RJ and Asher GW} } @article {3672, title = {Factors affecting early concentrate uptake by calves}, journal = {New Zealand Journal of Animal Science and Production}, volume = {80}, year = {2020}, month = {09/2020}, pages = {95-100}, address = {Online}, abstract = {Early solid food intake is key to a successful early rumen development system. In NZ, specialist bull-calf rearers tend to feed four-day-old calves restricted milk, ad lib pellets and wean early (5 to 6 weeks). A range of experiments examined the effect of protein \%, feed form and the effect of changing protein source in older calves. There was no difference between 16\% and 20\% protein pellets in the first three weeks but between weeks three and six, feed intakes and liveweight gains were higher on 20\% protein pellets (P<0.05). Weaning live weights were higher on a customised pellet (51.5\% maize, 20.0\% peas, 20.0\% soy bean extract 48, 5\% molasses, 1.5\% limestone, 1.0\% soybean oil, 0.8\% salt, calf vitamin mineral premix (0.01\%), Bovatec (0.006\%) and Rumasweet palatant (0.00002\%)) than on a commercial pellet (68.9 vs 64.8 kg, P<0.05). Feeding the customised formulation either in roller-milled, hammer-milled or pelleted form did not affect feed intake or liveweight gain. In weaned calves welladjusted to consuming concentrates, substituting a commercial meal with palm kernel significantly reduced feed intake when fed at 60\% of the ration whilst copra meal substitution significantly reduced intake at 40\% in calves accustomed to eating pellets. Pellet composition had a greater impact on feed intakes and growth rate than did the form in which the feed was offered. Keywords: calf; copra meal; palm kernel; protein content; artificially reared}, issn = {1176-5283}, author = {Muir PD and Thomson BC and Smith NB} } @article {3672, title = {Genetic evaluation for farm profitability in a commercial grazing dairy herd of Uruguay}, journal = {New Zealand Journal of Animal Science and Production}, volume = {80}, year = {2020}, month = {09/2020}, pages = {55-59}, address = {Online}, abstract = {The objective of this study was to develop a genetic evaluation model for farm profitability in a seasonally calving pasture-based dairy herd in Uruguay using crossbred cows. Total lactation yields of milk (MILK), fat (FAT) and protein (PROT) were calculated for each cow-lactation using the test-interval method. Somatic cell score (SCS) was calculated as the average of log2 (somatic cell count) for each cow-lactation. Mating records were used to calculate days from start of mating to conception (SMCO). Cow live weight (LWT) was recorded once per lactation. Cows were scored annually for udder depth (UD), udder support (US), front and rear teat placement (FT and RT). In total there were 4,081 lactations from 2,371 cows recorded from 2015 to 2017. The cows were the progeny of 97 sires. Breeding values (BV) for MILK, FAT, PROT, LWT, SMCO, SCS, UD, US, FT and RT were estimated with a multi-trait repeatability animal model that included the fixed effects of contemporary group (year-lactation number) and deviation from median calving date, and the random effects of animal, cow permanent and residual error. Estimates of BVs for these traits were combined in a selection index to rank cows for farm profitability. The index was calculated as I= {\textendash}0.074{\texttimes}BVMILK +2.13{\texttimes}BVFAT +7.25{\texttimes}BVPROT {\textendash}1.48{\texttimes}BVLWT {\textendash}3.60{\texttimes}BVSMCO {\textendash}36.84{\texttimes}BVSCS +30.86{\texttimes}BVUD +19.67{\texttimes}BVUS +21.10{\texttimes}BVFT +20.07{\texttimes}BVRT. The index has been used to select the best cows as mothers of future replacements, cull the cows with the lowest selection index value, and for the selection and culling of heifer replacements. Keywords: genetic evaluation; genetic parameters; selection index; Uruguay}, issn = {1176-5283}, author = {Laborde D and Lopez-villalobos N} } @article {3672, title = {Genetic parameters, breed and heterosis effects for conformation scores in cows milked once a day}, journal = {New Zealand Journal of Animal Science and Production}, volume = {80}, year = {2020}, month = {09/2020}, pages = {51-54}, address = {Online}, abstract = {The use of conformation traits to aid selection for functional cows becomes more important as once-a-day (OAD) milking for whole or part season becomes more common. In 2013, Massey University Dairy 1 farm transitioned their mixed-breed herd milked twice-a-day (TAD) to an OAD spring-calving system. All cows on the farm were scored for 14 inspector-scored type traits and four farmer-scored traits, for a total of 1,617 lactation records over seven seasons (2013-2019, 168 to 258 cows per year). Genetic parameters, breed and heterosis effects were obtained from an animal model that included the fixed effects of year of scoring and cow age at scoring, and the covariates of proportion Holstein-Friesian, heterosis between Holstein-Friesian and Jersey, and the random effects of permanent environment of cow and random additive genetic effect of animal. Stature and live weight were found to have the greatest heritability estimates (0.46 and 0.41 respectively), while leg angle and body condition score had the lowest (0.03 and 0.04 respectively). Breed had a significant effect on all type scores, with heterosis also having significant effects; this is an important consideration with the increasing importance of type scores for cows in OAD milking systems. Jersey cows had greater front udder and udder support scores than did Holstein-Friesians (P<0.05), while Holstein-Friesians had greater stature and liveweight scores (P<0.05). From this study, genetic selection for improved udder conformation would see beneficial gains over time, whilst body condition score is heritable, would not be similarly improved. Keywords: Traits other than production; once-a-day milking; genetic parameters}, issn = {1176-5283}, author = {Sneddon NW and Donaghy DJ and Lopez-villalobos N} } @article {3672, title = {Impact of the proximity of the water source on survival and growth of triplet lambs {\textendash} a case study}, journal = {New Zealand Journal of Animal Science and Production}, volume = {80}, year = {2020}, month = {09/2020}, pages = {45-50}, address = {Online}, abstract = {The objective of this study was to evaluate whether the provision of greater access to watering sites two weeks prior to lambing and at least one week after lambing impacts lamb survival and growth to weaning, using triplets as a model. Triplet-bearing ewes (n=206, 116-131 days gestation) were randomly allocated to either the control (one water trough/paddock) or treatment group (2-3 water troughs/paddock) balanced for ewe live weight, body condition score and stage of gestation, at a stocking density of 8.6-9.1 ewes/ha with three replicated paddocks/treatment. Lamb survival was determined via DNA parentage and lamb growth recorded at docking, weaning and at six months of age. Lamb survival (60 vs 62\%, P=0.690) and lamb growth (P=0.452) did not differ between the treatment and control groups. The key finding of this study was that increasing the availability of a water supply to triplet-bearing ewes in late pregnancy and early lactation did not influence lamb survival or growth. Keywords: sheep; triplets; water; lamb survival}, issn = {1176-5283}, author = {McCoard S and Wing J and Smith T and Hea S-Y} } @article {3672, title = {Impact of trait genetic gains on methane emissions from NZ beef and dairy farms}, journal = {New Zealand Journal of Animal Science and Production}, volume = {80}, year = {2020}, month = {09/2020}, pages = {76-79}, address = {Online}, abstract = {The objective of this study was to provide estimates of the impact of trait genetic gains on methane emissions from NZ dairy and beef farms. The effect of each trait on gross emissions (GE) and emissions intensity (EI) was modelled by estimating effects of trait changes on per-animal feed consumption and the associated methane production, per-animal production and numbers of animals in the system. In dairy, the annual gross emissions per breeding cow associated with genetic change were estimated to increase for all traits except Residual Survival and Fertility. Conversely, emission intensity values were estimated to decrease for Milk Fat, Milk Protein, Milk Solids, Residual Survival, Fertility and Body-condition Score (BCS) as genetic merit improves. In beef production, increases in genetic merit for cow mature weight, cow BCS, cow calving ease and heifer pregnancy were estimated to increase the annual gross emissions per breeding cow. Conversely, an increase in merit associated with stayability and gestation length reduced annual gross emissions per breeding cow. The effect of increasing carcase weight on gross emissions depended on whether the faster growth performance was used to slaughter the animal earlier, or to take the animal through to heavier finishing weights. Keywords: methane; emissions intensity; gross emissions; dairy; beef}, issn = {1176-5283}, author = {Proctor LE and Archer JA and Sise JA and Zhang X and Crowley JJ and Amer PR} } @article {3672, title = {Implications of using an extended lactation to change from a spring-calving to an autumncalving farm system in South Taranaki}, journal = {New Zealand Journal of Animal Science and Production}, volume = {80}, year = {2020}, month = {09/2020}, pages = {143-149}, address = {Online}, abstract = {Recent changes to pasture-supply curves in South Taranaki, and the availability of winter milk premiums have increased farmer interest in changing from a spring-calving to an autumn-calving farm system. One approach to changing the season of calving from spring to autumn is to extend the calving interval (CI) by delaying the mating period by ~8 months, so that they next calve in autumn and undertake an extended lactation [>305 days in milk (DIM)]. A large-scale farmlet experiment was established in South Taranaki to investigate the production and reproduction responses of cows using this approach. In June 2017, 602 springcalving cows were allocated to two farmlets. In one farmlet (SPR) 301 cows were mated in October to maintain a 12-month CI spring-calving pattern. In the other farmlet (AUT, n=301 cows), mating was delayed for eight months, and cows underwent an extended lactation (mean DIM, 488; max DIM, 577) to calve next in autumn 2019. The experiment analysed two lactations for the AUT farmlet and two and a half lactations for the SPR farmlet. Across the total experimental period, milksolids (MS) production was similar between farmlets (1,194 vs. 1,174 kg MS/cow), however, cows in the AUT farmlet were fed more supplementary feed [2,371 vs. 1,951 kg dry matter (DM)/cow]. The extended lactation changed the relationship between feed supply and herd demand, which led to excessive BCS gain and ryegrass staggers for AUT farmlet cows. Further research is required to examine grazing management during extended lactations and to assess the economic implications of this approach. Keywords: autumn calving; spring calving; extended lactation}, issn = {1176-5283}, author = {Jarman JWM and Kay JK and Neal M and Donaghy DJ and Tozer P} } @article {3672, title = {Koura: a novel diversified product for a changing primary sector}, journal = {New Zealand Journal of Animal Science and Production}, volume = {80}, year = {2020}, month = {09/2020}, pages = {80-83}, chapter = {80}, address = {Online}, abstract = {Primary sector industries in New Zealand are under increasing pressure from community to produce products with lower environmental impacts, to both air and water. Contrasting these pressures is a growing world-wide demand for protein, which historically required increased intensification and associated negative environmental impacts. One area promoted for environmental mitigation is the fencing of riparian zones along waterways. The practicalities of this can create operational issues and large areas of land can essentially become non-productive for livestock and timber production. Novel solutions could provide commercial benefit from within these riparian zones. Ernslaw One Ltd. have created approximately 20 hectares of ponds along riparian edges in their Otago and Southland forests. These ponds are used to farm freshwater crayfish or koura (Paranephrops zealandicus) in areas that would otherwise be unproductive as production forest can no longer be grown there for environmental reasons. Customers are increasingly looking for niche foods with unique provenance such as koura. Currently the koura industry is in its infancy but there are many groups with licence applications underway. Utilisation of these landscape units add scale and speed towards development of a viable industry with domestic and export potential. High-value novel products such as koura demonstrate that revenue can be obtained with little environmental impact. Keywords: koura; aquaculture; diversification; sustainable; freshwater}, issn = {1176-5283}, author = {JW Hollows} } @article {3672, title = {Liveweight gain and urinary nitrogen excretion of lambs grazing diverse (plantain, Italian ryegrass and red clover) or ryegrass-white clover pasture in autumn}, journal = {New Zealand Journal of Animal Science and Production}, volume = {80}, year = {2020}, month = {09/2020}, pages = {70-75}, address = {Online}, abstract = {The objective of this study was to investigate the effect of grazing a diverse pasture of plantain, Italian ryegrass, and red clover versus a ryegrass-white clover pasture on the liveweight gain (LWG) and urinary nitrogen (N) excretion of ram lambs over an 82- day experimental period in autumn. Eighty Coopworth ram lambs (8 months old) were allocated to two replicates of two pasture treatments (n = 20), a diverse pasture containing plantain, Italian ryegrass, and red clover (Diverse) and conventional ryegrass-white clover pasture (RGWC). Unfasted live weight (LWT) of lambs was recorded on seven occasions during the autumn experimental period. Apparent dry matter intake (DMI) was estimated as the difference between pre- and post-grazing herbage mass plus daily herbage growth. On two occasions, urine and blood samples were collected from each lamb to determine concentration of urinary N and plasma urea N (PUN). Liveweight gain (P=0.008) and feed conversion efficiency (P=0.022) were greater in Diverse than RGWC treatment (240 vs 160 g/day and 111 vs 86 g LWT per kg DMI, respectively). Urinary N and PUN concentration were similar between treatments; however, when urinary N excretion (g/d) was estimated as a function of PUN, lambs grazing Diverse pasture excreted less (P=0.003) urinary N per 100 g LWG than those grazing RGWC pasture. The proportion of N intake retained in LWG was greater (P=0.008) for lambs grazing Diverse (11.0\%) than those grazing RGWC (9.0\%). The results indicate that there is a potential to achieve target LWT of lambs in a shorter time and with less N loss to the environment by using a diverse mix containing plantain, Italian ryegrass and red clover in comparison to ryegrass-white clover mix in autumn. Keywords: Growing lambs; liveweight gain; urinary nitrogen; diverse pasture; ryegrass}, issn = {1176-5283}, author = {Al-marashdeh O and Cook GA and Anderson FC and Meyer JPH and Logan CM and Edwards GR and Maxwell TMR} } @article {3672, title = {The management of Standardbred breeding stock on commercial properties}, journal = {New Zealand Journal of Animal Science and Production}, volume = {80}, year = {2020}, month = {09/2020}, pages = {84-89}, address = {Online}, abstract = {This paper describes the on-farm pasture management of Standardbred broodmares on commercial breeding farms in New Zealand using data collected from three studies. The pasture on offer was typically ryegrass (70\% (IQR 50-70), clover (15\% (IQR 15-22), and fescue (12\% IQR 6-22). Other species present included cocksfoot and plantain (10\% on one farm). Weed content was low at 5\% (IQR 4-8). During winter, on two farms mares were break-fed on crops of kale, standing oats and Italian ryegrass. Through the year there was limited variation in the nutritive composition of the pasture with a DM of 17{\textpm}0.3\%, ME of 11{\textpm}0.1 MJ/kg DM and crude protein of 23{\textpm}0.5\%. Horses were managed using a semi-set-stocked pattern (1.7 mares/ha; 2.6 weanlings/ha). Pasture DM on offer for mares ranged from 1700-2500 kg DM/ha and 2500-3000 kg DM/ha for weanlings, which were also offered ~1.5 kg/ day (as fed) of pre-mixed concentrates. To manage pasture quality and minimise the establishment of lawns and roughs, paddocks on all farms were harrowed and cross-grazed with sheep or cattle. The management system described, while similar to that of Thoroughbreds, differs with the offering of crops to mares during winter and a higher BCS of mares. Keywords: horse; pasture; Standardbred; management; mare}, issn = {1176-5283}, author = {Rogers CW and Herbst A and Langhans K and Stone R and Hirst R and Gee EK and Back PJ} } @article {3672, title = {Milk composition and productive and reproductive performance of cows from A1 and A2 β-casein variants, milked once or twice a day}, journal = {New Zealand Journal of Animal Science and Production}, volume = {80}, year = {2020}, month = {09/2020}, pages = {137-142}, address = {Online}, abstract = {Protein is an important component of milk and it plays an essential role in all living organisms. β-casomorphins-7 (BCM-7) is derived from A1 β-casein and has been implicated in some human health issues. This A1 β-casein is produced by cows with the A1A1 or A1A2 genotype, whilst cows with the A2A2 genotype produce A2 β-casein, which has not been implicated in the same human health issues. Given the potential importance of A2 milk for public health and its apparent commercial potential, selection based on the A2 genotype and its impact on production and reproduction traits should be investigated. The objective of the current study was to compare the productive and reproductive performance of dairy cows based on A2 genotype in two different dairy farms. From July 2017 to May 2018, 206 cows (including 122 A2A2 genotype; {\textquotedblleft}A2 cows{\textquotedblright}) were milked once a day at Dairy 1 and 451 cows (including 217 A2 cows) were milked twice a day at Dairy 4. Records of lactation yields of milk, fat and protein, fat percentage, protein percentage, days from start of mating to conception, pregnancy rate to first service, the submission rate at 21 days and the pregnancy rate at 21 and 42 days (PR42) after the start of mating from 642 cows in two herds were analysed. The effects of A2 genotype on production and reproduction traits were not significant. The interaction between farm and β-casein genotype was significant for PR42 (P<0.05) but not for any other traits. The interactions between parity number and genotype were not significant for any of the traits. The results indicated that cows of different β-casein genotypes have similar production and reproductive performance. Keywords: β-casein genotype; A2 milk; protein percentage; pregnancy rate at 42 days}, issn = {1176-5283}, author = {Lu Y and Hickson RE and Gedye K and Correa-Luna M and Donaghy DJ and Lopez-villalobos N} } @article {3672, title = {Miniature horses in New Zealand: demographics and feeding management}, journal = {New Zealand Journal of Animal Science and Production}, volume = {80}, year = {2020}, month = {09/2020}, pages = {1-7}, type = {1-7}, address = {Online}, abstract = {An online survey on demographics and feeding management of Miniature horses in New Zealand was conducted using the Qualtrics Survey Software. There were 232 valid responses from respondents who kept 1183 Miniature horses, representing ~ 1/3rd of the New Zealand Miniature horse population. Miniature horses were kept for leisure and companionship (56\%), competition (35\%) and for breeding (7\%). The majority (79\%) of Miniature horses were kept at pasture on low (< 1000 kg DM/ha) to moderate (~ 2000 kg DM/ha) pasture masses across seasons. Pasture access was more commonly restricted by respondents during spring (60\%), summer (60\%), and autumn (55\%) than in winter (43\%). Most respondents (87\%) practiced pasture-restriction strategies such as strip grazing, use of a paddock with little grass, and stabling/yarding. Respondents indicated the mode daily number of hours of stabling was 7-12 hours (n=57/195, 29\%). The median stocking density was 10 horses/ha, (~1100 kg live weight/ha). The stocking density appeared high, however, on a live weight basis, it was comparable to the reported values in other classes of equine livestock.}, issn = {1176-5283}, author = {Goh SY and Gee EK and Thomas DG and Back PJ and Rogers CW} } @article {3672, title = {A model to assess the impact of potential genetic selection of dairy cows for volume per urination and total urine volume per day on nitrogen leaching}, journal = {New Zealand Journal of Animal Science and Production}, volume = {80}, year = {2020}, month = {09/2020}, pages = {60-64}, address = {Online}, abstract = {The purpose of this paper is to assess the impacts of changes in herd average urine genetic traits on nitrogen (N) leaching per hectare per year. Two potential urine traits being considered for genetic selection are total volume of urine per cow per day (at constant urinary N output), and average volume per urination (at a constant daily urinary volume and N output). To understand the potential reduction in N leaching that would arise if these traits could be changed using genetic selection, a model of urine patches was developed to derive the necessary relationships between urine genetic traits, patch characteristics, and N leaching. To simulate the effect on N leaching of genetic selection the mean for each urine trait was then changed from base model values by {\textpm}10\%. Increasing total urine volume per cow per day by 10\% was more effective (4.5\% less N leaching) than decreasing volume per urination by 10\% (2.9\% less N leaching). Also, selection for urine traits at higher stocking rates (four cows/ha) and higher N intake (650 g/N/day) had a lower impact on N leaching compared with lower stocking rates (two cows/ha) and lower N intakes (450 g N/day). This study showed that genetic selection for urine traits could have a positive, but limited, impact on N leaching and would be a useful tool for New Zealand dairy farmers. Keywords: Urine traits; urine patches; nitrate leaching}, issn = {1176-5283}, author = {Kennett JM and Romera A and Beukes P and Amer P} } @article {3672, title = {Persistency and lactation curves modelled using nonlinear random regression in dairy cows milked once a day}, journal = {New Zealand Journal of Animal Science and Production}, volume = {80}, year = {2020}, month = {09/2020}, pages = {131-136}, address = {Online}, abstract = {Modelling lactation curves of dairy cows is important for improved feed management and breeding decisions. The objectives of this study were to compare measures of lactation persistency obtained from the modelling of lactation curves for daily yields of milk, fat and protein using a nonlinear random regression model in dairy cows milked once a day under grazing conditions. A total of 1,955 monthly herd-test records of milk, fat and protein from 55 Holstein-Friesian (F), 64 Jersey (J), and 123 F{\texttimes}J crossbreds of different lactations were used to obtain lactation curves for each cow using a random regression model with the Wood function. Three measures of persistency were calculated based on ratios of yields and compared with persistency calculated based on parameters of the Wood function. Jersey cows in lactation 3 had the greatest persistency for all persistency measures. In first-lactation cows, there were no significant breed differences in persistency. Persistency measures were strongly correlated with each other (r>=0.97; P<0.001). The conclusion from this study is that parameters of the lactation curve (peak yield, day of peak and persistency) can be precisely estimated using the random regression model with the Wood function. Keywords: modelling; lactation curve; persistency; once-a-day milking}, issn = {1176-5283}, author = {Jiang H and Hickson RE and Woods OT and Morandeau M and Burke JL and Correa-Luna M and Donaghy DJ and Lopez-villalobos N} } @article {3672, title = {Predicting internal adipose from selected computed tomography images in sheep}, journal = {New Zealand Journal of Animal Science and Production}, volume = {80}, year = {2020}, month = {09/2020}, pages = {113-116}, address = {Online}, abstract = {Dairy cattle preferentially lay down internal (INT) (e.g., kidney) adipose relative to sub-cutaneous adipose (SCF) tissue, but this pattern is the opposite in beef cattle, which preferentially deposit adipose subcutaneously. It is proposed that these differential patterns of fat distribution evolved to match the different production drivers of these breeds. As the New Zealand sheep industry has become more diverse in terms of breeds and production systems, the role that differential adipose distribution could play in supporting different production systems is of interest. The potential to use commercially obtained Computed Tomography (CT) images (i.e., six images, selected to predict carcass attributes in the live animal), to additionally predict INTF in addition to carcass fatness, was investigated using a full set (i.e., 30-32) of CT images available on 50 maternal ewe lambs. The R2 between the fulland sub-set of images for absolute amounts ranged from 0.25 for bone to 0.92 for SCF, with INTF 0.77 (P<0.001). When adjusted for total weight, correlations were slightly reduced, but still supported the ability of the analysis of the six images to accurately identify animals with differential fat distribution. Future work will include analysis of a further 550 animals from the same data set to determine the genetic correlation between the full and subset of images. If successful, adipose distribution can be predicted from existing and future commercial CT data sets and used to investigate its genetic and phenotypic relationship with production traits. Keywords: internal adipose; subcutaneous adipose; computed tomography}, issn = {1176-5283}, author = {PL Johnson and Juengel JL and Bain WE} } @article {3672, title = {Relationship between body condition score and pregnancy rates following artificial insemination and subsequent natural mating in beef cows on commercial farms in New Zealand}, journal = {New Zealand Journal of Animal Science and Production}, volume = {80}, year = {2020}, month = {09/2020}, pages = {14-20}, address = {Online}, abstract = {Body condition scoring is an efficient on-farm visual-assessment tool used to describe the energy reserves of animals. Cow body condition score (BCS) at crucial time points throughout the year is likely to influence reproductive performance. The aim of this experiment was to examine the influence of BCS before calving, before mating and at weaning on reproductive performance of mature beef cows. Percentage of cows conceiving to a single artificial insemination (AI) at a synchronised oestrus and pregnancy rate after 49 days of mating were determined for a total of 2,683 individual cows. Cows with a greater than average BCS had greater pregnancy rate to AI than did those with low BCS (P<0.001). The percentage of animals conceiving to AI was on average 54.8\% but was lower at 42.5\% for pre-mating BCS 4.5 or greater at 64.5\% for BCS 9.0 (P<0.001). Cows had greater overall pregnancy rate after 49 days of mating with greater BCS; ranging from 88.3\%, 75.7\% and 79.7\% for BCS 4.5 before calving, before mating and at weaning, respectively, to 93.5\%, 93.3\% and 93.3\% for BCS 8.0 at the same time points. Increasing BCS up to 7 is likely to improve overall pregnancy rate, and most benefit tends to come from improving BCS in lower-conditioned cows to achieve high pregnancy results. Keywords: beef cows; BCS; reproductive performance; pregnancy rate; artificial insemination}, issn = {1176-5283}, author = {Weik F and Archer JA and Morris ST and Garrick DJ and Hickson RE} } @article {3672, title = {Relationship between gamma-glutamyl transferase (GGT) concentrations and lying behaviour in dairy cattle}, journal = {New Zealand Journal of Animal Science and Production}, volume = {80}, year = {2020}, month = {09/2020}, pages = {24-28}, address = {Online}, abstract = {Facial eczema (FE) in livestock results in liver damage, impaired production and welfare, and is a significant problem in New Zealand. The pathology of this disease has been described in sheep and cattle, however, few studies have investigated the behavioural response to FE and whether behaviour can be used as an indicator of FE. Therefore, the aim of this study was to evaluate lying behaviour of dairy cattle with FE. Six farms located in the North Island of New Zealand with confirmed cases of FE were selected (n=391 lactating cows). Blood samples were collected to analyse gamma-glutamyl transferase (GGT) concentrations and three days of continuous lying behaviour were recorded using accelerometers. There was no correlation between GGT concentrations and either lying times (r2=0.0008) or lying bout frequency (r2=0.0008) when all animals were included in the analysis. In addition, lying times (means{\textpm}SEM: Low: 9{\textpm}0.1 h/d, High: 9{\textpm}0.1 h/d; P=0.347) and lying bout frequency (means{\textpm}SEM: Low: 8{\textpm}0.2 no. bouts/d, High: 8{\textpm}0.2 no. bouts/d; P=0.149) did not differ between pair-matched cows with Low (<= 89 IU/L) or High (>= 123 IU/L) GGT concentrations. Therefore, it does not appear as though lying behaviour, measured using accelerometers, is associated with GGT levels in dairy cattle. Keywords: facial eczema; gamma-glutamyl transferase; lying behaviour}, issn = {1176-5283}, author = {Sutherland M and Huddart F and Lowe G and Cox N and Cuttance E and Sch{\"u}tz K} } @article {3672, title = {REVIEW: Critiquing the relationship between body condition and animal welfare}, journal = {New Zealand Journal of Animal Science and Production}, volume = {80}, year = {2020}, month = {09/2020}, pages = {39-44}, address = {Online}, abstract = {Body condition has long been used when assessing animal health and productivity, both important indicators of animal welfare; however, assessments of animal welfare must also consider the extent to which animals{\textquoteright} emotional needs are met. New Zealand{\textquoteright}s codes of welfare focus on using body condition score as a measure of emaciation, requiring action to be taken at very low scores and generally recommending higher scores. In anticipation of future code reviews, the National Animal Welfare Advisory Committee is exploring our understanding of body condition as a measure of welfare, with a view to incorporating standards that also take account of animals{\textquoteright} affective or emotional states. Most of the scientific literature appears related to optimising animal health and production and body condition score is a good indicator of an animal{\textquoteright}s energy reserves. While affective or emotional state may be more difficult to assess, thinner animals seem more motivated to feed as they spend more time foraging and consume more feed than {\textquoteleft}better{\textquoteright} conditioned animals. In addition, animals losing condition were more interested, anxious or excited, suggesting higher feeding motivation and possibly hunger. A more nuanced understanding is needed that considers the circumstances of the animal; what individual animals are feeling; and that body condition per se may not necessarily reflect hunger. In addition, the stage at which compromises to body condition are deemed unreasonable or unnecessary, and the reserves required in extensive environments, suggest more complex research, regulatory and non-regulatory understandings and interventions will be required. Keywords: body condition; survival; production; health; behaviour; feelings; animal-welfare standards}, issn = {1176-5283}, author = {Fisher MW and Sch{\"u}tz KE and Verkerk} } @article {3672, title = {Seasonal effects of two forage-based nutrition regimens on intake and average daily gain of three genotypes of young red deer (Cervus elaphus)}, journal = {New Zealand Journal of Animal Science and Production}, volume = {80}, year = {2020}, month = {09/2020}, pages = {150-155}, address = {Online}, abstract = {The red deer genotypes currently being farmed in New Zealand have different forage-use habits and exhibit different growth profiles in different seasons. Three genotypes (NZ red, eastern European and elk-cross) were subjected to low and high nutritional regimens during autumn, winter and spring. Few differences among genotypes were found in autumn, but in winter the elk-cross genotype grew faster than did the NZ red and eastern European genotypes. NZ red deer consumed approximately 9\% of their diet as hay in both autumn and winter, while eastern European and elk-cross deer had much higher intakes of hay (up to 44\%). Divergence in response to the high- or low-nutrition regimens imposed developed in winter. Liveweight gain averaged 84 g/d on the low nutrition regimen and ranged from 132 to 199 g/d for NZ red and elk-cross genotypes respectively on the high-nutrition regimen. Eastern European deer were immediate. In spring as the NZ red genotype did not respond to increasing feed availability, while the eastern European and elk-cross deer increased growth rate by approximately 50 g/d and 100 g/d, respectively, in response to increased feed availability. This was matched by increases in forage and metabolisable energy intake. Understanding these interactions provides information that will enable feeding systems to be tailored to deer genotype to improve on-farm resource-use efficiency. Keywords: diet selection; energy; forage intake; genotype; liveweight gain; red deer; seasonality.}, issn = {1176-5283}, author = {Stevens DR and Corson ID} } @article {3672, title = {A survey of fodder beet use and feeding practices on dairy farms in Canterbury, Otago and Southland}, journal = {New Zealand Journal of Animal Science and Production}, volume = {80}, year = {2020}, month = {09/2020}, pages = {101-106}, address = {Online}, abstract = {High yields, consistent quality and emerging environmental benefits make fodder beet (FB) an important feed in South Island dairy systems. However, these benefits may be negated by animal-health issues associated with some FB-feeding regimes. To quantify the range and prevalence of feeding regimes, a telephone survey focussing on practices in 2018 was conducted in Canterbury, Otago and Southland. Of the farmers surveyed, 69\% fed FB, 24\% had never fed FB and 8\% of farmers had stopped feeding FB. The most frequently cited reasons for having stopped feeding FB were animal-health issues, cost and management challenges. Most (82\%) respondents feeding FB determined allocation by yield and break area. Almost all farmers (98\%) transitioned cattle on to FB, over an average of three weeks. Of those that fed FB to non-lactating cows in winter, the mean allocation was 10.3 kg DM/cow/day (66\% of the diet), and 12\% fed FB ad libitum. A greater proportion of herds fed FB (41\% of herds) reported metabolic issues (>5\% of the herd affected) compared with herds not fed FB (23\%). This survey is valuable to inform future research and reinforces the need to continue investigating animal-health issues associated with FB-feeding, with an emphasis on metabolic issues. Keywords: fodder beet; winter crop; animal health}, issn = {1176-5283}, author = {Edwards JP and Dalley DE and Pinxterhuis JB and Woods RR} } @article {3672, title = {Technical note: A comparison of editing criteria for lying-behaviour data derived from three-dimensional accelerometer devices on grazing dairy cows}, journal = {New Zealand Journal of Animal Science and Production}, volume = {80}, year = {2020}, month = {09/2020}, pages = {8-13}, address = {Online}, abstract = {Shorter, more-frequent lying bouts (LB) could be used to predict calving and as an indicator of animal discomfort and ill-health. In this technical study, we reviewed the literature to describe criteria for removing false short LB, caused by minor movements, from accelerometer data using IceRobotics technology. Using an existing dataset of grazing cows, we compared unedited with edited accelerometer data after applying three different LB thresholds (LB <33 s, <=2 min, and <4 min were removed) within IceQube and IceTag accelerometers. Daily lying time, LB (no./d) and LB duration were derived from either IceQube or IceTag devices for 146 and 159 multiparous cows, respectively. Very-short LB were more common in IceTag than IceQube data. Applying a shorter LB criterion (<33 s) to the IceQube dataset produced minimal differences between unedited (8.8{\textpm}3.6 no./d; n=64,512 lying records) and edited data (8.3{\textpm}3.4 no./d; n=60,463). In contrast, we observed large differences between unedited (307{\textpm}293 no./d; n=2,305,693) and edited data (8.8{\textpm}4.1 no./d; n=66,139) when a longer LB criterion (<=2 min) was applied to the IceTag dataset. Removing short LB that are unlikely to represent true behaviour will improve the interpretation of lying behaviour data; however, prospective studies are needed to determine the most-suitable LB criterion. Keywords: lying behaviour; grazing cows; accelerometer}, issn = {1176-5283}, author = {Hendriks SJ and Phyn CVC and Turner S-A and Mueller KR and Kuhn-Sherlock B and Donaghy DJ and Huzzey JM and Roche JR} } @article {3672, title = {Trainers perceptions of the impact of different feeding and management practices on racehorses they identified displaying symptoms of recurrent exertional rhabdomyolysis}, journal = {New Zealand Journal of Animal Science and Production}, volume = {80}, year = {2020}, month = {09/2020}, pages = {90-94}, address = {Online}, abstract = {Data on the feeding and management of racehorses and the practices perceived to benefit horses displaying signs of recurrent exertional rhabdomyolysis (RER) were collected via a cross-sectional face-to-face survey of 100 registered Thoroughbred and Standardbred trainers in New Zealand (n=1,771 horses). In addition to quantitative data on feeding practices, qualitative data on trainers{\textquoteright} perceptions and motivations for the different feeding and management practices were also collected. Few trainers recognised that starch in the diet was associated with increased clinical signs of RER (26\% of Standardbred and 13\% of Thoroughbred trainers). One third of trainers (39\% of SB and 34\% of TB) stated that oats contributed to RER. Most trainers with RER horses (96\% TB and 84\% SB) provided a day off (day with no training) to these horses. Half of the trainers with RER horses (SB and TB) decreased concentrate feeds on days off for all horses and few trainers (12.5\% SB and 8\% TB) only decreased concentrate on days off if the horse displayed signs of RER. Most trainers had sought advice about RER management from a veterinarian or feed representative (63\% SB and 78\% TB). However, despite this, many of the responses indicated a lack of clarity on the feed and management factors that contribute to the risk of clinical signs of RER.}, issn = {1176-5283}, author = {Wood LJ and Lancaster BE and Breheny MR and CW Rogers} } @article {3672, title = {Vol 80}, journal = {New Zealand Journal of Animal Science and Production}, volume = {80}, year = {2020}, month = {09/2020}, address = {Online}, issn = {1176-5283} } @article {3672, title = {Association of bacterial contamination of colostrum with passive immunity and growth rates in dairy heifer calves}, journal = {New Zealand Journal of Animal Science and Production}, volume = {79}, year = {2019}, month = {07/2019}, pages = {149-152}, address = {Palmerston North}, abstract = {Failure of passive transfer of immunity in calves is associated with poor-quality colostrum, determined by Immunoglobulin G (IgG) concentration. Another quality problem of colostrum is bacterial contamination, which can impair IgG absorption by the calf. Thirty-five samples from daily pooled first-milking colostrum collected over a period of six weeks were tested for IgG concentration and bacterial contamination. Seventeen of 35 first-milking colostrum samples (49\%) had bacterial counts above a 100,000 CFU/ml threshold. Twenty-nine of the 35 pooled colostrum samples were fed to 63 newborn heifer calves, of which 12 (41\%) had bacterial loads above 100,000 CFU/ml and were fed to 36 calves. Only eight samples (28\%) had Brix values >22\% and five samples (17\%) fed to nine calves met the criteria of low bacterial load and high Brix (>22\%). Twelve of the 63 calves (19\%) had serum IgG concentrations <10 mg/ml so were classified as having failure of passive transfer, of which 10 of these calves were offered colostrum with high bacterial counts. However, there was no association of level of bacterial contamination with subsequent growth. There were no differences in serum IgG concentrations of calves which were fed colostrum that exceeded the quality threshold and those that were not. Calves with greater serum IgG concentrations grew faster (P<0.05). }, issn = {1176-5283}, author = {Back PJ and Hickson RE and Sneddon NW and Coleman LW and Laven RA} } @article {3672, title = {Associations of body condition score and change in body condition score with lamb production in New Zealand Romney ewes}, journal = {New Zealand Journal of Animal Science and Production}, volume = {79}, year = {2019}, month = {07/2019}, pages = {91-94}, address = {Palmerston North}, abstract = {Body condition score (BCS) is an on-farm subjective measurement used to inform feed management decisions in sheep. This study determined the associations of BCS and changes in BCS on production. Ewe BCS was recorded four times annually in a flock of 2534 Romney ewes aged one-five, first bred at eight-months of age. Production was measured as the number of fetuses scanned (NLS), number of lambs weaned (NLW), average weight of lambs weaned (WWT) and total weight of lamb weaned (TLW). Ewe BCS was greatest at lambing and lowest at weaning. At pregnancy scanning (at an average of 75 days of pregnancy), two weeks prior to lambing, and at weaning, BCS >=4.5 was associated with the lowest NLS and NLW, but the greatest WWT. Ewes with a BCS <=2.5 at weaning were associated with the greatest TLW, suggesting these ewes had utilised their stored body fat to achieve high milk yields. Ewes that decreased BCS between lambing and weaning produced greater (P<0.05) TLW compared with ewes which maintained or gained BCS indicating their body reserves were acting as a buffer for milk production. The results of the current study showed that there was an effect of BCS on NLS, NLW, WWT and TLW. The change in BCS from scanning to weaning is an important determinate of NLW, WWT and TLW. A further study with more focus on the change in BCS is, therefore, warranted.}, issn = {1176-5283}, author = {Tait IM and Kenyon PR and Garrick DJ and Lopez-villalobos N and Pleasants AB and Hickson RE} } @article {3672, title = {Barriers to the adoption of animal welfare standards: shelter on pastoral farms}, journal = {New Zealand Journal of Animal Science and Production}, volume = {79}, year = {2019}, month = {07/2019}, pages = {37-42}, address = {Palmerston North}, abstract = {The expectations for and provision of shelter for livestock remains a challenge. To help align expectations and recommendations, research was undertaken to determine the main barriers to the greater adoption of standards. Semi-structured qualitative interviews were undertaken with 24 New Zealand farmers and 22 animal-interest stakeholders. In addition, 700 members of the public were surveyed on-line. Shelter was seen as part of good farming, recognized in productivity and efficiency, and was part of the environmental and market demands. While some farmers considered that their shelter could be better, they had other, more-pressing, priorities. The key barriers included costs, time and resources, impacts on productivity, the provision of information and a lack of enforcement. While the public acknowledged animal welfare as important, including providing livestock with shade, shelter and a comfortable resting place, fewer thought that, in this respect, animals were provided for particularly well. It will be necessary to acknowledge the complexity of the issue borne of different animals, environments and people; and that initiatives may be better managed as part of wider social expectations.}, issn = {1176-5283}, author = {Fisher MW and Stockwell W and Hastings A and Brannigan JIE and Lyons CE and Timmer-Arends P} } @article {3672, title = {BRIEF COMMUNICATION: A case study of the effects of diet and winter management on dairy production, profit and nitrate leaching in Rotorua}, journal = {New Zealand Journal of Animal Science and Production}, volume = {79}, year = {2019}, month = {07/2019}, pages = {71-73}, address = {Palmerston North}, abstract = {Feed and winter management options were modelled for a dairy farm and its adjoining support land in the Lake Rotorua catchment. The dairy farm grew turnips, fodder beet and oats, with non-lactating cows grazing on the dry-stock unit on pasture, kale and fodder beet. Scenarios investigated were: removing crops from the dairy farm whilst either A) reducing stocking rates by 5\%; B) feeding additional palm kernel expeller (PKE); C) replacing crops, PKE and pasture silage with purchased maize grain and maize silage; or D) grazing non-lactating cows on the dairy farm and reducing stocking rates by 17\%. Using a milk price of $6.00/kg MS, D was the only scenario that increased profitability of the dairy farm (7\%). Compared to the base scenario, nitrate leaching on the dairy farm increased for scenario D and decreased for scenarios A, B and C. When including the dry-stock unit, total N leaching was reduced by 5, 0, 13 and 15\%, for A, B, C and D, respectively, compared to the base farm. These results reiterate the importance of investigating the impact of off-farm winter grazing in nitrogen-sensitive catchments.}, issn = {1176-5283}, author = {Burggraaf VT and Rennie GR and Edwards P and Pinxterhuis I} } @article {3672, title = {BRIEF COMMUNICATION: Carcass characteristics and meat quality of early, mid- and late-season commercial lambs}, journal = {New Zealand Journal of Animal Science and Production}, volume = {79}, year = {2019}, month = {07/2019}, pages = {80-83}, address = {Palmerston North}, abstract = {Comparisons were made of carcass and meat quality characteristics of three groups of wether lambs (n=15/group): a composite breed slaughtered at weaning (EARLY), and at 6-8 months of age (MID) and Merino lambs slaughtered at 12 months of age (LATE). Carcass weight and eye muscle area were measured and meat quality was measured on the Longissimus thoracis (loin). All lambs had similar carcass weights (18.7-19.0 kg; P>0.05). Meat from LATE lambs had higher ultimate pH and intramuscular fat \% (P<0.001) than EARLY and MID lambs. Loins from EARLY lambs had lower Chroma (P<0.01), higher eye muscle area (P<0.001) and shear force (P<0.05) and greater percentage of polyunsaturated fatty acids (P<0.001) than loins from MID and LATE lambs. Although statistical differences were observed in meat quality measurements, differences in absolute values suggest that the three production systems resulted in minor variation in meat quality.}, issn = {1176-5283}, author = {Ye Y and Schreurs NM and PL Johnson and Corner-Thomas RA and Agnew MP and Silcock P and Eyres GT and Maclennan G and Realini CE} } @article {3672, title = {BRIEF COMMUNICATION: Comparison of meat quality characteristics of lambs weaned at eight or 14 weeks of age grazing perennial ryegrass-white clover pasture or a plantain-clover mix}, journal = {New Zealand Journal of Animal Science and Production}, volume = {79}, year = {2019}, month = {07/2019}, pages = {159-161}, address = {Palmerston North}, abstract = {This study compared the meat quality of lambs grazing either perennial ryegrass-white clover pasture or a plantain-clover mix (plantain, red clover, and white clover) from eight to 14 weeks of age followed by a six-week finishing period on perennial ryegrass-white clover pasture. Ewes and their lambs were allocated to four treatments: 1) lambs weaned early (eight weeks of age) on a plantain-clover mix (EARLY), 2) lambs with dam grazing a plantain-clover mix (HERB), 3) lambs with dam grazing pasture >1200 kgDM/ha (HIGH), and 4) lambs with dam grazing pasture <1200 kgDM/ha (LOW). Following the treatment period, all lambs weighing a minimum of 35 kg were sent for slaughter and all remaining lambs were managed and finished as one mob on perennial ryegrass-white clover pasture for a further six weeks. Lambs that reached a minimum 35 kg live weight were slaughtered and meat samples from each lamb were analysed for ultimate pH, meat colour (L*, a*, b*), drip loss and shear force but, no difference was found in objective meat quality characteristics of lambs from different treatments.}, issn = {1176-5283}, author = {Kok JC and Schreurs NM and Cranston LM and Corner-Thomas RA and Ekanayake WEMLJ and Morris ST and Kenyon PR} } @article {3672, title = {BRIEF COMMUNICATION: Conventional or Albrecht-Kinsey fertiliser approach in a commercial-scale dairy farm systems comparison}, journal = {New Zealand Journal of Animal Science and Production}, volume = {79}, year = {2019}, month = {07/2019}, pages = {100-102}, address = {Palmerston North}, abstract = {Long-standing questions around application of nutrients other than N, P and K (such as Mg and Ca), to meet either plant or soil requirements have been tested for the first time at a commercial dairy-farm-scale. Two dairy farms with similar soil type and soil management history were used to compare physical and financial productivity when the fertiliser regime followed either a conventional plant requirement approach (CON) or an Albrecht-Kinsey soil requirement approach (A-K). A longitudinal study commencing in 2012/13 included measurements of pasture and animal production, fertility and quality, and animal health. After six years there are no apparent impacts of fertiliser regime on milk yield or pasture growth, although less N fertiliser was applied on the A-K farm and this farm grew more clover. Though not statistically significant, there were more in-calf cows and fewer metabolic problems pre- and post- calving in the A-K farm system compared with the CON system. Setting up and maintaining the soils at target parameters cost more (+$532/ha fertiliser costs in the first year; +$197 in the last two years), but animal health costs were on average $56/ha/yr lower.}, issn = {1176-5283}, author = {Bryant RH and Zwart T and Greer G and Casey J and Solly K and Pinxterhuis I and Horrocks A and Gillespie R and Pellow R} } @article {3672, title = {BRIEF COMMUNICATION: Does stocking rate of singleton ewes during lambing and lactation affect performance?}, journal = {New Zealand Journal of Animal Science and Production}, volume = {79}, year = {2019}, month = {07/2019}, pages = {95-97}, address = {Palmerston North}, abstract = {The impact of singleton-ewe stocking rate (SR, 11, 13, 15 ewes ha) during lactation on ewe and lamb performance to weaning was examined over three years. Pasture mass before lambing in 2014 was considerably higher than that in both 2015 and 2016. At weaning in 2014 there was no effect (P>0.05) of SR on ewe live weight, while in 2015 and 2016, SR 11 ewes were heavier (P<0.05) at weaning than both SR 13 and 15 ewes. Lamb live weight during lactation was not affected (P>0.05) by SR in any year. Combined, these data suggest that when pasture mass is high, SR of up to 15 ewes per ha can be utilised but at lower pasture covers increasing SR will negatively affect ewe, but not lamb live weight. Farmers, therefore, need to consider carefully if they should utilise higher SR under these circumstances. }, issn = {1176-5283}, author = {Kenyon PR and Corner-Thomas RA and Cranston LM and Morris ST} } @article {3672, title = {BRIEF COMMUNICATION: Does the age and sex affect meat quality in older lambs}, journal = {New Zealand Journal of Animal Science and Production}, volume = {79}, year = {2019}, month = {07/2019}, pages = {98-99}, address = {Palmerston North}, abstract = {During a programme which targeted late-born heavy-weight lambs supplied at 14 months of age, the question was raised about the meat quality of old-season lambs compared to traditional new-season product. In Experiment 1, short loins from 10 new season ram lambs (3.5 months of age) and 10 old-season ram lambs (14 months of age) of similar weights and grades were compared. Samples from new-season lambs scored slightly better for most characteristics (taste P<0.10, tenderness P <0.001 and juiciness P<0.03) but there was no difference in odour (P <0.60) and few tasters disliked any of the samples. In Experiment 2, short loins from 10 ewe, nine cryptorchid and nine ram older lambs with similar carcass weights were compared. There were no significant differences in eating quality between the samples from ram, ewe and cryptorchid lambs. In conclusion, differences due to age were small when carcasses were compared at the same weight and carcass fatness. }, issn = {1176-5283}, author = {Thomson BC and Muir PD and Smith NB} } @article {3672, title = {BRIEF COMMUNICATION: Effect of a fodder beet or lucerne-chaff-based diet on triplet-bearing ewe live weight, body condition score and lamb birth weight}, journal = {New Zealand Journal of Animal Science and Production}, volume = {79}, year = {2019}, month = {07/2019}, pages = {168-170}, address = {Palmerston North}, abstract = {The objective was to determine whether a fodder-beet based diet (FB) balanced for crude protein, vitamins and minerals could support similar ewe live weight (LW), body condition score (BCS) and lamb birth weight compared to a lucerne-based diet. Triplet-bearing ewes (60-70 days gestation) were randomly allocated to a lucerne-based (65\% of dry matter [DM] n=12) or FB-based (56\% FB bulb; n=16) diet. Lambs were weighed two hours after birth. Ewe LW (P=0.970) and BCS (P=0.165) did not differ between treatments and there was no diet-by-day gestational age (dGA) interaction. A diet-by-dGA interaction was observed for DM intake (P=0.003) where FB-fed ewes consumed less than control ewes with advancing gestation. A diet-by-sex interaction was evident for lamb birth weight (P=0.026) where female lambs from FB-fed ewes were heavier than female lambs from control-fed ewes, with no difference between males. These results indicate that supplementing a FB-based diet with additional protein, fibre and minerals can maintain triplet-bearing ewe BCS and LW and improve female lamb birth weight compared to those born to control ewes.}, issn = {1176-5283}, author = {Knol FW and Erichsen C and Jonker A and Sandoval E and Pacheco D and Hea SY and McCoard SA} } @article {3672, title = {BRIEF COMMUNICATION: Effect of pre-weaning milk allowance on post-weaning behaviour of heifer calves on pasture}, journal = {New Zealand Journal of Animal Science and Production}, volume = {79}, year = {2019}, month = {07/2019}, pages = {84-86}, address = {Palmerston North}, abstract = {The objective of this study was to assess how pre-weaning milk allowance influences the grazing and rumination behaviour of dairy heifers on pasture after weaning. Group-housed heifer calves (n=28) were fed milk replacer at a low-allowance (LA; 10\% of initial live weight), high-allowance (HA; 20\% of initial live weight), and ad-libitum (ADLIB; free access) until 93 days of age. Heifers were then given access to pasture at 100 days of age, and were observed at 101, 108, 122 and 127 days of age. At 101 days of age, LA calves spent more time ruminating than HA and ADLIB calves, and spent less time grazing than HA calves (P<0.05). The time spent on each activity in subsequent weeks was the same among treatments. This indicates that any differences in foraging and rumination behaviour caused by pre-weaning milk allowance disappeared within a few weeks after weaning. }, issn = {1176-5283}, author = {Groenendijk ME and Lowe K and Schreurs NM and Khan MA} } @article {3672, title = {BRIEF COMMUNICATION: Greenhouse gas emissions from New Zealand sheep-and-beef farm systems}, journal = {New Zealand Journal of Animal Science and Production}, volume = {79}, year = {2019}, month = {07/2019}, pages = {56-60}, address = {Palmerston North}, abstract = {Agriculture was the single largest contributor (48.1\%) to total greenhouse gas (GHG) emissions in New Zealand in 2017, and sheep and beef livestock systems contributed about 40\% of these emissions. A holistic assessment of the farm-scale drivers of GHG emissions is critical to identifying opportunities to reduce emissions. We used farm-scale models to estimate feed inventories, nutrient flows and GHG emissions for 60 sheep and beef farms. The range in annual GHG emissions (methane (CH4) and nitrous oxide (N2O)) was 189 to 6,362 kg carbon dioxide (CO2) equivalents per hectare, demonstrating the diversity in sheep and beef systems. As stocking rate and animal product (wool + net carcass weight) per hectare increased, GHG emissions increased, although some farms exhibited 50\% higher emissions than others with similar animal product per hectare. The variation in GHG emissions across these farms indicates there is potential to reduce on-farm GHG emissions and remain productive and profitable.}, issn = {1176-5283}, author = {Hutchinson KJ and Rennie GM and Vibart RE and Mercer GJK and O{\textquoteright}Neil K and Burtt AN and Chrystal JM and Devantier B and Smiley DR and Taylor AL and Thompson BR and Wall AJ and Dynes RA} } @article {3672, title = {BRIEF COMMUNICATION: Impacts of live weight of ewe lambs at mating on their reproductive performance}, journal = {New Zealand Journal of Animal Science and Production}, volume = {79}, year = {2019}, month = {07/2019}, pages = {87-90}, address = {Palmerston North}, abstract = {This experiment investigated the impacts of heavier live weight of twin-born ewe lambs at mating on reproductive performance. Romney ewe lambs (n=270) were allocated to one of two groups: {\textquoteleft}Heavy{\textquoteright} (48.0{\textpm}3.8 kg), had been preferentially fed from weaning to breeding, or {\textquoteleft}Control{\textquoteright} (44.8{\textpm}3.5 kg). Both groups were exposed to crayon-harnessed vasectomised rams for 68 days before breeding, and then were bred to entire Romney rams for 34 days. Crayon marks were recorded every 17 days. Heavy ewe lambs were more likely to be mated in the first 17 days of breeding (69.9\% vs. 54.8\%, P<0.05), mated in the entire breeding period (85.1\% vs. 69.4\%, P<0.01) and had a greater litter size (0.99 vs. 0.65; P<0.01) than did Control ewe lambs. Heavier live weight at mating improved reproductive performance of ewe lambs. These results emphasise the importance of an adequate live weight at breeding for reproductive success in ewe lambs.}, issn = {1176-5283}, author = {Haslin E and Corner-Thomas RA and Kenyon PR and Morris ST and Pettigrew EJ and Hickson RE and Blair HT} } @article {3672, title = {BRIEF COMMUNICATION: Investigation of the water-soluble carbohydrates content of Plantain (Plantago Lanceolata L.)}, journal = {New Zealand Journal of Animal Science and Production}, volume = {79}, year = {2019}, month = {07/2019}, pages = {174-176}, address = {Palmerston North}, abstract = {Previous research has shown that the water-soluble carbohydrates (WSC) of Plantain (Plantago lanceolata L.) leaves differ from that of many other common forages. Analytical methods used to quantify WSC may underestimate the concentration of WSC in plantain herbage. To ascertain the suitability of current method, the conventional anthrone reaction method (AR) was compared against the phenol-sulphuric acid method (PSA). The WSC of eight plantain samples and one ryegrass sample were compared using AR and PSA against high-performance liquid chromatography (HPLC). The results showed that AR greatly underestimated the WSC content of plantain compared with PSA, which was similar to HPLC (7.18\%, 13.5\%, 14.7\% DM, respectively, P<0.001). The discrepancy between the results from AR and PSA was due to sorbitol, which was not detected using AR. }, issn = {1176-5283}, author = {Jiang S and Bryant RH and Jiao J and Tung R} } @article {3672, title = {BRIEF COMMUNICATION: Meat quality of light-weight, yearling steers of dairy origin}, journal = {New Zealand Journal of Animal Science and Production}, volume = {79}, year = {2019}, month = {07/2019}, pages = {156-158}, address = {Palmerston North}, abstract = {Loline, an alkaloid produced by Neotyphodium endophytes in pastoral grass species with potential antimicrobial properties, has several known derivatives; N-formyl loline (NFL), N-acetyl loline (NAL), N-acetyl norloline (NANL), N-methyl loline (NML), and loline base, though the availability and form during rumen fermentation and digestion is unclear. Festuca pratensis seeds either with (LOL) or without (NIL) lolines (150-200 {\textmu}g/mL) were incubated in either sterile or viable rumen fluid or in either HCL/pepsin (pH 2) or water (pH 7). At 72 hours LOL in sterile rumen fluid had 23\%, 26\%, and 45\% more NFL (P=0.05), NANL (P=0.04), and loline base (P=0.01) respectively, with 27\% more total loline present (P=0.06), and 65\% more NML (P=0.09) compared with LOL in viable rumen fluid. Loline tended to alter the fermentation pattern as NIL produced 11\% more ammonia (P=0.07), and 5\% less propionate (P=0.06) than LOL. In HCL/pepsin there were 38\%, 49\%, and 39\% more total lolines (P=0.05), NANL (P=0.02), and NFL (P=0.04) respectively, compared with water. Rumen and abomasal digestion appear to have a small effect on loline{\textquoteright}s form and concentration with only slight alteration to the rumen fermentation pattern. Presence of lolines had little evidence of an antimicrobial effect.}, issn = {1176-5283}, author = {Pike SJ and Schreurs NM and Hickson RE and Hunt JJ and Kenyon PR and Garrick DJ and Blair HT and Morris ST} } @article {3672, title = {BRIEF COMMUNICATION: Relative cost of producing carcasses from dairy-origin steers slaughtered at 8 {\textendash} 12 months of age in New Zealand}, journal = {New Zealand Journal of Animal Science and Production}, volume = {79}, year = {2019}, month = {07/2019}, pages = {153-155}, address = {Palmerston North}, abstract = {Loline, an alkaloid produced by Neotyphodium endophytes in pastoral grass species with potential antimicrobial properties, has several known derivatives; N-formyl loline (NFL), N-acetyl loline (NAL), N-acetyl norloline (NANL), N-methyl loline (NML), and loline base, though the availability and form during rumen fermentation and digestion is unclear. Festuca pratensis seeds either with (LOL) or without (NIL) lolines (150-200 {\textmu}g/mL) were incubated in either sterile or viable rumen fluid or in either HCL/pepsin (pH 2) or water (pH 7). At 72 hours LOL in sterile rumen fluid had 23\%, 26\%, and 45\% more NFL (P=0.05), NANL (P=0.04), and loline base (P=0.01) respectively, with 27\% more total loline present (P=0.06), and 65\% more NML (P=0.09) compared with LOL in viable rumen fluid. Loline tended to alter the fermentation pattern as NIL produced 11\% more ammonia (P=0.07), and 5\% less propionate (P=0.06) than LOL. In HCL/pepsin there were 38\%, 49\%, and 39\% more total lolines (P=0.05), NANL (P=0.02), and NFL (P=0.04) respectively, compared with water. Rumen and abomasal digestion appear to have a small effect on loline{\textquoteright}s form and concentration with only slight alteration to the rumen fermentation pattern. Presence of lolines had little evidence of an antimicrobial effect.}, issn = {1176-5283}, author = {Hunt JJ and Tozer PR and Kenyon PR and Schreurs NM and Pike SJ and Hickson RE and Blair HT and Garrick DJ} } @article {3672, title = {BRIEF COMMUNICATION: Urinary nitrogen excretion and water balance of dairy heifers fed cut plantain or perennial-ryegrass pastures}, journal = {New Zealand Journal of Animal Science and Production}, volume = {79}, year = {2019}, month = {07/2019}, pages = {171-173}, address = {Palmerston North}, abstract = {Loline, an alkaloid produced by Neotyphodium endophytes in pastoral grass species with potential antimicrobial properties, has several known derivatives; N-formyl loline (NFL), N-acetyl loline (NAL), N-acetyl norloline (NANL), N-methyl loline (NML), and loline base, though the availability and form during rumen fermentation and digestion is unclear. Festuca pratensis seeds either with (LOL) or without (NIL) lolines (150-200 {\textmu}g/mL) were incubated in either sterile or viable rumen fluid or in either HCL/pepsin (pH 2) or water (pH 7). At 72 hours LOL in sterile rumen fluid had 23\%, 26\%, and 45\% more NFL (P=0.05), NANL (P=0.04), and loline base (P=0.01) respectively, with 27\% more total loline present (P=0.06), and 65\% more NML (P=0.09) compared with LOL in viable rumen fluid. Loline tended to alter the fermentation pattern as NIL produced 11\% more ammonia (P=0.07), and 5\% less propionate (P=0.06) than LOL. In HCL/pepsin there were 38\%, 49\%, and 39\% more total lolines (P=0.05), NANL (P=0.02), and NFL (P=0.04) respectively, compared with water. Rumen and abomasal digestion appear to have a small effect on loline{\textquoteright}s form and concentration with only slight alteration to the rumen fermentation pattern. Presence of lolines had little evidence of an antimicrobial effect.}, issn = {1176-5283}, author = {Al-marashdeh O and Judson HG and Schetelat S and Pawsey A and Edwards GR} } @article {3672, title = {Can bone measures of the bovine metacarpus predict humeral bone structure?}, journal = {New Zealand Journal of Animal Science and Production}, volume = {79}, year = {2019}, month = {07/2019}, pages = {8-12}, address = {Palmerston North}, abstract = {Peak bone mass in cattle is influenced by factors prior to puberty and insufficient peak bone mass prior to the first lactation predisposes heifers to the risk of spontaneous humeral fractures. At post-mortem examination, affected heifers present with osteoporosis (reduced periosteal circumference and reduced cortical wall thickness). Due to its location, there is no cost-effective way to scan the humerus in the live animal. However, the metacarpal bones (MC3/MC4) are straightforward to scan in a live anaesthetised animal. The aim of this experiment was to determine if the metacarpal could be used to predict bone mass and material properties of the humerus. The left humerus and metacarpal bones were obtained from 57 cattle aged six weeks to eight years. Bones were scanned at the mid-diaphysis using peripheral quantitative computed tomography (pQCT), to obtain measures of bone mass and material properties (strength). Strong positive relationships were observed (R2=0.89 - 0.98, P<0.0001) for pQCT measurements of bone mass and strength. Thus, the metacarpus is a good predictor of bone content and material properties of the humerus across cattle of differing age and maturity. }, issn = {1176-5283}, author = {Gibson MJ and Rogers CW and Dittmer K and Hickson RE and Pettigrew EJ and Back PJ} } @article {3672, title = {Carbon footprint of two unique farms, compared with industry averages}, journal = {New Zealand Journal of Animal Science and Production}, volume = {79}, year = {2019}, month = {07/2019}, pages = {118-124}, address = {Palmerston North}, abstract = {Three years of data from a North Island breeding property (Onetai) and a South Island finishing property (Highlands) were modelled in Farmax and Overseer{\textregistered}, to estimate production, profitability and GHG emissions. On an annual basis, each hectare of Onetai averaged more than 100 kg meat and 25 kg of fibre across three years, worth $420/ha. On Highlands, each hectare produced 200 to 327 kg of meat and 20 kg of fibre, with revenue on average $737/ha, but varying between $433/ha in a drought and almost $900/ha in better seasons. GHG emissions (in CO2 equivalents CO2-e) ranged from 3106 to 3302 kg/ha at Onetai, and from 3043 to 5067 kg/ha at Highlands. The dramatic variation on the finishing farm was due to varying numbers of store stock purchased and finished according to available forage. Industry data for similar class farms modelled using the same software averaged around 3600 kg CO2-e /ha. Similar farms ($339/ha) were less profitable than Onetai, and finishing farms were less profitable than Highlands ($467/ha). Per hectare, all farms emitted similar amounts of GHG to literature values, but study farms produced more meat and greater financial returns. Greater efficiency of production is better for the pocket and the planet.}, issn = {1176-5283}, author = {Dynes RA and Scobie DR and Vibart RE and Rennie G and Hutchinson KJ and Taylor A and Moss RA and Dennis S and Wall A} } @article {3672, title = {Change in herbage nutritive value of mown and standing pasture under rotational grazing}, journal = {New Zealand Journal of Animal Science and Production}, volume = {79}, year = {2019}, month = {07/2019}, pages = {103-107}, address = {Palmerston North}, abstract = {Varying the regrowth interval, pre-graze herbage mass and mowing pasture prior to grazing are strategies used to try to improve pasture quality and nutrient availability to grazing livestock. This study compared the nutritive value of pastures which had been mown before grazing, or grazed as standing pastures following a long (Long, 28 days) or moderate (Mod, 21 days) regrowth interval. Nutritive value and dry matter percent were determined at 0, 1, 2, 3, 4, 6, 12 and 24 hours in replicated paddocks during a 24-hour grazing period following allocation to dairy cows at 0700 h. Due to previous grazing management, which maintained a high proportion of leafy material in the grazed stratum, the nutritive value of the available herbage before grazing was similar for all treatments. Mowing before grazing resulted in a relatively constant nutrient supply over a 24 h grazing period; however, this did not alter cow performance (e.g., milksolids production or BCS) compared with grazing standing pasture. By contrast preferential selection of higher quality pasture by cows grazing standing pasture resulted in lower concentration of herbage crude protein (P<0.05) and greater concentration of fibre (P<0.05) at the end of the grazing period. When pastures were mown, herbage wilted, increasing DM from 17.5 to 39.4\% DM within 24 hours (P<0.05). Despite large differences in pasture management, extending the regrowth interval and using repeated pre-graze mowing did little to alter herbage nutritive content.}, issn = {1176-5283}, author = {Bryant RH and Edwards P and Thomas C and Kay J and Clement A} } @article {3672, title = {Characterisation of the nutritional composition of plant components of a herb-clover mix during November to May in New Zealand}, journal = {New Zealand Journal of Animal Science and Production}, volume = {79}, year = {2019}, month = {07/2019}, pages = {162-167}, address = {Palmerston North}, abstract = {Animal performance on herb-clover mixes (containing plantain, chicory, red clover and white clover) can be inconsistent. Potentially this could be due to variation in botanical and nutritional composition of plant components affecting animal selectivity and, thus, performance. Herbage samples were collected monthly from November 2016 to May 2017, from 3 paddocks located at Massey University{\textquoteright}s Keeble farm, Palmerston North, New Zealand. Quadrat-cut samples were used to determine the herbage mass and botanical composition. Hand-plucked samples of each plant components were analysed for the nutritional composition. The botanical composition of the herb-clover mix differed over time (P<0.05). The percentage of chicory stems increased (9.2 to 16.2\%) and plantain stems decreased (14.7 to 1.0\%, P<0.001). Overall, the crude protein and metabolisable energy of white clover, red clover, plantain and chicory leaves were higher (P<0.05) than those of plantain and chicory stems in each month except in November. These data indicate that a higher proportion of chicory and plantain stems in a herb-clover mix would reduce overall metabolisable energy and crude protein. This information can be useful for farmers to manipulate both the botanical and nutritional composition of herb-clover mix to optimise animal performance.}, issn = {1176-5283}, author = {Ekanayake WEMLJ and Corner-Thomas RA and Cranston LM and Hickson RE and Kenyon PR and Morris ST} } @article {3672, title = {Circadian variation in methane emissions by cattle and correlation with level and composition of ryegrass-based pasture eaten}, journal = {New Zealand Journal of Animal Science and Production}, volume = {79}, year = {2019}, month = {07/2019}, pages = {61-64}, address = {Palmerston North}, abstract = {The objective of the study was to determine the circadian variation in CH4 emission from cattle fed ryegrass-based pasture offered in two meals a day and identify factors that affect this circadian variation. Methane emission data (expressed as g/d) of 15 respiration chamber trials with growing beef cattle (six trials) or non-lactating (three trials) and lactating (six trials) dairy cows was analysed. Minimum CH4 production rate, measured approximately every 3 minutes, in the 24 h day, among the 15 trials ranged from 51 g/d to 217 g/d, and maximum CH4 production rate ranged from 152 g/d to 471 g/d. The ratio of maximum to minimum CH4 production rate, indicating absolute circadian variation, among the 15 trials, ranged from 1.8-fold to 4.4-fold. This ratio correlated negatively with feeding level (r =- 0.57; P < 0.05) and within the growing and non-lactating cattle dataset, the ratio also correlated negatively with forage neutral and acid detergent fibre concentration (r = -0.74; P < 0.10) and positively with crude protein concentration (r = 0.77; P < 0.10). In summary, the magnitude of circadian variation in CH4 emissions decreased with increasing feeding level over the whole dataset and also with changing pasture composition within the growing and non-lactating animal dataset. }, issn = {1176-5283}, author = {Biswas AA and Jonker A} } @article {3672, title = {Deterministic modelling of nitrogen utilisation by horses managed under pasture-based, intensive and semi-intensive systems with different levels of pasture intake.}, journal = {New Zealand Journal of Animal Science and Production}, volume = {79}, year = {2019}, month = {07/2019}, pages = {1-7}, address = {Palmerston North}, abstract = {There are limited data on the average nitrogen (N) intake and N loss for the different classes of equine livestock, and the different equine production systems within New Zealand. Using a deterministic model, the total nitrogen excreted, and nitrogen partitioned into animal requirements, urine and faeces were estimated based on the crude protein requirement, digestible crude protein intake, and crude protein excreted in urine and faeces. Separate models were generated for five different livestock classes managed within three different production systems (commercial breeding farm, sport horse and racehorse). Overall, the N in diet (\%), the modelled daily N intake and N losses varied with the percentage of pasture in the diet. The faecal N loss remained consistent (20-25\%) across diets and horse classes whereas urinary N loss increased with daily N intake and percentage of pasture in the diet. Total N loss per day was estimated to be 0.18, 0.28, and 0.48 g N/kg body weight in racehorse, sport horse and Thoroughbred mares respectively. The N excretion per unit weight from young horses, racehorses and sport horses were substantially lower than that reported for ruminants. Therefore, horse-specific data should be used when modelling farm-level nitrogen excretion.}, issn = {1176-5283}, author = {Chin YY and Back PJ and Gee EK and Rogers CW} } @article {3672, title = {Effect of genetic merit for milk urea on milk production and efficiency of crude protein utilization of grazing cows with contrasting supplement inclusion}, journal = {New Zealand Journal of Animal Science and Production}, volume = {79}, year = {2019}, month = {07/2019}, pages = {112-117}, address = {Palmerston North}, abstract = {Milk urea (MU) has been proposed as a predictor of nitrogen excreted through urine into the environment. The objective of this study was to evaluate milk production performance and efficiency of crude protein utilization (ECPU) of cows with low and high MU breeding values (MUBV) in grazing conditions with two levels of dietary supplementation inclusion. From July 2016 to May 2017, 257 cows were milked once daily with low supplementation (LS; 366 kg/cow/lactation) and 210 cows were milked twice daily with high supplementation (HS; 2,091 kg/cow/lactation). Cows within each herd were ranked as low, intermediate, or high for MUBV. The dataset consisted of 2,318 records of milk production collected from monthly herd-tests of both herds; and 853 additional milk samples obtained at early, mid and late lactation to measure MU. The ECPU was calculated as the proportion of protein yield (PY) with respect to crude protein intake (CPI); with CPI derived from feed intake estimates based on energy requirements. Cows with HS had superior milk yield (MY) and milk solids yield (MSY) [MSY= PY + fat yield (FY)] (P<0.001). Feed intake was less in LS (P<0.001) but CPI was superior compared to HS. The ECPU was better in HS (P<0.001) because of higher PY (P<0.001) along with lower CPI (P<0.001). Levels of MU were superior for LS because of higher CPI. Cows with low-MUBV had significantly lower MU along with less total daily excretion of MU during the lactation (P<0.001). Irrespective of supplementary feed level, cows with low-MUBV had less MY (P<0.001). Low-MUBV did not result in improved ECPU for either supplementary feed level: under LS, ECPU was inferior in cows of low-MUBV (P<0.001), and this was explained by reduced PY (P<0.001).}, issn = {1176-5283}, author = {CorreaLuna M and Donaghy DJ and Kemp PD and Schutz MM and Lopez-villalobos N} } @article {3672, title = {The effect of herbage type prior to fasting on the rate of liveweight loss during fasting in ewe lambs}, journal = {New Zealand Journal of Animal Science and Production}, volume = {79}, year = {2019}, month = {07/2019}, pages = {131-134}, address = {Palmerston North}, abstract = {Animal performance on herb-clover mixes (containing plantain, chicory, red clover and white clover) can be inconsistent. Potentially this could be due to variation in botanical and nutritional composition of plant components affecting animal selectivity and, thus, performance. Herbage samples were collected monthly from November 2016 to May 2017, from 3 paddocks located at Massey University{\textquoteright}s Keeble farm, Palmerston North, New Zealand. Quadrat-cut samples were used to determine the herbage mass and botanical composition. Hand-plucked samples of each plant components were analysed for the nutritional composition. The botanical composition of the herb-clover mix differed over time (P<0.05). The percentage of chicory stems increased (9.2 to 16.2\%) and plantain stems decreased (14.7 to 1.0\%, P<0.001). Overall, the crude protein and metabolisable energy of white clover, red clover, plantain and chicory leaves were higher (P<0.05) than those of plantain and chicory stems in each month except in November. These data indicate that a higher proportion of chicory and plantain stems in a herb-clover mix would reduce overall metabolisable energy and crude protein. This information can be useful for farmers to manipulate both the botanical and nutritional composition of herb-clover mix to optimise animal performance.}, issn = {1176-5283}, author = {Semakula J and Corner-Thomas RA and Morris ST and Blair HT and Kenyon PR} } @article {3672, title = {Effect of in-vitro ruminal fermentation and HCL/pepsin digestion on loline}, journal = {New Zealand Journal of Animal Science and Production}, volume = {79}, year = {2019}, month = {07/2019}, pages = {13-19}, address = {Palmerston North}, abstract = {Loline, an alkaloid produced by Neotyphodium endophytes in pastoral grass species with potential antimicrobial properties, has several known derivatives; N-formyl loline (NFL), N-acetyl loline (NAL), N-acetyl norloline (NANL), N-methyl loline (NML), and loline base, though the availability and form during rumen fermentation and digestion is unclear. Festuca pratensis seeds either with (LOL) or without (NIL) lolines (150-200 {\textmu}g/mL) were incubated in either sterile or viable rumen fluid or in either HCL/pepsin (pH 2) or water (pH 7). At 72 hours LOL in sterile rumen fluid had 23\%, 26\%, and 45\% more NFL (P=0.05), NANL (P=0.04), and loline base (P=0.01) respectively, with 27\% more total loline present (P=0.06), and 65\% more NML (P=0.09) compared with LOL in viable rumen fluid. Loline tended to alter the fermentation pattern as NIL produced 11\% more ammonia (P=0.07), and 5\% less propionate (P=0.06) than LOL. In HCL/pepsin there were 38\%, 49\%, and 39\% more total lolines (P=0.05), NANL (P=0.02), and NFL (P=0.04) respectively, compared with water. Rumen and abomasal digestion appear to have a small effect on loline{\textquoteright}s form and concentration with only slight alteration to the rumen fermentation pattern. Presence of lolines had little evidence of an antimicrobial effect.}, issn = {1176-5283}, author = {Froehlich KA and Greer A and Bryant RH} } @article {3672, title = {Effects of maternal bromocriptine and melatonin treatments during early gestation on fetal lamb growth}, journal = {New Zealand Journal of Animal Science and Production}, volume = {79}, year = {2019}, month = {07/2019}, pages = {74-79}, address = {Palmerston North}, abstract = {Lower birth weights of autumn-born than of spring-born lambs may be due to a seasonal impairment of placental development, established by d84 of gestation, and perhaps mediated by high summer prolactin concentrations. This study attempted to determine whether reducing circulating summer prolactin concentrations in ewes during early gestation, using bromocriptine and melatonin, would improve placental and fetal growth and birth weights of autumn-born lambs. Pregnant mixed-age Romney ewes were randomly allocated to three treatment groups, balanced for age, live weight (LW) and source flocks, on d15 after mating. Ewes in the Bromocriptine group (n=20, LW 58.3{\textpm}6.7 kg) were injected with 50 mg Parlodel{\textregistered}LA, the Melatonin group (n=20, LW 58.6{\textpm}6.6 kg) each received one 18-mg Regulin{\textregistered} implant, while the Control group (n=21, LW 58.5{\textpm}5.8 kg) was injected with saline solution (0.9\% NaCl). At d139 of gestation, ewes were randomly allocated to a {\textquoteleft}Slaughter group{\textquoteright} sacrificed at d140-2 (n=30 LW 61.2{\textpm}5.6 kg) and a {\textquoteleft}Live-birth group{\textquoteright} (n=31, LW 60.0{\textpm}7.1 kg). Maternal plasma prolactin concentrations were significantly reduced by both bromocriptine (Control vs. Bromocriptine): 48.3{\textpm}9.2 vs. 0.7{\textpm}9.9 ng/ml (P<0.001) at d20 of gestation, and 82.6{\textpm}8.5 vs. 4.5{\textpm}9.1 ng/ml (P<0.001) at d40 of gestation, and melatonin treatments (Control vs. Melatonin): 82.6{\textpm}8.5 vs. 18.4{\textpm}9.5 ng/ml (P<0.001) at d40 of gestation, and 16.8{\textpm}3.7 vs. 2.9{\textpm}4.2 ng/ml (P<0.05) at d60 of gestation. Fetal plasma prolactin concentrations were not affected by treatments (Control vs. Bromocriptine vs. Melatonin): 32.4{\textpm}18.3 vs. 32.4{\textpm}19.1 vs. 59.8{\textpm}16.4 ng/ml. At d140 of gestation, there were no treatment effects (adjusted for sex and litter size) on fetal weight, crown-rump length, placental parameters, and maternal and fetal organ weights, except thymus reduced 20\% (P<0.05) by melatonin treatment. Birth weights and subsequent growth rates were similar among groups. Despite treatments reducing plasma prolactin concentrations there was no affect on placental or fetal growth, indicating that high prolactin concentrations early in pregnancy are not responsible for low birth weight in ewes lambing in May.}, issn = {1176-5283}, author = {Peterson SW and Wigati S and Jenkinson CMC} } @article {3672, title = {Estimates of genetic parameters for lactation curves for milk, fat, protein and somatic cell score in New Zealand dairy goats}, journal = {New Zealand Journal of Animal Science and Production}, volume = {79}, year = {2019}, month = {07/2019}, pages = {1-7}, address = {Palmerston North}, abstract = {There are limited data on the average nitrogen (N) intake and N loss for the different classes of equine livestock, and the different equine production systems within New Zealand. Using a deterministic model, the total nitrogen excreted, and nitrogen partitioned into animal requirements, urine and faeces were estimated based on the crude protein requirement, digestible crude protein intake, and crude protein excreted in urine and faeces. Separate models were generated for five different livestock classes managed within three different production systems (commercial breeding farm, sport horse and racehorse). Overall, the N in diet (\%), the modelled daily N intake and N losses varied with the percentage of pasture in the diet. The faecal N loss remained consistent (20-25\%) across diets and horse classes whereas urinary N loss increased with daily N intake and percentage of pasture in the diet. Total N loss per day was estimated to be 0.18, 0.28, and 0.48 g N/kg body weight in racehorse, sport horse and Thoroughbred mares respectively. The N excretion per unit weight from young horses, racehorses and sport horses were substantially lower than that reported for ruminants. Therefore, horse-specific data should be used when modelling farm-level nitrogen excretion.}, issn = {1176-5283}, author = {Scholtens MR and Lopez-villalobos N and Garrick DJ and Blair HT and Lehnert K and Snell RG} } @article {3672, title = {Estimation of heritabilities for milk urea and efficiency of crude protein utilization by day of lactation in a New Zealand dairy cow herd}, journal = {New Zealand Journal of Animal Science and Production}, volume = {79}, year = {2019}, month = {07/2019}, pages = {183-187}, address = {Palmerston North}, abstract = {The objective of this study was to estimate the heritability (h2) of milk urea (MU) and the efficiency of crude protein utilization (ECPU) in grazing dairy cows. Data consisted of 1,866 herd-test records for MU and ECPU from 380 cows. Genetic parameters for traits were estimated using a random regression test-day model (RRM). Herd-test date and parity had a significant effect on MU and ECPU suggesting that improvement of the traits can be made through management practices. Estimates of daily h2 ranged from 0.25 to 0.49 for MU and 0.02 to 0.41 for ECPU. The highest h2 estimates for both traits were found during late lactation. Genetic improvement of MU and ECPU should consider the genetic potential to change the lactation curves of these traits and their correlation with other productive and reproductive traits. }, issn = {1176-5283}, author = {Ariyarathne HBPC and CorreaLuna M and Blair HT and Garrick DJ and Lopez-villalobos N} } @article {3672, title = {Farm-management tools: reasons for the decision not to use specific tools}, journal = {New Zealand Journal of Animal Science and Production}, volume = {79}, year = {2019}, month = {07/2019}, pages = {125-130}, address = {Palmerston North}, abstract = {There are a large number of management tools available to farmers, however, some are utilised by only a small percentage. The reasons behind the choice not to use a particular tool were investigated using a postal questionnaire that was distributed to all New Zealand sheep farmers in 2014. Farmers were asked first to indicate from a list of 40 farm-management tools those they had used in the previous three years. For tools they had not used, they were asked to select one from a list of eight reasons. A total of 1659 usable questionnaires were received. The most commonly cited reason for not using any given tool was {\textquotedblleft}not relevant to my situation{\textquotedblright} (50.3\%) followed by {\textquotedblleft}benefits not apparent{\textquotedblright} (15.3\%) and {\textquotedblleft}it{\textquoteright}s an unwanted complication{\textquotedblright} (15.0\%). Demographic factors (age, education, gender, farm type and flock size) influenced the reasons for non-use of 20 of the 22 tools. Reasons for non-use of fecundity-boosting vaccine or quarantine treatment for footrot were not influenced (P>0.05) by any demographic factors. The results suggest that although many farmers do not see the relevance of particular tools to their enterprise, demographic factors can influence their reasons for not using a tool. }, issn = {1176-5283}, author = {Corner-Thomas RA and Kenyon PR and Morris ST and Ridler AL and Hickson RE and Greer AW and Logan CM and Blair HT} } @article {3672, title = {The feeding and management of Thoroughbred and Standardbred Racehorses displaying clinical signs of recurrent exertional rhabdomyolysis}, journal = {New Zealand Journal of Animal Science and Production}, volume = {79}, year = {2019}, month = {07/2019}, pages = {26-31}, address = {Palmerston North}, abstract = {Data on the feeding and management of racehorses and the prevalence of trainer-identified recurrent exertional rhabdomyolysis (RER) were collected via a cross-sectional face-to-face survey of 100 registered Thoroughbred and Standardbred trainers (n=1,771 horses). Data were collected on the number of horses in full work, number displaying signs of RER, gender, and age (<= 3 or > 3 years), amount and type of forage available, and weights of all forages and concentrates. The estimated crude RER prevalence was 8.4\% (95\% CI 7.2-10.8\%) with no significant difference in prevalence between breeds. Premixed feeds were fed to 98\% (1,742/1,771) of the total population, and 99\% (148/149) of the horses that displayed signs of RER. Feeds specially formulated for horses that {\textquotedblleft}tie-up{\textquotedblright} were fed to 50\% (75/149) of horses displaying RER signs. However, 64\% (48/75) of these had additional grain, or a standard racing feed, included in the diet. Average starch levels (\% of DE) provided to horses displaying signs of RER were 33.4{\textpm}1.1\%. Only 7\% (11/149) of horses displaying signs of RER were provided with dietary starch levels at the recommended allowance (< 20\% of DE). }, issn = {1176-5283}, author = {Wood IJ and Lancaster BE and Rogers CW} } @article {3672, title = {Growth and milk production of dairy heifers born to two-year-old or mixed-age dams}, journal = {New Zealand Journal of Animal Science and Production}, volume = {79}, year = {2019}, month = {07/2019}, pages = {135-139}, address = {Palmerston North}, abstract = {Keeping replacement heifers that were the progeny of primiparous cows mated by artificial insemination, enhances rates of genetic gain. Heifers that were the progeny of primiparous cows were lighter at birth and grew at a slower rate to first calving compared with heifers born to multiparous dams. Heifers that were heavier before first calving produced more milk than did lighter heifers. This study aimed to determine if there were liveweight (LWT) or milk-production disadvantages for heifers born from primiparous compared with multiparous dams. Data comprised of LWT records from 189,936 New Zealand dairy heifers. Dams were allocated to four groups according to their age: two (2yo; n=13,717), three (3yo; n=39,258), four to eight (4-8yo; n=120,859) and nine years old or greater (>=9yo; n=16,102). Heifers born to 2yo dams were lighter (P<0.01) from three to 21 months of age than heifers born to 3yo and 4-8yo dams. The progeny of 2yo and 3yo dams produced similar milksolids yields during their first lactation (304.9{\textpm}1.6 and 304.1{\textpm}1.5 kg, respectively), but more (P<0.01) than that of 4-8yo dams (302.4{\textpm}1.5) and >=9yo dams (P<0.001; 297.8{\textpm}1.6 kg). Heifers born to 2yo dams were lighter but produced more milk than heifers from older dams.}, issn = {1176-5283}, author = {Handcock RC and Lopez-villalobos N and Back PJ and Hickson RE and McNaughton LR} } @article {3672, title = {INVITED PAPER: Has progress been made in increasing the eco-efficiency of livestock systems?}, journal = {New Zealand Journal of Animal Science and Production}, volume = {79}, year = {2019}, month = {07/2019}, pages = {43-55}, address = {Palmerston North}, abstract = {Current challenges for New Zealand livestock farming systems include soil erosion, water quality, greenhouse gases (GHG), and indigenous biodiversity. Industry data were used to quantify changes in emissions of the major livestock sectors from 1990, by examining inputs (e.g., livestock numbers, fertiliser) and outputs (e.g., GHG, nitrate leaching (N), saleable products) using Overseer. Productivity gains were significant for extensive sheep and beef farms, from 107 (meat + wool) kg/ha in 1990 up to 167 kg/ha in 2012. Gains were modest for intensive sheep and beef farms in this period (from 219 up to 238 kg/ha). Extensive sheep and beef increased from 3370 to 3997 kg/ha of GHG and N leached from 12 to 14 kg/ha. Intensive sheep and beef farm systems showed negligible change in N leached, while GHG emissions rose from 4167 to 4470 kg CO2-e/ha. North Island dairy farms increased from 672 to 1000 kg milk solids/ha, from 11341 to over 12000 kg CO2-e/ha of GHG and N leached increased from 44 up to 50 kg/ha. All farm systems delivered more product in proportion to GHG and N per hectare per year. Potential scenarios for the sheep and beef sector into the future were investigated, by examining the influence of ongoing increases in reproduction of ewes, lamb growth, hogget lambing and moving away from breeding cows and older cattle could have on future productivity gains and environmental impact. With the area in pasture likely to continue to decline in extensive livestock systems as outstanding environmental issues are addressed, the potential exists to offset > 20\% of livestock GHG emissions. Intensive systems have fewer opportunities to make production and eco-efficiency gains, with less scope to reduce their impact. }, issn = {1176-5283}, author = {Mackay AD and Scobie DR and Rhodes TR and Devantier B} } @article {3672, title = {Livestock and pasture management on commercial Thoroughbred breeding farms: implications for estimating nitrogen loss}, journal = {New Zealand Journal of Animal Science and Production}, volume = {79}, year = {2019}, month = {07/2019}, pages = {65-70}, address = {Palmerston North}, abstract = {Published data on livestock and pasture management on Thoroughbred breeding stud farms were collated to model and estimate farm-level variables required to estimate nitrogen leaching. On commercial farms, stocking density doubled during the breeding season (August {\textendash} December). The effective stocking density increased with farm scale (number of resident mares) but decreased with farm size (total effective area). Therefore, farm nitrogen output may fluctuate seasonally and will be influenced by farm size and scale. Farm size and scale independently affected the stocking and grazing management (i.e., paddock rotation interval) for the different equine stock classes (empty, pregnant, mares with foals). Stocking and grazing management influenced the pasture available and subsequently, the grazing behaviour as determined by the difference between pasture mass of lawns and roughs. The difference between pasture mass of lawns and roughs was reduced with increasing stocking density and decreasing pasture availability, and increased under conditions of high stocking density (>2 mares/ha) and low pasture availability (<400 kg DM/ha/horse). Modification of grazing behaviour could affect the nitrogen-leaching potential by modifying the size of manure-deposition area and the N-loading rate on urine and dung patches. The complex relationship between farm, horse and management factors needs to be included when estimating nitrogen leached from equine properties.}, issn = {1176-5283}, author = {Chin YY and Back PJ and Gee EK and Rogers CW} } @article {3672, title = {Milk production and rebreeding performance of mixed-aged dairy cows mated to Angus or Hereford bulls}, journal = {New Zealand Journal of Animal Science and Production}, volume = {79}, year = {2019}, month = {07/2019}, pages = {144-148}, address = {Palmerston North}, abstract = {Approximately 72\% of New Zealand dairy cows are artificially mated to generate replacement heifers. There is an opportunity to mate the remaining dairy cows to beef bulls, generating a calf that has value as a beef-cross-dairy animal. Angus and Hereford are the predominant beef breeds in New Zealand, with Hereford the most common beef breed used in the dairy industry. The aim of this experiment was to determine whether there was a difference in milk production and rebreeding performance of mixed-aged dairy cows producing a calf sired by an Angus or Hereford bull, and if calf birth weight influenced these parameters. Cows were artificially bred to Angus or Hereford bulls. Service sire-breed had no effect on milk production in early lactation. Cows producing Angus-sired calves had a 2.4 kg greater 253-day protein yield (P<0.05) than did cows producing Hereford-sired calves, however, there was no effect of calf sire-breed on the 253-day yields of milk, fat and milksolids. The in-calf rate and inter-calving interval did not differ between service sire-breed. There was no effect of calf birth weight on milk production, in-calf rate or inter-calving interval. The results of this experiment suggest that there are no negative effects associated with artificially breeding cows to Angus compared to Hereford bulls. }, issn = {1176-5283}, author = {Coleman LW and Back PJ and Blair HT and Lopez-villalobos N and Hickson RE} } @article {3672, title = {Regression of traits-other-than-production phenotypes for cows milked once a day on estimated breeding values obtained from cows milked twice a day}, journal = {New Zealand Journal of Animal Science and Production}, volume = {79}, year = {2019}, month = {07/2019}, pages = {140-143}, address = {Palmerston North}, abstract = {The use of traits other than production (TOP) to aid selection for conformation fit-for-purpose offspring becomes more important as once-a-day (OAD) milking for whole or part season becomes more common. In 2013 Massey University Dairy 1 farm transitioned their mixed-breed herd milked twice a day (TAD) to an OAD spring-calving system. All cows on the farm were scored for 14 inspector TOP traits and four farmer-scored traits for a total of 1,163 records over five seasons (168 to 254 cows per year). The scores were adjusted for age of the cow and season. The adjusted phenotypes for all cows for each trait were then regressed on their corresponding nationally-produced TAD estimated breeding values (EBV), which had been calculated without using these phenotypes. The four farmer-scored traits had the lowest relationships with EBV. Estimates of regression coefficients near one were observed for the udder traits (udder support, rear udder, front teats, udder overall), dairy conformation and body capacity. This supports the use of national EBVs in OAD herds derived mostly from records on daughters in TAD herds. }, issn = {1176-5283}, author = {Sneddon NW and Lopez-villalobos N and Garrick DJ and Rocha JF and Donaghy DJ} } @article {3672, title = {Relationships between deer temperament and production traits}, journal = {New Zealand Journal of Animal Science and Production}, volume = {79}, year = {2019}, month = {07/2019}, pages = {32-36}, address = {Palmerston North}, abstract = {It is well-recognised by producers that the temperament of farmed deer (Cervus elaphus spp.) influences how they respond to management practices, such as transport and yarding, but less is known about how temperament influences productivity. This study aimed to investigate relationships among temperament and production parameters by analysing a data set (n=1647) of rising one-year-old deer. Four production categories (growth, immune function, eye muscle and reproduction) and five measures of temperament were recorded from weaning until either pre-slaughter or after first mating (3 to 12 or 18 months of age) at different ages depending on the trait. Temperament traits had low heritability estimates (h2=0.01 to 0.17, P>0.05), indicating genetic selection for these traits would be slow. The temperament traits of animals were generally consistent from weaning (at 3 months) until slaughter (at 10-12 months). Animals that were calm and easy to handle grew faster and may have better immune function compared to animals that were more agitated in the presence of humans. More research is needed to investigate the relationships between temperament, immune function, reproduction and productivity in farmed deer. }, issn = {1176-5283}, author = {Ward JF and Sch{\"u}tz KE and Wheeler M and Asher GW} } @article {3672, title = {Strategic feeding management to mitigate enteric methane emissions and urinary nitrogen excretion}, journal = {New Zealand Journal of Animal Science and Production}, volume = {79}, year = {2019}, month = {07/2019}, pages = {20-25}, address = {Palmerston North}, abstract = {MINDY, a mechanistic and dynamic dairy cow model was used to explore strategic feeding managements in early (EL) and late lactation (LL), with the aim of reducing enteric methane (CH4 g d-1) emissions and urinary N (UN g d-1) excretion, while maintaining milk production. Strategies explored were a factorial arrangement of (1) herbage allowances (20, 30, 40, or 50 kg d-1), (2) times of herbage allocation (AM or PM), (3) supplement types (barley grain, maize grain and silage) and (4) times of supplement allocation (AM, PM, or both). A Pareto front analysis was conducted to identify {\textquoteleft}best compromise{\textquoteright} treatments. Increasing herbage allowance increased consumption of fermentable carbohydrates and N, resulting in greater CH4 and UN emissions per cow. Allocating herbage in the PM rather than the AM increased dry matter intake by 1.9 and 1.7\% and milk solids (MS) by 2.3 and 0.7\% in EL and LL, respectively. Afternoon forage allocation produced more CH4 (5.1 and 3.6\%) and less UN (4.7 and 7.8\%) in EL and LL, respectively. Morning supplement allocation on average yielded the lowest CH4 and UN emissions. Results indicate that feeding management can mitigate both UN and CH4 however, MS production can be compromised depending on stage of lactation. }, issn = {1176-5283}, author = {Garrett K and Beck MR and Gregorini P} } @article {3672, title = {Using leafy turnip to maintain growth rates of dairy heifers during summer}, journal = {New Zealand Journal of Animal Science and Production}, volume = {79}, year = {2019}, month = {07/2019}, pages = {108-111}, address = {Palmerston North}, abstract = {In New Zealand, growth rates of dairy heifers can be restricted during late summer/early autumn due to inadequate pasture production and quality, which may delay puberty and compromise lactational performance, and, ultimately reduce their longevity in the herd and overall farm profits. The aim of this experiment was to determine the effect of feeding leafy turnip as an alternative summer forage to ryegrass-based pasture on the growth rate of heifers. Forty-five heifer calves aged six months were assigned to one of two treatment groups: (1) ryegrass-based pasture and (2) leafy turnip and were fed a combination of these feeds during summer/early autumn. Calves fed a greater proportion of leafy turnip were heavier (235.6 {\textpm} 3.8kg, P<0.05) and had greater average daily gain (0.74 {\textpm} 0.01 kg/day, P<0.05) than calves fed a greater proportion of pasture (218 {\textpm} 3.9 kg and 0.59 {\textpm} 0.01 kg/day), primarily due to pasture supply being restricted during the latter part of the experiment. The greater liveweight advantage from feeding leafy turnip remained for two months. Leafy turnip could be considered as an option to maintain growth rates of dairy heifers when pasture supply is restricted.}, issn = {1176-5283}, author = {YC Fan and Purchas GS and Hickson RE and Back PJ} } @article {3672, title = {Anthelmintic resistance: a perspective on our current understanding and ability to control this problem}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {105-108}, address = {Lincoln}, abstract = {Regimens to prevent the development of anthelmintic resistance (AR) have been promoted for many years. All reflect some appreciation of the selection pressure that different anthelmintic treatment policies apply to nematodes but AR is clearly more complicated than this for reasons we still do not yet understand sufficiently well. Whilst managing a refugia population on a farm is important to limit the development of AR there are many aspects that are not understood. Why is AR more common in some species than others, especially for some such as Dictyocaulus where there is clearly a short-lived refugia population and heavy selection pressure yet no recorded AR. The cost of AR to farmers has slowly escalated over the years and using a New Zealand example it can be estimated for a typical sheep farm that the cost of using a single active of an older anthelmintic such as levamisole compared to a newer anthelmintic such as monepantel is about NZ$3.27 per lamb raised. Diagnosis of AR continues to largely rely on the use of faecal egg count reduction tests. These are a very crude tool but generally acceptable for sheep. However, for cattle and farmed deer it is difficult to get egg counts high enough to conduct a meaningful test. Clearly more effort is needed to understand the mechanisms associated with AR and to develop better diagnostic tests so that farmers with their advisors are better able to achieve sustainable helminth control.}, issn = {1176-5283}, author = {Pomroy WE} } @article {3672, title = {Assessment of vigour in early life of dairy calves in New Zealand}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {161-164}, address = {Lincoln}, abstract = {Vigour of dairy calves in the first few days of life may be a relevant predictor of subsequent performance in an artificial-rearing system. This experiment aimed to evaluate two scoring systems to determine whether they detected variation in beef-sired calves born in the New Zealand pastoral dairy system. The scoring systems included a vigour score devised for housed dairy calves in Canada which had a range of physical and physiological parameters assessed, and a drinking score assessed at the feeder in the first few days of life (1=calf does not attempt to suck on feeder, 5=calf drinks vigorously for the whole feed). Calves generally scored highly (17-21 out of a possible 22 points) on the vigour score and meconium staining, head/tongue swelling, movement and heart rate showed little to no variation among calves. The drinking score showed that few calves scored in the low categories, and the scoring system may be improved by creating greater separation within the higher categories. Angus-cross calves were more likely to have a higher drinking score than Hereford-cross calves, and light or young calves were more likely to have low drinking scores.}, issn = {1176-5283}, author = {Gillingham J and Coleman LW and Back PJ and Mueller K and Hickson RE} } @article {3672, title = {BRIEF COMMUNICATION: Differential expression of lactoferrin and insulin-like growth factor-1 genes in milk from cows milked once and twice a day}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {109-110}, address = {Lincoln}, abstract = {Dairy farming in New Zealand has traditionally utilized a twice a day (TAD) milking system, but milking once a day (OAD) for the entire lactation is also practiced by a significant proportion of dairy farmers. This study reports on the differential gene expression in milk from OAD and TAD cows. Three predominant dairy breed group of New Zealand, Holstein-Friesian (F), Jersey (J) and F{\texttimes}J crossbred (F{\texttimes}J) were included in samples collected from both milking regimens. RNA was extracted from milk from 45 OAD and 42 TAD dairy cows during early lactation, and used to determine lactoferrin (LF) and insulin-like growth factor-1 (IGF-1) gene expression using qPCR. Compared to TAD cows, cows milked OAD had higher expression of the LF gene (1.38 vs 1.30 folds, P=0.08) and the IGF-1 gene (1.65 vs 1.48 folds, P=0.09). These results suggest that milking frequency affects the expression of milk composition genes at early lactation.}, issn = {1176-5283}, author = {Gedye K and Notcovich S and CorreaLuna M and Ariyarathne P and Heiser A and Lopez-villalobos N} } @article {3672, title = {BRIEF COMMUNICATION: Effect of maternal diet in late gestation on development of dairy calves}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {186-188}, address = {Lincoln}, abstract = {To investigate whether feeding strategies to reduce urinary N excretion would have negative effects on calf development, two feeding systems were compared. A total of 190 pregnant, Friesian {\texttimes} Jersey dairy cows were randomly allocated to one of two groups and offered either a low crude protein diet of maize silage and fodder beet (LCP) or a moderate CP diet of lucerne silage and fodder beet (MCP) for eight weeks prior to calving. Apparent metabolisable energy (ME) intake of dams was similar (110 MJME/cow/day) but CP concentration was greater for MCP than LCP (13.4 vs 7.5\% of the DM). There was no effect of maternal diet on calf birth weight (33.0{\textpm}0.5 kgLW) or morphometric measurements; heart girth (72.8{\textpm}0.5) spine length (54.4{\textpm}0.4) or hip height (73.1{\textpm}0.4 cm). These results suggest that dietary protein restriction in late gestation does not have any immediate negative effects on in utero calf development.}, issn = {1176-5283}, author = {Moonsan Y and Thomas C and Bryant RH and Edwards GR} } @article {3672, title = {BRIEF COMMUNICATION: Effect of timing of maize silage supplementation on grazing behaviour of dairy cows during a short grazing session on a ryegrass-based herbage}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {31-34}, address = {Lincoln}, abstract = {The objective of this experiment was to compare rumen degradation characteristics of ryegrass (Lolium perenne), white clover (Trifolium repens) or plantain (Plantago lanceolata) harvested either in the morning (0700) or afternoon (1600). Fresh herbage material from each treatment was weighed into duplicate nylon bags and incubated in four lactating Jersey {\texttimes} Friesian dairy cows with rumen fistula. Differences in nutritive value between forage types was greater than effect of harvest time as was the effect on rumen degradation characteristics. Plantain had faster (P<0.001) DM disappearance rates than perennial ryegrass-white clover (12.2 vs 8.80 \%/hr). The soluble fraction was greater (P=0.001) for forages harvested in the afternoon (25.2\% of DM) than those in the morning (15.4\% of DM) regardless of forage type. Nitrogen degradation was almost complete (>95\% of N) and similar for all treatments (P>0.05). An interaction for effective degradability revealed there was no effect of harvest time on DM and OM for plantain. However, perennial ryegrass-white clover harvested in the afternoon has a greater effective degradability of DM and OM than that harvested in the morning. This suggested there is a larger influence of harvest time on some degradation characteristics of perennial ryegrass-white clover compared with plantain.}, issn = {1176-5283}, author = {Al-marashdeh O and Gregorini P and Edwards GR} } @article {3672, title = {BRIEF COMMUNICATION: Impact of maternal plane of nutrition, ewe weight and twinning on fetal mammary gland development in sheep}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {183-185}, address = {Lincoln}, abstract = {This study evaluated the effects of maternal nutrition, weight and gestation rank on fetal mammary gland development. Light (L) and heavy (H) single- and twin-bearing ewes were fed ad libitum (A) or maintenance (M) nutritional regimens from day 21 to day 140 of gestation and euthanised for tissue collection. Plane of maternal nutrition or maternal weight did not affect histomorphometry of fetal mammary glands. Singleton fetuses had 43\% greater total duct area (P<0.05), 62\% greater secretory cell area and 32\% fewer ducts (P<0.05) but similar total lumen area, cell size and total cell number than twins. These results indicate that twinning reduces area of mammary ducts and secretory cell area while maternal weight and plane of nutrition from day 21 have little impact on mammary morphology at day 140 of gestation.}, issn = {1176-5283}, author = {McCoard SA and Adiletta AM and Jenkinson CMC and Peterson SW and Kenyon PR and Blair HT} } @article {3672, title = {BRIEF COMMUNICATION: Milk production, feeding behaviour and rumen fermentation of dairy cows supplemented with winter brassica crops}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {125-127}, address = {Lincoln}, abstract = {This study evaluated feeding behaviour, dry matter intake (DMI), rumen fermentation and milk production responses of lactating dairy cows supplemented with kale or swedes. Twelve multiparous early lactation dairy cows were randomly allocated to three dietary treatments in a replicated 3 x 3 Latin square. The control diet comprised 10 kg dry matter (DM) of grass silage, 4 kg DM of grass pasture and 8.8 kg DM of concentrate; 25\% of the diet was replaced with kale or swedes. Cows supplemented with kale showed a lower DMI compared to cows supplemented with swedes and the control diet; whereas swedes supplementation increased eating time. Milk production responses were not affected by winter brassica supplementation. This resulted in a greater feed conversion efficiency of cows supplemented with kale compared to that of the control diet.}, issn = {1176-5283}, author = {Keim JP and Rodriguez JR and Balocchi O and Pulido R and Pacheco D and Muetzel S} } @article {3672, title = {BRIEF COMMUNICATION: Milk production responses and rumen fermentation of dairy cows supplemented with summer brassica crops}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {122-124}, address = {Lincoln}, abstract = {This study evaluated the dry matter intake (DMI), rumen fermentation and milk production responses of lactating dairy cows supplemented summer brassicas. Twelve multiparous lactating dairy cows were randomly allocated to three dietary treatments in a replicated 3 x 3 Latin square design. The control diet was composed of 16.2 kg DM of grass silage and 4.5 kg DM of concentrate; 25\% of the diet was replaced by rape or turnip. Cows supplemented with summer brassicas showed a lower DMI (P<0.001) compared to the control diet, however milk yield was not affected, resulting in a greater feed conversion efficiency (1.35 for turnip and rape v/s 1.27 for the control diet). Rape supplementation significantly increased microbial protein (P=0.002). VFA concentration and the relative proportion of propionate were increased with turnips, whereas rape increased the acetate:propionate ratio. Mid-lactating dairy cows fed with brassicas are able to maintain production despite the reduced intake, probably due to improved rumen fermentation and therefore nutrient utilisation.}, issn = {1176-5283}, author = {Keim JP and Castillo M and Balocchi O and Pulido R and Pacheco D and Muetzel S} } @article {3672, title = {BRIEF COMMUNICATION: Potential alterations in New Zealand sheep, beef cattle and deer numbers due to climate change: what can genetics offer?}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {146-150}, address = {Lincoln}, abstract = {Many producers of red meat in New Zealand run enterprises consisting of a mix of sheep, beef cattle and deer, with obvious differences in species ratios across regions when aggregated. The aim of this study was to use these regional species ratios to predict livestock number changes in New Zealand in response to climate change. Simple linear regression was performed using mean temperature and species ratio (sheep, beef cattle and deer) for each region. The slopes of these linear equations were used to estimate {\textquotedblleft}business-as-usual{\textquotedblright} for each region in year 2100 under different models of climate change. An overall decrease in sheep and deer numbers by up to 38\% and 75\%, respectively, is predicted, along with an increase in beef cattle numbers by up to 60\%. Genetics provides an opportunity to select for animals that are adapted to the changing environment through reproductive plasticity, disease resistance, and heat tolerance, and therefore to moderate these predicted changes.}, issn = {1176-5283}, author = {Mcrae KM and Rowe S and McEwan JC} } @article {3672, title = {BRIEF COMMUNICATION: Re-designing New Zealand{\textquoteright}s productivist livestock production systems: Current strategies and next steps}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {132-136}, address = {Lincoln}, abstract = {Intensive, monotonous and specialized pastoral livestock production systems (productivist systems) are under significant pressure to reduce environmental impacts, increase biodiversity, animal welfare, and resilience. Efficiency/substitution strategies have been advanced to improve them, focusing on adjusting system components to reduce externalities of regulatory concern. They have received much research attention, policy and farmer support. However, many argue environmental impacts are not sufficiently reduced, and biodiversity, animal welfare and resilience remain unchanged. Biodiversity farming strategies have also been promoted, based largely on their application to less productive land. They are more spatially and/or temporally complex, less specialized, and promise to reduce multiple environmental impacts, improve support for biodiversity, animal welfare and increase resilience. However, few systems have been designed for highly productive land, there is insufficient amount of supporting research, and less policy support and awareness among farmers. Therefore, there is a high degree of uncertainty about their supporting farming practices, ecosystem services, and viability. Through multi-disciplinary research teams, and holistic and expanded spatial and temporal perspectives, Universities can play a key role in exploring, ex ante evaluating, and demonstrating new innovative system alternatives, that reduce this uncertainty and facilitate the transition to healthier viable animal production systems.}, issn = {1176-5283}, author = {McWilliam W and Gregorini P} } @article {3672, title = {BRIEF COMMUNICATION: Reproductive performance of herds milked once a day all season compared with herds milked twice a day all season}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {170-172}, address = {Lincoln}, abstract = {The objective of this study was to compare the reproductive performance of herds milked once a day (OAD) for the whole season with that of herds milked twice a day (TAD) for the whole season. Herds were classified as OAD or TAD if they herd tested >= three times a season and >90\% of animals had the same milking regime (OAD or TAD) at each test. Once the OAD herds were identified, the closest geographical TAD herd was identified and included in the dataset for the 2014 to 2016 seasons. Only herds with a Detailed InCalf Fertility Focus report were analysed (OAD n=75, TAD n=76). The means of five key reproduction measures were analysed and the means were significantly different for all measures (P<0.001). The OAD herds had a 7.7\% higher mean herd 3-week submission rate (OAD=84.6\%, TAD=76.9\%), 7.9\% higher mean conception rate (OAD=60.1\%, TAD=52.2\%), 10.4\% higher mean 6-week in-calf rate (OAD=74.8\%, TAD=64.4\%), 4.8\% lower mean not-in-calf rate (OAD=12.8\%, TAD=17.6\%), and 4.3\% more of the herd calved by week six of calving (OAD=88.2\%, TAD=83.9\%) than TAD herds. These results indicate that herds milking OAD for the whole season have, on average, better reproductive performance than those milked TAD the whole season.}, issn = {1176-5283}, author = {Hemming NV and McNaughton LR and Couldrey C} } @article {3672, title = {Calf-rearing systems on dairy farms and specialist calf rearing units: results of a New Zealand survey}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {173-176}, address = {Lincoln}, abstract = {Calf-rearing practices were surveyed on 297 dairy farms with an average of 82 heifer and 24 bull calves reared. Only 21\% of the properties fed colostrum immediately on arrival at the dairy shed, and 30\% did not feed their calves for at least 8 hours after pickup. Rearing systems were highly variable although most fed twice a day on high milk volumes. Many (40\%) did not know how much milk they fed to their calves and for those who did, the average was 316 litres per calf. Calves were weaned off milk at an average of 9.7 weeks. Calf-rearing practices were surveyed on 100 bull-calf-rearing properties rearing on average 259 calves annually. Larger rearers (>600 calves) tended to feed whole milk whereas smaller rearers tended to feed calf-milk replacers. Most rearers fed milk once a day and fed an average of 155 litres/calf over rearing. Calves were weaned at an average of 6.5 weeks. Bullcalf rearers feed to a weight target and a budget which resulted in a greater focus on performance and feed costs. Dairy farmers could significantly reduce both costs and time inputs by monitoring performance, feeding milk once a day and weaning earlier.}, issn = {1176-5283}, author = {Thompson BC and Muir PD and Ward KR} } @article {3672, title = {Characteristics of the grazing and farm management of broodmares on commercial Thoroughbred stud farms during spring}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {88-91}, address = {Lincoln}, abstract = {Thoroughbred broodmares in New Zealand are at greater odds of exposure to Leptospira than racehorses, possibly as a result of aspects of the on-farm pasture-based management. To identify biologically plausible risk factors cohorts of broodmares were prospectively followed on four Thoroughbred stud farms for a five-week period during the 2017-2018 season. Up to three cohorts of mares within each group of mares identified at the start of the study as empty (not in foal), in-foal, or mares having just foaled (with foal at foot) were followed on each farm and measurements made of pasture dry matter (DM) on offer, paddock location, mare cohort structure and farm management. The farm with stallions had a greater number of changes in mare cohort membership (2 (1-2) vs. 0 (0-1), P=0.001). The total pasture DM on offer was least for empty mares compared to in-foal mares, and mares with foals at foot (1483 (1157-2380) vs. 2070 (1499-2534) vs. 2299 (1390-3196) kg DM/ha, P=0.009). Pregnant mares had the greatest stocking density 4 (2 -6) mares/ha, due to use of small foaling paddocks. The low pasture DM on offer and high stocking rate for empty mares may provide a mechanism for exposure to environmental sources of Leptospira.}, issn = {1176-5283}, author = {Bengtsson J and Rogers CW and Back PJ and Emanuelson U and Roca J and Gee EK and Bolwell CF} } @article {3672, title = {Differences in birth weight and neonatal survival rate of lambs born to ewe hoggets or mature ewes}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {16-20}, address = {Lincoln}, abstract = {This experiment investigated differences in birth weights and survival in lambs born to hogget and mature ewes. It included 1082 mature ewes with a scanning rate of 1.87 fetuses per ewe joined and 1026 hoggets with a scanning rate of 0.80 fetuses per hogget joined, that were bred together, and lambed separately, under commercial farming conditions. At lambing, birth weight, lamb vigour score, and ewe maternal behaviour score were recorded. Lambs born to hoggets were lighter and less vigorous than lambs born to mature ewes (P<0.05). Single-born lambs were heavier at birth (P<0.05), and had greater survival at birth (P<0.05) than did twin-born lambs. Twin-born lambs were heavier (P<0.05) at birth, and had greater survival at birth (P<0.05) than triplets. There was an interaction of dam age and birth rank on lamb survival to weaning (P<0.01). At all birth ranks lambs born to hoggets had lower survival to weaning than lambs born to mature ewes, and the difference in survival increased with increasing birth rank. Lambs that had a vigour score of 1 had lower survival (83.5\%; P<0.05) than lambs that had a vigour score of either 2 or 3 (88.6- and 91.4\%, respectively). Maternal behaviour score did not affect lamb survival (P>0.05). Lambs born to hoggets are at greater risk of mortality, so farmers need to prioritise their time and resources towards hoggets at lambing time.}, issn = {1176-5283}, author = {Pettigrew EJ and Hickson RE and Blair HT and Griffiths KJ and Ridler AL and Morris ST and Kenyon PR} } @article {3672, title = {Economic value of productive life of cows on organic dairy farms in the United States}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {128-131}, address = {Lincoln}, abstract = {Organic milk production is an important sector of the US dairy industry. Productive life, defined as the time that a cow remains in the herd after first calving, is a trait of economic importance in organic dairy farming affecting the age structure of the herd and replacement costs. Productive life is of economic importance for inclusion in breeding objectives for organic milk production, which determine its value for selection. The objective of this study was to estimate the economic value (EV) of productive life for cows on certified organic dairy farms in the US using a farm-simulation model. Annual net farm income (NFI) per cow was calculated as gross income minus production costs. Income was derived from the sale of milk, disposed animals and other income. Milk income was calculated as US$ 0.809/kg milk. Cost of organic feed was US$ 0.308/kg DM. The average productive life of the herd was 1,302 d with an annual replacement rate of 22.1\%. The herd NFI was US$ 520.70/cow and the EV for productive life was US$ 1.24/d. This value is higher than the EV of productive life included in the Net Merit (US$ 0.69/d) or Grazing Merit (US$ 0.43/d) indexes used for conventional US dairy cattle.}, issn = {1176-5283}, author = {Lopez-villalobos N and Schinckel AP and Schultz MM} } @article {3672, title = {Effects of a daily dose of zeolite on rumen ammonia of lactating dairy cows consuming fresh-cut ryegrass pasture}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {137-141}, address = {Lincoln}, abstract = {Zeolites are aluminosilicates that can be safely fed to ruminants on a daily basis. They have a strong affinity for cations, including ammonium (NH4 +), which creates the potential to adsorb excess ammonium released in the rumen and reduce urinary nitrogen (N) excreted. The main objective of this proof-of-concept study was to evaluate the effect of a single dose of 300 g of zeolite, deposited into the rumens of cannulated dairy cows before the main morning meal of fresh-cut ryegrass pasture, on changes in rumen ammonium concentrations over the following 8 h. The two-week trial was a cross-over design with 12 cows, either fed ryegrass as a sole diet (Control) or with zeolite (Zeolite). There was a consistent trend for rumen ammonium concentrations in the zeolitetreated cows to increase more slowly over time, and were lower than control cows 8 h after the zeolite was given (P = 0.08). This study provides some indications that a daily dose of zeolite, fed at the onset of the morning meal, may have a moderating effect on rumen ammonium concentration, and reduce plasma urea N concentrations in lactating dairy cows fed a ryegrass-dominant diet.}, issn = {1176-5283}, author = {Beukes PC and Gregorini P and Waghorn GC and Selbie PB} } @article {3672, title = {Effects of early weaning onto herb-clover mixes on lamb carcass characteristics}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {189-193}, address = {Lincoln}, abstract = {Ewes and their twin lambs (weighing at least 16 kg) were allocated to three treatments: lambs with dams on ryegrass-white clover (RG-WC) pasture until 15 weeks of age (GRASS) (lambs; n=50), lambs with dams on herb-clover mixes (plantain, chicory, red and white clovers) until 15 weeks of age (HERB) (lambs; n=50), and lambs weaned early (8 weeks old) onto herb-clover mixes and dams on RG-WC pasture (EARLY) (lambs; n=50). Average daily gain, GR soft-tissue depth and muscularity of lambs in EARLY and GRASS were lower than those in the HERB treatment (P<0.05). The muscle to bone ratio of lambs in HERB treatment was higher than those in the EARLY treatment (P<0.05). Lambs can be weaned at 8 weeks of age onto herb-clover mixes to achieve similar carcass characteristics compared to lambs weaned at 15 weeks of age on RG-WC pasture. Lambs weaned early onto herbclover mixes had lower growth rates than the lambs not weaned early on herb-clover mixes. There were no negative effects on lamb carcass characteristics and lean-meat yield (LMY) when lambs were slaughtered at a set weight.}, issn = {1176-5283}, author = {Wong HX and Schreurs NM and Corner-Thomas RA and Ekanayake WEMLJ and Cranston LM and Morris ST and Kenyon PR} } @article {3672, title = {Effects of lamb live weight, sex and forage type (grass or plantain-clover mix) on lamb growth during summer}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {199-203}, address = {Lincoln}, abstract = {Two studies were carried out, over consecutive summers, to examine the effect of lamb sex and initial live weight on liveweight gain when grazing a grass-based sward (undeveloped hill country pasture) or a plantain-clover mix (plantain, red clover and white clover sown on cultivatable hill country). There were no interactions (P>0.05) between the sex of the lamb, initial live weight or forage type on lamb liveweight gain. In year 1, ewe lambs grew at a slower rate than wethers (169 vs 181 g/day; P<0.01), but there was no difference between the two sexes in year 2 (P>0.05). In both years lambs with a lighter initial liveweight profile were also lighter (P<0.001) at the end of the study, but there was no difference (P>0.05) in the liveweight gains of the light and heavy lambs. In both years lambs grazing the plantain-clover mix grew 47-141 g/day faster than did lambs grazing the grass-based sward (P<0.001). This indicates that the plantain-clover mix can be utilised for a range of lamb classes, with similar positive results.}, issn = {1176-5283}, author = {Cranston LM and Schreurs NM and Corner-Thomas RA and Kenyon PR and Morris ST} } @article {3672, title = {Effects of vehicle type, driver experience and transport management during loading and in-transit on the welfare of road transported horses in New Zealand}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {92-95}, address = {Lincoln}, abstract = {The transport of horses for pleasure and commerce occurs frequently in New Zealand. In contrast to commercial livestock transport, most are transported by nonprofessional drivers in vehicles accommodating 2-3 animals; these do not have design standards that specifically address livestock welfare. The study identified if vehicle type and other factors were associated with transport related behavioural problems (TRBPs) during loading and in-transit. An online survey addressing transport practices and TRBPs was distributed throughout the New Zealand horse industry. Univariate and multivariate analyses identified risk factors for TRBPs (P<0.2) during loading and in-transit. Use of a whip or food during loading, feeding en route, travel frequency, and transport vehicle type were risk factors for TRBPs during loading (P<0.02). The ability to assess horse distress, feeding en route, the use of a whip for loading and vehicle type were risk factors for TRBPs in-transit (P<0.03). Commercial transport and transport in large trucks were associated with TRBPs during loading and in-transit respectively. Findings support other published evidence that adverse welfare outcomes for horses may be associated with vehicle types and other factors. Further study is required to differentiate the role of vehicle design or type from horse loading and transport practices in New Zealand.}, issn = {1176-5283}, author = {Riley CB and Rogers CW and Padalino B} } @article {3672, title = {Faecal avoidance in Romney sheep lines selected for resistance or resilience to gastro-intestinal nematodes}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {100-104}, address = {Lincoln}, abstract = {Faecal avoidance was assessed in Romney lambs from lines selected for resistance or resilience to gastro-intestinal nematode parasites. Ten lambs from each selection line that were maintained in separate farmlets and naturally exposed to parasites were assessed on distance grazed from either a mud-clay or faecal ball at 130, 150, 180 and 210 days-of-age. Resistant line animals maintained lower faecal-egg counts compared with resilient lambs, viz. 25.6 c.f. 771.0 eggs per gram of faeces (P<0.001) and greater Trichostrongylus colubriformis-specific immunoglobulin G absorbance (P=0.005) indicating differences between selection lines in parasite loading and immunlogical status. Grazing distance from the object was greatest for faecal ball, viz. 11.53 {\textpm} 1.14 cm compared with mud-clay ball, viz. 4.19 {\textpm} 1.00 cm (P<0.001) and decreased with time (P<0.001). Grazing distance tended to be greater for resilient, viz. 8.63 {\textpm} 1.14 cm than resistant, viz. 7.09 {\textpm} 0.99 cm (P=0.09) but there was no interaction between selection line and ball type (P=0.709) indicating similar levels of faecal-specific aversion between the selection lines. These results suggest that the lesser infection levels in resistant-line animals when grazing is unlikely to be due to reduced exposure to infective larvae as a consequence of greater faecal avoidance.}, issn = {1176-5283}, author = {Hamie JC and Logan CM and McAnulty RW and Greer AW} } @article {3672, title = {Genetic and phenotypic correlations between production traits and adult body condition scores in New Zealand merino ewes}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {71-75}, address = {Lincoln}, abstract = {Genetic and phenotypic correlations between adult body condition scores (BCS) throughout the production cycle and eye muscle depth, fat depth, two-year-old greasy fleece weight, fibre diameter, staple length and staple strength were estimated from 2,007 pedigree-recorded merino ewes born between 2013 and 2015. The heritability estimates of BCS at pre-mating, mid-pregnancy, pre-lambing and weaning were 0.66, 0.39, 0.46 and 0.32 respectively. The heritability estimates for yearling greasy fleece weight, fibre diameter and staple length were 0.65, 0.86 and 0.73 respectively, and all these traits were positively genetically correlated with BCS. The genetic correlations among the four BCS measurements ranged from 0.39-0.83, while the phenotypic correlations ranged from 0.22-0.45. Genetic correlations between BCS and fat depth ranged from 0.67 to 0.83. Given the high heritability of BCS and high genetic correlations between BCS measurements, there is clear scope for selection to alter BCS. Mating appears to be the best time to record BCS for genetic selection, as it had the greatest heritability estimate and the greatest genetic correlations with ultrasound measurements of fat depth and eye-muscle depth and all wool traits except fibre diameter coefficient of variation and greasy fleece weight.}, issn = {1176-5283}, author = {Tait IM and PR Kenyon and Garrick DJ and Pleasants AB and Hickson RE} } @article {3672, title = {Genetic parameters for milk urea concentration and milk traits in New Zealand grazing dairy cattle}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {56-61}, address = {Lincoln}, abstract = {The aim of this study was to estimate genetic parameters for milk urea (MU), yields of milk (MY), fat (FY), crude protein (CPY) and lactose (LY), concentrations of fat (FP), crude protein (CPP) and lactose (LP) and efficiency of crude protein utilisation (ECPU) in grazing dairy cows. Data consisted of 1284 herd-test records of milk traits and MU from 468 mixed-breed cows in two herds. Univariate and bivariate repeatability animal models were used to estimate heritabilities (h2) and genetic (rG) and phenotypic (rP) correlations among the traits. Estimates of h2 for MU and ECPU were 0.24 and 0.11, whereas h2 estimates for MY, FY, CPY and LY ranged from 0.10 to 0.20. Estimates of h2 for FP, CPP and LP were 0.37, 0.59 and 0.19, respectively. The estimates of rP for MU with other traits were near zero. The rG of MU with MY (0.38), and of MU with LY (0.31) were positive and significant (P<0.01) whereas the rG of MU with FP (-0.80), CPP (-0.66) and LP (-0.76) were negative and significant (P<0.01). The rG between MU and ECPU was -0.09. These estimates of genetic parameters can be used to predict genetic responses to selection for reduction of MU.}, issn = {1176-5283}, author = {Lopez-villalobos N and CorreaLuna M and Burke JL and Sneddon NW and Schultz MM and Donaghy DJ and Kemp PD} } @article {3672, title = {Genetic parameters of GreenshellTM mussel traits under two harvest seasons}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {66-70}, address = {Lincoln}, abstract = {Greenshell{\texttrademark} mussels (GSM) are a mollusc endemic to New Zealand and are of economic importance to the New Zealand aquaculture industry. The primary focus of the GSM industry is selection for increased meat weight, however, aesthetics also influence marketability. This study focused on pedigree-based estimation of heritabilities and genetic correlations among GSM traits collected during two harvest seasons: standard and winter. Sizes and weights were highly heritable (0.41{\textpm}0.07 to 0.92{\textpm}0.09), and highly genetically correlated across traits and seasons (>=0.75{\textpm}0.07). Meat cover and gonad scores (measures of visual appeal) had lower heritabilities than did size and yield traits (0.08{\textpm}0.03-0.25{\textpm}0.05). Under standard conditions, meat cover had a high genetic correlation with gonad condition scores (0.85{\textpm}0.04). Under winter conditions the relationship between meat cover and gonad scores was negative (-0.52{\textpm}0.19). Substantial GxE was observed across seasons (meat cover: rg=-0.58{\textpm}0.16; gonad: rg=0.62{\textpm}0.11). Progress made from genetic selection to increase meat yield while controlling for the size may be slow, so selecting for traits related to visual appeal may be preferable. Given that production traits are genetically similar across harvest conditions, selection within standard conditions is likely to improve performance in both standard and winter harvests, thereby allowing for an extended harvest period. However, the genetic improvement of visual appeal of the mussels is likely to be influenced by target harvest season.}, issn = {1176-5283}, author = {Hess AS and Dodds KG and Roberts RD and King N and Symonds J and Clarke SM} } @article {3672, title = {Growth performance of crossbred dairy calves fed different milk allowances using an automatic feeding system}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {21-25}, address = {Lincoln}, abstract = {The impact of feeding different levels of milk replacer via automated feeders on intake and growth was assessed in calves. Heifer calves (Holstein {\texttimes} Jersey; n=198; 11{\textpm}4 days old) were randomly allocated to low-allowance (LA; n=67; calves were fed milk replacer at 10\% of initial live weight), high-allowance (HA; n=65; calves were fed milk replacer at 20\% of initial live weight), and ad-libitum (ADLIB; n=66; calves were given ad libitum access to milk replacer). Pelleted calf starter was provided ad libitum and daily individual intake of milk replacer and calf starter was measured via automated feeders. Calves were gradually weaned from 69{\textpm}2 days over 14 days. Average daily weight gain during pre-weaning was the highest (P<0.05) for ADLIB (0.69{\textpm}0.02 kg/ day), followed by HA (0.61{\textpm}0.02 kg/day) and LA (0.54{\textpm}0.02 kg/day) calves. Calf starter intake was the lowest (P<0.05) in ADLIB calves followed by HA and LA calves. The ADLIB calves had the lowest (P<0.05) calf starter intake during the week after milk weaning but it did not affect the live weight of calves. In conclusion, provision of more milk promoted pre-weaning growth, and restricted milk feeding to trigger solid feed intake failed to match that growth advantage.}, issn = {1176-5283}, author = {Groenendijk ME and Lowe K and Schreurs NM and Molenaar AJ and McCoard SA and Luo D and Khan MA} } @article {3672, title = {Heritability of longevity in New Zealand dairy goats}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {11-15}, address = {Lincoln}, abstract = {Longevity is a trait of economic importance in dairy goat farming. Actual longevity (AL) is defined as the number of days from birth to when the animal leaves the herd, whereas functional longevity (FL) is defined as AL adjusted for first lactation energycorrected milk yield (ECMY). This study reports the heritability (h2) for AL and FL in New Zealand dairy goats. Records of longevity from 12,108 does born between 1993 and 2011 were analysed with a model that included the fixed effects of herdyear (does born in the same herd and year) and covariates for the proportion of Alpine, Nubian, Toggenburg and heterosis, and the random effect of animal. The model for FL was the same as AL, but included ECMY as a covariate. Average AL was 1,891 (SD=832) days. Estimates of h2 were 0.07 for AL and FL. The estimated regression coefficient for ECMY on AL was 0.56 days/ litre. There were significant differences in longevity among herds, indicating that management and feeding are important factors affecting longevity. Further research is required to estimate genetic correlations with economically important traits.}, issn = {1176-5283}, author = {Scholtens MR and Lopez-villalobos N and Garrick DJ and Blair HT} } @article {3672, title = {The impact of different management systems on behaviour and milk production of dairy ewes in different stages of lactation; a case study}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {116-121}, address = {Lincoln}, abstract = {Comparisons of New Zealand dairy sheep farm systems are currently lacking. The aim of this preliminary study was to evaluate the effects of different management systems on the behaviour and milk production of East Friesian cross-bred sheep at different stages of lactation. Two study groups were evaluated. In study group 1, a mob of 479 mixed-age, mid-lactation ewes were housed 24 h/day, and a separate mob of 473 mixed-age, mid-lactation ewes were managed in a hybrid system (housed between morning and afternoon milkings; grazed lucerne overnight). Both received a total mixed ration (TMR) indoors. In study group 2, a mob of 604 mixed-age, late-lactation ewes grazed pasture 24 h/day, and a separate mob of 452 mixed-age late-lactation ewes were in a hybrid system, grazing pasture overnight. For both study groups, individual milk yield, walking distance, lying time, live weight (LW), and body condition score (BCS) were recorded. All sheep gained BCS and LW except fully grazed late-lactation ewes. For study group 1, fully housed ewes in mid-lactation lay down less during the day, but more overnight compared to those in the hybrid system, likely due to the latter grazing overnight. Lying bout times were similar between groups, while milk yield was 29\% less in housed ewes compared to the hybrid ewes. For study group 2, grazing ewes in late-lactation lay down more, had longer lying bouts, and walked further daily than those in the hybrid system, but both late-lactation treatment groups had similar milk yields. In summary, the hybrid management system seems to improve milk yield in mid-lactation compared to the fully housed system, whereas there was no difference between the hybrid and fully grazed systems in late-lactation. Lying behaviour and walking distances (group 2 only) differed among different systems, however, it is unclear what this means in terms of animal welfare, and warrants further investigation.}, issn = {1176-5283}, author = {Bliss AE and Chylinski C and Luo D and Sch{\"u}tz KE and Lowe K and Peterson SW and Stevens D and MacDonald T and McCoard SA} } @article {3672, title = {In sacco digestion kinetics of plantain and ryegrass-white clover harvested in the morning and afternoon}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {34-39}, address = {Lincoln}, issn = {1176-5283}, author = {Box LA and Edwards GR and Bryant RH} } @article {3672, title = {The influence of dam live weight on the carcass weight of rising-yearling farmed red deer and wapiti crossbreds}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {62-65}, address = {Lincoln}, abstract = {The New Zealand Deer Industry set productivity improvement targets in 2012 for the following 10 years, many related to breeding hinds. Increasing progeny carcass weight was the key trait of interest outside of hind reproductive performance. In this study, the productive output of dams was investigated. Data were collected from red deer and wapiti crossbred progeny (n=2289) born and raised on three farms over five years (2011-2015) from red deer dams (n=1353), mated to 51 red or wapiti stags. Data were analysed using a restricted-maximum likelihood (REML) mixed-model approach to produce predictive models of dam production outputs across a range of dam live weight. The most influential fixed effect in the model was sex, followed by dam mature weight. Predictions were made for progeny carcass weight of male red deer, and of male and female wapiti crossbreds at a mean slaughter age of 348 days from dam mature live weight. For the PIP target 115 kg red deer dam, the goal of a 64 kg progeny carcass was not achieved in this population, with a 115kg red deer dam predicted to produce 58.0, 63.0 and 54.5 (SEM 0.7, 0.9 and 0.9) kg carcasses for red male, wapiti crossbred male and females respectively. Industry should increase selection for hind productive efficiency.}, issn = {1176-5283}, author = {Ward JF and Meenken ED} } @article {3672, title = {Investigation into udder characteristics, mastitis and milk production in crossbred sheep}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {82-87}, address = {Lincoln}, abstract = {Associations between udder characteristics, milk yield, milk somatic cell counts (SCC) and prevalence of mastitis were evaluated in 121 twin-suckled crossbred non-dairy ewes at four, eight and twelve weeks after parturition. Overall, milk production decreased with time, being 1.09 {\textpm} 0.04 litres per four hours at week four of lactation, 0.68 {\textpm} 0.02 litres at week eight and 0.48 {\textpm} 0.01 litres at week twelve with corresponding mean SCC of 0.32 x 106 cells mL-1, 0.39 x 106 cells mL-1 and 0.28 x 106 cells mL-1, respectively. Incidence of mastitis was 12.7\%, 9.8\% and 8.9\% for weeks 4, 8 and 12, respectively. Of the 20 individuals that displayed SCC indicative of mastitis, only 5 had elevated SCC at more than one sampling time. No consistent association was observed between SCC and visual scores for udder depth, udder distention, degree of separation or teat placement (P>0.05 for all). Milk volume and weight of lamb was greater for ewes with an udder depth of 3 compared with 4 with no other associations evident (P>0.05). Overall, the incidence of subclinical mastitis was low but present in this flock with the udder characteristics assessed here providing poor indicators of either mastitis or milk production.}, issn = {1176-5283}, author = {Yusuf OM and Logan CM and Ridler AL and Greer AW} } @article {3672, title = {Invited opinion paper: Ways food systems undermine choice to the detriment of herbivores and humans}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {204-211}, address = {Lincoln}, abstract = {Landscapes with rich arrays of forages and foodscapes with rich assortments of wholesome foods are nutrition centres and pharmacies for herbivores and humans. Whether herbivore or human, health ensues when cultures learn to combine biochemically rich foods into meals that nourish and satiate. Biochemically rich diets include not only energy, protein, minerals, and vitamins, but also a host of other compounds{\textemdash}such as phenolics, terpenes, and alkaloids{\textemdash}with nutritional, prophylactic, and therapeutic benefits. We discuss some not-so-obvious ways food systems undermine biochemically rich alternatives and choices to the detriment of herbivores and humans. We also consider how food systems can enable individuality in form (morphology), function (physiology), and behavior by providing biochemically rich foods. We conclude by discussing how providing a variety of wholesome foods{\textemdash} and letting the wisdom of the body guide food selection{\textemdash}can enhance the health and well-being of herbivores and humans.}, issn = {1176-5283}, author = {Provenza FD and Gregorini P} } @article {3672, title = {Is it possible to produce good quality meat from Holstein-Friesian bulls?}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {194-199}, address = {Lincoln}, abstract = {There is potential to increase the value of meat from Holstein-Friesian bulls by increasing the proportion of carcasses that are of suitable quality to be eligible for primal cuts sold in high-value markets. The objective of this study was to explore relationships between carcass and meat-quality traits from Holstein-Friesian bulls between 21-38 months of age, slaughtered on different occasions. Meat samples of M. longissimus lumborum were collected at slaughter and chill-aged at -1.5{\textordmasculine}C for seven days. The means ({\textpm}s.d.) were: carcass weight 313{\textpm}29 kg (n=256), dressing-out 54.7{\textpm}2.6\% (n=256), ultimate pH 5.9{\textpm}0.38 (n=221), shear force 11.34{\textpm}4.93 kgF (n=221), cook loss 28.4{\textpm}5.4\% (n=220) and colour indexes (n=159) L* (lightness) 36.06{\textpm}2.96, a* (redness) 12.38{\textpm}4.04 and b* (yellowness) 8.74{\textpm}2.24. A total of 80 samples (36\%) were found to be both of acceptable tenderness (below 10.9 kgF) and pH less than 5.8. Alleviating meat pH issues is required to ensure high-quality meat from bulls that is suitable for high-value primal cuts.}, issn = {1176-5283}, author = {Martin NP and Schreurs NM and Morris ST and McDade JL and Craigie CR and Hickson RE} } @article {3672, title = {Lamb castration and tailing practices in New Zealand: results of a questionnaire}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {96-99}, address = {Lincoln}, abstract = {There is a large body of literature that has examined the impacts of castration and tailing on lamb behaviour, stress response, pain and productivity (Fisher et al. 2010; Kent et al. 1993; Mellor et al. 2002; Mellor \& Stafford 2000). Recently, Kerslake et al. (2015) investigated lamb tail docking, residual tail length and the reasons behind farmers{\textquoteright} choice to dock. There is little information available, however, regarding castration methods and reasons for the choice of leaving lambs entire, castrated or short-scrotumed. A printed questionnaire was distributed to ~12,000 farmers on the Beef + Lamb New Zealand database. The questionnaire contained 30 questions on aspects of management of flystrike, louse control, tailing and castration. Information was sought regarding percentage of lambs tail docked, method used to remove tails, reason for the tailing decision, proportions of male lambs left entire or castrated or short scrotumed, the method used to castrate or short-scrotum, and the reason for choice of male lamb type. A total of 1253 (10\%) of questionnaires were returned. Of the farmers that responded, the most commonly used tailing method was a hot iron (61\%), followed by rubber rings (31.4\%). Lamb growth was the primary reason that farmers gave for leaving lambs entire, and to a lesser degree short-scrotum. The reason behind the decision to castrate was most commonly related to lamb behaviour, however, a number of reasons had similar frequencies (lambs stay cleaner, infertility and meat quality).}, issn = {1176-5283}, author = {Corner-Thomas RA and Ferguson MB and Kenyon PR and Stafford KJ and Pomroy WE} } @article {3672, title = {MATN3 underlies a QTL for stature in cattle}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {51-55}, address = {Lincoln}, abstract = {Live weight (LWT) in dairy cattle is associated with milk production efficiency, and also has a high genetic correlation with stature. To identify genetic regions impacting stature and LWT, we conducted a genome-wide association study using 65,500 mixed-breed NZ dairy cattle and 16,243,015 imputed genotypes. We identified a quantitative trait locus (QTL) at BTA11:78- 79Mbp for stature that was significant at a genome-wide level (β=3.98mm {\textpm} 0.56; P=1.6{\texttimes}10-12) but not significant for LWT (β=1.253 {\textpm} 0.393 kg; P=1.4{\texttimes}10-3). Ensembl{\textquoteright}s Variant Effect Predictor was used to search for coding variants to attempt to identify a candidate causative gene for this QTL, and gene expression from RNA sequence data representing 373 cows were analysed for 16 genes and 3,640 markers to highlight expression QTL (eQTL) in this region. The gene with the most significant eQTL was MATN3 (ENSBTAG00000020893; P=2.5{\texttimes}10-38), encoding a protein which is involved in bone development. The correlation between variant effects (-log p-values) was calculated for the stature QTL and MATN3 eQTL (r=0.584), with the same variant (rs475277351) most significant for both QTL. This suggests a common genetic signal underlying both QTL, supporting the hypothesis that the MATN3 gene underlies the stature QTL.}, issn = {1176-5283}, author = {Lopdell TJ and Littlejohn MD} } @article {3672, title = {Metabolic profiles of non-lactating, pregnant heifers during transitioning from kale to swedes in Southland, New Zealand}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {26-30}, address = {Lincoln}, abstract = {During winter 2014, a study was conducted in non-lactating pregnant dairy heifers to monitor changes in liver enzymes during a six-week period following a diet change from kale to swedes. Blood samples were collected from 20 cows on Days 0, 4, 7, 14, 28, and 42 after transitioning. Changes were recorded for most blood metabolites, in response to the change from kale to swedes, indicating potential liver inflammation or hepatic cell stress damage. On days four and seven, 6 and 8\% of animals had lower than normal concentrations of AST, respectively. Elevated concentrations of GGT and GLDH, relative to Day 0, were recorded on Day 7 and 14 in individual cows. NEFA concentrations peaked on Day 4, possibly indicating a decrease in feed intake during the initial transitioning process. Up to 40 percent of the herd exhibited metabolic changes during the transition period. Although the concentration of some metabolites were above the normal range for individual animals between days 4 and 14, they had decreased to within the normal range by day 28, indicating that cows had become adapted to the new diet. Results suggest that, even with good practice, individual animals within a herd are at risk of liver stress when transitioning onto swedes.}, issn = {1176-5283}, author = {Dalley DE and Sheahan A} } @article {3672, title = {Milk production and milk fatty acid composition of grazing dairy cows supplemented with fodder beet}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {6-10}, address = {Lincoln}, abstract = {A study was conducted to evaluate the effect of supplementing a perennial ryegrass-based diet with fodder beet on milk production and milk fatty acid (FA) composition, of dairy cows in early lactation. Sixty Friesian {\texttimes} Jersey cows, were blocked into six groups of 10 cows, and groups randomly allocated to three replicates fed either 18 kg DM/day of ryegrass herbage (H), or 14.4 kg DM/ day of ryegrass herbage + 4 kg DM of harvested FB bulbs (FBB). Dry matter intake (DMI) was similar between H and FBB (15.0{\textpm}0.77 and 14.2{\textpm}0.48 kg DM/day respectively). Although milk yield tended to be greater for H than FBB (20.0 and 18.9 kg/ day respectively; P=0.09); milk solids production was not affected by treatment (P=0.89). Supplementation with FBB increased the saturated (80.6 versus 73.2{\textpm}0.39 g/100g FA; P<0.001) and medium chain milk FA (66.7 versus 56.2{\textpm}0.783; P<0.001) content, compared with H. Under the conditions of the present study, our results suggest that, supplementing grazing dairy cows with FBB in early lactation, may not improve milk production and increases the saturated FA content of milk.}, issn = {1176-5283}, author = {Fleming AE and Edwards GR and Bryant RH and Dalley DE and Gregorini P} } @article {3672, title = {Pasture use and management in commercial equine production systems}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {40-44}, address = {Lincoln}, abstract = {Despite a perceived reliance of horses on pasture there are limited data on efficiency of pasture utilisation in equine production systems. The unique equine behaviour characteristics of highly selective browsing, combined with faecal avoidance, provide distinct grazing management challenges compared to those of ruminants. Data reported here show that faecal avoidance results in the establishment of lawns and roughs (overgrazed and poorly grazed areas, respectively) with it estimated that only 70\% of the total pasture DM/ha on offer is utilised by horses. During spring, lawns contained more grass (74\% vs 53\%) and clover (5\% vs 3\%) and less weeds (2\% vs. 11\%) and dead matter (19\% vs. 33\%) than did roughs. Weanlings will start to graze roughs once the lawns are <1500 kg DM/ha. Roughs, however, will not be grazed within 1 m of a faecal pile. This translates to a lower pasture utilisation rate in weanlings and the biased grazing pattern means estimates of total pasture DM over-estimate the true available pasture DM. The relative proportion of pasture in lawns and roughs changes during grazing and prevents the application of a simple correction factor to estimate available DM. Broodmares had greater rates of pasture utilisation and less bias for consumption of pasture in areas of roughs than did weanlings.}, issn = {1176-5283}, author = {Rogers CW and Gee EK and Back PJ and van Zon S and Hirst RL and Pomroy WE} } @article {3672, title = {Phenotypic correlations of milk urea and the efficiency of crude protein utilization with milk yield traits and cow performance in two contrasting dairy systems in New Zealand}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {76-81}, address = {Lincoln}, abstract = {The objectives of the present study were to investigate phenotypic correlations of milk urea (MU) and efficiency of crude protein utilization (ECPU) with milk production and cow parameters in two contrasting herds. Between July 2016 and May 2017, 210 cows were milked twice daily with high supplementary feed inclusion (HS) and 258 cows were milked once daily with low supplementary feed inclusion (LS). In early, mid and late lactation, milk samples were collected to measure MU. At every herdtest date, ECPU was calculated as protein yield (PY) divided by crude protein intake (CPI); this last variable derived from intake estimations of metabolizable energy requirements. Positive correlations between milk yield (MY) and both dry matter intake (DMI) and CPI were observed in LS and HS. The ECPU only correlated positively with MY traits in LS, and there was no correlation of CPI with MU in either herd. A moderate negative correlation of ECPU with live weight (LW) was observed in both herds, but it was stronger in LS. By suppressing MY due to the reduced milking frequency of cows fed LS, these cows gained LW, had higher body condition score and CPI, and lower PY, reducing the ECPU. No correlation between ECPU and MU was detected.}, issn = {1176-5283}, author = {CorreaLuna M and Lopez-villalobos N and AlmeidaJr GA and Donaghy DJ and Kemp PD} } @article {3672, title = {Plantain: It is not only the dietary content, but also how we graze it{\textellipsis}}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {151-156}, address = {Lincoln}, abstract = {A mechanistic and dynamic model of a grazing ruminant, MINDY, was used to explore the effect of both the proportion dietary inclusion of plantain (PL) and its grazing management, compared with ryegrass (RG), on urinary N (UN) excretion of dairy cows. The treatment tested were: 1) frequency of allocation and 2) dietary proportion of PL. Frequency of allocation was set by stripgrazing (24 hrs. pasture breaks) PL or RG monocultures for 1, 5 or 10 consecutive days, allocated either after the morning (AM) or afternoon (PM) milking. The proportion of dietary PL was set by offering either 25 or 50\% of the diet as PL monocultures allocated either AM or PM. MINDY had greater intake of PL-containing diets than RG alone, resulting in increased N intake. However, with the exception of the {\textquoteleft}frequency{\textquoteright} treatments, daily urinary N excretion (UN) was reduced by including PL compared with RG alone. Plantain monocultures led to similar or lower urine volume compared with RG. Grazing RG and PL every 1 or 5 days increased urine volume, frequency and UN compared with RG or continuous PL. Offering PL or RG in the AM compared with PM reduced UN but reduced milk yield. This modelling exercise suggests that including PL in cattle{\textquoteright}s diet reduces UN and UN concentration, and that the frequency and timing of its allocation help to reduce environmental impact further while maintaining or increasing MS.}, issn = {1176-5283}, author = {Gregorini P and Bryant RH and Beck MR and Edwards GR} } @article {3672, title = {PRESIDENTS ADDRESS 2018: Moving the cheese}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {212-213}, address = {Lincoln}, issn = {1176-5283}, author = {Schreurs NM} } @article {3672, title = {Reproductive performance of pregnant red deer hinds fed swede forage-crops in winter}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {165-169}, address = {Lincoln}, abstract = {Reproductive wastage is a significant cause of productivity loss in New Zealand deer herds. This study investigated the impact on reproductive performance of red deer hinds fed swedes over winter. Forty rising-two-year-old and 40 mixed-aged pregnant hinds were drafted into two groups each and grazed for 100 days over winter on either a swede forage crop or pasture. Hinds were blood sampled regularly, weighed fortnightly and pregnancy scanned monthly. Blood samples were analysed for blood urea nitrogen and indicators of liver damage. Swede forage crops were sampled for nutrient and glucosinolate concentrations. No significant differences in hind foetal loss were found between the two wintering systems or two age classes. Swede glucosinolate concentrations levels were above thresholds considered dangerous for animal consumption but no liver damage was observed. Blood urea nitrogen levels did not differ between the swede- and pasture-fed hind groups until day 80, which was 10 days after the swede groups were transferred to another swede crop, when blood urea nitrogen levels were significantly lower in the swede groups. This research indicated that grazing on swedes did not influence reproductive wastage in this instance. However, the effect of low protein intake over an extended period during pregnancy needs to be investigated further.}, issn = {1176-5283}, author = {Thompson BR and Stevens DR and Petit MA and Asher GW} } @article {3672, title = {The role of curding and non-curding calf milk replacers in NZ calf-rearing systems}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {157-160}, address = {Lincoln}, abstract = {Calf milk replacers (CMRs) are typically formulated from a range of lower-value milk products and may have reduced curding ability when casein proteins are absent or denatured. Whilst there are industry claims that vealer calves in Europe can be reared on such CMRs, there is no NZ data to substantiate these claims. In Experiment One, 240 calves were reared on three milk replacers. Diet A was a curding CMR based on whole-milk powder and skim-milk powder. Diet B was a non-curding CMR based on whey and vegetable fat. Diet C was a non-curding CMR based on whey, soy and vegetable fat. A salmonella challenge occurred in the rearing facility during the first two weeks of rearing. Calves on Diet A suffered a much lower incidence of sickness than those on Diets B and C (15\% vs 34\% vs 61\%) respectively. Mortality was also lower (1.25\% vs 5\% vs 5\% respectively). In Experiment Two, 90 calves were fed on the same diets from four days to 13 weeks of age. There were no effects of diet on disease or mortality. Calves on Diet A, B and C had growth rates to 13 weeks of 0.63, 0.60 and 0.53 kg/day, respectively. In conclusion, rearers need to be aware that there a risk when feeding non-curding milk replacers to young calves, particularly when timely weight targets need to be achieved.}, issn = {1176-5283}, author = {Thomson BC and Muir PD and Smith NB and Nieuwenhuis A} } @article {3672, title = {The role of pasture and silage in supporting milk production in dairy goats in New Zealand {\textendash} a case study approach}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {111-115}, address = {Lincoln}, abstract = {Milk production on dairy goat farms in New Zealand is highly variable: the average is around 75 kg total solids/doe/year with a range of 39-135 kg total solids/doe/year. The source of variability in production is unclear but is potentially due in part to the diversity in forage-supply systems used by dairy goat farmers. The majority of milking herds that supply the Dairy Goat Cooperative are housed indoors for health and production reasons and are fed a mix of freshly-cut pasture and silage in a cutand- carry system with the addition of concentrates and other supplemental feeds when required. To determine how pasture and silage were used in dairy goat feeding systems, four farms were enrolled in a case study approach. Estimates of the quantity of pasture and silage fed were made and samples were taken and analysed for quality periodically over a one-year period. Results showed that pasture quality generally followed the expected seasonal curve for the Waikato. Pasture quality declined from about 12.5 MJ ME/kg DM in early spring to 11 MJ ME/kg DM or less in December and was largely unavailable from March. At this time, silage becomes a much more important component of the feed-supply system. The quality of the silage was, however, variable with dry matter content, metabolisable energy and crude protein (CP) levels sometimes outside recommended limits. Total diets were deficient in nutrients at some times on some farms, especially with respect to protein. A comparison of calculated feed requirements with what was actually fed showed that protein was deficient in six of the twelve sample periods, by up to 211 g of CP/doe/day. These deficits were associated with lower milk production. This study highlighted the potential for higher milk production from maintaining both pasture and silage quality.}, issn = {1176-5283}, author = {King W and Burggraaf V and Mapp N and Ganche E and Hutchinson K and Johnson M} } @article {3672, title = {Simulating the intake and nitrogen excretion from cows grazing forages fertilised with increasing rates of nitrogen}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {141-145}, address = {Lincoln}, abstract = {The dry matter intake (DMI), production, and urinary nitrogen (N) excretion of dairy cows grazing forage grown under increasing N fertiliser rates were explored using a mechanistic model of a grazing ruminant. The MINDY cow model was initialised to represent a multiparous Holstein-Friesian dairy cow in late lactation (age 3.5 years, 212 days in milk). Simulated cows were offered a common allowance (30 kg DM/cow/d) of chicory, plantain, lucerne, or perennial ryegrass, fertilised at rates of 0, 100, 200, 350 and 500 kg N/ha/y (0N, 100N etc.) for 20 days in March. Forage physical and chemical composition data were obtained from a Waikato experimental field site. When N rate increased from 0{\textendash}500N, predicted DMI of cows grazing plantain and ryegrass increased by 5.2 and 2.7 kg DM/cow/day (43 and 20\% increase), respectively, facilitated by increased sward height and mass, and reduced herbage strength. Predicted DMI of cows grazing chicory peaked at 200N and, for cows grazing lucerne, declined with N fertilisation. Intake of highly fertilised (>200N) chicory and lucerne diets were potentially affected by high herbage soluble N content resulting in high predicted rumen ammonia concentrations (>18 mmol/L), reducing incentive for grazing. While predicted milk production from cows grazing chicory, plantain and ryegrass increased, the efficiency of dietary N used for milk production declined, with increasing N applied. Increasing N rate also increased predicted urine N concentration, and urinary N excretion from simulated cows fed chicory, plantain, and ryegrass. This study suggests that N fertiliser rates of 200N for chicory, plantain and ryegrass provides a balance between cow production and N excretion.}, issn = {1176-5283}, author = {Minnee EMK and Bryant RH and Chapman DF and Gregorini P} } @article {3672, title = {Supplementation of ewes on pasture to provide an epidemiological benefit for gastrointestinal parasitism}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {45-50}, address = {Lincoln}, abstract = {The potential epidemiological benefit of reducing the peri-parturient relaxation in immunity to gastro-intestinal nematode parasites through supplementing twin-bearing ewes during the first four weeks of lactation was evaluated in a replicated farmlet study. In two sequential years, ewes either grazed pasture alone or grazed pasture while supplemented with 0.5 kgDM/d of a high-protein pellet. Supplementation did not affect ewe live weight or body condition score or weight of lamb weaned per ewe (P>0.05). Ewe faecal egg counts (FEC) showed a time x supplementation interaction (P<0.05), being reduced by 50\% from week six of lactation in both years, although this only resulted in transient and inconsistent reductions in pasture larval contamination. After weaning, there was no consistent parasitological benefit to lambs grazing areas where ewes had been supplemented that were reflected in either pasture larvae concentrations, lamb FEC, the requirement for anthelmintic treatment or lamb growth rate (P>0.05 for all). Despite supplementation of ewes during the first four weeks of lactation successfully reducing ewe faecal egg count by 50\%, this was not sufficient to provide a measureable and consistent epidemiological benefit to the lambs.}, issn = {1176-5283}, author = {Tambunan RD and Logan CM and Bywater AC and Greer AW} } @article {3672, title = {To train or not to train heifers to the milking parlour prior to calving? That is the question for New Zealand dairy farmers}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {177-182}, address = {Lincoln}, abstract = {A survey was conducted to identify: 1) the number of dairy farms that train their heifers to the milking parlour prior to calving, 2) the reasons why farmers chose to train or not and 3) what training methods farmers use. The questionnaire was sent to 250 randomly selected dairy farmers within New Zealand. Of the 93 respondents, 52\% trained their heifers to the milking parlour prior to calving and 48\% did not. Of those that trained, 79\% trained to reduce stress levels, 13\% to increase milk production and 19\% to reduce risk of injury to animal/farmer. Conversely, of the farmers that did not train their heifers to the milking parlour prior to calving, 56\% reported that {\textquotedblleft}cows teach the heifers{\textquotedblright}, 24\% reported that they were too busy and 31\% indicated that training did not work. The main methods of training included walking heifers through the milking parlour, holding heifers in the parlour and exposing them to people. The results from this survey provide interesting information regarding the motivation of farmers to train (or not train) heifers to the milking parlour prior to calving and what training methods are used. Information gained from this survey can inform the direction of future research so that science-based farmer friendly recommendations for heifer training can be developed.}, issn = {1176-5283}, author = {Sutherland M and White T and Chen K and Hempstead M and Huddart F} } @article {3672, title = {Whole-farm modelling using different grazing-management strategies with diverse pastures within an irrigated dairy-farm system}, journal = {New Zealand Journal of Animal Science and Production}, volume = {78}, year = {2018}, month = {07/2018}, pages = {1-5}, address = {Lincoln}, abstract = {The objective of this study was to assess the effect of diverse pasture mixtures and grazing management on profitability of Canterbury dairy farms using a commercial modelling tool, Farmax Dairy Pro. Two years of pasture growth and quality data were obtained from irrigated plots sown with a pasture mixture consisting of perennial ryegrass, white clover, red clover, chicory and plantain (diverse) or the same pasture mixture plus Italian ryegrass (diverse-Italian). Pastures were subjected to one of three grazing management regimes: (1) conventional grazing (grazed to a compressed height of 3.5 cm all year); (2) spring lenient grazing; and (3) autumn lenient grazing. The data were fitted to a base model farm (average of North Canterbury region) using Farmax Dairy Pro to produce six different farm scenarios. Farm scenarios were ranked and compared by profit expressed as earnings before tax. Pastures managed by autumn lenient grazing resulted in the lowest DM production, more supplement purchased, and hence, lowest profit compared with conventional or spring lenient grazing management. The diverse pasture managed by spring lenient grazing resulted in the greatest profit ($2,658/ha) compared with other scenarios (average $2,261/ha). This greater profit was driven by greater annual DM production per hectare and, hence, less supplement purchased. When diverse pasture is considered, spring lenient grazing is a potential management option for irrigated Canterbury dairy farm systems to increase DM production and thereby profitability.}, issn = {1176-5283}, author = {Cun, GS and Al-marashdeh O and Edwards GR} } @conference {3672, title = {Abstracts from the Sheep Milk NZ Conference - Awapuni Function Centre March 3-15 2017}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {237-245}, address = {Rotorua}, issn = {1176-5283}, author = {Anonymous} } @conference {3672, title = {BRIEF COMMUNICATION: An investigation of mastitis in a hill-country sheep flock}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {114-116}, address = {Rotorua}, abstract = {The prevalence of mastitis in New Zealand ewes has not been studied for over 40 years. Quinlivan (1968a,b) examined 19427 Romney ewes in the lower North Island and detected mastitis in 0.6-1.7\%. Clarke (1972) surveyed 118249 ewes in the lower South Island and found the incidence of mastitis was 0.6-0.7\%. Skyrme (1970) reported the occurrence of {\textquotedblleft}hard udders{\textquotedblright} and implicated them in lamb deaths. Perhaps because of such reports of low incidence, little research into sheep mastitis has been done in New Zealand...}, issn = {1176-5283}, author = {Peterson SW and Nieper B and Collett MG and Grinberg A} } @conference {3672, title = {BRIEF COMMUNICATION: Assessing the current value of milk, meat and fibre products from the goat industry in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {173-176}, address = {Rotorua}, abstract = {Goats have a historical record of being productive and valuable to families and communities (Aziz 2010). Small ruminants, which include goats, still have an {\textquoteleft}unfulfilled{\textquoteright} potential despite the numbers of animals farmed and their distribution around the world (Anaeto et al. 2010). Pollot and Wilson (2009) concluded that goats deserve greater attention due to their capacity for producing food. A similar study in New Zealand (Sheppard \& O{\textquoteright}Donnell 1979), described the uses of goats for meat, skins, milk and mohair and concluded that the goat was valuable, but that the production potential was largely unfulfilled. A recent New Zealand study (Ministry of Agriculture and Forestry 2009) concluded that food-consumption patterns are changing in New Zealand, and globally demand for more diversified products provided an opportunity for goat meat. The objective of this study was to determine the current value of domestic and exported New Zealand goat products and to explore possible future products and their target markets. Many of these product values are gathered from retailers, personal communications and individual producers. This research is an attempt to bring together information that has not yet been gathered to present a current value of the goat in New Zealand...}, issn = {1176-5283}, author = {Lopez-Lozano SR and Scholtens MR and Smith RMC and Lopez-Villalobos N and Burt D and Harper L and Thomas DG and Carr AJ and Gray DI and Tozer P and Schreurs NM} } @conference {3672, title = {BRIEF COMMUNICATION: Effect of disbudding on pain sensitivity and weight-gain of dairy goat kids}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {159-160}, address = {Rotorua}, abstract = {Cautery disbudding is a painful husbandry procedure commonly carried out on dairy cow and goat farms worldwide. Disbudding can cause third-degree burns, subcutaneous tissue damage, inflammation, bacterial infection and in some cases death (Sanford 1989, Thompson et al. 2005, Wright et al. 1983). Physiological (e.g., cortisol, β-endorphins) and behavioural (e.g., head shaking) changes indicative of pain have been described in response to cautery disbudding in kids (Alvarez et al. 2015, Greenwood \& Shutt 1990, Ingvast-Larsson et al. 2011), but still little is known regarding the acute and long-term effects of cautery disbudding on goat kid welfare. Therefore, the aim of this study was to evaluate the effects of cautery disbudding on the acute pain response and weight-gain in goat kids. This study was part of a larger project investigating alternative methods of disbudding in goat kids. }, issn = {1176-5283}, author = {Hempstead MN and Stewart M and Sutherland MA} } @conference {3672, title = {BRIEF COMMUNICATION: Efficiency of crude protein utilization and milk urea nitrogen content in Friesian, Jersey and crossbred cows milked once daily}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {91-92}, address = {Rotorua}, abstract = {For the last two decades, the New Zealand dairy industry has intensified its milk production through the inclusion of feed supplements and the increasing use of nitrogen (N) fertilizer (Di \& Cameron 2000). Increasing N losses from these systems, mainly from urine (Li et al. 2012), can negatively impact the environment. Cow N utilization efficiency can play a role in mitigating this negative effect (Woodward et al. 2011)...}, issn = {1176-5283}, author = {CorreaLuna M and Lopez-Villalobos N and Donaghy DJ and Kemp PD and AlmeidaJr GA} } @conference {3672, title = {BRIEF COMMUNICATION: Feeding fodder beet to ewes in mid-to-late gestation: impact on lamb size, rectal temperature, and live weights from birth to weaning}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {34-36}, address = {Rotorua}, abstract = {New Zealand ruminant livestock production is largely pasture-based and aligned to seasonal pasture supply. Despite pasture providing a complete diet for grazing pregnant ewes when fed in sufficient quantities, there is a growing trend for farmers to use supplementary feeds to maintain production in times of feed shortages such as during winter, or to facilitate increased stocking rates (McCoard et al. 2015). Due to its high dry matter (DM) yield, and low cost per unit of feed, compared to other supplementary feeds (Gibbs et al. 2015), fodder beet (FB: Beta vulgaris) is a winter feed option. Fodder beet is characterised by its high sugar (energy rich) and low nitrogen (N) contents and although live weight (LWT) responses in finishing beef cattle fed FB have been measured (Gibbs et al. 2015), there is less knowledge on the nutrient-supply profile and performance of offspring when fed to pregnant animals. Knowledge of potential nutritional deficiencies, and the implications for the pregnant ewe and her offspring are essential in order to develop feeding recommendations for farmers. The objective of this study was to determine the effects of feeding FB vs. ryegrass dominant pasture (RG), to ewes in mid-to-late gestation, on offspring performance through the measurement of lamb size, rectal temperature and pre-weaning growth.}, issn = {1176-5283}, author = {Sandoval E and McCoard SA and Pacheco D and Lloyd-West C and Lees S and Hammond KJ} } @conference {3672, title = {BRIEF COMMUNICATION: High ultimate pH in short-scrotum male lambs processed during the breeding season}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {194-196}, address = {Rotorua}, abstract = {

Historically in New Zealand male lambs were castrated at the time of docking, however, there has been a move to instead create short-scrotum males, in which the testes are pushed within the body cavity and the scrotum removed (Johnson et al. 2007). This results in short- scrotum males, having similar physiological characteristics to entire ram lambs, except that they are almost always infertile and, therefore, do not present a management risk if they are accidently mixed with ewes or ewe lambs during the mating season. The normal ultimate pH of lamb meat is considered to be 5.50 to 5.80, with values above 5.8 and in particular above 6.0 considered high, and resulting in negative meat quality outcomes. There have been a number of studies that have investigated whether or not sex differences in the ultimate pH of lamb exist. The results are not always consistent with some studies reporting elevated ultimate pH in non-castrated male lambs (Johnson et al. 2005; Bain et al. 2009), whilst others have shown no differences (Kerslake et al. 2012; Schreurs 2013). In commercial farming operations there is a mix as to how farmers manage their lambs of different sexes during the finishing period prior to slaughter, and in many farming operations this period coincides with the on-set of the breeding season.

Given the most recent papers in this area have concluded that there is no sex-effect on ultimate pH, the purpose of this paper is to report on data collected from a trial that set out to invoke high ultimate pH (to investigate potential live-animal predictors of high ultimate pH) in short-scrotum male lambs during the breeding season.

}, issn = {1176-5283}, author = {PL Johnson and Stuart AD and Mackie A} } @conference {3672, title = {BRIEF COMMUNICATION: Hot years in history and facial eczema}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {107-109}, address = {Rotorua}, abstract = {

Facial Eczema (FE) is caused by grazing animals ingesting the toxin sporidesmin which is produced by spores of the fungus Pithomyces chartarum. In order for the fungus to sporulate, a series of weather and environmental events must occur, with warm, moist, humid conditions and leaf dead-matter at the pasture base required (Brook 1969). In New Zealand, the combination of required conditions has historically been confined to summer and autumn months in temperate parts of New Zealand as illustrated in a map published by di Menna et al. (2009).

There is a large body of research that concludes that the world is in a period of climate change, characterised by increasing temperatures and extreme weather events (Ministry of Environment NZ, 2008) with the temperature increases predicted to incrementally increase into the future. Using climate change predictions, modelling work reported by di Menna et al. (2009) and Dennis et al. (2014) demonstrated that into the future the geographical regions in New Zealand affected by FE would increase, as temperature increases would result in more areas achieving the minimum temperatures required for sporulation.

Through using published literature and media articles prior to 2016, the worst years for FE in New Zealands history were 1938 and 1999. Indeed the outbreak in 1938 was what led to the establishment of the Ruakura Research Centre (now AgResearch) in an attempt to understand the cause and control of the then-unknown disease that had resulted in photosensitivity, liver damage, production losses and death in affected animals (di Menna et al. 2009).

The purpose of this paper is to report on the FE outbreak of 2016 and to draw temperature parallels to the outbreaks of 1938 and 1999 using weather data from the Ruakura Weather Station.

}, issn = {1176-5283}, author = {PL Johnson and Cameron CA and Henderson HV and Cullen NG} } @conference {3672, title = {Brief Communication: In vitro fermentation characteristics of ryegrass-white clover sward containing differnt proportions of chicory}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {82-84}, address = {Rotorua}, abstract = {Chicory (Cichorum intybus) is a deep-rooted grazeable forage used to overcome production and nutritive value shortfalls of perennial ryegrass (Lolium perenne) and white clover (Trifolium repens) swards during summer drought periods in New Zealand (Waugh et al. 1998; Chapman et al. 2012). However, there is little and contrasting data on the proportion of chicory to be used in mixed swards to influence livestock production. For example, Golding et al. (2011) showed that feeding chicory in a mixed sward at 18{\textendash}40\% of total dry matter, increased lamb post-weaning liveweight gain (LWG) compared with a traditional ryegrass sward. On the other hand, Cheng et al. (2017) reported similar daily LWG for heifers offered a mixed sward of 50\% chicory and 50\% ryegrass-white clover or 100\% perennial ryegrass-white clover. These contrasting results justify more research on the chicory proportion in mixed swards and its effect on animal performance...}, issn = {1176-5283}, author = {Al-marashdeh O and Cheng L and Gregorini P and Edwards GR} } @conference {3672, title = {Brief Communication: Managing liveweight gain of Holstein-Friesian, Jersey and Holstein- Friesian-Jersey crossbred heifer calves}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {69-71}, address = {Rotorua}, abstract = {Large numbers of replacement heifers are not meeting target live weights in New Zealand (McNaughton \& Lopdell 2012; Handcock et al. 2016) which has implications for future milk production, fertility and subsequent longevity in the herd (Van Amburgh \& Tikofsky 2001; McNaughton \& Lopdell 2013). Undergrown heifers can lead to an overall decline in a herd{\textquoteright}s reproductive performance and milk production (McNaughton \& Lopdell 2012). McNaughton and Lopdell (2013) reported that for every 1\% increase in the percentage of live weight attained, heifers produced approximately 23 litres of extra milk during their first two lactations. As such, heifer growth, particularly post-weaning growth, has been identified as an area requiring greater attention from farmers to improve cow performance. There are established breed liveweight targets as well as liveweight targets based on an individual animals genetic potential and the growth of individual animals and groups can be monitored using programmes such as Livestock Improvement Corporation{\textquoteright}s MINDA Weights{\texttrademark} herd-recording software. However, while growth targets are commonly used, in many cases, being {\textquoteleft}on-target{\textquoteright} is based on a mob average, resulting in a proportion of animals below target live weight....}, issn = {1176-5283}, author = {Back PJ and Hickson RE and Sneddon NW and Coleman LW and Laven RA} } @conference {3672, title = {BRIEF COMMUNICATION: Once-a-day milking with supplemented cows in Argentina}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {61-63}, address = {Rotorua}, abstract = {Dairy farming is an important activity in Argentina. The country produced over 11,000 million litres of milk in 2015 (Ministerio de Agroindustria 2015). Milk production is based on the utilisation of grazed lucerne pastures (Medicago sativa L), and the use of supplements such as silage, hay and concentrate feeds. Pasture comprises between 30\% and 50\% of the diet. Average milk production per cow is 5,900 kg/cow per year (equivalent to 401.2 kg of milk solids/cow per year; INTA 2015). Due to a favourable ratio between milk price and concentrate feeds price (average ratio milk to concentrate price over 1.5), dairy farmers in Argentina include great amounts of concentrate feeds in their systems. Over 95\% of dairy herds of Argentina are Holstein, and cows are milked twice a day (TAD) (FAO 2011). In the last decade, studies have been conducted, mainly in New Zealand, but also in Europe, to evaluate the effects of once-a-day (OAD) milking during the whole lactation (Stelwagen et al., 2013). Lifestyle benefits for farmers and employees and improvement in animal health and reproductive performance are the main motivations to choose OAD milking (Bewsell et al., 2008)...}, issn = {1176-5283}, author = {Lazzarini B and Peluffo L and Lopez-Villalobos N and Hendrikse L and Baudracco J} } @conference {3672, title = {BRIEF COMMUNICATION: Reduced reproductive outcomes in ewes susceptible to facial eczema}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {197-199}, address = {Rotorua}, abstract = {There are both clinical and sub-clinical effects on grazing ruminants that ingest the toxin sporidesmin produced by the fungus Pithomyces chartarum, with the clinical effects of the toxin giving rise to the colloquial name of the disease {\textquotedblleft}facial eczema{\textquotedblright}. The sub-clinical effects of Facial Eczema (FE) have been documented and impact on most aspects of production from fertility through to growth. Data used to estimate the effects of the sporidesmin ingestion have ranged from natural exposure to high levels of sporidesmin in the outbreak in 1981 (Moore et al. 1990) through to differences in genetic selection lines and in trials where animals are artificially dosed with sporidesmin (Morris et al. 1991). Whilst the size of the impact does vary between studies, their overall conclusions are consistent, with decreased ewe fertility observed. In all studies, how the animal has tolerated (or not) the sporidesmin that it has been exposed to, is estimated through measuring serum gamma-glutamyl transferase (GGT) levels which have been shown to be a strong indicator of liver damage, the body organ most directly affected by the toxin (Towers \& Stratton, 1978)...}, issn = {1176-5283}, author = {PL Johnson and Henderson HV and Proffit R and Cullen NG} } @conference {3672, title = {BRIEF COMMUNICATION: Relationship between measures of residual energy intake made on growing animals and adults}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {85-87}, address = {Rotorua}, abstract = {In New Zealand pasture-based sheep systems, young replacement ewe lambs and those lambs to be finished for slaughter, are often preferentially fed through summer, with ewes which have just weaned their lambs given secondary priority through until their pre-mating period. This is particularly the case in hill-country environments, in which an increasing proportion of the New Zealand ewe flock is farmed. Feed efficiency, defined as residual energy intake (REI), is a measure of whether or not an animal is eating more or less than expected for its live weight and growth rate. Of interest is whether or not animals described as efficient, or inefficient during their young growth phase, when on high-quality diets, continue to be so as an adult grazing sub-optimal feed during summer periods. There is limited comparable literature in sheep. The general finding of the beef cattle work is that the young and adult measures of REI are moderately phenotypically correlated and very highly genetically correlated, although in the most comprehensive study both the young and adults were fed the same medium-quality feed (Archer et al. 2002). In dairy cattle work, they have also found that calves divergent for REI during growth are also divergent for REI when lactating, although the size of the divergence was reduced (McDonald et al. 2014)...}, issn = {1176-5283}, author = {PL Johnson and Wing J and Knowler K} } @conference {3672, title = {BRIEF COMMUNICATION: The current state of the New Zealand goat industry}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {164-168}, address = {Rotorua}, abstract = {

Goat farming in New Zealand has a lower profile compared to dairy, sheep and beef systems. The goat industry is small in New Zealand (Stafford \& Prosser, 2016) and there has been limited consideration of the potential for the industry to expand (Shepard \& O{\textquoteright}Donnell, 1979). The environmental and commodity market constraints currently impacting pastoral systems in New Zealand provide an opportunity for the goat industry to have a greater economic contribution to New Zealand{\textquoteright}s agricultural production.

In New Zealand, goats are farmed for milk, meat and fibre production and also act as a mechanism for controlling excess pasture growth, enhancing clover in mixed pasture and controlling weeds (Batten, 2014). The aim of this paper was to present an overview of the goat industry to provide background knowledge for consideration when deciding the direction of the goat industries in New Zealand. As part of the overview, farmers, processors and industry bodies were contacted to obtain an estimate of the number and location of goats farmed in New Zealand. Although some of the sources of information for the goat industry are not perfect, this research is an attempt to bring together information that has not been consolidated in nearly 40 years (Shepard \& O{\textquoteright}Donnell, 1979) and was achieved as part of a three-part study with companion papers being produced (Lopez-Lozano et al. 2017; Smith et al. 2017). Information from this study were used in conjunction with the value of the goat industry (Lopez-Lozano et al. 2017) to project the potential of the New Zealand goat industry (Smith et al. 2017).

}, issn = {1176-5283}, author = {Scholtens MR and Smith RMC and Lopez-Lozano SR and Lopez-Villalobos N and Burt D and Harper L and Tuohy M and Thomas DG and Carr AJ and Gray DI and Tozer P and Schreurs NM} } @conference {3672, title = {BRIEF COMMUNICATION: The effect of arginine supplementation and milk allowance on small intestinal development in pre-weaning calves}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {88-90}, address = {Rotorua}, abstract = {The gastrointestinal tract is an organ system crucial in feed digestion, nutrient absorption and protection against external pathogens. In this respect, changes in the structure of the small intestine in pre-ruminant calves are particularly important because it is the primary site of digestion and absorption (Blum 2006). Understanding factors that influence intestinal development is essential to inform calf feeding practices to optimise growth performance and health. Increasing milk allowance increases calf growth, but suppresses solid feed intake before weaning and, therefore, delays rumen development (Khan et al. 2011). In comparison to the rumen, development of the small intestine has received little attention in calf nutrition (Steele et al. 2016) and the effect of increased milk intake on small intestine development in calves is largely unknown (Khan et al. 2016)....}, issn = {1176-5283}, author = {van Keulen P and Welboren AC and Kahn MA and Knol FW and Dijkstra J and McCoard SA} } @conference {3672, title = {BRIEF COMMUNICATION: The potential of the New Zealand goat industry}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {169-172}, address = {Rotorua}, abstract = {The New Zealand goat industry is evolving and there is potential for expansion of its export products. The production and value of the New Zealand goat industry has been explored previously when the industry was in its infancy (Sheppard \& O{\textquoteright}Donnell 1979), at a time when Mohair production was seen to be {\textquoteleft}the most profitable goat farming enterprise{\textquoteright}. Since then major expansion has occurred in the production and export of dairy-goat products, and the production of quality Boer goat meat is under consideration. In order for further progress to be made, knowledge of the current production levels and value of the goat industry, and its potential for expansion is required. Using information describing the current situation of the goat industry (Scholtens et al. 2017) and the value of the goat (Lopez-Lozano et al. 2017), a model was created to estimate the current and potential production and value of the New Zealand goat industry by 2025. }, issn = {1176-5283}, author = {Smith RMC and Scholtens MR and Lopez-Lozano SR and Lopez-Villalobos N and Burt D and Harper L and Thomas D and Carr A and Gray D and Tozer P and Schreurs NM} } @conference {3672, title = {A brief study on the treatment and attitudes to rams on commercial NZ farms}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {125-128}, address = {Rotorua}, abstract = {A study was undertaken to better understand the care and attitudes towards rams on NZ commercial farms. Farms (n=22) were surveyed in Otago and South Canterbury giving indicative data on the treatment and attitudes that commercial farmers have towards rams. On average (SD; Range) the number of ewes put to each ram was, for maternal and terminal sires respectively, 92 (21; 56-143) and 84 (20; 50-100). The reported difference between when rams were put to ewes and when lambs were weaned was 319 days (51; 199-359). Rams were typically put to ewes in April and early May, and weaned as early as November. Visual assessment was most commonly used to assess rams for purchase, with most farmers considering visual attributes and then figures, such as breeding values, to choose rams. The average mortality of rams was reported as 5\% (7\%; 0-28\%). The average culling of maternal and terminal sires over the year was respectively 26 and 29\%. Annual health checks by a vet were reported for 45\% of the farms. A most common reason for checking was for Brucella ovis testing. This research will provide information to guide further studies on commercial sheep farms.}, issn = {1176-5283}, author = {Lee M and Robertson D} } @conference {3672, title = {Calf and heifer development and the onset of puberty in dairy cows with divergent genetic merit for fertility}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {205-210}, address = {Rotorua}, abstract = {A research herd with divergent genetic merit for fertility was established to better understand the underlying drivers of fertility in dairy cattle. This paper describes the establishment of this herd, heifer growth and development, and the effect of divergence in fertility breeding value (FBV) on the timing of puberty. The average FBV of the high and low fertility groups of heifers was +5.6 and -4.6, respectively. The heifers were weighed fortnightly, with body condition score (BCS) and stature recorded at six, nine, 12 and 15 months of age. Weight and age at puberty were defined as the first day when plasma progesterone was >1 ng/ml in two of three consecutive once weekly samples. There was no effect of FBV on live weight (LWT), BCS, nor stature by age as the heifers matured. High-fertility heifers attained puberty at a lighter LWT (271 vs. 296 kg; SED 4.3 kg), an earlier age (358 vs. 379 days; SED 6.0 days) and a lower proportion of estimated mature LWT (51 vs. 55\%; SED 0.7\%), compared with Low-fertility heifers. Therefore, the premise that high genetic merit for fertility is positively associated with reaching puberty earlier is supported. Further work is required to support and assess the value of incorporating a puberty trait into the FBV.}, issn = {1176-5283}, author = {Meier S and Fisher B and Eketone K and McNaughton LR and Amer PR and Beatson P and Bryant JR and Dodds KG and Spelman R and Roche JR and Burke CR} } @conference {3672, title = {Can Raman spectroscopy predict beef meat and eating quality traits?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {181-184}, address = {Rotorua}, abstract = {Quality assurance and guaranteeing meat and eating quality continues to be an ongoing challenge to red meat processors, as many measures of meat quality require resource intensive, destructive or subjective tests. Consequently, there is a need to develop rapid, non-invasive and non-destructive methods for meat quality assessment in commercial processing plants. Therefore, a preliminary investigation was conducted to determine the potential for a hand-held Raman spectroscopic device to predict meat quality and sensory traits measured by an untrained consumer panel. To this end, 45 beef loins (m. longissimus thoracis) were measured using a 671nm hand-held Raman spectroscopic device. Once spectra were collected, loins were frozen until sensory testing and shear force measurements. Further sub-samples were also collected to measure traits including sarcomere length, particle size, pH and colour. Derived models indicate that using Raman spectra it was possible to predict juiciness and tenderness, with cross validated correlations between the predicted and observed values (R2cv) of 0.42 (RMSEP = 11.29) and 0.47 (RMSEP = 10.52). A tentative band assignment suggests that these predictions may be based on changes to the biochemical characteristics of the muscle asso-ciated with hydrophobicity of proteins, fatty acid composition and the collagen matrix. However, further research is required to determine the repeatability and robustness of these models on a larger independent data set. }, issn = {1176-5283}, author = {Fowler SM and Schmidt H and Hopkins DL} } @conference {3672, title = {Changes in rumination behaviour after abrupt or diluted-milk weaning methods in goat kids}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {161-163}, address = {Rotorua}, abstract = {Rumination development is vital during weaning, when kids are transitioning from a reliance on milk to hard feeds. This study analysed rumination behaviour prior to, and following, two weaning methods: abrupt milk removal, and dilution of milk with water; both are common weaning practices on farm. We hypothesised that the dilution weaning method would better prepare kids to cope with the transition to full rumination. Thirty, 13-week-old Saanen cross goat kids were housed in pens of five. Two kids were nominated, for observation, from six pens (n=6/treatment). Kids had free choice access to hay, straw, water and a pelleted ration. Rumination behaviour was continuously recorded for two 24 h periods, before weaning and after weaning. Weaning treatment had no effect on rumination behaviour, though, both daily rumination time and number of boli regurgitated increased following weaning (3.6 vs. 5{\textpm}0.4 h/d, and 289 vs. 403{\textpm}29 boli/day). Rumination may be unaffected by using either weaning method, provided the kids have had access to forages and are not weaned too early. Early development of rumination allows kids to cope with milk removal and the switch to solid food, and quantifying its development is important to create best practice guidelines for the weaning period.}, issn = {1176-5283}, author = {Freeman HBR and Webster JR and Zobel G} } @conference {3672, title = {A comparison of faecal sample collection times for estimating faecal output and total tract digestibility using inert markers in sheep offered three ryegrass cultivars at two allowances}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {43-48}, address = {Rotorua}, abstract = {The objective of this study was to compare different faecal sampling regimes (collected in the morning (am) or the afternoon (pm), or the weighted mean of both times) for determining the concentrations of faecal markers (the natural odd-chain n-alkanes (C27 {\textendash} C35) contained in feed, the dosed (once daily in the morning) synthetic n-alkanes (C32 and C36) and titanium dioxide (TiO2)) and their accuracy for estimating dry matter digestibility (DMD) and faecal dry matter (DM) output from wethers (n = 30) fed cut ryegrasses. The concordance correlation coefficient (CCC) with measured faecal DM output was strong (CCC = 0.8) for faecal DM output predicted from the mean concentration of C32 in morning and afternoon faeces (am+pm), moderate (CCC = 0.6-0.7) when predicted from TiO2 am and am+pm, and weak when predicted from C36. The DMD predicted by C27 and C33 at either collection time, and by C29 and C31 for samples collected in the pm, were similar to measured DMD. The estimated DMD based on faecal C35 had a negligible CCC with measured DMD (CCC<0.1), while other natural n-alkanes had a low to moderate CCC (0.3-0.6) with measured DMD, especially for the samples collected pm and am+pm. For applications with grazing animals, where marker dosing and faecal sampling is often restricted to once daily in the morning for practical reasons, TiO2 was the most accurate marker to estimate faecal DM output and C31 or C33 were the most accurate and precise markers to estimate DMD.}, issn = {1176-5283}, author = {Jonker A and Cosgrove GP} } @conference {3672, title = {Comparison of health and reproductive treatments over three seasons for once-a-day and twice-a-day milking herds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {211-215}, address = {Rotorua}, abstract = {Once-a-day (OAD) milking has been increasing in popularity in New Zealand, while housing cows is being advocated as one means of minimising environmental impacts of dairying. The present study aimed to investigate health treatments under four different farming systems: OAD, and three twice-a-day (TAD) systems (housed, standard and commercial). There were health records from 377 cows milked OAD and 878 cows milked TAD, over the dairy seasons 2013-14, 2014-15 and 2015-16. Data were analysed assuming binomial distributions for the dependent variables with a generalised linear model that included the effects of season, system (OAD, TAD systems), breed and lactation number. In 2014-15, cows milked OAD were treated less often for mas-titis than cows milked TAD (12\% and 25\% respectively; P<0.05). Cows milked OAD had fewer reproductive treatments compared to cows milked TAD (standard) in 2014-15 and 2015-16 (1\% vs 39\% and 2\% vs 40\% respectively; P<0.01). These results support the advice to farmers that milking OAD does not have a major impact on the risk of mastitis but may provide benefits in terms of reproductive performance. In addition, cows milked TAD (housed) had 13\% of the cows treated for lameness compared to 7\% of cows milked TAD (standard) (P<0.01). }, issn = {1176-5283}, author = {Van Der Spek P and Sneddon NW and Lopez-Villalobos N and Donaghy DJ and Laven RA and Mueller KR and Amoore J and Doohan H} } @conference {3672, title = {Contract session: An overview of postpartum hyperketonaemia and its association with cow health and performance in pasture-based dairy systems}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {104-106}, address = {Rotorua}, abstract = {Following calving, dairy cows undergo a period of negative energy balance during which they mobilise body tissue (such as fat) to support the demands of lactation. When the negative energy balance is severe, the inability of the liver to process all the mobilised fatty acids can lead to hepatic lipidosis (i.e., fatty liver disease) and incomplete fatty acid oxidation. The latter results in the hepatic production of ketone bodies, predominantly β-hydroxybutyrate (BHB), which are released into the circulation as the product of ketogenesis. The increased concentration of ketones in blood is known as hyperketonaemia...}, issn = {1176-5283}, author = {Phyn CVC and Kuhn-Sherlock B and Turner S-A and Grala TM and Burke CR and Roche JR} } @conference {3672, title = {Contract session: BVD bulk milk testing}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {93-94}, address = {Rotorua}, abstract = {

Bovine Viral Diarrhoea (BVD) is a highly prevalent and infectious viral disease found in cattle in New Zealand, and in many other countries around the world. It is a widespread disease and it is estimated that up to 60\% of NZ dairy and beef cows have been exposed to BVD (BVD Steering Committee 2017, http://www.controlbvd.org.nz).

The BVD virus (pestivirus) has damaging effects on the health, reproductive performance, growth, and productivity of a dairy herd and sometimes causes death. The production losses are significant; estimated annual losses for NZ dairy farmers are around $127 million. The cost for our beef farmers is around $3000-$9000 per 100 cows in infected herds (BVD Steering Committee 2017, http://www.controlbvd.org.nz). BVD is a serious threat to our farmers, but also to New Zealand{\textquoteright}s economy...

}, issn = {1176-5283}, author = {Lowe AD} } @conference {3672, title = {Contract session: Caprine arthritis encephalitis in New Zealand dairy goat farms}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {97-99}, address = {Rotorua}, abstract = {

Caprine arthritis-encephalitis (CAE) is a widespread disease in goats that was first reported in New Zealand in 1981 (Oliver 1982; Oliver et al. 1983). The disease is caused by a lentivirus (CAEV) which, like all retroviruses, inserts its genome into the DNA of the cell it infects. CAEV infects and replicates within monocytes and macrophages and these immune cells then carry the virus throughout the body. Seroconversion typically occurs slowly (months rather than weeks) and there is no simple relationship between the initial infection and moment of conversion.

All breeds and ages of goats are susceptible to infection and, once established, it persists throughout the animal{\textquoteright}s life. Progression of the disease can take months to years and it is unusual to observe gross clinical signs prior to two years of age. Not all goats that are infected with CAEV will develop the disease and these asymptomatic carriers may spread the disease within the herd. The most common symptom of CAE is chronic arthritis in adult animals. Bilateral or unilateral swelling of the carpal region is common, hence the lay term {\textquoteleft}big knees{\textquoteright}. Infection can also lead to weight loss and/or impaired milk production (Greenwood 1995).

The major transmission route of CAEV is through the ingestion of virus-infected colostrum by kids, although lateral transmission through prolonged close contact with infected animals is also thought to occur (Adams et al. 1983) and, more recently, evidence suggests that vertical transmission from the reproductive tract of infected females to their offspring is possible (Hasegawa et al. 2017). CAEV has been found in semen, so it is also possible that a doe may get the disease from an infected buck (Souza et al. 2013).

}, issn = {1176-5283}, author = {Pryor SM} } @conference {3672, title = {Contract session: Evaluation of the performance of real time PCR for detection of Staphylococcus aureus in dairy cows, using herd test milk samples}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {95-96}, address = {Rotorua}, abstract = {

Mastitis in dairy cattle is of considerable consequence in NZ, with estimates of over $200 million per annum loss of potential earnings caused by reduction in milk quality and decreased production (Blackwell \& Lacy-Hulbert 2012).

Somatic cell count (SCC) is used by farmers for udder health monitoring{\textendash}with an increase in cell count being an indicator of infection. On-farm, monitoring the bulk milk (BM) SCC is used to gauge sub-clinical mastitis infection in the herd. An increase in or a consistently high BM SCC can indicate infection. Herd Testing (HT) provides the individual animal SCC. The Smart SAMM guidelines Seasonal Approach to Managing Mastitis 2011 plan suggests a target for national average bulk-milk somatic cell count of less than 150,000 cells/ml (Woolford et al. 1995), BMSCC exceeding 400,000 cells/ml are subject to dairy company penalties. Individual animal SCCs of over 150,000 cells/ml, or 120,000 cells/ml for heifers, are indicative of an infection...

}, issn = {1176-5283}, author = {Thresher RA} } @conference {3672, title = {Contract session: Facial eczema prevention}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {100-103}, address = {Rotorua}, abstract = {

Facial eczema (FE) significantly impacts on the health and productivity of cattle (Towers \& Smith 1978) and presents significant welfare concerns. The clinical manifestations of FE arise from damage to the liver. When spore count challenges are low to moderate and sustained, low-grade, chronic liver damage can then result in sub-clinical FE, a condition characterised by suboptimal productivity with little or no clinical signs. It is likely that sub-clinical FE goes un-noticed by many herd managers.

Whenever there is a significant FE challenge, farmers tend to recognise the presence of disease by identifying photosensitization in individual cows. It is possible for images of affected animals to be made public via animal welfare groups. This presents a risk to New Zealand{\textquoteright}s {\textquoteleft}clean green image{\textquoteright} and reputation for sustaining a high level of animal welfare in farmed livestock. However, photosensitisation represents only the tip of the iceberg of a herd-level FE problem. Research has shown that only a small proportion of cows within a herd affected by FE have photosensitisation, with a much greater proportion having significant liver damage without any obvious clinical signs (Di Menna et al. 2009). The causative agent of FE (a fungus, Pithomyces chartarum) was first identified in New Zealand in 1958. Since then protocols for management of the problem have been developed, mostly involving regular administration of zinc (Zn) salts to cattle by mouth. However, over the years a number of alternative management ideas for controlling facial eczema have also been tried and farmers have been discussing these methods with some conviction for years.

}, issn = {1176-5283}, author = {Cuttance W and Cuttance E} } @conference {3672, title = {Culling reasons in once-a-day milking cows and differences in production and type traits between retained and culled cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {200-204}, address = {Rotorua}, abstract = {The aim of this study was to investigate the culling reasons in cows milked once-a-day (OAD), evaluating the differences of production, fertility and traits other than production (TOP) between retained and culled cows. Cows in different lactations from Massey University Dairy 1 were scored for 18 TOP for three consecutive seasons from 2013 to 2015. Herd-test records were used to estimate milk yield (MY), fat yield (FY), protein yield (PY) and somatic cell score (SCS). Low fertility, poor udder conforma-tion and low production were the main reasons for culling in all seasons. Overall, culled cows had a lower MY (3534{\textpm}56 kg), FY (173.5{\textpm}2.8 kg), PY (138.5{\textpm}2.1 kg) and higher SCS (6.41{\textpm}0.09) than retained cows (MY = 4006{\textpm}41 kg; FY = 204.7{\textpm}1.9 kg; PY = 160.6{\textpm}1.5; SCS = 6.19{\textpm}0.06). Culled cows had a poorer adaptability to milking (7.02 {\textpm} 0.04) and poorer farmer{\textquoteright}s overall opin-ion (7.62{\textpm}0.06) than retained cows (7.23{\textpm}0.03 and 7.89{\textpm}0.04, respectively). Moreover, culled cows had a weaker udder support (5.56), weaker front udder (5.48) and lower rear udder (6.01) than retained cows (6.19, 5.85 and 6.25, respectively). These traits might have a higher influence on the culling decisions of OAD dairy farms than the age and production worth of cows.}, issn = {1176-5283}, author = {Rocha JF and Lopez-Villalobos N and Burke JL} } @conference {3672, title = {Development of value-added lamb cuts for the modern consumer}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {185-188}, address = {Rotorua}, abstract = {As genetics and management practices have improved within the Australian lamb industry, the weight of lamb carcases has in-creased. Yet, the demographics of lamb consumers and their consumption patterns have changed, as household size has become smaller. Consequently, the traditional lamb cuts have less appeal to consumers from smaller households when taken from heavy carcases (>25kg). Therefore, research has been conducted to determine the potential for fabricating new cuts from heavier lamb carcases, determine the nutritional composition of new cuts and examine the impact of increasing carcase weight and fat depths on the time and labour required to process larger carcases into smaller cuts. Development of an information matrix of available lamb data on the eating and nutritional qualities and contribution to total carcase yield highlighted the potential to create further val-ue-added cuts from the forequarter and leg. However, the time taken to fabricate these increasingly value-added cuts from heavier carcases increased with carcase weight (0.44 minutes/kg (s.e. = 0.065) and changes to the saleable meat yield resulted in increased average product prices. Based on the program, a new cut called the Compact Shoulder Roast was developed to provide an option for retailers when processing heavy carcases. This paper outlines some of the outcomes of this program. }, issn = {1176-5283}, author = {Fowler SM and Pethick DW and Hopkins DL} } @conference {3672, title = {Effect of cow body condition score on inter-calving interval, pregnancy diagnosis, weaning rate and calf weaning weight in beef cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {23-28}, address = {Rotorua}, abstract = {The aim of this study was to describe the effect of cow body condition score (BCS) on pregnancy rate, inter-calving interval, wean-ing rate and birth and weaning weights of calves. Measurements of BCS in a herd of mixed age (2-10 years), predominantly Angus, beef cows were recorded annually four times between November 2012 and March 2015, at joining/rebreeding (November), wean-ing/pregnancy diagnosis (PD, March), winter (June) and calving (August). Year influenced BCS (P<0.05) and BCS was greatest at weaning 2014. Two-year-old cows had greater BCS (P<0.05) than three-year-old and the mixed age cows. Pregnancy rate was no different (P>0.05) between BCS at calving, joining and PD. Cows that increased BCS from joining to PD had lower pregnancy rate than cows that maintained or decreased BCS during this period, although it is unclear whether this association reflects an influence of BCS on pregnancy rate, or whether the BCS change was a result of differing pregnancy status. Greater BCS at joining was associated with lower calf birth weights. Body condition score at each event was not associated with inter-calving interval or calf weaning weight. Further research is still required to determine the optimum BCS at each stage of the production cycle.}, issn = {1176-5283}, author = {Tait IM and Morris ST and Kenyon PR and Garrick DJ and Pleasants AB and Hickson RE} } @conference {3672, title = {The effect of grazing ewe lambs on lucerne (Medicago sativa) prior to breeding on aspects of reproductive performance}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {55-60}, address = {Rotorua}, abstract = {Ewe lamb breeding can result in low and variable reproductive performance which is one of the reasons given by farmers for not breeding their ewe lambs. Ewe lamb twinning rates are known to be increased with greater ewe liveweight gain in the weeks leading up to the introduction of the ram. The hypothesis was that offering lucerne for a one-month period that ended 14 days prior to breeding would alter the pattern of breeding (i.e. cycle of conception) and pregnancy and reproductive rates of ewe lambs. Of-fering lucerne had no effect (P>0.05) on the pattern of breeding in both years of the study, respectively. Offering lucerne, however, resulted in a greater percentage of ewe lambs diagnosed with twin-fetuses compared to those offered unimproved ryegrass pastures in 2015 (35\% vs. 18\%, respectively). In 2016, however, there was no effect of grazing lucerne on reproductive rate. The difference between years was likely the result of lower lucerne masses offered in 2015 than in 2016. }, issn = {1176-5283}, author = {Corner-Thomas RA and Panns JM and Kemp PD and Morris ST and Kenyon PR} } @conference {3672, title = {The effect of live weight at weaning on liveweight gain of early weaned lambs onto a herb-clover mixed sward}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {37-42}, address = {Rotorua}, abstract = {Twin lambs that weighed a minimum of 16 kg (n=134 in 2014 and n=124 in 2015) were randomly allocated to one of three treat-ments: (i) Early weaning (54 and 46 days after the midpoint of lambing in 2014 and 2015, respectively) onto a herb-clover mixed sward (plantain, chicory, red clover and white clover) (HerbEW); (ii) Lambs + dams unweaned on a herb-clover mixed sward until conventional weaning at approximately 13 weeks of age (HerbCW); and (iii) Lambs + dams unweaned on a grass-clover mixed sward until conventional weaning (GrassCW). In 2014, overall greater (P<0.05) liveweight gains were found in HerbCW lambs followed by HerbEW and GrassCW lambs. In 2015, liveweight gains of HerbCW and GrassCW lambs did not differ (P>0.05), but were greater than gains of HerbEW lambs (P<0.05). In 2014, HerbEW lambs that were > 20 kg grew more quickly than HerbEW lambs that were <18 kg (P<0.05). In 2015, HerbEW lambs had similar rate of liveweight gain irrespective of their live weight at treatment allocation (P>0.05). Lambs can be weaned early onto herb-clover mixed swards and achieve greater liveweight gains after wean-ing compared to lambs unweaned on grass-clover mixed sward. Weaning lambs less than 20 kg onto herb-clover mixed sward, however, can result in lower lamb liveweight gain compared to heavier lambs.}, issn = {1176-5283}, author = {Ekanayake WEMLJ and Corner-Thomas RA and Cranston LM and Kenyon PR and Morris ST} } @conference {3672, title = {The effect of mid-pregnancy nutrition and body condition score on the behaviour of triplet-bearing ewes and their lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {143-148}, address = {Rotorua}, abstract = {Nutrition of ewes during pregnancy may affect the behaviour of ewes and their lambs in the first few days of life. In this experiment, triplet-bearing ewes were allocated {\textquoteleft}medium{\textquoteright} (pasture mass 800-1200 kg DM/ha) or ad-libitum nutrition (pasture mass 1500-2000 kg DM/ha) from day 93 until 114 of pregnancy. Both treatments included ewes of body condition score (BCS) <=2.0, 2.5 or >=3.0 as measured on day 92 of pregnancy. Behaviours of ewes and lambs were recorded in the paddock at tagging and a subset of lambs was subjected to a maternal-recognition test. Within the BCS<=2.0 ewe group, lambs born to ewes on the medium treatment emitted more high-pitched bleats and lower low-pitched bleats than lambs born to ewes on the ad-libitum treatment. In the paddock, there was no effect of ewe feeding treatment or BCS group on the median time taken for the lambs to stand, make contact with, suck from or follow their dam. In the maternal-recognition test, the median time taken for the lambs to reach the dam and the time the lambs spent with her was not affected by ewe BCS or feeding treatment. Overall the results indicate that feeding triplet-bearing ewes above pregnancy requirements has minimal effect on lamb behaviours. There is, however, some evidence to suggest that lambs born to ewes in the BCS<=2.0 group offered the medium treatments may have experienced a weaker ewe-lamb bond. }, issn = {1176-5283}, author = {Gronqvist GV and Hickson RE and Corner-Thomas RA and Stafford KJ and Morris ST and Kenyon PR} } @conference {3672, title = {Effect of slaughter age between 5 to 14 months of age on the quality of sheep meat}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {177-180}, address = {Rotorua}, abstract = {Pasture-raised lamb is considered the highest-quality sheep meat product while hogget is a downgraded product considered to be of poorer quality. This experiment aimed to investigate the difference in meat quality between sheep slaughtered at 5, 8 and 14 months of age. Objective meat quality was measured on the loin of young Romney rams slaughtered at 5 (n=20), 8 (n=20) and 14 (n=20) months old. The loin meat from 14-month-old sheep was redder (P<0.001), yellower (P<0.001) with higher intramuscular fat (P=0.003) and had a shorter sarcomere length (P<0.001) compared to the meat from lambs slaughtered at 5 and 8 months of age. The peak shear force was highest at 8 months (P<0.001). Meat from sheep slaughtered at 8 months had greater drip loss than those at 5 and 14 months (P<0.01). The results suggest that slaughtering sheep at 14 months could have benefits on eating quality due to an increase in intramuscular fat. }, issn = {1176-5283}, author = {Mashelea GA and Parker ME and Schreurs NM} } @conference {3672, title = {The effect of yard weaning and contact with humans on behavioural reactivity and liveweight gain of beef breed calves}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {8-12}, address = {Rotorua}, abstract = {Yard weaning of beef-breed calves is growing in popularity in New Zealand as a way of improving ease of handling, but there is little scientific literature regarding the practice. This experiment examined the effects of yard weaning versus paddock weaning with and without human contact on liveweight gain and behaviour. Paddock-weaned calves lost more live weight in the first sev-en days after weaning (-1.19 {\textpm} 0.17 kg/d versus -0.60 {\textpm} 0.16 kg/d; P=0.01) than yard-weaned calves but live weight was similar between treatments 42 days after weaning (D42). Yard-weaned calves tended to be less reactive than paddock-weaned calves on D7 (2.16 {\textpm} 0.28 versus 2.92 {\textpm} 0.33; P= 0.07, where one is least reactive and five is most reactive), but there were no differences in reactivity on D42. Faecal corticosterone concentrations were similar between weaning location, however, calves with minimal human contact had higher faecal corticosterone concentrations 48 hours after weaning than did calves with daily human contact (27.6 {\textpm} 2.11 ng/ml versus 18.6 {\textpm} 2.11 ng/ml; P<0.01), regardless of location. There were short-term advantages in live weight and heart rate associated with yard weaning of beef-breed calves, but these did not persist to D42. }, issn = {1176-5283}, author = {Ramsay BA and Schoorl JAJ and Stayton KM and Cranston LM and Morris ST and Burnham DL and Cockrem JF and Beausoleil NJ and Hickson RE} } @conference {3672, title = {The effects of early access to meal on the behaviour of artificially reared dairy lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {18-22}, address = {Rotorua}, abstract = {he New Zealand sheep dairy industry is growing (Peterson \& Prichard 2015). Several large commercial sheep dairy farms remove lambs from their dams within the first four days of life. In some systems, lambs have access to milk replacer (MR) ad libitum and a grain-based solid feed (Bimczok et al. 2005). Compared to young ruminants fed a milk-only diet, early access to solid feed stimulates rumen development (Baldwin et al. 2004) and earlier onset of rumination (Khan et al. 2016) to allow early weaning off MR (Bimczok et al. 2005). Earlier rumen development through access to meal may also encourage earlier grazing of pasture and greater rumination, thereby supporting early weaning. The potential to replace meal with early pasture access as the sole solid feed source to support early weaning has not been evaluated...}, issn = {1176-5283}, author = {Nieper BA and Khan MA and Ganesh S and Knol FW and Peterson SW and Stafford KJ and Stevens DR and McCoard SA} } @conference {3672, title = {Estimates of genetic parameters for direct and maternal genetic effects on weaning weights in Dairymeade sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {129-132}, address = {Rotorua}, abstract = {Dairymeade is a newly registered breed of dairy sheep in the emerging New Zealand dairy sheep industry. The objective of this study was to estimate heritabilities and genetic correlations for direct and maternal genetic effects on weaning weight, as this trait reflects the genetic ability of the lamb to grow (direct genetic effect), and the genetic ability of the ewe to feed her lambs (maternal genetic effect) and protect them (maternal permanent environment). Records of weaning weight were used from 717 lambs born between 2013 and 2016, with a pedigree of 5091 animals over 11 generations. Average and standard deviation of weaning weight, age at weaning and litter size were 18.1{\textpm}4.0 kg, 51.5{\textpm}13.0 days and 2.16{\textpm}0.7 lambs, respectively. At weaning, ewe lambs were 1.1 kg (SE=0.2 kg, P<0.05) lighter than ram lambs and singleton lambs were 4.1 kg (SE=2.9 kg, P<0.05) heavier than triplet lambs. Estimates of heritability ({\textpm}SE) were 0.55 ({\textpm}0.24), 0.24 ({\textpm}0.17) and 0.28 ({\textpm}0.13) for direct, maternal and total genetic effects, respectively. The proportion of total variance explained by maternal permanent environmental influences was 0.14 ({\textpm}0.07). The estimated genetic correlation between direct and maternal genetic effects was -0.72 ({\textpm}0.20). Maternal breeding values can be used to select ewe lambs specifically for milk production.}, issn = {1176-5283}, author = {Lopez-Villalobos N and King M and King J and Morris RS} } @conference {3672, title = {Field investigation of the iodine status of farms in the North Island of New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {77-81}, address = {Rotorua}, abstract = {Over a 10-year period 104 farms in the North Island were attended on a consultancy basis, and of these, 29 farms were identified as having clinical signs associated with iodine deficiency (high peri-natal calf mortality, poor conception rate and/or low pregnancy rate). Mean pasture iodine concentrations (n=24) were 0.28 mg/kg (SD=0.16) ({\textquoteleft}adequate{\textquoteright} range: 0.40-0.80 mg/kg). Mean animal plasma inorganic iodine (PII) concentrations (n=17) were 40.6 μg/L (SD=16.28) ({\textquoteleft}inadequate{\textquoteright} range <45 μg/L). Marginally low iodine status (20-45 μg/L) was present in 13.5\% of farms (14 of 104). The overall average deficit for the farms with low pasture iodine (n=19) was calculated to be 3.0 mg iodine per cow per day. Corrective treatment was computed for each farm and made pri-marily through weekly addition of iodine to the drinking water. Following iodine supplementation, mean animal PII was 60.8 μg/L (SD=19.50), a 50\% increase over initial values. For individual cattle, there was a significant reduction in the proportion (73.5\% to 23.5\%) whose PII was marginally low (P=0.001). Clinical responses in livestock were monitored, and on the iodine supplemented farms there was some evidence for a reduction in peri-natal calf mortality and an increase in conception rates, but the amount of data was limited. Iodine supplementation was seen to contribute to an overall increase in pregnancy rates on ten farms (from 79.4\% to 91.1\%). It is concluded that iodine deficiency is common in North Island pasture-based livestock farms, that it is responsive to dietary supplementation, and that supplementation may be associated with improved reproductive performance.}, issn = {1176-5283}, author = {Anderson PD and McGhie DON and Parkinson TJ} } @conference {3672, title = {Growth curves of New Zealand Holstein-Friesian, Jersey and Holstein-Friesian-Jersey crossbred heifers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {64-68}, address = {Rotorua}, abstract = {There are differences in the proportion of target live weight (LWT) achieved between the main breeds of dairy heifers in New Zealand, suggesting a potential difference in growth pattern. The objectives of this study were to model growth curves of dairy heifers through random regression of Legendre polynomials, and to compare growth curves of the main breeds. Data comprised of 1,653,214 LWT records obtained from 189,936 dairy heifers in 1,547 herds. The fourth-order Legendre polynomial was the best at predicting LWT, with a relative prediction error (RPE) of less than 4\% for the whole dataset and for Holstein-Friesian, Jersey and Holstein-Friesian-Jersey crossbred (F{\texttimes}J) heifers. The regression coefficients of the growth curve differed among breeds for the intercept (α0; P<0.001), linear effect (α1; P<0.001), quadratic effect (α2; P<0.001), cubic effect (α3; P<0.001) and quartic effect (α4; P<0.001). At all ages Holstein-Friesian heifers were heavier than F{\texttimes}J which were heavier than Jersey heifers (P<0.001). The percentage difference among the breeds varied throughout the growth curve, indicating that the main breeds of dairy heifers in New Zealand exhibited different growth patterns that were non-linear. The different growth patterns for each breed should be considered when formulating target LWTs and growth rates.}, issn = {1176-5283}, author = {Handcock RC and Lopez-Villalobos N and McNaughton LR and Edwards GR and Hickson RE} } @conference {3672, title = {How does feeding meal affect growth of artificially reared East Friesian-cross dairy lambs?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {13-17}, address = {Rotorua}, abstract = {Artificial rearing is routinely used in large-scale dairy sheep farms. One approach is to offer milk replacer (MR) and meal ad libi-tum to lambs. Our aim was to evaluate growth performance of female lambs in the first 12 weeks of rearing with (M) and without (NM) grain-based meal access (n=30/group) during four feeding periods. In period 1 (wk 0-3) lambs were offered MR and meal ad libitum, and in period 2 (wk 4-5) were transitioned outdoors onto pasture with continued access to MR and meal. Lambs were weaned off MR in period 3 (wk 6-10), and meal in period 4 (wk 10-12). The NM lambs received identical management but meal was excluded. A treatment-by-time interaction was found whereby NM lambs had lower average daily gain (ADG) (P<0.05) in periods 1 (376{\textpm}6 vs. 414{\textpm}8 g/day) and 3 (146{\textpm}7 vs. 241{\textpm}7 g/day), no difference in period 2 (P>0.05), and higher ADG in period 4 (157{\textpm}18 vs. -55{\textpm}18 g/day, P<0.05) than M lambs. There was no difference (P>0.05) in live weight by week 12, and all lambs survived. These results indicate when lambs fed MR ad libitum are offered unrestricted access to good-quality pasture before weaning, meal may not be required to achieve a similar live weight at 12 weeks.}, issn = {1176-5283}, author = {Jensen AC and Khan MA and Knol FW and Peterson SW and Morel PCH and McKenzie C and Stevens DR and McCoard SA} } @conference {3672, title = {Impact of early weaning on rumen fermentation profiles of artificially reared lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {49-54}, address = {Rotorua}, abstract = {This study investigated the impact of weaning age on rumen fermentation profiles in lambs. Mixed-sex lambs (n=32) were ran-domly allocated to one of two weaning groups: early-weaning (4wk) and control (6wk). Milk replacer (24\% CP and 25\% fat, DM basis) was offered at 20\% of initial body weight. Lambs were weaned at either four or six weeks after commencement of the trial using a three-week step-down procedure, initiated at the start of week 2 (early weaned group) or week 4 (control group). Lambs were individually penned indoors and concentrate and chopped meadow hay were offered ad libitum and individual feed intakes recorded until week six. At the end of week six, lambs were moved onto a ryegrass-based pasture and transitioned to an all pasture diet by week ten. Rumen contents were collected at slaughter, half of the lambs from each group at week four and sixteen, to de-termine rumen pH, and short chain fatty acid (SCFA) and ammonia concentrations. Ammonia concentrations were 132\% greater (P<0.05) in early weaned than control lambs at week four, but did not differ at week sixteen. Weaning age did not affect ruminal pH and SCFA total concentrations and proportions at week four or sixteen. The results suggest that ruminal fermentation can be established in lambs weaned off milk by four weeks using a step-down weaning method.}, issn = {1176-5283}, author = {Cristobal-Carballo O and Khan MA and Knol FW and Lewis SJ and Stevens D and McCoard SA} } @conference {3672, title = {Intramuscular fat content of New Zealand lamb M. longissimus lumborum}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {189-193}, address = {Rotorua}, abstract = {

The content of intramuscular fat (IMF\%) in lamb is an important trait for the lamb-meat value chain. Not only is IMF\% an import-ant energy reserve for replacement stock, IMF\% is an important driver of lamb-meat eating quality. A growing body of research shows an antagonistic relationship between muscle growth traits and fat content across the lamb carcass (including IMF\%). The New Zealand sheep industry has selected for muscle growth traits for decades to improve production efficiency and reduce extremes of carcass fatness historically observed, but the impacts on IMF\% levels in New Zealand lamb have not been widely investigated.

This paper aims to stimulate discussion on lamb IMF\% by reporting on levels of IMF\% observed in the M. longissimus lumborum (LL) of 1,705 progeny test lambs raised under extensive, pasture-based production systems across New Zealand, and investigates the relationship between IMF\% and carcass weight, VIAscan{\textregistered}-predicted GR (VSGR) and lean-meat-yield percentage (VSYLD).

The average IMF\% was 2.69\%, (SD = 0.83\%, and ranged between 0.91-6.42\%). IMF\% is positively correlated with carcass weight and VSGR and negatively correlated with VSYLD. Considerable variation exists in lamb IMF\%, highlighting the opportunity to manage IMF\% through genetic improvement and optimised on-farm management.

}, issn = {1176-5283}, author = {Craigie CR and Agnew MP and Stuart AD and Shorten PR and Reis MM and Taukiri KR and PL Johnson} } @conference {3672, title = {Mechanical properties of black, grey, and white hoof material of sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {154-158}, address = {Rotorua}, abstract = {A study was undertaken to better understand the care and attitudes towards rams on NZ commercial farms. Farms (n=22) were surveyed in Otago and South Canterbury giving indicative data on the treatment and attitudes that commercial farmers have towards rams. On average (SD; Range) the number of ewes put to each ram was, for maternal and terminal sires respectively, 92 (21; 56-143) and 84 (20; 50-100). The reported difference between when rams were put to ewes and when lambs were weaned was 319 days (51; 199-359). Rams were typically put to ewes in April and early May, and weaned as early as November. Visual assessment was most commonly used to assess rams for purchase, with most farmers considering visual attributes and then figures, such as breeding values, to choose rams. The average mortality of rams was reported as 5\% (7\%; 0-28\%). The average culling of maternal and terminal sires over the year was respectively 26 and 29\%. Annual health checks by a vet were reported for 45\% of the farms. A most common reason for checking was for Brucella ovis testing. This research will provide information to guide further studies on commercial sheep farms.}, issn = {1176-5283}, author = {Scobie DR and Makela AG and van Koten C and O{\textquoteright}Connell D} } @conference {3672, title = {Oocyte maturation and quality in dairy heifers with diverse genetic merit for fertility}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {29-33}, address = {Rotorua}, abstract = {Oestrous behaviour, cumulus cell-oocyte complex (COC) quality, and steroid concentrations were characterised in dairy heifers of high and low values for fertility breeding value (FBV). The hypothesis was that the greater FBV is partly mediated through improved oocyte quality. Ovum pick-up (OPU) was used to collect COCs from the preovulatory follicle of 40 heifers observed in oestrus. Multiplex Taqman qPCR was used to investigate gene expression in cumulus cells (eight genes) and oocytes (three genes) of the recovered healthy COCs (n=9 per group). Plasma and follicular fluid steroid concentrations were measured using high-performance liquid chromatography. Low-FBV heifers were more active in the first eight hours of oestrus (P<0.05), leading to earlier detection and OPU (P<0.05). Consequently, COCs recovered from low-FBV heifers were morphologically less mature (P<0.05) and tended to have lower expression of genes regulating maturation compared with high-FBV heifers. Our findings suggest COC development is retarded in low-FBV heifers relative to the timing of visually observed oestrus, which may result in a poorly developed oocyte at ovulation. }, issn = {1176-5283}, author = {Reed CB and Meier S and Pitman JL and Burke CR} } @conference {3672, title = {The percentage of spring-calving carryover cows in New Zealand dairy herds and their milk production, compared to heifers, age-matched and lactation-matched non-carryover cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {3-7}, address = {Rotorua}, abstract = {Non-pregnant cows are generally culled from dairy herds and replaced with heifers. Alternatively, non-pregnant cows can be dried-off at the end of lactation, retained for one year (carried over), before being mated and returned to a milking herd in the following year. The aim of this study was to estimate the percentage of spring-calving carryover cows in New Zealand dairy herds and to compare their milk production with that of heifers, lactation-matched and age-matched non-carryover cows. Results showed that 2.5\% of spring-calving cows had experienced a previous carryover period. The majority (43\%) of carryover cows had failed to conceive during their first lactation. Most (69\%) dairy herds contained less than 5\% carryover cows and 17\% had zero carryover cows. Second-lactation carryover cows produced 4778.1{\textpm}6.3 L milk, 228.7{\textpm}0.3 kg fat, 182.0{\textpm}0.2 kg protein, and had a somatic cell score (SCS) of 6.31{\textpm}0.01, which was greater (P<0.001) than the milk production of heifers that produced 3514.5{\textpm}5.9 L milk, 168.3{\textpm}0.3 kg fat, 134.0{\textpm}0.2 kg protein, and had a SCS of 5.89{\textpm}0.01. Carryover cow milk production was also greater (P<0.001) than that of lactation-matched and age-matched non-carryover groups. The results of this study will aid on-farm culling decisions.}, issn = {1176-5283}, author = {Gardner RR and Back PJ and Lopez-Villalobos N and McNaughton LR} } @conference {3672, title = {Potential anthelmintic properties of urea}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {110-113}, address = {Rotorua}, abstract = {Current gastrointestinal parasite treatment options rely heavily on chemical anthelmintic intervention which targets the nematode residing in the host. However, targeting these organisms during parts of their lifecycle outside the host may also provide a tool for aiding control. In particular, nitrogenous fertilisers produce several potentially toxic compounds, the strategic use of which may affect nematode development. This series of experiments investigated the potential of liquid urea to affect gastrointestinal nematode development. Hatching of Trichostrongylus colubriformis eggs when immersed in liquid urea reduced with increasing urea concentration from 90\% at 0\% urea to less than 6\% in 20\% urea solution. This effect was independent of pH and appeared to be nematocidal rather than nematostatic as unhatched eggs failed to hatch following washing and immersion in water. Further, topical application of liquid urea to faeces at a rate equivalent to 200 litres per ha (40 units N) on fresh faeces resulted in a 97\% reduction in the number of larvae recovered following culturing compared with equivalent rates of water (P<0.01). Although further studies and refinement are required, these studies indicated targeted application of liquid urea may be a useful tool to assist with parasite control.}, issn = {1176-5283}, author = {Cairns J and McAnulty RW and Greer AW} } @conference {3672, title = {Prototype genetic evaluation in a New Zealand dairy sheep flock}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {121-124}, address = {Rotorua}, abstract = {Dairy sheep milking is an emerging industry in New Zealand, but at present there is no national breeding scheme. A prototype model for the genetic evaluation of dairy sheep was developed. Data were obtained from a flock of 123 crossbred ewes, over 479 monthly flock tests during the season 2015/16. Breeding values were estimated for lactation yields of milk, fat, protein and lac-tose, and for live weight, somatic cell score, first let-down time and yield, and number of lambs born, from a multiple-trait animal model. Heritabilities and phenotypic and genetic correlations required for the model were obtained from the literature, and pheno-typic standard deviations were obtained from the data set. This prototype model to obtain estimated breeding values of animals in this flock can be extended to other dairy sheep farmers, to create selection schemes at industry level and start a systematic breeding program for the emerging New Zealand dairy sheep industry.}, issn = {1176-5283}, author = {Scholtens MR and Peterson SW and Gunson K and Gunson A and Lopez-Villalobos N} } @conference {3672, title = {Random regression curves for body condition score and live weight from cows in two different dairy systems over three seasons}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {72-76}, address = {Rotorua}, abstract = {As housing is adopted to minimise the environmental impacts of farming activities in New Zealand, it becomes important to investigate the impact of this on the body condition of cows as a predictor of animal welfare. The P21 project undertaken at Massey University{\textquoteright}s Dairy 4 recorded the body condition score (BCS) and live weight (LW) of cows either under duration-controlled grazing during sensitive periods ({\textquoteleft}housed{\textquoteright}) or standard feed-pad ({\textquoteleft}standard{\textquoteright}) system. A total of 10,350 BCS records and 10,950 LW records were available from 978 cows over three dairy seasons (2013-14 to 2015-16). Random regression curves for daily BCS and LW were modelled using a 5th order Legendre polynomial. Data were analysed with a linear model, which included the effects of system, season, the system by season interaction and proportion of breeds (Jersey and Friesian), and cow age fitted as co-variants. The BCS was greater in 2014-15 than in either 2013-14 or 2015-16, (4.48 vs 4.33 and 4.28, respectively). The BCS of the housed and standard cows were significantly different (P <0.01) in 2013-14 and 2015-16. Housed cows were heavier than standard cows in both 2013-14 and 2014-15. These results indicate that housing of cows could improve on their BCS and LW. }, issn = {1176-5283}, author = {Sneddon NW and Lopez-Villalobos N and Donaghy DJ} } @conference {3672, title = {Stand-off pad wintering system: effect of surface types on cow comfort and urination behaviour}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {137-142}, address = {Rotorua}, abstract = {Two consecutive experiments were conducted over four weeks during winter to investigate the effect of different stand-off pad surface types on dairy cow lying behaviour, cleanness and lameness scores, and urination frequency. In experiment one, 350 Frie-sian {\texttimes} Jersey, pregnant non-lactating dairy cows were blocked and assigned to five treatments for two weeks: fodder beet grazed in situ with no stand-off (control); fodder beet grazed in situ and cows spent 17 hours on a woodchip stand-off (WCG); harvested fodder beet bulb fed in paddock and cows spent 17 hours on a woodchip stand-off (WCH); fodder beet grazed in situ and cows spent 17 hours on a 70 mm round-stone stand-off (S70); fodder beet grazed in situ and cows spent 17 hours on a 50 mm round-stone stand-off (S50). In experiment two, 156 Friesian {\texttimes} Jersey, pregnant non-lactating dairy cows were blocked and assigned to three treatments for two weeks: control and WCG as described in experiment one, and a third geotextile {\textquoteleft}carpet{\textquoteright} stand-off for 17 hours (GC). In experiment one, surface type had no effect on lying time (average 10.1 hours), cleanness and lameness score, or urination behaviour. In experiment two, lying hours were greater (P=0.01) for cows on carpet (11.6) than for cows on woodchip (10.8). While current results showed a negligible effect of surface type on cow comfort and urination behaviour during winter, a longer study, covering the whole winter season, is required to confirm these results. }, issn = {1176-5283}, author = {Al-marashdeh O and Cameron KC and Bryant RH and Box L and Arends A and Coveney A and Crystal J and Edwards GR} } @conference {3672, title = {Validation of an automated system for monitoring water intake and drinking behaviour in dairy calves}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {133-136}, address = {Rotorua}, abstract = {The provision of palatable drinking water ad libitum for cattle is often neglected on farm and is considered difficult and imprac-tical to monitor, particularly on an individual animal basis. The objective of this study was to validate an automated system for monitoring individual water intake and drinking behaviour of dairy calves. Nineteen dairy calves were observed over five days for eight hours/day. Calves were individually identified as they visited a water trough within a narrow chute where the number and duration of visits were recorded using an overhead photoelectric sensor, and water intake was recorded using a flow meter. Data from the automated system were compared to behavioural observations from video recordings across the same time period. The automated system was highly correlated with behavioural observations for both the number of visits (R2=0.96, P<0.001) and visit durations (R2=0.94, P<0.001), but showed no correlation for water intake (R2=0.01, P>0.1). This system could be used as a reliable automated method for recording drinking behaviour in terms of the number and duration of visits. However, alternative systems for measuring water intake need to be investigated and incorporated into the automated system. This information could be used to investigate a number of questions regarding water use and quality, and their effects on calf health and welfare and could be integrated into other automated systems used on farm for daily animal monitoring.}, issn = {1176-5283}, author = {Lowe GL and Sch{\"u}tz KE and Sutherland MA and Wilson MT and Stewart M} } @conference {3672, title = {Valuing improved deer genetics}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {117-120}, address = {Rotorua}, abstract = {New Zealand deer breeders have made rapid genetic progress in growth traits over the previous decade. A farm-systems analysis was performed using real growth data, to compare sires of differing breed-type and genetic merit for growth traits. Scenarios used red deer maternal sires, of average or high genetic merit, and wapiti terminal sires of high genetic merit. The base scenario of all average-genetic-merit maternal sires was compared against all other systems. Capital stock numbers were adjusted to maintain starting winter pasture covers and total average pasture covers to be as similar as possible; all other core parameters were kept consistent. All high-growth merit scenarios were 6.1\%-8.4\% more profitable. Median age to slaughter decreased by between 37-61 days, resulting in an increase in average sale value ($/kg) of 5.5\%-7.7\%. Average carcass weights increased by 2.7\%-4.2\% with an increase in efficiency (kg product/kg DM consumed) of 1.6\%-3.1\% over the base scenario. These gains in productivity, profit-ability and efficiency, relative to the base scenario were all achieved with reductions of between 5.6\% and 8.0\% in the capital hind base. This farm-systems analysis demonstrates that there are favourable gains to be made by deer farmers investing in genetics for improved growth traits.}, issn = {1176-5283}, author = {Ward JF and Thompson BR} } @conference {3672, title = {The welfare of bobby calves sent for slaughter: a synopsis of the science literature within the context of New Zealand{\textquoteright}s export system and the problems and gaps in it}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {149-153}, address = {Rotorua}, abstract = {Most neonatal animals are healthy and vigorous but vulnerable, particularly during the first week of life, to hypothermia and starvation, infections and injuries, and predation. Information collated from the scientific literature and routine ante-mortem in-spections indicates that the main factors predisposing bobby calves to death or condemnation are inadequate colostrum/feeding, and immaturity. Correct feeding regimes and transport protocols can minimise welfare compromises to healthy calves and most presented for slaughter were found to be strong, alert and well fed. However, small numbers of immature, weak, sick and injured calves were also presented. Dead or moribund calves had digestive tract disorders, umbilical infections or were undiagnosed. No curd in the rumen and immaturity were common secondary findings. What is less understood is the degree of hunger bobby calves may experience; the interaction between age/maturity, husbandry, feeding practices, transport and lairage; the limits of feed depri-vation in {\textquoteleft}marginal{\textquoteright} calves; compromises to welfare amongst those animals which do not die or are condemned prior to slaughter; and the impacts of any procurement and processing requirements for periods in lairage. }, issn = {1176-5283}, author = {Fisher MW and Wild RJ and O{\textquoteright}Grady KR and Guigou MJ and Diesch TJ and Jamieson JV and Ward LJ and Cross NJ} } @conference {3672, title = {BRIEF COMMUNICATION: A physiological evaluation of the efficacy of pain-mitigation strategies for cautery-disbudded goat kids}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {76}, year = {2016}, month = {07/2016}, pages = {106-108}, address = {Adelaide}, abstract = {Cautery disbudding is a painful procedure commonly performed on-farm to destroy the horn bud cells of goat kids to prevent horn growth. Disbudding is performed because horns can injure pen mates and stock people. Globally, standard practice of disbudding typically excludes the use of pain-mitigation and there are few studies investigating kid responses to disbudding and different pain-mitigation strategies. To date, pain-mitigation strategies used when disbudding kids include administration of non-steroidal anti-inflammatory drugs (NSAIDs), local anaesthesia (LA) and general anaesthesia (GA). Meloxicam (NSAID) reduced pain-related responses in cautery-disbudded kids (Ingvast-Larsson et al. 2011). Local anaesthetics (e.g., lignocaine), however, have not shown to be affective at reducing the pain response following disbudding (Alvarez et al. 2015). General anaesthesia has been used in kids, but its effect on pain-related responses was not assessed (Ingvast-Larsson et al. 2011). The objective of this study was to evaluate the physiological response to different painmitigation strategies for cautery-disbudding in goat kids.}, issn = {1176-5283}, author = {Hempstead MN and Stewart M and and Sutherland MA} } @conference {3672, title = {BRIEF COMMUNICATION: Ad libitum fodder-beet and pasture beef-finishing systems {\textendash} intake, utilisation, grazing behaviour and liveweight gains}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {76}, year = {2016}, month = {07/2016}, pages = {87-89}, address = {Adelaide}, abstract = {Traditionally, New Zealand (NZ) beef-production systems rely almost solely on pasture production. However, the seasonality of pasture growth, which affects quality and quantity, impacts the productivity of the system, with mean slaughter age of 26-36 months. In accelerated beeffinishing systems internationally, cereal grains are used to maintain energy intakes across the production cycle, at a lower cost than is possible in NZ. A recent NZ development in beef-production systems involves ad libitum intakes of fodder beet (FB; Beta vulgaris) with minimal supplement for 130 d from weaning to spring, and then 90 d of grazing on grass-based pasture before slaughter. This system, developed by Gibbs at Lincoln University, allows finishing of spring born animals at 12-18 months of age (Gibbs et al. 2015; Gibbs \& Saldias 2014a). Ad libitum intakes after appropriate transition to FB are critical to system profitability, and prevention of rumen acidosis (Gibbs \& Saldias 2014b). However, previous NZ crop-feeding experience with brassicas suggests that increased intakes require reduced utilisation of feed (Rugoho 2013). There is no published information on FB utilisation in ad-libitum systems, where high pasture residuals at 24 h post-allocation are used to ensure maximal intakes. Therefore, this study was designed to determine utilisation, grazing behaviour and intake patterns, and liveweight (LWT) gains, in steers grazing FB and then spring perennial ryegrass (Lolium perenne) and white clover (Trifolium repens) based pasture.}, issn = {1176-5283}, author = {Saldias B and Gibbs SJ} } @conference {3672, title = {BRIEF COMMUNICATION: An investigation of automated measures for assessing pain-induced distress in dairy calves}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {76}, year = {2016}, month = {07/2016}, pages = {103-105}, address = {Adelaide}, abstract = {Dairy calves are routinely disbudded using hot-iron cautery without pain relief in New Zealand, and studies have shown this procedure causes physiological and behavioural changes indicative of pain (Stafford \& Mellor, 2011). To evaluate the effectiveness of different pain mitigation strategies during routine husbandry procedures (e.g., disbudding), intensive physiological and/or behavioural studies are needed. The limitations of these measures are that the methods (e.g., blood sampling) can cause animal stress and analysis of behaviour video recordings is labour intensive. Automated, non-invasive measures of behaviour are now available, such as feeding behaviour provided by automatic calf feeding systems (ACF) and activity, recorded using accelerometers (e.g., Hobo data loggers). Feeding and lying behaviours are altered in calves in response to stress and/or pain during procedures such as hot-iron cautery disbudding (Graf \& Senn, 1999; Bates et al. 2015). It is well documented that this procedure causes significant pain. Therefore, the aim of this study was to determine if behavioural data collected from ACF and Hobo data loggers could be used as an indicator of paininduced distress in dairy calves.}, issn = {1176-5283}, author = {Sutherland MA and Lowe GL and Huddart FJ and Stewart M} } @conference {3672, title = {BRIEF COMMUNICATION: An update on genetic parameters for facial eczema tolerance in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {76}, year = {2016}, month = {07/2016}, pages = {43-45}, address = {Adelaide}, abstract = {Facial Eczema (FE) is a metabolic disease resulting from liver and bile-duct damage, caused by ingestion of the mycotoxin sporidesmin A, found in the spores of the fungus Pithomyces chartarum. Risk of FE is associated with temperature, humidity and dead leaf matter (Mitchell et al. 1959; Brook 1963; Di Menna \& Bailey 1973). While FE is predominantly prevalent in the North Island of New Zealand, climatic change projections indicate that there will be an increase in the geographical spread of the fungus and associated sporidesmin, resulting in FE spreading to regions that are currently unaffected (Dennis et al. 2014). Clinical FE is characterised by photosensitisation due to liver injury; however, reduced production (Smith 2000) and reproduction (Moore et al. 1983; Mcmillan et al. 1988; Morris et al. 1991) is also observed in both clinically and sub-clinically affected animals. The heritability of liver damage at slaughter post-sporidesmin challenge was estimated to be 0.42 {\textpm} 0.09 (Campbell et al. 1981). In the live animal, serum gamma glutamyltransferase (GGT) collected 2 to 3 weeks after sporidesmin challenge can be used as a measure of liver damage (Towers \& Stratton 1978). Romney FE selection lines, initially selected for resistance or susceptibility on the basis of liver damage, were established in 1975...}, issn = {1176-5283}, author = {Mcrae KM and Cullen NG and Amyes NC and PL Johnson} } @conference {3672, title = {BRIEF COMMUNICATION: Days to calving and intercalving interval in beef and dairy-beef crossbred cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {76}, year = {2016}, month = {07/2016}, pages = {31-33}, address = {Adelaide}, abstract = {One important attribute of a beef-breeding cow is the ability to wean a calf every year. Furthermore, an earlierborn calf is likely to be heavier at weaning and its dam has more opportunity to conceive again during the following breeding season. In a spring-calving system under the seasonal pastoral-grazing system in New Zealand, a 365- day intercalving interval is desirable. A normal gestation length is 280 days leaving 85 days for a cow to resume oestrous cycles and conceive again to maintain the 365- day calving interval. Literature estimates of the interval between calving and the first oestrous cycle post-calving are 53-82 days for mixed-aged beef-breeding cows and 81-95 days for first-lactation beef-breeding cows (Hickson et al. 2012; Knight \& Nicoll 1978; Morris et al. 1978; Smeaton et al. 1986), indicating that a 365-day calving interval is difficult to maintain.}, issn = {1176-5283}, author = {Morris ST and Hickson RE and Martin NP and Kenyon PR} } @conference {3672, title = {BRIEF COMMUNICATION: Do different grazing strategies affect pre-weaning calf growth rates?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {76}, year = {2016}, month = {07/2016}, pages = {119-121}, address = {Adelaide}, abstract = {Rearing replacement heifer calves is a labour-intensive and expensive component of dairy systems (Drackley 2008). Large numbers of replacement heifers are not meeting target live weights in New Zealand (McNaughton \& Lopdell 2012) which has implications for future milk production, fertility and subsequent longevity in the herd (Van Amburgh \& Tikofsky 2001). This paper reports results from the second year of a long-term experiment being conducted at Massey University that examines the impact of colostral status and liveweight gain of heifer calves fed different diets on subsequent milk production, fertility and longevity in the herd. Previous work (Cardoso et al. 2015) demonstrated no difference in pre-weaning liveweight gain of calves fed different levels of milk. The calves in that study ate surprisingly little meal. It was surmised that the exposure to frequent shifts onto fresh pasture stimulated intake of pasture, and removed the advantage of feeding calves higher levels of milk and supplementation with meal. Anecdotally, many calves when removed from rearing sheds to pasture are kept on the same paddocks as they are not a high priority for pasture allocation. Therefore, the aim of this experiment was further collection of colostral and Brix data as described by Coleman et al. (2015), and to compare pre-weaning growth rates of calves that are continually offered fresh pasture to those that are set stocked.}, issn = {1176-5283}, author = {Back PJ and Hickson RE and van Bouwel K and de Cock H and Verdurmen J and Sneddon NW and Laven RA} } @conference {3672, title = {BRIEF COMMUNICATION: Does Viagra protect fetal lambs against maternal pregnancy toxaemia?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {76}, year = {2016}, month = {07/2016}, pages = {172-174}, address = {Adelaide}, abstract = {Poor fetal growth is commonly caused by placental insufficiency. In sheep, multiple fetuses have relatively small placentae with fewer cotyledons than singletons, limiting blood flow to the placenta, especially in late gestation when fetal growth rate is highest. Factors that reduce fetal growth, such as maternal genotype, nutrition, age, parity, fetal number, or environmental temperature, typically reduce placental size and are associated with lower rates of fetal oxygen and nutrient uptakes and placental blood flow (Reynolds \& Redmer 2001). Further, circumstances that influence placental vascular development have a dramatic impact on fetal growth and development, and affect neonatal survival and growth (Borowicz et al. 2007; Satterfield et al, 2010). Sildenafil citrate (SC, trade names Viagra or Avigra) increases vasodilatation of uteroplacental vessels (Wareing et al. 2005) and may represent a novel therapy to improve fetal lamb growth. Sildenafil citrate has successfully increased birth weight in rodent models and singleton bearing ewes (Satterfield et al. 2010; Miller at al. 2009). There is no published information regarding the use of SC in multiple-bearing ewes. The objective of this trial was to determine if SC administration to triplet-bearing ewes in late gestation could increase lamb birth weight. In addition, the influence of SC on the incidence of pregnancy toxaemia is also reported here.}, issn = {1176-5283}, author = {Peterson SW and Pain SJ and McCoard SA and Oliver M and Baker PN and Kenyon PR and Blair HT} } @conference {3672, title = {BRIEF COMMUNICATION: Feed value of maize silage in New Zealand - a review}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {76}, year = {2016}, month = {07/2016}, pages = {100-102}, address = {Adelaide}, abstract = {Maize silage is a major dietary component for dairy cows in the USA and Germany with average feeding rates of 2.7 and 4.1 tDM per cow per year respectively (Table 1). Maize silage usage in NZ has increased over the past two decades. It currently accounts for approximately 6\% of feed energy supplied to the national herd, calculated using national herd energy requirements (based on cow numbers and milk processed 2013/14 in NZ (New Zealand Dairy Statistics 2013/14)) and the amount of maize silage harvested (AIMI 2015). It is important to establish maize silage feed quality in NZ to better understand its potential to support pasture based farms. Published NZ research has measured in-vivo digestibility of maize silage in animal trials (Kirley 1977; Smith 1973); however, the number of trials is limited and they were not performed using standard protocols to allow pooling of data. The aim of this paper was to compare the nutrient composition of overseas and NZ maize silage to determine if overseas in-vivo energy measurements are applicable to local maize silage and to determine how well NZ maize silage kernel is processed.}, issn = {1176-5283}, author = {Kleinmans JJ and Densley RJ and Hurley T and Williams ID and Calbert F} } @conference {3672, title = {BRIEF COMMUNICATION: Immediate removal of dairy goat kids from the doe as a strategy to manage colostrum intake}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {76}, year = {2016}, month = {07/2016}, pages = {169-171}, address = {Adelaide}, abstract = {An impeded transfer of antibodies between the maternal and fetal circulatory system results in goat kids lacking immunity at birth (Hurley \& Theil 2011). The dam{\textquoteright}s colostrum, which supplies energy, nutrients and growth hormones, also passively provides immunity via immunoglobulin G (IgG) (Hurley \& Theil 2011). Without colostrum, morbidity and mortality increases (O{\textquoteright}Brien \& Sherman 1993). Unfortunately, colostrum is also a source of disease, such as caprine arthritis-encephalitis (CAE) (Reina et al. 2009). Therefore, removal of the offspring prior to maternal colostrum transfer is often practiced (Reina et al. 2009) because it allows for feeding alternative, disease-free colostrum. For goats, colostrum alternatives include: bovine, heat-treated caprine, and artificial bovinebased replacer. While incorrect heat-treatment can reduce IgG content (Tyler et al. 2000) and some artificial replacers fail to improve immunity acquisition (Constant et al. 1994), few adverse effects (e.g. reduced kid survival) of these alternatives have been noted (MacKenzie et al. 1987; Moretti et al. 2012). Worldwide, farmers are attempting kid removal and alternative colostrum feeding, but it is not known to what extent this practice occurs, nor how successful farmers are at preventing colostrum ingestion from the doe. Since bovine and caprine IgG can be measured in serum, presence or absence of either can help determine the colostrum type ingested. Therefore, the objectives of this study were to: 1) determine the prevalence of immediate kid removal, and 2) compare the farmer-reported percentage of kids successfully removed to the percentage of kids with caprine serum IgG (an indicator of doe colostrum ingested).}, issn = {1176-5283}, author = {Zobel G and Tan BL and Deeming L} } @conference {3672, title = {BRIEF COMMUNICATION: Impact of date of birth recording practises in genetic evaluation in New Zealand sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {76}, year = {2016}, month = {07/2016}, pages = {59-61}, address = {Adelaide}, abstract = {Accuracy of selection is an important feature for all breeding programs and genetic evaluation systems, with genetic gain influenced by the accuracy of the breeding values and by the selection decisions taken by the breeder. Accuracy of estimated breeding values (eBVs) are affected by the amount and quality of the pedigree and performance data recorded. With increasing use of breeding values based on across{\textendash}flock analyses, the impact of various data recording practises used in sheep flocks needs investigation to ensure practises by any particular breeder do not adversely affect the whole analysis.}, issn = {1176-5283}, author = {McIntyre S and Newman S-AN} } @conference {3672, title = {BRIEF COMMUNICATION: Plasma amino acid profiles of lactating dairy cows fed fodder beet and ryegrass diets}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {76}, year = {2016}, month = {07/2016}, pages = {62-64}, address = {Adelaide}, abstract = {In pastoral systems, N intake by dairy cows generally exceeds requirements (Kolver 2000). Feeds with low N concentration can {\textquoteleft}dilute{\textquoteright} the amount of N eaten by grazing dairy cattle, and ultimately reduce N pollution of the environment. Use of fodder beet (FB) crop has increased substantially in New Zealand because of its high DM yield potential. Fodder beet also has low N content in the bulb of the plant (0.8 to 1.5\% of DM; Heuz{\'e} et al. 2015) which is useful for diluting dietary N content. However, these low N concentrations could result in deficiencies of specific amino acids (AA), potentially limiting milk production. This paper reports the effect on plasma AA concentrations of partial replacement of ryegrass pasture with FB in the diet of lactating dairy cows. This information will provide insights on how low-N diets could impact nutrient supply to dairy cattle.}, issn = {1176-5283}, author = {Pacheco D and Waghorn G and Dalley DE} } @conference {3672, title = {BRIEF COMMUNICATION: Preliminary estimates of genetic parameters for adult dag scores in New Zealand sheep and their relationship with juvenile measurements}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {76}, year = {2016}, month = {07/2016}, pages = {144-145}, address = {Adelaide}, abstract = {The accumulation of faecal material around the breech area of sheep (dags) is of interest to the New Zealand sheep industry for a variety of reasons, including financial penalties for presenting animals with dags at slaughter, reduced wool value, increased risk of flystrike and the labour cost associated with dagging both lambs and adult ewes (Pickering et al. 2012). Currently, dag scores at both three (DAG3) and eight (DAG8) months of age are routinely measured, and analysed in Sheep Improvement Limited (SIL). However, there are currently no formally published estimates of the genetic relationship between dag score as a lamb and dag score as an adult (DAGA) in the New Zealand sheep population. Adult dag score has been found to be highly repeatable between 12 months to two years of age (R = 0.42) and between two and three years of age (R = 0.44) in different strains of Merino sheep (Larsen et al. 1995). Currently within SIL, the estimated breeding values (EBVs) calculated from DAG8 measures are reported as the adult dag score EBVs. There are now, however, multiple flocks recording adult dag score in the SIL database. An analysis of the correlation of adult dag score with DAG8 and DAG3 would confirm if the current SIL model is appropriate for reporting adult dag EBVs, or if the model needs revising to include adult dag measures and its correlations with DAG3 and DAG8.}, issn = {1176-5283}, author = {Mcrae KM and Dodds KG and Newman S-AN and Brito LF and Pickering NK and McEwan JC} } @conference {3672, title = {BRIEF COMMUNICATION: The effect of milk allowance on performance of dairy calves}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {76}, year = {2016}, month = {07/2016}, pages = {175-176}, address = {Adelaide}, abstract = {Restricted milk diets increase and hasten the onset of solid feed intake in milk-fed calves (de Passill{\'e} et al., 2011) and facilitate the weaning of calves, which reduces the growth check during weaning in comparison to ad libitum fed calves (Huuskonen \& Khalili, 2008). As a consequence, dairy calves are commonly fed a restricted milk allowance of approximately 10\% of a calf{\textquoteright}s BW (approximately 4 to 6 L of milk/d; e.g. Vasseur et al., 2012). However, calves fed a restricted amount of milk (10\% of BW) show increased behavioural signs of hunger like non-nutritive visits to the milk feeder (Rushen \& de Passill{\'e}, 1995) and less growth pre-weaning when compared with calves fed more milk (Khan et al., 2007). Indeed, a growing body of research has consistently shown that calves fed more milk exhibit greater BW gains before weaning (see review by Khan et al., 2011). The aim of this study was to identify the effect of feeding 6 or 12 L/d of milk on average daily gain (ADG) and final body weight (BW) after weaning when using a gradual, step-down weaning method.}, issn = {1176-5283}, author = {Rosenberger K and Costa JHC and Neave HW and vonKeyserlingk MAF and Weary DM} } @conference {3672, title = {BRIEF COMMUNICATION: The use of farm-management tools by New Zealand sheep farmers: changes with time}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {76}, year = {2016}, month = {07/2016}, pages = {78-80}, address = {Adelaide}, abstract = {The utilisation of farm-management tools by New Zealand sheep farmers can support on-farm decision making, thus facilitating improvements in productivity and profitability of the farming enterprise. There are numerous management tools available to farmers, for example, a recent report identified 127 tools that were available to New Zealand farmers (Allen \& Wolfert 2011). Although a large number of tools are accessible to farmers, a survey of sheep farmers conducted in 2012 by Corner-Thomas et al. (2015) identified many that were utilised by only a small percentage of farmers. This indicates that there is the potential for increased uptake of management tools which, if relevant, may lead to benefits in on-farm productivity. The aim of the current study was to determine for sheep farmers in New Zealand, if use of farm-management tools had changed over a two-year period.}, issn = {1176-5283}, author = {Corner-Thomas RA and Kenyon PR and Morris ST and Ridler AL and Hickson RE and Greer AW and Logan CM and Blair HT} } @conference {3672, title = {BRIEF COMMUNICATION: The use of infrared thermography and feeding behaviour for early disease detection in New Zealand dairy calves}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {76}, year = {2016}, month = {07/2016}, pages = {177-179}, address = {Adelaide}, abstract = {Neonatal calf diarrhoea (NCD) is a disease impacting livestock industries economically and in terms of animal health and welfare. In New Zealand, the most prevalent pathogens associated with NCD are rotavirus and Cryptosporidium (Mawly et al. 2015), but other common pathogens include coronavirus and Salmonella. By the time an animal presents with clinical signs of disease, much of the associated tissue damage to the intestinal submucosa may have already occurred, hence affecting production. Therefore, there is a need to develop methods for early disease detection, which ideally could be incorporated into automated systems for real-time, remote sensing. Infrared thermography (IRT) is a non-invasive method of detecting radiated heat. The use of IRT in livestock and veterinary applications was reviewed by Luzi et al. (2013). Studies have shown IRT can be used for early identification of calves with BRD (bovine respiratory disease) and BVD (bovine viral diarrhoea), using changes in eye temperature (Schaefer et al. 2004, 2012). Schaefer et al. (2012) demonstrated that images could be collected automatically at a water trough. In dairy calves, the behavioural information (e.g. number of visits) gathered remotely at an automatic calf-feeding (ACF) system can be used for identification of at risk animals (Svensson \& Jensen, 2007; Borderas et al. 2009). However, the use of these automated systems has not been fully investigated under New Zealand conditions, where calves are exposed to different pathogens and management.}, issn = {1176-5283}, author = {Lowe GL and Schaefer AL and and Wilson MT and Sutherland MA and Stewart M} } @conference {3672, title = {BRIEF COMMUNICATION: Variability in growth rates of goat kids on 16 New Zealand dairy goat farms}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {76}, year = {2016}, month = {07/2016}, pages = {137-138}, address = {Adelaide}, abstract = {Average daily weight gains (ADG) in early life are associated with health, welfare and future production potential of dairy animals. While this has yet to be established for goats, research in cows demonstrates a positive relationship between growth in early life and milk production (Shamay et al. 2005, Soberon et al. 2012). Early growth rates are largely determined by the management practices from birth onwards. It is therefore unsurprising that large differences in ADG under different management systems have been reported. In lambs, Mahgoub et al. (2000) reported a large range in ADG (84-154 g/day). Similarly, in calves, Bartlett et al. (2006) reported ADGs ranging from 251 g/day to 703 g/day. The ADGs reported in goats have not been as variable (152-170 g/day: Galina et al. 1995; 167-173 g/day: Goetsch et al. 2001); however, these were small, controlled studies. To our knowledge, no research has yet quantified variability in the ADG of goat kids on a large, multi-farm scale. Therefore, the aim of this study was to describe the variation in growth rates on multiple dairy goat farms in the Waikato region of NZ, providing a benchmark for dairy goat farmers.}, issn = {1176-5283}, author = {Deeming LE and Beausoleil NJ and Stafford KJ and Webster JR and Zobel G} } @conference {3672, title = {BRIEF COMMUNICATION: Which traits best predict ewe performance and survival the following year on a UK hill farm?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {76}, year = {2016}, month = {07/2016}, pages = {159-162}, address = {Adelaide}, abstract = {Increasing ewe longevity and reproductive output can improve whole-flock efficiency and reduce environmental impact (Jones et al. 2013). By increasing ewe longevity (the length of productive life), fewer replacements are required, reducing the number of unproductive animals and increasing the number of ewe lambs to sell (Dickerson \& Glimp 1975). Longevity research often looks for genetic indicators of this trait; however, heritability is low, or occasionally moderate (Mekkawy et al. 2009). An alternative approach may be to alter how animals are retained for breeding the following year, allowing animals to reach their potential and not reducing longevity by selling animals that are still productive. To achieve this, it is essential to be able to identify ewes that will survive and be productive. Although most research on longevity concentrates on the whole lifetime of an animal, it may be informative to consider factors that affect just the following years{\textquoteright} performance, in order to aid retention decisions, particularly when genetic information is unavailable.}, issn = {1176-5283}, author = {Wishart HM and Lambe NR and Morgan-Davis C and Waterhouse A} } @conference {3672, title = {DEERSelect {\textendash} review of the first decade}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {76}, year = {2016}, month = {07/2016}, pages = {54-58}, address = {Adelaide}, abstract = {DEERSelect, the New Zealand deer industry performance recording system, has been operating since 2005 in red deer. Over that period, the role and functionality of DEERSelect has grown, such that it is now central to all genetic information delivery to the industry. Initially velvet and growth trait modules were included, with meat and reproduction trait modules added later. Economic indexes were also developed, but have not been widely utilised. Evaluations were added for wapiti, to provide for all breed types. Current desires are for wapiti and red deer to be combined in a single evaluation. Good genetic gains have been made, primarily in growth traits. Impetus provided by the Deer Progeny Test (DPT), and increased breeder education has improved understanding of best practice recording, leading to better data quality and herd connectedness. While DEERSelect is recognised by industry leaders as being critical for genetic advancement, it still has limited stag-buyer adoption. Improved adoption will require a large extension effort so commercial producers can interpret the impacts of breeding values in terms of changes in farm system performance and profitability. The future is promising, with new traits, improvements on existing ones and breeders now valuing objective measures of genetic merit.}, issn = {1176-5283}, author = {Ward JF and McIntyre SB and Newman S-AN and Asher GW} } @conference {3672, title = {Development and evaluation of a temperament-scoring system for farmed deer: genetic and environmental components}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {76}, year = {2016}, month = {07/2016}, pages = {109-103}, address = {Adelaide}, abstract = {A temperament-scoring system for farmed red deer was developed and evaluated. Hinds (n=1102) and their progeny (n=1609) from three farms were repeatedly scored (7867 observations in total) for aggression, agitation in a pen or when confined in a crate, ease of handling, and exit speed from a crate. The animals were scored when yarded for management procedures by one handler. Inter-observer reliability recorded on a separate occasion was between 70 and 82\%, measured as percentage agreement. For progeny, heritability was for aggression:0.03{\textpm}0.024, agitation (pen):0.23{\textpm}0.077, agitation (crate):0.17{\textpm}0.056, ease of handling:0.10{\textpm}0.037, and exit speed:0.04{\textpm}0.021, with a repeatability of 0.19{\textpm}0.018, 0.24{\textpm}0.022, 0.25{\textpm}0.017, 0.24{\textpm}0.015, and 0.17{\textpm}0.013, respectively (estimate{\textpm}SE of estimate for all preceding values). For hinds, repeatability was for aggression:0.23{\textpm}0.048, agitation (pen):0.16{\textpm}0.068, agitation (crate):0.38{\textpm}0.052, ease of handling:0.45{\textpm}0.048, and exit speed:0.27{\textpm}0.061 (estimate{\textpm}SE of estimate), respectively. Animals that were agitated in a pen were also more agitated in a crate (r=0.352 and 0.479 for progeny and hinds, respectively), all other associations were weak (r<=0.228). Farm, year born, age, and drafting order, but not sex, influenced most temperament scores. Temperament of red deer can reliably be scored in a yard. Agitation showed a moderate genetic component and could, therefore, be included in future breeding programmes.}, issn = {1176-5283}, author = {Sch{\"u}tz KE and Ward JF and Cox NR and Asher GW} } @conference {3672, title = {Dietary preference of dairy cows for perennial ryegrass cultivars growing with and without white clover}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {76}, year = {2016}, month = {07/2016}, pages = {81-86}, address = {Adelaide}, abstract = {Dietary preference of dairy cows for eight perennial ryegrass cultivars (AberMagic, Alto, Base, Bealey, Commando, Kamo, One50 and Prospect) growing with and without white clover was examined at two vegetative stages (May and October) and one reproductive stage (November). Groups of dairy cows (n = 8) were offered free choice among cultivars growing with or without white clover for 6 to 8 hours. Preference was defined as the relative decreasing rate in sward surface height. Preference was higher for the tetraploid cultivars, Base and Bealey and the high-sugar diploid cultivar, AberMagic (preference ranged from 1.02 to 1.45). Preference was negatively correlated with herbage mass (r = -0.179, P = 0.013), proportion of dead material (r = -0.301, P < 0.001) and neutral detergent fibre (r = -0.287, P < 0.001), and positively correlated with sward surface height (r = 0.386, P < 0.001), ryegrass lamina length (r = 0.233, P = 0.001), tiller mass (r = 0.338, P < 0.001), water-soluble carbohydrate concentration (r = 0.143, P = 0.049) and organic matter digestibility in dry matter (r = 0.312, P < 0.001). Although the proportion of white clover was low (< 7\% DM) in all three experiments, the interactions between perennial ryegrass cultivar and the presence of white clover were significant (P = 0.004 at pre-heading stage, P = 0.046 at reproductive stage and P = 0.038 at post-heading stage), with differences among preference for perennial ryegrass cultivars reduced when white clover was present}, issn = {1176-5283}, author = {Chen A and Bryant RH and Edwards GR} } @conference {3672, title = {Does ewe nutrition during pregnancy affect the neonatal behaviour of twin-born lambs?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {76}, year = {2016}, month = {07/2016}, pages = {8-13}, address = {Adelaide}, abstract = {In this experiment the effects of feeding treatments from mid pregnancy until lambing on the behaviour of twin-bearing ewes and their lambs were investigated. Fifty seven four-year-old Romney ewes were offered a medium (1164 {\textpm} 31.6 and 819 {\textpm} 16.0 kg DM/ha pre- and post-grazing pasture mass, respectively) or ad libitum (2181 {\textpm} 47.6 and 1431 {\textpm} 24.6 kg DM/ha pre- and post-grazing pasture mass, respectively) feeding treatment from day 76 of pregnancy until after lambing. At ear-tagging the time taken for the lambs to stand, make contact with, suck from and follow their dam was recorded. A maternal behaviour score based on the distance the ewe moved away from her lambs during tagging was also recorded. Survival analysis showed that lambs born to ewes offered the medium feeding treatment from mid pregnancy until lambing were quicker to stand, suck and follow compared with lambs born to ewes offered the ad libitum feeding treatment (P<0.05). It is unclear whether these behaviours indicate that lambs born to ewes in the medium treatment were more vigorous or that they had unmet needs that prompted the apparent increase in vigour. Ewe feeding treatments did not affect the maternal behaviour of the ewes.}, issn = {1176-5283}, author = {Gronqvist GV and Hickson RE and Corner-Thomas RA and Kenyon PR and Stafford KJ and Morris ST} } @conference {3672, title = {Does mowing before grazing increase dry matter intake and milk yield?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {76}, year = {2016}, month = {07/2016}, pages = {73-77}, address = {Adelaide}, abstract = {Mowing pasture before allocation of herbage to dairy cows is one management strategy suggested to improve feed quality, increase herbage dry matter (DM) intake and increase milk solids yield. To test these hypotheses, pasture at either a three or four week regrowth interval was offered to dairy cows 3 hours after pasture had been mown or as standing pasture. Forty-eight late lactation, Friesian x Jersey dairy cows were blocked into four groups and randomly allocated to each treatment. There was no effect of mowing or regrowth interval on botanical composition of the pasture on offer. Composition of herbage above 3.5 cm varied in DM content which was increased by mowing (13.2 versus 18.4\% DM, P<0.05). For pastures with a three week regrowth interval, crude protein content was higher in the mown compared with standing herbage. At a similar herbage allocation, apparent DM intake was lower in mown (14.9 kg DM/cow/day) than in standing (15.5 kg DM/cow/day) treatments (P<0.05). This resulted in lower milk solids yield (P<0.05) in mown (1.24 MS/cow/day) compared with standing pasture (1.40 kg MS/cow/day). There was no apparent advantage in mowing ryegrass pastures in late lactation to improve herbage utilisation, DM intake or milk yield.}, issn = {1176-5283}, author = {Bryant RH and Kingsbury LA and Edwards GR} } @conference {3672, title = {Effect of grazing system on nitrogen partitioning in lactating dairy cows grazing irrigated pastures in Canterbury, New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {76}, year = {2016}, month = {07/2016}, pages = {94-99}, address = {Adelaide}, abstract = {Regulations currently being developed by Regional Councils throughout New Zealand to manage freshwater quality may require substantial reductions in nitrate leaching from dairy farms in many regions. The objective of this study was to quantify nitrogen intake, partitioning, and excretion in two irrigated farming systems in Canterbury, comparing different possible pathways for future industry development. A {\textquoteleft}higher input{\textquoteright} system (HI, n = 34 cows) was characterised by a stocking rate of 5 cows per/ha, ~300 kg/ha/year fertiliser N and ~1t DM/cow/year purchased supplement fed on the milking platform. The {\textquoteleft}lower input{\textquoteright} system (LI, n = 29 cows) used a stocking rate of 3.5 cows/ha, 150 kg/ha/year fertiliser N, and minimal purchased supplement. Urine, faeces, plasma, and milk samples were collected for N determination at consecutive afternoon and morning milkings once per month for four years. Estimated N intake did not differ between HI and LI (537 g N/cow/day and 557 g N/cow/day respectively, P = 0.29). No differences were recorded for N parameters and estimated milk and urine N output/cow was not affected by farm system. When scaled to per hectare, urinary N excretion was 33\% greater for HI compared with LI (1.1 kg/ha/day and 0.8 kg/ha/day, respectively, P = 0.02).}, issn = {1176-5283}, author = {Clement AR and Dalley DE and Chapman DF and Edwards GR and Bryant RH} } @conference {3672, title = {Estimation of genetic parameters for milk yield traits at different herd production levels in cows milked once- or twice-daily in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {76}, year = {2016}, month = {07/2016}, pages = {49-53}, address = {Adelaide}, abstract = {The objective of this study was to estimate genetic parameters for lactation yields of milk (MY), fat (FY) and protein (PY) for cows milked either once- (OAD) or twice-a-day (TAD) at different production levels (PL), calculated as average milk solids yield (FY + PY) for dairy cattle in New Zealand. Lactation records of 124,620 and 194,631 cows from 298 and 350 herds milked OAD and TAD, respectively were used. Heritiabilities (h2) were lower in low PL herds milked OAD compared to low PL herds milked TAD (0.11-0.18 vs. 0.22-0.37). Across PL, h2 for MY at medium and high PL were greater than 0.30 at both MF, while for FY and PY, those values were less than 0.30. Genetic correlations (rG) between MY and PY were greater (>0.70) compared to rG between FY and any of the other traits (<0.65). The lowest rG was observed between MY and FY at low PL (0.09{\textpm}0.087). In conclusion, lower h2 at low PL from cows milked OAD reveal unequal genetic expression of milk traits genes compared to higher PL. Ignoring the heterogeneity of variance in the genetic evaluation could result in systematic inaccuracies and biases in the estimation of breeding values for cows milked OAD.}, issn = {1176-5283}, author = {Lembeye F and Lopez-Villalobos N and Burke JL and Davis SR} } @conference {3672, title = {Genetics of alternative definitions of feed efficiency in grazing lactating dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {76}, year = {2016}, month = {07/2016}, pages = {38-42}, address = {Adelaide}, abstract = {There has been anecdotal evidence of increasing liver abscessation on bull-beef farms across New Zealand from meat processors for more than a decade, but to date, no quantitative data has been published in the field. This study objective was to establish the incidence of liver abscessation in pasture- based beef bulls, the seasonality and breed differences, the impact on carcass weight, and to compare this with published data from feedlot cattle internationally. The study used a database of 137675 bulls slaughtered in the South Island between 2000-2005. The database included breed, farm location, carcass weight, liver abscess presence and abscess grading score (absent, mild, moderate, severe). The annual incidence of liver abscessation calculated was a mean of 9.5\%. This recorded value is greater than other observed incidences from pasture-based systems and reduced compared with those observed in non-medicated feedlot systems internationally. There were significant variations in all measured parameters across years, and a clear and significant seasonal variation was observed. Incidence of liver abscessation peaked across November- December (11.3 and 11\% respectively) and then declined as the slaughter season progressed. The typical NZ beef industry approach to rearing bulls for slaughter makes it likely that age at slaughter is a key influence on the seasonal incidence rate, with most cattle born in spring and slaughtered after 18 months, suggesting the late spring and summer peak in incidence is due to bulls older than two years. The percentages of abscesses graded were: severe (66.4\%), moderate (12.8\%), and mild (20.7\%). Friesian and dairy crossbreed bulls had an incidence approximately twofold greater than that females beef breeds (10.3\% and 4.7\% respectively). There was a significant difference in the mean carcass weights of bulls graded, with those moderate with abscessation having a mean heavier carcass weight than those graded severe, minor and no abscess.}, issn = {1176-5283}, author = {Hurley AM and Lopez-Villalobos N and McParland S and Lewis E and Kennedy E and O{\textquoteright}Donovan M and Burke JL and Berry DP} } @conference {3672, title = {Grazing behaviour and species selection of heifer calves fed different forages.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {76}, year = {2016}, month = {07/2016}, pages = {126-131}, address = {Adelaide}, abstract = {

The aim of this experiment was to determine whether there was a difference in the behaviour of calves grazing different forages. Weaned dairy heifer calves (n = 64) were assigned to two different forage feeding treatments: ryegrass pasture and a clover-herb mix. Behavioural observations were recorded every 10 minutes over a 72 h period. Behaviours recorded were standing, walking, lying or sitting, grazing, ruminating, drinking/grooming, playing and various combinations of these. Calves grazing pasture spent more time lying and ruminating compared to calves grazing the clover-herb mix (34.6\% vs 16.7\%), and less time standing and grazing (17.2\% vs 32.2\%). Calves were less active from late evening and early morning and more likely to be ruminating earlier in the day and grazing later in the day. Plant selection (measured as plant disappearance rate) was determined in calves grazing the clover-herb mix. Red clover had the highest disappearance rate on all days compared to other species (P\<0.05). Plantain, chicory and white clover eaten on day one did not differ in proportions eaten, but by day three less red clover and chicory remained compared to plantain and white clover (P\<0.05).

}, issn = {1176-5283}, author = {Back PJ and Hickson RE and Lilly VM and Coleman LW and Sneddon NW and Laven RA} } @conference {3672, title = {Growth of early weaned lambs on a plantain-clover mix compared with lambs suckling their dam on a plantain-clover mix or a grass based sward}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {76}, year = {2016}, month = {07/2016}, pages = {65-68}, address = {Adelaide}, abstract = {Plantain-clover mixes have high metabolisable energy content and have been shown to support greater liveweight gains in lambs both pre- and post-weaning when compared with grass. The aim of this experiment was to determine if a plantain-clover mix could be used as a means to wean lambs earlier. Twin-bearing ewes (n=67) with both lambs at a minimum live weight of 16 kg each were allocated to one of three treatments; 1) ewe and lambs together on grass, 2) ewes and lambs together on plantain- clover mix, 3) lambs weaned at approximately 8 weeks of age onto a plantain-clover mix and ewes on grass. Lambs that were weaned early were lighter (P<0.05) at approximately 14 weeks of age than those which remained with their dam on either a plantain-clover mix or grass (32.3{\textpm}0.43 vs 34.7{\textpm}0.44 vs 33.7{\textpm}0.45 kg, respectively). However, ewes which had their lambs weaned early were heavier (P<0.05; 79.7{\textpm}1.73 vs 75.5{\textpm}1.68 vs 75.9{\textpm}1.64 kg, respectively) and in better body condition score (P<0.05; 3.1{\textpm}0.05 vs 2.9{\textpm}0.05 vs 2.9{\textpm}0.05, respectively) than those which remained with their lambs on either a plantain-clover mix or grass. This suggests early weaning improved ewe condition but did not improve lamb performance}, issn = {1176-5283}, author = {Cranston LM and Corner-Thomas RA and Kenyon PR and Morris ST} } @conference {3672, title = {The impact of lamb growth rate pre- and post-weaning on farm profitability in three geoclimatic regions}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {76}, year = {2016}, month = {07/2016}, pages = {132-136}, address = {Adelaide}, abstract = {Sheep and beef farmers target an increase in lamb growth rates as a means of increasing on-farm profit. Increasing any performance parameter invariably increases feed demand, resulting in either a need to increase feed supply or reduce feed demand in some other area of the farm system, therefore potentially affecting profit. A whole-farm-system model was used to assess the impact of increasing lamb weaning weight and post-weaning growth rate on farm profit and enterprise selection of three farms from three regions (Otago, Gisborne and Northland). Farm profit did not always increase with an increase in weaning weight or post-weaning growth rate. Farm profit was highest in the cool temperate region when weaning weight was at the base weight (27 kg) and post-weaning growth rate was 75 g/d greater than current. Farm profit was highest in the dry temperate region when weaning weight was 32 kg (6 kg above the base weight) and post-weaning growth rate was 50 g/d greater than the base growth profile. In the warm, temperate region, farm profit was highest at the two extremes, the highest weaning weight (30.6 kg) and post-weaning growth rate profile (100 g/d greater than the base profile) and at the lowest weaning weight (24.6 kg) and post-weaning growth rate profile (50 g/d less than the base profile). This demonstrates the interactions and trade-offs between feed supply and lamb growth rate on farm, and highlights that increasing lamb liveweight gain does not necessarily equate to increased profit.}, issn = {1176-5283}, author = {Thompson BR and Stevens DR and Scobie DR and O{\textquoteright}Connell D} } @conference {3672, title = {The incidence of liver abscessation in slaughtered beef bulls in the South Island of New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {76}, year = {2016}, month = {07/2016}, pages = {114-118}, address = {Adelaide}, abstract = {There has been anecdotal evidence of increasing liver abscessation on bull-beef farms across New Zealand from meat processors for more than a decade, but to date, no quantitative data has been published in the field. This study objective was to establish the incidence of liver abscessation in pasture- based beef bulls, the seasonality and breed differences, the impact on carcass weight, and to compare this with published data from feedlot cattle internationally. The study used a database of 137675 bulls slaughtered in the South Island between 2000-2005. The database included breed, farm location, carcass weight, liver abscess presence and abscess grading score (absent, mild, moderate, severe). The annual incidence of liver abscessation calculated was a mean of 9.5\%. This recorded value is greater than other observed incidences from pasture-based systems and reduced compared with those observed in non-medicated feedlot systems internationally. There were significant variations in all measured parameters across years, and a clear and significant seasonal variation was observed. Incidence of liver abscessation peaked across November- December (11.3 and 11\% respectively) and then declined as the slaughter season progressed. The typical NZ beef industry approach to rearing bulls for slaughter makes it likely that age at slaughter is a key influence on the seasonal incidence rate, with most cattle born in spring and slaughtered after 18 months, suggesting the late spring and summer peak in incidence is due to bulls older than two years. The percentages of abscesses graded were: severe (66.4\%), moderate (12.8\%), and mild (20.7\%). Friesian and dairy crossbreed bulls had an incidence approximately twofold greater than that females beef breeds (10.3\% and 4.7\% respectively). There was a significant difference in the mean carcass weights of bulls graded, with those moderate with abscessation having a mean heavier carcass weight than those graded severe, minor and no abscess.}, issn = {1176-5283}, author = {Trotter CG and Gibbs SJ} } @conference {3672, title = {The influence of age and breed of cow on colostrum indicators of suckled beef calves}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {76}, year = {2016}, month = {07/2016}, pages = {163-168}, address = {Adelaide}, abstract = {Rearing a calf to weaning is a key measure of performance in a beef breeding cow herd. Adequate intake of colostral antibodies by the calf in the first few hours of life is important for passive transfer of immunity, and so is beneficial for calf survival. This experiment aimed to examine the role of udder conformation, maternal age and breed-cross on the colostral status of suckled calves. Udder conformation of Angus, Angus-cross-Friesian, Angus-cross-Jersey and Angus-cross-Kiwicross cows was scored according to Animal Evaluation Limited and BreedPlan standards, and colostral status of calves was determined based on gamma glutamyltransferase activity, immunoglobulin G and total protein concentrations at 24-48 hours of age. Udder conformation was similar (P>0.05) among breed-crosses except Angus cows had looser front udder attachment, lower rear udder attachment and less desirable udders overall than Angus-cross-dairy cows (P<0.05). Most udder conformation scores did not affect colostral status of calves. The exception was teat placement score, for which more outward-pointing teats were associated with improved colostrum status of calves (P<0.05). Survival to weaning was greater for calves with adequate compared with inadequate colostral status (P<0.001).}, issn = {1176-5283}, author = {Hickson RE and Back PJ and Martin NP and Kenyon PR and Morris ST} } @conference {3672, title = {The influence of previous reproduction on subsequent fertility in multiparous ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {76}, year = {2016}, month = {07/2016}, pages = {155-158}, address = {Adelaide}, abstract = {Adult ewes often lose live weight while lactating, but should regain it prior to the following mating if pasture availability or sheep numbers are managed judiciously. Data from a self-replacing flock of Wiltshire ewes four to nine years of age (n=267) was available for 622 lambing events across a 13-year period. Wiltshires grow little wool and live weight was not complicated by fleece weight. The average number of lambs born was 1.76 per ewe per year during the course of the study. Ewes not rearing a lamb (13.2\%), or rearing singles (42.4\%), twins (42.4\%), or triplets (1.9\%), were present at weaning. All ewes were grazed together and when their lambs were weaned, those that did not raise a lamb (67.4 {\textpm} 9.7 kg) were heavier than ewes that raised singles (63.0 {\textpm} 9.3 kg), twins (59.9 {\textpm} 8.5 kg) or triplets (59.7 {\textpm} 7.7 kg) (P<0.001). Despite this, the previous number of lambs weaned did not influence the number of lambs born in the subsequent year (P = 0.43), but was positively associated with ewe liveweight gain between weaning and mating (P<0.01). Number of lambs born was positively influenced by ewe live weight at mating up to 65 kg. Reproductive performance was not influenced by the previous year, providing ewes were able to increase live weight between weaning and mating.}, issn = {1176-5283}, author = {Scobie DR and O{\textquoteright}Connell D and Noble A and Greer AW} } @conference {3672, title = {Milk production and urinary nitrogen excretion of dairy cows grazing perennial ryegrass-white clover and pure plantain pastures}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {76}, year = {2016}, month = {07/2016}, pages = {18-21}, address = {Adelaide}, abstract = {Milk production and urinary nitrogen (N) concentration were measured in late lactation dairy cows grazing a perennial ryegrass- white clover pasture, pure plantain and an area that is comprised of 50\% perennial ryegrass-white clover and 50\% pure plantain by ground area (50-50 pasture-plantain), (n=12). Milksolids production was greater (P=0.01) for cows grazing plantain (1.67 kg MS/cow/d) than those grazing pasture (1.50 kg MS/cow/d), with cows grazing 50-50 pasture-plantain intermediate (1.60 kg MS/cow/d). Urine-N concentration was 56\% lower (P<0.001) for plantain (2.4 g N/L) and 33\% lower for 50-50 pasture-plantain (3.6 g N/L) than pasture (5.4 g N/L). Plantain may offer environmental benefits to dairy systems by reducing the urinary N concentration deposited on the soil from grazing cows in late lactation.}, issn = {1176-5283}, author = {Box LA and Edwards GR and Bryant RH} } @conference {3672, title = {More dairy heifers are achieving liveweight targets}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {76}, year = {2016}, month = {07/2016}, pages = {3-7}, address = {Adelaide}, abstract = {Dairy heifers should reach industry liveweight targets that are set to ensure heifers achieve good reproductive performance and milk production. The aim of this study was to determine if more dairy heifers born between the 2011-12 and 2014-15 dairy seasons (current) in New Zealand are achieving liveweight targets since a study on heifers born between the 2006-07 and 2010-11 dairy seasons (historic). In all age groups the mean live weight of current heifers was heavier than that of historic heifers. There were also a greater percentage of the current heifers at or above their target live weight compared with the historic heifers (P<0.001), suggesting that the rearing of dairy heifers has improved. The greatest improvement was seen at 15 months of age (mating) when 25\% of historic heifers were at or above target compared with 56\% of current heifers. Despite the improvement, 44\% of current heifers were below target at mating and 65\% were below target pre-calving (22 months of age). At 22 months of age, current heifers were on average nearly 42 kg below target live weight. By failing to achieve targets near calving, farmers are not capturing potential milk production benefits.}, issn = {1176-5283}, author = {Handcock RC and Lopdell TJ and McNaughton LR} } @conference {3672, title = {Performance and intake of high-yielding Holstein cows offered a TMR either alone or with access to grazing for six hours per day}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {76}, year = {2016}, month = {07/2016}, pages = {90-93}, address = {Adelaide}, abstract = {Grazing of lactating cows is a decreasing practice in Europe despite numerous potential benefits. In parts of Europe, farmers are required to graze all dairy cows for at least six hours per day during summer, but little is known about the effect on the performance of high-yielding animals. A study was undertaken to investigate the effects of the following treatments on high-yielding Holstein cow performance: continuous housing (C; control) with a total mixed ration (TMR), a six-hour grazing period directly after morning milking with TMR offered ad libitum when housed (EG; early grazing), a six-hour grazing period following morning milking with 75\% of ad-libitum TMR when housed (RT; restricted TMR), or TMR access for one hour following morning milking, followed by a six-hour grazing period (DG; delayed grazing) then housed with TMR offered ad libitum. Total dry matter intake (DMI) was similar in C, EG and DG but lower in RT (26.9, 26.0, 26.7 and 23.8 kg DM/cow/d; P <0.001; SED 0.524). Milk yield was also lowest in RT, with mean values of 45.7, 44.2, 44.9 and 41.7 kg/cow/d in C, EG, DG and RT respectively (P =0.001; SED 0.993). High-yielding cows can be grazed for a six-hour period during the day with little impact on milk production provided TMR is unrestricted when housed.}, issn = {1176-5283}, author = {Atkins NE and Cianchi C and Rutter SM and Williams SJ and Gauld C and Charlton GL and Sinclair LA} } @conference {3672, title = {Performance recording of NZ Corriedales}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {76}, year = {2016}, month = {07/2016}, pages = {46-48}, address = {Adelaide}, abstract = {Personal photo archives (W.R.E Booker) dated from 1926, showed early Corriedale ewe lambs were phenotypically similar to a cross between Ryeland and Southdown sheep. Since then both phenotypic and productive traits have been dramatically improved. This paper will review the history of the breed improvement in NZ Corriedales from the perspective of a sheep breeder. Prior to 1970 very little performance recording took place in the Corriedale breed. There was however a huge importance placed on phenotype with show ribbons and certificates being highly sought after not only for prestige among the breeder society but as they usually led to sales of rams to commercial breeders.}, issn = {1176-5283}, author = {Booker J} } @conference {3672, title = {Preliminary investigations into the trait of residual energy intake in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {76}, year = {2016}, month = {07/2016}, pages = {34-37}, address = {Adelaide}, abstract = {Residual energy intake (REI), also referred to as residual feed intake, is one way of describing feed efficiency, and is an estimate of whether or not an animal is eating more or less than expected for its weight and growth rate. The REI trait has been investigated in a number of production-animal species, but only pilot study data exists for New Zealand sheep. This paper investigates phenotypic variability in the trait of REI for a cohort of 197 growing ewe lambs. The animals were approximately nine months old at the commencement of the trial. Their daily intake of a lucerne pellet-diet was measured for 56 days using an automated feeder that recorded weight of feed consumed in real time. The animals were weighed twice weekly. The standard REI model involves fitting metabolic mid-test live weight and live weight gain to predict energy intake. Both measurements fitted were significant (P<0.001), with an overall R2 for the model of 0.78. Grouping of the animals in to Low-, Mid- and High-efficiency groups revealed a 24\% difference in energy intake between the low and high groups which is consistent with studies in other species. The comparison of attributes of the efficiency groups did reveal differences in fatness with the high-efficiency animals fatter at the start of the data collection, but they did not lay down as much fat during the trial as the low-efficiency group. Given the phenotypic variability is consistent with that observed in other production-animal species, additional cohorts will be measured in the coming years to generate a data set to investigate the genetics of the trait, and further investigate the role of fat within the REI model.}, issn = {1176-5283}, author = {PL Johnson and Miller SP and Knowler K} } @conference {3672, title = {Relationship between social dominance and milk production of dairy cows grazing pasture}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {76}, year = {2016}, month = {07/2016}, pages = {69-72}, address = {Adelaide}, abstract = {The objectives of this experiment were to study factors determining social dominance of grazing dairy cows and the relationship between social dominance and milk production under grazing systems. A total of 252 spring calving Friesian x Jersey dairy cows in three groups differing in stocking rate and herd size grazing perennial ryegrass and white clover pasture were observed for three months in early lactation to determine their dominance value. All cows ranged in age from 2 to 11 years and live weight (LW) ranged from 340 kg to 648 kg. Dominance values were determined by social interactions indicating dominance and submission between cows. Social interactions were recorded on a win and loss basis. In all three groups, the dominance value was positively correlated (P<0.05) with age (r = 0.42 to 0.65), live weight (r = 0.33 to 0.47) and milk production (r = 0.32 to 0.42), but no relationship with body condition score was found. In conclusion, older cows with higher live weight were more dominant and tended to have higher milk production.}, issn = {1176-5283}, author = {Hussein AN and Al-marashdeh O and Bryant RH and Edwards GR} } @conference {3672, title = {Reproductive performance of singleton and twin female offspring born to ewe-lamb dams and mature adult dams}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {76}, year = {2016}, month = {07/2016}, pages = {151-154}, address = {Adelaide}, abstract = {This study was undertaken to compare the reproductive and live weight performance of female singleton and twin ewes born to either mature or young dams from 18 months to 2.5 years of age. One hundred and fifteen singleton- and twin-born female offspring born to either ewe-lamb (8 months at breeding) or adult ewe dams were maintained as one cohort under commercial New Zealand grazing conditions. Ewe live weights and body condition scores were recorded, as were ovulation rates at a synchronised breeding and number of fetuses present at pregnancy scanning. The live weight of ewes born to ewe-lambs were lighter (P<0.05) than those born to adult ewes at breeding and during their first pregnancy but not (P>0.05) at the weaning of their lambs. Twin-born ewes were lighter (P<0.05) than their singleton-born counterparts. There was no difference in corpora lutea number (P>0.05) at breeding or number of fetuses at pregnancy scanning. Lambs whose grand dam was a ewe-lamb were heavier at birth (P<0.05) but not at weaning (P>0.05) compared to those lambs whose grand dams was an adult ewe. This data suggests there are few negative impacts from selecting progeny born to ewe lambs as replacement ewes. However, before this hypothesis can be supported, lifetime data of these ewes needs to be collected.}, issn = {1176-5283}, author = {Loureiro MFP and Pain SJ and Kenyon PR and Blair HT} } @conference {3672, title = {Reproductive production constraints within the New Zealand racing industry}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {76}, year = {2016}, month = {07/2016}, pages = {146-150}, address = {Adelaide}, abstract = {The New Zealand Thoroughbred industry has seen rationalisation in response to changes in the domestic market and more recently the Global Financial Crisis (GFC). To quantify changes in production, end-of-season reproductive data for active Thoroughbred sires were extracted for the 1989/90 to 2011/12 breeding seasons. There were reductions in the numbers of mares bred and foals produced (10,176 mares \& 5,882 foals vs. 5,826 mares \& 3,927 foals, respectively in 1989/90 and 2011/12 seasons) resulting in a greater relative proportion of foals registrations (57\% vs. 67\%). During this period, the number of active sires decreased (265 vs. 94) and number of mares per sire increased (33 IQR 18-53 vs. 49 29-91). The 2007/08 season (GFC) was associated with an acute reduction in the number of shuttle stallions imported for breeding (from 23\% in 2006/07 to 11\% of active sires in 2007/08), and a temporary increase in number of mares bred (13\%), in response to the 2007 Equine Influenza outbreak in Australia. The proportion of sires covering >100 mares per season increased from 6\% (1989/90) to 25\% (2011/12). Despite the reduction in active broodmares during the same period (43\%), there has not been a proportional decrease in export numbers (24\%) or domestic numbers of horses racing (6.5\%).}, issn = {1176-5283}, author = {Rogers CW and Gee EK and Bolwell CF} } @conference {3672, title = {Supply curves for yields of dairy products from first-lactation Holstein Friesian, Jersey and Holstein Friesian-Jersey crossbred cows accounting for seasonality of milk composition and production.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {76}, year = {2016}, month = {07/2016}, pages = {139-143}, address = {Adelaide}, abstract = {The economic efficiency of a milk-processing system is influenced by seasonality of the milk supply, and changes to milk composition, influences the product potential of that milk. Lactation curves for milk yield and composition for seasonal calving first-lactation Holstein Friesian (F), Jersey (J) and Holstein Friesian-Jersey crossbred (FxJ) cows were used as inputs in a deterministic simulation model to produce seasonal curves for daily yields of dairy products. The dairy products were whole milk powder, skim milk powder, cheese, or butter. Dairy product potential was estimated for each animal from a population of 4333 mixed-breed, first-lactation cows. Lactation lengths differed (P<0.0001), among F, FxJ, and J, which averaged 219, 222 and 221 days respectively. Total-lactation milk yield was different (P<0.0001) among breeds and averaged 3257, 3092 and 2902 litres for F, FxJ and J cows, respectively. Whole-milk powder potential (yield per 1000 L of milk) was greatest at the start of the season and least at the end of the season, whereas cheese-production potential (yield per 1000 L of milk) followed the opposite pattern. Total-lactation whole-milk powder yield was different among breeds (P<0.0001) at 366, 338 and 312 kg of whole-milk powder for F, FxJ and J cows, respectively. Total-lactation cheese yield was also different among breeds (P<0.0001), and was 371, 375 and 361 kg for F, FxJ and J cows, respectively. The supply curves indicate that milk is best processed into whole or skim milk powder during peak season, and cheese and butter at the end of lactation. However, seasonal production of specific products would limit the use of by-product lactose from cheese manufacture in the production of milk powders, and thus negate the efficiency gains from changes to processing priorities.}, issn = {1176-5283}, author = {Sneddon NW and Lopez-Villalobos N and Davis SR and Hickson RE and Shalloo L and Garrick DJ} } @conference {3672, title = {Sustained diuretic effect of plantain when ingested by sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {76}, year = {2016}, month = {07/2016}, pages = {14-17}, address = {Adelaide}, abstract = {Narrow-leaved plantain (Plantago lanceolata L.) was investigated for its potential to act as a diuretic in sheep. For seven days, two groups of sheep (n = 8) were provided with either ryegrass or plantain diets that had similar water content. Dry matter in feed, fresh faecal weight, and faecal water content was measured daily, as well as volume, specific gravity and osmolality of urine. Urine volumes on Day 1 of the trial were significantly different to those of Days 2-6 of the trial (P < 0.05) so the results were analysed separately. Plantain sheep had a higher volume of urine (by 1.7 L, P < 0.05) on Day 1 than Ryegrass sheep and continued to produce about 0.5 L more urine each day than Ryegrass sheep for the remainder of the study period. Because intakes of feed and feed water content for the two diets were essentially equal, this study provides the first direct evidence to show that plantain causes a diuresis when it is ingested by sheep, possibly by reducing reabsorption of water in the kidneys.}, issn = {1176-5283}, author = {O{\textquoteright}Connell CA and Judson HG and Barrell GK} } @conference {3672, title = {Urine volume of non-lactating dairy cows in late gestation fed forage based diets in winter}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {76}, year = {2016}, month = {07/2016}, pages = {22-25}, address = {Adelaide}, abstract = {Quantitative information on urine volume of dairy cows fed winter forages is required to accurately evaluate nitrate leaching risks on these diets. Thirty-two Friesian x Jersey non-lactating, pregnant dairy cows were fed either 10 kg DM of fodder beet with 5.6 kg DM of ryegrass baleage or 16.4 kg DM of kale with 6.4 kg of oat silage. Cows were fitted with a urine meter for 24 to 72 hours to record the frequency and volume of urine events. Daily urine volume (28 {\textpm} 3 L/cow/day), frequency (9 {\textpm} 0.89 events/cow/day), and event volume (3.2 {\textpm} 0.3 L/event) were not significantly different between fodder beet and kale treatments. This was despite respective differences in total apparent water (51 vs. 70 L/cow/day, {\textpm} 2, P<0.001) and nitrogen (N) intake (231 vs. 488 g N/cow/ day, {\textpm} 9.4, P<0.001). In this study, water consumption and N intake did not appear to be linked with urine volume of dairy cows when two different forage diets were compared.}, issn = {1176-5283}, author = {Farrell LJ and Bryant RH and Hague H and Edwards GR} } @conference {3672, title = {Using genomic information to predict sex in dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {76}, year = {2016}, month = {07/2016}, pages = {26-30}, address = {Adelaide}, abstract = {Sex misassignment of animals in breeding programmes can arise from sources such as misidentification and data-entry errors. The objective of this study was to develop a test for checking sex using Single Nucleotide Polymorphism (SNP) chip genotypes on chromosome X. All animals in this study were genotyped using the GeneSeek Genomic Profiler LD v3 (GGPv3) SNP chip. After filtering, 16478 sex-verified animals (15703 cows and 775 bulls) were available in the training set. The proportion of heterozygous SNPs on chromosome X was used to predict sex. The distribution of heterozygosity was bimodal in the training population with a clear gap between 0.01 and 0.03. Using the heterozygosity cutoff of 0.02 resulted in 100\% and 99.6\% prediction accuracy for males and females, respectively. Additional analysis determined that four incorrectly classified females were either XO or inbred. The test was validated on an independent set of 2212 animals, which resulted in seven animals for which the predicted sex differed to the recorded sex. Physical examination of these animals revealed that the predicted sex was correct in all cases. The method developed is a useful addition to quality control of genotypes obtained as part of a genomic selection programme.}, issn = {1176-5283}, author = {Zhang IL and Couldrey C and Sherlock RG} } @conference {3672, title = {Variation in total body adipose and adipose partitioning in maternal sheep estimated using computed tomography scanning}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {76}, year = {2016}, month = {07/2016}, pages = {122-125}, address = {Adelaide}, abstract = {In sheep, decreasing adipose or fat is desirable in prime lambs; however, adipose also has a role in the productive capacity of the maternal ewe. There are three main depots of adipose within the body of a live animal: sub-cutaneous, intermuscular and internal (or visceral). To understand if differences exist between animals in adipose deposition and partitioning, a study was undertaken using 37 New Zealand composite-breed maternal ewes, scanned using computed tomography on three occasions from nine through to 17 months of age. The images produced were processed to estimate the weight of subcutaneous, intermuscular and visceral adipose (along with lean and bone), with the weights then expressed as a percentage of total adipose to investigate partitioning. The raw average total body adipose remained proportionate across the three scans at approximately 32\% of total empty body weight. The resulting data were analysed using a REML variance components analysis in Genstat. The repeatability of fat distribution across the three scans was high, ranging from 0.77 for proportion of intermuscular adipose through to 0.83 for proportion of subcutaneous adipose. The component Animal was significant for all traits indicating between animal variation in partitioning of adipose between the depots within individual animals. Cumulatively, these results demonstrate that there is variability in adipose deposition and partitioning in New Zealand sheep. If under genetic control, variability that could be exploited to optimise adipose to best meet the requirements of prime lamb production and maternal ewes.}, issn = {1176-5283}, author = {PL Johnson and Bain WE and Johnstone P and Bixley M and Knowler K} } @conference {3672, title = {2015 NZSAP Living Legend Address {\textendash} Invermay Agricultural Centre}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {149}, address = {Dunedin}, abstract = {Some of the best science is done by those who are excited by their research and by working with industry. Many breakthroughs come from people noticing, and following up on, unusual observations or anomalies. Often, their passions are funded {\textquotedblleft}from the back pocket{\textquotedblright} for several years; until sufficient information is secured to justify a formal funding application. The Living Legend Lecture invites distinguished longterm members of NZSAP to make a scholarly presentation at the Society{\textquoteright}s annual conference in recognition of their contribution to New Zealand Animal Production over a substantial period of time. Heeding the Guidelines recommendation to consider members resident in the area holding the conference, the 2015 organising committee chose to nominate the contributions of the scientists and technical staff of an iconic Institution, rather than acknowledge a single individual{\textquoteright}s work. No specific animal production {\textquotedblleft}theme{\textquotedblright} was selected. Instead, it was decided to highlight the contribution of the Invermay Agricultural Centre as a whole...}, issn = {1176-5283}, author = {Shackell GH and Drew KR and Fennessy PF and Allison AJ and McEwan JC and Crawford AM} } @conference {3672, title = {Abstracts from the Ewe milk products and sheep dairy conference 2015}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {278-282}, address = {Dunedin}, abstract = { }, issn = {1176-5283}, author = {Anonymous} } @conference {3672, title = {Analysing hidden patterns of farmers{\textquoteright} preferences for farm performance characteristics that may be related to tail-docking practice decisions}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {205-209}, address = {Dunedin}, abstract = { We investigated how multivariate statistics can be used to determine the different patterns of preferences that may exist within a farmer population. As a case study, we used adaptive conjoint analysis to analyse farmers{\textquoteright} preferences for nine farm performance characteristics that may be related to tail docking practice decisions. As expected, at the whole population level, farmers{\textquoteright} preferences for these traits were found to be highly heterogeneous, with only the most important issues and least important issues being able to be statistically differentiated. Using Cluster Analysis and Principal Components Analysis we found some hidden relationships and identified the existence of four groups of farmers that had greater preferences for different characteristics; group one preferred having less dags and less costs associated with dagging and crutching, group two preferred to reduce euthanasia from uterine prolapse and rectal prolapse, group three preferred to avoid stressing lambs at the time of docking and group four preferred to have less fly-strike and greater weaning weights. We discuss how the use of multivariate statistics allowed a deeper interpretation of preference studies in a context of importance to NZ farmers.}, issn = {1176-5283}, author = {Martin-Collado D and Byrne TK and Amer PR and Behrent MJ and Maclennan G and Kerslake JI} } @conference {3672, title = {Beef cattle wintering systems: effects on cattle and pasture.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {167-171}, address = {Dunedin}, abstract = { The wet winter months are a risk period for damage to pasture under grazing systems in New Zealand. The use of stand-off pads and alternative forages and grazing systems may alleviate these risks, but may also impact on the performance and welfare of cattle. This experiment compared four wintering systems for growing beef calves (9{\textendash}11 months old, n=103) in terms of growth rate and welfare of calves, and damage to pasture. Treatments were a forage crop of oats, set-stocked grazing on pasture, breakfed on pasture, and break-fed on pasture with use of a concrete feedpad and wood-shavings stand-off area when the soil was wet. Liveweight gain was greatest (P<0.05) for the set-stocked (0.81{\textpm}0.02 kg/day) and break-fed calves (0.52{\textpm}0.02 kg/day), and least for the calves in the feedpad (0.19{\textpm}0.02 kg/day) and crop treatments (0.10{\textpm}0.02 kg/day). The percentage of calves lying down was least in the break-fed and oats treatments (P<0.05) but faecal corticosterone concentration was greatest in the feedpad treatment (P<0.05). Pasture damage was greater under rotational grazing (score 3.8/5) than set stocking (score 2.9/5), but use of the feedpad did not prevent damage to pasture (score 3.4/5). Set-stocking had the best outcomes for calves and pasture.}, issn = {1176-5283}, author = {Little CL and Hickson RE and Martin NP and Beausoleil NJ and Cockrem JF and Kenyon PR and Horne D and Morris ST} } @conference {3672, title = {Blank panels in sheep yards encourage sheep to jump}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {191-194}, address = {Dunedin}, abstract = { The lateral sides of two adjacent forcing pens and the sides of the races were clad with plywood to improve sheep flow in yards at AgResearch Lincoln farm. Following this, two flocks of yearling sheep were run through the yards every two weeks for drafting. One flock was exclusively male (n = 223), while the other was all female (n = 248). On the first occasion, a number of yearlings jumped out of the forcing pen. This had not been observed in previous years, so the number jumping was recorded. A non-parametric time-to-event analysis method, the Kaplan-Meier estimator, was used to obtain cumulative incidence functions of sheep jumping. If they were to jump out of the pen, the sheep had two choices, a pipe rail fence (or gate) or a blank plywood wall. During 14 handling events, 1\% of yearlings jumped the pipe rails whereas 7\% jumped the plywood wall (P < 0.001). These yearlings chose to jump a fence they could not see through. Clearly there are many variables that could be tested in this model.}, issn = {1176-5283}, author = {Scobie DR and O{\textquoteright}Connell D and van Koten C and R Phiskie} } @conference {3672, title = {Body condition and morphometric measures of adiposity in a cohort of Pony Club horses and ponies in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {195-199}, address = {Dunedin}, abstract = { A cross-sectional study was conducted to describe and compare the body condition and morphometrics of Pony Club (PC) horses and ponies at two points in the year. Data were collected from a cohort of PC riders in spring (n=158) and autumn (n=155), with 73 repeat measurements across the two seasons. There were more ponies (68\%, 164/240, wither-height <=148 cm) than horses in the study population. Most (76\%, 183/240) animals were kept on ad libitum pasture throughout the year and were fed small quantities of supplementary feed. The median body condition score (BCS) of the animals was 6 (interquartile range 5-7). Forty-seven per cent (112/240) of the animals were scored {\textquoteleft}fat{\textquoteright} (BCS >=7) and 25\% (61/240) presented with a cresty-neck score >=3. There was poor inter-rater agreement between the study personnel and owners for BCS of horses (Kappa=0.26) and ponies (Kappa=0.11). The study personnel identified 54\% (88/162) of ponies as {\textquoteleft}fat{\textquoteright}, whereas owners underestimated the BCS of ponies, and identified only 40\% (65/162) as {\textquoteleft}fat{\textquoteright} (P<0.001). The measurements of body weight did not differ between seasons, and only some morphologybased assessments of adiposity differed between seasons. Overall, 17\% (15/88) of {\textquoteleft}fat{\textquoteright} ponies and 21\% (11/53) of those with {\textquoteleft}cresty-necks{\textquoteright} were reported to have had a previous history of laminitis. Laminar rings were observed in 98\% (234/240) of the PC horses and ponies. The study highlighted that horses and ponies kept on pasture maintain body weight and condition from spring to autumn, but this finding may be biased by the high percentage of {\textquoteleft}fat{\textquoteright} ponies in the study population. The poor inter-rater agreement for BCS, particularly with ponies, and similar morphological measurements between seasons, highlights the challenges with using these measurements of adiposity in ponies}, issn = {1176-5283}, author = {Fernandes KA and Rogers CW and Gee EK and Bolwell CF and Thomas DG} } @conference {3672, title = {BRIEF COMMUNICATION: Birth weight of calves born to dairy cows in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {257-259}, address = {Dunedin}, abstract = { }, issn = {1176-5283}, author = {Hickson RE and Zhang IL and McNaughton LR} } @conference {3672, title = {BRIEF COMMUNICATION: Chitosan is a highly effective in vitro antibacterial agent against the strains of bacteria causing footrot, but is not effective in treating stage-four footrot on farm.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {172-174}, address = {Dunedin}, abstract = { }, issn = {1176-5283}, author = {Bekhit AEA and Mros S and Ali MA and McConnell M} } @conference {3672, title = {BRIEF COMMUNICATION: Composition of milk sampled from beef-cross-dairy cows unaccustomed to milking.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {260-262}, address = {Dunedin}, abstract = { }, issn = {1176-5283}, author = {Hickson RE and Back PJ and Coleman LW and Lopez-Villalobos N and Kenyon PR and Morris ST} } @conference {3672, title = {BRIEF COMMUNICATION: Developing genomic tools in the New Zealand Deer Industry}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {91-93}, address = {Dunedin}, abstract = { }, issn = {1176-5283}, author = {Rowe SJ and Clarke SM and Van Stijn TC and Hyndman DL and Ward JF and McEwan KM and Dodds KG and McEwan JC and Newman S-AN and Asher GW} } @conference {3672, title = {BRIEF COMMUNICATION: Do high-milk diets affect the growth rate of heifers prior to weaning?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {263-265}, address = {Dunedin}, abstract = { }, issn = {1176-5283}, author = {Cardoso DS and Hickson RE and Laven RA and Coleman LW and Back PJ} } @conference {3672, title = {BRIEF COMMUNICATION: Genetic control of the rumen microbiome in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {67-69}, address = {Dunedin}, abstract = { }, issn = {1176-5283}, author = {Rowe SJ and Kittelmann S and Pinares-Pati{\~n}o CS and Wood GR and Dodds KG and Kirk MR and Ganesh S and Hickey SM and Janssen PH and McEwan JC} } @conference {3672, title = {BRIEF COMMUNICATION: Genetic parameters for growth, carcass and meat quality traits in New Zealand sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {94-96}, address = {Dunedin}, abstract = { }, issn = {1176-5283}, author = {Brito LF and Miller SP and Clarke SM and Dodds KG and Bain WE and Lee MA and Pickering NK and McEwan JC} } @conference {3672, title = {BRIEF COMMUNICATION: Genetic parameters for meat traits assessed in the Headwaters New Zealand Progeny Test}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {111-113}, address = {Dunedin}, abstract = { }, issn = {1176-5283}, author = {PL Johnson and Charteris A and Tate ML and Dodds KG} } @conference {3672, title = {BRIEF COMMUNICATION: Intake of ewe lambs is influenced by the dry matter percentage of the feed consumed}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, address = {Dunedin}, issn = {1176-5283}, author = {PL Johnson and Miller SP and Knowler K and Bryson B and Dodds KG} } @conference {3672, title = {BRIEF COMMUNICATION: Metabolite profiling in New Zealand milk}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {39-41}, address = {Dunedin}, abstract = { }, issn = {1176-5283}, author = {Davis SR and Jaine J and Obolonkin V and Braggins TJ and Cooney TP and Scott A and Spelman RJ} } @conference {3672, title = {BRIEF COMMUNICATION: Modelling liveweight change to inform residual feed intake models in growing lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {225-227}, address = {Dunedin}, abstract = { }, issn = {1176-5283}, author = {PL Johnson and Miller SP and Knowler K and Bryson B and Dodds KG} } @conference {3672, title = {BRIEF COMMUNICATION: Onset of breeding season in Dorset Horn ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, address = {Dunedin}, abstract = { }, issn = {1176-5283}, author = {PL Johnson} } @conference {3672, title = {BRIEF COMMUNICATION: Optimizing a fasting protocol to assess live weight of sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {223-224}, address = {Dunedin}, abstract = { }, issn = {1176-5283}, author = {Wilson RF and Hardwick-Smith JA and Logan CM and Corner-Thomas RA and Bywater AC and Greer AW} } @conference {3672, title = {BRIEF COMMUNICATION: Substitution of perennial ryegrass with forage rape reduces methane emissions from sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {64-66}, address = {Dunedin}, abstract = { }, issn = {1176-5283}, author = {Sun XZ and Sandoval E and Pacheco D} } @conference {3672, title = {BRIEF COMMUNICATION: Walking distance and energy expenditure of beef cows grazing on hill country in winter}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {164-166}, address = {Dunedin}, abstract = { }, issn = {1176-5283}, author = {Martin NP and Hickson RE and Draganova I and Horne D and Kenyon PR and Morris ST} } @conference {3672, title = {Colostral immunoglobulin G as a predictor for serum immunoglobulin G concentration in dairy calves}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {3-8}, address = {Dunedin}, abstract = { Feeding newborn calves high-quality colostrum is of well-recognised importance as calves that do not receive an adequate concentration of immunoglobulin-G (IgG) have an increased risk of morbidity and mortality. This experiment aimed to characterise IgG concentrations in colostrum from the first milking in New Zealand dairy cows, examine IgG status of calves, and to evaluate the use of a refractometer for estimating quality of colostrum in terms of IgG concentration. Heifer calves entered the calf shed at 0-24 hours of age and were fed pooled first-milking colostrum within eight hours of entering the shed. Blood samples were taken the following morning. Cows were individually milked and samples from individual and pooled colostrum were analysed. IgG concentration of serum and colostrum samples were determined by turbidimetric immunoassay. IgG concentration was adequate according to commercial reference ranges in 70.1\% of individual colostrum, 80.0\% of pooled colostrum and 82.5\% of calf serum samples. There was no relationship between calf serum and IgG concentration in dam or pooled colostrum. The refractometer was a good predictor of IgG concentration in serum (r=0.64, P<0.0001) and colostrum both in dam (r=0.87, P<0.0001) and pooled (r=0.81, P<0.0001) samples. The relationship between IgG concentration and refractometer reading indicates that it could be a useful on-farm tool.}, issn = {1176-5283}, author = {Coleman LW and Hickson RE and Amoore J and Laven RA and Back PJ} } @conference {3672, title = {A comparison of microbial protein synthesis in beef steers fed ad libitum winter ryegrass or fodder beet}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {251-256}, address = {Dunedin}, abstract = { Microbial protein synthesis of steers (liveweight 286{\textpm}9 kg) was compared with diets of ad libitum winter grass and fodder beet with 1 kg DM of lucerne silage. The experimental design was a four-by-two treatment comparison (experiment 1 and 2), using 11 day individual pen trials with total faecal and urinary collection. The trials assessed in vivo digestibility of diets, and diurnal variations in rumen parameters (pH volatile fatty acid, ammonia and urea concentrations) and urine and faeces production and N excretion. Microbial protein production was estimated from purine derivatives determined from total urine collection. Dry matter digestibility, voluntary dry matter intake and microbial protein supply to the steers, and the mean diurnal rumen pH, were higher in the steers fed the fodder-beet treatment than in those fed the winter-grass treatment. Fodder beet supplied almost twice as much microbial protein as winter grass despite a lower crude protein concentration of the diet. Total rumen VFA and ammonia concentrations were lower for the fodder-beet treatment than for winter grass but the rumen urea concentration was higher in the fodder-beet treatment. The observed high microbial protein supply with the fodder beet diets is likely the result of ruminal and extra-ruminal adaptations to greater nitrogen recycling in low dry matter diets of high energy density and low crude protein concentrations.}, issn = {1176-5283}, author = {Prendergast SL and Gibbs SJ} } @conference {3672, title = {Contract session: Application of genetic technologies to the New Zealand sheep industry}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {184-187}, address = {Dunedin}, abstract = { }, issn = {1176-5283}, author = {Jopson NB and Linscott EM and Young MJ and Dodds KG and Clarke SM and Rowe SJ and Byrne TJ and Alder GF} } @conference {3672, title = {The difficulties in reviewing ergovaline}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {179-183}, address = {Dunedin}, abstract = { The endophytic alkaloid, ergovaline, is a secondary metabolite of a number of endophytes associated with perennial ryegrass. Ergovaline is known to protect ryegrass against attack by a range of insect pests, but can also negatively affect domestic ruminants. We have recently reviewed the physiological responses and metabolism of ergovaline and the effect of its consumption on animal production. The main focus of this paper is on the difficulties encountered in preparing these reviews. These include the lack of a cost-effective source of ergovaline to allow for robust dose-dependent trials resulting in ergovaline treatments based on seed sources presented in a range of processed forms, or as ryegrass pasture in which ergovaline is often associated with other alkaloids. Intake of ergovaline is often difficult to predict because ergovaline concentration of the diet on offer may not represent the concentration in the diet consumed. Furthermore, the mean live weight and level of production of the experimental animals is not always available to allow a prediction of ergovaline intake. Any change in gut-fill in response to ergovaline consumption needs to be accounted for when assessing any impact on body weight. Experimental objectives need to be clear, as the effects of short-term ergovaline exposure can be masked in a production system by subsequent compensatory growth/production. By identifying these difficulties, we hope that future work on ergovaline may be more consistent and of greater value to further reviews.}, issn = {1176-5283}, author = {Nicol AM and Klotz JL} } @conference {3672, title = {Diurnal pattern of rumen environment and rumen fill in lactating grazing dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {136-139}, address = {Dunedin}, issn = {1176-5283}, author = {Saldias B and Gibbs SJ} } @conference {3672, title = {The effect of dam age on ewe offspring productive performance and efficiency}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {239-242}, address = {Dunedin}, abstract = { productive performance and efficiency of singleton ewe offspring to four years of age. Live weight was recorded every two months from birth to four years of age for singleton ewe progeny born to either ewe-lamb dams or adult ewes (ewe-lamb progeny: ELP, n = 20; adult-ewe progeny: AEP, n = 25). The number of lambs born and weaned, and weight (kg) of lamb born and weaned were determined for each ewe for each productive year and as a combined total. Ewe production efficiency was calculated for each year and as a combined total. Results show that AEP were heavier at birth and remained heavier until one year of age (P<0.05). Live weight was again greater (P<0.05) for AEP in mid-pregnancy in 2010 and at weaning in 2011. The number of lambs born and weaned and the weight of lamb born and weaned per ewe did not differ in any of the three productive years or for the combined total. Ewe production efficiency was not affected by dam age, with similar efficiencies reported for ELP and AEP. The results from this study show that despite experiencing a weight penalty, the productive performance and efficiency of singleton ewe progeny born to ewe-lamb dams, if conventionally bred themselves as 18 months of age, appears to be similar to that of singleton ewe progeny born to mature adult ewes.}, issn = {1176-5283}, author = {Pain SJ and Loureiro MFP and Kenyon PR and Blair HT} } @conference {3672, title = {Effect of dam age on the growth and body composition of singleton ram offspring to 11 months of age}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {231-234}, address = {Dunedin}, abstract = { Studies in sheep suggest that ewe-lamb dams produce smaller offspring compared to mature adult ewes. This study was designed to examine the growth trajectory, body composition and carcass characteristics of 48 singleton Romney male progeny born to either ewe-lambs (ELP; n = 17) or adult ewes (AEP; n = 21). Both dam groups were maintained together under commercial grazing conditions during breeding, pregnancy and lactation. After, weaning the ram lambs continued to be managed together under commercial conditions. Ram offspring were weighed and measured at birth. They were subsequently weighed every two months until 11 months of age (d322). At d322, nine ELP and 10 AEP were euthanised and several body-size and composition measurements were taken. The ELP were lighter and smaller (P<0.05) at birth compared with AEP and they remained significantly (P<0.05) lighter until d218. After d218 this difference in live weight became a tendency (P<0.1). Slaughter data revealed that ELP tended (P<0.1) to have more visceral fat than AEP (P<0.05). Similarly, dual-energy X-ray absorptiometry (DXA) was performed on the left hind-leg and showed that AEP tended to have greater (P<0.1) lean mass compared with ELP. Despite the liveweight differences and the tendency towards differences in adiposity observed at slaughter, ram lamb carcass weight and dressing-out percentage were unaffected indicating that ram offspring meat production from ewe-lamb dams is similar to that from mature adult ewes.}, issn = {1176-5283}, author = {Loureiro MFP and Pain SJ and Kenyon PR and Firth EC and Rogers CW and Blair HT} } @conference {3672, title = {The effect of ewe nutrition and body condition score during very late pregnancy and the perinatal period on the behaviour of twin-bearing ewes and their lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {219-222}, address = {Dunedin}, abstract = { Nutrition of ewes during pregnancy may affect the behaviour and survival of lambs. In this experiment, ewes were allocated {\textquoteleft}low{\textquoteright} (pasture mass 800-1000 kg DM/ha), {\textquoteleft}medium{\textquoteright} (pasture mass 1200-1400 kg DM/ha) or {\textquoteleft}high{\textquoteright} nutrition (pasture mass 1500-1700 kg DM/ha) from day 141 of pregnancy until weaning. All treatments included ewes of body condition score (BCS) 2.0, 2.5 or 3.0 as measured on day 98 of pregnancy to give a 3x3 factorial design. Behaviours of ewes and lambs were recorded in the paddock at tagging 3-18 hours after birth. Lambs born to ewes on the high treatment were quicker to stand than those on the low treatment (median time 15.5 versus 53.5 seconds; P<0.05), but neither group differed from lambs on the medium treatment (16.5 seconds; P>0.05). There were no differences among treatments or BCS groups in time taken for the lamb to make contact with dam, suck from dam or follow their dam. Maternal behaviour score of the ewes was not affected by BCS or treatment. The percentage of lambs that bleated was similar for lambs from all BCS groups and treatments. BCS and nutrition of ewes in late pregnancy and during the neonatal period had little influence on the behaviour of ewes and lambs.}, issn = {1176-5283}, author = {Gronqvist GV and Hickson RE and Corner-Thomas RA and Kenyon PR and Stafford KJ and Morris ST} } @conference {3672, title = {The effect of grazing high-sugar ryegrass on lamb performance}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {235-238}, address = {Dunedin}, abstract = { A multi-year grazing study was undertaken on three commercial properties in the southern South Island to compare the performance of lambs grazing high-sugar ryegrass/white clover (HSG) with lambs grazing a standard ryegrass/white clover pasture (SRG). Cultivars were established in late spring 2012; approximately 400 lambs in each treatment group per property grazed the swards in autumn 2013 and summer/autumn 2014 at a density of 30 to 35 lambs per hectare. Lambs were weighed regularly throughout the season; those that reached the desired weight were sent for slaughter. Across both years and properties, lambs grazing the HSG pasture grew 31 grams per day faster (17\%) on average than those grazing SRG (P<0.001). These lambs were an average of 0.4 kg heavier in terms of carcase weight at slaughter (P<0.001) yielding 0.2 kg more meat per carcase based on VIAScan yield. These results suggest that lambs grazing HSG outperform those grazing SRG.}, issn = {1176-5283}, author = {Proctor LE and Craig HJB and McLean NJ and Fennessy PF and Kerslake JI and Behrent MJ and Chuah JCL and Campbell AW} } @conference {3672, title = {Effect of shearing on lamb growth and carcase performance}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {215-218}, address = {Dunedin}, abstract = { A study was undertaken on three properties throughout New Zealand to determine the impact of shearing on lamb performance and whether this offered any economic benefit to farmers as a farm-management tool. A total of 1,183 lambs were randomly allocated to one of four treatments, shorn fasted, bellied fasted, woolly fasted and woolly not fasted. Shorn fasted lambs grew 12 g/d faster than woolly fasted lambs (P<0.05), but at similar rates to bellied lambs and woolly not fasted lambs. There were no differences among treatments for carcase weight, meat yield or proportion of lambs killed at slaughter. The difference observed in average daily gain between the shorn fasted and the woolly fasted lambs, and the lack of difference observed between shorn fasted and woolly not fasted lambs, indicated that while shearing improved lamb growth rates, the weight loss due to fasting overnight was not overcome by the increased growth rate associated with shearing. While there was no economic benefit associated with lamb carcase weight or time to slaughter, at a wool price of $5.40 per kg clean, shorn lambs were still of a greater value to farmers compared to lambs from all other treatments.}, issn = {1176-5283}, author = {McLean NJ and Craig HJB and Fennessy PF and Behrent MJ and Kerslake JI and Campbell AW} } @conference {3672, title = {The effects of feeding maize silage at different times prior to a herbage meal on dry matter intake, milksolids production and nitrogen excretion in late-lactation dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {140-144}, address = {Dunedin}, abstract = { The objective of this study was to determine the effect of feeding maize silage at different times before the herbage meal on dry matter (DM) intake, milksolids (MS) production and nitrogen (N) excretion of late lactation dairy cows. In an indoor study, nine Friesian {\texttimes} Jersey dairy cows were assigned to three treatments: (1) herbage only (control); (2) supplemented with 3 kg DM of maize silage after morning milking approximately nine hours before the herbage meal (9BH); and (3) supplemented with 3 kg DM of maize silage after afternoon milking approximately one hour before the herbage meal (1BH). Cows were offered ad libitum cut herbage (perennial ryegrass-white clover) for five hours from 1530 to 2030 h. Herbage DM intake was greater (P=0.03) for control than 1BH cows, but did not differ between control and 9BH or between 1BH and 9BH cows (13.71, 11.96 and 12.74 kg DM/cow/ day for control, 1BH and 9BH, respectively). The substitution of herbage by maize silage was greater (P=0.05) for 1BH than 9BH cows (0.56 vs 0.31 kg DM herbage per kg DM maize silage, respectively). Milksolids production did not differ between treatments (overall mean 1.33 kg MS/cow/day). Nitrogen concentration in faeces and estimated urinary-N excretion (g/day) were lower in supplemented than control cows. Under herbage restriction, it is important to consider time of maize silage supplementation relative to the herbage meal for managing substitution rate and urinary-N excretion.}, issn = {1176-5283}, author = {Al-marashdeh O and Greenwood SL and Hodge S and Edwards GR} } @conference {3672, title = {Estimation of a premium for milk with a high concentration of unsaturated fatty acids based on farm and processor profit: A simulation study.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {54-59}, address = {Dunedin}, abstract = { The objective of this study was to determine, via simulation, the premium required for dairy farmers supplying milk with a high concentration of unsaturated fatty acids (UFA) to a dairy processor to equal the operating profit ($/ha) of average farms, under New Zealand conditions. Fifty average farms (AVE farms) and fifty farms that fed an oilseed supplement to dairy cows (UFA farms) were simulated. The processing of milk produced by AVE farms and UFA farms into skim-milk powder and butter was also simulated. The physical and financial characteristics of dairy farms and a dairy processor were investigated under two scenarios: 1) no premium for UFA and 2) a premium for UFA which equalled the operating profit ($/ha) of UFA farms to that of AVE farms. UFA farms were not different from AVE farms in yields of milk, milkfat and protein, but their farm expenses were greater (P<0.05) than for AVE farms. A premium of $0.15/kg milkfat (for each 0.1 g UFA/100 g milkfat increase) was necessary for UFA farms to have an operating profit ($/ha) similar to AVE farms. These results may be used to further evaluate the impact of modifying milkfat UFA concentration at the farm level.}, issn = {1176-5283}, author = {Silva-Villacorta D and Lopez-Villalobos N and Hickson RE and Blair H and MacGibbon A} } @conference {3672, title = {Estimation of breed and heterosis effects for milk traits and somatic cell scores in cows milked once and twice daily in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {60-63}, address = {Dunedin}, abstract = { Crossbreeding is widely used by famers milking twice-a-day (TAD) to increase farm profitability. Effects of crossbreeding on farm productivity and profitability have not been investigated in farms practicing once-a-day (OAD) milking. The aim of the study was to estimate breed and heterosis effects for lactation length (LL), total yields of milk (MY), fat (FY) and protein (PY) and average somatic cell score (SCS) in cows milked OAD or TAD. Records from 36,276 Friesian (F), 31,560 Jersey (J) and 90,081 crossbred (F{\texttimes}J) cows that calved in spring between 2008 and 2012 were used. Compared to J cows, F cows had a higher MY (657 kg in OAD and 1034 kg in TAD), FY (2.9 kg in OAD and 7.8 kg in TAD), PY (13.6 kg in OAD and 22.4 kg in TAD) and SCS (0.28 in OAD and 0.05 TAD). Lactation length in OAD cows was five days shorter than in TAD cows (P<0.05). These results show a significant interaction between breed and milking frequency for production traits (P<0.001). Expressed as a percentage of the average of parental breeds, first-cross heterosis effects ranged between 4.92 to 6.84\% for production traits, and were similar across milking frequencies. The estimates of breed and heterosis obtained in this study can be used for simulation studies to evaluate the profitability of crossbreeding systems under OAD and TAD milking systems of typical New Zealand dairy farms.}, issn = {1176-5283}, author = {Lembeye F and Lopez-Villalobos N and Burke JL and Davis SR} } @conference {3672, title = {Estimation of crossbreeding effects on yields of dairy products and value of milk processed in different product portfo}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {48-53}, address = {Dunedin}, abstract = { The international market requires milk products to meet specified minimum standards that define acceptable composition. This study used a deterministic simulation model to estimate milk products yields of individual cows for different export markets. Four milk product portfolios were analysed which included 100\% of the milk to either whole-milk powder (WMP), skim-milk powder, cheese, or butter. Milk product potential was estimated for 4310 mixed-breed heifers from LIC Sire Proving Scheme herds based on total lactation production. Lactation lengths were 212, 214 and 213 days for Holstein Friesian (HF), Holstein Friesian-Jersey crossbreds (HFxJ), and Jerseys (J) respectively. Milk yields were significantly different between breeds averaging 3121 for HF, 2947 for HFxJ, and 2751 litres for J cows. Holstein Friesians had the lowest fat, protein and lactose concentrations, whereas J had the highest. Holstein Friesian had the greatest yields of WMP per 1000 litres of milk, whereas J had the least. For all scenarios, J milk was most valuable per litre. Crossbred cows provided greater total milk income for all scenarios except 100\% butter. Positive heterosis effects were estimated for first-cross HFxJ animals for milk production and product yields. Crossbreeding produces cows with milk better suited to the processing requirements of the New Zealand dairy industry and returning greater value to the New Zealand dairy farmer.}, issn = {1176-5283}, author = {Sneddon NW and Lopez-Villalobos N and Hickson RE and Shalloo L and Garrick DJ} } @conference {3672, title = {Evaluation of production traits of red deer skins in the Deer Progeny Test.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {114-118}, address = {Dunedin}, abstract = { Skins, hides and leather from deer are a valuable co-product of New Zealand venison production. Measurement of skin traits was included in the Deer Progeny Test to evaluate options for genetic selection, and to determine if selection for other production traits risks diminishing the quality of deer skins and leather. Skins of slaughtered eleven-month-old progeny (n=310) from terminal (wapiti crossbred) and maternal (red) sire types were evaluated for 18 different quantitative and qualitative traits throughout processing to pearl-crust leather. All processing was carried out by New Zealand Light Leathers. All traits were analysed using least squares means models with sire as the random term and pre-slaughter live weight as a covariate. For all traits except evenness grade of the pearl-crust leather, the relationship with pre-slaughter live weight covariate was significant (p<0.05) and positive. Sire had a significant effect (p<0.01) on eight traits including critical strength and finished-leather attributes (p<0.01), farm was also significant for eight traits (p<0.01). Average skin thickness was similar to published values. Sire can have an effect on important traits, and selection for higher slaughter weights of yearling red deer is predicted overall to increase the quality of skins and leather produced.}, issn = {1176-5283}, author = {Ward JF and Mathias-Davis HC and Cooper SM and Crawford EM and Wheeler M and Asher GW} } @conference {3672, title = {Flexural limb deformities in a cohort of Thoroughbred foals on commercial stud farms}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {188-190}, address = {Dunedin}, abstract = { }, issn = {1176-5283}, author = {Shotton AK and Bolwell CF and Rogers CW and Gee EK and Sells PD and Connell J and McIlwraith CW} } @conference {3672, title = {From monitoring to precision phenotyping: towards a systemic use of precision livestock measures in dairy herds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {145-148}, address = {Dunedin}, abstract = { There is an untapped potential to combine the measures from precision livestock farming to provide improved, biologically meaningful, phenotypes. At present, it is generally the case that precision livestock solutions are developed for the purposes of monitoring one particular condition, and very often using only one measure. It has been shown that combinations of precision livestock measures may provide a fuller, and more robust, description of the condition. These may be both combinations of full continuous signals (e.g., milk yield and electrical conductivity) or sequential combinations. Sequential combinations are those in which a cheap, easy-to-deploy but usually less precise signal is used to provide first-level monitoring but is set up to initiate a second-level, more precise, and usually more expensive, monitoring when the first indicator indicates change from the normal state. The usefulness of combined measures benefit from being developed with a systemic view of the underlying biology, leading to a subsequent improvement in the precision of the resulting phenotypes. The deployment of combined measures for phenotyping is becoming increasingly important, particularly in the context of addressing more complex traits such as robustness in genomic selection and when considering the animal{\textquoteright}s role in herd level resilience.}, issn = {1176-5283}, author = {Friggens NC and Thorup VM} } @conference {3672, title = {Genetic parameters for meat yield and quality traits derived from the New Zealand Perendale progeny test}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {106-110}, address = {Dunedin}, abstract = { A catch phrase within animal genetics is that there is as much variation within a breed as there is between breeds. The New Zealand Perendale Progeny Test has been conducted on North and South Island sites since 2010 with the aim of investigating genetic variability for carcass traits. A total of 51 sires, from 27 studs have been assessed, with sires selected from the top 20\% of the Perendale across-flock Dual Purpose Index SIL evaluation. Within each year/site lambs generated were born within a week (ewes naturally synchronised pre-mating), and slaughtered on the same day. A total of 2318 male progeny have been generated and slaughtered through Alliance with traits measured including weight traits, carcass dimensions, VIAscan{\textregistered} traits, carcass pH, carcass fat colour and, in some years, colour stability of chilled aged loins, subjective marbling score and meat tenderness. Genetic parameters were estimated with ASREML; carcass weight was fitted as a co-variate for carcass traits (excluding carcass weight). The heritability estimates for all traits were moderate to high, with the lowest of 0.22 {\textpm} 0.07 for VIAscan{\textregistered} GR, and the highest, for pH, of 0.44 {\textpm} 0.09, with the majority between 0.22 and 0.43. The high estimate for slaughter plant measured pH was supported by the 0.59 {\textpm} 0.17 estimate for pH measured in the laboratory on those samples which were measured for colour stability. The phenotypic correlations between traits were generally well estimated with small standard errors for the majority of trait combinations. The genetic correlations were not as well estimated with standard errors greater than 0.10 for most traits combinations, but despite the large standard errors some were still significant, and in general agreement with values the literature. The progeny test has therefore demonstrated significant genetic variability for the range of carcass traits assessed in this study within the Perendale breed.}, issn = {1176-5283}, author = {PL Johnson and Young EA and Russenklau D and Anderson T and Dodds KG} } @conference {3672, title = {Growth rate and carcass characteristics of Simmental- and Angus-sired steers born to Angus and Angus-cross-dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {15-19}, address = {Dunedin}, abstract = { Traditionally, British breeds have been the main source of beef produced in New Zealand. Recently the use of dairy breeds has increased. This experiment evaluates the growth rate and carcass characteristics of steers (n=64) born to straightbred Angus (AA), Angus-cross-Holstein Friesian (AF), Angus-cross-Jersey (AJ) or Angus-cross-Kiwicross (AK) dams, and sired by Angus (A) or Simmental (S) bulls. This created eight crossbred treatments: A-AA (n=10), A-AF (n=9), A-AJ (n=10), A-AK (n=5), S-AA (n=11), S-AF (n=3), S-AJ (n=11) and S-AK (n=5). Live weight between 329 days of age and slaughter, and ultrasoundderived and slaughter-day carcass characteristics were measured. At 400 and 600 days of age, respectively, Simmental-sired steers were 22 kg and 37 kg heavier than Angus-sired steers (P<0.05). All steers had a similar intramuscular fat percentage (P>0.05). Simmental-sired steers had greater eye-muscle area than Angus-sired steers (P<0.05). Simmental-sired steers had heavier and longer carcasses, and greater dressing-out percentages than Angus-sired steers (P<0.05). Simmental sires produced fast-growing progeny with heavier carcasses than Angus sires for all dam lines. Angus-cross-dairy cows produced steer progeny with similar carcass characteristics to those from Angus cows bred with beef bulls.}, issn = {1176-5283}, author = {Collier KJD and Hickson RE and Schreurs NM and Martin NP and Kenyon PR and Morris ST} } @conference {3672, title = {How do you build a profitable beef cowherd?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {154-158}, address = {Dunedin}, abstract = { }, issn = {1176-5283}, author = {Leachman L} } @conference {3672, title = {The influence of hogget liveweight change during their first lactation on pregnancy rates at the subsequent breeding period}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {247-250}, address = {Dunedin}, abstract = { Breeding ewe lambs can have a negative effect on subsequent two-tooth breeding weights which may impact on subsequent reproductive rates. The impact of ewe lamb breeding can be alleviated by providing ewes with forages with high nutritive value such as lucerne or a herb mix such as chicory, plantain, red clover and white clover. In a study conducted over two breeding seasons ewe lambs were offered a ryegrass and white clover pasture, a herb mix or lucerne from one week prior to the expected start of lambing until weaning. The impact liveweight change during lactation, and from weaning until breeding as a two-tooth, on pregnancy and fecundity rates was examined}, issn = {1176-5283}, author = {Corner-Thomas RA and Morris ST and Kenyon PR} } @conference {3672, title = {The lying behaviour of non-lactating, pregnant dairy cows wintered in a loose-housed barn on woodchip bedding material}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {24-28}, address = {Dunedin}, abstract = { Winter represents an important time for dairy herds in the southern South Island of New Zealand. In an attempt to address poor performance in forage crop-based wintering systems, farmers are increasingly using off-paddock methods of wintering, such as housing their cows in barns. The aims of this study were to monitor the lying behaviour of cows wintered in a loose-housed barn with woodchip bedding during three separate seven day periods to determine (i) if recommended lying times were being met, and (ii) if bedding moisture content could be used as a predictor of lying time. Twenty-one non-lactating dairy cows were selected, based on age, body condition score and stage of pregnancy, from a housed herd of 90 mixed-age cows. Lying and standing movements were recorded at thirty second intervals using an electronic movement data logger attached to the ankle of each cow. Monitoring in Period 1 commenced four days after the cows entered the barn for wintering in early June; Period 2 occurred in early July, just prior to the removal and replacement of bedding material, and Period 3 occurred in mid-July when cows were again on fresh bedding material. Average daily lying times were two hours longer during Periods 1 and 3, when barn material was fresh (10.7 and 10.5 h/day, respectively), than when soiled during Period 2 (8.4 h/day). The difference in lying behaviour was due to a difference in the number of lying bouts: cows had fewer lying bouts during Period 2 (6.1 per day) than Periods 1 \& 3 (7.4 and 7.9 per day, respectively). The average moisture content of the bedding was 60.7, 68.4 and 64 .3 \% for Periods 1, 2 and 3, respectively. Bedding moisture content per se did not appear to be a good predictor of lying time, suggesting other factors such as bedding temperature and cleanliness and stage of pregnancy were influencing lying behaviour. These results are discussed in relation to bedding surface management and the welfare of housed dairy cows.}, issn = {1176-5283}, author = {Davison LJ and Dalley DE and Chrystal J and Monaghan R and Laurenson S and Stevens D and Wall A and Pigou J and Gorton A} } @conference {3672, title = {Milk production and urination behaviour of dairy cows grazing diverse and simple pasture}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {79-83}, address = {Dunedin}, abstract = { Milk production and urination patterns were measured for mid-lactation dairy cows grazing a simple perennial ryegrass-white clover pasture (n = 15) and a more diverse pasture (n = 15) containing herb (chicory and plantain) and legume (lucerne) species in addition to the perennial ryegrass and white clover. Milksolids production was similar for simple (2.09 kg MS/cow/d) and diverse (1.94 kg MS/cow/d) pasture. Urination volume and frequency were similar for simple (2.0 L/urination, 11.6 urinations/cow/d) and diverse (2.2 L/urination, 15.0 urinations/cow/d) pasture. Urine-nitrogen (N) concentration was 20\% lower for diverse (4.9 g N/L) than simple (6.1 g N/L) pasture. Diverse pastures may offer benefits for reducing the environmental impact of dairy farming by reducing the N loading of urine patches.}, issn = {1176-5283}, author = {Edwards GR and Bryant RH and Smith N and Hague H and Ferris A and Farell L} } @conference {3672, title = {Modelling the effect of more lambs, faster growth and heavier carcasses on feed conversion efficiency and seasonality of demand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {9-14}, address = {Dunedin}, abstract = { Feed conversion efficiency (FCE) and seasonality of feed demand were assessed within a demand-driven deterministic steadystate model of a sheep livestock system. Weekly animal feed demands were simulated within ExcelTM. Overall flock structure and seasonality of demand were then determined using linear programming. Key inputs were individual animal energy requirements (MJME) for maintenance, pregnancy, lactation and growth. Whole-of-system FCE was measured as grams of meat carcass per MJME. Overall system output was constrained by a fixed but arbitrary system limit of 10 million MJME. Increasing the lambing percentage from 110\% to 170\% increased FCE by 20\%, with less total system feed required during the pregnancy period but with more feed required post-weaning. Increasing pre-weaning liveweight gain from 250 g/day to 450 g/day increased FCE by only 1\%, but with a transfer of feed demand from post-weaning to pre-weaning. Increasing post-weaning liveweight gain from 100 g/day to 300 g/day increased FCE by 8\% with earlier slaughter reducing overall post-weaning requirements. Increasing carcass weight from 12 kg to 24 kg increased FCE by 28\%, with a major shift in feed demand from pre-weaning to post-weaning. Implications for improving pastoral sheep farm productivity and profitability are discussed.}, issn = {1176-5283}, author = {Klaassen PL and Woodford KB and Trafford GM} } @conference {3672, title = {New Zealand case studies of automatic-milking-systems adoption}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {127-131}, address = {Dunedin}, abstract = {Case studies were undertaken of six New Zealand farmers who have adopted automatic milking systems (AMS). Data were collected during spring 2014. Farmer experience with AMS ranged from one to four years. Three farms were in the Waikato and three were in Canterbury. Two farms use barns with fully-confined cows, two use pasture-based systems with year-round pasture access, and two use hybrid systems where cows confinement for varying times depending on season. The key focus was on documenting farmer experience. All six farmers met innovator criteria and were driven by the challenge of making the system work. Farmers reported per cow production above their previous dairying experience and expectations. Cows-per-robot ranged from 50 to 80 and were higher on pasture systems where daily milkings per cow were lower relative to confined systems. Annual milksolids production ranged from 30,000 to 42,900 kg per robot. Total labour requirements did not always change but the type of labour did change. Initial training of cows was stressful for farmers and time consuming. Farmers emphasised that it was a total change of system requiring new ways of thinking. Farmers perceived capital cost as the major adoption constraint but remained positive about the future of AMS.}, issn = {1176-5283}, author = {Woodford KB and Brakenrig MH and Pangborn MC} } @conference {3672, title = {New Zealand Society of Animal Production {\textendash} The Past 25 Years}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {150-153}, address = {Dunedin}, abstract = { }, issn = {1176-5283}, author = {Nicol AM} } @conference {3672, title = {Nitrogen partitioning in sheep offered three perennial ryegrass cultivars at two allowances in spring and autumn}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {74-78}, address = {Dunedin}, abstract = { }, issn = {1176-5283}, author = {Jonker A and Cheng L and Edwards GR and Molano G and Taylor PS and Sonoval E and Cosgrove GP} } @conference {3672, title = {Phenotypic correlations among alternative definitions of feed efficiency in grazing lactating dairy cows across parities and lactation stages}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {34-38}, address = {Dunedin}, abstract = { The objective of this study was to estimate correlations among alternative measures of energy conversion efficiency and energy balance (EB) across parities and lactation stages in grazing lactating dairy cows. Individual measurements of net energy intake (NEI) (n=8,183) from pasture and concentrate from 2,693 lactations on 1,412 cows were available. Residual energy production (REP) was defined as net energy of lactation (NEL) minus predicted energy requirements; energy conversion efficiency (ECE) was defined as NEL divided by NEI; and EB was defined as the difference between NEI and energy required for both maintenance and lactation. Residual energy intake (REI) was defined as NEI minus predicted energy requirements. A strong correlation existed between REI and EB (0.88; P<0.05) for parity three or greater early lactation, weakening in parity one (0.70; P<0.05). These differences in correlations between REI and EB for animals across parities in early lactation, indicated primiparous animals were using body energy for milk production and growth; nevertheless, these strong correlations suggested negative REI animals (i.e., more efficient) are also in more-negative EB. Our findings suggest REI could be a valuable tool for future genetic improvement,}, issn = {1176-5283}, author = {Hurley AM and Lopez-Villalobos N and McParland S and Lewis E and Kennedy E and O{\textquoteright}Donovan M and Burke JL and Berry DP} } @conference {3672, title = {Preliminary linkage studies in sheep of keratin and keratin-associated protein genes with fleece weight, wool fibre diameter and fibre curvature}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, address = {Dunedin}, abstract = { A linkage study was conducted to detect variations in the genes for keratins and keratin-associated proteins (KRTAP) that might affect wool traits. To date 93 such genes have been identified in sheep: 85 of them (~91\%) are clustered in three chromosomal regions. Twenty-one genes are grouped within a 4-Mbp region on sheep chromosome 1 (OAR1), 28 within a 1-Mbp segment on chromosome 3 (OAR3), and 36 are clustered within a 1.3-Mbp site on chromosome 11 (OAR11). The DNA markers used in this work were single nucleotide polymorphisms (SNPs) dispersed throughout these keratin and KRTAP gene clusters. Markers were designed as three SNP-multiplexes: a 25-SNP, a 15-SNP and a 19-SNP multiplex for keratins/KRTAP regions on OAR1, OAR3 and OAR11, respectively. Resource animals came from eleven sire families whose progeny had been phenotyped for greasy fleece weight, washing yield, fibre curvature and diameter. Between 29 and 45 progeny per sire were genotyped with the three SNPmultiplexes. Linkage analyses on co-segregation of SNP alleles from sires with wool phenotypes of progeny were done across all the sires and within sire groups. Based on theoretical genome-wide threshold (F-value 10.13 and nominal P = 0.0016 for withinsire suggestive level), one family showed suggestive quantitative trait loci for greasy fleece weight on OAR1 and fibre diameter variability on OAR3. For these experimental animals, the results show no strong evidence of involvement of keratin and KRTAP genes in the wool characteristics analysed.}, issn = {1176-5283}, author = {Phua SH and Scobie DR and O{\textquoteright}Connell D and Henry H and Dodds KG and Brauning R and Clerens S} } @conference {3672, title = {Presidential Address 2014: The role of the New Zealand Society of Animal Production in the era of digital networks}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {1-2}, address = {Dunedin}, abstract = { }, issn = {1176-5283}, author = {Pacheco D} } @conference {3672, title = {The reasons farmers choose to dock lamb tails to certain lengths, or leave them intact}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {210-214}, address = {Dunedin}, abstract = { Compared to a survey carried out in 2005, New Zealand farmers appear to be docking fewer lamb tails flush (6\% vs. 22\%) and docking a greater number of lamb tails at 4-7 cm length (32\% vs. 16\%). The main reasons for docking were to minimize fly strike risk, reduce accumulation of dags and keep the crutching costs down. Farmers who docked lamb tails to a shorter length (3-4 cm) gave significantly (P<0.05) more importance to minimizing fly-strike, reducing the likelihood of dags and reducing the cost of crutching than any other reason. Farmers who docked lamb tails at a longer length (4-7 cm) gave significantly (P<0.05) more importance to meeting the processor requirements, minimizing euthanasia from uterine prolapse and minimizing fly-strike risk than any other reason. When farm performance characteristics, that may influence decisions relating to tail docking practices, were prioritised by farmers, preferences for minimizing deaths from fly-strike, improving weaning weight and making more money from the processor were greater than having fewer dag events, less euthanasia from rectal prolapses and less stress for the lamb at docking. These preferences did not differ among farmers that dock tails at different lengths or leave them intact.}, issn = {1176-5283}, author = {Kerslake JI and Bryne TJ and Behrent MJ and Maclennan G and Martin-Collado D} } @conference {3672, title = {Relationships among skin thickness, fat depth and eye muscle depth in sires and their progeny, and the breeding value for survival of their progeny}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {243-246}, address = {Dunedin}, abstract = { Lamb survival to weaning is an important determinant of farmer income and an animal welfare issue. The aim of this study was to determine whether skin thickness, fat depth and eye muscle depth (EMD) of the sires were related to skin thickness, fat depth, EMD and survival estimated breeding value (eBV) of their progeny. Data from a total of 19,436 lambs born between 2010 and 2013 inclusive were obtained from four farmers who comprise the Terminal Romneys for Increased Genetic Gain (TRIGG) group. Records included weaning weight, flock, sex, birth rank, date of birth, dam identity, sire identity and live weight at ultrasound measurement; skin thickness, fat depth and EMD measured using ultrasound at eight-months of age; and the survival eBV. Heritabilities for weaning weight, skin thickness, fat depth and EMD were 0.60{\textpm}0.08, 0.21{\textpm}0.07, 0.25{\textpm}0.08 and 0.61{\textpm}0.23 respectively. Skin thickness and EMD of the sire were positively correlated with progeny survival eBV while sire fat depth was negatively correlated with lamb survival eBV. Skin thickness, EMD and fat depth showed promise as indirect selection criteria for improved lamb survival. Additional data are required to confirm this.}, issn = {1176-5283}, author = {Tait IM and Hickson RE and Kenyon PR and Blair HT} } @conference {3672, title = {Remote sensing of heart rate and rumen temperature in feedlot beef cattle: associations with feeding and activity patterns}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {29-33}, address = {Dunedin}, abstract = { Heart rate (HR; beats/min) rumen temperature (RTMP; {\textordmasculine}C), activity level (ACT; \%) and feeding patterns (feeding event duration; sec/30 min, feed intake; kg/30 min, visits to the feeder; visits/30 min) have been suggested as feed efficiency (residual feed intake; RFI; kg/d), distress and health status indicators in cattle holding potential for development into practical on-farm decision making tools. Our study assessed the associations between these parameters when feedlot cattle (n=22) were eating or not eating (FI dataset), at differing activity levels (ACT dataset) and between feed efficient and feed inefficient cattle (RFI dataset). Heart rate was not different between FI, ACT and RFI groups. RTMP was lower in high ACT then low ACT observations (39.64{\textpm}0.15 vs 40.08{\textpm}0.15; P=0.001) and was associated with ACT in positive RFI cattle (r=-0.55; P <0.001). Activity levels in the ACT dataset were lower when cattle were located in the yard then when located in the pen or abattoir. Associations between RTMP and ACT across ACT and RFI datasets promote these as potential indicators of feed efficiency and health status in cattle. Changes in ACT across locations suggest it to be a potential indicator of distress. Future studies assessing RTMP and ACT abilities to determine performance are warranted.}, issn = {1176-5283}, author = {Munro JC and Schenkel FS and Miller SP and Tennessen T and Montanholi YR} } @conference {3672, title = {Ryegrass staggers and liveweight gain of ewe lambs and hoggets grazing four combinations of perennial ryegrass and strains of endophyte}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {175-178}, address = {Dunedin}, abstract = { Ryegrass staggers and live weight gain of Coopworth ewe lambs or hoggets were assessed over four eight week trials (two summer, two autumn) for four combinations of perennial ryegrass and strains of endophyte: Arrow with standard (SE, wild type) endophyte, Trojan with NEA3 endophyte, Trojan with a mixture of NEA2 and NEA3 endophytes, and Rohan with a mixture of NEA2 and NEA6 endophytes. In each trial, three replicates of 10 to 12 sheep were assigned to 0.3 ha plots of each cultivar x endophyte strain combination, with herbage mass reduced from 3-4000 kg DM/ha to 1500 kg DM during the eight weeks. Severe ryegrass staggers occurred in all four trials in Arrow SE, with a mean ryegrass staggers score ranging between 1.65 to 2.8 (0 to 5 scale). Minor ryegrass staggers occurred in Trojan NEA3, Trojan NEA2/3, Rohan NEA2/6 in two of the four trials, but only with a low mean score (<0.4). Live weight gain was lower in Arrow SE than the other cultivars in three of the four trials. Trojan NEA3 had live weight gain that was different from Trojan NEA2/3 (+27 g/head/day higher in Trojan NEA2/3) on one trial only. The perennial ryegrass cultivar x novel endophyte strain combinations Trojan NEA3, Trojan NEA2/3 and Rohan NEA2/6 showed liveweight gain that was similar or greater than the standard endophyte control, and caused minimal ryegrass staggers in {\textquoteleft}worstcase scenario{\textquoteright} conditions designed to induce this.}, issn = {1176-5283}, author = {Logan CM and Edwards GR and Kerr GA and Williams S} } @conference {3672, title = {The sheep dairy industry in New Zealand: a review}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {119-126}, address = {Dunedin}, abstract = { }, issn = {1176-5283}, author = {Peterson SW and Prichard C} } @conference {3672, title = {A snapshot of New Zealand farmers{\textquoteright} awareness of, and self-reported compliance with, animal welfare requirements}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {200-204}, address = {Dunedin}, abstract = { A 2012 telephone survey of 1565 farmers from across pastoral, pig and poultry livestock sectors aimed to benchmark farmer awareness of and self-reported compliance with the Animal Welfare Act 1999 and codes of welfare, and to explore the factors that drive or hinder that compliance. Eighty-two percent of respondents assessed their knowledge of statutory animal-welfare requirements as above average or excellent. However, of the five physical, health and behavioural needs of animals on which the legislation is based, only proper and sufficient food and water and adequate shelter were identified by more than half of respondents (77\% and 54\%, respectively). Once informed of the needs, 63\% considered it not difficult to provide for all five. The majority of respondents reported levels of compliance with statutory animal-welfare requirements above 85\% and knew of relevant examples of minimum standards from a code of welfare. The main barriers to providing for the needs of animals were identified as seasonal weather conditions [pastoral enterprises] and lack of money or resources [within the pork and poultry sectors]. In conclusion, while identification of statutory animal-welfare requirements was not high, farmers do understand the concepts that underpin the legislation.}, issn = {1176-5283}, author = {Williams VM and Pearson AB and Jeffrey GB and Mackenzie RW and Ward LJ and Fisher MW} } @conference {3672, title = {Stayability of beef-cross-dairy breeding cows to six years of age}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {159-163}, address = {Dunedin}, abstract = { The use of dairy-beef crosses is widespread throughout the New Zealand beef industry. Cattle originating from dairy herds make up 50 {\textendash} 55\% of New Zealand beef exports by weight (Morris \& Kenyon 2014). However, there is little information available regarding the use of beef-cross-dairy cows as breeding cows in terms of reproductive success and stayability in the herd. A study was conducted to investigate the pattern of cow culling and stayability from eight months of age until marking of the fifth calf of straight-bred Angus and Angus-cross-Friesian, Angus-cross-Jersey and Angus-cross-Kiwicross cows. The results showed that the stayability of these breeding cows was low, however, there were no differences in the stayability of straight-bred Angus or beefcross- dairy cows.}, issn = {1176-5283}, author = {Hickson RE and Corner-Thomas RA and Martin NP and Kenyon PR and Lopez-Villalobos N and Morris ST} } @conference {3672, title = {Transfers of genetic merit through multiple-tiered breeding structures into trait expressions for commercial sheep production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {97-100}, address = {Dunedin}, abstract = { In New Zealand, selection of both replacement females and sires based on performance is typically highly rudimentary in multiplier and commercial flocks. Selection of ewes and rams in these tiers is frequently driven by soundness and overall condition of selected animals and sometimes, based on whether or not the replacement candidate was born in a multiple litter. In breeder flocks, selection is usually supported by knowledge of the genetic merit of candidates. In multi-tiered breeding schemes, genetic progress is disseminated from the nucleus to the commercial tier through the transfer of males. Gene-flow principles can be applied in the optimization of multi-tiered breeding schemes, particularly to define the proportion of genetic superiority expressed in an individual, which also gets expressed in its descendants, in time, across tiers. The opportunity to increase the rate of progress and reduce the genetic lag between tiers in integrated production systems might be exploited by selecting candidates from which performance of the progeny can be predicted. The results of this simulation study demonstrate the long time delays of up to 25 years for genetic expressions to fully flow through a multiple-tiered breeding scheme. There was long time delay before genetic progress realised in the nucleus was achieved in the commercial flocks. For example, it was approximately fourteen years until 70\% of benefits of genetic improvement in lambing and slaughter traits were captured in the commercial flocks. This delay was mitigated when performance recording was implemented in the multiplier flock. This gain however, does not have the permanent and cumulative properties of genetic progress achieved in the nucleus flock, and so needs to be continued each year for the benefits to be maintained.}, issn = {1176-5283}, author = {Santos BFS and Byrne TJ and Amer PR and Gibson JP and Van der Werf JHJ} } @conference {3672, title = {Uncovering genetic variation in cow fertility using simulation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {42-47}, address = {Dunedin}, abstract = { Dairy cow fertility is currently measured using two traits: the proportion of cows mated within 21 days of the start of mating (PM21) and the proportion of cows that calve within 42 days of the start of calving (CR42). These traits indirectly measure a cow{\textquoteright}s genetic propensity to return to a fertile state after calving. Both PM21 and CR42 have low heritability (0.05 and 0.03, respectively) and fertility is suspected to have much stronger genetic drivers than indicated by these lowly heritable components. The purpose of this study was to explore genetic and environmental factors that contribute to dairy cow fertility using a stochastic simulation model. The model traces the reproductive life of cows from birth until their second calving date using environmental and genetic variables to simulate fertility phenotypes. The model demonstrated that even when significant genetic variation was simulated in underlying fertility traits, this variation appears only weakly as genetic effects using the current fertility traits evaluated for genetic selection purposes. Potential alternative traits (e.g. gestation length, heifer puberty trait, strength of oestrus expression or post-partum anoestrous interval) were shown to have potential to add value when identifying sires whose daughters calve earlier in the season.}, issn = {1176-5283}, author = {Dennis NA and Stachowicz K and Visser B and Hely FS and Amer PR and Meier S and Burke CR} } @conference {3672, title = {Urinary nitrogen excretion, grazing and urination behaviour of dairy heifers grazing pasture, chicory and plantain in autumn}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {70-73}, address = {Dunedin}, abstract = { The objective of this study was to investigate urinary nitrogen (N) excretion, grazing and urination behaviour of dairy heifers grazing pasture, chicory and plantain. A 35-day trial was conducted with 56 Friesian x Jersey heifers aged 9-10 months. Heifers were blocked into five treatments balanced for their live weight and breeding worth: 100\% ryegrass/white-clover pasture (PA; n = 12); 100\% chicory (CH; n = 10); 100\% plantain (PL; n = 12); 50\% pasture + 50\% chicory (PA+CH; n = 10); and 50\% pasture + 50\% plantain (PA+PL; n = 12). Feed was offered every three days with allowance calculated according to feed requirement for maintenance plus live weight gain of 0.8 kg/day. Measured urinary-N concentration, estimated daily urinary-N excretion (UN) and urinary output were similar among treatments. During the first six hours after feed allocation, heifers spent more time idling and less time ruminating on CH and PL than on PA. The CH and PA+CH groups urinated more frequently than other groups. Data from this study indicate that heifers grazed chicory urinated more frequently without increasing daily UN and may potentially reduce N loading from soil. Future study is needed to take account of urinary N excretion diurnal variation.}, issn = {1176-5283}, author = {Cheng L and McCormick J and Hussein AN and Fraslin C and Moonsan Y and Moonsan P and Logan C and Grabot J and Edwards GR} } @conference {3672, title = {Use of a urine meter to detect variation in urination behaviour of dairy cows on winter crops}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {84-88}, address = {Dunedin}, abstract = { Nitrate leaching loss from urine patches is predicted using a number of variables including urine N concentration, number of urine patches produced, and urine patch size however, there is a lack of quantitative data on the variability of urination events. A study was conducted using two wintering systems at Ashley Dene, Lincoln, between June and July 2014. Wintering systems were either kale (KA) fed at an allowance of 14 kg DM/cow/day plus barley straw (3 kg DM/cow/day) (n=5), or fodder beet (FB) fed at an allowance of 8 kg DM/cow/day, plus ryegrass baleage (6 kg DM/cow/day) (n=7). Twelve pregnant, non-lactating Holstein- Friesian x Jersey cows were fitted with calibrated urine meters which measured volume and frequency of urination events. The meters were worn for 24-hour periods. A calibration equation was used to calculate urine patch coverage from measured urine patch areas in the field and urine volumes. There was large variation between animals for urination behaviour. Average urination volume was similar for KA and FB (2.37 L/event; P>0.1 SEM=0.29), however urination frequency (12 vs. 8 events/day; P<0.1 SEM=2.25) and daily total urine volume (30 vs. 18 litres; P<0.03, SEM=4.56) were greater for KA. Average urine patch area was also 1.8 times larger on KA than on FB (0.47 vs. 0.25 m2). This information will be used to help predict nitrate leaching losses from grazing systems.}, issn = {1176-5283}, author = {Ravera BL and Bryant RH and Cameron KC and Di HJ and Edwards GR and Smith N} } @conference {3672, title = {The use of herb mix and lucerne to increase growth rates of dairy heifers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {132-135}, address = {Dunedin}, abstract = { Approximately 53\% of 6-month-old dairy heifers in New Zealand do not meet liveweight targets, partially due to inadequate growth rates in their first summer. The aim of this experiment was to determine the effect of feeding forage crops on the growth rate of dairy heifers over this critical period. Sixty six-month-old dairy heifers grazed one of three treatments: pasture, lucerne or a mixed-herb crop for a 63-day period. Both lucerne- and crop-fed heifers had similar (P>0.05) average daily liveweight gain (0.80 {\textpm} 0.02 and 0.75 {\textpm} 0.02 kg/day, respectively) and were greater (P<0.05) than those of pasture-fed heifers (0.53 {\textpm} 0.02 kg/ day). Lucerne-fed heifers had a greater (P<0.05) increase in body length (18.4 {\textpm} 1.3 cm) than heifers fed pasture (14.7 {\textpm} 1.2 cm). Heifers fed lucerne had higher (P<0.05) concentrations of urea in plasma (4.9 {\textpm} 0.1 mmol/L) compared with heifers fed crop (4.1 {\textpm} 0.1 mmol/L), which had greater (P<0.05) concentrations of urea in plasma than heifers fed pasture (2.5 {\textpm} 0.1 mmol/L). Feeding a mixed-herb crop or lucerne during the summer period resulted in higher growth rates of dairy heifer calves compared with feeding them pasture.}, issn = {1176-5283}, author = {Handcock RC and Hickson RE and Back PJ} } @conference {3672, title = {Using polymerase chain reaction to identify Streptococcus uberis in bovine milk: how does it compare with bacterial culture?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {20-23}, address = {Dunedin}, abstract = { Rapid identification of the pathogen responsible for an intramammary infection in a dairy cow can support herd management decisions. Polymerase chain reaction (PCR) has become available to identify mastitis pathogens in milk, offering a rapid and sensitive test. The performance of a commercial, real-time PCR assay was compared with traditional bacterial culture for the identification of the most-frequent pathogen in New Zealand, Streptococcus uberis, during three stages of lactation. Aseptically collected quarter-milk samples (n=6,848) were analysed by culture, and a subset (n=315) selected for PCR analysis based on S. uberis infection status. Using culture as the reference test, PCR had a relative sensitivity of 89.0\%, and a specificity of 64.3\% (kappa=0.49) for detecting S. uberis in milk collected at the first milking post-calving. The relative sensitivity and specificity for samples collected in mid-late lactation were 89.3\% and 97.7\%, respectively, indicating a greater agreement between the two tests later in lactation (kappa=0.88). Accurate diagnostic tests are necessary for mastitis management. In early lactation, when S. uberis prevalence is high, bacterial culture should be used. The PCR assay tested in this study is most useful after the first month of lactation.}, issn = {1176-5283}, author = {Steele NM and Williamson JH and Laven RA and Hillerton JE} } @conference {3678, title = {Alternative forages for livestock production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {85}, address = {Napier}, abstract = {In the New Zealand sheep, dairy and beef cattle industries, pastures are predominantly perennial ryegrass-white clover with some brassica and maize crops grown. There has, however, been increased interest in pure swards of alternative legumes such as lucerne and red clover, or forage herbs such as plantain and chicory.}, issn = {1176-5283}, author = {Morris ST and Kenyon PR} } @conference {3678, title = {Alternative method to measure herbage dry matter (DM) mass in plantain and chicory mixed swards grazed by lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {115-120}, address = {Napier}, abstract = {Calibration equations are available to determine the dry matter (DM) mass of pasture using either sward height or plate meter readings. Currently there are no methods available for determining DM in a herb-clover mix other than using quadrat cuts. The objective of this research was to determine the relationships between herbage DM mass as measured by quadrat cuts vs sward height and plate meter readings for herb-clover mixes during four seasons from early spring to autumn. Pre- and post-grazing herbage DM masses (kg/ha) in the plantain mix (plantain (Plantago lanceolata), white clover (Trifolium repens) and red clover (T. pratense)) and in the chicory mix (plantain, chicory (Cichorium intybus), white clover and red clover) were estimated by collecting quadrat cuts. For each quadrat cut, a plate meter reading and five sward height measurements were also recorded. Separate regression equations were then developed for quadrat herbage DM mass vs sward height and plate meter readings. In addition, data from the plantain and Chicory mixes were pooled to obtain a data set for a combined herb-clover mix. The individual R 2 values were significant for all three relationships and ranged from 0.49 to 0.86. The concordance correlation coefficient (CCC) for all three relationships fell between 0.56 and 0.94. The relative prediction error (RPE) for all three relationships varied between 18 and 29\%. The regression equations developed by these non destructive methods, would enable farmers to obtain a reliable estimate of the herbage DM mass, with a level of precision sufficient for making day-to-day grazing management decisions on farm. The data do suggest different regression equations need to be utilised for different seasons of the year.}, issn = {1176-5283}, author = {Somasiri SC and Kenyon PR and Morel PCH and Kemp PD and Morris ST} } @conference {3672, title = {Assessing the meat quality of venison short-loin from farmed red deer using visible-near infrared spectroscopy}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {17-22}, address = {Napier}, abstract = {Venison from red deer (Cervus elaphus) is marketed as a premium quality, healthy red meat. Ideally, meat-quality attributes need to be measured prior to sale. Near infrared spectroscopy (NIRS) has potential for the measurement of sensory, nutritional and technological parameters in beef, but its use on venison has not yet been considered. The aim was to evaluate NIRS for predicting Warner-Bratzler shear-force parameters, meat colour, ultimate pH, sarcomere length and water holding capacity of venison short-loins. Samples were halved, vacuum packaged, aged for either 3 or 42 d at 1{\textpm}1{\textdegree}C and frozen, then defrosted for meat-quality assessment and acquisition of spectral data. In total, 154 samples (3 and 42 d aged) were divided into calibration (75\%) and validation datasets (25\%). Using partial-least squares regression, calibration equations were tested on the validation dataset. Prediction accuracies ranged from R2 =8.3\%, (SEpred =2.42) for meat lightness to R2 =66.6\%, (SEpred =0.10) for ultimate pH, suggesting that NIRS maybe useful for predicting some venison quality parameters.}, issn = {1176-5283}, author = {Craigie CR and Purchas RW and Maltin CA and Roehe R and Morris ST} } @conference {3678, title = {BRIEF COMMUNICATION: An evaluation of the sensory traits of venison}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {226-228}, address = {Napier}, abstract = {New Zealand venison is a well-regarded export product in Europe and quality is a key philosophy of the deer industry. As production targets increase understanding consumer preferences is important to ensure the eating quality of venison is maintained alongside these goals. Using data available from the Deer Progeny Test (Ward et al. 2014) this study aims to assess the quality of data from a sensory evaluation and investigate relationships between sensory traits and the overall acceptability of venison...}, issn = {1176-5283}, author = {Mathias-Davis HC and Ward JF and Dodds KG and Everett-Hincks JM and Maclennan G} } @conference {3678, title = {BRIEF COMMUNICATION: An exploratory investigation of the effects of selection for divergence in methane emissions on rumen digesta and carcass traits in 8-month old sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {142-144}, address = {Napier}, abstract = {Global agriculture accounts for approximately 14\% of anthropogenic emissions. In New Zealand, methane emissions from ruminants comprise 31.5\% of the total emissions (Ministry for Environment 2009), therefore, any future mitigation of emissions could have substantial economic implications for the agricultural sector. Reducing emissions from ruminant livestock without affecting animal production against a rising demand for animal products is challenging (Clark 2009). Measurements carried out over the last 15 years have shown a common feature of individual animal variation in methane emissions (Pinares-Pati{\~n}o et al. 2011b). Recently it has been shown that enteric methane emissions from sheep are both heritable and repeatable (gCH4/day 0.29 {\textpm} 0.05; repeatability 0.26 {\textpm} 0.02), whether expressed as gross emissions (g/d) or methane yield (emissions per unit of feed dry matter intake, g/kgDMI; Pinares-Pati{\~n}o et al. 2013). This makes breeding an attractive mitigation strategy for the lowering of enteric emissions from ruminant livestock given animal production performance is not affected (Pinares-Pati{\~n}o et al. 2011a)...}, issn = {1176-5283}, author = {Elmes SN and Bain WE and Greer GJ and Hickey SM and Young EA and Pickering NK and Rowe SJ and Knowler KJ and Pinares-Pati{\~n}o CS and McEwan JC} } @conference {3678, title = {BRIEF COMMUNICATION: Analysis of the on-farm cost of ovine pleurisy}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {62-64}, address = {Napier}, abstract = {Pleurisy is the result of an inflammation of the pleura producing fibrous adhesions between the lung and chest wall. In New Zealand (NZ) sheep, it has a substantial impact in terms of lost revenue, animal health and welfare, and in 2006 its cost was estimated at NZ$25.1 million (95\% CI=NZ$10.2{\textendash}48.1; Goodwin-Ray et al. 2008). Little is known about how to diagnose the disease prior to slaughter, although a NZ sheep industry report (Goodwin-Ray 2006) describes a {\textquotedblleft}pneumonia-pleurisy complex{\textquotedblright}, based on the findings of McGowan et al. (1978), Davies (1985) and Pfeffer (1986). Goodwin-Ray (2006) concludes that this complex has a poorly defined aetiology, likely reflecting the observation by McGowan et al. (1978) that some, but not all lambs with enzootic pneumonia, went on to develop pleurisy. In effect there is no evidence of an absolute link between pneumonia and pleurisy}, issn = {1176-5283}, author = {Hickford JGH and Hodge S and Bates JR and Hogan AK} } @conference {3678, title = {BRIEF COMMUNICATION: Are fetal programming effects, due to maternal early pregnancy nutrition, evident in adult male offspring in sheep?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {209-211}, address = {Napier}, abstract = {Manipulation of fetal development processes via maternal nutritional intervention can affect the physiology and cellular function of adult offspring through a process known as fetal programming (Harding \& Johnson 1995). Nutritional status of the dam in the first trimester of pregnancy is crucial to fetal development because, although fetal energy requirements in early pregnancy are relatively small, and thus, total nutrient demand is typically low, fetal metabolic activity is very high and organogenesis is occurring (Harding \& Johnson 1995)...}, issn = {1176-5283}, author = {Pain SJ and Asmad K and Fermin LM and Kenyon PR and Blair HT} } @conference {3678, title = {BRIEF COMMUNICATION: Comparison of early embryo development in Cheviot and Suffolk breeds of sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {202-204}, address = {Napier}, abstract = {Maternal constraint is the major non-genetic factor determining the size of the fetus at term (Gluckman \& Hanson 2004). Previous studies in various animal models have reported the effect of maternal size on birth size and postnatal growth, (Allen et al. 2002; Gardner et al. 2007) whereby fetal development and birth weight are reduced in a restricted maternal uterine environment, while enhanced in a luxurious uterine environment...}, issn = {1176-5283}, author = {Fermin LM and Pain SJ and Blair HT and Kenyon PR} } @conference {3678, title = {BRIEF COMMUNICATION: Dairy Extension}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {184-185}, address = {Napier}, abstract = {Growth has characterised the dairy industry since the 1990s. From 1992 to 2012 the industry doubled its occupation of total grasslands in New Zealand and increased cow numbers to be on par with the national population. Almost half of all stock units in this country are now dairy cows. ...}, issn = {1176-5283}, author = {Payne MS} } @conference {3728, title = {BRIEF COMMUNICATION: Developmental programming in sheep due to early pregnancy nutrition alters milk yields of adult female offspring but not of grand-offspring}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {212-214}, address = {Napier}, abstract = {Two long-term studies by our group have shown that nutrition of the pregnant dam altered the growth and development of the ewe offspring, and their subsequent lactational performance (van der Linden et al. 2009; Paten et al. 2013a). These effects were attributed to developmental programming possibly via epigenetic changes. Epigenetic regulation, such as histone modifications and chromatin condensation, has been implicated in the short- and long-term control of transcription in mammary epithelial cells (Kress et al. 2010)...}, issn = {1176-5283}, author = {Peterson SW and Pain SJ and Jenkinson CMC and Kenyon PR and Blair HT} } @conference {3678, title = {BRIEF COMMUNICATION: Does feeding level of ewe lambs affect their response to vasectomised rams?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {76-78}, address = {Napier}, abstract = {Exposure of ewe lambs (also known as hoggets or yearlings) to vasectomised rams (teasing) has increased breeding activity early in the breeding period in some but not all studies (Hudgens et al. 1987; Kemp et al. 1991; Ungerfled 2007; Cave et al. 2012; Kenyon et al. 2012, 2014). Additional effects reported include increased overall pregnancy rates and number of foetuses per ewe lamb (Kenyon et al. 2014). It would be of benefit if the cause of the variation among studies in the ewe lamb response to teasing could be identified. In mature ewes, nutrition has been reported to influence the teasing response when it is used to advance the breeding season (Scaramuzzi \& Martin, 2008). Therefore, the present study aimed to test the hypothesis that ewe lambs offered an unrestricted level of pastoral nutrition would have an enhanced response to teasing.}, issn = {1176-5283}, author = {Kenyon PR and Vi{\~n}oles C and Morris ST} } @conference {3678, title = {BRIEF COMMUNICATION: Effect of early life diet on lamb growth and organ development}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {205-208}, address = {Napier}, abstract = {Neonate lambs are pre-ruminants until approximately 3 {\textendash} 4 weeks of age (Treacher \& Caja 2002) and therefore their dam{\textquoteright}s milk is key to their survival and growth. During this period, their digestive system is relatively immature. Attempts have been made to evaluate the effects of early weaning on lamb growth performance with few data available at ages earlier than 4 weeks (Brown 1964; Large 1965; Walker \& Hunt 1981; Lane et al. 1986). These early studies show that lambs can be weaned at two to three weeks of age, however, they often result in growth rate checks. These findings suggest lambs require liquid diet for a minimum of two to three weeks. Nevertheless, rumen development is essential to enable lambs continue a normal growth trajectory when milk consumption ceases (Poe et al. 1969). Our objective was to examine the impacts on lamb growth and organ development when pellets are added to the milk diet of lambs in very early post birth life. Furthermore, lamb growth rates have improved by 50 g/day since the 1980s (Bray 2004). This may imply that the efficiency of lambs in utilising energy in their diet for growth and maintenance has altered. Thus, in addition to the growth performance, the utilisation of metabolisable energy (ME) in the diet for maintenance and growth was also examined.}, issn = {1176-5283}, author = {Danso AS and Morel PCH and Kenyon PR and Blair HT} } @conference {3678, title = {BRIEF COMMUNICATION: Ewe ultra-sound pregnancy diagnosis and its use by New Zealand farmers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {65-67}, address = {Napier}, abstract = {Ultra-sound pregnancy diagnosis can be a valuable management tool for sheep farmers. The benefits include early identification of non-pregnant (dry) ewes which can be culled, freeing up valuable feed for pregnant ewes (Blair 1986) and the identification of single, twin and triplet fetuses, allowing ewes to be fed based on their specific nutritional requirements during pregnancy (Garrick 1998). In addition, selection of lambing paddocks can be made based on the number of fetuses identified (Garrick 1998).}, issn = {1176-5283}, author = {Corner-Thomas RA and Kenyon PR and Morris ST and Ridler AL and Hickson RE and Greer AW and Logan CM and Blair HT} } @conference {3678, title = {BRIEF COMMUNICATION: Farmer Learning and Extension {\textendash} The Beef + Lamb New Zealand Approach}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {186-188}, address = {Napier}, abstract = {While the sheep and beef sector has faced considerable challenges over recent times, it remains New Zealand{\textquoteright}s second largest primary industry and export sector, contributing over $7 billion to the New Zealand economy each year. Importantly, the Red Meat Sector Strategy (RMSS), released in May 2011, defined a suite of initiatives that could be employed to grow the sector{\textquoteright}s economic contribution, and also to improve the profitability of all participants in the red meat value chain...}, issn = {1176-5283}, author = {Wakelin R and Champion S} } @conference {3678, title = {BRIEF COMMUNICATION: FarmIQ - Learning and extension around quality meat production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {189-190}, address = {Napier}, abstract = {FarmIQ was established in August 2010,following a successful bid to the Ministry for Primary Industries{\textquoteright} Primary Growth Partnership (PGP) fund. The partnership is between MPI and three significant farming industry entities {\textendash} Silver Fern Farms (SFF), Landcorp Farming Limited and Tru-Test Group.}, issn = {1176-5283}, author = {White T} } @conference {3678, title = {BRIEF COMMUNICATION: Genetic evaluation for milking performance in a large flock of milking sheep in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {55-57}, address = {Napier}, issn = {1176-5283}, author = {McMillan WH and McLachlan SJ and Hercus IS and Lopez-Villalobos N} } @conference {3678, title = {BRIEF COMMUNICATION: Grand-dam age has no effect on ram lamb live weight and carcass characteristics}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {196-198}, address = {Napier}, abstract = {Breeding ewe lambs at 7 to 9 months of age can increase their lifetime productivity and profitability (Young et al. 2010; Kenyon et al. 2011, 2014). Further, in theory, increased genetic gain can be made from selecting progeny born to ewe lambs as replacement ewes. However, little is actually known about the long-term phenotypic impacts of such a management option. Loureiro et al. (2012) examined the reproductive and lactational performance of 18-month-old ewes born to either ewe lambs or mature ewes and reported little difference. They did, however, report that in one of two years, lambs born to dams who themselves were born from ewe lambs (i.e., the grand-offspring) were slightly heavier at weaning than grand-offspring from mature ewes. If this apparent effect was found to be consistent after weaning, and also to affect carcass characteristics, it might indicate a potential advantage of selecting replacement ewes born to ewe lambs. To date, these relationships have not been examined. Therefore, the present study examined the live weight and carcass characteristics of two cohorts of male lambs born to ewes that themselves were born to either mature ewes or ewe lambs...}, issn = {1176-5283}, author = {Burnham DL and Kenyon PR and Pain SJ and Hickson RE and Blair HT} } @conference {3678, title = {BRIEF COMMUNICATION: High milk production in milked sheep grazed in large flocks in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {52-54}, address = {Napier}, abstract = {

There is a paucity of published information in New Zealand (NZ) sheep on milk production in commercial-scale dairy enterprises. Much of the early research involved small numbers of animals focused on traditional breeds, with the Dorset breed considered the most suitable dairy-type sheep (e.g., Geenty \& Jagusch 1974). Importation of East Friesian sheep in the mid-1990s provided new opportunities for sheep dairying (Allison 1996). Since that time, there appears to be a limited number of papers published in NZ on the milking performance of animals of East Friesian origin (e.g., Newman \& Steiffel 1999; Peterson et al. 2005)...

}, issn = {1176-5283}, author = {McMillan WH and McLachlan SJ and Hercus IS and Lopez-Villalobos N} } @conference {3678, title = {BRIEF COMMUNICATION: Inter-generational effects on male offspring born to ewes whose dams were offered varying feeding levels in pregnancy}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {199-201}, address = {Napier}, abstract = {There is a growing body of evidence to indicate that pregnancy nutrition can affect the productive performance of the offspring in sheep (Kenyon \& Blair 2014). Recently we demonstrated that pastoral-based feeding of the ewe (G0) can affect the milk production of the ewe offspring (G1) and the growth and live weight of the grand-offspring (G2) to weaning (van der Linden et al. 2009; Paten et al. 2013). An effect of feeding on grand-offspring is termed an inter-generational effect, and while these effects have been reported in species such as mice and rats, their occurrence in the sheep literature is rare. There is some evidence to suggest feeding of the ewe in pregnancy can alter the growth and carcass characteristics of her offspring (see review Greenwood et al. 2010) but there is no data available on potential inter-generational effects. The aim of the present study was to determine if feeding of the ewe (G0) in either early- or mid- to late-pregnancy could alter the live weight and slaughter characteristics of male grand (G2) offspring...}, issn = {1176-5283}, author = {Burnham DL and Kenyon PR and Pain SJ and Hickson RE and Peterson SW and Blair HT} } @conference {3678, title = {BRIEF COMMUNICATION: Methane emissions by sheep offered high sugar or conventional perennial ryegrass at two allowances}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {145-147}, address = {Napier}, abstract = {Perennial ryegrass (Lolium perenne L.) with a higher concentration of water-soluble carbohydrates (WSC) has been bred by plant breeders (Humphreys 1989). Ryegrass with a higher WSC can potentially alter rumen microbial fermentation, synchrony of energy and protein in the rumen, total energy supply to the animal and consequently productivity (Edwards et al. 2007). Methane originates mainly from rumen fermentation and is the main greenhouse-gas produced by New Zealand (NZ) agriculture (MfE 2013). The higher concentration of WSC in high sugar ryegrass (HSG) can change rumen fermentation patterns (Lee et al. 2003) and may consequently affect methane emissions. Methane emissions are largely driven by dry matter intake (DMI) (Hammond et al. 2013) and methane mitigation strategies are often more effective at a high DMI (Moe \& Tyrrell 1979). However, a true methane mitigation strategy should be effective at any DMI level. The objective of this study was to determine methane emissions from sheep fed freshly cut diploid HSG, conventional diploid ryegrass (CRG) and tetraploid ryegrass (TRG) offered at two levels of metabolisable energy for maintenance (MEm).}, issn = {1176-5283}, author = {Jonker A and Molano G and Sandoval E and Taylor PS and Antwi C and Cosgrove GP} } @conference {3678, title = {BRIEF COMMUNICATION: Milk production, live weight, body condition and somatic cell score during the first 150 days of lactation in Friesian, Jersey and crossbred cows milked once daily}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {46-48}, address = {Napier}, abstract = {Pasture-based dairy farming in New Zealand has predominately been with cows milked twice a day (TAD). However, since the last decades, milking once a day (OAD) has been adopted by some farmers in New Zealand for herd management and lifestyle benefits (Davis 2005)...}, issn = {1176-5283}, author = {Lambeye F and Lopez-Villalobos N and Burke JL and Davis SR} } @conference {3678, title = {BRIEF COMMUNICATION: Performance of lambs exposed to a desensitising regime prior to infection with Trichostrongylus colubriformis}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {73-75}, address = {Napier}, abstract = {Enhancing the immune response of lambs against the gastrointestinal nematode Trichostrongylus colubriformis through vaccination has been previously investigated (Windon et al. 1984; Douch 1989; McClure 2009). However, the majority of production loss from this parasite species in sheep has been attributed to components of the immune response (Greer et al. 2005). As such, manipulation of the host immune response through desensitisation may provide a novel method of reducing production loss associated with infection. The objective of this investigation was to evaluate the ability of a desensitising regime with parasite antigens to reduce the production cost associated with Trichostrongylus colubriformis infection in lambs...}, issn = {1176-5283}, author = {Greer AW and Huntley JF and Hogan A and Logan CM and McAnulty RW and McNeilly TN} } @conference {3678, title = {BRIEF COMMUNICATION: Predicting the impact of climate change on the risk of facial eczema outbreaks throughout New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {161-163}, address = {Napier}, abstract = {Facial eczema (FE) is caused by the sporidesmin toxin, which is produced by the spores of the fungus, Pithomyces chartarum (PC). Sporidesmin causes damage to the gut, liver and bile ducts in ruminants. This can result in weight loss, decreased production and skin photosensitivity which characterise clinical FE cases (Sheath et al. 1987; Towers \& Smith 1978). Production losses also occur in sub-clinical cases, which may go undetected under normal farm management.}, issn = {1176-5283}, author = {Dennis NA and Amer PR and Meier S} } @conference {3678, title = {BRIEF COMMUNICATION: Quality of meat from steers born to beef-cross-dairy cows and sired by Hereford bulls}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {229-232}, address = {Napier}, abstract = {The dairy industry is playing an increasing role in beef production in New Zealand. It is estimated that 65\% of the beef produced in New Zealand originates from dairy herds in the form of Friesian bull beef, first-cross dairy-beef cattle, or cull cows (Morris 2008). The dairy herd has a role in the generation of beef-cross-dairy breed heifers that are used as beef breeding cows. Dairy cattle genetics are not orientated towards meat production and this raises the question as to the suitability of beef-cross-dairy breed cows for producing progeny that are slaughtered for meat production. The quality of meat from the progeny of first-cross dairy-beef cows is largely unknown. The main dairy breed used in New Zealand is the Holstein-Friesian and the Jersey breed is also very predominant. To take advantage of hybrid vigour, the Friesian-Jersey cross is commonplace in the New Zealand dairy herd. The Friesian-Jersey cross is now considered as a breed in itself and called the {\textquotedblleft}Kiwi-cross{\textquotedblright} or {\textquotedblleft}Kiwi{\textquotedblright} breed (Garrick \& Lopez-Villalobos, 1998). Therefore, the objective of this study was to compare the quality of meat from steers which had an Angus (AA), Angus-cross-Friesian (AF), Angus-cross-Kiwi (AK) or Angus-cross-Jersey (AJ) dam. The steers were sired by Hereford bulls and so, the straight-bred Angus dams (AA) provided steers with beef-only genetics for comparison....}, issn = {1176-5283}, author = {Schreurs NM and Hickson RE and Coleman LW and Kenyon PR and Martin NP and Morris ST} } @conference {3678, title = {BRIEF COMMUNICATION: Reducing the risk of photosensitisation in dairy cattle undergoing a facial eczema challenge}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {158-160}, address = {Napier}, abstract = {Facial eczema (FE) is primarily a liver disease of ruminants that is caused by the ingestion of the toxin sporidesmin which is produced by spores of the fungus, Pithomyces chartarum. The liver and bile-duct injury may be monitored with a non-specific indicator, gamma-glutamyltransferase (GGT; Morris et al. (1990)). Dairy cattle may be assessed for their tolerance/susceptibility to sporidesmin by measuring their GGT activities in blood, about three weeks after a sporidesmin challenge. Under these conditions, logeGGT is heritable (0.34 {\textpm} 0.02), according to Cullen et al. (2011)...}, issn = {1176-5283}, author = {Cullen NG and Beatson PR and Lee RSF and Dobbie PM and Morris CA} } @conference {3678, title = {BRIEF COMMUNICATION: Relationships between longevity and herd-test traits in a dairy goat herd}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {49-51}, address = {Napier}, abstract = {Doe longevity has a significant impact upon the dairy goat industry. Does which maintain good health and high productivity, remaining in the herd for a greater number of years, will reduce the economic and environmental cost of raising replacement breeding animals per unit of milk production. Although longevity has been studied in sheep and dairy cattle (McIntyre et al. 2012, Harris \& Montgomerie 2007), there is little information regarding genetic parameters for longevity traits in New Zealand dairy goats. A study (Gautam 2012) has, however, investigated characteristics associated with the length of productive life of dairy goats in New Zealand...}, issn = {1176-5283}, author = {Wheeler N and Foote BJ and Foote JF} } @conference {3678, title = {BRIEF COMMUNICATION: Utilising a plantain, red clover and white clover mix - A farmer{\textquoteright}s perspective}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {73-75}, address = {Napier}, abstract = {Cheltenham Downs is located in the Manawatu district of the North Island of New Zealand. The farm was purchased by Landcorp in early 2011. It has a total area of 1427 ha, of which 1237 ha are effective. The farm is primarily utilised as a lamb-finishing enterprise. The property is located in a relatively summer safe area, with a mix of soil types (Rangitikei Sandy Loam and Milton, Te Arakure, Halcombe, Kiwitea, Ohakea, Milson and Manawatu Silt Loams) and has a flat to easy contour. The average rainfall is 1150mm per annum, evenly spread throughout the year. The majority of the farm is in ryegrass-white clover-based pastures. Each year, on average, 100 ha of Hunter brassica and 40 ha of kale are planted. Currently, the farm has 144 ha of the plantain, red clover and white clover mix.}, issn = {1176-5283}, author = {Brown IC and Morris ST and Kenyon PR} } @conference {3678, title = {Crossbred cows exceed production expectation in high producing herds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {41-45}, address = {Napier}, abstract = {New Zealand dairy production per cow has increased by over 33\% in the past fifteen years. Consequently, animal breeders are interested in understanding how expression of heterosis for dairy production traits is affected in higher-production systems. To investigate this question a natural-experiment approach was taken, utilising herd-testing records in the 2010-11 dairy production season in herds that contained two breeds, Holstein-Friesian cows ({\textquoteright}control{\textquoteright} breed) and Holstein-Friesian x Jersey cows ({\textquoteright}treatment{\textquoteright}). Herds were divided into two production system classes. The system classes were national-average herd production per cow ({\textquoteright}control{\textquoteright} system) and high per cow production ({\textquoteright}treatment{\textquoteright}). Per cow yields were over 45\% higher in the treatment herds than in national-average herds. Herd test records were analysed for 29,329 two-year-old heifers, and for 20,753 five-or six-year-old mature cows. Dependent variables for the statistical models were deviations from contemporary group means for 270-day yields for production traits. Explanatory variables included Breed, System, and individual cow Production Values as estimated in the national genetic-evaluation system (which include genetic, permanent environment and heterosis effects on yields). In the high-performance production systems the crossbred cows had higher yields than the Holstein-Friesian cows (compared with Production Value predictions) by 5.7 kg milksolids (heifers) and 1.9 kg milksolids (mature cows). This study indicates that heterosis for dairy production traits is more fully expressed in production systems that favour higher per cow yields than in the more restrictive production systems common in the 1990s.}, issn = {1176-5283}, author = {Montgomerie WA} } @conference {3672, title = {A cross-sectional survey of rider and horse demographics, and the feeding, health and management of Pony Club horses in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {11-16}, address = {Napier}, abstract = {A cross-sectional survey was conducted to describe rider and horse demographics, and the feeding, health, and management of horses and ponies involved with Pony Clubs in New Zealand. An online survey collected information from members of the New Zealand Pony Clubs Association between 1st November 2012 and 31st January 2013. A total of 502 respondents completed the survey. Most riders were female (95\%; 455/481) and were <=16 years of age (74\%; 357/481). Decisions on feeding and management of horses were rarely made by the rider alone (26\%; 124/476). The rider{\textquoteright}s parent or person responsible for the horse were often included in the decision-making, which occurred consistently across all age-groups <=16 years (P<0.001). Over half (53\%; 252/475) of the respondents{\textquoteright} families had more than 20 years of equine experience. On a scale of 1-9, the median body condition score (BCS) of the nominated Pony Club horses was six (interquartile range 5-6), and only 22\% (98/446) of respondents indicated that their horse was overweight (BCS >=7/9). More than 80\% of horses were managed on pasture throughout the year, with 24-hour access to grazing each day. In addition to pasture, 82\% (409/502) of respondents fed their horses a combination of commercially available equine feeds, including premixed feeds, cereals, and conserved forages. Overall, owners of Pony Club horses reported few health issues associated with their horse.}, issn = {1176-5283}, author = {Fernandes KA and Rogers CW and Gee EK and Bolwell CF and Thomas DG} } @conference {3729, title = {Dairy industry engagement in the setting and management of water quality limits}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {245-249}, address = {Napier}, abstract = {The progressive definition of water quality and quantity limits in catchments throughout New Zealand is a positive step towards improving the management of our freshwater resources. The process brings with it significant challenges for the sustainability and competitiveness of the dairy industry. In responding to these challenges, the dairy industry is working to develop a range of systems, resources and capability building programmes that will mitigate risks to the industry and support farmers through what is the largest shift in resource management in a generation. The dairy industry has defined a four-step model for engagement in the process. Essentially, the four steps can be considered to represent the setting of limits to address water quality issues, the definition of regulatory and non-regulatory methods to achieve those limits, managing to limits on farm, and the assessment of progress towards desired outcomes}, issn = {1176-5283}, author = {Scarsbrook MR} } @conference {3678, title = {Design and implementation of the Deer Progeny Test (DPT)}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {220-225}, address = {Napier}, issn = {1176-5283}, author = {Ward JF and Archer JA and Asher GW and Everett-Hincks JM and Mathias-Davis HC} } @conference {3678, title = {Evaluating new forage systems for East Coast dryland}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {108-114}, address = {Napier}, abstract = {Dry matter production and animal performance on plantain and erect annual clovers were monitored on four demonstration sites from 2012 to 2014. These studies confirmed plantain{\textquoteright}s potential for increasing both the quantity and quality of forage produced on cultivated and un-cultivatable hill country. Newly sown plantain produced more dry matter than newly-sown ryegrass over winter and spring. Across three sites, plantain pastures had more clover (32\%, 45\% and 45\%) in October. Lambs grew faster on plantain and had higher dressing-out percentages. Plantain appears less competitive than ryegrass and the grazing management it requires suits erect annual clovers (e.g. Balansa, Persian, Arrowleaf). Because these clovers are aerial seeders, achieving seed set is challenging under grazing. Until management systems can be developed to allow seed set, these clovers are destined to be an annual crop producing a bulk of high quality spring feed in suitable micro-climates. Plantain and erect annual clovers offer a promising alternative to ryegrass-based systems on dryland. However, there is much to learn about the best place for each species and how they fit within a farm system. As with lucerne, plantain and erect annual clovers need to be rotationally grazed to prevent damage to the crown and growing points. The success of these alternative forages in dryland will depend on farmer willingness to embrace new grazing management techniques.}, issn = {1176-5283}, author = {Macfarlane MJ and Thomson BC and Crofoot E and Hamilton G and Ashby H and Muir PD} } @conference {3678, title = {The Farmer Learning Project: Improving the design of agricultural extension to promote learning}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {166-172}, address = {Napier}, abstract = {New Zealand has played a key role in developing innovative extension models designed to support farmers to adopt new, evidence-based, farming practices. However, this momentum has been lost over recent years. A fresh and innovative model of extension is needed to ensure that New Zealand farmers learn about highly-effective technologies. The Farmer Learning Project, now in its third year, is a multi-disciplinary research venture that aims to find out how to promote farmers{\textquoteright} learning and adoption of evidence-based practices. This paper provides an overview of the Farmer Learning Project at Massey University and its innovations designed to promote learning about herb-mix pastures containing chicory, plantain and red and white clover. Five critical success factors shown to support the farmers{\textquoteright} learning are discussed. These include the importance of participation in a sustained and inquiry-focused farmer-scientist learning community, and their engagement in a variety of repeated and relevant learning experiences that are aligned to science. Underpinning these success factors are seven educational principles that need to inform design innovations in agricultural extension. Early findings are also shared from the second phase of the project, which investigates the farmers{\textquoteright} practice change as a result of their learning about herb pastures and its ability to create high performance sheep grazing systems.}, issn = {1176-5283}, author = {Sewell AM and Blair HT and Grey DI and Hartnett M and Kemp PD and Kenyon PR and Morris ST and Wood BA} } @conference {3678, title = {Farmer learning, successful technology transfer and agricultural extension}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {164-165}, address = {Napier}, abstract = {Agriculture has played and will continue to play an important role in the New Zealand economy. New Zealand earns $30 billion a year from its primary industries, which make up over 70\% of New Zealand{\textquoteright}s merchandise export earnings (Ministry for Primary Industries 2013). The primary sector as a whole had a 3.3\% annual compound growth rate during the period 1984 to 2007, while forestry was at 1.6\% and the wider economy at just 1.0\% (Morris 2013). Further, productivity of the primary industries has increased 2.5 times from 1978 to 2009, almost twice as much as the wider domestic economy (Ministry for Primary Industries 2013)...}, issn = {1176-5283}, author = {Kenyon PR and Morris ST and Corner-Thomas RA} } @conference {3729, title = {Farming within limits {\textendash} can system fundamentals be the key?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {241-244}, address = {Napier}, abstract = {The design of dairy systems with increased production and profit, but reduced environmental footprint, presents a problem with objectives that are seemingly at odds. We argue that this is why we have to go back to the ecological principles that underpin farm systems and use these to develop new systems that will achieve the above objectives. Healthy topsoil is a living nutrient trap. It requires long term thinking and action to achieve and maintain healthy topsoil. The rumen is a very complex ecosystem with the microbes as a key component. Farm systems aimed at optimal performance per cow, with lowest possible methane and urinary nitrogen waste products consistent with this performance, need to ensure effective rumen function. Maintenance dilution and cow longevity are important principles for sustainable and profitable farming. Pastoral livestock systems need ecological and financial buffers to remain resilient in uncertain times. We present a plan consisting of five strategies, based on some of these fundamentals, that we believe is a step towards farming profitably and within limits. }, issn = {1176-5283}, author = {Beukes PC and Romera AJ and Clark DA} } @conference {3729, title = {Farming within limits; the new reality. Concluding remarks}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {257-258}, address = {Napier}, abstract = {In 2002, Fish and Game New Zealand launched arguably one of the most successful environmental campaigns since the anti-nuclear movement which began in the 1950s. The {\textquoteleft}Dirty Dairying Campaign{\textquoteright} set the agricultural sector on a path to addressing its impact on the environment in a much more public and open forum than had been seen before. Within a generation, farmers have gone from receiving government funded incentives to increased stocking rates, cleared bush and scrub, and applied what we now know to be excessive amounts of fertiliser. They are now faced with the prospect of farming within limits imposed either naturally or by regulation.}, issn = {1176-5283}, author = {van Reenen EH} } @conference {3729, title = {Farming within limits; the new reality. Introductory remarks}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {241}, address = {Napier}, abstract = {The National Policy Statement for Freshwater Management establishes a range of policies directing local government to manage water sustainably in an integrated manner. A key purpose of the statement is to set enforceable quality and quantity limits that reflect local and national values allowing for economic growth to occur (Ministry for the Environment 2011). Limitations on resources will be the new reality for farmers, as is now the case in the Taupo and Rotorua catchments. This Contract Session will discuss the role of {\textquoteleft}system fundamentals{\textquoteright} in profitably farming within limits, the dairy industry response to improving the management of freshwater resources, a recent collaborative example of producing a mitigation resource for farmers, and the needs of resource constrained farmers from scientists in the next 20 years.}, issn = {1176-5283}, author = {van Reenen EH} } @conference {3678, title = {From Extension to Distributed Learning: The Embedding of Agricultural Scientists in Farmer Knowledge Networks}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {173-178}, address = {Napier}, abstract = {This paper reports on the social structures of an ongoing learning group in which 17 farmers and five agricultural scientists are collaboratively undertaking a three-year farmlet experiment that investigates the performance of {\textquoteleft}herb mix{\textquoteright} pastures. Network analyses have been undertaken of the history of prior contact between the group{\textquoteright}s 22 members and of the 223 contacts made by the participating farmers to develop their herb pasture knowledge. The results show that networking by farmer members radically increases the ability of science to reach other farmers. These farmer networks have distributed structures characterised by dense, decentralised and equitable ties between the participants. The power to authorise agricultural knowledge is pluralised by numerous self-reinforcing relationships grounded in everyday farming practices. The paper concludes by discussing the relevance of such distributed learning for current attempts to replace linear extension with a more productive approach to agricultural knowledge.}, issn = {1176-5283}, author = {Wood BA and Blair HT and Grey DI and Hartnett M and Kemp PD and Kenyon PR and Morris ST and Sewell AM} } @conference {3672, title = {Grazing behaviour, dry matter intake and urination patterns of dairy cows offered kale or fodder beet in winter}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {23-28}, address = {Napier}, abstract = {The opportunity to reduce nitrogen (N) losses to the environment from wintering systems for dairy cows may arise from a combination of restricted grazing systems and feeding low N diets to reduce N intake. Lack of information on urination behaviour and grazing intake during restricted grazing makes it difficult to predict animal and environmental responses. Three winter forage systems were simulated and pregnant, non-lactating Friesian x Jersey dairy cows were offered diets which varied in crop allowance and supplement: early sown-kale (EK) comprising 14 and 3 kg DM/cow/d of kale and barley straw; late-sown kale (LK) comprising 11 and 5 kg DM/cow/d of kale and green-chop oat silage; and fodder beet (FB) comprising 8 and 6 kg DM/cow/d fodder beet and grass baleage. Grazing behaviour, DM intake, DM utilisation and urination and faecal frequency, were recorded for six hours following morning crop allocation. After six hours, utilisation of EK, LK and FB crops were 82, 76 and 90\%, corresponding to respective DM intake rates of 1.9, 1.4 and 1.2 kg DM/cow/hr. Average urination frequency (2.7 urinations/cow) and duration (9.1 seconds/urination) during the six hour grazing bout was similar for all treatments, and urine N concentration was also similar for each treatment (2.22 g N/L). As cows consumed a high proportion (> 75\%) of their daily intake within six hours, and few urination events occurred during this period, the results indicate suitability for use of these systems in a restricted grazing regime combined with a standoff pad in order to mitigate losses of N to environment.}, issn = {1176-5283}, author = {Jenkinson BAB and Edwards GR and Bryant RH} } @conference {3677, title = {Growth rates of dairy heifers fed alternative feeds }, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {29-34}, address = {Napier}, abstract = {Dairy heifers need to achieve average daily gains (ADG) that allow them to reach liveweight targets. The aim of this experiment was to measure the effects of grazing 6-month-old dairy heifers on alternative feeds, over the summer period. Sixty 6-month-old Friesian-Jersey crossbred heifers were assigned to one of three treatments (pasture (P), conserved forages (C) or lucerne (L), with all treatments receiving supplementary meal. For the 6-week experiment, feed allowance was based on liveweight gain required to meet liveweight targets. Heifers were weighed at 0, 3 and 6 weeks of the treatment period. Wither height, crown-to-rump length and girth circumference were measured at the start and end of the experiment. L heifers had a greater (P<0.05) average daily gain (1.22 + 0.03 kg/day) than P heifers (0.57 + 0.03 kg/day), and C heifers were intermediate (0.78 + 0.03 kg/day). L and C heifers had a greater (P<0.01) increase in wither height (0.15 + 0.01 cm/day and 0.14 + 0.01 cm/day respectively) than P heifers (0.11 + 0.01 cm/day). L heifers had the greatest (P<0.05) increase in girth circumference (0.30 + 0.02 cm/day, compared with P and C heifers: 0.22 + 0.02 cm/day and 0.16 + 0.02 cm/day respectively). A combined diet of lucerne and meal during drought conditions increased ADG resulting in a greater proportion of heifers reaching liveweight targets.}, issn = {1176-5283}, author = {de Clifford RP and Hickson RE and Martin NP and Back PJ} } @conference {3678, title = {Induction of delayed-type hypersensitivity reactions to Candida albicans in pasture-based dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {233-238}, address = {Napier}, abstract = {Delayed-type hypersensitivity (DTH) reactions to Candida albicans are regularly used as an in-vivo indicator of cell-mediated immune function in cattle. Prior immunisation against C. albicans ensures a large clone of antigen-specific memory T cells, resulting in larger DTH responses and positive responses from a greater proportion of cows. Previous experimental results indicate that natural exposure to C. albicans is minimal in cows housed indoors and does not interfere with the interpretation of DTH responses to C. albicans in pre-immunised cows. However, housed cows may have different natural exposure to C. albicans than cows grazing fresh pasture outdoors. To determine if C. albicans is an appropriate antigen for inducing measurable DTH responses in pasture-based cows, DTH responses to C. albicans were assessed in ten cows pre- immunised with C. albicans and ten unimmunised control cows. A greater proportion of immunised versus unimmunised cows mounted a positive DTH response (90\% vs. 70\%), and responses were larger (P<0.01) and more variable (P<0.05) in immunised cows. Maximum relative double skinfold thickness increased 4.3 mm ({\textpm}0.7; SEM) and 1.4mm ({\textpm}0.2) in immunised and unimmunised cows, respectively. The results of this experiment suggest that pasture-based dairy cows in New Zealand have a low background exposure to C. albicans and pre-immunisation with C. albicans is required when using DTH responses as an indicator of cell-mediated immune function in pasture-based cows.}, issn = {1176-5283}, author = {McGowan JE and Hine BC and Mallard BA and Verkerk GA} } @conference {3672, title = {Is it time for changes in the New Zealand Society of Animal Production?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {1-4}, address = {Napier}, abstract = {At approximately ten year intervals, the President{\textquoteright}s address includes a review of society{\textquoteright}s activities (Andrews 1963; Everitt 1973; Smith 1984; Nicol 1992; Morrow 2004). Therefore, it is appropriate that I do so again. In addition, the society is facing the reality of falling paper numbers and attendance at conferences. Coinciding with this is a change in the generation of active scientific members within the society. Therefore, my address will also outline my thoughts on these issues moving forward.}, issn = {1176-5283}, author = {Kenyon PR} } @conference {3678, title = {Matching need with delivery: New Zealand farmer learning case studies}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {179-183}, address = {Napier}, abstract = {Effective farmer extension programs are needed for industry to capture the benefits of agricultural research. We describe three case studies adopting different delivery approaches to extension. Each case study was developed using key principles of adult learning, particularly the principle of learner-centred approaches where farmers are part of the design and development of workshops, tools and resources. The case studies are discussed in relation to the needs of the adult learner, including the need to know, self-concept, prior experience, readiness to learn, learning orientation and motivation to learn.}, issn = {1176-5283}, author = {Dynes RA and Brown MA and Bewsell D} } @conference {3729, title = {Menus of practice to improve water quality {\textendash} a Waikato example of collaboration in action}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {250-253}, address = {Napier}, abstract = {Water quality in the Waikato Region is highly variable, despite ongoing efforts from farmers, iwi, industry, local government and other stakeholders in the region. Intensive farming is a major contributor to areas of poor water quality. Levels of nitrogen in the region{\textquoteright}s waterways have been rising slowly but steadily over the last 20 years. Nitrogen in groundwater can take decades to emerge into surface water. Hence, this indicator of water quality will worsen before it improves. Levels of micro-organisms are moderate to high, but stable. Sediment levels are high in places, and phosphorus levels vary. Menus of good practice to improve water quality arose from direct requests by farmers and have been developed by collaborative effort between the Waikato Regional Council, research and industry bodies. They provide farmers and consultants with a decision support tool that is both scientifically rigorous, and flexible enough to meet the needs of individual farmers{\textquoteright} circumstances by providing an objective assessment of the relative benefits of a range of practices for their mitigation of nitrogen, phosphorus, sediment and bacterial discharges from farms. The procedures can also be used as a contribution to the review of the current Regional Plan.}, issn = {1176-5283}, author = {Abercrombie R} } @conference {3678, title = {Plants for dairy grazing systems operating under nitrate leaching limits}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {102-107}, address = {Napier}, abstract = {Regulations that place a limit on the amount of nitrate-nitrogen leaching from agricultural land are currently being developed by Regional Councils throughout New Zealand. These regulations may require substantial reductions in nitrate leaching from current typical dairy farm levels. Notions of the pasture plant {\textquoteleft}ideotype{\textquoteright}, which have previously emphasised pasture growth and the intake of digestible nutrients, should now also include characteristics which can reduce the nitrogen surplus in the animal, and, therefore, the amount of nitrogen (N) excreted in urine. Information on the critical external or internal N requirements of candidate pasture species could be used to develop hypotheses regarding future grazed forage systems; currently, there are few data available for this purpose. Recent empirical evidence indicates that diverse pastures incorporating forage herbs such as chicory and plantain can reduce total urinary N load while maintaining similar levels of herbage accumulation to ryegrass-white clover pasture. However, insufficient information is available to identify the mechanisms through which the urinary N reductions occur. This specific knowledge gap needs to be filled. In addition, more information is needed on the general nitrogen nutrition physiology of candidate pasture species for future forage systems.}, issn = {1176-5283}, author = {Chapman DF and Edwards GR and Pinxterhuis JB} } @conference {3678, title = {Practical implications of theoretical modelling of in-line milk meters}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {35-40}, address = {Napier}, abstract = {In-line milk meters are devices which measure the milk yield of dairy cows at every milking; however, they are also susceptible to error. This results in frequent, but inaccurate, measurements. This paper attempts to model a lactation curve and accumulated milk yields from these devices. Wood{\textquoteright}s model of a lactation curve was used to predict milk yield. This was modified by adding both systemic and random daily variation. The meters were modelled by taking the modified Wood{\textquoteright}s lactation curve for each cow and altering it with various error terms. Along with precision, each sensor also had a rate of drift, and a rate at which its variance grew. It was found that the precision of a sensor can be low, however by aggregating multiple records it is possible to obtain an accurate value for total yield. One strategy that improved the total yield accuracy was to scale the measurements obtained for a particular sensor in a given milking. Due to the uncertainty surrounding the errors involved, and the large assumptions that were made, this model is a good starting point for future work. It is able to identify the relative effect of errors on meter accuracy, and test strategies to improve accuracy of daily and total milk yield.}, issn = {1176-5283}, author = {Dowson O and Anderson G and Hempstalk K} } @conference {3678, title = {Predicting fleece weight from the difference in live weight pre- and post-shearing}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {68-72}, address = {Napier}, abstract = {Radio frequency identification (RFID) and automated weighing platforms facilitate the practicality and ease with which individual live weight (LW) can be recorded. This raises the possibility for the difference in recorded LW of sheep between pre- and post-shearing to provide an estimate of fleece weight (eFW) which, in turn, could allow selection pressure to be applied for improved wool production. The eFW of yearling ewes (n=98), yearling rams (n=274) and mixed-age ewes (n=305) were compared with their recorded fleece weight (FW). Positive linear correlations (P<0.001 for all stock classes) were observed between eFW and FW and also the eFW rank and FW rank. Although some variability between stock classes existed, for all data combined, FW rank was able to account for 42\% of the variation in eFW rank. Further, selecting individuals on eFW was able to retain an average of 64\% of the selection differential obtained using recorded FW. Overall, these results suggest eFW calculated from the difference in LW between pre- and post-shearing, in combination with RFID and automated weighing platforms, may provide a useful and practical tool to assist with selection for improved wool production in a commercial setting.}, issn = {1176-5283}, author = {Galway JM and Logan CM and Bywater AC and Greer AW} } @conference {3678, title = {Preference for different pasture grasses by horses in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {79-84}, address = {Napier}, abstract = {In New Zealand, grazed pasture is the primary nutrient source for equines, but little is known about equine grass preferences. A study to identify preferred grass species and/or cultivars (here on referred to as grasses) by horses was conducted in a 0.62 ha paddock containing 22 different test grasses. The grasses tested were planted in 6 x 3 m plots with four replicates of each species/cultivar. Four mature mares 527{\textpm} 38 kg, mean age 9 {\textpm} 3 years, were grazed on the trial plots for a total of five days during May 2007. Grass preference was quantified by; direct DM utilisation (pre- vs post-grazing dry matter cuts), pasture-probe measurement and visual assessment through photographs. Grass preference was similar for each method used to quantify utilisation (r2=0.73 {\textendash} 0.76 P<0.0001). The six grasses most preferred by horses were all tetraploid ryegrasses (DM utilisation 74\% (inter quartile range 67-81\%). Least-preferred grasses were Yorkshire fog and Cocksfoot (DM utilisation down -0.9 to -14\%). Hot water soluble carbohydrate and digestible organic matter in the dry matterwere the best predictors of grass preference. There was no significant effect of endophyte status (High, AR1, and Nil) on pasture preference during late autumn.}, issn = {1176-5283}, author = {Randall L and Rogers CW and Hoskin SO and Swainson NM} } @conference {3672, title = {Prevalence and risk factors for respiratory disease on Thorougbred and Standardbred stud farms in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {5-10}, address = {Napier}, abstract = {Respiratory disease has been identified as an important and production-limiting health problem on equine stud farms. This study aimed to describe the prevalence and risk factors for respiratory disease on commercial Thoroughbred and Standardbred stud farms in New Zealand, using logistic regression analysis. In 2012, 33 stud managers were interviewed regarding the 2010/11 and 2011/12 breeding seasons, including stud manager reported respiratory disease and strangles vaccination practices. Twenty-two stud mangers reported having respiratory disease on their stud farm in the 2010/11 breeding season, and twenty-six stud managers reported disease in the following season. On 90\% of stud farms, nasal discharge was reported by stud managers as the main sign of disease and on 41\% of stud farms no treatment was undertaken. When breeding season and the size of the stud farm were accounted for, vaccinating horses against strangles increased the odds of horses having experienced respiratory disease (OR 7.26, 95\% CI 1.48-35.64), while the presence of a stallion decreased the odds (OR 0.05, 95\% CI 0.004 - 0.48). This study has confirmed that respiratory disease is a common health issue on Thoroughbred and Standardbred stud farms in New Zealand.}, issn = {1176-5283}, author = {Rosanowski SM and Cogger N and Rogers CW and Bolwell CF} } @conference {3678, title = {Ramguard {\textendash} Increasing the Tolerance to Facial Eczema in New Zealand Sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {154-157}, address = {Napier}, abstract = {Facial eczema (FE) is a metabolic disease resulting primarily from damage to the liver and bile ducts. It is caused in ruminants by the effects of a mycotoxin, sporidesmin, produced by the fungus Pithomyces chartarum. The disease causes significant loss in agricultural production mainly in northern New Zealand. Sporidesmin toxin is produced in a laboratory and made available to those sheep breeders who wish to increase the level of FE tolerance in their flocks. The sheep industry in NZ has made steady progress towards increasing genetic tolerance to FE by testing potential future sires in ram-breeding flocks with an artificial challenge of sporidesmin. Ramguard provides the sporidesmin to breeders to dose their sheep at a specified dose-rate which is dependent on the level of tolerance already obtained. The Ramguard service has operated from August 1988 and has 60 clients dosing a total of 800 to 1100 rams each year. Most of the long-term-testing flocks are now using a dose rate six times higher than at the outset, which indicates animals in these flocks are tolerant to all but the severest outbreaks of FE. The heritability estimate for resistance to facial eczema is high at 0.45 {\textpm} 0.03.}, issn = {1176-5283}, author = {Amyes NC and Hawkes AD} } @conference {3678, title = {A review of recent research and extension on dryland lucerne in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {86-93}, address = {Napier}, abstract = {To maintain scientific integrity requires the publication of research articles in journals of high international standing. Results from such work are frequently discounted as irrelevant and of low value to practitioners wanting to interpret results for their farm situation. This creates a dilemma for funding bodies, scientists and industry good organizations. This paper outlines the strategy that has evolved to develop a dryland research programme based around lucerne. This aimed to satisfy the requirements of data integrity for excellent science output, yet maintain currency and relevance for wide-spread agricultural adoption. This utilized high quality science by a series of postgraduate students, and engaged industry good and Government organizations to provide funding support to demonstrate the key results, and for technology transfer. The successful adoption of information required the lead scientist to engage in all aspects of the science and extension. As the demands of each increased, digital technology in the form of a website, {\textquoteleft}txt{\textquoteright} alert service, and a blog were used to communicate to a wider audience and maintain accurate and timely advice. The development of a case study around {\textquoteleft}Bonavaree{\textquoteright} farm provided a focus for on-farm adoption and added currency and relevance to the scientific data. This allowed scientists, agribusiness professionals and on-farm practitioners to communicate with a farmer or scientist at a level that they felt most comfortable. The collective result has stimulated on-farm change to a greater extent than could be expected from a focus on any individual component of research, demonstration or technology transfer.}, issn = {1176-5283}, author = {Moot DJ} } @conference {3678, title = {Rumen Microbial Community Profiling as a Tool to Study Ruminant Production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {133-141}, address = {Napier}, abstract = {The species composition of the rumen microbial community is shaped by the ruminant host and by characteristics of the ingested feed. The microbes present determine the ratios of volatile fatty acids, gases such as methane, and microbial protein formed from the feed. The rate of feed fermentation and the mix of products are important for animal production and for environmental impacts of ruminant farming. Differences in microbial community composition within a cohort of animals on a specific feed indicate differences in the rumen environment and presumably host animal genetics or early life history. Differences in the community when animals are on different feeds can be used to understand the impact of the feed on rumen function. Interpreting these community differences relies on understanding what might cause the selection of one community type over another. Recent research in New Zealand has developed a pipeline for studying rumen microbial community compositions. These tools have been used to help understand the basis of lower methane emissions from sheep fed forage brassica compared to ryegrass, and to understand what drives natural variations in methane emissions from sheep. This type of analysis is also starting to be used to investigate productivity differences within animal cohorts.}, issn = {1176-5283}, author = {Janssen PH and Kittelmann S and Henderson G and Seedorf H} } @conference {3678, title = {Ruminant response to non-live probiotic microorganism extracts}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {148-153}, address = {Napier}, abstract = {Live probiotic microorganisms can improve ruminant productivity but results are variable and modes of action uncertain. Non-live microbial extracts provide insight into probiotic modes of action and their efficacy challenges the definition of probiotics. Twenty-two trials on lambs and ten on dairy cows were undertaken with non-live probiotic microorganism extract products RumenZyme Plus (RZP) and ProDairy (PD) respectively. Lambs treated with single or double doses of RZP tended to gain extra live weight relative to control with a 445 g median treatment response (P=0.001). The patterns of RZP results did not fit with an anti-inflammatory response alone but rather general productivity improvement. Cows receiving daily doses of PD had higher daily MS production with mean treatment response of 49.7 g/cow/day (P=0.008, 95\% confidence interval of 16.3 to 83.2 g/cow/day). There was no evidence of benefit from the addition of live probiotic lactic acid bacteria in these trials. Live lactic acid bacteria supplementation actually reduced response relative to the non-live probiotic extract in one dairy and two lamb trials (P<0.05). The results in this study demonstrated efficacy of non-live probiotic extracts for ruminant productivity.}, issn = {1176-5283}, author = {Jenkins TA and Jenkins V} } @conference {3678, title = {Sheep Dairying in New Zealand - The Kingsmeade Story}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {58-61}, address = {Napier}, abstract = {Kingsmeade has been at the forefront of sheep dairying and innovative cheese-making practises in New Zealand since its inception in 1996. Breeding East Friesian sheep for temperament, type, and productivity has resulted in ewes, including hoggets, capable of achieving lactation lengths in excess of 250 days. A purpose-built factory on their 11-hectare Wairarapa farm currently produces 8.5 tonnes of sheep cheese annually. A further 8.5 tonnes of cow cheese is also produced on-site. Sustainable business practises have been created to ensure minimal wastage and environmental damage. Sales of cheese occur predominantly in the North Island and have been focused on long-term customer relationships by supplying smaller, more exclusive retailers and wholesalers with a unique, artisan product. Further expansion is dependent on acquiring local sheep milk producers. Export is planned with increased cheese production.}, issn = {1176-5283}, author = {King ME and King JE and Powell CB} } @conference {3678, title = {The sire breeding programmes of the Department of Lands and Survey and Landcorp Farming Limited}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {124-132}, address = {Napier}, abstract = {Over 44 years to 2011, the Department of Lands and Survey (Lands and Survey) and its successor Landcorp Farming Ltd (Landcorp), operated sire breeding programmes to service the large populations of females run on the many commercial farms operating under these two respective institutions. Following the establishment of the first breeding programme in 1967 (the Waihora Romney Programme), a total of 19 sheep, six beef cattle, 15 deer, and four goat programmes were established at one time or another. When Landcorp was formed in 1987, the breeding programmes were regarded as an integral part of a new coordinated production system. Breeding programmes that promised a better commercial fit for Landcorp replaced older programmes that did not. By 2011, there were five sheep, four beef cattle and five deer herds involved as either maternal- or terminal-sire breeding programmes, all of which have shown positive rates of genetic improvement and sire rankings that are at the forefront of their respective breeding industry sires. As the first animal breeding scientist appointed by the Department of Lands and Survey in 1982, it has been a privilege to have technically managed the breeding programmes, and the development of new selection criteria, database facilities and measurement techniques. This {\textquotedblleft}legend{\textquotedblright} of the Lands and Survey and Landcorp breeding programmes is a documentation of an internationally unique large-animal breeding resource.}, issn = {1176-5283}, author = {Nicoll GB} } @conference {3678, title = {Strategies to grow the value of New Zealand{\textquoteright}s fine-wool sheep industry}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {191-195}, address = {Napier}, abstract = {The New Zealand Merino Company Limited is leading a programme to create new opportunities and value for New Zealand{\textquoteright}s sheep industry by transitioning growers to finer-wool genotypes and enhancing productivity on current and future fine-wool farms. This paper describes the approaches being undertaken to effect these changes and in doing so grow the value of the fine-wool sheep industry of New Zealand. A strategy has been developed that is focussed on changing the knowledge, attitude, skills and aspirations of producers and their key influencers. The strategy has a range of activities that can be grouped into the broad areas of development, awareness, recruitment and engagement. Importantly the on-farm strategy is matched with significant investment in careful product differentiation and improvement of the flow of information and value through the supply chain.}, issn = {1176-5283}, author = {Ferguson MB and Rutherford S and Hamilton N and Hargadon M and Trompf JP} } @conference {3678, title = {Summer lamb production and grazing management of pure swards of plantain (Plantago lanceolata)}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {94-101}, address = {Napier}, abstract = {Plantain is a productive and persistent pasture species known for its capacity to feed livestock over summer, but there has been limited research published on grazing management and lamb production from Tonic plantain in summer without irrigation. Farmlet scale (individual plots ranged from 0.44 {\textendash} 0.75 ha over the three years), randomised and replicated experiments, with grazing lambs on pure swards of Tonic plantain were undertaken over three summers. The treatments were sward height at pre- and post-grazing and stocking rate. Study one was in a wet summer and the plantain was not water-stressed, whereas in study two, it was mainly dry and the plantain was regularly under stress, and in study three, the summer rainfall was erratic, resulting in a period of water stress at the beginning of the experiment. The average daily weight gains (ADG) of the lambs ranged from 81 to 219 g/day across the three studies. The highest ADGs were when soil moisture was not limiting plantain growth and post-grazing sward height was greater than 5 cm (approximately 1500 kg DM/ha). The crude protein concentration of plantain was low (156 -175 g/kg DM) when plants were water stressed and high (236 g/kg DM) when rainfall was adequate. It was concluded ADG of lambs grazing Tonic plantain in summer was greatest when pre- and post-grazing sward heights were 8 and 5 cm, respectively (2000 and 1500 kg DM/ha herbage mass) and the plantain was not water stressed. It is recommended that Tonic plantain be sown with pasture legumes to increase its feeding value and crude protein concentration.}, issn = {1176-5283}, author = {Kemp PD and Kenyon PR and Morris ST and Johnston T and Appleton H and Best HK} } @conference {3678, title = {Supply and demand for lactose in the New Zealand dairy industry}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {215-219}, address = {Napier}, abstract = {Global milk product demand has been rapidly growing in the past decade, which is reflected in an increased demand for milk powders. The New Zealand dairy industry is capitalising on this by shifting its product portfolio towards milk powders. However, current international product specifications in combination with New Zealand milk composition and an industry objective to maximise farm profitability makes the industry deficient in milk lactose. This study aimed to determine how lactose deficit or surplus is influenced by changes in the product portfolio. In order to quantify this lactose balance, a computer simulation model was used (Moorepark Processing Sector Model). The 2012 New Zealand milk production (19.129 billion litres, milkfat concentration (4.99\%), protein concentration (3.82\%) and lactose concentration (4.70\%, anhydrate)) was used within the analysis. Four manufacturing portfolio scenarios were investigated with different proportions of milk diverted to whole milk powder production (80\%, 60\% (current proportion), 30\% and 10\%). The model simulated the total production of whole milk powder, skim milk powder, casein, whey powder, buttermilk powder, butter and cheese. Whole milk powder production varied from 2,292,000 tonnes for the 80\% scenario to 286,000 tonnes for the 10\% scenario. Lactose mass balance varied from 214,000 tonnes in deficit for the 80\% scenario to 510,000 tonnes in surplus for the 10\% scenario. These analyses indicate that as more whole milk powder is produced, milk from current New Zealand cows results in an increased deficit of milk lactose. The national breeding objective could be adjusted to reflect changes in the future product portfolios to better align the composition of milk with the likely product mix.}, issn = {1176-5283}, author = {Sneddon NW and Lopez-Villalobos N and Hickson RE and Shalloo L and Garrick DJ and Geary U} } @conference {3729, title = {What farmers will need from scientists over the next 20 years under a resource-capped environment}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {254-259}, address = {Napier}, abstract = {Farmers in the Lake Taupo catchment are operating under a Waikato Regional Council consent to farm that limits the amount of nitrogen that can be leached below the root zone. The main driver for nitrogen leaching is stock urine, effectively capping livestock numbers. This challenges current farm business models of intensifying stock numbers in response to rising costs. This paper outlines lessons from on-farm nitrogen-leaching trials carried out by AgResearch and Landcare Research. Farming in the Lake Taupo catchment will only be viable if consumers pay a premium for beef produced in a manner that protects the water quality of Lake Taupo sufficient to offset the increased costs of production. While this has been shown to be practical in the local area it may not apply in other areas of New Zealand or overseas. This raises a series of science priorities to support viable farming. Also discussed are the science needs indicated by the Lake Taupo Protection Trust formed to facilitate the removal of 20\% of nitrogen leaching from farmed land. Currently science has provided no alternative permanent solutions other than removing farms from the catchment}, issn = {1176-5283}, author = {Barton MD} } @conference {89236, title = {Another look at shearing lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {120-125}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

Some farmers believe shearing lambs improves weight gain. On four separate farms, lambs were randomly drafted into two groups in summer, one was shorn while the other was crutched but left unshorn. They were subsequently run as one mob until all were shorn as yearlings in spring. Corriedale lambs (n = 100 x 2 years and 50 per treatment in a third year) were used on one farm, Halfbred lambs (n = 100 per treatment x 1 year) on another farm and two farms used Merino lambs (n = 50 per treatment on each farm x 1 year). Averaged across three consecutive years, the Corriedales shorn as lambs were 2.8 kg heavier as yearlings (P \<0.001) and grew 629g more wool (P \<0.001), which could be profitable. Halfbred yearlings shorn as lambs were 0.85 kg heavier (P = 0.041) and although not significant, grew more wool (120 g). Shorn Merino lambs produced 140 g more wool on one farm (P = 0.019) only, with no significant live weight differences between shearing treatments on either farm. International literature suggests the decision to shear lambs should be based on availability of feed, cost of shearing, time of year, temperature and the riskof flystrike, grass seed damage or adverse weather.

}, issn = {1176-5283}, author = {Scobie DR and Marshall AJ and van Koten C} } @conference {89244, title = {Association of the KRT33A (formerly KRT1.2) gene with live-weight and wool characteristics in yearing Perendale sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {158-164}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

DNA samples from 691 mixed-sex Perendale sheep, born between 1998 and 2001, were typed for variation in the KRT33A gene using polymerasechain reaction - single-strand conformational polymorphism. The sheep were the progeny of two linesselected for either decreased (L), or increased (H) core bulk at yearling shearing, crosses between the lines and back-crosses. Five variants (A{\textendash}E) of KRT33Awere identified with a frequency of 0.07, 0.04, 0.07, 0.35 and 0.47, respectively. The proportion of Adecreased and Bincreased, with a progressive increase incrimp frequency, fibre curvature and core bulk and a progressive decrease infleece weight, staple length and washing yield with each step-wise increase in the proportion of genes derived fromthe H line. An effect of the presence of Aon the measured wool characteristics was found, but was less than the effect with direct selection for core bulk. There was no consistent effect on body growth. While none of the variants of KRT33Awere strongly predictive of variation in core bulk, other genes on Chromosome 11 may be implicated in the differential expression of characteristics associated withcore bulk.

}, issn = {1176-5283}, author = {Sumner RMW and Forrest RHJ and Zhou H and Henderson HV and Hickford JGH} } @conference {89243, title = {Association of variation in the ovine ADRB3 gene with weaning weight and post-weaning growth in New Zealand Suffolk sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {155-157}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

β3-adrenergic receptors (ADRB3s) are mediators of the lipolytic and thermogenic effects of catecholamine levels in brown and white adipose tissue. Studies have linked variation within the β3-adrenergic receptor gene (ADRB3) to metabolic disease and obesity in humans (NCBI OMIM No. 109691), variation in loin eye muscle area in pigs (Hirose et al. 2009) and with dairy form in cattle (Connor et al. 2006).

}, issn = {1176-5283}, author = {Yang G and Forrest RHJ and Zhou H and Fang Q and Hickford JGH} } @conference {89251, title = {Behaviour of New Zealand pasture-based cows offered access to free stalls fitted with sand or water beds, compared with cows at pasture}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {186-188}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

New Zealand dairy cows have typically been \ grazed on pasture all year round, however intensification of milk production systems has led to increased nitrogen loss into the environment (de Klein \& Ledgard 2001; Luo et al. 2007). Limiting the amount of time that cows have access to pasture, particulalry during inclement weather, by the use of feed pads or cow housing for parts of the season or day (de Klein 2001), can reduce nitrogen loss into waterways (Christensen et al. 2012). This approch is particularly important in protecting the soil and pasture from treading damage (Arnold 2009) and can allow non-lactating cows to be retained on the dairy unit over the winter or animals to be sheltered from excessive rain, cold and sunshine. Unfortunately, many New Zealand dairy farmers and the majority of cows have little or no experience of cow housing.

This experiment was completed to assess the acceptance and use of differing free stall bed types by adult dairy cows, with no previous experience of housing, and to compare this with cows kept at pasture. The evening and nightly, daytime grazing and overall daily behaviour patterns of these cows are reported and discussed in this brief comunication.

}, issn = {1176-5283}, author = {Lau J and Margerison JK and Hedley MJ and Horne DJ and Hanly JA and Powell N and Shilton AN} } @conference {89253, title = {Can milk urea nitrogen differentiate nitrogen use efficiency of lactating cow groups raised on New Zealand pasture}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {199-201}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

Improving nitrogen use efficiency (NUE) (g of milk nitrogen output/g of nitrogen intake) of dairy cows helps to maximise profitability and minimise nitrogen losses on farm. However, the traditional nitrogen balance technique used indoors to measure dry matter intake (DMI) and NUE is labour intensive, costly and unsuited to pasture-based grazing systems. In The Netherlands, milk urea nitrogen (MUN) has been used as a non-invasive and easy-to-conduct test to differentiate NUE of dairy cow groups (Kuipers et al. 1999). Generally, higher values of MUN are associated with a lower NUE. However, the usefulness of MUN in New Zealand pasture-based grazing systems is uncertain for numerous reasons. Firstly, MUN excretion reaches a maximum when dietary crude protein (CP) exceeds 20\% of feed dry matter (DM), reducing the sensitivity of MUN to differentiate NUE in high dietary CP systems (Reynolds \& Kristensen 2008). Secondly, water intake has been identified as one of the factors influencing the concentration of MUN, but it is not normally quantified in grazing systems (De Campeneere et al. 2006). Lastly, when individual cow samples are used, MUN may be subject to diurnal variation (Cheng et al. 2010).

}, issn = {1176-5283}, author = {Aizimu W and Hodge S and Edwards GR and Dewhurst RJ and Cheng L} } @conference {89241, title = {Can weighing multiple times increase the accuracy of live weight recording?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {146-148}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

The recording of live weight in livestock enterprises is fundamental for breeding and production, the ease of which has been greatly improved with the advent of automated weighing and recording platforms. However, the extent to which significant advances within a livestock enterprise can be made with the utilization of live weight data depends on the validity of the indicated weights which can be influenced by measurement error from a number of sources (Hughes 1976). Thus, the use of scales only provides an estimate of an animal{\textquoteright}s true live weight. Despite the importance of live weight, there is a distinct paucity of published data surrounding the variation in live weight estimates and weighing protocols that may be used to reduce this variation.

}, issn = {1176-5283}, author = {Galwey JM and Logan CM and Greer AW} } @conference {89220, title = {The changing nature of farm system research}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {54-64}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

A personal review of the contribution of farm systems research to New Zealand pastoral agriculture. Case studies have been selected from the author{\textquoteright}s experience in sheep, dairy beef and dairy cow research over the past 40 years. These are used to emphasise the importance of progress in agricultural science and of wider societal concerns. The change in emphasis over time for farm systems research, from animal production per se, to production and profit, and now to production, profit and environmental protection is highlighted. Examples are also given of the value of thinking in a systems context in order to maximise the value of investment in basic and applied agricultural research.

}, issn = {1176-5283}, author = {Clark DA} } @conference {89242, title = {Comparing herd selection strategies fo A2 beta-casein}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {149-154}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

Herd conversion strategies for A2 beta-casein were investigated within an inter-temporal simulation model with annual time-steps comprising three sub-herds based on allele status (A1A1, A1A2, and A2A2). Cows that are homozygous for the A2 allele of the beta-casein gene are known as A2 cows (A2A2), and produce milk known commercially as {\textquoteleft}A2 milk{\textquoteright}. The simplest herd conversion process is to use semen from A2A2 bulls. However, the conversionfunction is curvilinear and asymptotic and this strategy by itself cannot achieve herd purity. Conversion rates can be increased markedly through genotyping of calves and/or cows. This is necessary for completion of the conversion process. Mating of yearlings with A2 semen can have considerable impact, particularly in association with increased replacement rates. Combining these strategies can lead to pure A2A2 herds within 5 to 8 years, depending on initial herd structure. Use of sex-selected semen can further reduce the conversion period. There is potential for reduced cow herd gain in breeding worth as a result of non-use of elite bulls that are not A2A2. For example, a loss of 20 breeding worth units in the bull team would result in ten years being required to achieve breeding worth gains otherwise achievable in nine years.

}, issn = {1176-5283}, author = {Mencarini IR and Woodford KB and Old KM} } @conference {89224, title = {A comparison of aspects of the reproductive success of ewe lambs and mixed age ewes joined over the same period}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {76-78}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

Ewe lamb breeding at 7 to 8 months of age in extensive production systems, such as utilised in New Zealand, has a number of advantages including higher net profit from lamb production, improved utilisation of spring herbage, improved ewe lifetime performance and improved reproductive rate throughout the flock (Kenyon et al. 2012). However, in comparison to mature ewes there are limitations to ewe lamb breeding which include a lower lambing percentage, lower lamb birth weight\  and lower lamb survival (Annett \& Carson 2006; Kenyon 2012).

}, issn = {1176-5283}, author = {Corner RA and Blair HT and Morris ST and Kenyon PR} } @conference {89222, title = {Comparison of castrate and entire ram-lambs for meat quality and skatole in the fat}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {68-70}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

Ram lambs are favoured in sheep production systems for their faster growth rates compared to ewe, castrate and cryptorchid lambs (Fisher et al.2010). The meat from ram lambs has been associated with poorer tenderness and colour characteristics when compared to the meat from ewe lambs of the same breed (Johnson et al. 2005; Craigie et al. 2012) but, the results across studies are inconsistent with some studies reporting no difference in meat quality between the sexes (Navajas et al. 2008, Kerslake et al. 2012). In a study by Rousset-Akrim et al. (1997), seven-month old male lambs had undesirable meat quality characteristics compared to three-month old male lambs suggesting that age of the lambs and the attainment of puberty are likely to influence the meat quality when comparing between sex classes.

}, issn = {1176-5283}, author = {Schreurs NM} } @conference {89225, title = {Comparison of mating start date definitions for New Zealand dairy farms}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {79-82}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

If the mating start date (MSD) is incorrectly established through database monitoring, then several reproductive measures will also be incorrect in a seasonal calving dairy herd. The definition currently used by the InCalf Fertility Focus report is the first day withartificial breeding (AB) record(s) within a sequence of four of seven days with artificial breeding (AB) records (Method A). The objective was to compare this with alternative definitions to reduce the occasional incidence of incorrect MSD that have been encountered in these reports. The alternative definitions testedwere two consecutive and four out of seven days (Method B), one percent (Method C) and three consecutive days (Method D). The National Dairy Database was used to test these alternate definitions. Among 963 herds with less than 150 cows, the current definition of MSD was the most appropriate. Among 7,004 herds with greater than or equal to 150 cows, visual assessment indicated that a new definition was more accurate. This was that MSD be set as the first of two consecutive days when followed with four of the next seven days having recorded AB matings.

}, issn = {1176-5283}, author = {Creagh FE and Sanders K and McNaughton LR} } @conference {89257, title = {Cows becoming clinically lame differ in changes in behaviour and physiology compared to cows that do not become clinically lame}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {5-10}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

The hypothesis that sensors can detect changes in behaviours and physiologiesassociated with cows becoming clinically lame was tested by comparing trends of sensor data from lame cows with non-lame cows. Sensor data included data from live weighing scales, pedometers (average steps per hour) and milk meters collected between November 2010 and June 2012 on five Waikato dairy farms. Farmers were trained in detecting and diagnosing lame cows. For each lameness event (n = 318 events affecting 292 cows) a time period of 14 days prior to the day ofdetection was randomly matched by farm and date to 10 non-lame cows. In this period, lame cows decreased in weight, steps taken per hour, milk yield in the first two minutes of milking, total milk yield, and milking duration. Lame cows also entered the milking platform later. In comparison, non-lame cows had no change in sensor data trends. These differences (P \<0.05) in sensor data trends imply potential value of sensor data in detecting lameness automatically. Large variations in sensor data values between and within lame and non-lame cows indicated that future research should focus on combinations of variables that show the best potential to detect lameness automatically.

}, issn = {1176-5283}, author = {Kamphuis C and Burke JK and Jago JG} } @conference {89272, title = {A cross-sectional survey of New Zealand sport horse stud farms}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {71-75}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

An online survey was sent to 74 sport horse owners. With a response rate of 45\% (33/74) data were available from 33 owners of 74 sport horse stallions. Most stallion owners were female (29/33; 88\%), aged between 35 and54 years (25/33; 76\%), and had equine occupations (17/33; 52\%). Most sport horse stud farms were not operated as the primary income source for the owner (27/33; 82\%). Farms had a median of 2 (Interquartile range (IQR) 1{\textendash}3) stallions and a median of5 (IQR 2{\textendash}9) mares. There were four larger farms standing stallions that also provided frozen semen from stallions resident outside of New Zealand. Most stallions were privately owned (69/75; 92\%) and 47\% (35/74) of stallions originated from overseas. Half the stallions had their own performance record (36/75; 49\%). Natural service was offered for 64\% (47/74) of the stallions, 81\% (60/74) of stallions were available via artifical insemination with fresh or cooled semen, and 37\% (27/74) were available via artifical insemination with frozen semen. The number of mares covered by the stallions per season was heavily left skewed with a median of 5 (IQR 1{\textendash}8). There were a small group of active sires (n = 7) that covered larger books of mares with a median of 42 (IQR 22{\textendash}50).

}, issn = {1176-5283}, author = {George HEA and Bolwell CF and Rogers CW and Gee EK} } @conference {89234, title = {Development of ultrasound methodology to measure cow udder cistern storage capacity in the New Zealand pasture-fed context}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {114-116}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

Studies have demonstrated that, for a given amount of secretory tissue, cows with a proportionally larger cistern produce more milk and are more resistant to the inhibitory effects on milk synthesis of longer milking intervals (Knight \& Dewhurst 1994; Stelwagen \& Knight 1997; Davis et al. 1998). This may be because they can store more milk before milk accumulation begins to inhibit further milk synthesis. Ayadi et al. (2003) demonstrated in a feedlot situation that cisternal volumes can be measured non-invasively using ultrasound technology. Dairy systems based on pasture, such as those in New Zealand, exhibit different challenges to the production of useful data using this technology compared to feed lot systems and the confounding effect of the variability in milking order and the subsequent variations of the intervals between subsequent milking (Molenaar et al. 2012).

}, issn = {1176-5283}, author = {Molenaar A and Leath SR and Caja G and Henderson HV and Cameron C and Challies M and Taukiri K and Chikazhe T and Kaumoana S and Lannou B and Dorleac A and Guy A and Gavin C and Singh K} } @conference {89259, title = {Does Production Worth and Breeding Worth reflect cow profitability?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {17-20}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

Production worth (PW) is an economic index estimating the efficiency that a cow converts feed into farm profit. Breeding worth (BW) is another economic index that estimates a cow{\textquoteright}s or sire{\textquoteright}s ability to breed profitable replacements. This study evaluates how well PW and BW are correlated with net income (NI) per 4.5 tonnes (t) of dry matter (DM) consumed on a pasture based New Zealand dairy farm. During the 2009/10 season at Massey Number 4 Dairy Farm, cow milk yield and composition were determined at monthly herd tests, and live weight data was automatically collected twice daily using a walk-over-weigh system. The results show that this herd is achieving a genetic gain of $6.74 BW per year. Correlations of 0.52 and 0.31 (P \<0.001) were found between NI per 4.5 t DM and PW and BW, respectively. The NI per 4.5 t DM was higher in cows between 3- to 9-years-old than first lactation cows. The NI per 4.5 t DM was also strongly correlated with the milk, fat and protein yields (P \<0.001). This study confirms that PW, rather than BW, better reflects the genetic capability of a cow to convert feed into farm profit.

}, issn = {1176-5283}, author = {Clark BJ and Garcia-Muniz JG and Black PJ and Lopez-Villalobos N} } @conference {89265, title = {Effect of dam size and nutrition during pregnancy on fetal testicular development in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {41-44}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

In male sheep, testicular development is almost complete at birth. Testicular cells start to differentiate as early as Day (D) 27 of gestation followed by steroidogenesis and the activation of associated enzyme systems (Rhind 2004). Sertoli cells are present at around D34 and replication continues postnatally (Hochereau-de Reviers et\  al. 1987). Seminiferous cords that will develop into tubules appear between D35 and D40 (Sweeney et al. 1997; Rhind et al. 2001). By D70 the rete testis is organised in the centre of testis (Sweeney et al. 1997) and between D35 and D85 the GnRH neuronal system develops in the hypothalamus (Caldani et al. 1995). Testicular gonocytes are typically observed between birth and 25 days after birth, and then progressively differentiate into spermatogonia up to 70 days after birth (Sharpe et al. 2003).

}, issn = {1176-5283}, author = {Asmad K and Kenyon PR and Parkinson TJ and Pain SJ and Lopez-Villalobos N and Blair HT} } @conference {89221, title = {Effect of different herbage mixes on lamb meat quality}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {65-67}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

In New Zealand there is increasing use of alternative forage species for finishing lambs. The alternative forages have a higher feeding value as a consequence of the dry matter yield and chemical composition providing for greater intakes and a higher nutritive value (Kemp et al. 2010). Each forage species is unique in its nutrient composition and may provide an advantage for animal production at different times of the year (de Ruiter et al. 2007). To take advantage of the unique attributes of individual forage species, herbage mixes have been proposed to further boost lamb growth.

}, issn = {1176-5283}, author = {Schreurs NM and Kenyon PR and Morris ST and Blair HT and Somasiri SC and Kemp PD} } @conference {89237, title = {The effect of ewe prelamb body condition on triplet lamb performance in a commercial flock}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {126-130}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

Triplet-bearing ewes (n = 999) were identified at pregnancy scanning (PS) and randomly assigned to two pasture feeding treatments through to lamb weaning, FeedPlus (FP) and Control (C). FeedPlus ewes were fed according to theoretical requirements based on live weight and a fetal number of three while C ewes were fed as for twinning ewes. Ewe body condition score (BCS) was similar for FP and C ewes at PS (BCS 3). FP ewes had higher BCS than C ewes at set-stocking one month before the mean lambing date (PL, BCS 2.9 {\textpm} 0.1 versus 2.6 {\textpm} 0.1, P \<0.001). Every unit increase in BCS at PS improved litter survival to weaning by 0.33 {\textpm} 0.17 of a lamb. An increase of BCS at set-stocking improved litter survival to weaning by 0.45 {\textpm} 0.18 of a lamb (P \<0.05). Litter weight increased with increasing BCS PL (β= 1.2 {\textpm} 0.5 kg/unit BCS, P \<0.05). Low BCS ewes (BCS <=2.5) at PS weaned 3.5 kg less lamb than medium BCS ewes at PS (BCS >=3) (82.4 {\textpm} 1.1 kg versus 85.9 {\textpm} 1.4 kg, P \<0.05) when rearing triplets. Pre-lamb BCS had a positive effect on lamb weaning weight (β= 1.3 {\textpm} 0.6 kg/unit BCS, P \<0.05) and on lamb growth rates from birth to weaning (β= 13.5 {\textpm} 6.0 g/day per unit increase in PL BCS, P \<0.05). The study highlighted the importance of ewe body condition score at PS and PL on triplet ewe performance.

}, issn = {1176-5283}, author = {Everett-Hincks JM and Stevens DR and Rendel JM and Smith TR and Smith PJ} } @conference {89232, title = {Effect of heifer live weight on calving pattern and milk production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {103-107}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

Many heifers on New Zealand dairy farms fail to reach their target live weight. This failure leads to lost milk production and poorer reproductive performance. This study investigated effects of breed and region on heifer live weight and also effects of pre-calving heifer live weight (18{\textendash}21 months) on milk production. Less Friesian heifers reached their target live weight than Jerseys, or Crossbreds (85.3 versus 89.3 versus 88.1\%; P \<0.001). Heifers born in Otago (91.9\%) and Taranaki (91.8\%) were the closest to achieving their target live weight, whilst those born on the West Coast (85.6\%) and Northland (86.0\%) had the greatest number of heifers not reaching their target. Heifers that had only one calving recorded on the database were a significantly lower percentage of target live weight than those heifers that had two calvings recorded (83.5\% versus 87.1\%; P \<0.001). In heifers with a live weight record between 18 and 21 months of age, every 1\% increase in the percentage of target live weight attainedwas associated with an increase in milk volume of 23 {\textpm} 0.6 litres in the first lactation and 24 {\textpm} 0.9 litres inthe second lactation. Further work is required on the economics of feeding heifers to achieve their target live weight.

}, issn = {1176-5283}, author = {McNaughton LR and Lopdell T} } @conference {89266, title = {The effect of milking frequency in early lactation on gene expression in the bovine mammary gland}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {45-47}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

In ruminants, altered milking frequency influences milk production due to either an increase in the number of secretory mammary epithelial cells and/or the activity of these cells (Stelwagen 2001). Microarray studies examining the response of mammary epithelial cells to either increased (Connor et al. 2008) or decreased (Littlejohn et al. 2010) milking frequency, reportedaltered gene expression in several regulatory pathways. These changes would appear to be locally regulated within the mammary gland, as milk production is different in different glands within the same udder depending on the milking frequency of individual glands (Stelwagen 2001). Therefore, the udder lends itself well as a model system to study the effect of different milking frequencies by comparing the response in adjacent udder halves (Murney et al. 2012).

}, issn = {1176-5283}, author = {MacLean PH and Stelwagen K and Maqbool N and Oden K and Murney R and Couldrey C and Singh K} } @conference {89255, title = {Effect of post grazing residual and concentrate feeding on milk production in early lactation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {205-210}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

Two strategies to increase nutrient supply to early lactation dairy cows were compared and the cumulative effects on pasture quality and milk production were investigated. In a farmlet experiment the effect of feeding pasture only, or pasture plus concentrate (4kg/cow/day) at low (3.5 cm) or high (5.0 cm) post-grazing pasture residual (PGPR) was determined using a 2 x 2 factorial combination. Milk production for four groups of eight Friesian x Jersey dairy cows was measured within three consecutive grazing rotations during the first 12 weeks of lactation. PGPR for the low and high treatments remained constant throughout the 12 week period at 3.7 and 4.5 cm respectively. Mean milk solids production in the first, second and third rotation were 1.99 {\textpm} 0.12, 2.14 {\textpm} 0.10 and 2.01 {\textpm} 0.09 kg MS/cow/day respectively. Increasing PGPR from 3.7 to 4.5 cm did not affect pasture quality, milk production or milk composition. Concentrate feeding increased milk solids yield by 0.30 kg (P \< 0.05) in the third rotation. Concentrate feeding also increased milk protein yield by 68 g (P \<0.05), 104 g (P \<0.05) and 167 g (P \<0.001) in the first, second and third rotation respectively. When pasture quality is not altered by PGPR, feeding a concentrate is more effective at increasing nutrient supply than raising grazing height.

}, issn = {1176-5283}, author = {Bryant RH and Harkin C and Vazathara T and Edwards GR} } @conference {89268, title = {The effect of re-milking following extended non-milking periods on the proliferation and apoptosis of mammary gland epithelial cells in dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {51-53}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

In dairy cows, the increase in milk yield from parturition to peak lactation is attributed to an increase in the secretory activity of mammary epithelial cells (MECs) (Capuco et al. 2001). However, following peak lactation, there is a decline in milk production, which is attributed to the loss of MECs by programmed cell death or apoptosis (Capuco et al. 2001). The role of involution and the factors that regulate it in the bovine mammary gland are not well understood. Previous studies have characterised the process of involution in the bovine mammary gland by determining whether involution is reversible following an extended milk stasis. Involution was fully reversible following seven days of non-milking (Dalley \& Davis 2006), but was only partially reversible following longer non-milking intervals (Noble \& Hurley 1999; Singh et al. 2012).

}, issn = {1176-5283}, author = {Mallah GS and Dobson J and Moon S and Henderson HV and Molenaar A and Guan J and Singh K} } @conference {89258, title = {Efficiency of beef breeding cows that vary in live weight and milking potential}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {11-16}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

Size and milking potential of beef breeding cows affect their productivity and efficiency. This experiment compared the productivity and efficiency of straightbred Angus (AA) (high live weight, low-milk potential), Angus-cross-Holstein Friesian (AF) (high live weight, high-milk potential), Angus-crossKiwicross (AK) (moderate live weight, high-milk potential) and Angus-cross-Jersey (AJ) cows (low live weight, high-milk potential). High-milk lines produced heavier calves at weaning than the low-milkproducing AA. AF and AK cows weaned the heaviest calves at 225 {\textpm} 3 kg and 224 {\textpm} 4 kg respectively. These calves were heavier than those weaned by AJcows (212 {\textpm} 3 kg). All of these three genotypes weaned heavier calves than AA cows (197 {\textpm} 3 kg). In turn, all three high-milk lines had greater weaning efficiency ((weaning weight of calf/weight of cow at calf weaning) x100) than AA cows which had an efficiency of 36.7 {\textpm} 0.7\%. AJ and AK cows were the most efficient at 46.7 {\textpm} 0.7\% and 46.0 {\textpm} 1.0\%, respectively. AJ cows were also more efficient than the AF cows (44.0 {\textpm} 0.8\%). Increased milking potential and decreased live weight of breeding cows increased their efficiency of production.

}, issn = {1176-5283}, author = {Law NL and Hickson RE and Lopez-Villalobos N and Kenyon PR and Morris ST} } @conference {89262, title = {Estimating 24-hour milk,fat and protein yields and somatic cell count for automatically milked cows in pastoral production systems}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {29-32}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

Currently, there are no accepted methods for conducting herd tests on farms using fully automated milking systems in New Zealand. This study used data from the DairyNZ Greenfield pasture-based automatic milking research farm to evaluate six milksampling protocols to estimate daily milk, fat and protein yield and somatic cell count (SCC). Total milk, fat and protein yield, and SCC were estimated using all samples collected within 12, 16, 18, 24 and 36 hours from the start of the herd test and for a single test-day sample and compared with values calculated from a 48-hour gold standard herd test day. The correlation coefficient for milk and protein yields were relatively consistent when the sampling interval was shortened to 12 hours (r = 0.95, r = 0.94 for 12 hour milk yield and 12 hour protein yield). However, for fat yield it reduced from 0.96 for a 36 hour sampling interval to 0.88 for a 12 hour interval. The number of cows without a milking increased from 6.7\% to 27.8\% when the sampling interval decreased from 36 to 12 hour. A 24 hour sampling interval provided high correlations for milk, fat and protein yields, and SCC, with a 48 hour gold standard and minimised the number of missed cows.

}, issn = {1176-5283}, author = {Jago JG and Burke JK} } @conference {89231, title = {Estimation of protein utilization efficiency and metabolisable protein efficiency in lactating cows grouped by breeding worth}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {100-102}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

The efficiency of conversion of feed protein to milk protein (protein use efficiency (PUE)) is important in ruminants as protein is the most valuable component of milk (Ryan et al. 2011). It is also essential to reduce nutrient and resource costs when the efficiency of nutrient use is low (Roberts, 2008). In ruminants, dietary protein has three main routes of metabolism, namely microbial fermentation in the rumen, absorption in the small intestine, and catabolism and excretion of excess digestible protein into faeces and urine nitrogen (Agricultural Research Council 1980). This makes PUE difficult to explain and predict because of the interaction of these pathways. Rumen degradable protein (RDP) and metabolisable protein (MP) are the two main protein pools for milk protein production.

}, issn = {1176-5283}, author = {Wheadon NW and Cheng L and Dewhurst RJ and Edwards GR} } @conference {89248, title = {Evaluation of lambs subjected to a targeted selective treatment anthelmintic regime}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {175-179}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

Targeted selective anthelmintic treatments (TSTs) can identify individuals less reliant on anthelmintic, information from which could be utilised to select lambs based on anthelmintic requirement. However, it is important to first determine if selection based on anthelmintic requirement compromises genetic potential for productive traits. Sheep Improvement Limited (SIL) estimated breeding values (eBVs) for production traits and associated indexes for 214 female lambs and 158 male Coopworth lambs were compared with their requirement for anthelmintic following exposure to a liveweight gain-based TST regime. Mean liveweight gain for both sexes was reduced with increasing anthelmintic requirement (P \<0.001). Favourable increases in eBVs with decreasing anthelmintic requirement wereobserved for fecundity in both sexes (P = 0.003) and for survival in females only (P = 0.03). No effect was observed for eBVs for maternal survival, weaning weight, maternal weaning weight, live weight at eight months of age, and live weight and fleece weight at 12-months of age (P \>0.05 for all). Dual purpose index values for resilience increased with decreasing anthelmintic requirement (P \<0.001) while meat yield index and overall productivity were not affected (P \>0.05 for both). It is concluded that selection of lambs for low anthelmintic requirement can be made with no apparent compromise in the genetic potential for production traits.

}, issn = {1176-5283}, author = {Greer AW and Pettigrew CA and Logan CM} } @conference {89238, title = {Ewe body condition score and the effect on lamb growth rate}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {131-135}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

Data were analysed to investigate the association between ewe body condition score (BCS) and lamb growth rate (LGR). Ewe BCS was assessed on a scale of 1 to 5 pre-lambing (BCSL) and at weaning (BCSW). Change in BCS throughout lamb rearing (BCSChange) was calculated as the difference between BCS at weaning and pre-lamb. The three way interaction between birth rank, BCSL and BCSChange was significant (P \<0.05). When the interaction was examined for birth rank, it was significant between BCSL and BCSChange in singles (P \<0.05) and twins (P \<0.01), but not in triplets. In singles and twins, lambs with the highest LGR were from dams that had high BSCL and negative BCSChange or those with low BCSL and positive BCSChange. Triplets had a similar trend whereby lambs with the highest LGR were from dams with a high BCSL and a negative BCSChange. This study suggests that if farmers manage their ewes to achieve a high BCS at lambing time this is likely to improve lamb growth to weaning. In addition, identifying ewes with a low BCS at lambing and preferentially feeding them to increase BCS during rearing may increase single and twinlamb growth rates.

}, issn = {1176-5283}, author = {Mathias-Davis HC and Shackell GH and Greer GJ and Bryant AL and Everett-Hincks JM} } @conference {89240, title = {Ewe live weight and body condition in mid-to- late-pregnancy does not affect the maximum heat production capacity of its lamb at birth}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {143-145}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

Under pastoral conditions, lambs are often exposed to wind, cold and rain that result in neonatal mortality. Thus any improved thermoregulatory response has the potential to increase lamb survival. Especially in light lambs, there is a strong negative relationship between birth weight and mortality (Everett-Hincks \& Dodds 2008). Birth weight also regulates the lamb{\textquoteright}s thermoregulatory capability (Kerslake et al. 2010). Lamb birth weight is influenced by ewe live weight, ewe bodycondition score and the variation in these parameters (Everett-Hincks \& Dodds 2008; Schreurs et al. 2012). Therefore, ewe live weight and ewe body condition score may influence the thermoregulatory capability of the newborn lamb and its survival to weaning.

}, issn = {1176-5283}, author = {Martin NP and Kenyon PR and Hickson RE and Kerslake JI and Morris ST} } @conference {89245, title = {Genetic parameters of stayablity measures in a dairy goat herd}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {165-167}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

Doe longevity is an important factor in dairy goat farm productivity and sustainability, as the economic and environmental cost of raising replacement breeding animals per unit of milk production has less impact when spread over a longer period of return. Although stayability has been studied in sheep and cattle, there is little information regarding genetic parameters for longevity traits in New Zealand dairy goats.

}, issn = {1176-5283}, author = {Wheeler M and Foote BJ and Foote JF} } @conference {89264, title = {Genome wide DNA methylation patterns and transcription analysis in sheep muscle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {37-40}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

The Carwell phenotype is a desirable inherited muscular hypertrophy of the Longissimus dorsimuscle in Poll Dorset sheep that does not have any detrimental effect on eating quality, fat deposition or detectable meat tenderness. The Carwell haplotype has been localized to a 350kb region on the distal end of OAR18 near the Callipyge locus (Nicoll et al. 1998) containing three known genes. However, in spite of considerable effort in sequencing and resequencing, the causative mutation has not been identified. Although unsuccessful in identifying the causative mutation, these studies have revealed that the Carwell phenotype displays an imprinted inheritance pattern, with increased muscling associated with inheritance from the sire but not the dam.

}, issn = {1176-5283}, author = {Couldrey C and Brauning R and MacLean PH and Henderson HV and McEwan JC} } @conference {89226, title = {High hydrostatic pressure treatment increases cryo-tolerance of in vitro produced bovine embryos}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {83-85}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

Cryo-preservation is a critical tool to manage the logistics of implementing assisted reproductive technologies in practice, which depend upon the availability of synchronised recipient cows for embryo transfer. However, the various cryo-preservation methodologies are noted for compromising the integrity of cells within the embryo, hence reducing subsequent viability. The challenge faced by practitioners in this field isto increase the success rate of producing offspring following embryo cryopreservation.

}, issn = {1176-5283}, author = {Popovic L and Berg DK and Pribensky C and Henderson HV and Wells DN} } @conference {89254, title = {In vitro ruminal fermentation and methane production from maize silage mixed with high or low quality ryegrass}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {202-204}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

Methane is the main greenhouse-gas produced by New Zealand agriculture (Ministry for the Environment 2011). The methane loss from ruminants generally ranges from 4.5\% to 9\% of gross energy intake (Hammond et al. 2009). This indicates there is scope for lowering methane production. Replacing pasture forage with maize silage could decrease methane emission by altering fermentation patterns and by reducing rumen pH or ruminal retention time with the addition of starch to the diet (Beauchemin et al. 2008). However, Waugh et al. (2005) found that methane yield (g/kg DM intake) increased when pasture forage was substituted with up to 35\% maize silage in dairy cows fed at similar intakes. Other literature suggests that methane yield in cattle responds in a quadratic manner when pasture forage is substituted with maize silage or grain (Blaxter \& Wainman 1964; Arndt et al. 2010; Hassanat et al. 2012). This effect is associated with pasture forage quality (Kirkpatrick et al. 1997).

}, issn = {1176-5283}, author = {Jonker A and Pacheco D} } @conference {89235, title = {Insulin response to a glucose tolerance test in 18-month pregnant heifers as a predictor of subsequent survival}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {117-119}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

A decline in dairy cow fertility in the USA and in the UK (Beam \& Butler 1999; Royal et al. 2000) has also been noted in New Zealand. Calving rate, the proportion of cows re-calving within the first 42 days of the subsequent seasonal calving period, in New Zealand decreased from approximately 70\% in 1991 to 60\% in 2004 (Harris et al. 2006). There has been no further deterioration in subsequent years.

}, issn = {1176-5283}, author = {Hutchinson KJ and Davis SR and MacKenzie DDS and Blair HT and McNaughton LR and Sanders K and Spelman RJ} } @conference {89230, title = {A Longitudinal study of production and survivability of carry-over cows in a commercial dairy herd}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {96-99}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

In earlier work, we showed that two cohorts of carry-over cows produced 10\% more milksolids (MS) in the first lactation (2008/09) subsequent to the carry-over (non-lactating) season. Here we present further production data for this cohort through to the fourth post-carry-over lactation, together with production data for two further cohorts through to their second and third post-carry-over lactations respectively, and compare this to production from non-carry-over (annual calving) cows of similar breed and breeding worth (BW) in the same herd. Carry-over cow cohorts produced more MSthrough to and including the third post-carry-over lactation relative to non-carry-over cows. We term this additional production the {\textquoteleft}holiday effect{\textquoteright}. First year MS holiday effects were 57 kg (13\%) and 106 kg (23\%); second year holiday effects were 36 kg (8\%), 48 kg (10\%) and 31 kg (6\%); and third year effects were 48 kg (10\%) and 41 kg (8\%). Aggregate survivability through to the fourth post-carry-over lactations of 83\%, 82\% and 71\% respectively were broadly consistent with national survivability statistics. It is concluded that the bio-economics of carry-over cows are worthy of consideration, particularly for young cows of high BW and PW status which have previously given birth at least once.

}, issn = {1176-5283}, author = {Pangborn MC and Woodford KB} } @conference {89250, title = {Mastitis pathogens isolated from dairy cattle that were managed on conventionally or organically maintained matched farmlets}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {183-185}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

Mastitis is a common disease of dairy cattle causing significant economic loss (Seegers et al. 2003), which has been estimated to cost the New Zealand dairy industry $180 million annually (Malcolm 2006). It has been shown that dairy cattle in the first lactation are particularly susceptible to infections from environmental pathogens, including Streptococcus uberis(Woolford \& Lacy-Hulbert 1996) and that this was the most common environmental pathogen, involved in the development of clinical mastitis of dairy cattle in New Zealand (Pankey et al. 1982, 1996; McDougall,1999). Studies completed in the Waikato region of New Zealand described the pathogens isolated from dairy cattle with clinical mastitis and reported that 27 to 75\% of cases were infected with Streptococcus uberis, whereas 9 to 10\% were Coagulase-negative-staphylococci(CNS), 3 to 5\% were Staphylococcus aureus, 2 to 5\% were coliforms and finally 1.5 to 4 \% were\  Strep.

}, issn = {1176-5283}, author = {Ullah Z and Margerison JK and Simcock DC and Thatcher A and Lopez-Villalobos N} } @conference {89252, title = {Milking reproduction}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {189-198}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

Reproductive function is influenced by metabolic status and is compromised in conditions of negative energy balance. In the recent past, significant advances have been madein our understanding of how the brain regulates appetite and energy expenditure, largely due to the identification of blood borne factors that act on the neurons in the hypothalamus that produce the so-called {\textquoteleft}appetite regulating peptides{\textquoteright}. This review provides an overview of the control of energy balance and the interface between {\textquoteleft}appetite regulating{\textquoteright} systems and gonadotropin releasing hormone secretion and action. This is placed in the context of the lactating dairy cow in an effort to understand what might cause poor reproductive performance. It is apparent that we know significantly more about the relationship between energy balance and reproduction in non-bovine species. This review indicates areas which deserve further attention in the dairy cow.

}, issn = {1176-5283}, author = {Clarke IJ} } @conference {89229, title = {Milksolids production of dairy cows grazing lucerne and perennial ryegrass in spring}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {93-95}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

The potential of New Zealand grazing systems is dependant on the dry matter (DM) yield, nutritive characteristics, and utilisation of pasture. The most common pasture is a mixture of ryegrass and white clover, which is tolerant of a wide range of environments and management (Kemp et al. 1999). However species such as these with shallow root systems and poor growth in high temperatures will have reduced herbage accumulation and quality during dry summer periods (Hoglund \& White 1985). As demand for irrigation has increased to alleviate these problems, it has also raised questions about water allocation impacts on dairy farm production and profit (Thorrold et al. 2004). For Canterbury, which experiences hot, dry summers, lucerne is a potential source of high quality feed due to its active warm season growth and greater water use efficiency (Mills \& Moot 2010).

}, issn = {1176-5283}, author = {Smith G and Bryant RH and Edwards GR} } @conference {89260, title = {Modelling the effect of temporary once-a-day milking durinmg early lactation on dairy farm production and profitability}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {21-25}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

The DairyNZ Whole Farm Model was used to predict the effect of temporary once-a-day (OAD) milking during the calving period on milksolids (MS) production, farm profitability and herd body condition score (BCS) at dry-off. Farms from three regions and three independent seasons were modelled for: wholeseason twice-a-day (TAD) milking of all cows (Control), OAD milking of all cows for eight days immediately post-calving and TAD milking thereafter (Col OAD), OAD milking of the herd for three weeks from the planned start of calving (PSC) and TAD milking thereafter (3 wk OAD), and OAD milking of the herd for six weeks from the PSC and TAD thereafter (6 wk OAD). Model outputs indicated MS production (kg/ha) losses of 2, 1.2 and 3.7\% and profit ($/ha) losses of 6.5, 4.5 and 11.6\% for the Col OAD, 3 wk OAD and 6 wk OAD regimes, respectively. Slight improvements in dry-off BCS were predicted for the OAD milking regimes, comparedwith the control. Milking the herd OAD for three weeks from the PSC may be the prefered strategy to offer labour, lifestyle and animal health benefits with the smallest losses of MS production and farm profit.

}, issn = {1176-5283}, author = {Khaembah EN and Rius AG and Beukes PC and Levy G and Gregorini P and Roche JR and Kay JK and Phyn CVC} } @conference {89277, title = {MRI technology to better understand placental placental function in sheep - A pilot study}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {90-92}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

The placenta is the organ responsible for exchange of nutrients and waste products between the mother and her fetus (Bell \& Ehrhardt 2002). It is therefore the main regulator of fetal growth (Murphy et al. 2006). In sheep, placental exchange of nutrients occurs at sites called placentomes (Ford 2000). Placentomes are comprised of cotyledons on the chorioallantoic membrane which attach to discrete caruncles on the uterine wall (Ford 2000). Ovine placentomes can be classified into four types (A, B, C and D) based on their gross morphological appearance (Vatnick et al. 1991). The distribution of placentome type, and size of individual placentomes can be influenced by many factors.These include nutritional status of the dam, placental blood flow, oxygen availability and altitude (Gardner et al. 2002; Osgerby et al. 2002, 2004; Penninga \& Longo 1998).

}, issn = {1176-5283}, author = {van der Linden DS and Oliver MR and McCoard SA} } @conference {89267, title = {mTOR signalling in lactating bovine mammary gland}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {48-50}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

The mammalian target of rapamycin (mTOR) is a protein kinase that has a well established role in the regulation of a range of cellular functions in response to hormones, growth factors and amino acids (Wang \& Proud 2011). The role of mTOR signalling in the regulation of milk protein synthesis in the mammary gland of ruminants is not well understood. Understanding this mechanism is an important step towards developing intervention strategies on farm, such as the supply of nutrients, to modulate milk protein output.

}, issn = {1176-5283}, author = {McCoard SA and Wards N and Singh K} } @conference {89256, title = {The New Zealand beef cattle industry}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {1-4}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

A quick cursory glance of the past 71 Presidential Addresses reveals they usually take one of three forms. Some have given an overview of the agricultural or animal science research scene with particular reference to funding and in particular the shortfall of funds, others have reviewed the Society{\textquoteright}s activities usually through analysis of membership and papers presented at Annual Conferences and suggested future directions for the Society, while others have made a personal statement about an industry or research area. I have chosen the latter and want to speak today about beef production in New Zealand. Beef production gets little recognition in the mainstream press or by many of our farmer politicians. In fact I would suggest many of our Society members would know little about beef production on our farms.

}, issn = {1176-5283}, author = {Morris ST} } @conference {89246, title = {Quantitative trait loci associated with variation in maximum milk flow rate in Friesian -Jersey cross bred cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {168-170}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

On New Zealand dairy farms, the milking process consumes more than half of the available labour hours (Jago et al. 2010). While some recent research has shown some potential to improve labour efficiency of dairy farms during milking (Jago et al. 2010), the speed of milking is, in large part, dictated by the slowest milking cows in the herd.

}, issn = {1176-5283}, author = {Davis SR and Littlejohn M and Ellison R and Spelman RJ} } @conference {89249, title = {Rapid analysis of moxidectin in plasma}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {180-182}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

Intestinal parasites are a significant impediment to the productivity of grazing livestock in New Zealand (Scott et al. 2008). They are regarded by New Zealand sheep farmers as their most important animal health issue (Lawrence et al. 2007). The New Zealand deer industry estimated that parasites cost as much as 5\% of the total farm revenue (Mackintosh \& Wilson 2003). On most farms controlling parasites in order to minimise their impact on animal performance relies heavily on the use of anthelmintics (Lawrence et al. 2007), but their continued usefulness is threatened by the development of worm populations resistant to these drugs (Waghorn et al. 2006a, 2006b). Studies aimed at developing more sustainable worm management practices will be important for maintaining the future productivity and profitability of many farming operations.

}, issn = {1176-5283}, author = {Hughes DC and Fraser K and Miller CM and Leathwick DM} } @conference {89239, title = {Relative performance of three strains of fine-woolled Merino sheep farmed on Waikato hill country}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {136-142}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

Flocks of Saxon (ex Tokanui Research Station), Merryville (ex Tara Hills Research Station) and Fine Peppin (ex Tokanui Research Station) Merino sheep were established at the Whatawhata Research Centre to investigate their relative productivity under North Island hill country conditions. Production data were collected for five years. The Fine Peppin ewes had a higher reproductive rate (0.1 {\textpm} 0.05 (standard error of difference) lambs weaned/ewe joined) with a higher lamb birth weight (0.37 {\textpm} 0.08 kg), lamb weaning weight (1.9 {\textpm} 0.4 kg) and yearling weight (3.5 {\textpm} 0.6 kg), a higher ewe greasy fleece weight (1.2 {\textpm} 0.1 kg) that was longer (7 {\textpm} 2 mm) and coarser (3.0 {\textpm} 0.2 μm) with a greater coefficient of variation of fibre diameter (2.2 {\textpm} 0.4 \%), lower brightness (-1.3 {\textpm} 0.4 CIE Y units) and more yellow (1.1 {\textpm} 0.2 CIE (Y-Z) units) than the Saxon. The Merryville was intermediate between the other two strains for most characteristics. The yearling fleece of each strain exhibited similar trends to the adult fleece. On the basis of the measured performance, and applying wool and lamb price trends between 2007/08 and 2011/12, the differential returns per ewe of the Fine Peppin would be expected to exceed that of the Saxon by $8.80 with the Merryville being intermediate.

}, issn = {1176-5283}, author = {Sumner RMW and Henderson HV} } @conference {89263, title = {Review of milk payment systems to identify the component value of lactose}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {33-36}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

New Zealand{\textquoteright}s export dairy product mix has shifted towards the production of whole milk powder. This has resulted in a deficit in milk lactose to meet international standardisation requirements for whole milk powder. Currently, the deficit in lactose is filled using imported lactose with an estimated cost of New Zealand dollars 300 million annually. This study compares payment systems from America, Europe, Australia and New Zealand, and outlines possible strategies for payment for lactose to New Zealand dairy farmers. The prominent milk payment system in New Zealand is the {\textquoteleft}A+B-C{\textquoteright} multiple component pricing system, where A and B are the monetary values per kilogram of fat and protein and C is the penalty per litre of milk volume. An alternative payment system that may encourage farmers to increase the supply of lactose could be {\textquoteleft}F+P+L-V{\textquoteright} where F, P and L are the monetary values of fat, protein and lactose respectively and V is the penalty per litre of milk volume. This payment system is currently in operation at one small New Zealand dairy processor. This study has shown that the {\textquoteleft}F+P+L-V{\textquoteright} payment system results in smaller deviation from the true value of the milk for differing breeds, milk compositions and product mixes than the current {\textquoteleft}A+B-C{\textquoteright} system of milk payment.

}, issn = {1176-5283}, author = {Sneddon NW and Lopez-Villalobos N and Hickson RE and Shalloo L} } @conference {89247, title = {Some lessons from using zinc-salt treatments to protect dairy cows against facial eczema}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {171-174}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

A trial at AgResearch Ruakura, evaluating two different methods of administering zinc++(Zn) salts to protect cows from facial eczema, was carried out in lactating dairy cows to study the variation in concentrations of blood Zn++. The treatments were: continuous supply of zinc sulphate (ZnSO4) through water troughs (n = 10 cows), versus daily oral drenching with zinc oxide (ZnO) (n = 10 cows). Responses in daily milk yields, and concentrations of Zn++in blood were recorded twice weekly over four weeks for each cow. The ZnSO4trough treatment took ten days for blood Zn++concentrations to equilibrate, after which the sampling-day average ranged from 20{\textendash}26 μmol/L. Between-cow repeatability was 0.42 {\textpm} 0.15. The daily ZnO treated cows equilibrated after drenching for three days. Average blood Zn++concentrations then ranged from 24{\textendash}29 μmol/L. Between-cow repeatability was 0.44 {\textpm} 0.17. Dailymilk yields did not differ significantly between treatments. Target ranges for blood Zn++concentrations to provide protection against facial eczema in lactating dairy cows of 18{\textendash}34 μmol/L were published 26 years ago. These may need to be re-assessed, with changes in breed composition and increases in milk yield over that time within the national herd.

}, issn = {1176-5283}, author = {Morris CA and Hickey SM} } @conference {89233, title = {Spatial-time correlation between milk urea with milk components and somatic cell score of bulk milk samples from farms supplying milk for cheese and milk powder manufacturing}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {108-113}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

Milk urea nitrogen (MUN) has been used to indicate the dietary protein/energy balance for the dairy cow, and may be negatively associated with the content of valuable milk components for the manufacture of dairy products. The objective of the study was to model the temporal pattern of the correlation between MUN and the percentages of fat (FP), protein (PP), lactose (LP) and total milk solids (MSP), and somatic cell score (SCS) (log2somatic cell count) of bulk milk samples from farms supplying milk for the manufacture of cheese and milk powder. Daily records of milk delivery dates, the composition of bulk milk samples for FP, PP, LP, MSP, SCS and MUN from 28 seasonal supply dairy farms were analysed. The results show there is a negative association between MUN and milk components. The concentration of MUN in milk of New Zealand cows is high compared with that of milk from cows fed a total-mixed-ration, due to the high crude protein content in the pasture fed to dairy cows in New Zealand.

}, issn = {1176-5283}, author = {Garcia-Muniz JG and Lopez-Villalobos N and Burken JL and Sandbrok T and Vazquez-Pelaez CG} } @conference {89227, title = {Uterine expression of oestrogen receptor alpha in Suffolk and Cheviot ewes at Day 19 of pregnancy, following embryo transfer}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {86-89}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

Whilst it is recognised that maternal uterine capacity has a marked influence on offspring birth weight and size (Walton \& Hammond 1938; Allen et al. 2002; Jenkinson et al. 2007, 2012; Sharma et al. 2012), Sharma et al. (2010) demonstrated in reciprocal embryo transfer experiments that the maternal uterine environment exerts an effect on embryonic growth by Day 19 in early gestation, when maternal uterine capacity is not a limiting factor.

}, issn = {1176-5283}, author = {Sequeira M and Pain SJ and Sartore I and Meikle A and Kenyon PR and Blair HT} } @conference {89261, title = {Verification of an automated camera-based system of oestrus detection in dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {26-28}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

Accurate oestrus detection is critical in New Zealand dairy farming, where many farms operate a seasonal farming model and, therefore, rely on a compact calving spread and a short mating period to farm efficiently. Automated oestrus detection systems are available that automatically identify and draft cows in oestrus. There are two types of automatic systems available commercially in New Zealand; activity-based systems that involve pedometers/accelerometers and systems that detect mounting behaviour using a sensor attached to the animal{\textquoteright}s back.

}, issn = {1176-5283}, author = {Hempstalk K and Burke CR and Kamphuis C} } @conference {78999, title = {Are dairy heifers achieving liveweight targets?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {120-122}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {The reproductive performance of the national dairy herd has declined (Harris et al. 2006). Heifer rearing is one of eight "ingredients" for achieving good reproductive performance identified by the InCalf project (Burke et al. 2007). Many New Zealand dairy farmers graze their heifers on a run-off or pay a grazier to grow the heifers, with heifers commonly leaving the dairy farm at weaning, or nine months of age and returning at around 22 months of age.}, issn = {1176-5283}, author = {McNaughton LR and Lopdell TJ} } @conference {79020, title = {Are faecal egg counts approaching their "sell-by" date?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {199-204}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Historically, the primary determinant for the state of parasitism has been the concentration of nematode eggs in the faeces (FEC). This descriptor has a number of limitations that have implications for the development of drug resistance and hamper the identification of resilient livestock. A major fallacy is that FEC can reliably assess the worm burden, the need for anthelmintic and the efficacy of that treatment. FEC is a ratio, eggs per gram of faeces, not a quantity. Not only is the denominator ignored but interpretation of the numerator requires knowledge of nematode species present and female fecundity which can be affected by infra-population dynamics. By definition, a parasite exists at the expense of its host. As such, the consistent ability of resilient animals to maintain performance, despite a high FEC, strongly suggests that FEC does not provide a reliable indicator of the cost of parasitism. This manuscript reviews the factors that affect FEC and argues for a step change in our approach to the control of nematode parasitism in pastoral systems to one focused on individual treatments based on animal performance utilising radio-frequency electronic identification and automated weighing and drafting systems.}, issn = {1176-5283}, author = {Greer AW and Sykes AR} } @conference {78979, title = {Associations of uterine pathology with milk production and effects of treatment with a nonsteroidal anti-inflammatory drug in dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {23-27}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {

Subclinical endometritis (SCE) is a form of uterine pathology characterised by an increased proportion of polymorphonuclear cells (PMN) in the uterus post-calving. Previous studies demonstrated a negative association between SCE and lower milk production, with indications that systemic inflammation underlies this link. Accordingly, the hypothesis tested was that treatment with a non-steroidal antiinflammatory drug (NSAID) would increase milk yield in cows with >= 14\% PMN at Day 14. In this study, >= 14\% PMN in the cytological sample collected at Day 14 postpartum was defined as SCE. To test this hypothesis, 213 dairy cows were paired by calving date and Day 14 PMN\%, then randomly assigned to three doses of a NSAID (Carprofen 1.4 mg/kg, n = 103) between 21 and 31 days postpartum or left as untreated controls (n = 108). The effect of the NSAID treatment on milk production was analysed using mixed models. While the results supported previous evidence of a negative association between SCE and milk production, NSAID had no effect on either PMN \% at Day 42 or milk production (P \> 0.1) in this study. The lack of a NSAID effect was possibly because SCE spontaneously resolved in more than 90\% of the cases

}, issn = {1176-5283}, author = {Priest NV and McLeod KLM and McDougall S and Burke CR and Roche JR and Mitchell M and Greenwood SL} } @conference {79026, title = {Chinook salmon (Oncorhynchus tshawytscha) feed conversion efficiency: evaluation and potential for selection}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {227-230}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Improving performance through selective breeding is a key priority for the New Zealand Chinook salmon (Oncorhynchus tshawytscha) aquaculture industry. The family selective breeding programme operated by The New Zealand King Salmon Company has successfully improved growth and quality after six generations of selection. However, feed conversion efficiency is not currently a direct breeding goal. Research was established to analyse daily feed intake and feed conversion ratio, a measure of feed efficiency, in 160 families over two spawning year classes. Daily feed intake assessment methodology employing digital X-radiography was validated and used to obtain repeated measurements of daily feed intake. Measurements of growth, and feed conversion ratio up to harvest size were also obtained. Genetic parameter estimates for daily feed intake and feed conversion ratio indicated that there are family differences for these traits. As a result the continued measurement of feed conversion ratio in The New Zealand King Salmon families and incorporation of the traits into The New Zealand King Salmon breeding programme is being considered.}, issn = {1176-5283}, author = {Walker SP and Ingram M and J Bailey and Dodds KG and Fisher PJ and Amer PR and Symonds JE} } @conference {79009, title = {A comparative analysis of genetic trends within the New Zealand sheep industry}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {159-162}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Rates of genetic progress made by Dual Purpose and Terminal Sire flocks in the New Zealand sheep industry between 1990 and 2007 have previously been examined (Amer 2009) and showed substantial gains in the rate of progress since the introduction of Sheep Improvement Ltd. (SIL) and SIL-ACE (Advanced Central Evaluation). Key findings from this earlier study showed that the rates of genetic progress doubled following the introduction of SIL, and increased by a further 50\% after the introduction of the Beef + Lamb New Zealand Central Progeny test (CPT), which effectively evaluates the performance of key industry sires, providing the ... continued}, issn = {1176-5283}, author = {Sise JA and Byrne TJ and Jopson NB and Young MJ and Amer PR} } @conference {79000, title = {A comparison of milk fat composition between pasture based cows supplemented with either canola meal or wheat}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {123-128}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Increasing the polyunsaturated fatty acid (PUFA) content of milk has been the focus of much recent research. Milk from pasture based cows has been reported to have a high content of PUFA, which can be further manipulated with the addition of supplements differing in fatty acid composition. This experiment used 980 Holstein-Friesian and Jersey crossbred cows in a split treatment design to determine the effect of canola pulp or wheat supplementation on milk fatty acid composition and milk solid production in a typical large pasture based herd. Principle component analysis was used to determine the most influential factors of change in milk composition. Milk solid production did not differ significantly between treatments (P > 0.05), C10:0, C12:0, C14:0, and C16:0 were very significantly (P < 0.001) decreased by the canola pulp treatment. C18:0 anteiso and conjugated linoleic acid were not significantly affected by treatment. C18:1 c9 and C18:1 t9 were very significantly increased (P < 0.001). C18:1 t11 was significantly increased in the canola pulp treatment (P < 0.03). These results show that canola pulp is a potentially valuable supplement for use in grazing based systems. The equivalent response to supplementation compared to wheat would recommend its use if cost on an ME basis was competitive.}, issn = {1176-5283}, author = {Williams DJ and Gibbs SJ} } @conference {79025, title = {Developing broodstock resources for farmed marine fish}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {222-226}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {he expansion of New Zealand aquaculture will benefit from diversification into new high value finfish such as Yellowtail kingfish (Seriola lalandi) and Hapuku (groper, Polyprion oxygeneios). To ensure success, domesticated selected broodstock need to be established along with systems that can reliably produce high quality gametes and juveniles. Collections of wild Kingfish and Hapuku broodstock were completed by the National Institute of Water and Atmospheric Research from 2000 onwards. Over 100 wild broodstock have since been reared to establish the parental stocks. Wild females of both species are very fecund and millions of eggs have been produced each breeding season. One of the main challenges is to ensure that multiple parents contribute during spawning to create genetically variable, selected offspring (F1). Due to the current reliance on communal group spawning, multiplex microsatellite DNA marker panels were developed to determine the parentage of the resulting F1 progeny. Although F1 from multiple parents have been identified, some broodstock produced a disproportionate number of the progeny. This has highlighted the need to manage parental contribution to the F1, which would otherwise exclude many individuals from contributing to the gene pool. As a result we are developing techniques to control mating and to maximise the number of founding wild parents in the programme.}, issn = {1176-5283}, author = {Symonds JE and Walker SP and Van de Ven I and Marchant A and Irvine G and Pether S and Gublin Y} } @conference {79012, title = {Development of a visual scoring system for ovine pneumonia at the processing plant}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {169-171}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Pneumonia in sheep is a consequence of multiple infectious agents compromising the host{\textquoteright}s immune system, often with the aid of environmental factors. Chronic non-progressive pneumonia (CNP) and acute fibrinous pneumonia (AP) are the main concerns to the New Zealand sheep industry. AP occurs in sheep of all ages and is more common in older lambs during the late summer early autumn period. CNP is often seen in lambs aged between five and ten months of age. Clinical diagnosis is difficult with affected lambs showing few, if any, clinical signs of illness as reviewed by (Alley 2002). Accurate diagnosis requires examination of the lung. ... continued}, issn = {1176-5283}, author = {Baird HJ and Clarke SM and PL Johnson} } @conference {79010, title = {Development of epigenomic analysis in agricultural animals}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {163-165}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Advances made in DNA sequencing technologies over the past 15 years (Zhao \& Grant 2011) have resulted in genome wide selection for production traits becoming a reality. Soon all sequence variations in each individual in closed breeding schemes will be known. What is not currently known is how to rank these variations, especially those that involve changes in gene expression rather than amino acid sequence. In order to continue making genetic progress we will need an understanding of how epigenetics affects gene expression and ultimately phenotype.}, issn = {1176-5283}, author = {Couldrey C and Brauning R and Retzel EF and McEwan JC} } @conference {78990, title = {DNA methylation events in the {\'a}S1-casein-encoding gene associated with involution and re-initiation of lactation in dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {73-75}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {During lactation, prolactin activates STAT5 (Signal Transducer and Activator of Transcription5), which binds to conserved DNA sequence motifs in promoters of milk protein genes to stimulate their expression (Liu et al. 1997). Mammary gland involution induced by termination of milking is characterised by a rapid decrease in milk protein gene expression (Singh et al. 2008). Whereas milk production can be fully restored after seven days of ... continued}, issn = {1176-5283}, author = {Pryor S and Swanson K and Couldrey C and Henderson H and Singh K} } @conference {79004, title = {Does castration status have an effect on the quality of lamb meat?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {144-146}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Consumer demand for leaner lamb meat all-year-round and price incentives to produce heavier carcases means that in New Zealand ram lambs are often being left entire in an attempt to improve lamb growth rates (Fisher et al. 2010). While this offers potential improvements in on-farm returns, there are still perceived concerns in the market place that meat from entire ram lambs of a certain age may be unsatisfactory. Based on the latest scientific evidence (Young et al. 2006; Young et al. 2003) New Zealand processors make no distinction between carcasses from lambs of different genders. However, due to continual perceived concerns from consumers, ... continued}, issn = {1176-5283}, author = {Kerslake JI and Hely FS and Maclennan G and Lindsay S and Behrent MR and Campbell AW} } @conference {78976, title = {Dry matter intake and nitrogen losses of pregnant, non-lactating dairy cows fed kale with a range of supplements in winter}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {8-13}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {

An outdoor winter-feeding study conducted over 14 days using 40 Friesian-Jersey cross dairy cows measured dry matter (DM) intake and nitrogen (N) excretion of cows fed kale with either barley straw (S), whole crop barley silage (WCBS) and Lotus pedunculatus silage (LS) fed with (LS+PEG) or without polyethylene glycol (LS-PEG). Treatment groups did not differ in DM utilisation of kale (80\%) or apparent intake of kale (11.6 kg DM/cow/d). Total daily intake of N was lowest for S, intermediate for WCBS and highest for LS+PEG and LS-PEG (280, 323, 350 and 352 g N/cow/d, respectively). Urinary N excretion was lower (P \< 0.05) on kale diets supplemented with either S or WCBS (202 and 186 g N/cow/d respectively) compared with LS+PEG and LS-PEG (227 and 239 g N/cow/d respectively). Supplement treatment did not affect total faecal N excretion but faecal N\% was higher (P \< 0.05) in LS treatment groups (3.05\% in LS+PEG and 3.28\% in LS-PEG), compared with WCBS (2.74\%) and S (2.43\%). This study indicates that the current commonly used feeding system of kale, supplemented with straw, is a feeding system that has a low urinary N excretion compared with alternatives.

}, issn = {1176-5283}, author = {Miller ME and Bryant RH and Edwards GR} } @conference {79011, title = {Economic values for New Zealand dairy goats}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {166-168}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {A deterministic bio-economic farm model was developed to estimate economic values (EVs) for important milk production traits affecting profitability and to define a breeding objective for New Zealand dairy goats. Costs, revenue, metabolisable energy requirements for maintenance and activity, pregnancy, lactation and growth of replacements were included in the farm model. Three payment systems were investigated; Current scenario: Total milk-solids; Scenario 1: Ratio 1:2 for fat (F) and protein (P) and Scenario 2: ratio 2:1 for F and P. A price of $13.00 per kg milk solids (MS) was assumed to calculate daily revenue per milk-solid component. A penalty of $0.04 per litre of milk was applied in the last two scenarios. Assumed values of 3.7\%, 3.2\%, 4.4\% and 0.7\% for fat, protein, lactose and minerals, respectively, were used to estimate price per kg of F and P in Scenarios 1 and 2. For the Current scenario, the EVs for fat, protein, lactose and volume were $11.64, $12.27, $12.39 and -$0.10, while the estimations in Scenario 1 were $14.49, $31.09, -$0.76 and -$0.14, respectively and in Scenario 2 were $28.92, $14.37, -$0.76 and -$0.14, respectively. The EV for live weight was -$2.16 across scenarios. The EVs estimated can be used to establish breeding objectives for New Zealand dairy goats.}, issn = {1176-5283}, author = {Solis-ramirez J and Lopez-Villalobos N and Blair HT} } @conference {78988, title = {The effect of milking frequency in early lactation on milk yield and milk protein gene expression in the bovine mammary gland}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {67-69}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {

In dairy cows, increased milking frequency (MF) has a positive effect on daily milk yield (MY), providing dietary energy intake is sufficient to maintain the increase in production (Phillips et al. 1980). Short-term increases in MF during early lactation may have both an acute effect and a carry-over effect on MY once the animals have returned to less frequent milking (Hale et al. 2003). The critical period for increased MF to generate a carry-over effect on MY is within the first three weeks of lactation and may only need to be applied for as little as 14 days ... continued

}, issn = {1176-5283}, author = {Murney R and Stelwagen K and Singh K} } @conference {78989, title = {The effect of re-milking following extended non-milking periods on lactation in dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {70-72}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {In dairy cows, the cessation of milk removal for extended periods, such as drying-off, initiates the process of mammary gland involution. This results in a decline of mammary secretion and changes in secretion composition. Morphological changes in the mammary gland occur within the first week of non-milking, with extensive re-modelling by the third or fourth week. However, many alveolar structures are retained (Hurley 1989). Thus, involution may be reversible following extended non-milking periods (Noble \& Hurley 1999). Milk yield is fully restored ... continued}, issn = {1176-5283}, author = {Singh K and Swanson K and Henderson HV and Stelwagen K} } @conference {79027, title = {Effect of resolving a sub-clinical uterine infection on plasma and follicular fluid steroid concentrations in early lactation dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {231-235}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Sub-clinical endometritis (scEndo) in early lactation affects ovarian follicle dynamics, delays a return to cyclicity, with changes in plasma and follicular fluid (FF) amino acid concentrations around the time of rebreeding. This study examined the effect of resolving scEndo in early lactation on plasma and FF oestrogen, progestagen, androgen and corticosteroid concentrations at the time of rebreeding in 46 dairy cattle. On D42 postpartum, cows were classified as having scEndo, clean or having resolved scEndo cased on uterine cytology on D21 of > 18\% polymorphonuclear (PMN) cells amongst uterine nucleated cells. On D42 and D63 follicular and plasma samples were collected and steroid concentrations analysed. On D21 and D42, 35\% and 7\% of cows respectively were classified as having scEndo, with 81\% of scEndo cows having self-resolved the infection by D42. In those cows that resolved scEndo, none of the plasma or FF steroid concentrations changed between D42 and D63, except for plasma progesterone (P = 0.08). Using a low (4\%PMN) threshold to classify scEndo did not identify any significant changes in steroid concentrations. In contrast to previously described changes in plasma and FF amino acid concentrations, there were no significant effects on steroid concentrations when cows self-resolved a sub-clinical uterine infection.}, issn = {1176-5283}, author = {Lopdell TJ and Berg MC and Green MP and Back PJ} } @conference {79021, title = {Effect of the maternal environment on fetal growth at mid-gestation in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {205-209}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Our group has previously shown that maternal size can affect embryonic development by Day 19 of gestation and lamb birth weight. This study set out to investigate the effect of the maternal uterine environment on fetal growth at mid-gestation. Pure-breed single embryos were transferred within and reciprocally between large (Suffolk: S) and small (Cheviot: C) breeds of ewes to establish four maternal environments; SinS, SinC, CinS and CinC. On Day 90 of gestation, 37 single-bearing recipient ewes (10 CinC, 7 SinC, 10 CinS and 10 SinS) were euthanased. Fetal body weight, fetal body dimensions and fetal organ weights, and placentome number and total weight were measured. Body weight was significantly (P < 0.001) smaller in Cheviot compared to Suffolk fetuses. However, Cheviot fetuses had heavier (P < 0.05) kidneys and liver than Suffolk fetuses. SinC fetuses had heavier (P < 0.05) pancreas than those from all other pregnancy groups. CinS fetuses tended to have longer (P < 0.10) fore- and hind-leg lengths than CinC fetuses. There were no differences (P > 0.05) in placental parameters between the pregnancy groups. The maternal uterine environment had no major effect on fetal weight, fetal dimensions and fetal organ mass at mid-gestation.}, issn = {1176-5283}, author = {Jenkinson CMC and Sharma RK and Kenyon PR and Blair HT} } @conference {79002, title = {The effect of training to the milking parlour on the behavioural response to milking and milk production in first lactation heifers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {134-138}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {The objective of this study was to investigate the effect of training on the behaviour and milk production of heifers. Approximately three weeks prior to calving, heifers from two commercial farms were either trained over three days to the rotary milking parlour (TRAIN: n = 104) or left undisturbed in the paddock (CON: n = 113). Behavioural observations of heifers during the milking process were recorded over the first week of lactation. Behaviours recorded included the performance of flinching, stepping and/or kicking and the duration to attach the cluster. Individual heifer milk yields, milking durations, average milking flow rates and reattachment count of the cluster were recorded daily for the first six weeks of lactation. During the milking process, TRAIN heifers performed more leg lifts, a greater number of backward kicks and the number of times the milking cluster had to be reattached during each milking was greater than CON heifers. There was no difference in milk production measures between TRAIN and CON heifers. These results suggest that the method of training used in this study was not adequate to reduce the behavioural response of heifers to milking during the first week of lactation.}, issn = {1176-5283}, author = {Dowling SK and Sutherland MA} } @conference {78985, title = {Effects of maternal nutrition during pregnancy on the growth and reproductive development of male sheep: a meta-analysis}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {51-57}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {

Nutrient supply to the fetus is one of the crucial factors in the regulation of fetal growth and reproductive development. The effect of maternal nutrition can be exerted at all stages of fetal development, from conception until birth. A meta-analysis of maternal nutrition effects on the growth and reproductive development of male sheep offspring was undertaken using sixteen sheep studies. Eleven studies were included for prediction of the growth curves using a logistic growth model, and eleven studies were included for reproductive development and analysed using a mixed model. The meta-analysis suggested that, male sheep offspring undernourished during gestation had a significantly slower growth and lower testosterone levels while there were no statistically significant effects on testis weight, seminiferous tubule diameter or Sertoli cell count. The lack of a statistical effect on seminiferous tubule diameter and Sertoli cell count may be due to the limited number of studies examining the effects of maternal nutrition during pregnancy on male sheep offspring reproductive development. The meta-analysis reported here suggests that additional studies are warranted to more conclusively determine whether maternal nutrition during pregnancy effects male sheep growth and reproductive development.

}, issn = {1176-5283}, author = {Asmad K and Nakagawa S and Lopez-Villalobos N and Kenyon PR and Pain SJ and Blair HT} } @conference {79017, title = {Estimates of genetic parameters for flystrike in New Zealand Romney and Romney cross sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {189-191}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {

Myiasis, or flystrike, is a major animal welfare problem for sheep that causes significant production losses and potentially death. It is estimated that the prevalence of flystrike is 3-5\% in the national flock (Heath \& Bishop 1995) and is estimated to cost the New Zealand industry $40 to $50 million annually (Beef + Lamb New Zealand 1999). These costs accrue via production losses through reduced wool and body growth, morbidity, and control strategy costs including insecticide, lamb shearing and crutching. ... continued

}, issn = {1176-5283}, author = {Pickering NK and Dodds KG and Blair HT and Hickson RE and PL Johnson and McEwan JC} } @conference {78982, title = {An evaluation of a progesterone-based diagnostic as an aid to re-insemination decisions in a seasonal, pasture-grazed dairy cow herd}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {35-37}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {

Progesterone-based diagnostic tests are commercially available to predict pregnancy status 19 to 23 days following an insemination, thus providing decision-making support for artificial breeding. The study objective was to evaluate the likely performance of such a test in a pasture-grazed, seasonal dairy farm. Progesterone was determined in milk samples collected twice weekly from 553 cows at the Lincoln University Dairy Farm. Receiver operating characteristic analysis was applied to these data to determine sensitivity, false positive rate and the positive predictive value using a range of progesterone threshold values for detecting non-pregnant cows. The gold standard was non-pregnancy as measured by ultrasonography. At an optimised threshold of 4.1 ng/mL, the sensitivity, false positive rate and positive prediction rate were 78\%, 2.6\% and 96\% for detecting non-pregnant cows on Days 19 to 23. A major source of inaccuracy was the 28 cows with elevated levels of progesterone in milk on Days 19 to 23 after first insemination that were subsequently diagnosed non-pregnant. Another source of error was the inherent variance in progesterone concentration profiles among individuals. At a current cost of about $5 per test, this technology would have limited appeal for detecting non-pregnant cows in dairy systems where a satisfactory level of oestrus detection performance can be achieved.

}, issn = {1176-5283}, author = {Burke CR and Kamphuis C and Meier S and Pellow R} } @conference {78975, title = {Examination of New Zealand sport horse performance records and their suitability for the calculation of breeding values}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {3-7}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {

Currently there is no genetic evaluation of sport horses in New Zealand. The aim of this study was to develop a prototype model for genetic evaluation of New Zealand sport horses. Official performance data for the 2008/09 and 2009/10 seasons were obtained from Equestrian Sport New Zealand. Data on dressage points per start (Dpps), eventing points per start (Epps,) and show jumping total prize money (Stpm) were examined using descriptive statistics. There were between 902 and 1,472 horses registered in each discipline. All three data sets were skewed but approached normality after a log10 transformation. Overall between two and eight percent of sires in each discipline had five or more progeny records available for genetic analysis. A sire model with fixed effects of season, gender and age and a random effect of animal were used to calculate estimated breeding values (EBVs) for each discipline. EBVs for Dpps ranged from -0.066 to 0.158, for Epps from -0.076 to 0.182, and for Stpm from -0.523 to 0.993. The use of EBVs could lead to increased genetic gain and improved performance of New Zealand sport horses. However, the current data recording has several limitations.

}, issn = {1176-5283}, author = {Creagh FE and Lopez-Villalobos N and Hickson RE and CW Rogers} } @conference {79006, title = {Exploring the effects of growth rate and meat yield on lamb meat quality}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {150-151}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {

New Zealand sheep breeding programs currently place high emphases on selection for growth and yield. High growth rates and high meat yield have both been reported as having negative effects on meat quality in pig, beef and poultry (Dransfield \& Sosnicki 1999), probably due to changes in muscle structure and metabolism. In contrast, organic pork has shown to be less tender than conventional pork, which is thought to be due to organic pigs growing more slowly (Therkildsen et al. 2012). It is of importance to evaluate these relationships in lamb.

}, issn = {1176-5283}, author = {Campbell AW and Maclennan G and Lindsay S and Behrent MR and Cheong I and Kerslake JI} } @conference {78981, title = {Expression of uterine progesterone receptor in Suffolk and Cheviot ewes at Day 19 of pregnancy, following embryo transfer}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {35-37}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Many animal studies have shown that uterine capacity has a marked influence on birth weight and size (Walton \& Hammond 1938; Allen et al. 2002; Jenkinson et al. 2007; Sharma et al. 2012). However, in reciprocal embryo transfer experiments ... }, issn = {1176-5283}, author = {Sequeira M and Pain SJ and Sartore I and Meikle A and Kenyon PR and Blair HT} } @conference {79024, title = {Family-based selective breeding of New Zealand Abalone, Haliotis iris: challenges and opportunities}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {216-221}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {In 2007 the National Institute of Water and Atmospheric Research in New Zealand initiated a family-based selective breeding programme for the New Zealand Abalone, Haliotis iris, with commercial partner OceaNZ Blue Ltd. to investigate the genetics of key performance traits in a cold water and a warm water site and the influence of the early rearing environment on family performance. A total of 101 Abalone families were established using farmed and wild broodstock from multiple locations around New Zealand. Families were reared separately for nine to 14 months prior to tagging at ~15-20 mm shell length and then combined. Families were also pooled during early rearing, up to seven days post-fertilisation and later genotyped. This allowed estimation of individual tank environment effects on family performance. Length, weight and growth rate have been recorded bi-annually plus evaluation of quality traits such as foot darkness and shell colour at a market size of ~80 mm. Relative family performance has generally been consistent across sites, but is moderately influenced by early environment. The growth traits were found to be highly heritable with high genetic correlations among traits indicating good response to selection for increased growth can be expected.}, issn = {1176-5283}, author = {Symonds JE and Moss G and Jopson NB and Roberts R and Birss J and Heath P and Walker SP} } @conference {79007, title = {Genetic and phenotypic parameters for stayability in a New Zealand research flock}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {152-155}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Productive lifespan is important to commercial farmers, as ewes that are culled prematurely from the flock represent a considerable cost. The greater the number of replacements retained, the fewer the number of animals available for sale, and the greater proportion of the farm that must be allocated to rearing replacements at the expense of carrying more productive ewes. As selection occurs in stud flocks, Sheep Improvement Ltd. (SIL) developed an exit fate recording system that distinguishes between commercial culls of unsound sheep and the culling of sound sheep based on knowledge such as pedigree or genetic merit that would not usually be available to commercial breeders. Ewes culled for commercial ... continued}, issn = {1176-5283}, author = {McIntyre SB and Newman SAN and Young EA and McEwan JC} } @conference {79018, title = {Genetic and phenotypic relationships among flystrike indicator traits in the Earnscleugh stud Merino flock}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {192-195}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Increases in breech wrinkles, breech cover and dags have been shown to increase flystrike susceptibility of Merino sheep. At shearing at approximately 320 days of age in 2007, 2008 and 2009, breech wrinkle (1 to 5), dag score (1 to 5) and breech cover (1 to 5) were scored on 736, 806 and 866 yearlings that were the progeny of 31, 38 and 36 sires respectively. It was hypothesised that flystrike would become worse with an increasing score, where 5 indicated a very wrinkly, very daggy or very woolly breech. Fleece weight was recorded at shearing and fleece midside samples were collected and measured for washing yield. Breech wrinkle score (h{\texttwosuperior} = 0.25 {\textpm} 0.07), breech cover (h{\texttwosuperior} = 0.33 {\textpm} 0.08) and dag score (h{\texttwosuperior} = 0.10 {\textpm} 0.04) were found to be heritable. Breech wrinkle score and breech cover were phenotypically (0.39 {\textpm} 0.02, P < 0.05) and genetically correlated (0.40 {\textpm} 0.16, P < 0.05). Clean fleece weight was heritable (h{\texttwosuperior} = 0.33 {\textpm} 0.06) and showed a strong significant negative genetic correlation (-0.52 {\textpm} 0.14, P < 0.001) with breech cover. There was no evidence of flystrike during the three years of investigation, but this stud could decrease susceptibility by decreasing breech cover, breech wrinkles and dag score}, issn = {1176-5283}, author = {Scobie DR and Hickey SM and Campbell AK and Maslen DP} } @conference {78991, title = {Genetic parameters for lactose and its relationship with concentrations and ratios of other milk components}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {76-80}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {

The objective of this study was to estimate genetic parameters for milk yields, milk concentrations and ratios of milk components. Herd-test records from 268 Jersey cows from a Waikato dairy farm were obtained along with pedigree information. Genetic and phenotypic (co)variances for daily yields of milk (MY), fat (FY), protein (PY), milksolids (MSY; FY + PY) and lactose (LY), percentages of fat, protein, and lactose, and ratios of protein to fat (P:F) and protein to protein plus lactose (P:PL), and somatic cell score, were obtained with single trait and bivariate animal models using a restricted maximum likelihood methodology. The models included the fixed effects of month of calving and days in milk, modelled using an exponential curve, lactation number and the random effects of animal and cow permanent environment effects were also included in the model. Heritability estimates were 0.50 {\textpm} 0.12 (standard error) for MY, 0.25 {\textpm} 0.10 for FY, 0.30 {\textpm} 0.12 for PY, 0.27 {\textpm} 0.11 for MSY, 0.50 {\textpm} 0.12 for LY, 0.24 {\textpm} 0.04 for P:F ratio and 0.53 {\textpm} 0.04 for P:PL ratio. The genetic correlations for daily yields were high and positive. The genetic correlation between MSY and P:F ratio was -0.35 indicating that increases in MSY under the current breeding objective will decrease the P:F ratio, thus departing from an optimal ratio for whole milk powder processing.

}, issn = {1176-5283}, author = {Sneddon NW and Lopez-Villalobos N and Hickson RE and Shalloo L} } @conference {78994, title = {Genetically, Merino ewes that lose less live weight during joining have a higher chance of having lambs but the total weight of the born lambs is not affected}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {95-99}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Sheep in many areas of Australia and New Zealand experience periods of variable feed supply. Merino sheep can be bred to be more resilient to this varying feed supply. Resilient sheep lose less live weight when grazing poor quality pasture. However, we do not know if breeding for live weight change genetically affects reproduction. To estimate genetic correlations between live weight change and reproduction we used information from 6,870 fully pedigreed Merino ewes aged two- to four-years-old. Liveweight change was measured during joining (42 days) on low quality pasture and during lactation (130 days) on high quality pasture. Reproduction traits were total weight of lambs born and weaned and binary traits of whether or not a ewe gave birth to, or weaned, a lamb. Genetic correlations between live weight change and reproduction within age were estimated. There were moderate to high genetic correlations between live weight loss during joining and the chance of having and weaning a lamb. All other correlations were low. Therefore, change in live weight during joining affects the chance of having a lamb but not the weight of those lambs.}, issn = {1176-5283}, author = {Rose G and Mulder HA and van der Werf JHJ and Thompson AN and Ferguson MB and van Arendonk VAN} } @conference {78992, title = {"Grass to milk" and beyond}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {81-87}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Dr C.P. McMeekan{\textquoteright}s book, "Grass to milk", has been used as the basis of this paper. It is an historical account of a dairying system based on cows harvesting improved pastures in situ following a seasonally concentrated calving in the late winter. It was published in 1960, not as a text book, but as McMeekan{\textquoteright}s "complete philosophy of New Zealand dairy farming". The book{\textquoteright}s contents present an opportunity to compare "performance" statistics for the described dairying system with those recently published in the peer reviewed literature and elsewhere. Commendable advances have been made in cow yield per lactation and feed conversion efficiency as well as in dry matter harvested per hectare. However, these advances have been partly offset by an increase in cow wastage, largely due to lower reproductive performance, even in research herds, in spite of interventions such as induced calving and treating anoestrous cows. What should be obvious from reviewing the seminal publication of McMeekan is that most of the management concepts described by McMeekan have stood the test of time and are as relevant today as they were 50 years ago.}, issn = {1176-5283}, author = {Macmillan KL and Roche JR} } @conference {78996, title = {Grazing behaviour of dairy cows on simple and diverse swards in summer and autumn}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {106-110}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Increasing the proportion of dicotyledonous species such as herbs and legumes in dairy pastures may increase herbage dry matter intakes through ease of prehension. Simple swards consisting of either standard perennial ryegrass, high sugar ryegrass or tall fescue cultivars with white clover were established at the Lincoln University research dairy farm. Diverse swards were created by adding chicory and plantain to all mixtures, plus prairie grass and red clover to the perennial ryegrass, and praire grass and lucerne to the tall fescue. Grazing behaviour of cows during a two hour grazing session was monitored in summer and autumn. In summer, Diverse swards had a greater compressed sward surface height, lower mass and bulk density. Cows grazing Simple swards achieved a greater bite rate (49.3 vs 43.8 bites/min respectively (P < 0.05)). In autumn, all pasture swards had lower mass and contained a higher proportion of grass species than in summer. Bite rate was greater on Diverse compared with Simple swards (60.3 vs 54.3 bites/min respectively (P < 0.05)). Lower bite rate on Simple swards was compensated for by increasing grazing duration (P < 0.001). Sward type influenced bite rate adaptations.}, issn = {1176-5283}, author = {Bryant RH and Miller ME and Edwards GR} } @conference {79028, title = {Heritability and repeatability of resistance to nematode parasites in commercial beef cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {236-239}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Faecal egg count (FEC) is used commonly as a guide to nematode parasite burdens in animals in vivo. The objective of this study was to estimate the heritability and repeatability of FEC in commercial beef calves, along with breeding values for FEC in the calves and their sires, for future quantitative and molecular analyses. In 2008-2011, faecal samples from 4,621 weaned beef calves were obtained for FEC1 from 11 herds (mainly Angus or Hereford). FEC1 represented the first sample after weaning generally between May and July); a second sample (for FEC2) was taken by September from all calves in some herds, with FEC1 and FEC2 samplings separated by an effective anthelmintic drench. Calves were sired by a total of 325 and 57 separate Angus and Hereford sires, respectively. Heritability estimates for loge(FEC+50) in Angus at Times 1 and 2 were 0.28 {\textpm} 0.05 (standard error) and 0.11 {\textpm} 0.09, respectively, with a genetic correlation of 0.89 {\textpm} 0.22 between them. Treating FEC1 and FEC2 as repeated measurements of the same trait, the repeatability estimate for loge(FEC+50) was 0.38 {\textpm} 0.04. The parameters estimated for loge(FEC+50) in weaned beef calves under commercial grazing conditions were similar to those from experimental beef calves.}, issn = {1176-5283}, author = {Morris CA and Amyes NC} } @conference {79029, title = {Host-defence related bioactive proteins in cows{\textquoteright} milk during mastitis and after drying-off}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {240-242}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Besides the caseins and major whey proteins, cows{\textquoteright} milk contains a wide range of less abundant proteins that have functions associated with host defence, and are thought to play a role in protection against microbial infections (Stelwagen et al. 2009; Wheeler et al. 2007). Microarray analysis has shown that complex changes in gene expression occur in the bovine mammary gland in response to drying-off, including up-regulation of host-defence associated genes (Singh et al. 2008). The abundance of at least some proteins encoded by these genes can be altered in response to milking frequency and at different stages of the lactation cycle.}, issn = {1176-5283}, author = {Backmann EC and Hine BC and Broadhurst and Kim K and Smolenski GA and Stelwagen K and Wheeler TT} } @conference {79015, title = {Identification of cost-effective management options for reducing greenhouse gas emissions by 10\% on a dairy farm in Waikato, New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {181-185}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {An optimisation model of a dairy farm was built to estimate the cost of mitigation of greenhouse gas emissions (GHG-e). First, the Farmax and Overseer models were used to describe production, profitability, and emissions to the environment of a medium-input dairy farm system for the Waikato-Bay of Plenty region of New Zealand. This process allowed generation of a valid and consistent set of input data for a detailed nonlinear programming model able to optimise resource use. The optimisation model was then used to investigate how producers may best respond to the introduction of a 10\% restriction on GHG-e, with and without the use of strategic changes to their farm system to mitigate GHG-e. Profit decreased by 8\% when the restriction was introduced without the availability of strategic mitigation options. The variables that changed most to achieve the reduction were nitrogen fertiliser input, which was reduced by 58\%, and stocking rate which was reduced by 7\%. In contrast, profit increased by 5\% when strategic mitigation options were used under GHG-e restrictions. Using high genetic merit cows was enough to achieve this increase in profit under the emissions constraint.}, issn = {1176-5283}, author = {Adler AA and Doole aj Romera GJ and Beukes PC} } @conference {79005, title = {Impacts of different forages and packaging conditions on colour and lipid oxidation stability of lamb loins}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {147-149}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Fresh meat colour is one of the most important quality attributes that affects the consumer{\textquoteright}s meat purchasing decisions (Renerre \& Labas 1987). A number of factors such as feed type, animal breed, age, sex, display and packaging conditions influence the rate of metmyoglobin formation. Metmyoglobin is the pigment responsible for brown colour on meat surface during retail display ... continued}, issn = {1176-5283}, author = {Kim YHB and Stuart AD and Rosenvold K and Maclennan G} } @conference {79019, title = {In vitro evaluation of the antimicrobial effects of chitosan against bacteria involved in ovine footrot}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {196-198}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Virulent footrot of ovines is caused by a mixed infection of Dichelobacter nodosus and Fusobacterium necrophorum; anaerobic, non-spore forming Gram negative bacilli. Footrot has a significant economic impact on the farming industry within New Zealand (Hickford et al. 2005). When the interdigital skin of the ovine foot is damaged, or wet for a prolonged period, it may be infected by F. necrophorum, a member of the gut flora, which causes ovine interdigital dermatitis. The skin becomes red and swollen and bacterial toxin production results in necrosis in the upper layers of the skin enabling D. nodosus to establish if the organism is present in the flock or the environment. ... continued}, issn = {1176-5283}, author = {Mros S and Ali MA and Ghosh A and El-din Bekhit A and McConnell M} } @conference {78995, title = {In vitro fermentation of [15N-] ryegrass and ruminal digesta of sheep grazing a ryegrass-based pasture in the morning or in the afternoon}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {100-105}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {

Sheep in many areas of Australia and New Zealand experience periods of variable feed supply. Merino sheep can be bred to be more resilient to this varying feed supply. Resilient sheep lose less live weight when grazing poor quality pasture. However, we do not know if breeding for live weight change genetically affects reproduction. To estimate genetic correlations between live weight change and reproduction we used information from 6,870 fully pedigreed Merino ewes aged two- to four-years-old. Liveweight change was measured during joining (42 days) on low quality pasture and during lactation (130 days) on high quality pasture. Reproduction traits were total weight of lambs born and weaned and binary traits of whether or not a ewe gave birth to, or weaned, a lamb. Genetic correlations between live weight change and reproduction within age were estimated. There were moderate to high genetic correlations between live weight loss during joining and the chance of having and weaning a lamb. All other correlations were low. Therefore, change in live weight during joining affects the chance of having a lamb but not the weight of those lambs.

}, issn = {1176-5283}, author = {Vibart RE and Tavendale MH and Burke JL and Pacheco D} } @conference {78998, title = {Maintenance energy requirements of non-lactating, pregnant dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {117-119}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {A number of estimates of metabolisable (ME) and net energy (NE) requirements for maintenance, activity, reproduction and productive purposes have been published (AFRC 1995; ARC 1980; CSIRO 2007; NRC 2001). The most appropriate recommendations for New Zealand systems have been compiled by Nicol \& Brookes (2007).}, issn = {1176-5283}, author = {Mandok KS and Greenwood SL and Kay JK and Crookenden M and Roche JR} } @conference {78977, title = {Milk somatic cells are not suitable biomarkers of lactating ruminant mammary gland function}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {3-7}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {

Understanding the molecular regulation of milk production by the ruminant mammary gland may help farmers meet increasing production milestones. Investigating these mechanisms currently relies upon invasive sampling by post-mortem or biopsy. The objective of this study was to determine if milk somatic cells, shed by the gland during milking, could be used as a non-invasive source of cells to measure these mechanisms. To answer this we employed two widely used molecular techniques, biochemical indices and quantitative polymerase chain reaction (qPCR). Experiment 1: Biochemical indices as measures of cell size, protein production capacity and efficiency were determined in milk somatic cells and mammary tissue harvested from six lactating dairy goats. Results showed protein production capacity (P = 0.03) and cell size (P = 0.03) were higher in mammary tissue compared to somatic cells while protein production efficiency was unaffected (P = 0.55). Experiment 2: Milk protein and ribosomal RNA gene expression were measured using qPCR in milk somatic cells and mammary tissue collected from three lactating dairy cows treated with growth hormone and four treated with saline. Results showed expression of all genes differed between milk somatic cells and mammary tissue. Taken together, these results indicate milk somatic cells are not suitable for measuring biochemical indices or gene expression in the lactating ruminant mammary gland.

}, issn = {1176-5283}, author = {Sciascia Q and Pacheco D and Senna Salerno M and Blair HT and McCoard SA} } @conference {79001, title = {Once-daily milking during a feed deficit improves energy status in early lactating dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {129-133}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {The aim of this study was to determine the effect of once-daily (1X) milking during a feed deficit on energy status of grazing dairy cows. Multiparous cows (n = 120), grazing to residuals of 1,600 kg DM/ha, and milked twice-daily (2X) from calving until approximately 35 days-in-milk, were allocated to one of four treatments in a 2 x 2 factorial arrangement. Cows were adequately fed (14 kg DM/cow/d) or underfed (8 kg DM/cow/d) and milked 2X or 1X for three weeks, after which all cows were milked 2X and grazed to residuals of 1,600 kg DM/ha for 20 weeks. During the three-week treatment period, plasma concentrations of glucose, insulin and insulin-like growth factor-I (IGF-I) were less in underfed compared with adequately cows, while non-esterified fatty acids (NEFA), β-hydroxybutyrate (BHBA) and liver enzymes were greater. An interaction existed and the increase in liver enzymes with underfeeding only occurred in cows milked 1X. Cows milked 1X had greater plasma glucose, insulin and IGF-I and less NEFA and BHBA than those milked 2X. Data indicate that milking cows 1X during an acute feed deficit improves energy status.}, issn = {1176-5283}, author = {Kay JK and Phyn CVC and Rius AG and Morgan SR and Grala TM and Roche JR} } @conference {79022, title = {Is placentome size more important than morphologic type in relation to fetal weight in sheep?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {210-212}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {In sheep, placental exchange of nutrients between the ewe and her fetus occurs at sites called placentomes (Ford 2000). Placentomes are comprised of cotyledons on the chorioallantoic membrane which attach to discrete caruncles on the uterine wall (Ford 2000). Ovine placentomes can be classified into four types on the basis of their gross morphological appearance (Vatnick et al. 1991). The distribution of placentome type and size of individual placentomes can be influenced by many factors such as, nutritional state, placental blood flow and oxygen availability (Gardner et al. 2002; Osgerby et al. 2004). In general, previous work has shown that adverse intrauterine conditions early in pregnancy lead to a shift to more everted placentomes (more C and D types) (Osgerby et al. 2004; Vonnahme et al. 2006).}, issn = {1176-5283}, author = {van der Linden DS and Sciascia Q and Sales F and McCoard SA} } @conference {79008, title = {Potential for genomic selection of bovine embryos}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {156-158}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Sexual reproduction is a genetic lottery. There is no guarantee that offspring receive a favourable combination of genes from their parents to form their genotype. For animal breeding, the conventional way of selection has been based on phenotyping adults or their progeny. Increasingly, however, dairy cattle breeding schemes are integrating the use of genomic selection of juvenile and adult candidates (Hayes et al. 2009; Pryce et al. 2010). To further increase the intensity of selection and accelerate the rate of genetic gain, we aim to genomically select bovine embryos within one week after in vitro fertilisation (IVF) using gametes from elite parents. The generation of multiple embryos from multi-factorial ... continued}, issn = {1176-5283}, author = {Fisher PJ and Hyndman DL and Bixley MJ and Oback FC and Popovic L and McGowan LT and Berg MC} } @conference {79013, title = {Preliminary examination of wastage in Thoroughbred and Standardbred horses in New Zealand using training milestones}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {172-174}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {

The production of Thoroughbred and Standardbred horses to race is a multi-million dollar industry in New Zealand. However, wastage studies have shown that as many as 50\% of foals born fail to race (Wilsher et al. 2006; Jeffcott et al. 1982; Perkins et al. 2004a; Perkins et al. 2004b). Wastage, defined as losses that occur during the production of horses to race, is a major cause for concern in the racing industry and has both animal welfare and economic implications. Wastage may be caused by several factors including lack of ability, physical injury or financial decision by owners and can occur at any stage from conception through to competing at the races. ... continued

}, issn = {1176-5283}, author = {Tanner JV and Rogers CW and Bolwell CF and Gee EK} } @conference {78978, title = {Prenatal maternal effects on daughter milk production in New Zealand dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {19-22}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {

The impact of a cow{\textquoteright}s live weight and body condition score (BCS) during pregnancy on the milking performance of a resulting daughter was investigated using 4,021 Jersey and 9,329 Holstein Friesian dam-daughter pairs from the Livestock Improvement Corporation Sire Proving Scheme. Although the estimated maternal heritability of each trait in each breed was small (\< 0.02), a l kg increase in dam weight was associated with 1.19 ({\textpm} 0.25) and 0.43 ({\textpm} 0.15) litres increase in daughter milk volume, a 61 ({\textpm}11) and 15 ({\textpm}6) gram increase in fat and a 55 ({\textpm} 8) and 14 ({\textpm}5) gram increase in protein in Jersey and Holstein Friesian cows respectively. A one unit increase in BCS was associated with an increase in volume by 32 ({\textpm} 19) litres in Jerseys and a 14 ({\textpm} 14) litre decrease in Holstein Friesians. Fat increased by 1.91 ({\textpm} 0.84) kg and 0.56 ({\textpm} 0.55) kg and protein increased by 1.64 ({\textpm} 0.63) kg and 0.06 ({\textpm}0.42) kg per unit BCS in Jersey and Holstein Friesian respectively. All daughter responses are per lactation. Although small changes in the daughters milking traits were observed, the lack of significant variation in the maternal heritability indicates that the sample size of the dataset may not be sufficient to detect if prenatal maternal effects truly exist.

}, issn = {1176-5283}, author = {Gudex BW and Johnson DL and Singh K} } @conference {78974, title = {Presidential Address 2011 - The changing face of agriculture}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {1-2}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {

Agriculture is continually changing. For a large part change is essential, from the seasonal changes in animals and plants through to the inevitable changes in land use and labour requirements as technological improvements and market forces take effect. Indeed, things have changed somewhat since I was a young boy growing up on a farm in rural Southland. In my youth I would have had to travel for nearly an hour to the nearest dairy farm. But by the time I was at university, about ten years ago, the district had started to ... continued

}, issn = {1176-5283}, author = {Greer AW} } @conference {79014, title = {Productivity and financial characteristics of herds that produce milkfat with different concentration of unsaturated fatty acids using a stochastic farm model}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {175-180}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {The objective of this study was to describe the characteristics of dairy farms with different concentrations of unsaturated fatty acids (UFA) in milkfat using a stochastic farm model. Daily phenotypic cow performance was simulated using an exponential function including terms for milk, fat, protein and live weight, and a third order orthogonal polynomial of milkfat UFA concentration. Daily and yearly feed requirements were estimated from metabolisable energy requirements for maintenance, lactation, pregnancy and growth. Two groups of farms were simulated: (1) Average UFA farms (30 farms, milkfat UFA concentration = 30.04 g/100g milkfat) and (2) High UFA farms (30 farms, milkfat UFA concentration = 35.99 g/100g milkfat). Each farm was 140 ha and had 386 cows, a replacement rate of 18\% and a spring calving between 20 July and 10 September. The simulation was replicated 1,000 times. High UFA farms produced significantly (P < 0.05) less milkfat (338 vs 502 kg/ha) and milksolids (692 vs 927 kg/ha) than Average UFA farms. This resulted in High UFA farms having lower (P < 0.05) gross farm income ($3815 vs $5075 /ha) and cash operating surplus ($-331 vs $598/ha) than Average UFA farms. This highlights the need to develop a payment system that rewards concentration of UFA in milkfat.}, issn = {1176-5283}, author = {Silva-Villacorta D and Lopez-Villalobos N and Blair HT and Hickson RE and MacGibbon AKH} } @conference {78993, title = {The random bouncing ball}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {88-94}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {A retrospective, biased, personal review of a contribution to animal production research. The review covers aspects of animal behaviour; maternal behaviour, and deer behaviour. It recalls studies on the effect of the heat of warming feed on the lower critical temperature of ruminants and summarises more recent studies on analgesia of the antlers of yearling stags. A significant proportion of the review revolves around work in grazing ecology mainly mixed animal species grazing. Deer are equivalent to sheep in grazing around cattle dung pats; goats have a similar dietary preference for clover as sheep unless the clover is short; cattle are disadvantaged when continuously grazed with sheep, but not with rotational grazing; diet composition is markedly affected by mixed grazing.}, issn = {1176-5283}, author = {Nicol AM} } @conference {78987, title = {The relationship between milk synthesis and intracellular profiles of amino acids in the bovine mammary gland}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {63-66}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {

There is a growing body of evidence that amino acid (AA) signalling in the mammary gland may play a key role in milk production of ruminants through modulation of translational regulation (Moshel et al. 2006; Toerien \& Cant 2007). It has been postulated that the effect of nutrient signalling on elements of translational control of milk protein synthesis may contribute to the variable responses of milk protein yield observed following nutritional perturbations (Hanigan et al. 1998). Consistent with this hypothesis, we have reported that changes in the mean and variance of intracellular free AA (FAA) in the bovine mammary gland are associated with ... continued

}, issn = {1176-5283}, author = {McCoard SA and Pacheco D and Treloar BP and Wards N and Swanson K and Singh K} } @conference {79023, title = {Relationship between profiles of free amino acids in fetal and maternal plasma with those in skeletal muscle, in twin and single fetuses from ad-libitum fed ewes in late gestation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {213-215}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Skeletal muscle growth depends on amino acid (AA) availability, not only as building components, but also as regulatory signals for protein accretion (Wu 2009). However, their signalling role for muscle growth in ruminants is poorly understood. We have previously reported that lower muscle weight in twin compared to single fetuses in late gestation, is associated with changes in the profile of specific intracellular muscle free AA (FAA), when ewes are fed a maintenance plane of nutrition during gestation (Pacheco et al. 2010a). This suggests that some AA may regulate muscle growth during fetal life.}, issn = {1176-5283}, author = {Sales FA and Treloar BP and Pacheco D and Blair HT and Kenyon PR and Nicholas G and Senna Salerno M} } @conference {78980, title = {Relative performance of Wiltshire and Perendale sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {28-34}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {

Performance data are reported for flocks of Wiltshire and Perendale sheep grazed together for four years on a North Island hill country property (Whatawhata) and for four years on a South Island breeding/finishing property (Winchmore). Wiltshire ewes were lighter than Perendale ewes post-joining at Whatawhata, and at weaning at Winchmore. Greasy fleece weights of the Wiltshire and Perendale yearlings were 0.8 and 2.2 kg respectively, and 0.5 and 3.3 kg respectively for the ewes. As a result of a confounding effect of fibre shedding between day length and date of shearing, Wiltshire ewes exhibited a linear decrease in harvested fleece weight from the yearling stage whereas Perendale ewes showed a curvilinear age effect, with a maximum fleece weight at three to four years of age. Wiltshire ewes had a significantly lower reproductive rate, and lamb survival than Perendale ewes at both locations, with reproductive rate, fertility and litter size increasing significantly following the transfer of the flocks from Whatawhata to Winchmore. While there was no significant difference in the total weight of lambs weaned by the two breeds at each location, the loss in wool production would be compensated by lower shearing and management costs for Wiltshire sheep that shed completely.

}, issn = {1176-5283}, author = {Sumner RMW and Scobie DR and O{\textquoteright}Connell D and Henderson HV} } @conference {78997, title = {Rumen fermentation characteristics are influenced by feeding frequency in sheep fed forage chicory and perennial ryegrass at two feeding levels}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {111-116}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {The objective of this study was to investigate the effects of feeding frequency and level of intake on rumen fermentation parameters of sheep fed chicory or perennial ryegrass. Fresh, vegetative chicory or perennial ryegrass were fed twice daily at 0900 h and 1630 h in the first period, and hourly in the second period to eight rumen-fistulated wethers at 1.3 and 2.2 times their maintenance metabolisable energy requirements. Rumen fluid pH, ammonia and volatile fatty acid (VFA) concentrations at 0900, 1000, 1100, 1200, 1300 and 1500 h were determined. When fed hourly (P < 0.05), but not twice-daily, forage type and feeding level significantly affected rumen pH. Differences in total VFA concentrations between forages and feeding levels were influenced by feeding frequency. Ammonia concentrations were always lower in sheep fed chicory than ryegrass (P = 0.001). Differences in rumen pH, ammonia and total VFA concentrations attributed to either forage species, level of intake or their interactions and were more likely to be detected when sheep were fed hourly, compared to twice-daily, as a result of the reduction in diurnal variation of these parameters. Manipulation of feeding frequency and/or feed intake can modulate the responses of ruminal metabolism to fresh forage diets.}, issn = {1176-5283}, author = {Sun XZ and Pacheco D and Hoskin SO and Luo DW} } @conference {79016, title = {The use of milking intervals of individual cows in assessing herd test milk production data}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {186-188}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {

Herd testing is a significant expense for dairy farmers but it gives important information about individual cow yields and contributes to the genetic worth status of the cows. While every effort is made to maximise the value of the tests to the farmer there are still opportunities to increase this value further. Estimations of milk yield from herd tests, whether from one or two milkings, rely on the generally held assumption that animals come in to the parlour in a similar order at each milking (DairyNZ 2011) and so the values obtained reflect a nominal 24 hour yield. ... continued

}, issn = {1176-5283}, author = {Molenaar AJ and Henderson HV and ML Burgess and Burgess WG and Johnson DL and Singh K} } @conference {78984, title = {Use of progesterone profiling to investigate factors affecting conception rates in a large, pasture-grazed dairy herd}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {45-50}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {

A study was conducted at the Lincoln University Dairy Farm to investigate factors influencing conception rate (CR). Relative to the planned start of mating date (Day 0), milk progesterone (MP4) concentrations were determined weekly from Day -20 to 0, twice weekly from Day 0 to 42, and then weekly to Day 70 in 666 cows. Trough-like patterns among individual profiles were identified and defined as periovulatory events. Pre-mating ovulatory status was a predictor (P \< 0.01) of first service CR (FSCR), with anovulatory cows having a lower FSCR (37.4\%) compared with {\textquoteleft}late{\textquoteright} (47.3\%) and {\textquoteleft}early{\textquoteright} (56.4\%) ovulating cows. In turn, interval from calving to Day 0 was a significant determinant for pre-mating ovulatory status. Oestrus detection was performed to a high standard, even though 5\% of the 850 artificial inseminations were coincident with a lack of ovulation. MP4 profiles also indicated that 4\% of cows that conceived during the 37-day artificial breeding period subsequently lost these pregnancies. A 2.6\% error rate for diagnosing pregnancies on Day 78 was detected, mostly due to incorrectly attributing pregnancies following artificial breeding. Findings indicate the critical importance of managerial strategies that promote a high prevalence of cows having ovulated at least 21 days before mating starts.

}, issn = {1176-5283}, author = {Burke CR and Meier S and Pellow R} } @conference {79003, title = {Validation of a bio-economic dairy production model}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {139-143}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {DairyMax is an internet-based bio-economic dairy production model that uses a deterministic cow model to establish response curves of milksolids (MS; fat plus protein) production to energy intake at different stages of lactation and nutrient requirements for different levels of production. Another component in DairyMax is a linear programming module that uses farm-related constraints, market prices for supplements, cost of pasture and silage production and cow-related constraints to optimise a feeding strategy based on a maximum profit algorithm. The objective of this study was to validate the cow model of DairyMax against published field work conducted in New Zealand. In DairyMax, the stocking rate was adjusted to get the same MS production as in the experiment. The dry matter intake (DMI) associated with the different production levels were compared assuming energy content of 11.2 MJ ME/kg dry matter, similar to that reported in a three-year field experiment. The ability of the model was satisfactory in predicting yearly DMI per cow (Concordance correlation coefficient = 0.98). Productive performance, DMI and feed conversion efficiency (ratio between DMI and MS) of dairy cows under different stocking policies can be predicted by DairyMax with satisfactory accuracy.}, issn = {1176-5283}, author = {Visser A and Lopez-Villalobos N and Morel PCH} } @conference {78986, title = {Variation of milk composition traits among Holstein-Friesian-sired cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {58-62}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {

A pooled afternoon and morning milk sample was obtained from each of 3,789 cows of known pedigree during a standard herd-test carried out in 21 North Island spring-calving herds between November and February. The cows were all sired by one of 11 Holstein-Friesian bulls, in a sampling design intended to sample milk from many daughters per sire, for segregation studies. Routine herd-test data consisted of 24 hour milk yield, protein \%, fat \% and somatic cell count. Samples were measured at Ruakura for fatty acid composition, fat melting point, and the concentrations of the following components, lactoferrin, β-lactoglobulin, β-casein, κ-casein, and total carotenoids. After liaison between AgResearch Ruakura staff and each dairy farmer a variate describing the current grazing groups of cows were included in analyses. Coefficients of variation were calculated for each milk component, and ranged from 0.04 to 0.35. Phenotypic correlations among components were estimated. The correlations were negative between the percentage of mono-unsaturated fatty acids present in milkfat and both the protein \% (-0.26 {\textpm} 0.03 (standard error)) and fat \% (-0.38 {\textpm} 0.02) of the milk. Some implications of selection mainly for yield from cows at pasture are discussed in terms of likely effects on milk composition.

}, issn = {1176-5283}, author = {Cullen NG and Hickey SM and Morris CA} } @conference {78983, title = {Weight management considerations prior to mating to control litter size in Inverdale ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {42-44}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {

Nutritional flushing of ewes prior to mating is a routine component of many commercial farming operations to maximise profitability by increasing the number of lambs born per ewe. In the 1990s, the Inverdale mutation ... continued

}, issn = {1176-5283}, author = {Smaill B and Juengel JL and Davis GH and Demmers KJ} } @conference {75900, title = {Animal welfare policy and science - keeping up with a changing world}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {178-181}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {

New Zealand{\textquoteright}s animal welfare laws and policies are backed by sound animal welfare research that is internationally recognised for its quality. Indeed, the Animal Welfare Act 1999 requires scientific knowledge to be considered in the development of animal welfare standards in codes of welfare. Research needs are identified and prioritised to meet the requirement for scientific knowledge. However, animal welfare also requires a consideration of societal views, good practice and available technology. Can research also help in the consideration of these other factors? Here we consider these issues in the wider context of applying science to policy development under changing societal expectations.

}, issn = {1176-5283}, author = {O{\textquoteright}connor CE and Littin KE} } @conference {75910, title = {The apparent digestibility of palm kernel expeller (PKE) consumed by pasture-fed sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {223-228}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {

Palm kernel expeller (PKE) usage in New Zealand has increased despite little being known about its nutritional role as a supplement in pasture based diets. The chemical composition of PKE is often reported in New Zealand, but the digestibility is not. A digestibility study was conducted with twenty four lambs fed one of four different amounts (0, 15, 30 or 45\%) of their dry matter (DM) intake as PKE, plus molasses pellets (PKEM; 90\% PKE and 10\% molasses) with the remainder of the diet being fresh pasture. Sheep were fed at either maintenance or ad libitum during two experimental periods, that differed in pasture quality. Digestibilities were extrapolated linearly to estimate digestible energy concentration and the apparent digestibility of DM, crude protein, neutral detergent fibre and gross energy at any intakes for a diet consisting of 100\% PKEM. Overall, the estimated apparent digestibility of DM, crude protein, neutral detergent fibre and gross energy for PKEM at intakes of 670 and 1,214 gDM/lamb/day were 63.0, 52.0, 67.0 and 64.0\%, respectively. The values estimated for digestible energy concentration (MJ/kgDM) of PKEM ranged between 12.4-12.7, from which values for metabolisable energy concentration of 10.2 and 10.5 MJME/kgDM could be calculated.

}, issn = {1176-5283}, author = {Burke JL and Dias FN and Pacheco D and Lopez-Villalobos N and Holmes CW} } @conference {75884, title = {Are high breeding worth index cows more feed conversion efficient and nitrogen use efficient?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {109-113}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {Future dairy farming in New Zealand will require increases in milksolids production and reduced impact on the environment. Cows which are more feed conversion efficient (FCE) and nitrogen use efficient (NUE) will help achieve these targets. In March 2010, eight High breeding worth (BW = 198), High production worth (PW = 319) and eight Low BW (57) PW (10) cows were housed in metabolism stalls and fed low quality perennial ryegrass-based herbage (metabolisable energy = 9.87 MJ/kg DM; crude protein = 15.2 g/100g DM). High BW cows had higher dry matter intakes (DMI) (16.0 vs 14.8 kg DM/cow/d, P <0.05) and produced more milksolids (1.32 vs 1.03 kg MS/cow/d, P <0.001). Due to their higher DMI, the High BW cows also had a higher feed N intake than the Low BW cows (388 vs 360 g N/cow/d, P <0.05), and partitioned more of their intake N to milk (22.0 vs 18.5 \%, P <0.01) and less to urine (39.7 vs 46.2\%, P <0.01). Overall, the High BW cows were more FCE (82.7 vs 70.2 g MS/kg DMI, P <0.01) and more NUE (22.0 vs 18.5 \%, P <0.01) when fed low quality herbage in late lactation.}, issn = {1176-5283}, author = {Woodward SL and Waghorn GC and Bryant MA and Mandok K} } @conference {75875, title = {The association of ewe body condition score with weight of lamb weaned}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {62-65}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {Data from 1,301 ewes lambing in 2009 were analysed to investigate the association of body condition score (BCS) with total lamb weaned (TLW). BCS was assessed on a scale of 0-5 at mating (BCSM), scanning (BCSS), pre-lambing (BCSL) and weaning (BCSW) and categorized as <3, 3-3.5 and >3.5. Ewe age, flock, live weight at mating (LWM) and date of lambing (DOB) had significant effects on TLW (P <0.05). Ewes having triplets at birth with >3.5 and 3-3.5 BCSM had a higher TLW (63.2, 63.0 kg respectively; P<0.05) than ewes with triplets at birth and <3 BCSM (56.1 kg). Ewes with 3-3.5 BCSS had higher TLW than ewes with >3.5 BCSS for all birth ranks (49.8 kg, 47.2 kg respectively, P <0.05). There was no association between BCSL and TLW. Ewes with <3 or 3-3.5 BCSW had a significantly higher TLW than ewes with >3.5 BCSW (>3.5 = 43.8 kg, 3-3.5 = 48.9 kg, <3 = 50.9 kg; P <0.001). This study indicates ewes with 3-3.5 BCSS or <3 or 3-3.5 BCSW outperform ewes with >3.5 BCSS or >3.5 BCSW.}, issn = {1176-5283}, author = {Mathias-Davis HC and Shackell GH and Greer GJ and Everett-Hincks JM} } @conference {75915, title = {BRIEF COMMUNICATION: Arapawa: a novel New Zealand sheep breed of distinct origin}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {248-250}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {Arapawa sheep are a feral breed found on Arapawa Island in the Marlborough Sounds, New Zealand. Their origin is not documented, but it is thought to be one of the oldest feral flocks in New Zealand dating back to approximately mid 1800s (Orwin et al., 1984). There are numerous... Continued}, issn = {1176-5283}, author = {Young EA and Kijas JW and Mcculloch R and Scobie DR and Mcrae KM and Pickering NK and Dodds KG and McEwan JC} } @conference {75867, title = {BRIEF COMMUNICATION: Comparison of the performance of dairy cows offered energy supplements prior to drying off and kale at high and low allowance during the dry period in winter}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {33-36}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {Forage availability and body condition score (BCS) of the dairy cow are important aspects of dairy livestock management during the dry and peripartum period. New Zealand guidelines recommend a target BCS of 5.0 at calving (1-10 scale where 1 = Emaciated and 10 = Obese, Roche et al., 2009). Providing adequate forage to meet... Continued}, issn = {1176-5283}, author = {Greenwood SL and Dalley DE and Purdie NG and Rugoho I and Bryant RH and Edwards GR} } @conference {75885, title = {BRIEF COMMUNICATION: DNA methylation patterns in bovine blastocysts suggest that only limited epigenetic reprogramming has occurred in the early embryo}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {114-116}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {Epigenetics is the study of changes in phenotype caused by mechanisms other than changes in the underlying DNA sequence. In agriculture, epigenetics largely resides in the environment component of the equation; Phenotype = Genotype + Environment. Epigenetic mechanisms include but are not limited to, DNA methylation, acetylation and... Continued}, issn = {1176-5283}, author = {Couldrey C and Wells DN and Lee RSF} } @conference {75922, title = {BRIEF COMMUNICATION: Effect of gender and prior exposure on the intake and preference of sheep for plantain post-weaning}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {278-280}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {Animals are exposed to a sensory learning environment both pre- and post-birth birth (Nicolaidis, 2008). Numerous experiments with rats (Smotherman, 1982), chickens (Porter \& Picard, 1998; Sneddon et al., 1998) and sheep (Nolte et al., 1992; Schaal et al., 1995; Simitzis et al., 2008) have demonstrated prenatal... Continued}, issn = {1176-5283}, author = {Pain SJ and Kenyon PR and Morris ST and Kemp PD} } @conference {75869, title = {BRIEF COMMUNICATION: Effect of milking frequency and concentrate supplementation on milk production during an extended lactation in grazing dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {42-44}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {Extending the lactation for longer than 300 days can be used to maintain a high level of milk production, improve reproductive function, and animal welfare. Extended lactations of ~600 days in milk (DIM) in pasture-based systems could benefit the dairy industry by maintaining a relatively constant milk supply throughout the season, improving labour conditions, and reducing on-farm costs (Kolver et al., 2007). Milk production during an extended lactation is dependent... Continued}, issn = {1176-5283}, author = {Rius AG and Phyn CVC and Kay JK and Morgan SR and Grala TM and Roche JR} } @conference {75907, title = {BRIEF COMMUNICATION: Effect of red wine lees on lamb meat quality}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {211-213}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {Oxidative processes in fresh red meat can cause detrimental effects on the keeping and eating qualities of meat as well as its nutritional value (Bekhit {\textpm} Faustman, 2005; Bekhit et al., 2007). Several supplement feeding strategies have been shown to improve the colour stability of fresh meat during display such as Vit E (Faustman et al., 1989) and condensed... Continued.}, issn = {1176-5283}, author = {Bekhit AED and Richardson A and Maclennan G and Lindsay S and Grant C} } @conference {75921, title = {BRIEF COMMUNICATION: Effects of handling during calf rearing on behavioural and physiological responses of one year-old dairy heifers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {275-277}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {Interaction with humans is a daily part of most farm animal{\textquoteright}s lives. The nature of these interactions is an important factor contributing to animal welfare and productivity. Exposure to negative handling can increase fearfulness in animals, which can cause problems such as increased handling time, poor meat quality and... Continued}, issn = {1176-5283}, author = {Stewart M and Worth G and Webster JR and Sch{\"u}tz KE} } @conference {75913, title = {BRIEF COMMUNICATION: Evaluating rumen fluid from sheep and cattle as inoculum in a newly developed automated in vitro rumen batch culture system}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {240-242}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {In vitro rumen batch culture systems are widely used to rank feeds according to their rate of fermentation, potential gas production and in vitro digestibility. Their main advantage is that the analysis is quick and... Continued}, issn = {1176-5283}, author = {Muetzel S and Hunt CL and Tavendale MH} } @conference {75918, title = {BRIEF COMMUNICATION: Genomic selection in the New Zealand Sheep industry using the Ovine SNP50 Beadchip}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {263-265}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {The Illumina OvineSNP50 BeadChip is a single nucleotide polymorphism (SNP) microarray targeting 54,241 evenly spaced SNPs on the sheep genome, developed by Illumina in collaboration with AgResearch, Baylor, UCSC, CSIRO, and the USDA as part of the International Sheep Genomics Consortium. It was used to genotype key... Continued}, issn = {1176-5283}, author = {Auvray B and Dodds KG and McEwan JC} } @conference {75927, title = {BRIEF COMMUNICATION: Liveweight gain of grazing dairy calves in their first season subjected to a targeted selective anthelmintic treatment (TST) regime}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {301-303}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {For some time now it has been recognised that suppressive anthelmintic regimes select strongly for resistance (Jackson \& Miller, 2006). However, despite widespread anthelmintic resistance on beef properties in New Zealand (Waghorn et al., 2006), little attention has been paid to the sustainability of anthelmintic practices in... Continued}, issn = {1176-5283}, author = {McAnulty RW and Gibbs SJ and Greer AW} } @conference {75890, title = {BRIEF COMMUNICATION: Phenotypic selection of cows for lactation persistency}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {136-138}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {Lactational persistency is the degree to which early lactation yield persists during the lactation season. Though this is a desired dairy performance trait, it has not been directly selected for in New Zealand dairy populations. In spring-calving pasture-fed cows, peak lactation is reached soon after calving and then declines by about 10\% per month (Davis et al., 2000) until the cows are... Continued}, issn = {1176-5283}, author = {Hickey SM and Singh K and Morris CA and Henderson HV and Molenaar AJ} } @conference {75879, title = {BRIEF COMMUNICATION: The effect of dam age and lamb birth rank on the growth rate, faecal egg count and onset of puberty of single and twin female offspring to 12 month of age}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {83-85}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {Breeding ewe lambs at eight to nine months of age has gained popularity on New Zealand sheep farms in recent years. This is predominantly because of the many production advantages it offers: greater net profits, increased number and weight of lambs produced per ewe productive lifetime, better use of spring herbage, early recognition of fertility potential, increased rates of genetic gain and... Continued}, issn = {1176-5283}, author = {Loureiro MFP and Paten AM and Asmad K and Pain SJ and Kenyon PR and Pomroy WE and Scott I and Blair HT} } @conference {75873, title = {BRIEF COMMUNICATION: The effects of dam nutrition during pregnancy on the postnatal growth and puberty attainment of ewe progeny}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {56-58}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {In New Zealand{\textquoteright}s pastoral sheep-production systems, feed can become limiting during winter, when breeding ewes are pregnant. Ewes are often restrictively fed during early-gestation (Kenyon \& Webby, 2007) to enable greater levels of nutrition in late-gestation. Many studies have demonstrated that dam nutrition during various stages of pregnancy can program the...}, issn = {1176-5283}, author = {Paten AM and Asmad K and Loureiro MFP and Kenyon PR and Pain SJ and Peterson SW and Pomroy WE and Scott I and Blair HT} } @conference {75874, title = {BRIEF COMMUNICATION: The effects of dam nutrition during pregnancy on the growth of male offspring}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {59-61}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {During pregnancy, nutritional status of the ewe is crucial because of its potential effect on fetal development, subsequent lamb survival and reproduction post-birth (Rhind et al., 2001). Manipulation of the progress of fetal development can affect the structure and physiology of adult offspring through the process of fetal programming (Barker et al., 1993). Epidemiological data... Continued }, issn = {1176-5283}, author = {Asmad K and Paten AM and Loureiro MFP and Kenyon PR and Pain SJ and Parkinson TJ and Pomroy WE and Scott I and Blair HT} } @conference {75906, title = {BRIEF COMMUNICATION: The effects of different forage types on lamb performance and meat quality}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {208-210}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {

Meat quality is made up of a number of traits, with colour at the point of purchase, being perceived as the main indicator of freshness. The traits of aroma, flavour, succulence, and texture influence the eating experience and the probability of repurchase. A number of factors influence meat quality traits, including environmental factors such as... Continued.

}, issn = {1176-5283}, author = {Campbell AW and Maclennan G and Judson HG and Lindsay S and Behrent MR and Mackie A and Kerslake JI} } @conference {75871, title = {BRIEF COMMUNICATION: The influence of a herb and legume sward on maternal behaviour and lamb colostrum intake and thermoregulation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {50-52}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {Nutrition of the ewe in late pregnancy is known to affect colostrum production, lamb live weight, survival to weaning (Kenyon \& Webby, 2007; Kerslake et al., 2009), and maternal behaviour (O{\textquoteright}Connor et al., 1985). Kenyon et al. (2010) reported that offering a mixed herb sward containing... Continued}, issn = {1176-5283}, author = {Hutton PG and Kenyon PR and Bedi MK and Kemp PD and Stafford KJ and West DM and Morris ST} } @conference {75872, title = {BRIEF COMMUNICATION: Voluntary food intake of pregnant and non-pregnant red deer hinds during the gestating period}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {53-55}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {Efficient venison production systems rely on maximum growth of deer calves before their first winter. This is facilitated by an early conception in March for an October/November calving so that the nutritional demands of lactating hinds and their offspring are better aligned with pasture growth and quality under New Zealand lowland farming conditions. However, Scott et al. (2008) have...}, issn = {1176-5283}, author = {Scott IC and Barrell GK and Asher GW and Yuan JV} } @conference {75895, title = {Can livestock production be increased without increasing greenhouse gas emissions?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {156-162}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {More efficient farming practices will increase livestock production without increasing greenhouse gas (GHG) emissions. GHG emissions of methane (CH4), nitrous oxide (N2O) and carbon dioxide (CO2) have always been part of agriculture, but national and international concern about global warming has focused research towards their mitigation. CH4 production represents a loss of about 9\% of metabolisable energy in feed, whilst N2O production represents a loss from excessive nitrogen (N) application. Mitigation should therefore provide benefits for farming by conserving dietary energy and reducing fertiliser costs. Unfortunately there are limited options for reducing CH4 loss. Nevertheless, by ensuring animals are productive and fertile and adopting management systems that ensure a high utilisation of feed grown, it is possible to lower CH4 emissions per unit of product. There are more opportunities for reducing N2O emissions, because these originate in large part from N fertiliser application, and more prudent use will lower costs, minimise nitrate leaching into waterways as well as lowering GHG emissions. Emissions per unit of product are termed emissions intensity. Application of current and new knowledge to agricultural systems will increase livestock production and lower emissions intensity whilst sustaining our ecosystem, but farmers will always need to address environmental issues.}, issn = {1176-5283}, author = {Waghorn GC} } @conference {75898, title = {The challenges of animal wintering from a sustainability perspective}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {172-175}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {Winter represents an important time for South Island dairy herds. The task of improving body condition of cows during winter poses a number of challenges in this environment. Under current forage crop based wintering systems, many cows fail to achieve body condition score targets and there is increased potential for nutrient leaching and the loss of soil structure and health. In addressing the poor cow performance and to minimize the environmental impact of current systems, farmers are looking to alternative wintering systems. Consequently off-pasture systems to manage feed supply and provide shelter in winter are becoming more common to remove the need for grazing forage crops and limit effluent discharges into the environment. While many farmers have viewed such systems as a solution to their wintering issues, rapid implementation and lack of readily available information on best practice management has resulted in sustainability issues unique to these new systems. This paper examines the challenges of wintering in the southern South Island and outlines how the dairy industry is working to provide sustainable options for the future.}, issn = {1176-5283}, author = {Dalley DE} } @conference {75892, title = {Continuing to increase productivity while maintaining our clean green image. Introductory remarks}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {149}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {An increase in intensive livestock farming can help our agricultural industry increase the production of more affordable food products. Unfortunately it can also have a negative impact on our environment and consequently the overall acceptance of our food products by the international consumer. To retain our position as leaders of premium quality agricultural food products, the New}, issn = {1176-5283}, author = {Kerslake JI} } @conference {75880, title = {Dairy goat production systems in Waikato, New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {86-91}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {Thirteen dairy goat farmers from the Waikato region of New Zealand were surveyed to describe and quantify the main features of their production systems. Twelve herds were maintained indoors and one herd was under grazing conditions, the latter farm was excluded from further analyses. All farms supplied milk to the Dairy Goat Cooperative (NZ) Ltd which produces milk powder for export. A total of 11 breed groups were identified. Out of the total milking does, Saanen was 88\%, Toggenburg x Saanen 8\%, Toggenburg 2\% and others 2\%. The average herd comprised 20\% replacement kids, 17\% does between 7 to 12 months-of-age, 59\% does 1 to 10 years-old and 4\% bucks. Culling of milking does was due to low production (35\%), poor fertility (14\%), leg problems (6\%), mastitis (6\%) and other reasons (13\%), while 27\% died between 1 to 10 years-old. Daily milk yield {\textpm} standard deviation per doe and per hectare were 2.8 {\textpm} 0.2 and 34.0 {\textpm} 3.7 kg respectively; while milk-solids were 0.32 {\textpm} 0.02 kg/doe and 4.10 {\textpm} 0.43 kg/ha, respectively, over a standardised 270 day lactation. Expenses were mainly feed concentrates (21.5\%), dairy wages (20.3\%), overheads (14.0\%), family labour (14.5\%) and other expenses (21.5\%). The rates of return on investment were 10.2\% and 10.7\%, per milking doe and per hectare, respectively.}, issn = {1176-5283}, author = {Solis-ramirez J and Lopez-Villalobos N and Blair HT} } @conference {75889, title = {An economic appraisal of sex-sorted semen in New Zealand dairy herds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {131-135}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {An economic appraisal was undertaken of female enriched dairy semen in New Zealand commercial dairy cattle. Artificial insemination (AI) scenarios were evaluated in cows (C) and yearling heifers (H) with normal (N-) or sex-sorted semen (S-) with a female enrichment ratio leading to 75\% (S75) or 90\% (S90) heifer calves at birth. In-calf rates with S-semen were 0.75 of normal. Scenarios examined were: cows inseminated with N-semen and yearling heifers naturally mated (CN); cows inseminated with S-semen (CS75 and CS90); cows and yearling heifers inseminated with N-semen (CN-HN); and cows inseminated with N-semen and yearling heifers with S-semen (CN-HS75) and (CN-HS90). These scenarios required 29, 24, 19, 20, 19, and 17 days of AI in cows, respectively. S-semen reduced six-week in-calf rate and final calving rate. The total costs, including reproduction losses, semen and insemination, of producing a four-day old AI heifer replacement calf in a herd of 400 milking cows were $70, $262, $292, $69, $129 and $143. Maximum genetic gain in the milking herd is achieved using S90 semen in the highest genetic merit cows, although this is uneconomic at current semen prices. S-semen has a limited role in New Zealand dairy herds.}, issn = {1176-5283}, author = {McMillan WH and Newman MG} } @conference {75864, title = {Economic evaluation of management strategies for a model Waikato farm to achieve a herd average body condition score of 5.0 at calving}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {17-22}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {Industry advisers advocate a herd average body condition score (BCS) of 5 at calving to optimise profitability and system sustainability. However, the full value and cost of achieving the industry target has not been evaluated. Using the Farmax Dairy Pro model, the value of increasing the herd average BCS at calving from 4.0 to 5.0 was evaluated. A representative Waikato farm with a single dry off date in mid-May, with a herd average BCS of 4.0 at calving was modelled as the Base scenario. The profitability of seven alternative scenarios that achieved average herd BCS of 5.0 at calving were examined. Strategies that traded off autumn production to attain target BCS maintained a similar operating profit (OP) of -$46/ha to $3/ha, relative to the Base scenario. Partial season once-a-day milking increased OP by $220/ha to $269/ha, as long lactations and BCS targets were able to be achieved while reducing operating expenses. Additional supplements fed to dry cows to achieve target BCS increased OP by $43/ha. Additional mid-late lactation feeding increased OP by $139/ha to $269/ha, but only effected BCS by 0.15 units during lactation. These simulations indicate there is value in achieving recommended BCS targets, with multiple profitable strategies to do so.}, issn = {1176-5283}, author = {Douglas RJ and Bryant JR and Hedley P and Smeaton DC and Brazendale R and Roche JR} } @conference {75865, title = {The effect of carbohydrate type on milk and milk component yields in early lactation dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {23-27}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {Providing additional energy to dairy cows in early lactation can increase energy intake, and improve production; however, different energy types may elicit different types of responses. The current study assessed the effect of supplementary feeding of starch, fibre, or sugar on milk and milk component yield. Sixty-eight dairy cows, due to calve over a 21-day period, were randomly assigned to one of four treatments at parturition (n = 17). Treatments consisted of a pasture-only control and pasture with starch, fibre or sugar based supplements. Supplements were formulated using the Cornell Net Carbohydrate and Protein System v6.1 and fed at an isoenergetic rate to supply sufficient metabolisable energy and protein to support a target of 30 kg of potential milk production, assuming cows would consume 13 kg of pasture DM/day; 11 MJ ME/kg DM. The study ran for eight weeks, and data were analysed on a week of lactation basis. Relative to the control, milk and milk protein yields were higher for the starch- and fibre-based supplements, but similar for the sugar (P <0.01). Protein yields were highest in cows supplemented with starch (P <0.001), while fat yields were numerically highest in cows supplemented with fibre. These data confirm that the form of carbohydrate fed affects the types of responses seen when supplementing concentrates in early lactation.}, issn = {1176-5283}, author = {Higgs RJ and Sheahan AJ and Mandok K and Roche JR} } @conference {75928, title = {Effect of condensed tannins from Pinus radiata bark on Trichostrongylus colubriformis larvae and adult worms in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {304-308}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {A trial was undertaken to investigate the effect of condensed tannins (CT) extracted from pine (Pinus radiata) bark on gastrointestinal (GI) nematodes. Gastrointestinal parasitism is a significant cost to the sheep industry affecting health and productivity. Previous research has shown CT from some forage species can inhibit parasite egg hatching, larval development and reduce worm numbers in the GI tract. However, the forages containing CT tend to be less productive than ryegrass pasture, so this research investigated pine bark extract (PBE) which contains CT and is abundant in New Zealand, on Trichostrongylus colubriformis nematodes. In the in vitro incubations, 150 {\textmu}g CT/ml prevented larval development and halved egg hatching. Effects of CT in vivo (35g/day) were evaluated using 12 wether sheep, fitted with abomasal cannulae and infected with T. colubriformis larvae. The sheep were either drenched at six hourly intervals or the PBE was infused into the abomasum over four days. Neither treatment affected faecal egg count (1,700/g faeces), egg hatching or development of eggs to L3 larvae. Lambs were slaughtered after four days of treatment. Nematode numbers were similar for all treatments (average 21,100/animal). Despite inhibitory effects on hatching and development in vitro, PBE had no anthelmintic benefits for the sheep and may reduce intakes.}, issn = {1176-5283}, author = {Chan J and Waghorn GC and Molan AL and Brookes IM} } @conference {75905, title = {Effect of lactation stage and breed on the concentration of unsaturated fatty acids in milkfat of New Zealand dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {203-207}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {Milkfat composition influences the nutritional value and manufacturing characteristics of milk. This research studied the influence of: 1) stage of lactation on the concentration of unsaturated fatty acids (UFA) in milkfat of Holstein-Friesian, Jersey and Crossbred cows, 2) segregation of cows according to their UFA concentration in milkfat. The concentration of UFA in milkfat was predicted with a calibration equation using Fourier transform infrared spectroscopy. The data (21,757 test-day records) were analysed using a mixed model with a third-order orthogonal polynomial. In the three breeds studied, after early lactation the concentration of UFA in milkfat decreased steadily as the lactation progressed, but in Holstein-Friesian cows it increased slightly at the end of lactation. Throughout lactation, Holstein-Friesian cows produced milkfat with a higher concentration of UFA than Jersey and Crossbred cows. In each herd, cows were split into a high and a low group according to the average UFA concentration of the herd. The high UFA group had higher (P <0.001) milk yield, but lower (P <0.001) yields and concentrations of fat and protein than the low UFA group. This study indicates that concentration of UFA in milkfat is affected by breed and stage of lactation in New Zealand dairy cattle.}, issn = {1176-5283}, author = {Silva-Villacorta D and Lopez-Villalobos N and Blair HT and Hickson RE and Spelman RJ and Melis J and Davis SR and Berry SDK and Lehnert K and Snell RG} } @conference {75868, title = {Effect of milking frequency and nutrition in early lactation on milk production and body condition in grazing dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {37-41}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {Multiparous Holstein-Friesian cows (n = 120), grazing pasture and milked twice-daily (2X) from calving until ~35 days in milk, were allocated to one of four treatments. Treatments consisted of 2X or once-daily milking (1X), and UnRes (15 kg dry matter (DM)/cow/day) or Res (9 kg DM/cow/day) pasture intake for three weeks. Following treatment, all animals were milked 2X and offered pasture (residuals of 1,600kg DM/hectare) for 20 weeks. During the treatment period (Weeks 1-3), yields of milk, fat, protein and lactose decreased with reduced milking frequency and feeding level. Interactions existed for milk, protein and lactose yields and the decrease due to 1X milking was greater in the UnRes than Res cows. During the post-treatment periods (Weeks 4-12 and Weeks 13-23) no interactions were present. Restricted cows produced less milk, fat, protein and lactose compared with UnRes cows during Weeks 4-12, but no difference existed during Weeks 13-23. During Weeks 4-12, cows milked 1X produced less milk, fat, protein and lactose than those milked 2X and these differences remained during Weeks 13-23. During the treatment period, body condition score was less in Res than UnRes cows, however there was no effect of milking frequency on body condition score. Neither feeding level nor milking frequency altered post-partum anoestrus interval.}, issn = {1176-5283}, author = {Kay JK and Phyn CVC and Rius AG and Morgan SR and Grala TM and Roche JR} } @conference {75866, title = {Effect of pre-grazing herbage mass on grazing behaviour, grass dry matter intake and milk production of dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {28-32}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {Identifying the optimum level of pre-grazing herbage mass (HM) across the grazing season is critical to maximising dry matter intake (DMI) and milk production from dairy cows. From 27 April to 17 October 2010, in Moorepark, Ireland, 45 Holstein-Friesian dairy cows (mean calving date 23 March 2010) were randomly assigned to Low (L), Medium (M) or High (H) pre-grazing HM treatments (targets 800, 1,500 or 2,200 kg DM/ha, above 4 cm, respectively) using perennial ryegrass-based pastures. Pre-grazing HM was determined twice weekly. Grazing behaviour was measured once and herbage DMI twice. Milk production was recorded daily. The experiment was divided into Period 1 (Mid-season; 27 April to 25 July) and Period 2 (Autumn; 26 July to 17 October). In the autumn, cows on L HM swards grazed for 90 minutes more and had 15\% more grazing bites on a daily basis than did the cows on the other treatments. Cows grazing M HM swards tended to have highest DMI (L-15.2, M-16.5, H-15.7 kg DM/cow/day); while cows grazing H HM swards tended to have lowest milksolids yields (L-1.43, M-1.43, H-1.31 kg milksolids/cow/day). Pre-grazing HM levels of 2,200 kg DM/ha may impair DMI and milksolids production per cow, most likely due to decreased sward quality.}, issn = {1176-5283}, author = {Tu{\~n}on G and Lopez-Villalobos N and Kemp PD and Kennedy E and Hennessy D and O{\textquoteright}donovan M} } @conference {75925, title = {Effect of sub-clinical uterine infection on plasma amino acid concentrations in early lactation dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {291-295}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {This study examined the effect of sub-clinical endometritis (scEndo) in early lactation on plasma amino acid (AA) concentrations of dairy cattle (n = 46). On D21 and D42 postpartum cows were classified as having scEndo or Clean based on uterine cytology; >18\% polymorphonuclear (PMN) cells amongst uterine nucleated cells. On D21 and D42, 35\% and 7\% of cows respectively were classified as having scEndo, with a large proportion of scEndo cows having self-resolved the infection by D42. Plasma serine concentrations were higher (P <0.03) in scEndo compared to Clean cows irrespective of day postpartum. Independent of uterine status, three AA altered (P <0.05) in concentration between D21 and D42. The effect of change in uterine status from D21 to D42 resulted in decreased (P =0.05) concentrations of three AA in cows that resolved infection. The use of a lower cut-off to define scEndo (4\% vs 18\%PMN) identified four AA, instead of three AA at 18\% that differed over time. Thus, during the early postpartum period, the concentrations of a number of AA change (P <0.05) irrespective of uterine health. However, scEndo is associated with an increase in plasma serine and a decrease in the concentration of several AA when a uterine infection is resolved.}, issn = {1176-5283}, author = {Lopdell T and Berg MC and Green MP and Back PJ} } @conference {75870, title = {Effect of temporary alterations to milking frequency during the early post-partum period on milk production and body condition score in grazing dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {45-49}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {This study investigated the immediate and long-term effects of temporary alterations to milking frequency post-partum in grazing cows. Multiparous Holstein-Friesian cows (n = 150) were assigned to one of five groups at calving: milked twice daily (2X, Control), or either once daily (1X) or thrice daily (3X) for three or six weeks, and 2X thereafter. During Weeks 1-6 post-calving, 1X for six weeks resulted in greater decreases in milk, fat, protein and lactose yields (P <0.05) relative to 2X than 1X for three weeks. Furthermore, 1X for three or six weeks reduced fat, protein and lactose yields (P <0.05), and tended to reduce milk yields (P = 0.08), for the remainder of lactation (Weeks 8-32). Body condition was greater for 1X cows at Weeks 6 and 8 (P <0.05) and tended to be greater during Weeks 8-32 (P = 0.09). Milking 3X for three or six weeks increased milk yield (P <0.05) relative to 2X during Weeks 1-6 and milk yields were numerically greater during Weeks 8-32 (P = 0.17); however, fat and protein yields were not affected. Once-daily milking for three or six weeks postcalving had lactation-long negative effects on milk production, whereas 3X increased milk yield but did not result in short- or long-term benefits in fat and protein yields.}, issn = {1176-5283}, author = {Phyn CVC and Kay JK and Rius AG and Morgan SR and Roach CS and Grala TM and Roche JR} } @conference {75862, title = {The effect of three techniques of rumen pH assessment on measured pH of rumen fluid and digesta in an in vitro artificial rumen system}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {9-12}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {Rumen pH assessment by three techniques was compared using an in vitro, artificial rumen system. Rumen digesta from dairy cows fed kale, fodder beet or ryegrass and clover pasture was used in an in vitro artificial rumen system. The digesta pH was measured by obtaining rumen fluid by centesis, by direct probe insertion, and by removal and filtration of fluid through cloth. This was done at different time intervals and at different heights from the base of the artificial rumen. There were significant differences in mean diet group pH. There was a significant difference between mean pH of all three techniques at the first time interval, and similarly between centesis and both the other techniques at the second and third time intervals. There was no significant difference between collection site height at any time interval. For dairy cows fed these forage diets, the technique of pH assessment of in vitro rumen digesta significantly influenced the pH measured, with centesis associated with higher mean pH than direct probe assessment. Given the importance of accurate rumen pH assessment, and the implications of differences between rumen fluid and rumen digesta pH in forage based ruminants, further research using the methodology with in vivo models is warranted.}, issn = {1176-5283}, author = {Broomfield AM and Gibbs SJ} } @conference {75929, title = {Effect of wine lees on faecal egg count and lamb performance}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {309-313}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {The potential anti-parasitic of lees from several wine varieties was investigated using an in vitro anthelmintic assay using Haemonchus contortus eggs. The most effective lees variety was further investigated in lambs in two trials. In Trial 1, 60 sheep was pasture grazed as one mob and allocated to one of three groups (n = 20): water drenched; drenched with the anthelmintic Matrix, and daily drenched with 100 mL/animal Pinot noir (PN) lees. In Trial 2, 80 lambs were grazed as one mob and assigned to four treatments (n = 20): Pasture only (Control); Pasture plus lucerne pellets; Pasture, lucerne pellets and drenched with Matrix; Pasture, lucerne pellets and wine lees. In both trials, fecal egg count (FEC) and live weight were measured weekly. PN lees displayed positive in-vitro anthelmintic activity. In Trial 1, lees provided insignificant (7\%) increase in cumulative liveweight gain relative to Control (P >0.05). In Trial 2, the overall mean daily gain (g/day) was not different with lees feeding but slight increased (26.6\%) following drenching with Matrix (P >0.05). Lees, at the concentration used in this trial of 460 mg tannin/day/animal, did not offer a reliable stand-alone anthelmintic control.}, issn = {1176-5283}, author = {Bekhit AED and Richardson A and Grant C} } @conference {75908, title = {Efficiency, cheese yield and carbon emissions of Holstein-Friesian, Jersey and crossbred cows: an overview}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {214-218}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {This paper provides an overview on differences between Holstein-Friesian (HF), Jersey (J) and crossbred cows, for feed conversion efficiency (FCE), dry matter intake (DMI), cheese yield and carbon emissions. It was found that J cows have significantly higher DMI per kilogram of live weight (LWT) compared to HF and F1 HFxJ cows (3.64, 3.81 and 3.23 g DMI/kg LWT, respectively). A higher DMI per kilogram of LWT can result in more energy available for milk production, assuming that the maintenance requirements per unit of LWT are equal between the breeds. Estimates of FCE measured as grams of milksolids (milkfat plus milk protein) per kilogram of DMI were higher in J than HF cows (112 vs 97 g MS/kg DMI) in the reviewed papers. For grazing cows, a higher proportion of feed consumed is converted into milk production than used to cover maintenance energy requirements in J cows. This may result in lower greenhouse gas emission intensity from J than HF cows. Opportunities for the utilisation of breed differences to increase FCE and reduce carbon footprint and increase overall farm profitability in grazing dairy systems requires further farming system research to elucidate the relative efficiencies of the most common dairy breeds.}, issn = {1176-5283}, author = {Sneddon NW and Lopez-Villalobos N and Baudracco J} } @conference {75923, title = {Feeding behaviour differs between dairy calves selected for divergent feed conversion efficiency}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {281-285}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {Feeding behaviour and efficiency of feed utilisation, measured as residual feed intake (RFI; defined as actual feed intake minus predicted feed required), were measured in dairy calves aged six to seven months-old, and associations between the two variables were determined. The intake, feeding behaviour, and live weight of 219 female Holstein-Friesian calves were recorded for 46 days. Animals were housed in an outdoor facility comprising 28 pens, each with a single-access feeder containing dried, cubed lucerne. Efficient animals were associated with lower intakes (r{\texttwosuperior} = 0.29), fewer meals/day (r{\texttwosuperior} = 0.05), less time spent eating/day (r{\texttwosuperior} = 0.03), and slower eating rates (r{\texttwosuperior} = 0.03). The 30 most efficient animals consumed less (mean {\textpm} standard error of difference; 6.15 vs 7.46 {\textpm} 0.20 kg cubes/day), had fewer meals (4.03 vs 4.85 {\textpm} 0.29 meals/day), and spent less time feeding (2.68 vs 2.93 {\textpm} 0.11 hours/day) compared to the 30 least efficient animals (all P <0.05). Rate of liveweight gain, eating rate, amount eaten per meal, and meal duration did not differ between the 30 most efficient and 30 least efficient animals (P >0.05). In conclusion, differences in feeding behaviour were found between dairy calves selected for divergence in efficiency which may have implications for their management.}, issn = {1176-5283}, author = {Green TC and Waghorn GC and Beausoleil NJ and MacDonald KA} } @conference {75863, title = {Fenbendazole as a possible marker of supplement intake in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {13-16}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {This study aimed to determine the dose-dependent relationship between oral doses of fenbendazole (FBZ) and the plasma concentration of its metabolites, oxfendazole (OFZ) and fenbendazole-sulphone (SUL). Twenty five, two year-old, Merino wethers were equally allocated to treatment groups of different oral dose rates of FBZ (n = 5) and housed in individual pens. Treatment groups were designed to provide daily oral doses of 0.25, 0.5, 1.0, 2.0 and 4.0 mg/kg live weight of FBZ, suspended in water, for six days. Blood samples were collected from each animal at 48, 96, and 144 hours after administration of FBZ. Plasma was equally combined within each animal and analysed to determine concentrations of FBZ, OFZ and SUL. There was a positive linear relationship between FBZ dose rate and FBZ metabolite plasma concentration (R2 = 0.991, P <0.001). Mean separation of plasma concentrations indicated significant differences (P <0.05) between treatments designed to provide 1.0, 2.0 or 4.0 mg/kg/day FBZ. Plasma concentrations of animals which received 0.25 or 0.50 mg/kg/day FBZ were significantly lower than other treatments (P <0.05). The results from this experiment provide preliminary support for the investigation of FBZ as a useful marker to estimate supplement intake of grazing animals.}, issn = {1176-5283}, author = {Fishpool FJ and Kahn LP and Tucker DJ and Nolan JV and Leng RA} } @conference {75882, title = {Flexibility and climate risk management in high stocking rate dryland sheep farming systems}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {96-102}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {A trial unit of 87.8 ha with conventional grass-based pastures and one of 85.1 ha with high legume-content pastures were used to investigate the impact of climate-risk management strategies on production and profitability of dryland sheep farming systems. The target stocking rate of both units was 14 stock units (SU)/ha, which is markedly higher than the regional monitor farm at 8.8 SU/ha. Information on the feed supply and animal feed requirement of the two units for 2008/09 and 2009/10 are presented, along with differences in weather patterns, soils moisture, climate-risk responses used, and stock sales between the two years. Results from the grass-based unit indicated that the flexible livestock policies used and climate-risk management responses imposed were able to increase farm profitability and reduce its variability between years in comparison to the local Ministry of Agriculture and Forestry monitor farm model. However, the same was not true for the high legume-content unit, which encountered a number of problems with high lamb deaths and poor lamb finishing in 2008/09. Soil moisture level in the top 25 cm proved to be a simple, inexpensive and effective indicator for making appropriate farm management decisions in response to changes in the climate.}, issn = {1176-5283}, author = {Bywater AC and Logan CM and Edwards GR} } @conference {75899, title = {The future for animal welfare science: Is there a clear direction or are we just responding to issues? Introductory remarks.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {178}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {

Animal welfare has emerged as a major factor that must be considered in order to maintain access for New Zealand{\textquoteright}s pastoral products into overseas markets. Increasing consumer interest and concern is placing pressure on our animal-based agricultural industries to provide "welfare friendly" products. Although, on the positive side, due to our pasture-based systems compared to indoor systems overseas, New Zealand is... Continued

}, issn = {1176-5283}, author = {Stewart M} } @conference {75888, title = {Genetic analysis of incidence of recorded clinical lameness in New Zealand dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {126-130}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {Herd records from 76,357 cows, collected during the 2005/06 to 2008/09 milking seasons from 155 herds in the Livestock Improvement Corporation (LIC) young sire progeny test scheme, were used to estimate genetic parameters and breed effects for incidence of recorded clinical lameness (RCL) in Holstein-Friesian, Jersey and crossbred dairy cattle. RCL was coded "1" for cows that presented at least one event of RCL at any day during the season and "0" for cows without RCL. Genetic parameters were estimated with a repeatability animal model across breeds. The average incidence of RCL per herd was 6.3\% and ranged from 2\% to 34\%. Jersey cows had significantly (P <0.05) lower incidence (6.0\%) than Friesian cows (6.8\%) but similar to crossbred cows (6.1\%). The heritability estimate for incidence of RCL was 0.016 {\textpm} 0.003 (standard error) while the repeatability was 0.071 {\textpm} 0.005. Sire estimated breeding values for RCL ranged between -5 and 8\% with Jersey sires showing the lowest values. These results suggest that selection for resistance to lameness will result in a low rate of genetic gain but using Jersey sires can be an alternative to increase genetic resistance to lameness in New Zealand dairy cattle.}, issn = {1176-5283}, author = {Chawala AR and Lopez-Villalobos N and Margerison JK and Spelman RJ} } @conference {75916, title = {Genetic and phenotypic relationships between flystrike indicator traits in a stud Merino flock}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {251-256}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {

Increasing breech wrinkles, breech cover and dags increase flystrike susceptibility of Merino sheep. Urine stain has been implicated in flystrike, although there is a paucity of data. At tail docking in 2007, 2008 and 2009 on a property breeding Merino rams, breech wrinkle (1 to 5) was scored on 238, 202 and 337 lambs that were the progeny of 12, 9 and 9 sires respectively. Dag score (0 to 5), urine stain (0 to 5) and breech cover (1 to 5) were scored at 100 days of age. Breech wrinkle score (h{\texttwosuperior} = 0.51 {\textpm} 0.11) and breech cover (h{\texttwosuperior} = 0.27 {\textpm} 0.08) were heritable, and phenotypically (0.16 {\textpm} 0.04, P \<0.05) and genetically correlated (0.77 {\textpm} 0.14, P \<0.05). Dag and urine stain scores were skewed towards low scores and the heritability estimates for these traits were low (h{\texttwosuperior} = 0.08 {\textpm} 0.07 and 0.04 {\textpm} 0.06 respectively). Yearling clean fleece weight was heritable (h{\texttwosuperior} = 0.28 {\textpm} 0.13) and genetically correlated with breech cover (-0.62 {\textpm} 0.26, P \<0.05). There was no evidence of flystrike during the investigation, but there was potential to decrease susceptibility by decreasing breech cover and breech wrinkles in this flock.

}, issn = {1176-5283}, author = {Scobie DR and Hickey SM and Maslen DP and Black GM} } @conference {75902, title = {Heat stress in farm animals}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {185-189}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {Heat stress affects production and welfare in farm animals. In warm weather animals will change their behaviour in order to cool down, for example by seeking shade or other cooler microclimates, and by altering activity patterns, body postures and feed intake. In addition to behavioural changes, physiological mechanisms will occur, such as increased respiration and body temperature. There is consistent evidence that the reduced productivity in association with heat stress can be alleviated by providing different types of cooling. However, more research is needed in order to explore how to best cool farm animals and appropriate cost benefit analyses of providing different types of cooling in New Zealand conditions needs to be carried out to improve profitability and welfare. Animals change their behaviour before changes in production can be detected, therefore animal behaviour can provide insight into when and how to cool animals.}, issn = {1176-5283}, author = {Sch{\"u}tz KE} } @conference {75893, title = {The importance of sustainable food production for our markets}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {149-152}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {New Zealand market advantage is at the "top-end" of value, in the production of sustainable, superior quality, highly valued protein. Enhancing our image as the "garden of the pacific", will lead to greater opportunities for economic growth and a prosperous red meat industry, while at least maintaining, if not improving, our natural resources. This paper discusses what sustainable food production means and identifies some of the expectations of our international markets. The paper also briefly describes how Alliance Group Limited is responding to improving sustainable food production. Strategies outlined include improving farm practices, processing capabilities and improving quantity and quality of product.}, issn = {1176-5283}, author = {Brown M and Butler D} } @conference {75911, title = {In vitro digestion of ryegrasses harvested in the morning and afternoon to manipulate water soluble carbohydrate concentration}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {229-233}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {The concentration of water soluble carbohydrate (WSC) increases during the day and the difference between morning and afternoon is greater and more consistent than the difference between cultivars. An in vitro batch culture system was used to compare the fermentation of ryegrass cultivars that differed in WSC, after harvesting samples in the morning (08:00 h) and afternoon (16:00 h). Bottles were placed in a shaking incubator at 39{\textdegree}C and removed at 0, 2, 4, 6, 8, 12 and 24 hours to measure pH and concentrations of ammonia and volatile fatty acids (VFA). Ryegrasses harvested in the afternoon had 81-114 g/kg dry matter more WSC, 3-12 g/kg dry matter less neutral detergent fibre and 14-25 g/kg DM less crude protein than morning samples. Compared to morning harvested ryegrass cultivars, afternoon harvested ryegrass cultivars had the lowest yields of VFA. Afternoon-harvested ryegrass cultivars, especially high sugar ryegrass, were rapidly fermented and after four hours the pH of high sugar ryegrass decreased to less than 5.8, which has been reported to cause suboptimal fibre digestion. It may be possible to manipulate the WSC concentration of a pasture diet by altering grazing management practices. Further research is required to characterise the optimum concentration of WSC for efficient rumen fermentation.}, issn = {1176-5283}, author = {Burke D and Pacheco JL and Cosgrove GP} } @conference {75876, title = {The incidence of goitre in newborn lambs from ewes fed fodder radish, rape or Italian ryegrass with or without iodine supplementation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {66-70}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {Brassicas are an important forage species on many New Zealand sheep farms. However, glucosinolates present in some brassicas can cause iodine deficiency in lambs when pregnant ewes are fed such crops during gestation. To investigate the effect of differences in glucosinolate profile of fodder radish and a brassica on ewe thyroid function and incidence of goitre in lambs born to ewes grazing these crops during pregnancy, a 3 x 2 factorial study utilising three diets (Italian ryegrass, fodder radish, rape) and two rates of iodine (I) supplementation (with, without) was conducted. Thyroid hormone (T3, T4) response to a thyroid releasing factor (TRF) challenge in ewes and incidence of goitre in newborn lambs was determined. A mild goitre, based on thyroid weight:lamb weight ratio (g/kg) of >0.4, was recorded only in newborn lambs from ewes fed rape and the incidence was higher (75\% vs 11\%) in those without I supplementation. Pregnant ewes grazing radish or rape had the lowest T3 and T4 responses to TRF, except in the case of T4 where there had been I supplementation. Differences in glucosinolate content and composition may explain the differing results for sheep fed radish or rape.}, issn = {1176-5283}, author = {Judson HG and Barrell GK} } @conference {75930, title = {Legend session: Forage secondary compounds; past, present and future}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {314-321}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {Forages contain plant secondary compounds. These are primarily produced to protect the plant from attack by micro-organism, insects and herbivores. Research during the last 40 years has produced an insight into the biochemistry, metabolism and interaction of these compounds, specifically the unique amino acid S-methyl cysteine sulphoxide (SMCO) and condensed tannins (CT). Both occur within forage consumed by farmed livestock. SCMO induces anaemia in herbivores. Through plant breeding and effective management brassica crops can now be fed to livestock as a supplement without restricting growth rate. A wide range of plants contain CT. CT have been shown to have the capacity to bind to soluble proteins in the rumen enabling increased absorption of essential amino acids from the small intestine. This benefits body growth, milk production, wool growth and ovulation rate. CT have also been shown to have a direct effect on gastrointestinal parasites inhibiting their growth and fecundity, particularly in sheep. As a result of this detailed research we are now able to exploit the unique attributes of some plant secondary compounds and use them to our advantage to benefit animal production and the performance of our farmed livestock. Ways in which we able to do this are discussed.}, issn = {1176-5283}, author = {Barry TN} } @conference {75891, title = {Life cycle assessment - a tool for evaluating resource and environmental efficiency of agricultural products and systems from pasture to plate}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {139-148}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {Life cycle assessment is a useful tool to evaluate the resource use and environmental efficiency of agricultural systems and products, and to account for these along the whole supply chain or life cycle. Its application to agricultural products is most evident with carbon footprinting, where it is being used at industry, policy and consumer levels including for eco-labelling. Research in dairy, sheep and beef systems has shown that the farm-related stage is the main contributor to product carbon footprints and that in New Zealand they have been gradually reducing over time with increasing productivity. While the carbon footprints of New Zealand pastoral agricultural products are generally low compared to overseas products, there can be up to a two-fold variation between individual farms, illustrating the potential for on-farm efficiency gains. Fossil fuel and total energy use on New Zealand farms are low compared to overseas but are increasing with greater use of high energy-demanding nitrogen fertiliser. Water footprinting is likely to become an important resource indicator with the global focus on fresh-water scarcity. A key benefit of life cycle assessment is that it enables evaluation of the potential impacts of products on multiple resource use and environmental indicators for system optimisation.}, issn = {1176-5283}, author = {Ledgard SF and Lieffering M and Zonderland-thomassen MA and Boyes M} } @conference {75914, title = {Methane output and rumen microbiota in dairy cows in response to long-term supplementation with linseed or rapeseed of grass silage- or pasture-based diets}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {243-247}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {The long-term (>12 months) effect of fat supplementation on methane (CH4) output and rumen microbiota was measured in dairy cows. Twenty lactating dairy cows were fed indoor with grass silage/hay (Period 1), then outdoor with pasture-based diets (Period 2), and allocated to three dietary treatments for two consecutive entire lactations. Diets were not supplemented (C) or supplemented with 2-3\% dry matter of extruded linseed (EL) or extruded rapeseed (ER). Individual intake, milk and CH4 production (sulphur hexafluoride tracer technique) were measured on five consecutive days in both periods. Rumen pH, volatile fatty acid (VFA) concentrations and microbial numbers were measured on rumen fluid samples collected before feeding. For both periods, CH4 yield (g/kg dry matter intake) was lower for EL (-15\%; P <0.001), and numerically higher for ER (+14\%) compared to C. The unexpected effect of ER on CH4 emissions remains difficult to explain. Measured as g/kg fat corrected milk, CH4 output remained lower for EL (-26\%, P <0.05) than for C and ER, for both periods. Diet EL did not modify rumen VFA profiles and microbial numbers compared to C. Our work highlights the long term efficacy of EL supplementation of grass-based diets as a CH4 mitigation option.}, issn = {1176-5283}, author = {Martin C and Pomi{\`e}s D and Ferlay A and Rochette Y and Martin B and Chilliard Y and Morgavi DP and Doreau M} } @conference {75897, title = {Modelling farm management scenarios that illustrate opportunities farmers have to reduce greenhouse gas emissions while maintaining profitability}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {167-1"71}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {Farmer focus groups have been involved in a range of learning exercises and farm system modelling exercises to determine the effect that alternative farm management scenarios would have on greenhouse gas (GHG) emission profiles on-farm. Annual GHG emissions from the current livestock farming policies for the sheep and beef property were estimated to be 4.91 tonnes of carbon dioxide equivalents per hectare (t CO2-e/ha) or 14.3 kg CO2-e per kg of meat and fibre produced. All of the alternative farm management options had a small impact on total GHG emissions, ranging from a reduction of 0.67 t CO2-e/ha to an increase in 0.42 t CO2-e/ha (-13\% and + 8\% of the whole farm emissions per hectare, respectively). Most exposed the business to greater risk due to market and climate variability. The Canterbury dairy farm annual GHG emissions from the current farm were estimated to be 13.1 t CO2-e/ha or 9.9 kg CO2-e per kg of milk solids. Across the mitigation scenarios investigated total GHG emissions were up to 14\% lower than the baseline farm while emissions intensity ranged from 33\% higher to 9\% lower than the baseline farm. Opportunities which decreased emissions intensity and increased profit were identified; these require consideration of multiple risks around climate and market variability.}, issn = {1176-5283}, author = {Dynes RA and Smeaton DC and Rhodes AP and Fraser TJ and Brown MA} } @conference {75903, title = {Painful husbandry procedures and methods of alleviation: a review}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {189-194}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {Painful husbandry procedures are routinely performed on farms in New Zealand for various reasons. Tail docking is routinely carried out on sheep to prevent flystrike and on pigs to prevent tail biting. In some countries this procedure is still performed on dairy cows to improve udder hygiene and worker comfort. Castration is commonly performed on lambs and calves to reduce aggressive and sexual behaviours, prevent unwanted breeding, and modify carcass characteristics. Dehorning is performed on cattle to reduce the risk of injury to stock people and other animals and antler removal in deer is carried out for commercial reasons. All of these procedures cause behavioural and physiological changes indicative of pain, but are commonly performed without pain relief on farms. This review will cover the rationale and the behavioural and physiological responses caused by these common husbandry procedures. Possible methods of pain relief or alternative strategies to these procedures will then be discussed as well as the implications for New Zealand and where future research needs to be focussed.}, issn = {1176-5283}, author = {Sutherland MA} } @conference {75883, title = {Pasture growth and quality, and lamb growth rates in high stocking rate dryland sheep farming systems}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {103-108}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {Pasture growth and quality, and lamb growth rates were measured on a conventional grass based trial unit of 87.8 ha and a high legume unit of 85.1 ha, established to investigate climate-risk management strategies within high stocking rate dryland sheep farming systems. There was no difference between the units in total pasture production with a pasture utilization of 71.7\% and 74.3\% on the grass and legume units, respectively. Metabolisable energy values remained close to, or above, the target values throughout the growing season. Preweaning lamb growth rates averaged 304 g/day on both units. There were significant differences between singles (342 g/day), twins (300 g/day) and triplets (254 g/day) and between lambs from first cycle (294 g/day) and main mob ewes (315 g/day). There were some differences in lamb growth rates between different pastures types but these were not consistent between years. Post-weaning growth rates averaged 137 g/day with significant differences attributable to litter size, mob and year. Growth from birth to sale averaged 295 g/day, slightly less than the target of 300 g/day. Thus high lamb growth rates are possible on a range of pasture types on dryland at low pasture covers of high quality.}, issn = {1176-5283}, author = {Bywater AC and Logan CM and Edwards GR and Sedcole JR} } @conference {75924, title = {Physical and physiological factors associated with twin- and triplet-born lamb heat production at 24 to 36 hours of age}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {286-290}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {This study attempted to identify physical and physiological factors of twin- and triplet born lambs within the first 24 to 36 hours of life which are associated with maximum heat production on a per lamb basis (W/lamb) and a per kg of birth weight basis (W/kg). Multiple regression analyses revealed that lamb birth weight accounted for 34 percent of the variation in maximum heat production on a per lamb basis (P <0.001), whereas, inclusion of plasma non-esterified fatty acids (NEFA; P <0.01), tri-iodothyronine (T3; P <0.05) and glucose concentrations at 24 to 36 hours of age (P <0.05) increased the accountability to 59 percent. Multiple regression analyses also revealed that plasma NEFA concentrations at 24 to 36 hours of age accounted for 15 percent of the variation in maximum heat production on a per kg of birth weight basis (P <0.01), whereas, inclusion of plasma T3 at 24 to 36 hours of age increased the accountability to 22 percent (P <0.05). Overall these results suggest that having greater lamb birth weights, plasma thyroid hormone, glucose and NEFA concentrations at 24 to 36 hours of age is beneficial for twin- and triplet-born lamb thermoregulation during periods of cold stress.}, issn = {1176-5283}, author = {Kerslake JI and Kenyon PR and Morris ST and Stafford KJ and Morel PCH} } @conference {75919, title = {Predicting the benefits of two stage genomic selection in young breeding rams}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {266-269}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {A two stage selection index model was developed to assess the cost effectiveness of using genomic technologies to assist in selection decisions for retention of ram lambs for breeding within a ram breeder flock. The principle of two stage selection is that many of the benefits of an expensive, but more accurate, measure of genetic merit can be captured while drastically reducing measurement costs. This paper describes the two stage model used, and some of the potential benefits of testing the top 6{\textendash}50\% of selection candidates ranked according to estimated breeding values, prior to ranking on a combined score using genomic breeding values. The model assumes a hypothetical panel of markers and trait predictive accuracies to explore the benefits of selection using both types of breeding values. The value of genetic progress is assessed using selection index theory to predict trait changes according to a selection index recently revised for implementation as the recommended index for dual purpose sheep in New Zealand. Results suggest that maximum benefits were obtained when the top 10-20\% of selection candidates were tested, with the level of benefits dependent on both the prediction accuracy and price of the test.}, issn = {1176-5283}, author = {Sise JA and Linscott EM and Amer PR} } @conference {75860, title = {Presidential Address 2010 - What will it take to feed the world and what is the role of New Zealand animal production in this?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {1-2}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {A recent United Nation{\textquoteright}s report stated that the world{\textquoteright}s growing population will require twice as much food in 40 years time. What opportunities and challenges does this present for agricultural product producing countries? How will researchers meet the challenge of feeding a world population that is estimated to grow to 9 billion people by 2050? This is not an area that... Continued}, issn = {1176-5283}, author = {Back PJ} } @conference {75881, title = {Production variables influencing the auction sales price of New Zealand Thoroughbred yearlings}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {92-95}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {Data were obtained from the New Zealand Thoroughbred studbook and the online sales results for the 2004 National Yearling Sales Series. Across the three sales categories, 477, 523, and 354 yearlings were offered at the Premier, Select and Festival sales, respectively. There were significant differences in the representation of yearlings across the three sales categories based on: sire service fee, vendor category, purchaser country of origin, and dam age. There were fewer fillies catalogued in the Festival sale compared to Select or Premier sales (P <0.05). Within the general linear model, auction price (log10) was significantly influenced by sales category: Premier ($71,285, 95\% Confidence interval (CI), $61,801-$82,224), Select ($24,831, 95\% CI, $22,233-$27,733) and Festival ($9,462, 95\% CI, $8,072-$11,091, P <0.001). Sales price (log10) was also significantly influences by sire service fee, vendor category, purchaser country of origin, and mare age. Colts sold for more than fillies ($29,040, 95\% CI, $26,668-$31,695 vs. $22,542, 95\% CI, $20,370-$24,945, P <0.001) across all sales categories with an interaction of sales category and gender (P = 0.003). These results indicate that in order to optimize gross returns, vendors require colts that are marketed through the Premier sale, from older established broodmares, with a pedigree that appeals to Australian buyers.}, issn = {1176-5283}, author = {Waldron K and Rogers CW and Gee EK and Bolwell CF} } @conference {75920, title = {Raising lambs with intact tails to meet retailer welfare requirements: on farm feasibility and farmer perspectives}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {270-274}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {The aim was to study the practical feasibility of raising lambs with intact tails to satisfy welfare concerns over tail-docking. On four farms, two groups of ewes were bred with either a farm ram (Normal) or a Dorper ram (Dorper). Lamb body weight and dag scores were monitored at weaning and before transport to slaughter. Tail length was measured at weaning. Dorper-sired lambs were not tail-docked. Farmers recorded all management procedures and participated in a post-trial questionnaire. On average, the number of handling and health treatments, farm labour and measurements at weaning and transport were similar for the Normal and Dorper-sired lambs. Dag scores averaged 1.2 and 1.3 at weaning, and 0.6 and 0.8 at transport for Normal and Dorper-sired lambs, respectively. Three farms returned a higher value/head for their Dorper-sired lambs. Three farmers stated they would not raise lambs with intact tails in the future unless they received a higher premium. One farmer reported that he would continue to raise undocked Dorper-sired lambs. These results suggest that while it is possible to meet retailer demands for higher welfare standards by raising lambs with intact tails, industry uptake may be dependent on higher premiums that satisfy the perceived extra costs of the farmers.}, issn = {1176-5283}, author = {Rogers AR and Dowling SK and Webster JR} } @conference {75896, title = {The role of breeding in reducing sheep GHG intensity}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {162-167}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {Historic and potential future greenhouse gas (GHG) emission reductions resulting from genetic selection decisions in sheep have been quantified. Historic genetic trends in number of lambs born in maternal breeds and growth in terminal sire breeds were estimated to have reduced GHG emissions per kilogram of lamb carcass weight by 0.45\% and 0.09\% per year of genetic change, respectively. The implications of future selection using different indexes were also examined. Selection based solely on farm profits could lead to emission reductions per unit of product by 0.185 kg CO2-e/kg carcass weight, or a 0.59\% reduction in lamb carcass weight emissions per annum. Selection of sheep ignoring profit and solely targeting reduced GHG emissions per kilogram of lamb carcass weight could lead to emission reductions of 0.242 kg CO2-e/kg lamb carcass weight, equivalent to a 0.77\% reduction in total emissions per annum. However, doing this would come at a cost of 26.6 cents per breeding ewe reduction of 23.7\% per annum in annual genetic progress. An alternative index that provides a balance between reducing GHG emissions and improving farm profits was estimated to produce an annual 0.193 kg CO2-e/kg carcass weight or a reduction of 0.62\% reduction in emissions per annum in GHG emissions with minimal sacrifice in genetic improvement of farm profitability. }, issn = {1176-5283}, author = {Ludemann CI and Byrne TJ and Sise JA and Amer PR} } @conference {75894, title = {The role of legislation in improving farm sustainability and how the New Zealand Government intends to incentivise the agricultural industry}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {152-156}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {The New Zealand Government has put in place a number of mechanisms aimed at improving farm sustainability and incentivising action. In relation to climate change, the key mechanism is the New Zealand Emissions Trading Scheme (ETS), which has been designed to put the New Zealand economy on a path to lower greenhouse gas (GHG) emissions and to respond to the country{\textquoteright}s international obligations. Although all developed countries that have ratified the Kyoto Protocol are responsible for their agricultural emissions, New Zealand is the only country in the world to include agriculture in an emissions trading scheme. With the inclusion of agriculture there are three key ways to incentivise a reduction in GHG emissions on-farm. These are through the point of obligation, the emission factor methodologies, and the allocation of "New Zealand Units" to the sector. Introducing agricultural GHG emissions into a New Zealand emissions trading scheme brings with it challenges and opportunities in a country that is heavily reliant on primary production for the health of the economy.}, issn = {1176-5283}, author = {van Reenen EH and Pickering AH} } @conference {75909, title = {Is rumen retention time implicated in sheep differences in methane emission?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {219-222}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {Breeding ruminants for low methane (CH4) emissions is an attractive mitigation approach for this greenhouse gas. During the last three years research has progressed at AgResearch to accurately identify individual sheep with contrasting low (Low) and high (High) methane yields. A study was conducted using these animal resources in order to explore the animal factors responsible for the observed differences between rankings. For this, the sheep were fed first on fresh pasture forage (pasture) and then on pellets containing lucerne hay and wheat grain (pellet). Methane emissions were measured in respiration chambers over two consecutive days. Feed dry matter digestibility (DMD) was estimated from a total faecal collection, whereas ruminal retention times of feed particles (PRRT) and solutes (SRRT) were estimated by single dosing of external markers. Methane yields from the High sheep were higher (P >0.05) than from their Low counterparts both the pasture and pellet diets. High emission ranking sheep had higher (P <0.05) DMD and SRRT than their Low counterparts, whereas PRRT was only numerically higher for the High sheep than for the Low sheep. Results of this study align with previous findings that retention time of digesta is implicated in animal differences in CH4 emission.}, issn = {1176-5283}, author = {Pinares-Pati{\~n}o CS and Ebrahimi SH and McEwan JC and Dodds KG and Clark H and Luo D} } @conference {75912, title = {Ruminal fermentation characteristics from sheep offered a fresh grazing allocation of a ryegrass-based pasture either in the morning or in the afternoon}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {234-239}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {Eight rumen-fistulated wethers were used to examine the effects of PM (16:00 h) versus AM (08:00 h) allocation of spring herbage from pasture on aspects of ruminal metabolism that lead to increased utilisation of nutrients. The experimental period consisted of two phases; adaptation to diets and intensive sampling. During the adaptation phase, total volatile fatty acids (VFA) and ammonia concentrations were greater for the PM group, whereas the ratio of non-glucogenic to glucogenic VFA did not differ. These results suggest greater fermentation from forage that had similar concentrations of crude protein, neutral detergent fibre, and water soluble carbohydrates, but greater organic matter digestibility (84.1 vs. 82.3\%). During the intensive sampling phase, the mean total VFA and ammonia concentrations did not differ among groups, but the 24-hour pattern varied considerably for all variables measured. Unseasonal weather conditions during the trial were associated with smaller differences in water soluble carbohydrate accumulation than expected. Based on our results, at least four hours of sunshine were needed to obtain diurnal differences greater than 20 g per kg herbage DM. The implication of these findings on the implementation of nutritional management strategies warrants further investigation.}, issn = {1176-5283}, author = {Vibart RE and Burke JL and Pacheco D} } @conference {75887, title = {Selection decisions in Thoroughbred broodmares}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {122-125}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {Using retrospective racing and breeding records the hypothesis was tested that in the last two generations there has been a significant increase in the proportion of race tested fillies entering breeding. During the 1998/99 breeding season there were 146 sires at stud, 92 had a Low cost service fee (<$5,000), 28 had a Medium cost service fee ($5,001-$10,000), 9 had an Expensive cost service fee (>$10,000) and 17 were Shuttle stallions. Of the 6,768 mares covered 46\% were covered by Low cost, 22\% by Medium cost, 12\% by Expensive cost and 19\% by Shuttle stallions. Three stallions from each of these four service fee categories were randomly selected and the opportunity for the female progeny sired by these stallions to enter yearling sales, race and enter the broodmare herd were examined. Significantly more 1999 born female progeny by Expensive (37\%) and Shuttle stallions (34\%) were presented for sale than those by Medium (1\%) and Low cost sires (0\%), and were more likely to race (85\% and 82\%) than those by Medium or Low cost sires (64\% and 50\%). Female progeny born in 1999 by Expensive sires were more likely to enter breeding (80\%) than those by Shuttle (49\%), Medium (43\%) or Low cost sires (25\%). The proportion of broodmares with race records decreased with each retrospective generation.}, issn = {1176-5283}, author = {Rogers CW and Gee EK} } @conference {75926, title = {Sub-clinical uterine infection is associated with altered amino acid concentrations of follicular fluid in early lactation dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {296-300}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {The effect of sub-clinical endometritis (scEndo) in early lactation on follicular amino acid (AA) concentrations was determined. On D21 and D42 postpartum cows were classified as having scEndo or Clean based on uterine cytology; >18\% polymorphonuclear (PMN) cells amongst uterine nucleated cells. On D21 and D42, 35\% and 7\% of cows respectively were classified as having scEndo, with a large proportion of scEndo cows having self-resolved the infection by D42. Follicular histidine (P = 0.04), as well as alanine, aspartate and serine concentrations (P <0.1) were higher in scEndo compared with Clean cows. The effect of change in uterine status from D21 to D42 resulted in increased (P <0.1) follicular glutamate, ornithine and valine concentrations in cows that resolved infection. Correlation coefficients were determined to test the relationship between plasma and follicular AA concentrations. A greater number of AA in Resolved cows showed no relationship between plasma and follicular concentrations compared to Clean cows. Thus, scEndo is associated with an increase in follicular histidine and an increase in the concentration of several AA when a uterine infection is resolved. This study demonstrates that scEndo may be responsible for long-term alterations in follicular AA concentrations that could potentially result in altered oocyte viability.}, issn = {1176-5283}, author = {Back PJ and Lopdell T and Berg MC and Green MP} } @conference {75861, title = {Temporary alterations to milking frequency, immediately post-calving, modified the expression of genes regulating milk synthesis and apoptosis in the bovine mammary gland}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {3-8}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {Temporary changes to milking frequency during early lactation can elicit lactation-long changes in milk production. This study tested whether altered milking frequency, immediately post-calving, would affect mammary gene expression during and/or following treatment. Multiparous, grazing dairy cows (n = 150) were allocated to one of five treatments post-calving: milking thrice-daily (3X) for three or six weeks, and twice-daily (2X) thereafter; milking once-daily (1X) for three or six weeks, and 2X thereafter; or milking 2X for the entire lactation. Mammary tissue was biopsied from 12 cows per treatment at three, six and nine weeks postcalving and expression of milk synthesis and apoptosis genes measured using quantitative PCR. The milk fat, lactose and protein genes were down-regulated (P <0.05) in cows milked 1X compared with cows milked 2X. At nine weeks post-calving, cows milked 1X for three weeks had reduced mRNA levels of milk synthesis genes compared with cows milked 1X for six weeks (P <0.05). The expression of apoptosis genes was up-regulated (P <0.05) in cows milked 1X relative to 2X, during and post-treatment. There were no gene expression changes during 3X milking compared with cows milked 2X. Changes in gene expression observed in cows temporarily milked 1X reflect physiological changes consistent with longer-term reductions in milksolids yield.}, issn = {1176-5283}, author = {Grala TM and Phyn CVC and Kay JK and Rius AG and Littlejohn MD and Snell RG and Roche JR} } @conference {75917, title = {Is there an association between dam live weight and litter structure in a flock of grazing Perendale sheep?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {257-262}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {Observational data from a grazing Perendale flock collected between 1985 and 2002 were analysed to investigate whether there was any association between variation in pasture availability over the summer, as reflected in live weight at joining and/or liveweight change between weaning and the subsequent joining, in association with litters of different sizes and sex structure, and the sex ratio of lambs born during the following spring, under pastoral farming conditions. The flock was managed at Whatawhata Research Centre until 1997 and thereafter at Winchmore Research Station. Data for a total of 3,516 lambs were analysed. Between year variation and variation associated with all the assessed factors, was consistent with chance variation. The proportion of males born was not significantly different from 0.50. Ewe age was significant at Winchmore when adjusted for lambing year, and litter size in both the previous and current lambings and liveweight change of the dam between weaning and joining, with more males born to mature ewes. Three percent more male than female lambs died between birth and weaning at both locations. It is unlikely sheep farmers can consistently influence the sex ratio of their lamb crop through changes in their flock management procedures.}, issn = {1176-5283}, author = {Sumner RMW and Henderson HV and Sheppard AM} } @conference {75878, title = {Is there any advantage of early weaning of twin lambs born to yearlings?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {79-82}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {The objective of the current study was to investigate the effect of weaning twin lambs born to yearlings at 9, 11 or 13 weeks of age on the live weight of the yearling and her lambs. The yearlings and the lambs were allocated to one of three weaning treatment groups (9-week versus 11-week versus 13-week) on Day 1. Each treatment group was balanced for yearling and lamb live weight. At Week 13, all lambs were removed from the remainder of the experiment but the yearlings were monitored for a further six weeks. The yearlings and lambs were offered ad-libitum levels of herbage throughout the experimental period and the pre- and post-grazing mass was monitored weekly. The yearlings and lambs were weighed on Days 1, 7, 14, 21 and 28 while yearlings were weighed again on Days 35, 42 and 70. Pre- and post-grazing mass was monitored weekly. Yearling live weight did not differ (P >0.05) between treatment groups on Days 1, 35 or 70. Lamb live weight did not differ (P >0.05) on Days 1, 14 or 28. These results indicate that there is no advantage of early weaning of twin lambs born to yearlings on the live weight of the yearling or her lambs.}, issn = {1176-5283}, author = {Mulvaney FJ and Morris ST and Kenyon PR and Morel PCH and West DM} } @conference {75886, title = {An update on genetic parameters for facial eczema susceptibility in New Zealand dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {117-121}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {Resistance/tolerance to facial eczema (FE) is a heritable trait in New Zealand dairy cattle, as measured by genetic variation in liver enzyme levels. AgResearch has been collecting data from herds clinically affected by FE, by blood-sampling all cows in these herds, as a low cost method of phenotyping large numbers of animals. Over the past seven autumns, 66 herds and 14,799 cows were sampled. Breeding values for FE resistance were calculated for 238 sires. One complicating factor was the level of FE-protection provided by zinc sulphate administered through the farm water supply. Variable levels of serum zinc in cows were found, due to factors including water intakes and weather conditions. In zinc-treated herds there were three classes of cows: those still affected by FE, and others seemingly FE-tolerant either through genetics or having enough circulating zinc to provide protection. The zinc status of each herd was recorded at the time of blood sampling after a clinical outbreak. Data were analysed within zinc-treated and not zinc-treated herds to provide genetic parameters for each. Heritabilities in herds according to zinc status were very similar, regardless of zinc status.}, issn = {1176-5283}, author = {Cullen NG and Morris CA and Hickey SM and Henderson HV} } @conference {75904, title = {The welfare implications of dystocia in sheep and cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {194-197}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {Painful husbandry procedures are routinely performed on farms in New Zealand for various reasons. Tail docking is routinely carried out on sheep to prevent flystrike and on pigs to prevent tail biting. In some countries this procedure is still performed on dairy cows to improve udder hygiene and worker comfort. Castration is commonly performed on lambs and calves to reduce aggressive and sexual behaviours, prevent unwanted breeding, and modify carcass characteristics. Dehorning is performed on cattle to reduce the risk of injury to stock people and other animals and antler removal in deer is carried out for commercial reasons. All of these procedures cause behavioural and physiological changes indicative of pain, but are commonly performed without pain relief on farms. This review will cover the rationale and the behavioural and physiological responses caused by these common husbandry procedures. Possible methods of pain relief or alternative strategies to these procedures will then be discussed as well as the implications for New Zealand and where future research needs to be focussed.}, issn = {1176-5283}, author = {Stafford KJ} } @conference {75901, title = {The welfare of extensively farmed livestock}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {181-185}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {Extensive farming involves husbandry of animals over a large area, animal performance, health and welfare dependent on ecology and farm management. Specific features providing both challenges and opportunities for good animal welfare include climatic, environmental and nutritional variation and extremes; infrequent human contact; greater freedom for animals to make choices affecting their well-being; a greater degree of natural selection; and fitter animals better able to cope with their environments. Stockmanship, in addition to drawing on personal experience and traits, requires an understanding of the constraints and opportunities afforded by the climate, the terrain and the biota. Intensification practices acting to increase productivity and efficiency need to be able to retain and enhance animal resilience to environmental changes. Animal welfare regulatory, monitoring and assurance expectations may need to acknowledge these distinctive features.}, issn = {1176-5283}, author = {Fisher MW} } @conference {75877, title = {Why is clover better than ryegrass?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {71-78}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {This review quantitatively compares the nutritive value of ryegrass and clover. It confirms that the animal performance on clover is on average 40\% higher than on ryegrass. It establishes that although the digestibility of clover is less affected by stage of vegetative growth than ryegrass, the digestibility and metabolisable content of the two species is little different when compared at a young vegetative stage. Although the crude protein content of clover is often higher than that of grass the ratio of metabolisable protein to metabolisable energy supply is similar from the two forages. Despite a similar metabolisable energy content, the utilisation of metabolosable energy for growth is higher for clover than ryegrass. This may be due to a greater proportion of energy digestion in the small intestine. Most of the elements of ingestive behaviour, bite size, biting rate and intake rate are greater for clover than ryegrass and consequently the total gazing time and thus cost of harvesting clover are lower. The review concludes by estimating the relative contribution of increased efficiency of utilisation, reduced costs of ingestion and increased intake to the higher animal performance from clover.}, issn = {1176-5283}, author = {Nicol AM and Edwards GR} } @conference {69516, title = {Application of genomic information in a dairy cattle breeding scheme}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {253-256}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Marker assisted selection has been applied in dairy cattle breeding schemes over the last decade with minor to moderate improvements in genetic gain. In most cases, the cost effectiveness of marker assisted selection has been neutral, at best. The completion of the sequencing of the bovine genome in 2006 has generated a large number of single nucleotide polymorphisms that has allowed the application of genomic selection. In addition, the cost of genotyping single nucleotide polymorphisms is considerably lower than microsatellite genotyping. Livestock Improvement Corporation has undertaken extensive genotyping of the sires that have been progeny tested in the last 20 to 30 years. Analysis of these data by Livestock Improvement Corporation researchers has identified combinations of markers that were used to obtain genetic evaluation of bulls from their DNA. By utilising this genomic information, semen from two-year-old sires has been sold to New Zealand dairy farmers. Over the past two years, the genomically selected bulls have accounted for approximately 15 to 20\% of the inseminations. It is expected that selection based on genomic information, termed genomic selection, will increase the rate of genetic gain in New Zealand by 30 to 50\%.}, issn = {1176-5283}, author = {Spelman RJ and Arias J and Keehan M and Obolonkin V and Winkelman A and Johnson D and Harris BL} } @conference {69527, title = {Application of resource allocation optimisation to provide profitable options for dairy production systems}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {291-295}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {A linear program (LP) model analysed resource use on a 100 ha dairy farm. A single optimum-profit combination was established for resources which were either optimised or constrained. It was found that, with a fixed herd of 320 milking cows, when production increased from 305 kg milksolids per cow (kg MS/cow) to 415 kg MS/cow, cash profit increased by 65\%. This required additional supplements. If, however, feed demand and supply were optimised at 415 kg MS/cow, the LP reduced milking cow number rather than buy in feed to meet the increased feed demand from higher production per cow. At all production levels chosen between 305 and 415 kgMS/cow, it was most economic to dry off and cull cows early in dry summers to optimise feed demand vs. feed grown; use nitrogen (N) fertiliser to avoid a feed deficit only when response rates of better than 10 kgDM to 1 kg N could be expected; not use N for growing supplements to harvest. Pasture cover, within defined constraint levels, provided a buffer for feed demand and supply fluctuations. The study highlights the importance of assessing production, income and cost in an integrated framework to identify the point at which individual resources become limiting.}, issn = {1176-5283}, author = {Anderson WJ and Ridler BJ} } @conference {69469, title = {Asssociation among hormones and metabolites during the transition period and early lactation milk production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {51-56}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {The transition period is loosely defined as the period from three weeks pre-calving to three weeks post calving, and is regarded as a very important determinant of a cow{\textquoteright}s lactation performance. Data were collated from three experiments in which blood was sampled repeatedly pre- and post-calving and milk production was recorded post-calving. Data were pooled within treatment and associations between blood hormones and metabolites, and milk production determined using regression analysis. Milk and milk solids (MS) yield were positively associated (P <0.05) with pre-calving plasma leptin and glucose concentrations and milk yield was negatively associated (P <0.05) with pre-calving non-esterified fatty acid (NEFA) and β-hydroxy butyrate concentrations. Milk yield was negatively associated (P <0.05) with plasma growth hormone, aspartate aminotransferase, and glutamate dehydrogenase concentrations in the first days of lactation, and with insulin like growth factor and glucose concentrations during the first five weeks post-calving. In comparison, plasma NEFA and albumin (ALB) concentrations post-calving and the ratio of NEFA to ALB were all positively associated (P <0.05) with milk and MS yield during the first five weeks of lactation. Data are consistent with a positive effect of calving body condition on milk production and an increased milk production with increasing condition score loss post-calving.}, issn = {1176-5283}, author = {Edwards P and Mandok K and Lee JM and Burke CR and Kolver ES and Roche JR} } @conference {69460, title = {Automatic reading of Kamars for heat detection in dairy herds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {8-12}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Most existing heat detection systems for dairy cattle are labour-intensive requiring manual inspection of every animal to maximise submission rates. Our solution is to automate heat detection using Kamar HeatMount Detectors and a camera-based recognition system. The goal of our system is to obtain 99\% sensitivity and specificity, ensuring that cows that are on heat are rarely missed and over-drafts are kept to a minimum. Trials of various camera prototypes have been undertaken over the past three years, most recently during the artificial breeding period in the Spring of 2009. Over 70,000 images from four farms were taken during the latest trials; these photographs were used to assess the system. When considering photo observations, the fully automated system had an error rate less than 1\% across all sites in the latest trial, and reaches our goal of 99\% sensitivity and specificity. }, issn = {1176-5283}, author = {Hempstalk K and Harris BL and Lopdell TJ} } @conference {69532, title = {Blood metabolic profiles in Uruguayan Holstein and Uruguan Holstein x New Zealand Holstein-Friesian dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {311-315}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Blood metabolic profiles were determined from 40 days prepartum to 60 days postpartum in Uruguayan Holstein (UH) (n = 13) and UH x New Zealand Holstein-Friesian first cross (UH-NZHF) (n = 13) cows with seven in each group experiencing their second lactation (L2) and six experiencing their third lactation (L3). Non-esterified fatty acids increased around calving and tended to be greater in UH-L3 cows as well as betahydroxybutyrate concentrations for 20 days after calving, consistent with the greater body condition score losses in this group. The UH cows had greater prepartum total protein concentrations than UH-NZHF cows. Concentrations decreased around calving and increased immediately thereafter. In UH-NZHF-L2 cows, total protein levels were consistently low throughout lactation. UH-NZHF L3 cows had greater albumin concentrations than UH L3 cows. Insulin concentrations were not affected by strain or lactation number and were diminished around calving. A similar pattern was found for IGF-1, although an interaction between strain and days-in-milk was found. Compared to UH cows, UH-NZHF cows had greater levels of IGF-1 at 35 days prepartum but lower levels of IGF-1 at calving. These data suggest that UH cows, especially L3 cows, had a more pronounced negative energy balance than UH-NZHF cows that may reflect a different pattern of nutrient partitioning possibly related to different pregnancy rates.}, issn = {1176-5283}, author = {Periera I and Laborde D and Lopez-Villalobos N and Ruprechter G and Carriquiry M and Meikle A} } @conference {69522, title = {Can ultrasound eye muscle area scanning be used in the New Zealand deer industry?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {275-277}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {The New Zealand Deer Industry Productivity Strategy 2009-2014 (Deer Industry New Zealand, 2009) aims to increase deercarcass weight by 10\% and introduce a carcass yield module to their performance recording database DEERSelect. In other livestock species real-time ultrasonography offers a non-invasive, non-destructive, standardised muscle measurement on live breeding stock (Faulkner et al.,1990). Ultrasound scanning allows eye muscle (M. longissimus dorsi)dimensions and cross-sectional area to be recorded as traits for genetic evaluation in the Sheep (SIL) and Beef (BREEDPLAN) performance recording databases.}, issn = {1176-5283}, author = {Ward JF and Archer JA and Farmer RJ and Sweetman MF and Nicoll GB and JV Yuan} } @conference {69487, title = {Carcass linear measurements as predictors of meat yield in lambs determined by VIAscan}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {130-132}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Lambs yielding proportionally more lean meat are desirable to processing companies as they have a greater quantity of saleable product which also meets market demand withoutthe need for further processing. The quest for higher yielding lean lambs has seen a change in the lamb carcass grading system from classification on carcass weight and the GR measurement (total tissue depth above the 12th rib, 110 mm from the midline) (Kirton, 1989) to using imaging systems such as VIAscan{\textregistered}. VIAscan{\textregistered} is a two dimensional imaging system that estimates lean content of the carcass (Hopkins et al., 2004).}, issn = {1176-5283}, author = {Bain WE and McEwan JC and McLean NJ and PL Johnson} } @conference {69513, title = {Cathelicidin levels in milk from cows infected with a range of mastitis causing pathogens}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {243-245}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Mastitis is an inflammatory condition of the udder that is highly prevalent in cows on New Zealand dairy farms. It results in reduced production, increased treatment costs and lower profitability (Petrovski et al.,2006). An elevated somatic cell count (SCC) in the milk, mainly due to recruitment of immune cells to the site of infection, is the most widely accepted standard for diagnosis of subclinical infection whereas bacteriological culturing is typically used for identification of the causative pathogen from clinical cases (Moyes et al.,2009; Schukken et al.,2003). At present, both tests require laboratory analysis and are not routinely performed on individual cows throughout lactation.}, issn = {1176-5283}, author = {Pryor SM and Smolenski GA and Wieleczko RJ and Broadhurst and Stelwagen K and Wheeler TT and Haigh BJ} } @conference {69461, title = {Circulating levels of C-type natriuretic petide (CNP) are strongly linked to pregnancy but not to liveweight change in ruminants}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {13-18}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Marked increases in plasma C-type natriuretic peptide (CNP) during ovine pregnancy, and decline during periods of imposed caloric restriction, raise the possibility that CNP concentrations in ruminants are associated with changes in live weight (LWT) and metabolic demands. Accordingly we measured plasma concentrations of CNP and a related amino-terminal fragment of proCNP (NTproCNP) at weekly intervals in pregnant (n = 8) and non-pregnant red deer hinds (n = 4) and non-pregnant ewes (n = 8) run concurrently. Plasma CNP forms increased markedly during cervine pregnancy to achieve peak concentrations (NTproCNP 132 {\textpm} 9.5 pmol/L, CNP 2.14 {\textpm} 0.2 pmol/L) at 38 and 10 days pre-partum respectively, falling in the final week of gestation to reach pre-pregnancy levels immediately post-partum (P >0.05). There was no association between the concentration of CNP forms and change in LWT in either group of non-pregnant ruminants. We conclude that maternal concentrations of CNP forms are markedly raised in pregnant deer exhibiting similar changes to those found previously in pregnant ewes, and that the observed changes in plasma levels are likely to be independent of change in LWT. Maternal plasma concentration of CNP forms may be a useful marker of fetal well-being and maturation in ruminant livestock.}, issn = {1176-5283}, author = {McNeill BA and Prickett TCR and Wellby M and Ridgway MJ and Espiner EA and Barrell GK} } @conference {69511, title = {Comparison of breeding values between sheep ranked for resilience and resistance}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {235-239}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {The sheep industry has put considerable resources into studying selection for resistance by measuring faecal egg count (FEC). Resistance can also have reduced pasture larval challenge as an important spin off. Fewer resources have been put into selecting for increased resilience, animals which are able to grow under challenge, possibly because methods of selecting resilient animals are more labour intensive and difficult to standardise. Te Whangai, which has a flock of 9,000 ewes, 2,500 of which are recorded ewes for breeding industry rams, has been working with AgResearch monitoring resilience and resistance in their flock since 2001. An analysis using data from ram lambs born in 2007 and 2008 found the top ranked animals on resilience had higher than average breeding values for growth and wool weights, whereas the top ranked animals for resistance with a low FEC, had lower than average breeding values for growth and wool weights. In 2007, the average breeding value for eight month live weight for the top 60 resilient lambs was 6.55 kg greater than that for the top 60 resistant rams. These findings suggest caution is advised in selecting animals on FEC. Resilience is likely to be a better alternative.}, issn = {1176-5283}, author = {de Lautour MB and de Lautour HB} } @conference {69506, title = {Composition and in sacco degradation characteristics of winter growth of Lolium perenne, Lolium multiflorum and Lolium perenne x multiflorum ryegrasses}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {206-212}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Nine ryegrass cultivars (3 perennial, 3 hybrid, 3 Italian types) were sampled during the winter of 2007 to measure chemical composition, degradation parameters and leaf morphology and to define differences that may be applicable to winter growth in dairy pastures. The grasses were harvested after seven and nine weeks of regrowth on June 18 and August 2. There were no differences between ryegrass types in the concentration (g/kg dry matter (DM)) of crude protein (227) but neutral detergent fibre was higher in perennial (468) than hybrid (435) or Italian (414) ryegrass types. Leaves were largest and widest for the Italian type, and shortest and narrowest for the perennials (P <0.001). Italian ryegrasses had the highest concentration of soluble DM. There were differences in the degradation rate (h-1) of insoluble DM; Italian (0.20), hybrid (0.18) and perennial (0.13) ryegrasses (P = 0.06). Ryegrass sampled after 9 weeks of regrowth, had a lower crude protein concentration than the earlier sampling (208 vs. 246) and a lower neutral detergent fibre concentration (392 vs. 486) but leaf characteristics, proportion of DM in the soluble fraction, and DM degradation rates were similar (P >0.05). The identification of differences in composition and degradation will assist with planning grazing management over winter.}, issn = {1176-5283}, author = {Sun XZ and Waghorn GC and Clark H} } @conference {69526, title = {Condensed tannins for priming innate immunity}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {288-290}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {The immune system of sheep, cattle and other ruminants contains unusually large numbers of gamma-delta () T lymphocytes. In lambs and calves, these cells may comprise more than 50\% of the T cells circulating in blood while in rodents and primates, they typically account for less than 5\% of blood-borne T cells. The T cells localise within mucosal surfaces of all species, particularly in the gastrointestinal tract. Compared to their rodent and human counterparts, ruminant T cells have a greatly expanded repertoire of antigen receptors (Hein \& Dudler, 1993, 1997). They also express unique accessory molecules in their cell membrane which may reflect a differential capacity of the ruminant T cells to contribute to immune defence (Hein \& Mackay, 1991).}, issn = {1176-5283}, author = {Schreurs NM and Pernthaner A and Hein WR and Barry TN} } @conference {69505, title = {Correlated responses following genetic selection to change age at puberty in Angus cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {202-205}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Direct and correlated responses in a 23-year selection experiment to change puberty in heifers are reviewed. Selection was for age at first oestrus (AFO). It was applied in both sexes, using the genetic correlation (-0.25 {\textpm} 0.09) between scrotal circumference in juvenile males and AFO in female relatives. The main breeding lines were those selected for early AFO (AGE-), late AFO (AGE+), or unselected (Control). A 69-day difference (19\% of the herd mean) was achieved between the two AGE lines, with a 3.0 cm (9.9\%) difference in scrotal circumference. Relative to the AGE+ line, the AGE- line means were +10.8 {\textpm} 3.1 kg (3.9\%) in yearling weight, -6.0 {\textpm} 3.0 kg (1.3\%) in cow mature weight, -47 {\textpm} 6 kg (16\%) in heifer weight at first oestrus, and +3.7 {\textpm} 1.5 percentage points for mixed-aged cow pregnancy rate. There were significantly fewer sub-fertile yearling bulls in the AGE- line (P <0.001), and maternal effects on autumn and winter weights on calves of this line were positive. For carcass composition, only depot fat differed significantly between lines (AGE- mean < AGE+ mean). No major unfavourable traits were observed in the AGE- line in this study.}, issn = {1176-5283}, author = {Morris CA and Amyes NC} } @conference {69510, title = {Correlated responses following genetic selection to change faecal egg count in Romney}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {229-234}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Genetic studies of nematode parasite-related traits were carried out in New Zealand Romney sheep between 1979 and 2006. Breeding lines were selected for high or low faecal worm egg count (FEC), and managed alongside a control unselected line. FEC data were collected from lambs post-weaning, whilst exposed to continuous, natural, mixed-species, nematode parasite challenge under grazing conditions. Overall there were 33,314 records of lamb FEC, taken at {\textquoteleft}FEC1{\textquoteright} and {\textquoteleft}FEC2{\textquoteright} (first and second post-weaning sampling times, separated by a drench treatment). Genetic parameter estimates are reviewed, including correlations of FEC with lamb, anti-parasite antibody and ewe performance traits. The heritability of FEC in lambs was 0.26 {\textpm} 0.01 overall, with a repeatability of 0.40 {\textpm} 0.01. The genetic correlation between FEC1 and FEC2 was 0.85 {\textpm} 0.02. Trends were for low FEC to be associated genetically with slight reductions in post-weaning growth, and in ewe and lamb fleece weights, minimal change in autumn and yearling live weights, and increased weaning weight, dag score and anti-parasite antibody levels. In practice, ram breeders would normally use index selection procedures, to achieve higher production at the same time as a lower FEC, although a slower rate of change in FEC would be expected.}, issn = {1176-5283}, author = {Morris CA and Wheeler M and Shaw RJ} } @conference {69502, title = {Crossing Angus cattle with Limousin as a method of increasing meat yield}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {189-193}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {The myostatin mutation in Limousin cattle affects both dressing percent and meat yield, without a negative impact on calving difficulty. A trial was designed to introgress this mutation into Angus cattle, using double-copy Limousin bulls to produce F1 Limousin x Angus. Crossing the F1 individuals would produce F2 individuals with a quarter carrying two copies of the mutation. A pure-bred Angus herd was maintained as a Control, for breed and genotype comparisons. A total of 269 F1, 34 F2 and 129 Angus calves were born in the first four years of this trial, before a lack of funding led to early closure. A total of 112 surplus bulls were slaughtered, and measurements taken over three years, including a {\textquotedblleft}butchers{\textquoteright} dissection{\textquotedblright} into saleable meat, fat and bone of one hind-quarter per animal. Limousin crosses were 9\% heavier as yearlings, 7\% heavier at slaughter and had 2.3\% higher dressing percent (55.3\% vs. 53.0\%) than Angus. Hindquarters from Limousin crosses were 14\% heavier than from Angus, and their meat yields were greater by 1.8\% (77.0\% vs.75.2\%), due mainly to breed differences in bone weight. Overall, the Limousin-cross advantage was 6.5 kg (17\%) of saleable meat per hind-quarter, with most of the extra meat in high-value cuts.}, issn = {1176-5283}, author = {Cullen NG and Morris CA and Taukiri KR and Hill SW} } @conference {69517, title = {Daily water intake by individual cows on a pasture diet during mid lactation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {257-260}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Three small studies were undertaken in the Waikato involving daily measurements of water intake of individual mixed-age Holstein-Friesian and crossbred cows, mid lactation. In Trial 1 at Ruakura, cows were monitored whilst grazing and, in Trials 2 and 3 at DairyNZ, pasture was cut and fed to cows indoors. Mean daily water intakes by Trial were 41.3, 78.2 and 60.1 L/cow, respectively; standard deviations were 4.5, 8.3 and 7.2 L/cow, and between-cow repeatabilities averaged 0.56 {\textpm} 0.08. There were two days of rain in Trial 1; the greater of these rainfalls (26.4 mm) led to a 62\% reduction in water intake. There was no rainfall above 2 mm in Trials 2 or 3. Daily feed intakes (and feed dry-matter percentages) of cows were also available (Trials 2 and 3), and combined daily water intake (calculated from actual-water intakes plus water content of the feed consumed) averaged 104.5 and 110.6 L/cow, respectively. At an average water intake from the trough of 60 L/cow, the 25\% of cows drinking least are expected to drink ~8.4 L (14\%) less than average. This knowledge is useful when planning management practices such as supplementing water with zinc sulphate for facial eczema protection.}, issn = {1176-5283}, author = {Morris CA and Hickey SM and Thom ER and Waugh CD} } @conference {69523, title = {Deer Improvement{\textquoteright}s breeding scheme for venison production in red deer (Cervus elaphus)}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {278-282}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {This paper describes the progress of the Deer Improvement breeding scheme that has been in place since 2004. The aim of the programme is to improve venison production through genetic selection for growth rate of lean meat with improved fertility, temperament and mature hind weight. The breeding programme currently comprises 500 hinds bred from stags selected for high growth rate with the intention of increasing hind numbers to over 1,000. This projected increase will be facilitated by the use of embryo transfer to multiply the genes of the top ranked yearling animals, thus shortening the generation interval. As part of the programme, all progeny are DNA parentage tested, weighed frequently during their first 12 months of life and temperament scored. Pregnancy and weaning rates are recorded in the nucleus and progeny testing herds. As a result of selection during the past six years, the average yearling weight has increased by 1.5 kg/yr over all farms involved in the breeding programme. In 2009, male fawns from the nucleus herd reached an average of 100 kg at seven months of age. This is greater than the current industry average of 75 to 78 kg for the same age.}, issn = {1176-5283}, author = {Quinn-Walsh EG and Johnson DL and Chardon J and Spelman RJ} } @conference {69486, title = {Determining taste panel traits which contribute to the overall liking of New Zealand lamb as assessed by a British sensory panel}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {127-129}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {New Zealand is the world{\textquoteright}s largest exporter of sheep meat with the United Kingdom being the single largest market (Meat \& Wool New Zealand, 2009). Hence, the acceptance of sheep meat in international markets is an important economic issue (Prescott et al.2001). For retail purchasers of meat in the United Kingdom the visual appearance, the eating experience, and their interaction will influence how much the consumer is willing to pay for the product (Savellet al., 1989). To ensure repeat purchases of high quality New Zealand lamb by United Kingdom consumers, it is important that the consumer enjoys the overall eating experience of the product.}, issn = {1176-5283}, author = {McLean NJ and PL Johnson and Charteris A} } @conference {69530, title = {Differences in follicle dynamics and the importance of luteal support in young and old cohorts of genetically identical dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {303-305}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {There has been a documented decrease in fertility in the modern dairy cow selected for milk yield (Pryce et al.,2004). This emphasises the need for farmers in a seasonal grass-based system such as that in New Zealand to correctly manage herd genetics in conjunction with nutrition to optimise cow reproductive performance. The question remains however as to the relative influence and interdependence of these two factors in establishing a pregnancy, as an optimal size for the ovulatory follicle is directly related to successful conception and pregnancy (Perry et al., 2005).}, issn = {1176-5283}, author = {Green MP and Back PJ and Berg MC} } @conference {69484, title = {Do fetuses from primiparous one-year-old ewes differ from those of multiparous mature ewes?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {118-120}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {The number of ewe-lambs (8 to 9 months of age) mated in New Zealand has increased to approximately 33\% over the last 15 years (Anon, 2009). There are many potential advantages to ewelamb breeding including higher net profits, more lambs produced per ewe productive lifetime, better use of spring herbage, increased efficiency, early recognition of fertility potential and increased rates of genetic gain (Hight, 1982). However, little is known about the long term impacts of selecting progeny born to these young ewes as replacement animals. There is some evidence from human studies to suggest that there may be negative impacts for both the offspring and to the first parity young mother (Lucas et al., 1999).}, issn = {1176-5283}, author = {Loureiro MFP and Pain SJ and Kenyon PR and Blair HT} } @conference {69498, title = {Do lambs within twin- and triplet-born litter produce different amount of heat during a cold stress event?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {171-174}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Triplet-born lambs have been shown to have lighter birth weights (Morris \& Kenyon, 2004; Kerslake et al., 2005; Everett-Hincks \& Dodds, 2008), lower rectal temperatures (Dwyer \& Morgan, 2006; Stafford et al., 2007), lower plasma fructose (Stafford et al., 2007) and greater plasma lactate concentrations within five minutes of birth (Stafford et al., 2007; J.I. Kerslake, Unpublished data) than twin-born lambs. In addition to this, within a tripletborn litter, the lightest lambs have been shown to have lower rectal temperatures and greater plasma lactate concentrations within five minutes of birth (Stafford et al., 2007; J.I. Kerslake, Unpublished data) than the heaviest lambs. Light birth weights, low rectal temperatures and greater plasma lactate concentrations within five minutes of birth have been used as indices for placental insufficiency, acute intra-partum hypoxemia and inadequate thermogenesis after birth (Barlow et al., 1987; Mellor, 1988).}, issn = {1176-5283}, author = {Kerslake JL and Kenyon PR and Stafford KJ and Morris ST and Morel PCH} } @conference {69494, title = {Effect of age, live weight and dry matter intake on total tract nutrient digestibility in adult mares}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {152-156}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {The effects of age, live weight (LW) and dry matter intake (DMI) on the total tract digestibility of dry matter (DDM), organic matter (DOM), energy (DE), nitrogen (DN), neutral detergent fibre (DNDF), acid detergent fibre (DADF) and minerals (DCa, DK, DMg, DNa, DP and DS) were investigated in adult thoroughbred mares. Twenty mares, aged between 7 and 16 years (mean = 11.9; standard deviation {\textpm} 3.1) and weighing 508 to 650 kg (559.5 {\textpm} 36.7 kg) were offered 13 kg of feed per day consisting of 9 kg meadow hay, 3 kg barley and 1 kg lucerne chaff. Total faeces were collected over six days following a 20 day adaptation period. The average digestibility values were DDM: 0.59 {\textpm} 0.04; DOM: 0.63 {\textpm} 0.03; DN: 0.54 {\textpm} 0.08; DNDF: 0.44 {\textpm} 0.04, DADF: 0.38 {\textpm} 0.06, DE: 0.59 {\textpm} 0.04; DCa: 0.48 {\textpm} 0.08; DK: 0.68 {\textpm} 0.07; DMg: 0.27 {\textpm} 0.11; DNa: 0.63 {\textpm} 0.13 DP: 0.17 {\textpm} 0.11; and DS: 0.59 {\textpm} 0.05. Age was only related to DS. DMI (9.16 kg {\textpm} 1.1 kg) was negatively correlated (P <0.05) with DDM, DOM and DE while LW was positively correlated (P <0.05) with DDM, OM, DN, DNDF, DADF and DE. Mineral digestibility was not affected by LW or DMI. It is concluded that feed allowances should be adjusted for LW and/or DMI when a given amount of digestible nutrients are provided. }, issn = {1176-5283}, author = {Morel PCH} } @conference {69481, title = {Effect of birth weight on survival of lambs born to ewe lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {101-103}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Benefits of ewe lamb mating (at 8 to 9 months of age) include improved lifetime production, increased rates of genetic gain and higher net profits (Kenyon et al., 2008 and references therein). These benefits of ewe lamb mating are only achieved if the ewe lamb successfully rears its offspring to weaning. For mature ewes, a reduction of mortality before weaning by 1\% is equivalent to an extra $10 gross margin per hectare (Morel \& Kenyon 2006). To maximise farm profits it is necessary to understand the factors that influence pre-weaning mortality of lambs born to ewe lambs so that appropriate management strategies can be implemented.}, issn = {1176-5283}, author = {Schreurs NM and Kenyon PR and Morris ST and Morel PCH} } @conference {69473, title = {The effect of growth hormone on the intracellular amino acid profiles in mammary gland of lactating cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {67-70}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {The dairy industry is a cornerstone of the New Zealand economy, and increasing milk production, especially milk protein, is essential to boost farmer profits and meet global demand for milk products. Increasing the milk protein output per unit of intake also has positive environmental effects, due to more nitrogen being partitioned towards product, rather than excreta (Pacheco \& Waghorn, 2008).}, issn = {1176-5283}, author = {Pacheco D and Treloar BP and McCoard SA} } @conference {69465, title = {Effect of growth hormone on the liver transcriptome profile during established lactation in the dairy cow}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {33-38}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Milk production involves a coordinated metabolic response from multiple tissues. Administration of growth hormone (GH) to lactating cows provides an endocrine signal that redirects nutrients towards milk production. Hepatic responses to GH define the nutrient supply to peripheral organs both directly and indirectly, through processes such as gluconeogenesis and endocrine modulation. However, the mechanisms controlling these processes in the liver itself have not been completely elucidated. Our objective was to evaluate the effect of GH on gene expression in the liver of lactating dairy cows. Using a 22,690 expressed sequence tags (EST) bovine cDNA microarrays, we examined differences in liver mRNA transcript profiles between four cows treated with a slow-release formulation of GH and four control cows treated with saline solution. We identified 38 unique transcripts in liver that met the criteria of having expression changes greater than +/- 1.2 fold and false discovery rates <0.05. Of these genes affected by GH, 29 were down-regulated and nine were up-regulated. The pathways most affected by GH were carbohydrate and lipid metabolism, molecule transport and small molecule biochemistry. This preliminary study provides further insights into the molecular changes involved in the effects of GH on liver gene expression in the lactating dairy cow.}, issn = {1176-5283}, author = {Pacheco D and Nones K and Sciascia Q and McCoard SA} } @conference {69466, title = {Effect of growth hormone on the mammary transcriptome profile during established lactation in the dairy cow}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {39-42}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Gene expression profiling studies have provided insights into the potential mechanisms involved in a range of physiological processes in the ruminant mammary gland. However, despite the well established galactopoietic effect of growth hormone (GH) in lactating ruminants (Bauman, 1999; Akers, 2006), the molecular mechanism(s) that mediate the effects of GH on milk production are not fully understood.}, issn = {1176-5283}, author = {McCoard SA and Hayashi AA and Pacheco D and Sciascia Q and Nones K and Rounce JR and Sinclair BR and McNabb WC and Roy NC} } @conference {69471, title = {The effect of growth hormone on translation initiation and elongation in liver and skeletal muscle tissue in the lactating dairy cow}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {62-64}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Administration of bovine growth hormone (GH) has been shown to increase milk production in dairy cows by coordinating the metabolism of various organs and tissues, so that nutrients are repartitioned to the mammary gland to support increased requirements for milk synthesis (Keys et al., 1991). Some of the targets for GH are adipose tissue (Gallo et al., 1990), skeletal muscle, liver (Bush et al., 2003) and the mammary gland (Hayashi et al., 2009). In muscle GH decreases glucose uptake and increases amino acid catabolism efficiency (Vallimont et al., 2001), whilst the liver responds by increasing the rate of basal gluconeogenesis through lypolysis of adipose reserves (Gallo et al., 1990).}, issn = {1176-5283}, author = {Sciascia Q and Pacheco D and McCoard SA} } @conference {69519, title = {Effect of lipid type, selenium and vitamin E on total tract nutrient digestibility in growing pigs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {266-268}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {It has been shown that the fatty acid, selenium and vitamin E content of pork can be modified by dietary inclusion of different types of fat and/or supplementation with selenium and vitamin E (Morel et al.,2008). These dietary manipulations result in pork with an enhanced nutritive value. It is generally assumed that fat digestibility increases as the ratio of unsaturated to saturated fatty acids increases (Wiseman et al.,1998). However, it is not well documented how the addition of dietary antioxidants like selenium and vitamin E will affect nutrient digestibility.}, issn = {1176-5283}, author = {Nuijten WGM and Morel PCH and Purchas RW} } @conference {69499, title = {Effect of litter weight variation on cause of death and survival in triplet lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {175-179}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Triplet litter weight variation and association with lamb death and ewe age was investigated. Litter weight percentage for each lamb was calculated (PLWT). The mean and standard deviation of PLWT were used to rank lambs as Light (Mean + 1 SD). Average probability of viability at birth and death by dystocia or starvation exposure changed with weight rank. Viability at birth was Light 89.3\%, Confidence interval (CI) 87.5\% - 90.8\%; Medium 95.6\%, CI 95.1\% - 96.1\%; Heavy 98.0\%, CI 97.4\% - 98.5\%, (P <0.001). Death due to dystocia was Light 8.9\%, CI 7.2\% - 10.8\%; Medium 3.4\%, CI 2.9\% - 4.0\%; Heavy 2.1\%, CI 1.6\% - 2.8\%, (P <0.001). Death from starvation exposure was Light 5.9\%, CI 4.8\% - 7.4\%; Medium 3.7\%, CI 3.0\% - 4.5\%; Heavy 1.3\%, CI 0.8\% - 2.1\%, (P <0.01). Ewe litter weight variation (EwePLVar) was calculated as weight range divided by total litter weight. Older ewes had less EwePLVar than two-year-old ewes (P <0.01). EwePLVar and average litter weight (AveLWT) affected litter survival (EwePLVar at birth, (P <0.001), birth to Day 3 (P <0.01). Average litter weight at birth (P <0.05), birth to Day 3 (P <0.01) and Day 3 to weaning (P <0.001)).}, issn = {1176-5283}, author = {Mathias-Davis HC and Yuan JV and Everett-Hincks JM} } @conference {69479, title = {Effect of nutrition around the time of breeding and during pregnancy on yearling liveweight change, pregnancy loss and liveweight and survival of of their offspring}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {91-95}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {This experiment investigated the effects of differing nutritional levels on yearling pregnancy loss, and the live weight and survival of their offspring to weaning. Yearlings were offered either Medium or Ad-libitum levels of herbage from four days prior to breeding (P-4) until P145. Nutrition during pregnancy had no effect on pregnancy loss or lamb live weight from Day 0 of lactation (L0) until L55. Lambing percent was higher (P <0.05) in the Ad-libitum treatment compared to the Medium treatment. Single born lambs were heavier (P <0.05) than twin born lambs at L0 and at L55. Ad-libitum treatment yearlings were heavier (P <0.05) than Medium treatment yearlings at L55. Modelling of the live weight trends indicated that from P-4 until P145 the pregnant yearlings in the Medium and Ad-libitum treatment groups consumed 8.1 and 14.4 kg DM/kg of lamb live weight at L55. This indicates that the greater yearling live weight gain in the Ad-libitum group utilised more herbage during the yearling{\textquoteright}s first winter without any increase in the performance of their offspring. The extra 9 kg gained by the yearlings fed Ad-libitum may have positive effects on future performance as they will gain a suitable live weight for breeding as a two year old earlier.}, issn = {1176-5283}, author = {Mulvaney FJ and Morris ST and Kenyon PR and West DM and Morel PCH} } @conference {69488, title = {Effect of twinning and sex on carcass weight and composition in lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {133-136}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Lamb producers are being provided with strong incentives to gain better control over the growth performance of their animals. These incentives are driven by increased demand for lean product of consistent quality, rigid market specifications, and significant penalties when carcasses do not meet the criteria imposed by processors. Feed conversion efficiency is enhanced whenthe ratio of lean to fat deposition is improved (Sillence, 2004). This is an important consideration for producers due to rising costs of generating high quality feed. Hence, increasing the proportion ofcarcasses that meet market specifications can improve the profitability of a lamb-production enterprise.}, issn = {1176-5283}, author = {McCoard SA and Koolaard J and Charteris A and Luo D} } @conference {69463, title = {Effect of white clover containing high or low concentrations of water-soluble carbohydrate on metabolic indicators of protein degradationin the rumen of dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {23-28}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {White clover has high nutritive value, but contains excess protein relative to energy, leading to the wasteful excretion of nitrogen (N) by animals. Five cycles of divergent selection has resulted in white clover lines having high (HS) or low (LS) concentrations of water-soluble carbohydrate. A grazing trial was carried out to evaluate the effect of this selection on protein utilization, using skatole and indole concentrations in the milkfat as metabolic indicators for nitrogen utilisation in the rumen. Skatole and indole arise in the rumen from the degradation of the amino acid tryptophan, and rapidly accumulate in milkfat of lactating animals fed diets rich in soluble and degradable protein. Skatole and indole concentrations were both significantly (P <0.001) lower in cows fed HS clover (356 and 84 ng/g milkfat for skatole and indole, respectively) compared to those fed the LS white clover diet (800 and 420 ng/g milkfat, respectively) suggesting protein utilisation of the HS clover was improved. Although not statistically significant in this short-term study, the trends to lower concentrations of milk urea-nitrogen and urinary-N, and the nitrogen:creatine ratio for the HS clover were in the direction expected and warrant further investigation under longer-term feeding.}, issn = {1176-5283}, author = {Higgs RJ and Cosgrove GP and Burke JL and Lane GA and Pacheco D and Fraser K and Death AF and Ford JL} } @conference {69478, title = {Effects of birth rank and yearling lambing on long-term ewe reproductive performance}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {88-90}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {This experiment investigated the effects of differing nutritional levels on yearling pregnancy loss, and the live weight and survival of their offspring to weaning. Yearlings were offered either Medium or Ad-libitum levels of herbage from four days prior to breeding (P-4) until P145. Nutrition during pregnancy had no effect on pregnancy loss or lamb live weight from Day 0 of lactation (L0) until L55. Lambing percent was higher (P <0.05) in the Ad-libitum treatment compared to the Medium treatment. Single born lambs were heavier (P <0.05) than twin born lambs at L0 and at L55. Ad-libitum treatment yearlings were heavier (P <0.05) than Medium treatment yearlings at L55. Modelling of the live weight trends indicated that from P-4 until P145 the pregnant yearlings in the Medium and Ad-libitum treatment groups consumed 8.1 and 14.4 kg DM/kg of lamb live weight at L55. This indicates that the greater yearling live weight gain in the Ad-libitum group utilised more herbage during the yearling{\textquoteright}s first winter without any increase in the performance of their offspring. The extra 9 kg gained by the yearlings fed Ad-libitum may have positive effects on future performance as they will gain a suitable live weight for breeding as a two year old earlier.}, issn = {1176-5283}, author = {Morel PCH and Wickham JL and Morel JP and Wickham GA} } @conference {69500, title = {Effects of restricted fetal nutrition in utero on mTOR signaling in ovine skeletal muscle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {180-182}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {High prolificacy (twins and triplets) is a desirable trait in sheep under intensive management systems. However, multiple-born lambs have lower birth weights resulting from placental insufficiency (McCoard, 1997), and carryover detrimental effects on lean deposition, feed efficiency, and lifelong performance compared to singletons (Greenwood et al., 1998; De Blasio et al.,2007), suggesting differential nutritional programming in utero.}, issn = {1176-5283}, author = {Sciascia Q and Pacheco D and Bracegirdle J and Berry C and Kenyon PR and Blair HT and Senna Salerno M and Nicholas G and McCoard SA} } @conference {69496, title = {Effects of road transport, including stationary periods on environmental conditions and physiological responses of sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {162-164}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Livestock transport exposes animals to challenging environmental conditions that can result in welfare compromise. During road transport, sheep can be exposed to a high temperature in combination with a high humidity, expressed as a temperature-humidity index (THI), that can lead to thermal stress (Fisher et al., 2002; Fisher et al., 2004). In practice, these conditions can result in mortalities. Lambs are particularly susceptible. Extreme conditions are more likely to occur on journeys where there is little air movement through the stock crates. For example, during an inter-island ferry crossing, when vehicles carrying livestock are parked inside the hull of the ferry rather than on the outside deck (Fisher et al., 2004).}, issn = {1176-5283}, author = {Stewart M and JR Webster and Matthews LR and Rogers AR} } @conference {69524, title = {The efficacy of a herbal drench treatment on internal parasites in lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {283-284}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Internal parasites reduce live weight gains and are a cause of diarrhoea in growing lambs (Macchi et al., 2001). A challenge to organic sheep production is the control of internal parasites without intervention using synthetic chemicals. Whilst in conventional sheep production systems anthelmintic resistance to synthetic chemicals is increasing (Pomroy, 2006). The development of an effective herbal worm drench that can be commercialised will allow the organic sheep sector to develop and may offer an alternative for conventional systems.}, issn = {1176-5283}, author = {Hutton P and Scott I and Schreurs NM and West DM} } @conference {69474, title = {Evaluation of sensors for monitoring rumen pH, temperature and pressure}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {71-76}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Electronic intra-ruminal sensors and telemetry offer new opportunities for remote monitoring of the rumen environment. Sensors capable of measuring pH, temperature and pressure were subjected to laboratory and intra-ruminal evaluation in rumen-fistulated cows offered baleage indoors or hay with pasture outdoors. Each bolus underwent a testing sequence consisting of i) bench-top calibration against certified devices, ii) testing in the rumen to validate sensor measurement against actual measurement, and iii) monitoring the rumen environment of cows under contrasting feeding conditions for periods up to 72 hours. Bolus efficacy was evaluated from the accuracy of temperature and pressure measurements, stability of pH measurements over several days and the data capture rate being the actual number of data transmissions received as a proportion of the number expected based on transmission frequency setting. Intra-ruminal records show clear relationships of pH with diet and feeding bouts, whilst temperature records indicated drinking. Pressure changes were more difficult to interpret but may indicate satiety. These devices provide non-disruptive monitoring of rumen parameters and would be useful for studies of nutritional manipulation and rumen digestion efficiency, and for monitoring aspects of animal health.}, issn = {1176-5283}, author = {Lin X and Pacheco D and Kemp PD and Waghorn GC and Cosgrove GP} } @conference {69485, title = {Factors affecting dressing-out percentage of lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {121-126}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {The trial objective was to determine if hot carcass dressing out percentage (DO\%) calculated as hot carcass weight/live weight, differed with either lamb pre-slaughter live weight (SlLW) or total tissue depth over the 12th rib (GR) and to identify other factors altering DO\%. Data from ten experiments showed that SlLW only accounted for small, and measured GR moderate, amounts of variation in DO\%. DO\% was increased; by increasing the pre-slaughter fasting time; by increasing pasture allowance and by feeding more digestible forages such as clover, chicory or plantain versus grass based pasture. Similar trends occurred with the relationship between GR and DO\%. At the same SlLW wether lambs had a lower DO\% than female lambs but at the same GR there were no gender differences. At the same SlLW and GR, faster growing lambs had a lower DO\%. While many factors significantly altered DO\% including SlLW or GR, large amounts of variation in DO\% remained unexplained.}, issn = {1176-5283}, author = {Litherland AJ and Dynes RA and Moss RA} } @conference {69492, title = {Factors influencing gestation length and interval from foaling to conception in mares managed on a commercial Thoroughbred studfarm}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {146-148}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {The gestation length of mares is typically accepted as 335 to 342 days, but may range from 300 to 400 days. Most studies examining factors that may affect gestation length have been conducted in the Northern Hemisphere where foaling management may be markedly different from routine management in Australasia, where foaling takes place outdoors at pasture, and mares are kept at pasture year-round.}, issn = {1176-5283}, author = {van Rijssen JD and Gee EK and Rogers CW and O{\textquoteright}Brien JR} } @conference {69514, title = {Genetic analysis of incidence of clinical mastitis in New Zealand dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {246-249}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {The aim of the study was to estimate breed and geneticeffects on the incidence of clinical mastitis (CM) in New Zealand dairy cattle. Records of CM collected during seasons 2005-06 to 2008-09 from 53,419 cows of different breeds including Holstein-Friesian (H-F), Jersey (J) and Crossbed (HF x J), were analysed. Clinical mastitis was coded {\textquotedblleft}1{\textquotedblright} for cows that presented at least one event of CM at any day at risk during the season and {\textquotedblleft}0{\textquotedblright} for cows without CM. Genetic parameters and breed effects for the incidence of CM were estimated with a repeatability animal model across breeds using restricted maximum likelihood methodology. The cumulative lactation incidence of CM was 11\% in92,961 lactations. Heritability and repeatability for incidence of CM were 0.015 {\textpm} 0.003 and 0.070 {\textpm} 0.005, respectively. Jersey cowshad 2.9\% less incidence of CM than H-F cows. Heterosis effect of H-F x J was minus 11.7\% of the average of the parental breeds. Results from this study confirm previous estimates ofgenetic parameters for CM. Sire variation and breed and heterosis effects were significant and can be exploited in a breeding program to improve resistance to CM in New Zealand dairy cattle.}, issn = {1176-5283}, author = {Jury K and Lopez-Villalobos N and Spelman RJ and Arias J and Heuer C} } @conference {69497, title = {Genetic and environmental relationships between liveweight change over the summer in Perendale ewes and the lifetime live weight profiles of their progeny}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {165-170}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Multi-generation data from 1985 to 2002 were analysed from a 200-ewe Perendale flock to investigate genetic and environmental relationships between ewe pre-mating liveweight change and live weight of their progeny at birth, weaning, and 1, 2, 3, 4 and 5 years of age. The flock was managed at Whatawhata Research Centre and then at Winchmore Research Station, with selection for either increased or decreased wool bulk at one year of age. A total of 162 rams were used in a single-sire system. Numbers of resulting dam-offspring pairs ranged from 3,510 for progeny birth weights, to 369 for daughter 5-year-old live weights. Genetic and environmental correlations of progeny trait on dam trait, and the derived genetic (bG) and environmental (bE) regressions, were obtained from a restricted maximum likelihood animal model with a relationship matrix, after adjustment for known fixed effects. The bG estimates were all non-significant, with 14 of the 20 estimates tending to be negative. Three of the 20 estimates of bE were significant, with values ranging from 0.7 to 1.3\% of mean progeny weight per kg dam gain. The estimated environmental relationships were of insufficient magnitude to impact on the flock{\textquoteright}s productivity in the short term.}, issn = {1176-5283}, author = {Sumner RMW and Morris CA and Hickey SM and Sheppard AM} } @conference {69509, title = {Identification of novel wool keratin intermediate filament genes in sheep skin}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {222-228}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Keratin intermediate filament (KIF) genes encode key proteins for hair and wool formation. A total of 17 expressed human KIF genes involved in hair formation are annotated. However, to date, only eight wool KIF genes have been reported. In this study, six new cDNA sequences (KRT32, KRT33B, KRT34, KRT39, KRT40 and KRT82) representing previously unreported wool KIFs were identified using a contiguous ovine sequence library constructed primarily from ESTs. The expression of three other KIF genes (KRT36, KRT84 and KRT87) was confirmed by PCR using sheep skin total RNA. The analogue of human KRT37 (type I) was unable to be identified, while KRT87 (type II) was present in sheep but not in humans. Therefore 10 type I and seven type II KIF family members have been identified in sheep in comparison to 11 and six KIFs in the human. These 17 KIF genes are likely to represent the complete or near-complete set involved in wool formation. The annotation of these genes will facilitate investigation into their patterns of expression in wool follicles and their roles in the determination of fibre attributes.}, issn = {1176-5283}, author = {Yu Z-D and Gordon SW and Wildermoth JE and Wallace OAM and Nixon AJ and Pearson AJ} } @conference {69529, title = {Improving the power of activity-based heat detection using additional automatically captured data}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {299-302}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {The purpose of this study was to determine the current performance of activity monitoring devices on New Zealand pasture-based farms and investigate the potential for improved detection using additional automatically captured data. The data consisted of heat events that were assigned from pregnancy diagnosis and mating records, and from milk progesterone levels collected twice weekly during mating period. Daily milk production, milking order, milk flow rate and milk conductivity records were also collected during the mating period. The best single predictor of oestrus was 24 hour milk yield difference (P <0.01) for Herd 1 and normalised milking order (P <0.01) for Herd 2. The normalised pedometer data was the next best predictor of oestrus in both herds (P <0.01). A linear logistic regression model was fitted within each herd. The best model included normalised milk production, milking order, milk flow rate and pedometer variables. Machine learning models with balanced bagging were also fitted to the data. The machine learning models provided a better fit than traditional statistical models. Pedometer data can aid in the detection of cow oestrus, however the power of detection improves significantly with the addition of milk yield, milk flow and milking order data.}, issn = {1176-5283}, author = {Harris BL and Hempstalk K and de le Rue BT and Jago JG and McGowan JE} } @conference {69521, title = {Influence of conditioning temperature on pellet quality and the performance and nutrient utilisation of broilers fed maize- and sorghum-based diets}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {272-274}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Improved performance of broilers offered pelleted diets is thought to be due to improved nutritional value, decreased feed wastage, lowered energy expenditure during ingestion and decreased ingredient segregation (Behnke, 1994). The influence of pelleting, however, depends on the conditioning temperature used. While moderate thermal treatment of broiler diets improve the nutritional value, high conditioning temperatures can destroy vitamins and heat-labile amino acids, reduce the availability of starch by the formation of resistant starch and lower the availability of lysine through the Maillard reaction (Silversides \& Bedford, 1999). Published data on the influence of conditioning temperature on the performance and nutrient utilisation of broilers are limited. The objectives of the present experiment were to compare the interaction between two grain-based diets and conditioning temperature on the performance and nutrient utilisation of broiler starters and on the quality of pellets.}, issn = {1176-5283}, author = {Abdollahi MR and Ravindran V and Ravindran G and Wester TJ and Thomas DV} } @conference {69533, title = {Influence of management techniques on the levels of mastitis in an organic dairy herd}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {316-318}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {n 2001, Massey University set up its Dairy Cattle Research Unit (DCRU) as a system comparison between organic and conventional farming. It is the only comparative grassland-based open grazing dairy study in the world. The DCRU was split into two similar farmlets; an organic unit of 20.4 ha carrying about 46 cows (2.27 cows/ha) and a conventionally farmed unit of 21.3 ha carrying about 51 cows (2.39 cows/ha). Each of the two units is managed individually according to {\textquotedblleft}best practice{\textquotedblright} for its particular type of management system. No attempt is made to replicate on one farm what is done on the other. The project has been described in detail by Kelly et al. (2006).}, issn = {1176-5283}, author = {Thatcher A and Petrovski KR and Fraser K} } @conference {69459, title = {The influence of sheep and cattle on the grazing preference of red deer}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {3-7}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Two experiments examined the effect of sheep and cattle on the grazing preference of red deer. In the first experiment deer initially showed a significant (P <0.01) preference to graze on areas of ryegrass/white clover previously grazed for six weeks by cattle (77\% of observations) rather than by sheep (23\% of observations). However, 14 days later, deer grazing was equally distributed between cattle- and sheep-grazed areas (52\% and 48\% of observations respectively). In a second experiment deer, on pastures grazed by deer, showed no preference to graze close to cattle (48\% of observations) or sheep (52\% of observations). The strong but shortlived preference of deer for areas previously grazed by cattle cannot be explained by botanical composition, because although cattle-grazed areas contained a higher percentage of clover (22\% with cattle, 16\% with sheep), this difference was maintained for the later observation period when there was no difference in deer grazing preference. We conclude that any short-term preference shown by deer to graze with cattle rather than sheep is more likely to be due to their respective faeces/urine than their respective presence.}, issn = {1176-5283}, author = {Foote SA and Nicol AM and Ridgway MJ} } @conference {69520, title = {Influence of whole maize feeding on the performance of broiler starters}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {269-271}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Feed represents the major cost of poultry production, constituting up to70\% of the total. Feeding of whole grains to poultry has received much attention in recent years as an alternative management practice to reduce the feed cost through savings in the cost of grinding and handling and processing of grains. This mode of feeding has not only shown positive effects on the performance but it also meets the consumer demands for a {\textquotedblleft}natural{\textquotedblright} feeding system and improved animal welfare (Gabriel et al., 2007).}, issn = {1176-5283}, author = {Singh Y and Wester TJ and Ravindran G and Ravindran V} } @conference {69504, title = {Intracellular concentrations of free amino acids are reduced in skeletal muscle of late gestation twin compared to single fetuses}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {199-201}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {A cost-effective way toincrease productivity measured as kg lamb weaned per ewe, from sheep farming is to increase lambing percentage. However, late fetal and early neonatal twin lambs have reduced body weight (McCoard et al., 2000) and ~20\% less skeletal muscle mass than singletons (McCoard et al.,2001) with carryover effects on post-natal growth performance (Afolayan et al.,2007; De Blasio et al.,2007), and thus profits. Increased knowledge of the impact of nutrition and other environmental factors on the mechanisms regulating fetal growth, in particular skeletal muscle growth, is essential in order to develop new strategies to enhance meat production performance.}, issn = {1176-5283}, author = {Pacheco D and Treloar BP and Kenyon PR and Blair HT and McCoard SA} } @conference {69472, title = {Investigation of N isotopic fractionation in dairy cows using milk samples collected at the morning and afternoon milkings}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {65-66}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Conversion of feed protein into milk protein is a basis of sustainable dairy production systems from both economic and environmental perspectives. This project addresses the need for rapid screening tools to support nutritional and breeding strategies to improve the efficiency of converting feed into milk protein. The approach is based on the phenomenon of N isotopic fractionation, whereby N sinks become relatively enriched or depleted in 15N, as a result of differential incorporation during various biochemical reactions. Macko et al. (1986) showed that N isotopic fractionation was related to the deamination and transamination of amino acids. Sick et al. (1997) conducted a feeding experiment with rats and found that plasma protein was enriched and plasma urea was depleted in 15N relative to the diet. Furthermore, Robbins et al}, issn = {1176-5283}, author = {Cheng L and Dewhurst RJ and Larkin J and Buckley F and Thackaberry C and Nicol AM and Edwards GR} } @conference {69534, title = {Jim Peterson: {\textendash} A career in reproductive biology}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {319-331}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Our collaboration was both long and successful with a total of 39 publications as co-authors over a period of 32 years. Our first paper was in 1973 and our last in 2005. The collaboration was successful because it combined Jim{\textquoteright}s unique and pioneering ability to develop hormone assays with my knowledge and experience in reproductive physiology. It resulted in a number of seminal papers containing new knowledge that was then used by workers nationally and internationally to increase the understanding of hormones, their effects and interactions.}, issn = {1176-5283}, author = {Back P and Smith JF and Welch RAS and Macmillan KL and Ledgard AM and Peterson AJ and Tervit HR} } @conference {69462, title = {Lack of effect of hot summer conditions in Canterbury on milk production of dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {19-22}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {The occurrence of hot weather in Canterbury over 90 days during the 2008/2009 summer provided an opportunity to investigate the effects of climatic heat challenge on milk production by cows on commercial dairy farms in that region. An analysis of daily milksolids production and the peak temperature-humidity index (THI) recorded on each previous day was conducted for 13 farms in mid-Canterbury using data from 1 December 2008 to 28 February 2009. There were 19 days when dry bulb air temperature exceeded 27{\textdegree}C and the THI was 72 or higher, conditions at which heat stress has been suggested to occur in dairy cows. However, there was no significant inverse relationship between THI and milksolids production (P ranged from 0.193 to 0.897) on any of the farms using either all the data or only the data for days on which THI exceeded 72. With relative humidity being strongly inversely related to dry bulb temperature in Canterbury summers, THI values rarely exceed 75 in this region. As there were no discernable effects on productivity of these dairy cows during the episodes of hot weather, it is also unlikely that there would be any animal welfare concerns that could be attributable to climatic heat challenge in these conditions.}, issn = {1176-5283}, author = {Laird FC and Barrell GK} } @conference {69495, title = {Management and exercise of Thoroughbred yearlings during preparation for yearling sales in the North Island of New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {157-161}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {A cross-sectional survey was conducted to describe the management and exercise regimen at stud farms during preparation for the 2008 national yearling sales. A total of 1,166 yearlings were included in the survey, representing 82\% of those offered at the Karaka sales in 2008. Ninety-two percent of farms (69/75) used a combination of both pasture turnout and stabling during yearling preparation, with most farms (47/75; 63\%) giving yearlings access to pasture for >12 hours per day. Controlled exercise was performed on 80\% (60/75) of stud farms, with most (54/60; 90\%) farms exercising at walk. Management practices appeared to be relatively homogeneous across the farms surveyed. The provision of free exercise at pasture and controlled exercise were common practices during a sales preparation.}, issn = {1176-5283}, author = {Bolwell CF and Rogers CW and Firth EC and French NP} } @conference {69501, title = {Marbling produced in yearling heifers of Angus origin finished over a medium-term period on a high energy pasture}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {183-188}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {This study provides baseline information on the level of marbling that can be produced from yearling heifers of Angus origin when finished over a medium-term, 169 day, period on a high energy pasture. Two groups of heifers were tested, which included 30 Angus x Jersey heifers and 26 straight-bred and cross-bred (mainly Hereford x and Friesian x) Angus heifers. The daily live weight gain of the heifers during finishing averaged 788 g/d and did not differ between the two groups of heifers studied (P >0.05). At slaughter, the carcass weights of the Angus x Jersey heifers were lighter than the group of straight-bred and cross-bred Angus heifers (P <0.05). Nevertheless, both groups produced average striploin marbling scores of 2 on the Japanese Meat Grading Association 12 point scale (P >0.05), with 39\% of the cattle achieving scores >=2. The high level of variability in marbling across both groups of heifers indicated that the average level of marbling achieved could be further improved by using some predictor of marbling performance to select animals to be finished in the pasture-based system. All of the heifers produced very tender beef with average shear force values <5 kg F.}, issn = {1176-5283}, author = {Wall AJ and Rosenvold K and Archer JA and Dobbie P and Scott I and Stevens DR and Littlejohn RP} } @conference {69512, title = {Measurement of sole thickness and distance to distal phalanx using a portable ultrasound machine}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {240-242}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Using a high specification ultrasound machine, with the ultrasound transducer applied to the sole surface, Kofler et al.(1999) were able to estimate sole and soft tissue thickness in claws from bovine cadavers. These ultrasound estimates were significantly correlated with measurements, made using mechanical callipers,of the same parameters in claws after sectioning. Moreover, Kofler et al.(1999) demonstrated that it was possible to image the internal structures of the bovine claw in the live animal and also reported the use of a portable ultrasound. They did however state that the images were of lower quality, due to the poorer resolution of the transducer, and were more difficult to obtain. In contrast, van Amstel et al.}, issn = {1176-5283}, author = {Laven LJ and Margerison JK and Laven RA} } @conference {69528, title = {Methods of delivering salt to cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {296-298}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Urine from farmed livestock contributes significant quantities of nitrate nitrogen (N) to water bodies, resulting in elevated phytoplankton and nuisance plant growth. Heavily nitrate-contaminated groundwater can impair animal and human health. Ammonia and nitrous oxide also emit from urine patches, especially in anaerobic soil conditions (Ledgard and Luo, 2008). Several N leaching mitigation treatments are being evaluated in the Lake Taupo catchment (Ledgardet al., 2007) with salt, fed as a diuretic to cows during winter, showing most promise in modelling research (Bryantet al., 2007). This is probably because leaching losses from urine patches decrease exponentially as the load of N in urine patches decreases (Ledgard, 2001).}, issn = {1176-5283}, author = {Costall DA and Betteridge K} } @conference {69482, title = {Milestones in genetic prediction for applied livestock improvement}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {104-112}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Realised rates of genetic improvement depend upon structural, technological, economic and cultural factors. The potential nature and rate of genetic improvement of livestock has largely been dictated by accuracy of the predicted genetic merit of selection candidates. Major milestones in predicting merit include the use of objective measurements rather than visual appraisal; adjustment of measured performance for nongenetic factors; use of aggregate measures of economic merit for multiple trait selection; combining of information from all available sources of relatives and traits; and properly accounting for previous selection. Despite these advances, use of pedigree and performance information has major limitations. Genomic technologies can trace inheritance of chromosome fragments and with knowledge of the fragment values can improve accuracy of prediction in young selection candidates. Current genomic methods perform more poorly with real than with simulated data, and predictive abilities erode when applied to target animals not closely related to the population used to quantify fragment values. Several strategies are being investigated to improve genomic predictions, but in the meantime the principal benefit of the technology has been to increase accuracy of predicted merit of young selection candidates for routinely measured traits. In some cases this has reduced the generation interval.}, issn = {1176-5283}, author = {Garrick DJ} } @conference {69467, title = {Natural variation in levels of Immunoglobulin A in bovine milk}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {43-45}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Bovine milk has been reported to contain low levels of Immunoglobulin A (IgA) in comparison to human milk (0.1 g/L vs 1.0 g/L, respectively) (Butler, 1999). However, analysis of milk collected from cows vaccinated to induce antigen-specific IgA secretion in milk (Hodgkinson, et al., 2007) has demonstrated that the IgA response of individual cows is variable, with a ~10-fold range in the IgA production by individual vaccinated cows at peak lactation (E.A. Carpenter, Unpublished data). Approximately 10\% of these cows are classified as {\textquotedblleft}high milk IgA producers{\textquotedblright}, defined by Wagter et al.(2000) as those cows with a milk IgA concentration greater than one standard deviation above the group mean.}, issn = {1176-5283}, author = {Carpenter EA and Hurford DR and Hickey SM and Morris CA} } @conference {69483, title = {On-farm ewe lamb mating outcomes from feeding practices before mating and during pregnancy}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {113-117}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Farmers in southern New Zealand identified areas where knowledge was needed to improve the outcomes from mating ewe lambs at seven months of age. Anecdotal evidence suggested that ewe lambs growing rapidly at mating were less likely to become pregnant. Farmers recorded ewe lamb live weight in March and late May, and pregnancy diagnosis data. Data analysis showed no relationship between liveweight gain and number of ewe lambs pregnant. Farmers retained their original views that liveweight gain before and during mating should be below 100 g/d. Feeding levels in late pregnancy were considered to influence ease of lambing and lamb survival. The amount of feed offered to ewe lambs in late pregnancy on eight farms was compared to tailing percentage and lamb mortality. Feed offered to single bearing ewe lambs in late pregnancy ranged from 0.75 to 1.6 kg dry matter/d. Late pregnancy feed allowance and lamb mortality were unrelated. Analysis of winter liveweight gain data from both on-farm studies and survey results over two years showed that winter liveweight gains of 10 to 14 kg, including conceptus weight, minimised lamb losses (P <0.05). Farmers changed management practices to improve winter liveweight gain, and improve the accuracy of late pregnancy feed allocation.}, issn = {1176-5283}, author = {Stevens DR} } @conference {69489, title = {An overview of the New Zealand Thoroughbred industry}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {137-139}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {The New Zealand thoroughbred industry is internationally-competitive in terms of performance; however, the current economic situation means that the foal crop is declining. Stakes have increased in recent years but increasing costs that are common to all primary industries are also a key issue for the breeding and racing industry.}, issn = {1176-5283}, author = {Fennessy PF} } @conference {69464, title = {Phenotypic relationship between milk protein percentage and reproductive performance in three strains of Holstein Fresain cows in Ireland}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {29-32}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {The relationship between milk protein percentage and fertility in seasonal calving, dairy cattle in Ireland was quantified using a total of 584 lactation records, collected over a five-year period from experiments comparing three strains of Holstein-Friesian cows under three different feeding systems. Logistic regression analyses showed that increased protein percentage during early lactation was positively associated with the probability of a cow becoming pregnant to its first service (P <0.05). Similarly, protein percentage during the lactation had a positive (P <0.01) association with overall pregnancy rate. The results suggest that negative energy balance in early lactation or during the whole lactation causes a shortage of glucose to the udder, this restricts the synthesis of milk protein in the udder and causes a lower milk protein percentage. During negative energy balance there is also a concurrent reduction of IGF-І, LH and oestradiol secretion, which consequently delay ovarian follicular development, and hence impairs reproductive performance. In conclusion, cows with higher milk protein percentage during early lactation have a greater likelihood of becoming pregnant earlier in the breeding season, and have a higher conception rate.}, issn = {1176-5283}, author = {Yang L and Lopez-Villalobos N and Berry DP and Parkinson T} } @conference {69468, title = {Potential benefits of low replacement rate for dairy herd production and profit}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {46-50}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {The effects of different replacement rates on the genetic gain for lactation yields of milk and milksolids (fat + protein) per cow and farm profit per hectare were evaluated using a simulation model. Three levels of replacement rate were simulated 15, 19 and 27\%, by varying the levels of involuntary culling, such as with low fertility, and voluntary culling based on production worth. The effect of selection of replacements based on breeding worth was also evaluated. In the base year, farm profit was higher for lower replacement rates. Annual genetic gain in average herd breeding values for milksolids after 20 years of using bulls of high breeding worth was higher at higher replacement rates. However, farm profit at Year 20 was still higher for a herd with a low replacement rate than for a herd with a high replacement rate. A herd with a 15\% replacement rate in combination with selection of replacement heifers based on breeding worth, achieved the highest gain in breeding values for milksolids and achieved the highest farm profit at Year 20. These results demonstrate that low replacement rate in combination with selection of high breeding worth heifers can achieve high genetic gain in both milksolids and farm profit.}, issn = {1176-5283}, author = {Lopez-Villalobos N and Holmes CW} } @conference {69476, title = {Prediction of herbage dry matter intake for dairy cows grazing ryegrass-based pastures}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {80-85}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {A model that combines theoretical and empirical equations was developed to predict daily dry matter intake (DMI) for Holstein-Friesian (HF) cows grazing ryegrass-based swards and offered differing levels of concentrate supplementation. An upper limit to potential herbage dry matter (DM) intake at grazing was set, which is the lower of three limits set by either physical (rumen fill), metabolic (energy demand) or grazing restrictions. Potential herbage DMI at grazing and the herbage allowance were then used to predict herbage DMI, of cows fed only pasture, using an empirical algorithm. If supplements are fed, substitution rate was predicted to calculate actual herbage DMI. An independent dataset, with individual herbage DMI measurements (n = 1,147) of three strains of lactating HF cows, was used to validate the model. Data within strains were averaged for every month of lactation, allowing 27 data points for validation. The fitness of the model was satisfactory, with a relative prediction error (RPE) of 0.083 and a concordance correlation coefficient (CCC) of 0.74. Herbage DMI was simulated for HF cows of different genotypes fed different levels of concentrate supplementation at different herbage allowances. The model successfully predicted herbage DMI of grazing cows under different combinations of nutritional, physiological and genetic variables.}, issn = {1176-5283}, author = {Baudracco J and Lopez-Villalobos N and Holmes CW and MacDonald KA} } @conference {69525, title = {Preference of lambs for novel pasture herbs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {285-287}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {There is strong evidence that sheep show a preference for some plant species over others (Parsons et al.,1994; Concha \& Nicol, 2000; Foster et al., 2002; Rutter, 2006; Corkran, 2009). Differences among ruminant species in forage selectivity, offers a unique opportunity to manipulate utilization of pastures. Recently, increased milk yields and higher weaning weights of lambs have been shown to occur, when grazing a mixed herb sward containing chicory (Cichorium intybus), red and white clover (Trifolium pratenseand T. repens) and plantain (Plantago lanceolata) (Golding, 2008).}, issn = {1176-5283}, author = {Pain SJ and Hutton PG and Kenyon PR and Morris ST and Kemp PD} } @conference {69491, title = {Preliminary examination of sport horse competition data for genetic evaluation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {143-145}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {A sport horse can be defined as a horse which participates in one of the three equestrian disciplines represented at Olympic level. These disciplines are dressage, eventing and show jumping. There are approximately 5,000 horses registered for equestrian sport in New Zealand (Rogers \& Firth, 2005). Despite the relatively small size of the New Zealand equestrian sport population, the New Zealand industry has been successful in International sport with the production of predominantly show jumpers and event horses for the export market (Rogers, 1993; Rogers \& Firth, 2005).}, issn = {1176-5283}, author = {Creagh FE and Hickson RE and Rogers CW} } @conference {69503, title = {Preliminary investigation of milk production in Angus heifers exposed to different nutrition in utero}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {194-198}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Milk yield (MY) and composition were measured on one day in Weeks 7, 9 and 11 in 17 offspring of Angus cows fed for high (1.2 kg/d; HB) or medium (0.5 kg/d; MB) liveweight gain (LWG) for 10 days before insemination and medium (0.5 kg/d; MA) or low (0.01 kg/d; LA) LWG during gestation. Mean MYs in the progeny were; Week 7: 5790 {\textpm} 420 g/d, Week 9: 7418 {\textpm} 447 g/d, Week 11: 6244 {\textpm} 392 g/d. Better feeding before mating had little effect on MY or milk crude protein (CP\%) in the progeny but tended to reduce the milkfat\% (Week 9; HB (n = 8) 3.50 {\textpm} 0.17\% versus MB (n = 8) 3.74 {\textpm} 0.22\%) (P <0.19), casein (Week 11; HB 2.59 {\textpm} 0.03\% versus MB 2.68 {\textpm} 0.04\%) (P = 0.11) and lactose (Week 11; HB 5.18 {\textpm} 0.13\% versus MB 5.42 {\textpm} 0.05\%) (P = 0.075). Better feeding of the dam after artificial insemination did not significantly increase MY of the progeny (Week 9; MA (n = 9) 7972 {\textpm} 378 g/d versus LA (n = 8) 6794 {\textpm} 826 g/d) (P = 0.23), or milkfat\%, decreased CP (Week 9; MA 3.22 {\textpm} 0.07\% versus LA 3.41 {\textpm} 0.08\%) (P <0.09) and casein\% (at Weeks 7 and 9 identical values of MA 2.52 {\textpm} 0.06\% versus LA 2.69 {\textpm} 0.07\%), but increased lactose\% after the peak of lactation (Week 11 MA 5.42 {\textpm} 0.06\% versus LA 5.15 {\textpm} 0.14\%) (P <0.08). Feeding before and after conception may affect the nutrition of the grand generation}, issn = {1176-5283}, author = {Peterson SW and Jenkinson CMC and Hickson RE and Morris ST and Blair HT and Kenyon PR} } @conference {69493, title = {Preliminay examination of training and racing milestones in a subset of Standardbred horses}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {149-151}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {The Standardbred (harness racing) industry is the second largest equine industry in New Zealand. In 2004 it had a total contribution to the country{\textquoteright}s gross domestic product of $327 million (IER, 2004). Of the 22 countries that participate in harness racing, New Zealand is ranked tenth based on the number of individual horses to race per season, and on the number of races run per season (Harness Racing New Zealand, Personal communication). However, despite the economic contribution of the Standardbred industry in New Zealand there has been little documentation of the structure and demographics.}, issn = {1176-5283}, author = {Tanner JC and Rogers CW and Bolwell CF} } @conference {69490, title = {The prevalence of limb deformities in New Zealand Standardbred foals and the influence on racing success - A preliminary investigation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {140-142}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Within the New Zealand racing industry, breeders and purchasers of racehorses seek foals with good conformation as racing and breeding prospects. There is a perceived association between correct conformation and the duration and success of racing careers (Welleret al., 2006a). However, to date there has been limited data on the effect of limb deformities on any parameters of racing success (Morley \& Townsend, 1997, Andersonet al., 2004).}, issn = {1176-5283}, author = {Stowers NL and Erdtsieck B and Rogers CW and Taylor TB and Firth EC} } @conference {69531, title = {Productive and reproductive performance of Uruguayan Holstein and Urugyayan Holstein x New Zealand Holstein Friesian cows in a predominantly pasture-based system}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {306-310}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {The performance of Uruguayan Holstein (UH) and UH x New Zealand Holstein Friesian first cross (UHNZHF) cows was investigated over 1 year using 62 cows offered predominantly native pasture. Accumulated 305 day yields of milk, fat, protein and milksolids (fat+protein) were not affected by the strain. The UH cows produced 0.5 L/d more milk than UH-NZHF cows at Day 240 of lactation (P <0.05). Fat and lactose percentages were greater in UH-NZHF cows (3.72 vs 3.44\% and 5.02 vs 4.94\%, respectively, P <0.0001). Protein percentages tended to be greater in UH-NZHF cows (3.31 vs 3.27\%, P = 0.08). The UH cows were 49 kg heavier (569 vs 520 kg, P <0.001) and required a greater energy requirement for maintenance. The UHNZHF cows produced more milksolids per kg of BW0.75, (P <0.01). Pregnancy rates tended to be greater in UH-NZHF cows (87 \% vs 71\%, P = 0.08) and were greater when the first 40 days of service were considered (61 vs 35\%, P = 0.04), which may be related to a differential energy partitioning according to strains.}, issn = {1176-5283}, author = {Periera I and Laborde D and Carriquiry M and Lopez-Villalobos N and Meikle A} } @conference {69518, title = {Review of pork-quality studies in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {261-265}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {This paper presents data published between 1990 and 2009 on pork quality in New Zealand. The characteristics considered are pale, soft and exudative (PSE), dark firm and dry (DFD), boar taint, intramuscular fat (IMF\%), chemical composition aspects such as fatty acids profile and flavours other than boar taint. Over the years the incidence of PSE has been reduced from 40\% to 6\%. The percentage of DFD pork was always below 7\%. A level of 2.0\% of IMF\% is considered as a minimum with respect to palatability. Between 1990 and 2009, reported values for IMF\% ranged from 0.98\% to 3.36\% and tended to decreased over time. Skatole and androstenone are the two major compounds responsible for boar taint. In New Zealand, males are slaughtered {\textquotedblleft}entire{\textquotedblright}. In 1996 only 19\% of them were below the European Community threshold for boar taint. Results from different feeding experiments show that the fatty acid profile, selenium content and flavours other than boar taint, of pork can easily be changed. Overall pork from New Zealand pigs is of a high quality, but the incidence of boar taint is of concern.}, issn = {1176-5283}, author = {Morel PCH and Purchas RW and Wilkinson BHP} } @conference {69458, title = {Role of the New Zealand Society of Animal Production in fostering collaboration}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {1-2}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {

When you sign up for a year as President of the New Zealand Society of Animal Production, you should make an attempt to understand who the Society really is, and how the members are best served by the Society. If you go back through previous Presidential Addresses some recurring themes come up around this issue of who is the Society Membership and what should the Society be doing to best serve the membership? The fact that we frequently re-visit this question shows that it is pertinent. It also proves the words of Abraham Lincoln true when he said {\textquotedblleft}Books serve to show a man that those original thoughts of his aren{\textquoteright}t very new at all{\textquotedblright}

}, issn = {1176-5283}, author = {Archer JA} } @conference {69470, title = {Ryegrass to lucerne-effects of dietary change on intake,milk yield and rumen microflora bacteria of dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {57-61}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {The value of legumes for milk production has been attributed to higher intakes by cows and a higher nutritive value compared to ryegrass. However, abrupt changes in diet can adversely affect production, even when the change is to feed with a higher feeding value. A 13-day indoor experiment compared the responses of 12 cows that were changed from ryegrass to lucerne (Medicago sativa L.) (L) on Day 4, with 12 cows remaining on ryegrass (R). Immediately after the change to lucerne there was a 24\% decrease in milk yield; this was temporary, as from four days after the change these cows averaged 20\% more milk than those fed ryegrass (L = 15.7, R = 13.1 kg milk/cow/d; P <0.001). The temporary decrease in milk yield was not due to decreased intake as lucerne-fed cows had higher intakes (L = 16.5, R = 14.8 kg dry matter/cow/d; P <0.001). Only small differences in the rumen microbial populations were apparent on the day diets changed. The temporary decrease in milk yield was more likely associated with a change in metabolism of the resident bacteria. Improved understanding of the microbial consequences of an abrupt dietary change will enable better management decisions to be made on-farm.}, issn = {1176-5283}, author = {Woodward SL and Waghorn GC and Attwood GC and Li D} } @conference {69477, title = {Simulated impacts of increased nitrogen retention in dairy cows on nitrate leaching from grazed pasture}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {86-87}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {The intensification of grazing land has increased the amount of nitrogen (N) entering waterways, reducing their quality and clarity. Between 60 and 90\% of the N ingested by grazing cattle is excreted in urine and dung (Haynes \& Williams, 1993), providing the major source of nitrate leached from grazed pasture. Reducing the N content of urine can therefore have a major impact on nitrate leaching, which can be achieved by reducing dietary N or improving N partitioning in the animal. Some techniques that improve N partitioning have been evaluated. These include dietary manipulation and the use of metabolism modifiers (Di \& Cameron, 2000).}, issn = {1176-5283}, author = {de Castro J and Bryant JR and Burggraaf VT} } @conference {69507, title = {Suitability of the Happy Factor decision support model as part of targeted selective anthelmintic treatment in Coopworth sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {213-216}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {The suitability of the Happy Factor decision support model as the determinant of a targeted selective treatment regime incorporated into an automated weighing and drafting facility was evaluated in a Canterbury environment. One hundred and twenty, six-month-old Coopworth lambs naturally infected with gastrointestinal parasites were weighed and faecal sampled every two weeks for eight weeks. Individual performance targets during each two week period were calculated using the Happy Factor decision support model. Lambs that did not reach their performance target were automatically drafted out and subsequently treated with anthelmintic. Those deemed to benefit from treatment had significantly greater faecal egg count (FEC) than their untreated counterparts at Week 4 only, were lighter on Weeks 2 and 8, but had lower liveweight gains on all four occasions. Overall, the system provided a rapid and reliable method of identifying and separating poorer performing individuals, which were not necessarily those with a high FEC or those that were lighter. Furthermore, the optimum treatment threshold was determined to be 0.74, which is greater than previously published values of 0.66 for Scottish Blackface sheep. This suggests that validation of an optimum Happy Factor treatment threshold for each environment and/or animal genotype may be required.}, issn = {1176-5283}, author = {Greer AW and McAnulty RW and Logan CM and Hoskin SO} } @conference {69475, title = {Use of novel pasture species to reduce methane emissions from New Zealand grazing ruminants}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {77-79}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {In New Zealand, methane (CH4) accounts for approximately 38\% of greenhouse gas emissions. The majority of this methane, approximately 98\%, is from ruminants (Waghorn \& Woodward, 2006). New Zealand{\textquoteright}s ruminant production industry relies heavily on a pasture-based system and depends on efficient utilisation of pasture. Variation between plant species in their nutritional and chemical composition provides an opportunity to manipulate rumen fermentation patterns and increase the utilization of pastures, while potentially reducing ruminant livestock CH4emissions. Preliminary findings are reported from a pilot study which investigated the effects of nutritional composition of a range of forage species on the short-term in vitro production of CH4.}, issn = {1176-5283}, author = {Roca FJ and Hutton PG and Pain SJ and Kenyon PR and Morris ST} } @conference {69515, title = {Variation in feed conversion efficiency in Holstein-Friesian heifer calves}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {250-252}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Feed conversion efficiency (FCE) is a measure of an animal{\textquoteright}s ability to convert feed into product and is a major determinant of profitability in livestock production. This study evaluated two determinants of FCE in Holstein-Friesian heifer calves, growth rate and residual feed intake (RFI). The improvement in FCE, measured as feed intake per unit of liveweight gain (kg/kg), associated with increased growth rate is well known (see Archer et al., 1999). It is measured when the energy costs of maintenance are relatively small compared to the energy intake that is partitioned into growth of animal tissues or lactation.}, issn = {1176-5283}, author = {Carnie KR and Davis SR and MacDonald KA and Waghorn GC and Obolonkin VV and Spelman RL} } @conference {69508, title = {Wool characteristics in the Meat and wool New Zealand Central Progeny Test flocks}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {217-221}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {The Meat and Wool New Zealand Central Progeny Test programme (CPT) was established to demonstrate the relative breeding merit of leading sires in the New Zealand sheep industry. Here we describe the wool grown over the summer by the 2007 born one-year-old ewes within the CPT. Within fleeces, staple strength varied between farms as shown by the mean difference of 23 N/ktex in offspring of the link sire. Staple strength correlated positively with midside fibre diameter (r = 0.26), medullation (r = 0.23) and negatively with fibre curvature (r = -0.61). Staple strength was similar on anterior (74 {\textpm} 24 N/ktex) and midside (75 {\textpm} 24 N/ktex) body-sites, but was weaker on the hindleg (64 {\textpm} 21 N/ktex; P <0.001). Overall mean staple strength was 72 {\textpm} 20 N/ktex, while individual fleeces ranged from 19 to 121 N/ktex. Ten percent of fleeces measured below 45 N/ktex leaving them prone to excessive fibre breakage during processing. Some fleeces varied up to 40 N/ktex across body-sites. Even within one flock, offspring of individual sires differed by a mean of 29 N/ktex, suggesting a consistent weakness of wool in the progeny of some highly ranked sires which will negatively affect processing and end-product performance.}, issn = {1176-5283}, author = {Craven AJ and Ashby MG and Scobie DR} } @conference {69480, title = {Yearling lambing performance and primary cause of lamb death}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {96-100}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {As a result of increasing on-farm costs, farmers are aiming to increase the number of saleable lambs by lambing yearling ewes. This study investigated lamb survival rates in lambs born to yearlings from birth to three days of age. Data were collected from six recorded flocks in 2007 and 2008, involving 880 yearling ewes giving birth to 557 single and 756 twin lambs. All lambs were weighed at birth and at weaning. Lambs that died within the first three days of life were subject to post-mortem to determine the primary cause of death. Mean lamb survival to three days of age was 80\% and survival to weaning was 72\%. There were significantly less twin lambs born alive, than single lambs (90\%, CI 88\% - 92\%, cf. 95\%, CI 93\% - 96\%, P <0.05). Twin lambs had a higher death rate due to starvation/exposure, (6.3\%, CI 5.3\% - 7.4\% cf. 2.8\%, CI 2\% - 3.8\%, P <0.05) than single lambs. Dystocia did not differ significantly between single and twin lambs (6\% cf. 10\% respectively; P >0.05). Mortality in the first few days after birth is higher in yearlings than in flock ewes and higher in twins than singles.}, issn = {1176-5283}, author = {Young EA and Yuan JV and Everett-Hincks JM} } @conference {69020, title = {Amino acid flow at the abomasum in twin-suckling ewes at pasture and the effect of a fishmeal supplement}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {233-237}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Fourteen twin-suckling ewes with rumen and abomasal cannulae grazed a ryegrass/clover sward (C; n = 7) or the same sward but with a 500 g/h/d protein supplement (S; n = 7). The trial was designed as a cross-over with two 14 day adaptation periods followed by two five day sampling periods (Days 43-48 and 63-68 after lambing). All ewes were treated with anthelmintic 14 days after lambing. Flow of amino acids (AA) at the abomasum and dry matter (DM) intake were measuredduring both periods using intra-ruminally infused markers. Diurnal variation in AA flow peaked between 12:00 and 15:00 h and was greatest in the supplemented ewes. Flows of AA were increased by supplementation; Essential AA, +16 \%; 128 to 148 g/d, Sulphur-AA, +21.2 \%; 3.3 to 4.0 g/d, Branched-chain AA, +15.9\%, 47.8 to 55.4 g/d. There was evidence for a lower faecal egg count in supplemented animals, being 670 vs 46 epg, respectively, in C and S groups, (P = 0.08) 21 days after anthelmintic treatment. This work provides information on the extent of enhancement of the supply of amino acids associated with ability to limit the peri-parturient increase in faecal egg count and provides a basis for the development of supplements.}, issn = {1176-5283}, author = {Madibela OR and Gibbs SJ and Sykes AR and Laporte-Uribe J and Zhao J} } @conference {60956, title = {Background effects on ewe lambing and weaning performance in well recorded breeding flocks}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {115-117}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Results of analyses of Sheep Improvement Ltd. (SIL) data (27 flocks and 128,203 lambings) showed a substantial impact of ewes being scanned pregnant but failing to rear a lamb (wet-dry), on weight of lamb weaned at the next lambing. Compared to ewes that reared a lamb at the previous lambing, {\textquoteright}wet-dry{\textquoteright} ewes had 0.3 to 0.5 less lambs born per ewe lambing, lamb survival rates were lower by 60 to 70 percentage points and weaning weights up to 0.5 kg lighter per lamb weaned. These effects compounded into 30 to 40 kg less weight of lamb weaned per ewe. The failure to rear part of a litter, such as one lamb of a set of twins, had less effect on performance at next lambing and weaning, than loss of the whole litter. Those ewes that previously gave birth to three lambs weaned 4 kg less lamb weight than ewes that previously gave birth to singles, after allowing for their higher genetic drive for prolificacy. A modest but significant effect of previous litter size was observed on weight of lamb weaned within each litter size category. Lamb survival was observed to be 2\% lower (P <0.01) for twin ewes that had failed to rear one of their two lambs, compared with those that had reared both in their previous lambing. }, issn = {1176-5283}, author = {Amer PR and Sise JA and Jopson NB and Bray AR} } @conference {69019, title = {Bioactive plants inhibit bacteria that cause lactic acidosis in ruminants : Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {230-232}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Lactic acidosis may become an animal welfare issue in New Zealand if the level of concentrates used in the feed ration increases. Lactic acidosis develops in ruminants because of the excessive production of lactic acid by starch degrading bacteria in the rumen after animals are introduced to grain{\textendash}based diets containing large amounts of starch. It is important that lactic acid is converted to volatile fatty acids in the rumen rather than being absorbed into the bloodstream. Rumen bacteria that ferment starch to lactic acid are capable of rapid cell reproduction and, when starch is freely available, produce lactic acid at a higher rate than lactate is fermented to volatile fatty acids by lactate-using bacteria.}, issn = {1176-5283}, author = {Hutton P and Durmic Z and Ghisalberti E and Duncan R and Carson CF and Riley TV and Vercoe PE} } @conference {60943, title = {Breed effects for lactoferrin concentration determined by Fourier transform infrared spectroscopy}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {60-64}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {A calibration equation based on partial least squares using Fourier transform infrared spectroscopy (FTIR) data was derived to predict concentration of lactoferrin (Lf) in bovine milk. The concordance correlation coefficient of the calibration equation was estimated at 0.81 using 246 milk samples collected in the 2003-04 season from second-parity crossbred cows during late lactation. The calibration equation was then used to predict the concentration of Lf (pLf) in 9,742 milk samples from 814 Holstein-Friesian (HF), 955 Jersey (J) and 842 crossbred HF x J cows sampled on average 3.7 times during the 2007-08 season. A repeatability animal model was used to obtain breed effects and estimates of variance components for pLf. Concentrations of pLF (mg/L milk) were significantly (P <0.001) different between breed groups (HF = 163 {\textpm} 3.8, HF x J = 175 {\textpm} 5.0 and J = 193 {\textpm} 6.3). Heritability and repeatability of pLf concentration were 0.16 {\textpm} 0.036 and 0.35 {\textpm} 0.012, respectively. These results confirm previous studies showing that Lf concentration in milk can be predicted using FTIR spectroscopy and that there are significant breed differences and animal variation that can be exploited in a breeding program. }, issn = {1176-5283}, author = {Lopez-Villalobos N and Davis SR and Beattie EM and Melis J and Berry S and Holroyd SE and Spelman RJ and Snell RG} } @conference {60961, title = {Breeding and selection goals and animal welfare}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {135-139}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Contemporary concerns with animal welfare are increasingly being expressed through reference to the Five Freedoms, paraphrased as animal needs. However, in addition to providing for the needs of livestock, breeding animals to suit the environment, especially in extensive farming systems, is an inherent quality of good stockmanship. Although most farm animal breeding goals are directed at increasing productivity, some, for example resistance to disease or ease of giving birth, also contribute to enhanced animal health and welfare. Increasingly societal expectations are shaping the practices of animal rearing and management, and more recently breeding. It is suggested that those responsible for breeding and selection acknowledge the potential animal health and welfare consequences, both positive and negative, of breeding goals. In so doing that they be prepared for the need to articulate those goals in terms of animal health and welfare, or the need for relevant animal husbandry skills and resources. Subsequently, where necessary they incorporate animal welfare objectives into their breeding programmes. In addition, animal welfare interests need to be aware of the limitations of relying solely on the Five Freedoms, or needs of animals, and acknowledge the wider aspects of good animal husbandry which contribute to animal welfare. }, issn = {1176-5283}, author = {Fisher MW and Webster AJF} } @conference {60969, title = {Current and future impact of DNA technologies on the New Zealand sheep industry}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {165-168}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {DNA technologies are already widely used in the New Zealand sheep industry. Parentage determination in extensively managed flocks is currently the most widely used test. Increasingly, these tests are being supplemented by the use of performance markers, either by themselves or in conjunction with parentage. Commercial single marker tests currently available in New Zealand include: two for meat yield, two for prolificacy, parasite resistance and production, lamb survival, footrot, scrapie susceptibility, and several monogenic trait tests including: microphthalmia, horns, and spider lamb. However, the future is likely to be some form of {\textquoteright}genomic selection{\textquoteright} where the test explains a major, perhaps majority, of the genetic variation in an animal. This technology depends on the creation and use of high density SNP (single nucleotide polymorphism) probe chips. In New Zealand dairy cattle it is expected to increase the rate of genetic gain by 50 to 70\%. A similar chip has been created for sheep and New Zealand animals are currently being genotyped. If successful the expectation is that industry release will occur in late 2009. New Zealand sheep industry delivery will be as breeding values created using a blend of DNA and existing Sheep Improvement Ltd. information. }, issn = {1176-5283}, author = {McEwan JC} } @conference {60960, title = {Dairy cows and horses do not select oaten hay based on its greenness : Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {132-134}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Domestic and export markets for oaten hay are driven largely by estimates of the quality of hay produced. This assessment is commonly based on the plant of origin and subjective criteria, such as colour, or {\textquoteright}greenness{\textquoteright}, and general appearance as judged by an observer. However, subjective measures such as these are not always reliable indicators of an animal{\textquoteright}s response to a hay when offered, in terms of its intake and ultimate performance. Understanding the role of specific plant characteristics that... Continued }, issn = {1176-5283}, author = {Pain SJ and Revell DK} } @conference {60939, title = {Delaying the time of morning grazing improves milk production in winter}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {46-50}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Herbage dry matter content and water-soluble carbohydrate influence cow intake and production. Delaying the time of grazing may increase the dry matter and water-soluble carbohydrates content of herbage and increase grass consumption and milk production. This study determines the cow response to early (8:00 h) and late (11:30 h) offer of winter pasture (Lolium multiflorum) for primiparous cows 120 days in lactation. Herbage dry matter content, grazing time and daily herbage dry matter intake increased when the time of grazing of the winter pasture was delayed (140 vs 171 g/kg dry matter (DM), 71 vs 110 minutes and 2.7 vs 4.8 kg DM/cow/d respectively; P <0.05) while the increment in the water-soluble carbohydrates content of the herbage was not significantly different between treatments (53 vs 75 g/kg DM; P = 0.09). As a consequence of the higher daily herbage dry matter intake of cows grazing winter pasture late in the morning, daily milk and milksolids production was higher than pasture offered early in the morning (29.2 vs 31.0 L/cow and 2.05 vs 2.19 kg/cow respectively; P <0.05). }, issn = {1176-5283}, author = {Acosta GA and Rossi JL and Ayala Torales A and Acosta A} } @conference {60968, title = {Developments in the sheep meat industry: Genetic evaluation of meat yield}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {161-164}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Sheep Improvement Ltd. has a {\textquoteright}MEAT{\textquoteright} Goal Trait Group which is used to select animals on their genetic merit for meat production. Breeding values are calculated for weight of carcass lean, carcass fat and carcass weight. These breeding values are estimated from live weight and ultrasonic eye muscle dimension data, with the option of incorporating computed tomography (CT) measurements. This served the sheep industry well while carcasses were graded on the basis of carcass weight and GR tissue depth. However, deregulation in the meat industry has seen individual meat processors developing carcass grading systems which not only improve estimates of lean and fat, but also estimate retail yield within individual cuts. SIL have developed a {\textquoteright}MEAT YIELD{\textquoteright} module in response to these changes which estimates breeding values for lean weight in the shoulder, loin and hindleg primal cuts. Meat yield data collected from surplus slaughtered progeny are added to live weight and ultrasonic eye muscle data to predict the breeding values. Slaughter progeny should be randomly selected to avoid biasing the meat yield data. This module is likely to be developed further as additional grading systems are implemented, and equations to translate data into standardised measurements will be required. }, issn = {1176-5283}, author = {Jopson NB and Newman S-AN and McEwan JC} } @conference {69022, title = {Differential passage of rumen bacterial populations to the abomasum in sheep : Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {242-243}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Ruminant microflora and fauna enable the degradation of otherwise poorly digestible feeds and are a principal source of metabolisable protein (Faichney, 1996). Rumen outflow, which is dependent on many factors including the physical characteristics of the diet and the level of feed intake, carries both nutrients and microorganisms to the abomasum. The proportional contribution of the various sub-populations of microorganisms to the total pool of abomasal protein is still poorly defined (Dewhurst et al., 2000). It is therefore possible that differences in motility or microhabitat between subpopulations may generate differential retention of certain groups.}, issn = {1176-5283}, author = {Laporte-Uribe J and Gibbs SJ} } @conference {60942, title = {DNA methylation events associated with the suppression of milk protein gene expression during involution of the bovine mammary gland : Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {57-59}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {During lactation, prolactin activates STAT5 (Signal Transducer and Activator of Transcription), which binds to conserved DNA sequence motifs in promoters of milk protein genes to stimulate their expression (Liu et al., 1997). At drying-off, mammary involution is characterised by a rapid decrease in milk protein gene expression (Goodman \& Schanbacher, 1991), including ?S1-casein (Singh et al., 2008). The ?S1-casein promoter features... Continued }, issn = {1176-5283}, author = {Singh K and Swanson K and Couldrey C and Seyfert H-M and Stelwagen K} } @conference {60948, title = {Do objective measurements or subjective assessments explain more of the variation in strong wool auction prices?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {80-84}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Auction prices of a total of 74,134 lots of wool in the strong wool segment of the New Zealand wool clip sold between 1 July 2005 and 30 June 2007, were analysed by multiple regression analysis to estimate the proportion of variation in wool price explained by four objectively measured characteristics and by subjective assessments of length and colour with up to five additional codes. The objective characteristics were vegetable matter content, mean fibre diameter CIE Y (brightness), and CIE Y-Z (yellowness). Changes in the New Zealand dollar exchange rate were adjusted for by covariance against the exchange rate of the US dollar on the day of the auction. The residual standard deviation for the objectively measured characteristics was 22.2 c/kg clean, explaining 80.2\% of the variation in price. In contrast, the residual standard deviation for the subjectively assessed codes identifying "outlier" lots in terms of characteristics deemed to be important by scourers and processors was 21.4 c/kg clean, explaining 81.6\% of the variation in the auction price. It will thus benefit wool growers to prepare their wool such that lots conform to the recommended best practice guidelines rather than for them to conform solely to objective specifications. }, issn = {1176-5283}, author = {Sumner RMW} } @conference {60938, title = {The effect of concentrate supplementation on milk production during an extended lactation in grazing dairy cows : Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {43-45}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Extended lactation systems where cows are milked for longer than 300 days, provide an opportunity for farmers to use the lactation potential of genetically superior cows, reduce calving and mating costs, even-out labour requirements, and/or build herd size by retaining non-pregnant cows. However, depending upon cow genetic strain and nutrition, milk production can be reduced in an extended lactation system relative to a {\textquoteright}normal{\textquoteright} lactation of 260 to 300 days (Kolver et al., 2007; Grainger et al., 2009). Winter-feeding levels are potentially important... Continued}, issn = {1176-5283}, author = {Phyn CVC and Kay JK and Roach CG and Kolver ES} } @conference {60955, title = {The effect of fasting on live weight in hogget wethers and pregnant mature ewes : Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {112-114}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Withholding of food and water, or fasting, of sheep for up to 24 hours is a practice commonly employed in the agricultural industry and research sectors. Farmers routinely fast sheep before shearing, pregnancy scanning and transport. Further, with relatively large numbers of animals involved in some experiments, duration of weighing and manipulation time can vary, which may interfere with a comparison of live weight measurements. The determination of the rate of liveweight loss will allow live weights to be corrected to... Continued }, issn = {1176-5283}, author = {Burnham DL and Morel PCH and Kenyon PR and Morris ST and Stafford KJ} } @conference {60934, title = {The effect of feed restriction during peak lactation on milk production parameters : Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {24-26}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Adverse weather conditions that reduce pasture growth and/or quality can place the lactating dairy cow under periods of transitory nutritional stress. Previous research that has focused on the effects of feed restrictions in a pasture-based dairy system have imposed feed deficits either pre-calving (Roche, 2007), immediately post-calving for five to six weeks (Bryant \& Trigg, 1979; Roche, 2007) or up to a 23\% restriction in dry matter intake (DMI) (Bryant \& Trigg, 1979). All experiments reported an immediate reduction in milk production; however, the longer-term effects varied depending on... Continued }, issn = {1176-5283}, author = {Kay JK and Phyn CVC and Williams YJ and Roche JR and Burke CR and Meier S} } @conference {60970, title = {Effect of management change on methane output within a sheep flock}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {170-173}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {The introduction of an emissions trading scheme means farmers are likely to incur some form of carbon tax on methane emissions. Consequently, it is important to explore management options that could reduce methane output per unit of product sold. A computer model was developed to test a range of management strategies on methane production, relative to farm output. These included changing ewe live weight, conception rate, scanning percentage, ewe and lamb survival, ewe culling rates, lamb growth rate, hogget lambing and ewe culling age. The dataset used to develop the model contains 6,000 ewe and 8,100 lamb records collected over 8 years. The reference flock used in the model comprised 1,000 ewes plus replacements, 1,378 lambs scanned, 989 lambs sold and 288 replacements kept. The carbon cost was 15.99 kg of methane per lamb sold. Three of the most significant influences on methane production per lamb sold were increasing ewe cull age from 5 to 6 years (4.6\% reduction), increasing ewe scanning percentage from 160\% to 180\% (7.8\% reduction) and hogget lambing (11.7\% reduction). Effects were not completely additive. The model allows methane output to be estimated for any defined production system and quantifies the most effective management changes to minimise methane production on an individual farm or across the wider industry. }, issn = {1176-5283}, author = {Cruickshank GJ and Thomson BC and Muir PD} } @conference {60952, title = {Effect of sex on colour and pH of chilled lamb loins : Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {101-103}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {With more chilled lamb being exported from New Zealand, there is interest in factors affecting the quality of the chilled product. Two key factors are ultimate pH and the redness of the meat when on display for sale. The possible effect of the sex of the lamb on these quality traits is of interest to the industry (Meat and Wool New Zealand, 2006). A number of studies have reported non-significant differences between ewe and ram lambs at moderate carcass weights of approximately 18 kg, for pH and colour measured within 24 hours post-slaughter... Continued }, issn = {1176-5283}, author = {Bain WE and McLean NJ and Young EA and PL Johnson} } @conference {60933, title = {Effect of water soluble carbohydrate concentration of ryegrass on the partial preference of sheep for clover}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {20-23}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {A trial was carried out to determine whether grass cultivar or water soluble carbohydrate (WSC) concentration would influence the partial preference of sheep for clover and ryegrass. Six mixed age Coopworth ewes were housed in individual pens and once a day offered swardlet monocultures of white clover adjacent to one of three perennial ryegrass cultivars. One swardlet of each grass cultivar was shaded and the other left un-shaded in order to create differences in WSC concentration. WSC concentration did not differ among ryegrass cultivars but was lower in shaded (210 g/kg dry matter (DM)) than non-shaded (230 g/kg DM) ryegrasses. Neutral detergent fibre was significantly higher in the un-shaded (439 g/kg DM) than non-shaded (422 g/kg DM) ryegrass (P <0.01). The total number of bites from clover swardlets fed adjacent to shaded grass swardlets was 21\% greater (P = 0.026) than when fed adjacent to non-shaded grass swardlets. Sheep took a significantly lower proportion of bites from clover when paired with un-shaded (44\%) than shaded (55\%) ryegrass (P = 0.03). There were no significant effects of ryegrass cultivar on any aspect of the preference tests. The results of this work support the hypothesis that partial preference for clover can be manipulated by altering the WSC concentration of companion ryegrass by shading but not, in this case, by ryegrass cultivar. }, issn = {1176-5283}, author = {Allsop ARC and Nicol AM and Edwards GR} } @conference {60945, title = {The effect of weaning at 10 or 14 weeks of age on liveweight changes in the hogget and her lambs : Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {68-70}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Kenyon et al. (2004) revealed via a survey, that a major reason why New Zealand farmers do not breed ewe hoggets (7-9 months old) is perceived detrimental effects on two-tooth breeding live weight, resulting in reduced two-tooth reproductive performance. Kenyon et al. (2008) confirmed this by showing hoggets that lambed had reduced two-tooth live weight and condition score at breeding. A potential means of minimising any potential negative effects on... Continued}, issn = {1176-5283}, author = {Mulvaney FJ and Morris ST and Kenyon PR and West DM and Morel PCH} } @conference {60947, title = {Effects of birth weight on survival in twin born lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {75-79}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Lamb survival to weaning decreases as litter size increases (single > twin > triplet > quads), with birth weight being a major factor affecting survival. The purpose of the present study was to investigate the effects of birth weight (BWT) and related traits on survival in twin born lambs. Data from a total of 3,834 twin lambs born to mixed aged ewes were analysed. For statistical analysis the lambs were allocated according to birth weight (BWT) within litter to three groups (Light = Lightest lambs within pairs, Equal = Lambs of similar weight within pairs and Heavy = Heaviest lambs within pairs). The survival rates differed (P <0.05) between Light, Equal and Heavy (80\%, 89\% and 83\%, respectively). BWT was positively related (P <0.001) to survival in the Light group, but not in the other two groups. The smaller the difference in BWT between siblings, the higher the likelihood of the Light lambs surviving. Therefore, reducing the difference in BWT within a set of twins will have the potential to increase overall lamb survival. }, issn = {1176-5283}, author = {Morel PCH and Morris ST and Kenyon PR} } @conference {69021, title = {Effects of high potassium on in vitro fermentation pattern and C18 fatty acid metabolism of pasture grass}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {238-241}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {The effect of high potassium concentration on rumen fermentation and fatty acid biohydrogenation (BH) were investigated in a 6 hour in vitroincubation. A pasture grass sample with 26.3 g/kg dry matter (DM) of potassium was used as control. Supplemental levels of 10, 20 and 30 g/kg DM of potassium were added as potassium chloride. Results showed that high potassium concentration had no significant effects (P >0.05) on pH, molar concentrations of total or individual volatile fatty acids (VFA), concentrations of C18:0, C18:1 trans 11, C18:1 cis 9, C18:2n-6, or BH of C18:2n-6after incubation. However, concentration and BH of C18:3 n-3were significantly (P <0.01) affected by potassium supplementation. Both the 20 and 30 g/kg DM supplementation significantly (P <0.05 and P <0.01, respectively) decreased the concentration but increased BH of C18:3n-3. This preliminary study indicates that high concentrations ofpotassium alter rumen fatty acid metabolism. Further studies are needed to confirm this and investigate the possible causal mechanisms.}, issn = {1176-5283}, author = {Sun XQ and Dewhurst RJ.Gibbs SJ} } @conference {60936, title = {Effects of sub-clinical endometritis on ovarian follicular activity in postpartum dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {32-36}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {The effects of sub-clinical endometritis (scEndo) on ovarian follicular activity in pasture-fed dairy cows were determined. The uterine-health status of lactating dairy cows (n = 169) was assessed on day (D) 21 ({\textpm} 3 days) postpartum by Metricheck. In a sub-population (n = 47; 32 clean, 15 scEndo), Metricheck assessment was repeated on D42 and uterine cytology undertaken on D21 and D42 [scEndo = polymorphicnuclear (PMN) cells >18\%]. Follicular activity was assessed by ultrasound on D42 and D63. Metricheck evaluation revealed that the proportion of cows with scEndo was 15/169 (8.9\%) and 4/47 (8.5\%) on D21 and D42 respectively. Irrespective of the method used to determine scEndo, dominant (P <0.001) but not subordinate (P >0.1) follicles were larger and grew faster on D63 than on D42. Based on the D21 Metricheck but not the \%PMN classification, dominant follicles of scEndo cows were larger and grew faster (P = 0.02) than those in clean cows. No overall effect of uterine status was found on the subordinate follicles, although these tended (P = 0.06) to be larger on D63 than on D42 but only in clean cows. Thus early postpartum scEndo appears to modulate the subsequent size of the dominant follicle. However, it remains to be determined whether this affects the subsequent fertility of these cows. }, issn = {1176-5283}, author = {Back PJ and Ledgard AM and Beaumont S and Berg MC and Peterson AJ and McNatty KP and Green MP} } @conference {60974, title = {Exploring the relationships between plant chemical composition and nitrogen partitioning in lactating dairy cows fed ryegrass-based diets}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {188-195}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Data from experiments in which cows consumed ryegrass-based diets were used to evaluate the effects of plant constituent concentrations and nutrient ratios on the partitioning of nitrogen (N) secreted into milk and excreted as waste products (urine + faeces). The data set used from 32 publications with 170 treatment means, was derived from studies where freshly-cut or grazed pasture comprised more than 70 \% of the total diet on a dry matter basis. The objectives were to identify suitable predictors of N partitioning, both across and within studies, and to examine the relative weight these predictors have on the partitioning of dietary N. Total excretion of N (g/d) and urinary N (g/d) were best predicted by the single predictor crude protein concentration, but better relationships were obtained by adding water soluble carbohydrate (WSC) and neutral detergent fibre concentrations to the models. Although significant across studies, no single plant constituent variable was selected using the meta-analytical approach. The most reliable predictions of N in waste products and urine required measures of N intake for urinary N excretion, or in combination with total OM intake for total N excretion. }, issn = {1176-5283}, author = {Vibart RE and Koolaard J and Barrett BA and Pacheco D} } @conference {60940, title = {Factors associated with frequency of lameness in dairy cattle managed in pasture based systems with the addition of supplementary feeds : Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {51-53}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Lameness is one of the main welfare problems of New Zealand dairy herds (Chesterton et al., 2008) and contributes directly to cow culling, treatment costs, production losses and reduced economic efficiency (Kossaibati \& Esslemont, 1997). The incidence of lameness can be high, affecting as many as 60\% (Vermunt, 2004) of cows annually, but can vary from between 5 and 55\% (Clarkson et al., 1996) according to differing observation techniques and... Continued}, issn = {1176-5283}, author = {Diaz-Lira CM and Margerison JK and Lopez-Villalobos N and Gibbs SJ} } @conference {60972, title = {Feeding birdsfoot trefoil (Lotus corniculatus) reduces the environmental impacts of dairy farming}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {179-183}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {An indoor feeding experiment using 16 late lactation Friesian dairy cows measured effects of increased proportions of birdsfoot trefoil (Lotus corniculatus; Lotus) in the diet on the partitioning of nitrogen (N) between milk, faeces and urine. Cows were housed in metabolism stalls for 12 days and fed diets containing 0\%, 15\%, 29\% or 45\% Lotus (\% Lotus dry matter (DM) per DM intake (DMI)) with the remainder perennial ryegrass pasture. Increasing the proportion of Lotus in the diet did not affect DMI but increased milk (P <0.001) and milksolids yields (P <0.01). The percentage of N intake partitioned to milk increased from 16\% (0\% Lotus) to 21\% (45\% Lotus) (P <0.01) with an increasing proportion of Lotus in the diet. The percentage of N intake excreted as faecal N also increased from 29\% (0\% Lotus) to 38\% (45\% Lotus) (P <0.001) while the percentage excreted as urinary N was reduced from 49\% (0\% Lotus) to 34\% (45\% Lotus) (P <0.01). Partitioning of N towards faeces has a favourable environmental impact since faecal N is largely retained in soils whereas urinary N is subject to volatilisation as ammonia, losses as nitrous oxides (a greenhouse gas) and leaching into groundwater. }, issn = {1176-5283}, author = {Woodward SL and Waghorn GC and Watkins KA and Bryant MA} } @conference {60978, title = {Genetic and phenotypic parameter estimates for growth, yield and meat quality traits in lamb}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {210-214}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {The Meat and Wool New Zealand Central Progeny Test has evaluated 143 sires from terminal and dual purpose breeds for meat yield and growth. Meat quality traits, including pH, fat and meat colour (CIE L*, CIE a*, CIE b*) have also been measured. This paper determines genetic variation in these quality traits and their correlations with growth and meat yield. Progeny were drafted for slaughter at a threshold live weight of 34 kg at weaning and 36 kg for subsequent slaughters. Fat colour, eye muscle meat colour and meat pH were measured 24 hours post-slaughter, with meat colour measured after a 30 minute bloom. Heritabilities and genetic correlations between traits were calculated from the measurements. Data were analysed with a linear mixed model in ASReml. Results showed significant variation among sires for meat quality. Heritabilities were moderate for most meat quality traits: fat colour (CIE b* 0.42), initial meat colour (CIE L* 0.29, CIE a* 0.19) and pH (0.12). Relationships between meat quality and yield/growth showed that meat CIE L* had a positive genetic correlation with weaning weight (0.42). Simulated index selection for growth rate and meat yield predicted a small increase in meat lightness and decline in fat yellowness (0.231 and -0.227 units per generation and unit selection intensity, respectively). }, issn = {1176-5283}, author = {Payne GM and Campbell AW and Jopson NB and McEwan JC and Logan CM and Muir PD} } @conference {60980, title = {Genetic parameters for colour stability of chilled lamb : Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {220-222}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {An increasing proportion of New Zealand lamb meat is shipped to the European Union market as chilled rather than frozen product, with 29\% exported as chilled product in 2005/06 (Meat and Wool New Zealand, 2006). New Zealand{\textquoteright}s lamb export markets are located such that the chilled product travels large geographical distances via freighted shipping, taking six to twelve weeks to reach the destination. Once chilled lambs arrives at its destination it is further processed and packaged to specification for retail sale. Shelf life and colour stability are particularly important for this... Continued }, issn = {1176-5283}, author = {McLean NJ and PL Johnson and Bain WE and Greer GJ and Dodds KG} } @conference {60979, title = {Genetic parameters for primal cut meat yield traits in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {215-219}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Lamb carcass grading is changing from classification on carcass weight and tissue depth (GR) to yield grading systems such as VIAscan{\textregistered}. Under the VIAscan{\textregistered} system, farmers receive information on the percentage lean meat yield from the hindleg, loin and shoulder primal cuts, and payments are based on these measurements. Genetic improvement programmes for meat have concentrated on producing age-adjusted breeding values for carcass lean and fat weight from live weight and ultrasonic eye muscle measurements. This has worked well for grading using carcass weight and GR, but does not quantify differences in yield between meat cuts. Carcass and VIAscan{\textregistered} yield data collected for the Meat and Wool New Zealand Central Progeny Test were analysed to determine heritabilities and genetic and phenotypic correlations for meat yield traits. The dataset contained around 6,600 progeny from 143 terminal sire or dual purpose rams. Data were analysed using linear mixed models in ASReml. The results showed significant variation between sires for lean yield traits. Heritabilities for age-adjusted lean weight in the hindleg, loin and shoulder were 0.40, 0.37 and 0.42, respectively. Genetic correlations for age-adjusted weight of lean by carcass region were all high (range 0.94 to 0.96), but were lower (0.62 to 0.85) when adjusted to constant carcass weight. }, issn = {1176-5283}, author = {Jopson NB and McEwan JC and Logan CM and Muir PD} } @conference {60977, title = {Genetic parameters for somatic cell score in dairy goats estimated by random regression}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {206-209}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {The objective of the study was to estimate genetic parameters of somatic cell score (SCS = log2 of somatic cell count / 1000) in New Zealand mixed-breed dairy goats using a random regression model. The dataset comprised 37,051 herd-test records of somatic cell counts (SCC) from 3,688 does kidding between 2000 and 2007 distributed in 47 herds. The mixed model included the fixed effects of contemporary group (herd-year-month of kidding), lactation number (1st, 2nd and 3rd), and the covariables day-of-month, proportion of Saanen, Nubian, Alpine and Toggenburg breeds, heterosis, and a second-order orthogonal polynomial of days in milk across all data and for each lactation number. The random effects included a second order random regression polynomial for the additive animal effect and the doe permanent environmental effect within parity and doe permanent environmental effect across parities. The residual variance was assumed heterogeneous, with different residual variances for each of the nine months of lactation. Estimates of heritability increased from 0.12 to 0.25 from the beginning to the end of the lactation and estimates of repeatability ranged from 0.46 to 0.59, also increasing from the beginning to the end of lactation. These results show that genetic improvement can be achieved in SCC by including SCS in selection index. }, issn = {1176-5283}, author = {Apodaca-Sarabia CA and Lopez-Villalobos N and Blair HT and Prosser CG} } @conference {60941, title = {Identification of potential impacts of New Zealand dairy housing systems on dairy cow welfare : Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {54-56}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Although housing of dairy cows is not acommon management practice in New Zealand, it is becoming increasingly used for a variety of reasons. Potential benefits from dairy housing have been identified as pasture protection, effluent management, cow health and welfare, supplementary feed management and increased production (Dexcel, 2005). Laven and Holmes (2008) further explored potential health and welfare issues associated with increased use of housing for dairy cows in New Zealand. However, there is to date very little empirical research... Continued}, issn = {1176-5283}, author = {Arnold NA and Verkerk GA and Gregory R and Matthews LR} } @conference {60953, title = {Investigating marbling and its relationship to meat quality in New Zealand pasture fed lamb}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {104-107}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {This is the first report of marbling in New Zealand pasture finished lamb. Marbling and meat quality data were collected on 1,056 loins from pasture finished lambs. Marbling was subjectively assessed on loin cut surfaces, using a five point visual scale (1 = Low, 5 = High), and objectively assessed using computer tomography (CT) scanning. Tenderness was objectively measured on loins that had been frozen. Corresponding loins from the lambs with the fifty highest (High) and fifty lowest (Low) subjective marbling scores were taste panelled after chilled storage. The average subjective scores were 2.94 and 0.94 for the High and Low groups respectively, with the objectively measured CT fat percentages 8.0\% and 10.0\% respectively, both significant differences (P <0.001). Loins from the High group were significantly (P <0.01) more tender than loins from the Low group as assessed objectively, however, this difference was not detected by the taste panel when assessing texture. The taste panel did not detect any significant differences in juiciness, flavour or odour between the two groups. Our findings suggest that this level of marbling in pasture fed, New Zealand chilled stored lamb is insufficient to influence meat quality as assessed by a taste panel. }, issn = {1176-5283}, author = {Young EA and Bain WE and McLean NJ and Campbell AW and PL Johnson} } @conference {60962, title = {Lancorp Farming Lecture: {\textquoteright}Clean, green and ethical{\textquoteright} animal reproduction: extension to sheep and dairy systems in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {140-147}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {In this paper, we present our approach for {\textquoteright}clean, green and ethical{\textquoteright} (CGE) management in small ruminants and dairy cattle, in a context that is relevant to New Zealand livestock industries. We will focus in particular on reproduction and nutrition aspects, with several possibilities for CGE management: 1) control of the timing of reproductive events by using socio-sexual signals (the {\textquoteright}male effect{\textquoteright}) to induce synchronised ovulation in females; 2) {\textquoteright}focus feeding{\textquoteright} - short periods of nutritional supplementation that are precisely timed and specifically designed for each event in the reproductive process; 3) {\textquoteright}nutritional pharmacology{\textquoteright} - a term that reflects the possibility of using forages containing {\textquoteright}bioactive{\textquoteright} compounds to improve rumen health and efficiency with environmental benefits through the reduction of methane emissions from ruminants; 4) maximizing offspring survival by a combination of management and nutrition; 5) genetic selection for fertility, fecundity and temperament. These tools involve novel ways of manipulating the endogenous control systems and production of animals. Ultimately, the CGE tools can be cost-effective, increase productivity and, at the same time, greatly improve the image of meat and milk industries in society and the marketplace. }, issn = {1176-5283}, author = {Martin GB and Durmic Z and Kenyon PR and Vercoe PE} } @conference {60930, title = {Management of weanlings on commercial Thoroughbred stud farms in the North Island of New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {4-9}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {The feeding of concentrates to growing thoroughbred horses in New Zealand is common practice, despite the availability of pasture all year round. Whilst the sale of young stock is the primary focus of the majority of the breeders in the Thoroughbred industry, there is still limited data on the production process and the optimal strategy to grow horses to their maximum athletic potential. To obtain data on the management of Thoroughbred weanlings a face-to-face survey was conducted on 46 stud farms in the northern and central regions of the North Island during the 2007/08 breeding season. Analysis was based on location and size of the breeding operation. Prior to weaning, 87\% of foals were exposed to concentrate feed and all weanlings received concentrates. Weanlings received 47 {\textpm} 2 MJ of digestible energy (DE) and 563 {\textpm} 40 g of crude protein (CP) per day from concentrate initially. This increased to 64 {\textpm} 6 MJ DE and 683 {\textpm} 54 g CP immediately before yearling preparation. The data collected indicated that management of weanlings is generally consistent between regions and across farm sizes with weanlings receiving large quantities of concentrate feed whilst at pasture. }, issn = {1176-5283}, author = {Stowers NL and Rogers CW and Hoskin SO} } @conference {60931, title = {Maternal environment as a regulator of birth weight and body dimensions of newborn lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {10-14}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {The present research study was undertaken to investigate the effect of maternal uterine environment on birth weight of lambs. Embryos were transferred within, and reciprocally between, Suffolk and Cheviot sheep to establish four groups of pregnancies: Suffolk in Suffolk (SinS; Large control), Suffolk in Cheviot (SinC; Restricted uterine environment) Cheviot in Suffolk (CinS; Luxurious uterine environment) and Cheviot in Cheviot (CinC; Small control). Birth weight and other morphological characteristics of lambs such as head width, head length, crown-rump length, heart girth, fore leg length, hind leg length and femur length were recorded within 24 h of birth. Various placental parameters were also recorded at lambing. Birth weight of SinC lambs (5.04 {\textpm} 0.20 kg) was significantly (P <0.05) lower than SinS lambs (5.93 {\textpm} 0.19 kg). All of the body dimensions were also significantly (P <0.05) reduced in SinC compared with SinS lambs. However, neither birth weight nor other morphological parameters were significantly different (P >0.05) between CinC and CinS lambs. Among placental parameters, cotyledon number was significantly (P <0.05) lower in CinS (57.48 {\textpm} 6.27) than SinS group (74.17 {\textpm} 5.88). These results indicate that a restricted maternal uterine environment affects birth weight probably via alteration to placental characteristics. }, issn = {1176-5283}, author = {Sharma RK and Jenkinson CMC and Blair HT and Kenyon PR and Parkinson TJ} } @conference {60951, title = {A new generation meat program in Australia within the Co-operative Research Centre for Sheep Industry Innovation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {96-100}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {The Information Nucleus flock (INF) is the central focus of the Co-operative Research Centre (CRC) for Sheep Industry Innovation. It is made up of eight sheep flocks across Australia that are genetically linked by the use of common sires. The objective of the INF is to measure a range of biological and production parameters and to produce heritability estimates and genetic correlations for a range of new traits. Approximately 100 sires are mated annually by artificial insemination to 5,000 ewes across the sites. Sires from various breeds are joined to Merino and crossbred ewes. Each year 2,000 progeny are evaluated for a wide range of meat production and consumer-relevant traits. Some of these traits are new and novel, such as the content of iron, zinc and omega-3 fatty acids. Their measurement is designed to ensure lamb maintains its marketing edge as a healthy, nutritious meat so that it is the consumer{\textquoteright}s preferred choice of meat. This paper will provide an overview of the program and highlight specific areas that are novel with respect to sheep meat. }, issn = {1176-5283}, author = {Pethick DW and Jacob RH and McDonagh MB and O{\textquoteright}Halloran WJ and Ball AJ and Hopkins DL} } @conference {60946, title = {An option for managing triplet bearing ewes on extensive properties}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {71-74}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Heavier ewe live weights and the trend toward composite genetics has resulted in an increasing proportion of triplet bearing ewes within a flock. On some extensive properties, triplet lambs have much lower survival rates. This work examined the effect on lamb survival and the profitability of shifting scanned triplet ewes to an intensive property for lambing. Scanned triplet bearing ewes on a large extensive property were allocated to two groups; Intensive (150 ewes) and Extensive (770 ewes). Intensive ewes were transported to a smaller downland property prior to lambing and the Extensive ewes remained on the farm and were managed normally. Weaning percentages were higher under intensive management (222\% lambs weaned/ewe present at weaning) than under extensive management (171\%). The intensive property also had higher lamb weaning weights per ewe (58.2 vs 47.2 kg lamb weaned/ewe scanned). Differences in survival between the properties suggest there is a significant potential to reduce death rate in triplet lambs. Returns on feed consumed were modelled using Farmax{\textregistered} and were 21.1 and 17.1 c/kg dry matter consumed over the trial period on the respective properties. In addition, removal of the triplet bearing ewes from the extensive property freed up resources which could be used to improve the performance of other stock. }, issn = {1176-5283}, author = {Thomson BC and Muir PD} } @conference {69018, title = {Parasite-related traits in lambs sired by resistant or resilient Romney sires : Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {228-229}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Finding methods of dealing with increasing levels of anthelmintic resistance is important to the New Zealand sheep industry. Genetic selection within the sheep population for animals that are less reliant on anthelmintic therapy is one approach, and AgResearch has bred selected lines of Romneys over recent decades. These have included lines for resistance and for resilience (Bisset et al., 2001). The resistant line, selected for low faecal egg count (FEC) in lambs, was established in 1979. The line selected for increased resilience in lambs was set up in 1994. Resilience is the ability of animals to maintain acceptable health and growth under high parasite challenge, with minimal need for anthelmintic treatment. We report results here from a study to evaluate sires from these two long-term breeding lines, with progeny measured for weaning weight (WWT) and faecal egg count (FEC) at weaning.}, issn = {1176-5283}, author = {Wheeler M and Morris CA and Devantier BP} } @conference {60929, title = {Presidential Address 2008: Where are we going and who{\textquoteright}s driving?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {1-3}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {I come to the 2008 Presidential Address in the unusual, but not unique, situation of preparing to leave New Zealand and move to a new research leadership position overseas. I hope that this will give me an even better platform from which to make some constructive and objective comments about the direction of our research and livestock industries. I will take the approach recommended by a previous research director of... continued }, issn = {1176-5283}, author = {Dewhurst RJ} } @conference {60937, title = {Prevalence and identification of systemic markers of sub-clinical endometritis in postpartum dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {37-42}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {The prevalence of sub-clinical endometritis (scEndo) and identification of serum markers of scEndo was investigated in pasture-fed, postpartum dairy cows. Mixed age lactating dairy cows (n = 169) were examined for uterine health status on day (D) 21 postpartum ({\textpm} 3 days) by Metricheck classification. On D42 in a subpopulation (n = 47; 32 clean, 15 scEndo) Metricheck assessment was repeated and uterine cytology undertaken on D21 and D42 [scEndo = polymorphicnuclear (PMN) cells >18\%]. Uterine bacteriology, as well as haematological, biochemical and milk parameters were also measured. The prevalence of scEndo was 15/169 (8.9\%) and 4/47 (8.5\%) cows on D21 and D42 respectively. A high incidence of self-resolving scEndo (11/15, 73\%) was revealed. Numerous species of pathogenic bacteria were isolated from both scEndo and clean cows. Despite the uterine infection being sub-clinical, systemic markers were detectable as on D21 and D42 haematological and biochemical parameters differed. Irrespective of the scEndo classification method used, the mean blood neutrophil concentration was higher (P <0.05) and plasma albumin lower (<0.05) in scEndo cows compared to clean cows. Milk fat and protein \% also differed (P <0.05) between scEndo and clean cows. The monitoring in early lactation of these markers could aid identification of scEndo, thereby preventing potentially detrimental effects on subsequent fertility. }, issn = {1176-5283}, author = {Green MP and Ledgard AM and Berg MC and Peterson AJ and Back PJ} } @conference {60954, title = {Quality of chilled-never-frozen versus chilled-frozen-thawed lamb : Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {108-111}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Chilled lamb currently attracts a premium price over frozen accelerated conditioning and ageing (AC\&A) lamb in New Zealand{\textquoteright}s traditional lamb markets. AC\&A lamb is fully frozen within 48 h of slaughter (Hagyard, 1979). The price differential between chilled-never-frozen (CNF) and AC\&A frozen lamb is due to CNF lamb having more reliable tenderness, less drip loss and longer colour display life than AC\&A lamb. There is no clear evidence that the eating quality of CNF lamb is superior to... Continued }, issn = {1176-5283}, author = {Wiklund E and Farouk MM and Stuart A and Cartwright S and Penney N and Rosenvold K} } @conference {60966, title = {Rates of genetic progress being achieved throughout the New Zealand ram breeding industry}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {155-157}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Changes in the rate of genetic progress in the New Zealand sheep industry since 1990 are linked to structural aspects of breeding scheme design and to major industry sheep breeding initiatives. Data was sourced from the December 2007 SIL-ACE genetic evaluation for 140 recorded Dual Purpose flocks and 62 recorded Terminal Sire flocks. Genetic trends in both of these flock types approximately doubled after the introduction of Sheep Improvement Ltd. and there was a further incremental increase of similar magnitude after the introduction of the Central Progeny Test and SIL ACE. Substantial variation in the magnitude of genetic trends was observed across flocks within and between breeds. Large numbers of flocks average less than 50 cents gain in index per year, while significant numbers of flocks are achieving in excess of 150 cents gain per year. Flocks with higher rates of genetic gain tended to be using superior rams introduced from other flocks, while flocks with lower rates of genetic gain tended to be repeatedly using older sires of lower genetic merit. The implications of these results for industry sheep genetic improvement initiatives are discussed. }, issn = {1176-5283}, author = {Amer PR} } @conference {60973, title = {Real time in situ measurement of rumen methane concentration in the rumen of cattle : Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {184-187}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Methane dominates agricultural greenhouse gas emissions in New Zealand (Leslie et al., 2008). Research efforts in New Zealand to date have been directed toward prediction of emissions, most often using the rumen gas marker sulphur hexafluoride (SF6) (Lassey et al., 1997) to predict methane emissions in grazing livestock. However, the errors associated with this method necessitate the use of multiple day sampling programmes and large numbers of individuals to overcome... Continued }, issn = {1176-5283}, author = {Laporte-Uribe J and Gibbs SJ} } @conference {60949, title = {Realities of clip preparation for strong wool from adult sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {85-89}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {There has been debate about the usefulness and profitability of varying standards of clip preparation, and the timing and frequency of shearing. This paper takes a modelling approach to gauge the relative economic value of adjusting these factors to modify the style of wool. Although adult fleeces were used as the basis for the analyses presented, the model can be used to handle all types of wool. The model shows that shearing in spring, when wool colour is best, increases wool revenue. There may however, be conflict with the overall management of the ewe flock. Similarly, shearing twice a year will yield higher wool revenue, but provides a lower net margin from wool because of higher shearing costs, but with possible management benefits. Skirting levels can have a greater impact on wool revenue of twice-yearly shorn fleece wool as second shorn oddments are primarily downgraded on length with little change in yellowness. If the grower is supplying to a specified contract, the price differential associated with clip preparation may be substantively greater than those apparent in the auction. }, issn = {1176-5283}, author = {McDermott AK and Sumner RMW} } @conference {60957, title = {Relationship between blood phylloerythrin concentration and gamma-glutamyltransferase activity in facial eczema-affected cattle and sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {118-122}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Phylloerythrin (PLE) is a photo-dynamic compound, a natural breakdown product of chlorophyll. Its concentration and relationship with gamma-glutamyltransferase (GGT) were determined in animals seriously affected with facial eczema (FE). Seven commercial cattle herds (n = 1,455) and one experimental sheep flock (n = 597), each containing clinically affected animals, were monitored. On a pooled within-farm basis, mean PLE concentration was significantly higher in clinical FE cases than in non-clinical animals in cattle (28.7 vs 16.0 relative units, P <0.001), and in lambs (0.282 vs 0.024 {\textmu}g/ml, respectively, P <0.001). PLE concentration rose in some, but not all, animals when GGT activity exceeded \~{}600 IU/L in cattle and \~{}400 IU/L in lambs (Reference GGT range in normal (unchallenged) animals: 0 to 40 IU/L, cattle; 32 to 70 IU/L, sheep). A heritability for PLE concentration was estimated in cattle (0.19 {\textpm} 0.07), and phenotypic and genetic correlations with LogeGGT were 0.37 {\textpm} 0.02 and 0.92 {\textpm} 0.09, respectively. In the lambs the phenotypic correlation between LogeGGT and PLE was 0.32 {\textpm} 0.04. Thus PLE is a partially inherited trait, and is associated with visible signs of FE, especially above GGT thresholds of \~{}600 IU/L in cattle and \~{}400 IU/L in lambs. }, issn = {1176-5283}, author = {Morris CA and Hickey SM and Phua SH} } @conference {60976, title = {Responses to selection for pubertal traits in Angus cattle over 23 years}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {201-205}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Selection to change age at puberty over 23 years was monitored in Angus cattle in a Ruakura study. A foundation herd was divided in 1984 into four lines: a control unselected line, and lines selected for high age-at-puberty (Age+), low age-at-puberty (Age-), and high scrotal circumference (SC), with the last two lines being merged later. Age at puberty (first oestrus, AFO) was determined in heifers from observations of first behavioural oestrus date; puberty was determined in bulls from SC records from 8 to 13 months of age. Selection for AFO was applied mainly to bulls, using the genetic correlation between AFO and SC from our data (-0.25 {\textpm} 0.09). Puberty records from 6,473 weaned calves were analysed, using restricted maximum likelihood methods to determine genetic changes achieved by line. Realised heritability estimates were 0.26 {\textpm} 0.03 (standardised AFO), and 0.40 {\textpm} 0.04 (individual SC records; repeatability over ages, 0.68 {\textpm} 0.01). Averaging over recent year{\textquoteright}s data, Age- line heifers had lower AFO than Age+ line heifers by 69 days (19\%; 1.33 phenotypic standard deviations), and bulls had larger SC by 3.0 cm (9.9\%; 1.17 phenotypic standard deviations). Correlated responses in pregnancy rate favoured Age- over Age+ females at all ages. }, issn = {1176-5283}, author = {Amyes NC and Morris CA} } @conference {60959, title = {Retrospective examination of the breeding efficiency of the New Zealand Thoroughbred and Standardbred}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {126-131}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {To describe the industry structure and breeding efficiency of the Thoroughbred and Standardbred populations in New Zealand retrospective reproductive data for the 1989/90 to 2004/05 breeding seasons were obtained from online industry databases and collated for analysis. Data were examined using descriptive statistics, and Kaplan-Meier survival analysis. From 1989/90 to 2004/05 breeding season there was a 36\% and 37\% reduction in the national broodmare herd and 45\% and 40\% reduction in foal crop for the Standardbred and Thoroughbred populations, respectively. During this period the number of sires decreased but there was an associated increase in the mean number of mares served by a sire. The mean end of season fertility was 77.9 {\textpm} 0.3 \% for Thoroughbreds and 86 {\textpm} 0.2 \% for Standardbreds. The commercial life of a stallion was estimated to be 3 and 4 years for Thoroughbred and Standardbred sires, respectively. Shuttle sires were younger, and covered larger books of younger mares than other sire categories. Expensive and shuttle sires cover larger books of younger mares and therefore may have an advantage compared to low or medium priced sires in producing larger numbers of potentially successful progeny.}, issn = {1176-5283}, author = {Rogers CW and Gee EK and Vermeij E} } @conference {60958, title = {Seasonal variation in venison drip loss and tenderness : Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {123-125}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Venison is a high quality product with several attributes attractive to consumers. It is tender, has low fat content, has a favourable fat composition and has high levels of minerals (Hoffman \& Wiklund, 2006). However, New Zealand venison processors have indicated a seasonal variation in the amount of drip. Poor colour stability can also be a problem, sometimes even in vacuum bags when it can occur after extended storage of chilled product. The purpose of this study was to determine seasonal variation in drip loss and tenderness in... Continued }, issn = {1176-5283}, author = {Wiklund E and Stuart A and Dobbie PM and Littlejohn RP} } @conference {60963, title = {Sheep Improvement Limited (SIL) - the first 10 years: Introductory remarks}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {148}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Garrick et al. (1992) defined the six major components of performance recording schemes designed for genetic improvement on a national scale as committed buyers, motivated breeders, database, genetic technology, animal breeding research, and extension. The major factor determining the effectiveness of a national scheme is the way that each of these components is matched to industry needs and... Continued }, issn = {1176-5283}, author = {Newman S-AN} } @conference {60964, title = {SIL - progress over a decade}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {148-152}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {In the 10 years that Sheep Improvement Ltd (SIL) has been operational, the system has continued to develop to meet the needs of breeding flock owners and their ram buying clients. New traits have been added to the evaluation. More flocks are using across-flock evaluations, but there is the opportunity to grow this significantly. The language of SIL is well accepted by industry and offers the most likely path to integration of DNA based genetics into the sheep industry. While a large proportion of rams used by the New Zealand sheep industry come from SIL flocks, a significant section of the industry are still not comfortable with SIL figures when purchasing rams. Greater penetration into the ram buying industry and further into the meat processing industry are challenges for SIL and its collaborators. SIL must maintain and enhance its relevance to industry. This means focused research that addresses key issues and a significant extension effort to increase the proportion of industry that has confidence in using SIL and related technologies. }, issn = {1176-5283}, author = {Young MJ and Wakelin R} } @conference {60965, title = {SIL-ACE - Increasing access to genetic information for sheep farmers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {153-154}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {SIL-ACE is a large-scale, across-flock, across-breed genetic evaluation carried out bi-monthly by SIL. Goal trait groups considered include Growth, Meat (carcass merit), Wool, Reproduction and Resistance to internal parasites. The SIL-ACE dataset comprises over 330 flocks and 3.2 million animals. Leader lists for top-rated 200 sires are published on the www.sil.co.nz website. These comprise the top 5 to 10\% of sires for each index or goal trait group considered. Visual depictions of flock connectedness are also provided. Breeders obtaining within flock reports based on the SIL-ACE genetic evaluation, can use a percentile bands table as a scale to judge the merit of animals they are considering for selection. Developments underway will lead to other traits being added to the SIL-ACE evaluation such as lamb survival and ewe performance, resulting in more powerful selection tools to better target genetics suited to a particular users needs. }, issn = {1176-5283}, author = {Young MJ and Newman S-AN} } @conference {60981, title = {A simulation model to partition ewe efficiency into component traits for genetic analysis}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {223-227}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Ewe efficiency is extremely topical in the New Zealand sheep industry. This paper describes a stochastic simulation model which facilitates partitioning of a defined ewe efficiency equation into its component genetic traits. It accounts for, and simplifies, the complex and sometimes unfavorable interactions among components of ewe efficiency. The model tracks simulated genetic effects, inherited from the ewe{\textquoteright}s sires, in breeding ewes and their lambs for key performance recorded traits. The traits simulated are weaning weight, mature weight, number of lambs born, lamb survival, and longevity. Ewe efficiency is defined as the difference between value of lambs weaned and ewe and lamb costs, rather than as a ratio. Output value in NZ$ for the efficiency equation is computed on a ewe by ewe basis, as a function of number of lambs born, lamb survival and weight of lamb weaned, with each of these components partly influenced by one or more genetic effects inherited from simulated sires of the breeding ewes. Preliminary results from the model have identified litter size, ewe longevity, maternal lamb survival, and maternal weaning weight as being important drivers of ewe efficiency. The relative balance of their importance is influenced by farm production levels and environment. }, issn = {1176-5283}, author = {Sise JA and Shackell GH and Byrne TJ and Glennie SF and Amer PR} } @conference {60932, title = {Strategically reducing time on pasture: Dairy cow intake, production, welfare, and excretory behaviour}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {15-19}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {In wet spring conditions, cows are often stood off pasture reducing their pasture intake. However, studies indicate that despite reduced grazing access, pasture intake and milk production can be maintained. This study restricted daily grazing access to eight hours in early lactation to determine the effect on pasture intake, milk production, and urination distribution. Forty-eight Holstein-Friesian cows were allocated to three duplicated treatments. Cows had access to pasture for either four hours after each milking (2x4), eight hours between milkings (1x8), or for 24 hours, excluding milking times (Control). When not grazing, the 2x4 and 1x8 treatments were stood off on a bark pad. The 1x8 cows ate less pasture (10.9 kgDM/cow/d; P <0.05) than the Control (13.6 kgDM/cow/d), but the 2x4 intake (13.0 kgDM/cow/d; P = 0.46) was not different to the Control. The 1x8 and 2x4 cows produced less milk (20.2 and 21.5 kg milk/cow/d respectively; P <0.05), relative to the Control (23.3 kg milk/cow/d). Urinations on pasture and races were reduced (P <0.05) from 90\% (Control) to 62\% (1x8) and 65\% (2x4) of total urinations. Eight-hours grazing per day should be offered as two four-hour periods to maintain cow pasture intakes, although milk yields are reduced. Corresponding changes in urination distribution may have environmental benefits. }, issn = {1176-5283}, author = {McLeod KLM and Clark CEF and Glassey CB and Gregorini P and Costall DA and Betteridge K and Jago JG} } @conference {60967, title = {Trans-Tasman genetic evaluation of sheep - spreading the net wider}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {158-160}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {At the instigation of local breed groups, Sheep Improvement Ltd. (SIL) and Sheep Genetics (SG) exchanged flock data and conducted genetic evaluations on the combined dataset. Results from each system show only modest changes in breeding values compared to analyses of their respective within country datasets. Correlations of breeding values (BVs) were 96 to 100\% for weaning weight, autumn live weight, ultrasonic muscle, ultrasonic fat, fleece weight and number of lambs born. Correlations between BVs generated by the two systems from the same datasets were less strong but still good at 69 to 89\%, for most traits. This was attributed to differences in parameters used by the two analysis systems and to some measurements being taken at different ages. The weakest correlations occurred for ultrasound scan traits at 14 to 65\% since SG adjusts these to constant {\textquoteright}carcass{\textquoteright} weight but SIL does not. It is concluded that the best option for breeders seeking superior genetics internationally is to facilitate data exchange and have analysis and reporting done within their own country. }, issn = {1176-5283}, author = {Young MJ and Newman S-AN and Apps R and Brown DJ} } @conference {60944, title = {Understanding the interaction of prolactin and leukaemia inhibitory factor signalling during the switch from lactation to involution : Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {65-67}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {The molecular mechanisms involved in involution of the bovine udder, a process which underpins lactation persistency, are poorly understood. During rodent lactation, STAT5 is activated in response to prolactin (PRL) to stimulate milk protein production (Liu et al., 1997). At the onset of involution, STAT5 is rapidly inactivated (Schmitt-Ney et al., 1992), and STAT3 is activated by leukaemia inhibitory factor (LIF) to... Continued}, issn = {1176-5283}, author = {Singh K and Vetharaniam I and Prewitz M and Dobson J and Stelwagen K} } @conference {60975, title = {Urinary nitrogen excretion from cows at different stage of lactation grazing different ryegrass cultivars during spring or autumn}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {196-200}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {The effects of season (spring or autumn) and stage of lactation (early or late) on the partitioning of dietary nitrogen (N) between milk and urine were measured in experiments in which cows grazed forages with putative differences in the ratio of water soluble carbohydrates (WSC) to crude protein (CP). Sixty cows (n = 30 for each stage of lactation) grazed one of three forages during spring and autumn. Forage treatments consisted of a {\textquoteright}standard{\textquoteright} perennial ryegrass (STG) and two ryegrasses with high WSC concentrations: a perennial {\textquoteright}high sugar{\textquoteright} ryegrass (HSG), and an annual ryegrass (IRG). In spring, grass type had a significant effect on the estimated urinary N excretion. Both the HSG and STG resulted in greater N excretion compared to the IRG, due to the low CP concentration in this forage in one of the grazing periods. In autumn, cows grazing STG excreted less urinary N than both HSG and IRG. In both seasons, cows in early lactation secreted more N into milk but were not different in N excretion. In early lactation cows, the extra N in milk was only a small proportion of the potential N intake arising from higher CP content in autumn grasses. }, issn = {1176-5283}, author = {Pacheco D and Lowe K and Burke JL and Cosgrove GP} } @conference {60935, title = {Using an existing intake model to demonstrate relationships between herbage allowance, hunger drive, days in milk and actual intake in grazing dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {28-31}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {A sheep intake model was adjusted for dairy cows and used to illustrate intake in relation to inherent hunger, days in milk (DIM), and herbage allowance. Intake is predicted by an exponential function of pregrazing herbage mass, stocking density and hunger drive (k). In adjusting the model, k was re-parameterised using a data set of n = 1,198; it was then adjusted to represent intake decline from peak to end of lactation. This adjustment resulted in splitting k into a and b. Parameter a represented inherent hunger and b its persistence during lactation. The re-parameterised model was tested against an independent data set (n = 287). The square root of mean prediction error was 1.57, indicating good prediction accuracy. Data from three different cow strains, New Zealand-70 and -90 and North American-90 (n = 210, 293 and 271, respectively) were used to reestimate a and b, and to illustrate inherent hunger drive. a and b differed (P <0.01) between strains. Then, with the adjusted and re-parameterized models, the interaction effect of herbage allowance, strain, and DIM on intake were simulated. The adjusted model offers an easy-to-use tool to compare, interpret and illustrate feeding scenarios. }, issn = {1176-5283}, author = {Gregorini P and Romera AJ and Beukes PC and Rossi JL and MacDonald KA} } @conference {60971, title = {The variation in methane emissions from sheep and cattle is not explained by the chemical composition of ryegrass}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {174-178}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {A data base of over 3,000 ruminant methane emission records from individual animals used to compile New Zealand{\textquoteright}s greenhouse gas inventory, shows substantial variation in CH4 yields (g/kg dry matter intake (DMI)) within and between forage types. Multiple regression analyses were undertaken using datasets from sheep and cattle fed fresh ryegrass to determine the extent to which variation in CH4 yields could be explained by ryegrass chemical composition. Methane was measured using the SF6 marker dilution technique with sheep and cattle, and also directly by respiration calorimetry from sheep. Data from sheep showed a similar average CH4 yield from both techniques, but there was more variation in SF6 data (23.4 {\textpm} 5.73) than from calorimetry (23.1 {\textpm} 2.89). Cattle CH4 yields averaged 19.1 {\textpm} 3.70 g/kg DMI. Multiple regression analysis of sheep data showed pasture chemical composition accounted for <2\% of the variation determined by SF6 and 20\% of the variation from calorimetry. Only 13\% of the variation in yield from cattle was explained by ryegrass composition, so the majority of variance (>80\%) was not explained. We suggest the variation in CH4 emissions is affected by digestive characteristics of individual animals, and interactions with forage physical and chemical components. }, issn = {1176-5283}, author = {Hammond KJ and Muetzel S and Waghorn GC and Pinares-Patino CS and Burke JL and Hoskin SO} } @conference {60950, title = {Variation of wool between and across the fleeces of composite-breed strong wool sheep in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {90-95}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Many farmers in New Zealand have moved towards using composite-breed sheep flocks to increase the meat production and fecundity of their stock. We aimed to determine whether flocks with a wider genetic base had greater between and within-fleece variation than single-breed flocks. Wool from seventeen body sites of sheep from five flocks of diverse genetic background (Romney, Coopworth, and crosses with Texel, Finnish Landrace and East Friesian breed lines) were compared. Both mean fibre diameter and mean fibre curvature differed between flocks (P <0.001), and across the body (P <0.01). While fibre diameter was more consistent, fibre curvature was more variable across the finer fleeces of flocks with some Finnish Landrace influence. Wool was shorter in Texel crosses, resulting in more consistent length across body sites. Our data suggests that composite-breed sheep exhibit increased within-fleece variation of some wool traits and decreased variation of others. Of most significance was that the extent of wool variation across body sites varied considerably between sheep, regardless of their genotype. In general, there was little association between wool traits with respect to this across-fleece uniformity. Fleece uniformity can be assessed by sampling across the anterior-posterior axis. Selection of stock with more uniform fleeces for specific traits may aid the production of wool better specified to satisfy differentiated niche markets. }, issn = {1176-5283}, author = {Craven AJ and Ashby MG and Wildermoth JE and Cox NR and Scobie DR and Nixon AJ} } @conference {41804, title = {Are serum amyloid protein levels in milk an indicator of mastitis infection in New Zealand dairy goats ?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {105-106}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {The incidence of clinical mastitis in dairy goats is low at less than 5\% per lactation (Bergonier et al., 2003), however, there is a recognised need in the industry for a simple, practical and reliable means for the detection of sub-clinical mastitis. In goats, conversely to cows, somatic cell counts (SCC) are not a reliable indicator of infection. Bacteriological cultures can be used to identify glands with subclinical infection, but this approach involves specialized sampling. Serum amyloid A (SAA) is a family of acute phase proteins that is produced in response to infection and inflammation. Levels of this protein in milk have been ...Continued }, issn = {1176-5283}, author = {Hodgkinson AJ and Kivits LJ and Molenaar AJ and McDougall S and Prosser CG} } @conference {42027, title = {Artificial insemination of red deer (Cervus elaphus) hinds late in the breeding season}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {12-15}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {Red deer hinds in New Zealand typically conceive around April, however they have spontaneous ovulatory activity extending until September. There is little experience with mating late in the potential breeding season and there is some evidence that they may not be able to achieve pregnancy at this time of the year. The present study determined whether red deer hinds are capable of becoming pregnant following an induced ovulation in August. Ten adult red deer hinds were treated with intravaginal progesterone-releasing devices (CIDRs) and equine chorionic gonadotrophin during May prior to set time artificial insemination or were untreated, non inseminated controls. Ovulation and pregnancy were monitored by measurement of plasma progesterone concentration and rectal ultrasonography, respectively. This procedure was repeated in August. The progesterone data showed that the control hinds experienced spontaneous ovulations on both occasions and that, following CIDR removal, 9/10 and 10/10 treated animals ovulated in May and August respectively. Pregnancy rate at 45 days post insemination was 5/9 and 3/10 animals ovulating in May and August, respectively. Although these results showed modest success of set time artificial insemination following induced ovulation, they clearly indicated that red deer hinds are capable of conceiving successfully late in the breeding season. }, issn = {1176-5283}, author = {Quinn-Walsh EC and Wellby M and Ridgway MJ and Barrell GK} } @conference {42048, title = {Artificial insemination success rates for Meat and Wool New Zealand central progeny test sires}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {77-78}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {National progeny testing schemes have become important components of national sheep genetic improvement programmes in Australia, France, and New Zealand (Fogarty et al., 2002; Bib{\'e} et al., 2002; Campbell et al., 2005). In 2001 the Alliance Central Progeny Test was established, this was combined in 2005 with the Elite Lamb Progeny Test to become the Meat and Wool New Zealand Central Progeny Test (CPT). Over the past six seasons, a total of 120 leading industry sires, comprising 14 different breeds, have been mated via artificial insemination. CPT rams are genetically connected via common sires ...Continued }, issn = {1176-5283}, author = {McLean NJ and Dodds KG and Knowler KJ and Jopson NB and Behrent M and Logan CM and Muir PD and Shackell GH and McEwan JC} } @conference {41794, title = {Association between milk protein concentration and preceding reproductive performance in Holstein-Friesian heifers and cows in Australia}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {69-72}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {Milk protein concentration (MP\%) has been associated with reproductive performance amongst parous dairy cows. This study aimed to assess whether early lactation MP\% of primiparous cows was associated with prior reproductive performance, and to compare the strength of the association between MP\% and previous reproductive performance in nulliparous heifers with that in multiparous cows. Primiparous (n = 918 in 35 herds) and multiparous (n = 4,242 in 64 herds) Holstein-Friesian cows with milk production/composition records and sire genetic information in seasonally calving herds were selected from the InCalf database. The date for each herd{\textquoteright}s planned start of calving (PSC) was calculated as being 282 d after the date breeding started. The interval between a herd{\textquoteright}s PSC date and each cow{\textquoteright}s actual calving date (PSC - CI) will therefore reflect time to conception during the previous breeding period. Higher MP\% was positively associated with shorter PSC-CI in both primiparous and multiparous cows. Across the range of cows that had a MP\% that was {\textpm} 0.5\% of the herd{\textquoteright}s mean MP\%, those with the lowest MP\% had an average PSC-CI that was either 13 d or from 28 to 32 d later in primiparous or multiparous cows, respectively. These associations were likely due to biological determinants present before and during the cow{\textquoteright}s breeding period that were associated with both reproductive performance and subsequent MP\%. Since these determinants affected the reproductive performance of non-lactating heifers, some of the associations with MP\% were not related to lactation-specific factors even though these same factors may have increased the effect of low MP\% on the reproductive performance of the multiparous Holstein-Friesian cows. }, issn = {1176-5283}, author = {Fahey J and Morton JM and Macmillan KL} } @conference {42075, title = {Carcass and meat quality characteristics in young deer stags of different growth rates}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {174-177}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {Fourteen male yearling red deer from the same cohort were included in this study. Seven of these animals were fast growing and reached slaughter live weight in late June (fast growing group), while the second group of seven deer did not reach slaughter live weight until early December (slower growing group). All animals were slaughtered according to standard protocol. Carcass composition was determined by computed tomography scanning. Water-holding capacity, meat pH, tenderness and sarcomere length were measured in samples (M. longissimus) at 1 day post slaughter and in samples kept in chilled storage at -1.5 {\textdegree}C for three weeks. Eating quality of the meat was evaluated in consumer preference tests. Slower growing deer were heavier (P = 0.02) and had more fat in the shoulder (P = 0.01) and loin (P = 0.001) cuts than fast growing deer. Meat from fast growing deer had lower pH values (P = 0.01), lower cooking loss (P = 0.04) and longer sarcomere lengths (P = 0.002) than slower growing deer. Consumers judged the flavour of venison from fast growing deer to be best (P = 0.005), although interactions between the sensory attributes and the consumer{\textquoteleft}s experience of venison affected their assessment. }, issn = {1176-5283}, author = {Wiklund E and Asher GW and Archer JA and Ward JF and Littlejohn RP} } @conference {41773, title = {Characterization and establishment of embryonic stem cell - like cell lines from in vitro produced buffalo (Bubalus bubalis) parthenotes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {4-7}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {Embryonic stem cells (ESC) provide potentially unlimited cell numbers for gene targeting, providing great value to agriculture and medicine. This study was conducted to isolate and characterize parthenogenetic ESC (pESC)-like cells from in vitroproduced buffalo parthenotes. A total of 100 blastocysts were produced through chemical activation. For pESC culture, 20 blastocysts were left intact, while the rest was dissociated mechanically or enzymatically, to isolate inner cell mass (ICM) cells from 44 hatched and 36 non-hatched blastocysts, respectively. ICM cells were seeded and cultured on mitomycin-C treated feeder layers of buffalo fetal fibroblasts. Primary cell colonies formed three tofour days after ICM seeding. Colony formation was significantly lower from intact blastocysts (3/20 (15\%)) than from ICM cultures (39/80 (49\%)) with hatched blastocysts being better starting material than non-hatched ones (30/44 (68\%) versus 9/36 (25\%), respectively). Up to passage nine, two mechanically isolated pESC-like lines remained viable and expressed specific markers such as alkaline phosphatase activity, as well as Nanog and Oct-4 mRNA. Cells formed embryoid bodies in suspension culture. It has been shown it is possible to isolate buffalo pESC-like cells from parthenogenetically developed embryos and maintain the culture in vitro for a prolonged period of time.}, issn = {1176-5283}, author = {Verma V and Chauhan MS} } @conference {42043, title = {Comparative methane emissions from cattle, red deer and sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {59-62}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {Methane (CH4) production (g CH4/d) and yields (g CH4/kg dry matter intake (DMI)) from groups of 11 non-lactating dairy cattle, sheep and red deer were compared in January and June of 2007. During each period, methane emissions measured using the SF6 tracer technique, were measured over four days following 10 days of acclimatisation. All animals were individually housed in metabolism cages and fed ensiled lucerne chaff at a rate of 1.2 times estimated energy requirements according to Australian feeding standards. Total daily methane production from cattle (140.4 g CH4/day) was greater than deer (31.5 g CH4/day) which was greater than sheep (18.3 g CH4/day) (P<0.001) and methane yield from cattle (20.6 g CH4/kg DMI) was greater than sheep (18.4 g CH4/kg DMI) which was greater than deer (16.5 g CH4/kg DMI) (P<0.001). A significant interaction of species by season was driven by the higher methane production and yield of cattle in winter compared with summer (P<0.001). The findings of this experiment show that methane emissions can differ between ruminant species at the same time on the same diet. Reasons for these differences are yet to be elucidated. }, issn = {1176-5283}, author = {Swainson NM and Hoskin SO and Clark H and Pinares-Patino CS and Brookes IM} } @conference {42063, title = {Comparison of lameness and hoof horn puncture resistance of New Zealand Friesian and Jersey cross Friesian dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {128-129}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {Sole lesions have been found to be one of the most common causes of lameness in both New Zealand (Chesterton, 2004) and the United Kingdom (Logue, 1999). In most studies it was found that these hoof horn lesions develop in postpartum animals and in hind claws (Greenough \& Vermunt, 1991) and that these are associated with a significant reduction in the puncture resistance of the hoof (Winkler \& Margerison, 2006). There has been some reference to lower levels of lameness occurring in Jersey and Jersey cross bred cattle, compared with Holstein Friesian dairy cattle ...Continued }, issn = {1176-5283}, author = {Lethbridge LA and Margerison JK and Reynolds GW and Laven R and Brennan CS} } @conference {41774, title = {Comparison of mastitis prevalence between an organic and conventional dairy herd from 2004 to 2006}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {8-11}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {This study compared mastitis bacteriology and somatic cell counts (SCC) between an organic and a conventional dairy herd, each managed as a pastoral-based system, in the 2004/05 and 2005/06 seasons. Single quarter foremilk samples taken from both herds at calving, 14 days post-calving, mid-lactation and dry-off were cultured for bacteriological analysis. Individualcow SCC were obtained from monthly herd tests. The percentage of cows infected with Staphylococcus aureusand Streptococcus uberiswas generally higher in the organic herd than the conventional herd. However, these differences were only significant for S. aureusat midlactation 2005/06, when 56\% of the organic herd was infected compared to 23\% of the conventional herd (P <0.05), and for Str. uberisat dry-off 2005/06, when 7\% of the organic herd was infected but none of the conventional herd (P <0.001). The organic herd had a significantly higher mean lactation back transformed SCC than the conventional herd, in 2004/05 (96,921 vs. 75,608 cells/mL, P <0.05) and 2005/06 (103,968 vs. 63,096 cells/mL, P <0.0001). The 2004/05 season was the first time that a significant difference in mean SCC between the organic and conventional herds had been measured, since the organic and conventional dairy systems comparison trial was established in 2001.}, issn = {1176-5283}, author = {McLeod KLM and Holmes CW and Morel PCH and Dowson KR and Thatcher A and Shadbolt NM and Kelly TC} } @conference {41814, title = {Comparison of Romney sheep selected for different roundworm parasite-related traits}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {138-141}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {Romney sheep selected for resistance to nematode infection, resilience to nematode challenge, or an index combining these traits, were evaluated alongside an unselected control line. Data from lambs born between 2000 and 2006 were analysed. Lambs grazed together, within sexes, while exposed to natural parasite challenge of predominantly Trichostrongylus sp. and Teladorsagia sp. Relative to the Control, the Resilient line was heavier at weaning (+7.6\%) and in autumn (+14.5\%), had 5.6\% higher yearling greasy fleece weight (YGFW), and less dags (lower score) at 5 months of age by 0.72 standard deviations (SD) (all P <0.01). As expected, the two lines had similar post-weaning faecal worm egg count (FEC1). Compared with the Control, the Resistant line was lighter at weaning (-8.6\%) and in autumn (-8.0\%), had 14.9\% lower YGFW and a higher dag score by 0.22 SD, whilst FEC1 averaged 16\% of the Control value (all P <0.001). Performance of the Index line in growth and YGFW was 3.5 to 6.8\% above that expected in a Resistant x Resilient cross. Conversely, FEC1 in the Index line was at least 31\% higher than expected for a cross. We conclude that combining genes for resilience and low FEC by index selection is feasible. }, issn = {1176-5283}, author = {Wheeler M and Morris CA and Bisset SA} } @conference {42064, title = {Counting infective-stage nematode larvae in rumen fluid as an indicator of parasite challenge in grazing sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {130-133}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {The aim of this study was to evaluate rumen fluid sampling as a novel method for quantifying nematode challenge encountered by grazing sheep. In Experiment 1, rumen fluid samples were seeded with known numbers of third stage infective larvae (L3) of Teladorsagia circumcincta, Trichostrongylus colubriformis and Cooperia curticei. Immediate recovery rates averaged 92\% (Coefficient of variation, 13\%), 53\% (15\%) and 50\% (30\%) for each species respectively. Recovery rates from rumen fluid stored at 7{\textdegree}C decreased to 44\% (29\%), 33\% (18\%) and 0\% (0\%) after 72 hours. In Experiment 2, 15 ewe hoggets maintained indoors were dosed with 5,000 L3 T. circumcincta and 5,000 L3 T. colubriformis. At 1, 2 and 12 hours after dosing the numbers of L3 recovered from the rumen fluid were 0.2 (125\%), 0.16 (145\%) and 0.01 L3/mL (300\%) respectively. In Experiment 3, rumen fluid samples were taken from small groups of lambs grazing four paddocks with variable herbage infestation rates of mixed species of L3. Species composition of L3 on the herbage and in the rumen fluid was T. circumcincta 8\% and 0\%; T. colubriformis 27\% and 19\%; C. curticei 0\% and 5\%; Nematodirus spp. 63\% and 69\% and Haemonchus contortus 2\% and 9\%. A significant number of technical challenges remain before the method has a practical application. }, issn = {1176-5283}, author = {Litherland AJ and Deighton DL} } @conference {41821, title = {Does calf genotype influence milk yield of red deer hinds ?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {170-171}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {New Zealand deer farming systems utilise Cervus elaphus subspecies and crossing genotypes is a common tool to gain a productive advantage. One of the most common crosses is that of a stag with a high content of North American Wapiti (C. e. manitobensis, nelsoni, roosevelti) over the traditional New Zealand (NZ) red hind of English or Scottish origin (C. e. scoticus) for venison production, with on the aim of attaining slaughter live weight ...Continued }, issn = {1176-5283}, author = {Ward JF and Archer JA and Asher GW and Barrell GK and Littlejohn RP} } @conference {41798, title = {Economic modelling of the comparative performance of Jersey x Holstein - Friesian crossbred cows in Victorian Holstein-Friesian herds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {84-87}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {An economic model was developed to compare two different farm systems using the production results and reproductive performance figures derived from an observational study of 14 seasonally calving dairy herds in Victoria. The farm systems modelled were a crossbred herd comprising Jersey x Holstein-Friesian and Holstein-Friesian x (Jersey x Holstein-Friesian) breed types and a herd of Holstein-Friesian cows with farm operating profit as the outcome. A direct comparison of the two farming systems demonstrated a clear advantage in operating profit that averaged A$21,194 for the 267 cows in the crossbred herd compared to the 252 cows in the Holstein-Friesian herd. The difference in profit was due to the higher potential stocking rate of the crossbred herd (2.27 vs 2.15 cows/ha) because of their lower live weight (1 crossbred cow = 0.93 Holstein-Friesian cow) and superior reproductive performance (84\% vs 77\% pregnancy rate after 14 weeks) resulting in longer survival and reduced investment in replacement rearing costs. }, issn = {1176-5283}, author = {Pyman MF and Malcolm W and Macmillan KL} } @conference {41807, title = {Effect of dietary protein on liveweight gain in parasitised cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {113-116}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {The interaction between parasitism and crude protein (CP) nutrition on calf liveweight gain (LWG) was investigated. One hundred and twelve calves were either administered 21,000 parasite larvae (73\% Cooperia oncophora, 16\% Ostertagia ostertagi, 11\% Trichostrongylus axei) twice per week or drenched fortnightly with anthelmintic for 12 weeks. Calves grazed ryegrass pastures and received 40\% of their diet as either low (15\% CP) or high (26\% CP) protein pellets. Half of the calves switched diets after six weeks. All treatments averaged a liveweight gain of at least 1 kg/d. After 12 weeks non-parasitised calves were 13 (standard error of difference (SED 2.0)) kg heavier than parasitised calves (P <0.001), and calves fed a high protein supplement were 12 (SED 2.8) kg heavier than those fed low protein supplement (P <0.001). There was no interaction between diet and parasitism (P = 0.74). Subsequentlycalves grazed together for a further 12 weeks with no supplements or parasite dosing. The liveweight advantage of the high protein supplement was lost, while non-parasitised calves maintained a liveweight advantage of 15 (SED 4.9) kg (P <0.01). While protein supplementation did not affect faecal egg count or blood pepsinogen it has the potential to improve LWG with less reliance on anthelmintics under field conditions.}, issn = {1176-5283}, author = {Burggraaf VT and Puha MR and Adler AA} } @conference {41800, title = {Effect of dry cow management on teat end bacterial contamination}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {92-95}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {Two stock management practices were investigated for their effect on transfer of bacteria from the environment onto teat ends of dry dairy cows. Cows (n = 20) were required to walk or trot along races (1.2 km) deemed to be "clean" or "dirty". Cows walked along "clean" or "dirty" races were similar in dirtiness of the udder, and bacterial loading of the teats. Cows that trotted along {\textquoteleft}dirty{\textquoteleft} races showed a significant increase in degree of dirtiness of the teats and legs, and increased contamination of teats with coliform bacteria. Cows grazed for 24 hour periods using standard break-fencing systems, with (n = 20) or without (n = 20) the addition of back-fencing were assessed for the number and type of bacteria present on teat-ends. Cows that grazed paddocks with back-fencing had visually dirtier udders, but there was no difference in bacterial contamination of teats compared to those cows grazed without back-fencing. These studies suggest that the risk of bacterial contamination, and by extrapolation, risk of intra-mammary infection, may be mitigated by the speed with which cows are moved along races. However, grazing on muddy, soiled paddocks should not be discounted as a significant risk factor for mastitis. }, issn = {1176-5283}, author = {Turner S-A and Williamson JH and Lacy-Hulbert SJ} } @conference {41776, title = {Effect of forage allowance and forage system during the dry period on the performance of dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {16-19}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {Sixty multiparous Holstein-Friesian dairy cows were allocated one of three forages (fodder beet, kale or grass silage) at one of two feeding allocations (high and low). Cows offered the high allowance system received 9 kg of kale or fodder beet DMin-situplus 5 kg of bale grass silage DM per day,or ad libitumgrass silage offered indoors. Cows on the low allowance system were offered 6 kg of kale or fodder beet DMin-situplus 3.5 kg of bale grass silage DM per day,or 9.5 kg of grass silage DMoffered indoors. Treatments were imposed for 70 {\textpm} 16 days before parturition. Post-partum,all cows were turned out to pasture and received 14 kg of perennial ryegrass DM plus 4 kg of concentrate/cow/d for the first five weeks of lactation. Cows offered grass silage had a greater gain in body condition score pre-partum than animals offered kale or fodder beet systems. Cows offered the fodder beet system pre-partum had a greater fat yield compared to those offered kale and a greater protein yield compared to those offered grass silage, resulting in a 9 \% increase in solids corrected milk yield during the first five weeks of lactation.}, issn = {1176-5283}, author = {Keogh BK and French P and McGrath T and Storey T and Mulligan FJ} } @conference {42049, title = {Effect of genotype and concentrate supplementation on dairy product mix and the value of milk produced by grazing dairy cows during an extended lactation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {79-83}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {Dairy product mix and milk value were investigated in Holstein-Friesian cows of New Zealand or overseas origin that grazed pasture and were supplemented with 0, 3 or 6 kg DM concentrate/cow/day during a 600-day extended lactation. A dairy product supply chain model was used to predict relative changes in dairy product mix and milk value during the "extended period" (300 to 600 days in milk) compared with the "normal period" (0 to 300 days in milk). Cow genotype and level of concentrate supplement affected dairy product yields, with little consistency of effect between "normal" and "extended" periods. Milk produced during the "extended period" resulted in more cheese, butter, butter milk powder, casein, and whey protein concentrate, but less whole milk powder, skim milk powder and whey milk powder compared to the "normal period". The overseas strain and those cows receiving higher levels of concentrates had less of a decline in whole milk powder yields associated with the "extended period". Milk value ($/L), was predicted to be 20.8\% higher during the "extended period" compared with the "normal period". These results indicate that extended lactations may improve the dairy product mix and milk value following processing. }, issn = {1176-5283}, author = {Turner S-A and Phyn CVC and Kolver ES and Aspin PW and Lopez-Villalobos N} } @conference {42055, title = {Effect of genotype and diet on feed conversion efficiency of dairy cows during a 600-day extended lactation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {100-104}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {This study investigated the effect of genotype and diet on the gross feed conversion efficiency (FCE) of cows milked for 600-day extended lactations (24-month season) compared with 300-day lactations (12-month season). North American (NA) and New Zealand (NZ) Holstein-Friesians (HF) grazed pasture and were supplemented with either 0, 3 or 6 kg DM concentrate/cow/day. In a normal 12-month season, gross FCE was greater for NZ HF compared with NA HF cows when fed 0 or 3 kg DM concentrate (96 and 104 vs. 90 and 99 kg milksolids (MS)/t dry matter intake (DMI), respectively), but similar when fed 6 kg DM (101 kg MS/t DMI). However, during an extended 24-month season, NZ HF cows had a lower gross FCE than NA HF when fed 6 kg DM concentrate (86 vs. 99 kg MS/t DMI, respectively) and similar FCE when fed 0 or 3 kg DM (85 and 94 vs. 86 and 99 kg MS/t DMI, respectively). Regardless of diet, gross FCE in an extended lactation was 98\% of that obtained in a normal season for NA HF cows, but only 88\% for NZ HF, indicating that NA HF are better suited to converting feed into high MS production in extended lactations. }, issn = {1176-5283}, author = {Phyn CVC and Clark C and Aspin PW and Kolver ES} } @conference {41785, title = {Effect of MyoMAX on carcass lean and fat}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {43-44}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {Previous research has identified quantitative trait loci (QTL) for increased lean meat yield and decreased fat in similar regions of sheep chromosome 2, in New Zealand and Belgian Texels (Broad et al., 2000; Johnson et al., 2005; Laville et al., 2004; Marcq et al., 2002). In the case of the Belgian Texels it has been demonstrated that a single G to A transition ...Continued }, issn = {1176-5283}, author = {Bain WE and PL Johnson and Greer GJ and Dodds KG and McLean NJ and McLaren RJ and Galloway SM and Van Stijn TC and McEwan JC} } @conference {42031, title = {Effect of offering differing levels of milk and plant extracts on feed intake , growth and development of New Zealand Holstein-Friesian and Jersey crossbred dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {27-28}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {Calving dairy heifers at 2 years of age at 85 to 90 \% of their mature live weight and being mated at 65\% of their mature live weight, has been found to increase lifetime productivity (Margerison \& Downey, 2005). Recent research has focused on increasing dairy calf liveweight gain and development, while minimising body fat deposition, particularly in mammary parenchyma (Sejrsen, 2005; Brown et al., 2005), by increasing feeding levels during the prepubertal period with differing sources and levels of energy and protein, and the use of probiotics and natural plant extracts to replace antimicrobials (Hill, 2005; Tannan, 2005). The aim of this research was to ... Continued }, issn = {1176-5283}, author = {Margerison JK and Lethbridge LA and Reynolds GW} } @conference {41818, title = {Effect of once daily milking on milk flavour chemistry}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {162-163}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {Indole and skatole have been associated with the "pastoral" flavour of New Zealand dairy products (Bendall, 2001). They occur at elevated levels in milk from pasture-fed cows in New Zealand, particularly in early to mid spring (Lane et al., 2002). On-farm management approaches to control skatole levels in milk could provide benefits to the industry for particular products and ...Continued }, issn = {1176-5283}, author = {Lane GA and Fraser K and Yu M and Pacheco D and Dalley DE and Hofmann LA} } @conference {42058, title = {The effect of palm kernel expeller as a supplement for grazing dairy cows at the end of lactation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {111-112}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {Palm kernel expeller (PKE) is a solid byproduct from the palm oil. In New Zealand it is used as a supplementary feed on dairy farms to fill short term pasture deficits and according to MAF (2007), over 350,000 tonnes of PKE was imported into New Zealand during 2007. Despite its growing use as a feedstuff for ruminants in New Zealand, information is scarce about the nutritional value of PKE and ...Continued }, issn = {1176-5283}, author = {Dias FN and Burke JL and Pacheco D and Holmes CW} } @conference {41813, title = {Effects of facial eczema on skatole detoxification efficiency in dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {134-137}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {Facial eczema (FE) is a disease caused by the fungal toxin sporidesmin, which upon ingestion by dairy cows can cause liver damage in susceptible animals. Skatole is formed in the rumen by the breakdown of dietary protein, absorbed into blood and is cleared by metabolism in the liver to 3-methyloxindole (MOI) and 3-hydroxy-3-methyloxindole (HMOI) and products of further oxidation and conjugation. In this study we have determined the concentrations of skatole, MOI and HMOI in the blood of dairy cows selected for their "high" gamma-glutamyltransferase (GGT) and "low" GGT in autumn and spring. Significant differences in skatole and MOI median concentrations were found in the autumn blood between the high and low GGT groups (skatole: 11.9 and 1.1 ng/mL respectively, P <0.001; MOI: 23.9 and 11.9 ng/mL respectively, P <0.05) although there was no difference in blood HMOI levels. Similar trends were observed for animals with high GGT in both autumn and spring when compared to low autumn and spring GGT. Animals with high autumn GGT and low spring GGT also contained increased median concentrations of skatole and MOI in the spring blood compared to the low autumn and spring GGT group, suggesting a lingering effect of FE damage on liver detoxification efficiency not detected by measuring spring GGT levels. }, issn = {1176-5283}, author = {Fraser K and Lane GA and Yu M and Morris CA and Cullen NG} } @conference {41786, title = {Energy rather than protein content of hind intake determines growth rate of reed deer calves}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {45-46}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {Live weight gain of red deer within the first 3 to 4 months of their life plays a major part in determining the efficiency of venison production systems. Over this period young deer are largely dependant on their dam for nutrition. It is often difficult to achieve growth rates greater than 400 g/d in New Zealand because red deer lactation coincides with deteriorating pasture quality. However, calf growth rates of up to 700 g/day have been achieved over late lactation when }, issn = {1176-5283}, author = {Scott IC and Archer JA and Asher GW and Stevens DR and Ward JF and Littlejohn RP and Lach JE} } @conference {41808, title = {Epidemiology of Johne{\textquoteright}s disease in farmed red deer ( Cervus elaphus ) in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {117-121}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {Johne{\textquoteleft}s disease, caused by Mycobacterium avium subsp paratuberculosis (M. ptb), has emerged as a significant cause of losses on deer farms in New Zealand. It causes outbreaks of fatal clinical disease in young deer eight to 15 months of age, sporadic deaths in adults and production losses due to poor growth rates in yearlings, reduced calving percentages in hinds, reduced velvet production in stags, interference with tuberculosis testing and tuberculosis-like lesions in gut lymph nodes at slaughter. Although bovine and ovine strains have been isolated from deer, the bovine strain is more pathogenic and is responsible for the outbreaks of serious disease in young deer. Clinical disease results from heavy early challenge of young deer with the bovine strain. Mature animals are relatively resistant to infection. Calves are generally infected via the oral route from contaminated pasture and water. Intrauterine transmission to the foetus occurs commonly in clinically and subclinically infected hinds and infected milk may also play a role in transmission. Deer-to-deer transmission appears the most common route, although cattle-to-deer and sheep-to-deer transmission may occur. The role of wildlife is not known. Resistance to Johne{\textquoteleft}s disease has a genetic component, which appears to be related to resistance to bovine tuberculosis. }, issn = {1176-5283}, author = {Mackintosh CG} } @conference {41781, title = {Expression of innate immune response genes in mammary epithelia following stimulation of lipopolysaccharide or Escherichia coli}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {31-32}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {The innate immune system is essential for keeping the bovine mammary gland disease free. A number of innate immune response genes are expressed in bovine mammary epithelial cells (bMEC), suggesting it contributes to defence against pathogens (Rainard \& Riollet, 2006). These responses may play a key role in determining susceptibility to mastitis. The aim of this project was to investigate the expression in bMEC of specific innate immune genes in response to Escherichia coli ...Continued }, issn = {1176-5283}, author = {Stockum C and Haigh BJ and Meyer HHD and Bruckmaier RM and Wheeler TT and Singh K} } @conference {41819, title = {Factors affecting colour stability of fresh chilled lamb meat}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {164-165}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {An increasing proportion of New Zealand lamb meat is shipped to the European Union market as chilled rather than frozen product, with 29\% exported as chilled product in 2005/06 (Anon, 2006). Once chilled lamb reaches this market it is further processed, with the lamb meat entering the retail market approximately eight weeks after slaughter. A major selection criterion for retail purchasers is the colour of the meat on display. Most consumers prefer bright red ...Continued }, issn = {1176-5283}, author = {PL Johnson and McLean NJ and Bain WE and Young E and Campbell AW} } @conference {42061, title = {Field test of production traits in genetically correlated with zearalenone resistance in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {122-123}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {Zearalenone is a naturally occurring toxin from the Fusarium fungus which grows on pastures in autumn. The toxin has been found in New Zealand from Northland to Southland (Garthwaite et al., 1994), but high concentrations are particularly common in the Gisborne/East Coast region. The toxin interferes with reproductive function in susceptible sheep (Smith et al., 1986), reducing fertility, ovulation rates and thus lambing percentages. Under research conditions with Romney sheep at Ruakura Research Centre, we have developed a protocol ...Continued }, issn = {1176-5283}, author = {Amyes NC and Morris CA} } @conference {41784, title = {Gene expression profiling of wool follicle growth cycles by cDNA microarray}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {39-42}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {Wool growth in Wiltshire sheep was synchronised by daylength manipulation to allow identification of genes that are regulated during transitions in the wool follicle cycle. Pair-wise comparisons between growing and resting phases were conducted using both direct and indirect cDNA microarray analysis. The two approaches were well correlated at three different levels: overall similar patterns of gene expression, detection of changes in keratin gene expression, and reduced differential expression between closer cycle stages. Using more slides, the indirect approach identified more expressed sequence tags (ESTs) (indirect 1132, direct 444), and had higher coverage of wool keratins (indirect 78\%, direct 42\%). This study demonstrates the usefulness of cDNA microarray for expression profiling in whole skin. Further characterisation of genes identified by this work, particularly the smaller sets of ESTs derived from comparisons at early stages of follicle regression and regrowth, would improve our understanding and provide leads for alternative wool harvesting technology or enhancing wool growth. }, issn = {1176-5283}, author = {Yu Z-D and Gordon SW and Pearson AJ and Henderson HV and Craven AJ and Nixon AJ} } @conference {42074, title = {Genetic parameters for growth in Wapiti deer farmed in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {172-173}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {The New Zealand deer industry commonly uses "Wapiti" type deer as terminal sires mated to "red" hinds in venison production systems. The terms "Elk" and "Wapiti" are commonly used almost interchangeably in the New Zealand deer industry to describe subspecies of red deer originating in North America (Cervus elaphus subspecies manitobensis, roosevelti and nelsoni). These subspecies are approximately twice the mature body size of "red" deer ...Continued }, issn = {1176-5283}, author = {Archer JA and Ward JF and Fisher PJ and Glass BC} } @conference {42051, title = {Genetics of residual energy intake in Irish grazing dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {88-91}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {The objective of this study was to investigate the genetics of residual net energy intake (RNEI) in grazing Holstein-Friesian cows. RNEI was defined as net energy intake minus predicted net energy requirements using the unit{\'e} fourrag{\`e}re lait (UFL) system. Net energy intake from grass and concentrate was estimated up to four times per lactation on 1,111 lactations from 463 cows on an experimental farm in Southern Ireland. Grass dry matter intake was estimated using the n-alkane technique. Lactation curves for milk, fat, protein, lactose and live weight were modelled with splines using weekly measures. A random regression was used to estimate residual, additive genetic and permanent environmental variances for RNEI and breeding values at Day 60 for each cow. Heritability for RNEI across lactation varied from 0.05 at 30 days in milk to 0.38 at 296 days in milk. Genetic parameters for RNEI obtained in this study are in agreement with those obtained under indoor conditions. Comparative performance between cows of low and high RNEI breeding value at Day 60 agrees with results obtained in beef cattle selected for high or low residual feed intake showing similar productivity but higher feed conversion efficiency in cows selected for low residual feed intake.}, issn = {1176-5283}, author = {Lopez-Villalobos N and Berry DP and Horan B and Buckley F and Kennedy J and O{\textquoteright}Donovan M and Shalloo L and Dillon P} } @conference {41802, title = {Heritability of IGF-1 and its genetic correlation with milk yield in Holstein-Friesian cows in selected Victorian herds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {98-99}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {Insulin-like growth factor-1 (IGF-1) is a small peptide, produced mainly in the liver. It controls the growth and differentiation of many cell types through stimulation of the cell cycle (Rechler \& Nissley, 1990). IGF-1 has been implicated as being involved in many biological processes and is thought to be related to milk production and reproductive potential of the dairy cow due to its association with the partitioning of nutrients among biological functions (Bauman \& Currie, 1980) and its direct stimulatory affect on the ovaries (Spicer et al., 1993). ...Continued }, issn = {1176-5283}, author = {Stirling TE and Stockdale CR and Macmillan KL} } @conference {41816, title = {High crude protein in autumn pasture does not impair reproductive performance in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {156-157}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {Embryos exposed to ammonia may degenerate or their growth enhanced (McEvoy et al., 1997). Kelly (1982) reported reproductive wastage of 24.9\% in South Island sheep. New Zealand pastures contain high concentrations of crude protein (Chaves et al., 2002) but whether reproductive wastage can partly be explained by ammonia and/or urea toxicity from high protein pasture is unknown. The aims of the present study were to determine the effect of plasma urea concentration on ovulation rate, embryo survival, conception rate and lamb birth weight in ewes joined with the ram on ...Continued }, issn = {1176-5283}, author = {Madibela OR and Nicol AM and Sykes AR and Jay NP} } @conference {41824, title = {Indicators for early detection of ecchymosis ( blood splash ) in fallow deer ( Dama dama ) carcasses}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {178-182}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {Ecchymosis is a haemorragic syndrome that appears as small dark spots on the surface of various muscles of a carcass and some organs. It is considered a meat quality defect. In this study eight fallow deer carcasses were completely dissected. Hindquarter muscles showed a significantly higher incidence of ecchymosis compared with forequarter muscles. The most affectedmuscles were the primal cuts from the hindquarter including the striploin. When this information was applied to a wider study of 963 fallow deer carcasses 23.1\% had low to moderate ecchymosis in the left round (M. vastus lateralis). In all cases this muscle was a reliable indicator of the presence of ecchymosis in the loins and/or other hind leg primals. In the same carcasses visceral organs such as lung and heart were unreliable indicators of the presence of ecchymosis in skeletal muscles. Castrated bucks were most likely to exhibit ecchymosis followed by does and bucks (P = 0.02).An on-line inspection system for fallow deer was recommended which included an in situinspection of the left round as an accurate means of determining ecchymosisincidence in other valuable commercial cuts.}, issn = {1176-5283}, author = {Mulley R and Wiklund E and Falepau D} } @conference {41778, title = {Indole and skatole as markers for nitrogen utilisation in dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {23-26}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {Indole and skatole are products of amino acid degradation in the rumen which could be useful to monitor protein utilisation in grazing ruminants. Two groups ("1970s" strain and "current" strain) of mixed age Holstein Friesian cows were housed indoors and fed cut pasture for 21 days. Concentrations of indole and skatole in milk fat and of milk urea nitrogen were determined. No significant differences were observed between strains of cow for indole and skatole concentration in milk fat, but they were different (P<0.01) between sampling dates. Both indole and skatole had moderate positive (r ~0.50) correlation with the rumen degradable protein (RDP) balance, whilst skatole had a weaker (r ~0.30) correlation with crude protein intake, metabolisable protein supply and RDP supply. Indole and skatole concentrations in milk fat were more closely correlated to the estimated RDP balance in the rumen than milk urea. A large proportion of individual animal variation in milk metabolites remains unaccounted for by protein intake, and may relate to individual differences in detoxification and elimination of indole and skatole. }, issn = {1176-5283}, author = {Pacheco D and Lane GA and Fraser K and MacDonald KA and Back PJ} } @conference {42029, title = {Inheritance of chondrodysplasia in Texel sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {20-22}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {A skeletal chondrodysplasia (noncancerous abnormal cell growth affecting cartilaginous tissues) characterized by dwarfism and angular deformity of the forelimbs has been recognized in Texel and Texel cross lambs. Some affected lambs have normal co-twins indicating the disease is likely to be of genetic origin. This study outlines the mode of inheritance of the disorder. Three affected rams were mated to 221 unaffected ewes to generate 123 daughters, which were backcrossed by multiple sire mating with their sires the subsequent season to produce 83 lambs for evaluation. The time course of the morphological progression of the disease was recorded. Of the 46 lambs that were successfully diagnosed, 22 were affected with the condition and 24 were unaffected. This was consistent with a 50:50 ratio expected for recessive inheritance in a backcross between affected and carrier animals. Within sexes, 11 males (24\%) and 11 females (24\%) were affected with 10 males (22\%) and 14 females (30\%) were unaffected. This was not different (P<0.05) from a 0.25 proportion for autosomal recessive inheritance. Variation in the age of onset (16 days {\textpm} 7 days) and severity of clinical expression suggests variable penetrance, with semi-lethality. }, issn = {1176-5283}, author = {Byrne TJ and Blair HT and Thompson KG and Stowell KM and Piripi S} } @conference {41801, title = {Jersey cows milked once-a-day can produce 1,200 kg milk solids per hectare}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {96-97}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {While dairy cows are generally milked twice-a-day (TAD) in New Zealand, more farmers are adopting a once-a-day (OAD) milking routine to improve their lifestyle, reduce farm costs and improve animal welfare. Clark et al. (2006) reported that the yield of milksolids (MS) from Jersey cows was less affected (-19.9\%/cow) by OAD milking than the MS yield from Holstein-Friesian cows (-29.4\%/cow). Jersey cows milked OAD in Taranaki between 2000 and 2004 averaged 222 kg MS/cow and 979 kg MS/ha (Clark et al., 2006). In the 2006/07 season average per cow production from cows milked TAD in New Zealand was 330 kg MS ...Continued}, issn = {1176-5283}, author = {Dalley DE and Clough JW and Hofmann LA and Phyn CVC and Clark DA} } @conference {42045, title = {Liveweight and body condition of single- and twin-bearing Merino ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {67-68}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {

While dairy cows are generally milked twice-a-day (TAD) in New Zealand, more farmers are adopting a once-a-day (OAD) milking routine to improve their lifestyle, reduce farm costs and improve animal welfare. Clark et al. (2006) reported that the yield of milksolids (MS) from Jersey cows was less affected (-19.9\%/cow) by OAD milking than the MS yield from Holstein-Friesian cows (-29.4\%/cow). Jersey cows milked OAD in Taranaki between 2000 and 2004 averaged 222 kg MS/cow and 979 kg MS/ha (Clark et al., 2006). In the 2006/07 season ...Continued

}, issn = {1176-5283}, author = {van Reenen EH and Kenyon PR and Sherlock RG and Hickson RE and Morris ST} } @conference {41795, title = {Luteal function in pregnant and non-pregnant non-cycling inseminated cows ( Phantom cows )}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {73-76}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {Cows that do not return to oestrus within 24 days of insemination but are retrospectively diagnosed as not pregnant (non-return, non-pregnant or "Phantom" cows), frequently have a functional corpus luteum (CL) that does not regress. In this study, luteal function around the time of pregnancy diagnosis was compared between pregnant cows and "Phantom" cows with a CL. Cows in two dairy herds that had not returned to oestrus following first insemination were pregnancy tested by ultrasound 5 weeks after insemination. Final analyses included 17 pregnant cows that were cycling normally before being inseminated (CYCP); 22 pregnant cows that had been treated for anoestrus (ANP); and 11 "Phantom" (PC) cows that had not cycled since first insemination and were not pregnant. Blood and CL samples that were collected from each cow between 34 and 38 days after first insemination were assayed for progesterone (P4). Luteal P4 concentrations were similar in pregnant and PC cows (101.6 {\textpm} 9.9, 100.7 {\textpm} 8.9 and 98.9 {\textpm} 12.4 ng/mg for CYCP, ANP and PC cows). Plasma P4 concentrations were also similar (8.5 {\textpm} 0.5, 7.6 {\textpm} 0.4 and 7.1 {\textpm} 0.6 ng/mL) for CYCP, ANP and PC cows. The absence of a return to oestrus in this group of PC cows was most likely related to pregnancy recognition being followed by embryo death and then associated with a failure of luteolysis. }, issn = {1176-5283}, author = {Bowyer-Smyth JM and Malmo J and Macmillan KL} } @conference {42069, title = {Policy decision framework for conflicting world views on animal welfare issues}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {158-161}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {Animal welfare policies deal with complex issues involving and resulting from, animal management in highly modified environments. How people consider and respond to animal welfare issues is value laden, constrained by the social norms of their peer-groups and influenced by conflicting scientific and popular opinions. In some cases, achieving a consensus about what constitutes the most socially desirable course of action to follow will simply not be possible. Instead, socially-resilient policies forged from mutual respect and understanding may be possible by bringing together the different world views of the conflicting parties in a planning model that enables them each to contribute transparently towards policy formulation. The 4-windows strategy for animal welfare policy formulation described in this paper, when applied to a farming practice of concern, such as lamb castration, can assist an agency like the National Animal Welfare Advisory Committee to address the concerns of social groups outside of traditional scientific thinking and enable them to contribute to the policy process more fully. However, the 4-windows strategy may be more difficult when there is a lack of reliable information about the values and expectations of some social groups. Overall, this approach has implications for the way in which livestock farming in New Zealand may be influenced in the future by current social trends. }, issn = {1176-5283}, author = {Parminter TG} } @conference {42024, title = {Presidential Address 2007: The Society{\textquoteright}s role in being empathetic to the animal production industry}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {1-3}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {Mark Twain once said, "Its better to keep your mouth shut and appear stupid...than to open it and remove all doubt". I considered my strength as President to be more of stewardship than visionary. Alas, it is with some risk to fulfilling Mark Twain{\textquoteright}s prophecy that I continue with this address. I referred to some of the previous Presidential Addresses; to get a feel for what was expected. Certainly, if the Society was to undertake all the {\textquotedblleft}must-do{\textquoteright}s{\textquotedblright} and follow all the visions put forward, we would have made Microsoft Corporation seem like a cake-stall operation by now.}, issn = {1176-5283}, author = {Burke CR} } @conference {41820, title = {Quantification of lactoferrin in milk from New Zealand dairy goats}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {166-169}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {Lactoferrin (Lf), an iron-binding protein, plays a key part in host defence with diverse protective roles in infection and inflammation, including allergy. It is present in most mucosal secretions, including colostrum and milk. To quantify the levels of Lf in milk from New Zealand dairy goats, a sandwich enzyme-linked immunosorbent assay (ELISA) was established. Purified Lf, extracted from goat colostrum, was used to raise antibodies in rabbits and for ELISA standards. The ELISA method involved coating goat Lf antibody onto microtitre plates then sequential addition of standard or test samples, biotinylated-goat Lf antibody and streptavidin-biotin conjugate, with a colorimetric endpoint employing 3,3{\textquoteleft},5,5{\textquoteleft}-tetramethylbenzidine. The intra and inter assay coefficient of variation was 4.1\% and 7.8\%, respectively. Average recovery of added Lf was 104.5\%. Cross reactivity with bovine Lf was 40\% and negligible for other milk proteins tested. In goat milk samples collected over the lactation season, the average Lf concentration was 31.8 {\textpm} 7.3 (standard error of the mean); 33.4 {\textpm} 5.2 and 821.8 {\textpm} 269.4 mg/L, in early, mid- and late season, respectively. An ELISA method has been developed that accurately and reproducibly measures Lf in goat milk samples. Lf levels in New Zealand goat milk are similar to those reported for the cow. }, issn = {1176-5283}, author = {Hodgkinson AJ and Ross KM and Fahey SN and Prosser CG} } @conference {41810, title = {Quantifying parasitic nematode larvae on pasture}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {124-127}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {The aim of this study was to explore sources of paddock and laboratory variability in parasitic third stage larval (L3) tests. Recovery of Teladorsagia circumcincta larvae was greater than Trichostrongylus colubriformis larvae recovery from water (60 vs 43\%; P <0.005), from water contaminated with soil (55 vs 36\%; P <0.03) and from water with pasture (27 and 6\%; P <0.001). Recoveries following seeding with either T. circumcincta or T. colubrifomis L3s onto pasture were similar (44\% vs 56\% respectively). Naturally contaminated pasture samples had similar mean larval number (larvae/kg DM) following extraction using either the plastic bag method (566) or Baermanns extraction (533). Pasture plucking to ground level 50, 100, 150 or 300 times had L3s 1,390 (range 406 - 3,846), 1250 (0 - 4,878), 360 (0 - 1,069) and 450 (182 - 742)/kg DM respectively (P }, issn = {1176-5283}, author = {Litherland AJ and Deighton DL} } @conference {41789, title = {Relative economic value of wool processing parameters for New Zealand strong wool between 2003 and 2007}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {53-56}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {Price trends for a total of 147,416 lots of wool in the strong wool segment of the New Zealand clip sold at auction between 1 July 2003 and 30 June 2007 were analysed by multiple regression analysis to determine the effect on price of five key characteristics known to affect wool processing performance. Changes in exchange rate were allowed for by covariance against the exchange rate of the US dollar on the day of the auction. The residual standard deviation within the data set was 20.4 c/kg clean. Mean values of the slope of the regression, or relative economic value, were 0.4 {\textpm} 0.2 c/ kg clean/mm change in barbe length, -1.9 {\textpm} 0.9 c/kg clean/{\`\i}m change in mean fibre diameter, 2.5 {\textpm} 0.5 c/kg clean/CIE Y value change in brightness, -5.0 {\textpm} 0.6 c/kg clean/CIE Y-Z value change in intensity of yellowness and -16.8 {\textpm} 3.0 c/kg clean/\% change in vegetable matter contamination. These estimated values align closely with values estimated in 1991 for the New Zealand clip as a whole confirming that despite the significant changes that have occurred within the wool processing industry the economic significance of individual wool characteristics to wool processors have not changed. }, issn = {1176-5283}, author = {Sumner RMW and McDermott AK and Cox NR} } @conference {41787, title = {Reticulo-rumen growth and papillae development in farmed red calves from four to twelve weeks of age}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {47-48}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {Ruminants are born with an underdeveloped forestomach (Warner et al., 1956) and as such operate as a monogastric animals until the reticulorumen (RR) and omasum have developed. The development of the rumen from birth to weaning has been well studied in dairy cattle (Heinrichs \& Lesmeister, 2005), but not farmed red deer. Understanding pre-weaning rumen developmental processes is required for feeding programmes aiming to maximise pre-weaning growth rates of young red deer calves for early venison production. This preliminary study aimed to document the changes in rumen growth and papillae development ...Continued }, issn = {1176-5283}, author = {Thompson BR and Hofstra G and Hammond KJ and Mackintosh CG and Hoskin SO and Littlejohn RP and Stevens DR} } @conference {42067, title = {A review of in-utero environmental effects on sheep production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {142-155}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {There has been recent interest in potential intragenerational and intergenerational effects due to pre-natal programming and the implications these may have on production animals, such as the sheep. Evidence for intergenerational effects has been apparent for a significant period of time. The available data indicate that dam nutrition, age, parity, pregnancy rank, live weight, body condition, genotype and fetal genotype, and environmental conditions can all affect fetal development with potential post natal intra-generational consequences. However it is also clear that many of the observed effects in the fetus and young animal do not translate to productive effects in the adult although some models do exist. It is often difficult to compare studies due to differences in the; timing of the manipulation being investigated, live weight and condition of the dam, nutrition of the dam after the manipulation, and management of the young animal post birth. In the future it is probable that farmers will use this information to manipulate the dam in pregnancy to affect the productive performance of future generation(s). Currently few if any models of intergenerational effects exist. Further studies are required to identify consistent intragenerational and intergenerational models which affect productive performance in the adult and that identify the mechanisms responsible for the observed effects. }, issn = {1176-5283}, author = {Kenyon PR} } @conference {41782, title = {SNiP and cut: Quantifying the potential benefits of genomic selection tools for genetic fault elimination in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {33-36}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {Whole genome single nucleotide polymorphism marker (SNP) technologies are rapidly being developed and could well play a role in the future selection of farmed animals. In sheep, work is being carried out to identify SNP{\textquoteleft}s associated with economically important production traits and disease resistance. Stud sheep breeders routinely cull up to 30\% of lambs born due to a variety of faults. Despite this culling pressure, the faults keep occurring, suggesting low heritability, recessive inheritance or incomplete penetration of fault causing genes. The objective of this paper was to identify the potential of SNP fault detection and elimination in sheep. Simulation was used to predict changes in gene frequencies and in an index of genetic merit of production traits over time when between two and 30 SNPs were used to aid selection. The SNPs are assumed to predict the presence of deleterious recessive genes. As selection pressure applied to individual or combination SNPs increased, the rate of increase in production trait genetic merit slowed down. Thus, a balance would be required between the emphasis on SNPs actively used to select against genetic faults, relative to emphasis on genetic merit. This work identified scope for substantial economic benefits from application of SNP technology for removal of faults to both stud breeders and commercial sheep farmers. }, issn = {1176-5283}, author = {Sise JA and Auvray B and Dodds KG and Amer PR} } @conference {41792, title = {Systems and economic analysis of use of maize silage within pasture-based beef production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {63-66}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {The productivity and profitability of the use of maize silage (MS) within pasture-based beef production systems was evaluated using the Farmax Pro{\textregistered} model. Farm systems were simulated based on an intensive one year-old steer production system with two pasture growth patterns (Waikato and Hawkes Bay), three different proportions of the farm in MS production (0\%, 5\% or 10\%) and MS fed either during winter (W) or summer (S). MS cost 13.5 and 16.1 c/kg dry matter (DM) for Waikato and Hawkes Bay respectively. This price included the cost of growing, harvesting, ensiling and feeding. Beef schedule prices were based on $1.80/kg live weight (LW). Feeding MS increased beef production in all scenarios tested by a mean of 36\% with values of 427, 581 and 576 kg net meat/ha/year for the no MS, S and W feeding systems respectively. Farm profitability (gross margin per hectare) was increased by feeding MS in W and S, with values of $934 and $754 respectively, compared with the no MS system of $636. MS feeding was still profitable at a schedule price of $1.40/kg LW and at higher MS costs up to 23 c/kg DM. Appropriate use of MS in beef production systems can substantially improve animal performance and farm profitability. }, issn = {1176-5283}, author = {Carracelas JG and Boom CJ and Litherland AJ and WMcG King and Williams ID} } @conference {42057, title = {Testing for quantitative trait loci for lactation persistency in dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {107-110}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {Lactational persistency has not been selected for in New Zealand dairy populations. Existing milk production data and pedigrees from New Zealand Holstein-Friesian cattle at pasture, recorded in the Livestock Improvement Corporation database were utilized with a grand-daughter design, for a genome-wide search for a quantitative trait locus for persistency of lactation. Persistency was defined as a weighted sum of test-day yields. A significant region was identified in one grandsire family on Chromosome 3 at microsatellite marker position AGLA247 (chromosomal position 67cM; P <0.05). To verify this result, data from a research dairy herd defining persistency as the mean of three weekly tests of daily yield in March (late lactation) divided by the equivalent daily yields in October (early lactation)) for three seasons beginning in 1997/98 were used in a phenotypic association study on Chromosome 3 only. One allele of marker HUJ246, close to the original region appeared to show an additive effect. The maximal difference between this genotype and the others at this marker locus was 12.3 {\textpm} 4.4\% of the mean persistency. The potential use of this marker in the New Zealand dairy cattle population depends on the current allele frequencies in the industry. }, issn = {1176-5283}, author = {Morris CA and Spelman RJ and Henderson HV and Cullen NG and Hyndman DL and Miller FM and Johnson DL and Molenaar AJ and Grigor MR and Davis SR} } @conference {41783, title = {Use of cDNA microarrays to investigate gene regulation in mastitis as a result of Escherichia coli infection in the bovine mammary gland}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {37-38}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {Bovine mastitis is the result of an inflammatory event in the mammary gland usually caused by a variety of bacteria in the udder and is one of the three major causes of disease in the Dairy industry world wide. The cost of mastitis in New Zealand is estimated at NZ$180 million for the industry and (DairyInsight, 2006).}, issn = {1176-5283}, author = {van Loenen-den-Breems NY and Molenaar AJ and Henderson HV and Seyfert H-M} } @conference {42042, title = {Variation in diet preference between sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {57-58}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {Herbivores show preferences for some dietary components over others (Cosgrove \& Edwards, 2007). The consequence of diet selection is that preferred components of the sward risk depletion and sustainability of sward composition is compromised. Species such as cattle that are less capable of discriminating between components of the sward (Grant et al., 1985) and maintain a higher intake on poorer quality swards (Collins \& Nicol, 1986) are useful in combating the more selective grazing behaviour of sheep. ...Continued }, issn = {1176-5283}, author = {Nicol AM and O{\textquoteright}Connor RP and Williams SJ and Bryan SJ} } @conference {41780, title = {A versatile sheep respiration chamber system for measurement of methane emission}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {29-30}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {Globally, the single most important source of greenhouse gas emissions from grazing systems is enteric methane (CH4) arising as a by-product of the fermentation of feed in the reticulo-rumen of ruminants (Clark et al., 2005). Methane is implicated in global warming and in countries where livestock constitutes a major emission source such as New Zealand, international commitments are driving research to develop emission reduction technologies, for which accurate measurements of CH4 emissions are ...Continued }, issn = {1176-5283}, author = {Pinares-Patino CS and Lovejoy P and Hunt C and Martin R and Molano G and Waghorn GC and Clark H} } @conference {41788, title = {Wool follicle characteristics in sheep with differing ventral wool length phenotypes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {49-52}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {Recent interest in sheep requiring less on-farm fleece management has lead to the development of sheep with long wool covering the trunk, but only short wool on the belly and breech. We have characterised developmental and structural features of the skin, including follicle density, primary to secondary follicle ratio and follicle activity state at various body sites of bare- and woolly-bellied ewes, and their foetuses. At 70 days of gestation, foetuses of bare-bellied ewes had developed fewer follicles than woolly-bellied sheep (1.7 {\textpm} 0.27 versus 2.8 {\textpm} 0.21 follicles per mm2; P<0.01). In adults, similar densities and ratios of primary to secondary follicles occurred in bare- and woolly-bellied ewes in each body site studied including dorsal, midside, anterior and posterior fleece positions, as well as the belly, breech and face. However, the proportion of inactive follicles in late autumn was greater in bare-belly adult ewes, not only on the belly (15.5 {\textpm} 1.9\% versus 4.9 {\textpm} 2.9\%; P<0.05), but also across the fleece which exhibited anterior-posterior and dorsal-ventral gradients in follicle activity. The short wool phenotype was thus associated with altered follicle cycles, but no differences in adult follicle densities. However, wool production might be compromised, as follicle activity varied across the whole fleece of bare-belly sheep. }, issn = {1176-5283}, author = {Craven AJ and Scobie DR and Ashby MG and Nixon AJ} } @conference {41764, title = {Breed and heterosis effects for milk protein composition estimated in two stages of lactation in New Zealand dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {399-402}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {The aim of this study was to estimate breed and heterosis effects for milk protein composition found within the two main breeds farmed in New Zealand, Holstein-Friesian (HF) and Jersey (J). Groups of 20 F, 20 J and 20 HFxJ crossbred cows (3 years and older) calved at pasture between July and September 2003 and were monitored throughout the 2003/04 season. Breed and heterosis effects were estimated for daily yields of milk, crude protein, true protein and casein and concentrations of crude protein, true protein, casein, α-casein, β-casein, κ-casein, α-lactalbumin and β-lactoglobulin, bovine serum albumin (BSA) and immunoglobulin G (IgG). Breed effects were significant (P<0.05) for all traits except for β-lactoglobulin, BSA and IgG. Compared to J cows, HF cows had significantly (P<0.05) higher daily yields of milk (+5.32 kg), crude protein (+0.13 kg), true protein (+0.11 kg) and casein (+0.10 kg) but significantly (P<0.05) lower concentrations of crude protein (-0.50 g/kg), true protein (-0.51 g/kg), casein (-0.45 g/kg), α-casein (-3.77 g/kg), β-casein (-2.08 g/kg), κ-casein (-1.74 g/kg) and α-lactalbumin (-0.14 g/kg). Estimates of heterosis effects for concentration of milk proteins were negative but only significant for κ-casein (-0.60 g/kg). These results show that that the individual protein fractions of milk are affected by breed but crossbreeding has no beneficial effect on milk protein composition.}, issn = {1176-5283}, author = {Back PJ and Lopez-Villalobos N} } @conference {41702, title = {Calcium balance in mid and late pregnancy and vaginal prolapse}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {61-67}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {Given the hypothesis that Ca status may be implicated in bearings, the purpose of the research in experiment 1 was to observe Ca status in old twinewes in normal commercial conditions to determine whether an association exists, and in the second experiment to manipulate Ca status to determine its effects on the incidence of bearings. In experiment 1, Romney ewes, scanned as twin (n=12) or single (n=12) pregnant, on each of 7 farms were identified and sampled at approximately 60, 30 and 7 d before the onset of flock lambing. Whole flock bearing incidence was recorded. Eleven to 41\% of pregnant ewes from different farms had marginal serum Ca and Mg concentrations at 60 and 30 d before onset of lambing. No relationship was found between serum minerals and metabolite concentration and bearing incidence among farms. The objective of experiment 2 was to reduce bearings on farms with high historical incidences of bearings by increasing Ca loss in urine in mid-pregnancy (60 to30 d pre-lambing) followed by increasing Ca supply in late-pregnancy (30 to 0 d pre-lambing). Five farmers fed 100 twin pregnant ewes 35 g of anionic salts in 300-500 g of supplemental pellets (DCAB -814 meq/kgDM) from 60 to 30 d before lambing. From 30 d these ewes were then injected with 4 ml of a long-acting vitamin D formulation (5 farms) while one farm also had an additional group supplemented with Ca (8g lime (ground calcium carbonate) /ewe) in an attempt to increase Ca availability. In addition, groups of ewes not treated withanionic salts were injected with vitamin D (2 farms) or supplemented with Ca (1 farm) from 30 d. Following consumption of anionic pellets in mid-pregnancy, the pH of the ewes{\textquoteright} urine was lower and urinary Ca:creatinine ratios were higher after 2 (6.73 vs. 7.32, P<0.002; 0.47 vs. 0.16, P<0.003) and 4 weeks (6.26 vs.7.23, P<0.001; 0.58 vs. 0.14, P<0.003) of treatment. However, neither the feeding of anionic salts in mid-pregnancy nor the Ca or vitamin D supplements in late-pregnancy consistently changed Ca serum concentrations or bearing incidence. }, issn = {1176-5283}, author = {Litherland AJ and Knight TW and Lambert MG and Cook TG and McDougal DBO and Day A} } @conference {41693, title = {Cattle breed evaluation at the US Meat Animal Research Centre and implications for commercial beef farmers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {9-17}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {Since 1969, 36 sire breeds have been evaluated for topcross performance in a series of experiments (Cycles) in the Germ Plasm Evaluation (GPE) Program. In Cycle VII, the 7 most prominent U.S. beef breeds (3 British breeds: Angus, Hereford, Red Angus; and 4 Continental European breeds: Simmental, Gelbvieh, Charolais, Limousin), comprising 83\% of U.S. breed association registrations, are being evaluated. In the 1970{\textquoteright}s, Continental breeds had greater growth rates and were heavier atweaning, yearling, and maturity. Today British breeds in the U.S. are comparable to Continental breeds for these traits. Steers of Continental sire breeds still excel in retail product yield (\%), but those of British sire breeds excel in marbling, an important component of U.S. carcass value, and enjoy a slight (P<.05) advantage in tenderness over Continental breeds. Since 1973, current expected progeny differences (EPD) from breed associations and GPE data have been used to estimate breed differences annually. Since 1993 adjustment factors have been calculated to be added to the EPD of 16 breeds to calculate across-breed EPD for growth traits. Multi-breed genetic evaluations are being explored by scientists at three U.S. Universities (Cornell, Georgia, Colorado State). In Cycle VII, DNA was obtained on all sires, dams, and progeny produced in the F1 cross generation, grand progeny, and great-grand progeny to provide for parentage determination, and for identification and validation of quantitative trait loci (QTL). Alternative mating plans are being explored to include additional breeds (> 15), to provide more efficient estimates of direct and maternal breed and heterosis effects, and to facilitate use of QTL in multi-breed genetic evaluations. Our review describes how the U.S. beef cattle breeding industry continues to use the evolving GPE results, and how the Cycle VII DNA samples will be used to provide progressively more accurate predictors of sire EPD on a within-breed or between-breed basis, through groups such as the National Beef Cattle Evaluation Consortium. The opportunities for U.S. cattle breeders arising from new breeding technologiesare described, including the potential for similar opportunities to be used in the New Zealand beef industry.}, issn = {1176-5283}, author = {Cundiff LV and Thallman RM and van Vleck LD and Bennett GL and Morris CA} } @conference {41729, title = {Choice of the most appropriate models and estimation procedures of lactation curves for grazing dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {209-214}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {The objective of this study was to determine the most appropriate lactation curve representation, a 4th order Legendre polynomial (LP) function or a mechanistic mammary gland (MG) model, for various lactation curve shapes of grazing cattle in New Zealand. The ability of two optimisation methods, evolutionary algorithm (EA) and the Newton method, used to find parameter values that minimised mean prediction error (MPE) was also determined. The 95\% confidence intervals for the parameters values and goodness of fitness for each lactation function and numerical algorithm were obtained with a bootstrapping strategy. Milk yields of three different cows were chosen to describe bi-peak, highly variable, and springpeak lactation curves. The MG function was able to find the best fit between predicted and actual values for the bi-peak and highly variable lactation curves withMPE of 2.7 to 3.7\%, compared with MPE of 6.5 to 11.9\% for the LP function applying Newton and EA. For the traditional lactation curve, the LP function applying Newton had the lowest MPE (1.7\%) with the MG function applying an EA the highest MPE (4.1\%). Overall, minimal differences in MPE were observed when solving using the Newton and EA. However, the Newton method fixed some parameters values of the MG function to achieve approximately the same MPE as the EA which manipulated all parameter values. The results of this study illustrate that a MG function solved with an EA is an accurate and efficient way to model non-standard lactation curves but a LP function in combination with the Newton method canbe better option for more standard lactation curves}, issn = {1176-5283}, author = {Bryant JR and Lopez-Villalobos N} } @conference {41694, title = {A comparison of carcass characteristics and meat quality for Angus, Hereford x Friesian, and Jersey x Friesian steers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {18-22}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {The aims of the two trials described here were to compare carcass characteristics and meat quality of Jersey-Friesian cross steers (Je x Fr) with Hereford-Friesian cross steers (He x Fr) and purebred Angus steers. Trial 1, which compared rising 3-year-old He x Fr with Je x Fr steers (20/grp), showed that the Je x Fr group had lighter carcass weights (93\%; P<0.001), yellower fat, slightly lower weight-adjusted dressing-out percentages (P<0.01), heavier weight-adjusted livers (P<0.01), and longer carcasses at the same weight (P<0.001). In Trial 2, 27-month Je x Fr steers (n=15) were compared with He x Fr (n=15) and Angus steers (n=14). Differences similar to those for Trial 1 were shown, and in addition the Je x Fr steers had lower fat depths and a lower yield of several cuts from the round.For both trials the Je x Fr group had a more mature pattern of incisor teeth eruption. For Trial 2 the quality of meat from the longissimus muscle did not differ between groups for ultimate pH, intramuscular fat level, colour, Warner-Bratzler shear force, or waterholding capacity. Sensory analysis by a trained panel revealed no differences in tenderness, flavour, or juiciness, in contrast to some other reports where beef from Jersey or Jersey-cross cattle has been favoured. These results indicate that the Je x Fr steers in these trials offered no advantages relative to He x Fr or Angus cattle, but they did show some minor disadvantages. These results, however, need to be considered alongside other reports indicating that Jersey or Jersey-cross steers will sometimes yield beef with advantages in levels of marbling fat and palatability.}, issn = {1176-5283}, author = {Purchas RW and Morris ST} } @conference {41986, title = {Comparison of suckling frequency of red and F1 wapiti-red calves reared on red hinds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {237-241}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {In New Zealand venison production systems crossbreeding red hinds with wapiti stags is very common. The resultant wapiti-red crossbred offspring is a larger, fastergrowing animal than its red counterpart. How do these crossbred progeny grow faster on a red hind? We hypothesised that the crossbred progeny would have increased milk intakes, which would be reflected in increased suckling of their red hind dams. A pasture based lactation experiment was conducted over the {\textquoteright}natural{\textquoteright} (non-weaned) suckling period (birth Nov/Dec. to Sep.) with F1 wapiti-red crossbred single and twin calves (n=11) naturally reared by red hinds (n=9), and red calves (n=8) naturally reared by red hinds (n=8). Suckling behaviour was observed at least one day per month between dawn and dusk. Suckling bout frequency, duration and time of day were recorded for all calves and any allosuckling was also noted. We found no significant differences (p >0.05) in suckling bout time, frequency or total time spent suckling between red or wapiti crossbred offspring. The only confirmed allosuckling was between individuals from different sets of twins. The F1 wapiti-red crossbred offspring were 30\% heavier, with growth rates up to 39\% greater than their red cohorts. These results have interesting implications for the red hind crossbred calf venison production system; do the wapitired crossbred calves consume more milk? If so how do they influence the hind{\textquoteright}s milk production? Do they consume more pasture and/or substitute it for milk? Better understanding of these factors should help increase calf growth rates during lactation.}, issn = {1176-5283}, author = {Ward JF and Archer JA and O{\textquoteright}Neill KT and Littlejohn RP} } @conference {41742, title = {Comparison of the effect of simultaneous grazing of sheep or cattle with hinds during fawning}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {280-284}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {Groups (4) of aged, pregnant red deer hinds (n = 7 or 12) were set-stocked pre-fawning with similar liveweight per ha of either dry ewes or yearling heifers in one of two paddocks equally divided in area (2 replicates). Cattle and sheep were progressively withdrawn from each area independently so that the average pasture height did not fall below 6 cm. The liveweight of the hinds and fawns was recorded and pasture samples taken for botanical and chemical analysis. There was no significant effect of sheep vs. cattle on the liveweight change of hinds or their fawns. All groups of hinds lost condition over lactation even though pasture height was maintained around 6-8 cm. However the liveweight gain of the fawns (from mid January to early March) was close to 350 g/day. Overall, there was no significant difference in composition or quality between the pastures grazed by the two stock combinations. We conclude from this study that under the conditions of this trial, in which the pasture was kept under tight control (6-8 cm) over the whole of lactation, there was no difference in the effect of the co-grazing species (sheep or cattle) on the performance of lactating hinds and their fawns.}, issn = {1176-5283}, author = {Nicol AM and Edwards GR and Ridgway MJ and Griffiths WM} } @conference {41769, title = {Comparison of white clover , perennial ryegrass and the high tannin containing forage Lotus pedunculatus as finishing diets : Effect on sheepmeat quality}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {426-430}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {Rams were finished for 22 days on Lotus pedunculatus(LP), perennial ryegrass (Lolium perenne) (RG), or white clover (Trifolium repens) (WC). WC sheep had higher carcass weight (P < 0.001), muscle fat (P < 0.01) and back fat (P < 0.03) depths compared to those finished on LP or RG. Muscle glycogen at slaughter was lower (P < 0.01) in RG compared to LP and WC. Loin p-Cresol was higher (P < 0.001) in LP animals compared to WC or RG. Meat from RG tended to havea more stable retail colour display life compared to LP or WC (P < 0.01). Meat from LP had higher loss of weight during cooking (P < 0.05) compared to WC. The animal diet did not affect the flavour of their meat. There was a strong negative correlation between loin p-Cresol and sheepy odour (r = -0.7; P < 0.05). Within the parameters of this study, finishing lambs on a high tannin containing forage diet did not improve the quality attributes of their meat. The digestibility of the forage diet seems to have exerted a stronger effect on meat quality.}, issn = {1176-5283}, author = {Farouk MM and Tavendale M and Lane G and Pulford D and Waller J} } @conference {42002, title = {Concentrations of pesticides in fleeces after pour-on and saturation dipping of Merino sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {320-325}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {A year-long farm trial was performed in 2003/04 to determine the relative efficacies of commercial formulations of diflubenzuron and triflumuron lousicides and measure pesticide concentrations in different parts of the fleece throughout the year. Significant differences were found between the concentrations of pesticides present on samples of fleeces taken from the back and side initially (P<0.05), 5 months (P<0.001), and 12 months (P<0.05) after pour-on treatments. The bulk of the pesticides from pour-on treatments remained in the zone where they had been applied and little moved to the sides of the sheep. Five months after application pesticide concentrations were significantly higher (P<0.001) in staple tip compared with butt samples on both back and side fleece samples for pour-on or jetting treatments, confirming recent predictions that diffusion of pesticides in greasy wool will be limited. Concentrations in butt samples from 5 months onwards were near or less than the mean LD95 doses reported for diflubenzuron for susceptible {\textendash} 0.31 mg/kg, 95\% confidence limits (CL) 0.16-1.25 mg/kg {\textendash} and resistant lice populations {\textendash} 4.4 mg/kg, 95\% CL 1.4-71 mg/kg. The results offer a possible explanation for the anecdotal reports of poor efficacy of some pour-on louse treatments and treatment failures on farm.}, issn = {1176-5283}, author = {Rankin DA and Reid TC and Cole DJW and Urquhart RA and Syhre MS} } @conference {42003, title = {Culture of ovine keratinocytes : An experimental model for wool growth}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {326-331}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {Wool fibres are formed from the germinative epithelium, a population of keratinocytes at the base of wool follicles. In order to test the function of candidatewool growth genes and pharmaceuticals, we have developed methods to isolate and maintain these cells inculture. Pure, clonal lines of ovine keratinocytes were isolated from both vibrissae and wool follicles. Vibrissa-derived cells proliferated more extensively before senescing, but cells from both follicle types possessed ample proliferative potential for further experimentation. Standard assays have been established to quantify keratinocyte proliferation and apoptosis in culture. Differentiation of keratinocytes could be induced by maintaining them at high density for a week. Keratinocytes expressed differentiation markers for epidermis and inner root sheath. Expression of a chosen gene could be up-regulated by transfection with a liposome-borne plasmid. A transfected plasmid encoding a fluorescent reporter protein was expressed in 68-100\% of cells. Similarly, expression of a gene of interest could be suppressed by RNA interference. The experimental tractability of these keratinocytes suggests that they will be a valuable model for investigating the cell biology and molecular genetics of wool growth. The methods described form a unique experimental system to identify leads for new technologies that improve wool production.}, issn = {1176-5283}, author = {Rufaut NW and Goldthorpe NT and Craven AJ and Wallace OAM and Wildermoth JE and Pedersen G and Nixon AJ} } @conference {41717, title = {Current status and future of genomic selection}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {147}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {DNA marker test usage is expanding rapidly in the New Zealand livestockindustry. Uptake is already reaching in excess of 30\% of animals in the sire breeding tier for some industries. However, what is confusing to many commercial farmers and advisors is the diversity of claims and uses of these tests and the jargon that surrounds the topic. The aims of the associated Landcorp Speaker presentation and this contract, are to clarify just what DNA markers can do, what work is currently being undertaken, what tests are currently available, and what implications these have for farming systems in New Zealand over the next decade.}, issn = {1176-5283}, author = {McEwan JC} } @conference {41719, title = {Current status of QTL and association studies in New Zealand cattle , sheep and deer}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {153-159}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {In the last 15 years, a series of experiments has beencarried out to search for quantitative trait loci (QTL) in New Zealand cattle, sheepand deer. A QTL represents the position on a chromosome where there is a statistically significant genetic effecton a measured trait. This paper reviews data published so far from these QTL trials and from various association studies. Although the measurement of traits (or {\textquoteleft}phenotypes{\textquoteright}) and the sampling of tissue or fluid for DNA may be complete, the genotyping of DNA isstill incomplete in most studies; further work may be expected as new DNA genotyping techniques and new genomic data become available, and as funds allow. In cattle, we describe the current status of research for carcass composition, meat quality, pubertal traits, milk yield and milk composition traits, and resistance to facial eczema and bloat. In sheep, we include QTL searches for disease traits (resistance to nematode parasites, facial eczema, ryegrass staggers, and footrot), muscling and carcass composition, reproductive traits, wool traits, and lamb survival. In deer, QTL searches have been carried out for live weights, seasonality and pubertal traits, using measurements from an interspecific hybrid. Generally, significant results have been followed further by finemapping and independent validation, before release to industry. Some of the mapping techniques will be described, with examples. So far, QTLs under study in New Zealand have led to the identification and use of gene-tests or marker-tests for meat tenderness and carcass composition in beef cattle, milk yield and composition traits in dairy cattle, and meat yield \%, muscling and litter size genes in sheep.}, issn = {1176-5283}, author = {Morris CA and Campbell AW and Cullen NG and Davis GH and Everett-Hincks JM and Hall RJ and Henry HM and PL Johnson and McEwan JC and Phua SH and Wilson T} } @conference {41704, title = {The deer industry{\textquoteright}s productivity strategy : A five-year vision}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {73-77}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {Advances in deer farming productivity have been muted in relation to other livestock industries but the potential for dramatic improvement clearly exists. Anindustry working group has developed a productivity strategy closely aligned with the venison industry strategy that emphasises extending the four-month consumption demand of the traditional game seasonto a 12-month chilled supply of high-value retail product. Underpinning this, the productivity strategy targets two basic outcomes; more calves conceived, born earlier and surviving to sale, and heavier prime animals supplied earlier in the season. Productivity targets include a 2\% annual increase in survival to sale over the next five years and a 2.5\% annual individual growth rate increase. Emphasis is on capturing genotype advantages in growth and seasonality, and determining aspects of seasonal nutrition and the potential of new forage cultivars to add to this potential for growth. Productivity success must be measured in economic indices (carcase returns per hectare, cost of production per kilogram of dry matter consumed and per hectare economic performance) and the planned timing of carcase harvest against a variable seasonal schedule. Productivity improvements are best illustrated in clear practical situations providedby focus farms to inspire technology uplift and practical feedback from farmers and researchers. }, issn = {1176-5283}, author = {Pearse AJ and Fung L} } @conference {41970, title = {Developing genomic resources for whole genome selection}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {148-153}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {After more than 20 years of research, genomic technology is now on the cusp of widespread adoption in animal industries. Industry adoption will initially involve improvement of existing breeding and traceability systems. DNA variants, commonly called markers, used in these systems can provide 4 pieces of information: identity, parentage, prediction of an animals genetic worth and its individual performance. The usability of the technology and its adoption is increasing as genotyping prices decline. The major challenges are: to decrease sample collection, processing and reporting costs, and integrate the systems so that all 4 separate pieces of information can be obtained from a single test. Underpinning future research will be availability of sequenced genomes for each of the production species, and large scale {\textquotedblleft}SNP chips{\textquotedblright} derived from them. Currently, the technology provides the ability to identify and map and use variants affecting animal performance in commercial populations. These technologies use existing natural genetic variation already present in the population. The potential of these technologies is safer and more nutritious food produced with less environmental impact and greater animal welfare due to lower level of disease.}, issn = {1176-5283}, author = {McEwan JC} } @conference {41958, title = {Development of large scale commercial AI for genetic improvement in farmed red deer in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {82-90}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {Experienced bovine AB technicians can be readily trained to successfully perform trans-cervical AI in red deer. Stags of all ages, including yearling spikers, can produce semen of acceptable quality and quantity at regular intervals from as early as February until mid-winter. Pregnancies rates to a single fixed-time insemination are typically 60-75\% with unknown herd factors contributing much of the variation. Yearling hinds are capable of acceptable pregnancy rates when inseminated in late February, at least a month earlier than is current practice. Within broad limits, considerable flexibility appears to exist when hinds are inseminated relative to the end of synchrony treatment.A deer-specific intra-vaginal progesterone-releasing device has been shown to provide higher terminal levelsof circulating progesterone compared with existing devices. Current field trials will determine its affect onpregnancy rates. We conclude that the genetic and reproductive technologies for increasing weight-for-age in deer have been successfully integrated and applied to commercial red deer in New Zealand.}, issn = {1176-5283}, author = {McMillan WH and Asher GW} } @conference {41768, title = {Does high-frequency immobilisation of sheep post-mortem affect meat quality ?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {420-425}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {This study evaluated the impact of a newly developed high frequency immobilisation unit on meat quality traits of lamb carcases. This was achieved by examining pH and temperature profiles, objective meat colour (L*, a*, b*, ratio values 630 nm/580 nm and chroma), shear force, cooking loss and sarcomere length. In total 80 lambs from 3 different consignments were assessed. The animals were killed over two days and of the 40 killed on each kill day, 20 were exposed to the immobiliser and 20 were not. The results showed that the high frequency immobiliser unit had no effect on sarcomere length and pH except when pH was predicted at 25{\textdegree}C. There was also no effect on shear force and cooking loss percentage, but there were some minimal differences for some meat colour traits. These differences were shown in the final GM (rump) measurements only (7 day aged), where cuts from immobilised carcases had a lower L* values and higher a*, b* and chroma values. Overall the results showed that there were minimal effects of the immobilisation treatment which confirms previous anecdotal evidence. The high frequency immobilisation unit has benefits in that it enables abattoir workers to begin processing the carcases safely within approximately 30 seconds of death with no apparent negative effect on meat quality traits. It also means that other electrical inputs can be used to manipulate pH fall, without immobilisation affecting pH.}, issn = {1176-5283}, author = {Toohey ES and Hopkins DL} } @conference {41983, title = {A dynamic model incorporating dietary protein for predicting liveweight gain of parasitised grazing lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {220-225}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {Internal parasites are one of the major constraints toliveweight gain (LWG) in young grazing ruminants. However, even in parasite-free animals, diets low in crude protein can constrain LWG from values expected on the basis of metabolisable energy intake alone. We investigate the impact of protein supplementation in overcoming reduced growth rates of parasitised animals. This was done via a dynamic model which assumes increased maintenance requirements (immune requirements, increased cell turnover and mucous production) in parasitised animals. A key output from the model is LWG over an extended grazing period. We calibrated and validated the model using published data from an indoor feeding experiment in which trickle-infected lambs were fed for 20 weeks on three diets providing different amounts of metabolisable protein. The mean liveweight and worm burden predicted from the model compared well with experimental data. Such models will prove useful in designing supplementation strategies for grazing lambs where anthelmintic control of parasites is not a management option.}, issn = {1176-5283}, author = {Louie K and Burggraaf VT and Pacheco D} } @conference {41993, title = {Effect of age on methane emissions of red deer stags from weaning until one year of age grazing perennial ryegrass-based pasture : Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {276-279}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {The emission of greenhouse gases is a current global issue as global warming and climate change appear a reality. The Kyoto Protocol is an international agreement, which New Zealand (NZ) has signed and under obligations of the agreement, New Zealand must reduce its greenhouse gases (GHG) to the emission levels of the baseline year (1990), by the first ratification of the Protocol in 2008. Methane emissions from ruminant livestock in NZ represent 31.3\% of New Zealand{\textquoteright}s total greenhouse gas emissions; therefore accurate inventories of methane production for all farmed livestock classes are required.}, issn = {1176-5283}, author = {Swainson NM and Hoskin SO and Clark H and Lopez-Villalobos N} } @conference {41724, title = {Effect of divergent selection for wool bulk on live weight and wool characteristics in Perendale sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {180-186}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {A sixteen year selection trial in a flock of Perendale sheep selected for either increased (H line) or decreased (L line) wool bulk at yearling (hogget) shearing, was undertaken at Whatawhata, and later Winchmore Research Stations. A total of 2,620 progeny sired by 172 rams joined in single sire matings were measured, with data from an additional 664 fleeces providing direct information on base flock characteristics. A restricted maximum likelihood (REML) animal model adjusting for fixed effects of year, sex, birth date and birth/weaning rank was fitted to the data. Heritability estimates {\textpm} standard errors for each of the measured characteristics were; core wool bulk (0.57 {\textpm} 0.03), pre-shear live weight (0.35 {\textpm} 0.04), greasy fleece weight (0.44 {\textpm} 0.04), washing yield (0.42 {\textpm} 0.03), clean fleece weight (0.45 {\textpm} 0.03), staple length (0.54 {\textpm} 0.03), total crimps (0.38 {\textpm} 0.03), crimp frequency (0.46 {\textpm} 0.03), mean fibre diameter (0.62 {\textpm} 0.04), fibre diameter variation (0.58 {\textpm} 0.04) and mean fibre curvature (0.67 {\textpm} 0.04). At the end of the trial, line divergence (H {\textendash} L) in core wool bulk and fibre curvature amounted to 2.5 phenotypic standard deviation units. It was associated with a positive divergence in crimp frequency and a negative divergence in staple length, washing yield and clean fleece weight of +2.1, -1.7, -1.4 and {\textendash}0.8 standard deviation units respectively, and lesser changes in other traits.}, issn = {1176-5283}, author = {Sumner RMW and Clarke JN and Cullen NG} } @conference {41700, title = {The effect of Finnish Landrace and Texel ewe and lamb behaviour after tagging on lamb survival to weaning}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {48-54}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {The study was carried out on a commercial New Zealand sheep farm with performance recorded straightbred Finnish Landrace and Texel primiparous ewes. The objective of the study was to determine the strength of ewe-lamb attachment at tagging by investigating the behaviour of Finn and Texel ewes and their lambs and relate those behaviours to survival to weaning. Lamb and ewe behaviour was observed for ten minutes after the lambs were ear tagged. Finn ewes took at least twice as long to contact their lambs than Texel ewes (P<0.01). There were no breed differences for time of lamb to stand and suck after tagging. Finn twin lambs took longer to follow their dam than Texel twin lambs (P<0.01). Ewes with higher Maternal Behaviour Score (high MBS favourable) contact their lambs quicker and the lamb stood, sucked and followed its moving dam more quickly than lambs of ewes with low MBS (P<0.05). Texel ewes with twins had higher low-pitch bleating frequencies than Texel ewes with a single lamb (P<0.01). MBS had a significant and positive effect on low-pitch bleating frequency (β=19.3 {\textpm} 3.51 bleats/MBS, P<0.0001). Ewes with lower MBS at tagging high-pitch bleated significantly more if their lamb took longer to stand (β=5.25 {\textpm} 0.65 bleats/minute, P<0.0001). Lamb survival improved3-fold for lambs that sucked their dam (P<0.01) and improved nearly 5-fold for lambs that stand, within ten minutes after tagging (P<0.05). Lamb behaviour at tagging better explained the variation in lamb survival than the ewe behaviours analysed. }, issn = {1176-5283}, author = {Everett-Hincks JM and Blair HT and Stafford KJ and Lopez-Villalobos N} } @conference {41744, title = {Effect of increased somatic cell count on lactation yields of milk , fat and protein}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {293-296}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {The purpose of this study was to estimate the effect of increased SCC on production in New Zealand dairy farms. Herd test data from lactations one through six were used in the study. Herd test milk, fat and protein yields were modelled as a function of days in milk at the time of the herd test and the logarithm (base 2) of SCC. The model estimates were used to obtain the predicted value for each observation using the actual log SCC and again where the log SCC was increased by one (i.e. doubling the SCC level). For first-lactation cows, the reduction in a 270-day lactation yield from a doubling of the SCC was estimated to be 78 litres, 2.39 kilograms and 2.04 kilograms for milk, fat and protein yield, respectively. Herd SCC level also influenced the extent to which a doubling of SCC decreased production. For first-lactation cows every doubling of SCC was predicted to result in an average loss of 67 and 90 litres in the lowest and highest quartiles, respectively.}, issn = {1176-5283}, author = {Winkelman AM and Montgomerie WA and Johnson DL} } @conference {41740, title = {The effect of live yeast inclusion into mixed forage diets on milk yield , locomotion score , lameness and sole bruising in first lactation Holstein Friesian dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {272-275}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {The aim was to assess the effect of supplementing mixed forage diets with live yeast on milk yield, locomotion score, lameness and sole bruising in first lactation Holstein Friesian dairy cattle. Heifers (n 34) were divided into two groups according to calving date, breeding value (milk fat and protein yield), live weight, body condition and post-partummilk yield and offered a mixed forage diet of grass, maize and whole crop silage, 17 were offered the mixed diet withthe addition of live yeast (Y), 17 were offered the same mixed forage diet with no additional live yeast (NY). All animals were assessed weekly for milk yield and composition, locomotion score up until 160 days in milk (DIM). Mean milk yield (Y: 29.5, NY: 27.1) and milk solids (Y: 1.98, NY: 1.80 (kg/h/d) were significantly higher with the addition of yeast (P<0.001). Sole lesion score increased significantly at day 160 (50 DIM: 1241 b, 100 DIM: 1295 b, 150 DIM: 1676 a) and of the WL at day 100 pp (50 DIM: 1042 b, 100 DIM: 1448 a, 150 DIM: 1710 a) (P<0.001). The hind outer (HO) claws had significantly higher lesion scoresthan inner claws (sole outer: 340.2, others 149.4 to 184.2; White line Outer: 267.5, others: 168.4 to 228.9) (P<0.001). Heifers offered forage diets with the addition of yeast had significantly lower sole (Y: 1151.5 b, NY: 1645.3 a)(P<0.05) and WL lesions at 160 DIM. The addition of live yeast increased milk yield and reduced lesion and locomotion score in first lactation heifers.}, issn = {1176-5283}, author = {Lethbridge LA and Margerison JK and Parfitt D} } @conference {41711, title = {The effect of maternal liveweight gain of 15-month-old beef heifers on foetal weight}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {117-120}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {Dystocia in 2-year-old beef heifers is a major factor limiting the willingness of farmers to breed 15-month-old heifers in New Zealand. Foetal oversize relative to the size of the heifer is a contributor to dystocia. This study aimed to determine the effect on foetal weight of maternal liveweight change during joining and early pregnancy. Sixteen 15-month-old Angus heifers were allocated to moderate (444 {\textpm} 30 g/day) or low (109 {\textpm} 28 g/day) liveweight-gain treatments for 21 days prior to and 91 days after insemination. Gravid uteri were recovered on day 91 of pregnancy. Foetuses from the low-fed heifers tended to be heavier than foetuses from the moderate-fed heifers (215.6 {\textpm} 6.7 g and 198.4 {\textpm} 6.8 g, respectively; P=0.09). Foetal weight per 100 kg maternal weight was greater (P<0.01) in foetuses from the low treatment (58.9 {\textpm} 2.5 g/100 kg) than in foetuses from the moderate treatment (47.4 {\textpm} 2.6 g/100 kg). Weight of foetal membranes was greater (P<0.05) in the low treatment (262 {\textpm} 16 g) than the moderate treatment (213 {\textpm} 16 g). Foetal weight was correlated with cotyledon weight (r=0.59; P<0.05). Moderate compared with low maternal liveweight gain reduced foetal weight relative to maternal live weight.}, issn = {1176-5283}, author = {Hickson RE and Lopez-Villalobos N and Kenyon PR and Morris ST} } @conference {42019, title = {Effects of dietary herb supplements on sheepmeat flavour}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {413-419}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {Sheepmeat flavour is characterised by distinctive species derived odours and flavour notes derived from the diet termed as {\textquoteleft}pastoral{\textquoteright} for pasture-based farming systems. An exploratory investigation was undertaken to determine if the flavour attributesof sheepmeat could be altered by short-term dosing of sheep with fresh or concentrated herbs. Twelve animals were dosed with 9 different fresh and/or concentrated herbs over 3 days. The animals were slaughtered, sub-sampled, and chemical analyses of levels of flavour compounds in the subcutaneous fat were performed along with sensory evaluation of the meat samples by a trained panel. From the sensory evaluation of the meat samples, the two animals that received the garlic powder supplement were described by the panellists as {\textquoteleft}garlic{\textquoteright},and these samples were significantly less intense in {\textquoteleft}sheepmeat{\textquoteright} (P=0.001) and {\textquoteleft}sweet{\textquoteright} (P=0.007) flavours and also had increased {\textquoteleft}barnyard{\textquoteright} (P=0.011) and {\textquoteleft}foreign{\textquoteright} (P<0.001) flavours. Subcutaneous fat skatole and indole levels for these animals were found to be significantly higher (P<0.001) compared to those grazingryegrass. Other treatments were not significantly different in sensory evaluation. A garlic powder dose response trial was then carried out with 5 sheep receiving between 0 and 200 g/day of powder for two days. After slaughter, subcutaneous fat skatole levels were found to be elevated for animals receiving >50 g/day garlic powder. The results indicate that dosing sheep with garlic powder has a detrimental effect on the animal{\textquoteright}s ability to detoxify and remove skatole from the circulatory system, with consequent detrimental effects on the overall sensory quality of the meat. Thus a herbal dietary supplement to either mask undesirable flavours of sheep meat, or impart desirable flavours, is yet to be discovered.}, issn = {1176-5283}, author = {Fraser K and Lane GA and Kirk MR and Keogh RG and Cummings TL} } @conference {41965, title = {The effects of ewe size and nutrition during pregnancy on growth and onset of puberty in female progeny}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {126-129}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {In 2005, {\textquoteleft}heavy{\textquoteright} and {\textquoteleft}light{\textquoteright} Romney ewes were selected, synchronized and artificially inseminated. Half of the ewes in each weight group were fed ad libitumand the other half were restricted to maintenance from days 21-140 of pregnancy, resulting in fourgroups: {\textquoteleft}heavy{\textquoteright}-maintenance (HM), {\textquoteleft}heavy{\textquoteright}-ad libitum(HA), {\textquoteleft}light{\textquoteright}-maintenance (LM) and {\textquoteleft}light{\textquoteright}-ad libitum(LA). The aim of the present study was to investigate the effects of ewe size and nutrition during pregnancy on growth and onset of puberty in female progeny. Lamb birth weights were recorded. After weaning, the progeny were managed as one flock and weighed monthly. Crayon-harnessed teaser rams were joined with the lambs to investigate the onset of puberty. Maternal nutrition during pregnancy affected live weight of lambs from 22 days of age till weaning (100 days of age) (P<0.05). During the first 22 days of life, the growth rate of lambs born to LM was lower (P<0.05) compared with the other groups (215 {\textpm} 8.2, 261 {\textpm} 8.0, 250 {\textpm} 7.9, 275 {\textpm} 7.3 grams/day, for lambs born to LM, LA, HM and HA ewes respectively). From weaning until one year of age lambs born to LM dams were lighter than lambs born to HM dams (P<0.05). No differences in the age of onset of puberty were found among the four groups. Singletons reached puberty earlier than twins (P<0.01). At 13 months of age, no long-term effect of maternal nutrition on the live weight of resulting ewe offspring was found, although dam size had a significant effect on live weight and growth rate. However, neither dam nutrition nor size had any effect on the age of onset of puberty.}, issn = {1176-5283}, author = {van der Linden DS and Kenyon PR and Jenkinson CMC and Peterson SW and Lopez-Villalobos N and Blair HT} } @conference {41746, title = {Effects of experimentally induced and treated Streptococcus uberis mastitis early in the dry period on production in the subsequent lactation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {303-306}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {The effect of experimentally induced clinical mastitis in the early dry period (EDPCM) upon the milk production in the subsequent lactation was examined. Animals with low somatic cell counts at herd test (n=165) were experimentally exposed to Streptococcus uberis in their early dry period in an efficacy study of two external teat sealants. Animals that developed EDPCM after challenge (n=127) were treated with an antibiotic after observation of clinical mastitis. Total lactation yields of milk, fat, protein and milk solids were analysed with respect to treatment group (fixed effect) and the covariables: calving week (linear), parity (linear and quadratic) and proportion of Holstein-Friesian genes (linear). For animals that suffered EDPCM and those that did not, there was no difference in production (milk yield; 5126 vs. 5010 litres, fat yield; 267 vs. 264 kg, protein yield; 182 vs. 179 kg). It was concluded that promptly treated EDPCM due to S uberis, did not affect production in the subsequent lactation.}, issn = {1176-5283}, author = {Petrovski KR and Williamson NB and Fernandez C and Grinberg A and Lopez-Villalobos N and Parkinson TJ} } @conference {41955, title = {The effects of zeranol or zinc supplementation before lambing on the incidence of vaginal prolapse in twinning ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {68-72}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {The objectives were to determine whether Zeranol (ZER) and its metabolites or pharmacological zinc levels could change the incidence of vaginal prolapse(bearings) in ewes. In the ZER experiment 100 twin pregnant ewes were controls, a further 50 ewes each received either two low (24 mg and then 12 mg) or two high (36 mg and then 24 mg) doses of zeranol (ZER) implants separated by a four-week interval with 65\% of treated ewes receiving an additional 12 mg implant at set stocking. Urine samples were collected from 12 ewes, twice weekly, bulked into three samples and analysed for Zearalenone (ZEN), ZER and creatinine. Two weeks after receiving an implant, the ZER:creatinine ratio increased from 2.6 in C ewes to 21, 30 and 36 and the ZEN ratio from 3.25 to 6.7, 10.8 and 14.7 following treatment with 12, 24 and 36 mg of ZER (P<0.01). One month after treatment the ZER and ZEN ratios had decreased but were still higher in treated than control ewes (ZER 3.6 vs.11, P<0.01; ZEN 1.2 vs.5.2, P<0.01). The bearing incidence was 3\%, 2\% and 2\% for control, low and high dose ZER respectively. In the second experiment 100 scanned twin or triplet pregnant ewes were administered with 72 g of zinc oxide (The Time Capsule {\textregistered}) as a ruminal bolus 4-6 weeks before lambing on four farms with historical high incidences of bearings. Pre-treatment and all control serum zinc concentrations were low (9.4 {\textpm}0.2 mmol/L) but not considered deficient. Zinc supplementation increased serum zinc concentrations to 21.5 mmol/L (P<0.001). Bearing incidence was higher (P<0.001) in zinc-treated (4\%) than in control ewes (1.9\%). In conclusion, bearings are not caused by ingestion of ZEN in late pregnancy. The role of zinc in bearings warrants further study.}, issn = {1176-5283}, author = {Litherland AJ and Knight TW and McDougall DBO and Cook TG and Sprosen J and Lambert MG} } @conference {41723, title = {Estimation of autumn live weight breeding values in progeny test datasets when progeny are slaughtered to achieve a target carcass weight}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {175-179}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {An analysis was undertaken to investigate how lamb autumn live weight breeding values could be calculated from fixed carcass weight progeny tests (e.g. lambs slaughtered at monthly intervals at a threshold carcass weight). Analysis of growth rate is problematic for this progeny test design as the slaughter groups may experience vastly different environmental conditions, both within and between years. Variance components were estimated from an animal model using restricted maximum likelihood (REML) on data from 11,411 Coopworth progeny records and 126 Coopworth sires. The dataset contained records of weaning weight and live weight at four, five and six months of age (LW4, LW5 and LW6, respectively) collected from 1995 to 2004 in a flock run at Woodlands Research Station. The multivariate mixed linear model included lamb birth day deviation as a covariate, sex of lamb, birth rearing rank, age of dam and live weight contemporary group as fixed effects, and sire as a random effect. The WWT model also had dam fitted as a random effect to give WWT direct and maternal effects (WWTdand WWTm). The analysis was then repeated, but with animals records removed from the dataset once they achieved a threshold weight of 31 and 27kg for ram and ewe lambs, respectively, on data prior to or following linear scaling by contemporary group mean. The heritabilities estimated from the full dataset for WWTd, WWTm, LW4, LW5 and LW6 were 0.30{\textpm}0.03, 0.04{\textpm}0.01, 0.49{\textpm}0.02, 0.49{\textpm}0.02 and 0.51{\textpm}0.02, respectively. These traits were highly correlated with both phenotypic and genetic correlations between the direct traits ranging from 84 to 99\%. The same analysis on the two culled datasets resulted in only minor changes the variance components. The correlation between sire breeding values for autumn live weight (LW6) estimated from the full and the two culled datasets were 98.8\% for both models. Autumn live weightbreeding values can be accurately estimated from datasets which include progressive culling if a multivariate live weight analysis is undertaken, and data from all animals measured at each date are used.}, issn = {1176-5283}, author = {Jopson NB and McEwan JC and Knowler KJ and Wheeler R} } @conference {41738, title = {Evaluation of a model that estimates insulin sensitivity in dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {261-265}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {Glucose challenge data was used to model parametersdescribing the dynamics of the glucose-insulin system such as glucose effectiveness (SG), acute insulin response to glucose (AIRg) and insulin sensitivity (SI) in dairy cows. The relationship of these parameterswith post-partum anovulatory interval (PPAI) was also determined. Twenty-five HF cows of New Zealand (NZ; n=13) and Overseas (OS; n=12) origin, were fed either pasture (n=12) or a total mixed ration (TMR; n=13) in a 2x2 factorial design. At two weeks postpartum, they were challenged intravenously with 300 mg of glucose/kg live weight. There was no effect of diet on SG(P=0.302), SI(P=0.17) or AIRg(P=0.093) despite TMR cows of both genotypes having higher values. There was no effect of genotype on SG(P=0.234), SI(P=0.742) or AIRg(P=0.385). Correlations of these parameters with PPAI were not statistically significant: SI (r 2=0.087, P=0.310), SG(r 2 = 0.001, P=0.962) and AIRg(r 2 =0.036, P=0.320). Use of this model demonstrated that insulin response parameters were not closely associated with PPAI.}, issn = {1176-5283}, author = {Back PJ and Boston RC and Palliser CC and Kolver ES and Chagas LM} } @conference {41759, title = {Evaluation of a practical weaning weight index for extensively-grazed beef cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {370-376}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {Little objective culling is practiced in many commercial beef herds in New Zealand possibly due to the absence of a performance recording system that is able to accurately predict the calf rearing ability of cows when calving date is unknown. Data of 1,306 calves from four different herds including birth, marking and weaning weights and dates was used to construct an Extensively Grazed Weaning Index (ECWIndex) to rank cows on their calf rearing ability without the use ofcalving date. Three indicator traits, marking weight, weaning weight and average daily gain (ADG) between marking and weaning (all adjusted for sex of calf and age of dam but not for age of calf) were used in the index as they were the most favourably correlated with 200 day weight of the readily measurable calf traits considered. A number ofeasily obtainable herd variables were used to calculate index weights for the indicator traits. When the model was applied to data from two additional herds the cow ranking based on the index was very similar to that based on 200 d weight (r = 0.95 and 0.92 and R2=91.2\% and 85.4\%). The use of the model will provide commercial herd managers an objective method for culling cows and selecting replacement heifers and may eventually allow the use of data from commercial herds in the calculation of breeding values of stud bulls.}, issn = {1176-5283}, author = {Thomas CW and Bywater AC and Miller SP} } @conference {41770, title = {Evaluation of the sulphur hexafluoride tracer technique for methane emission measurement in forage-fed sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {431-435}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {The aim of this study was to evaluate the sulphur hexafluoride (SF6) tracer technique for methane (CH4) emission measurement in sheep. Methane emissions from ten Romney sheep were individually measured both by the SF6tracer ({\textquoteleft}tracer CH4{\textquoteright}) and by the indirect calorimetry chamber ({\textquoteleft}calorimetric CH4{\textquoteright}) techniques while fed on lucerne hay. The tracer technique involved the use of permeation tubes with pre-calibrated permeation rates ({\textquoteleft}pre-calibrated PR{\textquoteright}) of SF6. The {\textquoteleft}tracer CH4{\textquoteright} measurements were carried out for 5 days in digestibility crates housed within a covered yard. Sheep were transferred to calorimetry chambers for 3 days acclimatisation, followed by measurement of CH4emission for 3 days. Permeation tubes were recovered at the end of the animal trial and their {\textquoteleft}post-recovery PR{\textquoteright} determined after subsequent weighing for a 6-month period. Although the {\textquoteleft}tracer CH4{\textquoteright} was slightly lower (by 4\%) and had larger variation than the {\textquoteleft}calorimetric CH4{\textquoteright} values (18.8{\textpm}0.4 vs. 19.5{\textpm}0.6), the two measurement techniques did not differ significantly (P>0.05) in their CH4emission estimates. The {\textquoteleft}post-recovery PR{\textquoteright} was not different (P>0.05) from their {\textquoteleft}pre-calibrated PR{\textquoteright} values, and they were highly correlated to each other (r=0.98, P<0.0001). It is concluded that the tracer technique provides a reliablealternative method for CH4measurement in forage-fed sheep.}, issn = {1176-5283}, author = {Pinares-Patino CS and Holmes CW and Lassey KR and Ulyatt MJ} } @conference {41771, title = {Examination of pH in lot fed beef for Japan}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {436-440}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {Cattle lot fed for the Japanese market produce carcases of high value and thus downgrading based on meat quality represents a significant cost. The Meat Standards Australia guidelines for the rate of pH fall specify that carcases must not reach pH 6.0 before their temperature reaches 35{\textdegree}C, however limited experimental data suggests this is a common occurrence in heavy carcases produced for the Japanese market. Therefore a study was conducted to confirm this occurrence and to determine the impact of season on the incidence of fast pH fall. 811 carcases were examined from cattle fed for ~150 days, 411 in April and 400 in July. Initial pH (pHi) and temperature were measured on all carcases and then a sub-set of samples (200/season) were measured for traits such as colour, drip loss and protein solubility. pHi was measured on core muscle samples taken from the loin muscle between the 5th/6th ribs prior to entering the chiller. The pH at 35{\textdegree}C was predicted for a subset of 41 carcases based on data collected at the MSA site at the lumbarsacral junction using non linear regression. There was a significant relationship (P < 0.05) between pH at 35{\textdegree}C at the MSA site and the temperature at the sampling site at the 5th/6th rib used for determination of pHi. A large proportion of the carcases were outside the MSA pH/temperature window in both autumn (86\%) and winter (95\%). Season was found to have a significant effect on pH at 35{\textdegree}C (P < 0.001) and ultimate pH (P < 0.001) with higher values in the autumn and winter respectively. A high incidence of carcases exhibiting a fast pH decline at high temperatures was found, irrespective of season and the significance of this finding is discussed.}, issn = {1176-5283}, author = {Hopkins DL and Cassar JA and Toohey ES and Wynn PC} } @conference {42004, title = {Expression of keratin intermediate filament genes in wool follicles of wiltshire sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {332-338}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {Co-ordinated expression of keratin intermediate filament genes in the wool follicle is essential for the formation of the wool fibre. The expression patterns of three acidic (oKRT31, oKRT35, oKRT38), one neutral-basic (oKRT85) and one acidic inner rootsheath keratin (oKRT27) were localised by in situhybridisation in the wool follicles of Wiltshire sheep. All five genes show distinct expression patterns in the primary wool follicles of the face and lower leg, but have comparable keratinisation zones to their human orthologues. During follicle regression, the expression of these genes is first attenuated distally, gradually becoming restricted to proximal regions before terminating in dormant follicles. The involvement of the expression of oKRT27, oKRT31 and oKRT85, but not oKRT35 and oKRT38, in brush-end formation indicates specialised regulation of keratin expressionin the development of this anchoring structure. Intriguingly, significant differences in the expression of cortical oKRT31, oKRT35, oKRT38 and oKRT85 between primary and secondary follicles were identified.The association of asymmetrical expression of some keratins with follicle curvature raises the possibility of a role infibre crimp formation. Future studies of these and other keratins will generatean understanding of the structural basis of fibre attributes that could contribute to development of novel wool fibres for specific applications.}, issn = {1176-5283}, author = {Gordon SW and Yu Z-D and Nixon AJ and Pearson AJ} } @conference {42006, title = {Expression of the developmental regulators Msx1 and Msx2 in sheep skin varies with body region and wool growth pattern}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {345-350}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {The variability of fibre characteristics affects the processing performance of wool and therefore the value of the wool clip. These variations originate during development in utero, and manifest as patterns of fibre growth that differ between body regions. Two transcription factors, Msx1 and Msx2, have previously been linked to regional specification within the skin and alsoact as regulators of differentiation within the hair follicle matrix. In this study, we describe the expression patterns of Msx1and Msx2in multiple body sites of foetuses and adult crossbreed ewes. In foetal skin, the expression of both Msx1and Msx2was greatest in the regions of lower eventual follicle density. In adults, both anterio-posterior and dorso-ventral gradients were observed in Msx1expression across the fleece bearing skin. Higher concentrations of Msx1and Msx2transcripts were present in adultsthan foetuses, possibly reflecting additional roles in regulating the differentiation and growth of the wool fibre shaft. These results are consistent with the involvement of Msx1 and Msx2 in the development of skin regions, wool follicle growth, and anterio-posterior and dorso-ventral gradients of wool characteristics in sheep}, issn = {1176-5283}, author = {Craven AJ and Rufaut NW and Scobie DR and Nixon AJ} } @conference {41762, title = {The genetic relationship between heifer and cow fertility}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {388-391}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {Initial predictors of dairy bulls{\textquoteright} fertility proofs are currently limited to body condition score (BCS), milk yield and success of mating in the first 21 days (PM21) for their two-year-old lactating daughters. The first calving rate trait (CR42) is available after a cow has calved for a second time. Obtaining an earlier indication of fertility would be useful for genetic evaluation purposes. The aim of this study was to investigate the genetic and phenotypic control of heifer fertility in addition to investigating the relationship between heifer fertility and traits already included in the prediction ofthe fertility breeding value. Data were available on LIC{\textquoteright}s Sire Proving Scheme animals born from 1989 to 2003 and included records on 244,453 animals. Using data on the first calving, planned start of calving was defined as the day within contemporary group when greater than 10\% of animals had calved. A multivariategenetic analysis was undertaken with the traits PM21, CR42, BCS and 270-day milk yield recorded in lactating cows, in addition to a heifer fertility trait where success is defined as heifers that calve within21 days from the planned start of calving (CR21). The model fitted to these traits included contemporary group of the milking herd, breed proportions and age at first calving as linear and quadratic effects. The mean CR21 in this dataset was 71\%. Heifers failing to calve within 21 days of the herd{\textquoteright}s planned start of calving for heifers also had poorer fertility in first lactation, with a least-squares-mean of 75.5\% (s.e. 0.2) versus 81.5\% (0.1) for PM21 and 54.2\% (0.22) and 62.4\% (0.1) for CR42. The heritability estimate of CR21 was low (0.012), yet the genetic variation was comparable to other fertility measures. CR21 had a positive genetic correlation with CR42, indicating that CR21 may be a useful early indicator of fertility for use in genetic evaluations.}, issn = {1176-5283}, author = {Pryce JE and Harris BL and McNaughton LR} } @conference {41707, title = {Genetic technologies for deer breeding}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {91-94}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {The deer industry has made significant progress in developing and applying genetic tools to accelerate genetic gain. This paper briefly outlines the application of current tools (DNA parentage, DNA breed composition and genetic evaluation for growth and velvet), and then suggests a range of other tools which might be used in deer breeding in the future and makes brief comment as to their application. These tools include: genetic evaluation of a wider range of traits; economic indices, mate allocation software, breeding program diagnostic software, enhanced breed composition tests, single gene tests and whole genome selection.}, issn = {1176-5283}, author = {Archer JA and McEwan JC and Hall R} } @conference {41714, title = {Hair whorl patterns are related to age at puberty and milk-production traits in dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {130-135}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {The objective of this study was to measure facial hair whorl characteristics of Friesian-Jersey crossbred cows (n=658) and to investigate their association withmeasures of milk production, fertility and behaviour. Cows had 1 (n=581), 2 (n=10), 3 (n=1) or no facial hair whorls (n=66). Of those cows with one whorl, 66\% had whorls in the middle of the head, whereas 21\% had whorls low on their head and 13\% high on their forehead. Round whorls were present on 77\% of cows, while 23\% had non-round whorls. Fifty five percent of cows with round whorls were recorded as havinganticlockwise rotation and 16\% of cows as clockwise rotation. Cows with high hair whorlstended to reach puberty earlier on average than cows with lower whorls (P=0.07). Cows with higher non-round whorls also produced lower total milk and total solid yields, than cows with low whorls (P=0.01). No relationship was found between hair whorl characteristics and behaviour in this study.}, issn = {1176-5283}, author = {Young SK and McNaughton LR and Spelman RJ} } @conference {41698, title = {Impact of early age litter size on subsequent litter output in ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {39-43}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {Data from 28 performance recorded sheep flocks were evaluated to test for effects of litter size early in a ewe{\textquoteright}s life, on subsequent litter sizes. Ewes lambing twins at 2, 3 or 4 years of age had litters with on average 0.04 to 0.08 more lambs at each subsequent lambing than ewes lambing singles. The corresponding increases for ewes lambing triplets versus singles ranged from 0.23 to 0.26, with retention of the effect through successive litters. When data were adjusted to accountfor a ewe{\textquoteright}s lifetime genetic potential for prolificacy, evidence for an antagonistic environmental effecton litter size following a previous large litter was identified. This effect was approximately twice as high for triplets relative to singles (-0.19 to -0.32) when compared with twins relative to singles (-0.09 to -0.18), and declined in its effect on lambings more than one year later. It suggests that preferential treatment ofewes based on their previouslambing performance might improve their subsequent lambing performance. Culling two tooth ewes based on a single lambing record is unlikely to be economically viable, but there may be situations where reduced flushing of two tooth ewes prior to mating might be justified in prolific commercial flocks. The power and limitations of using data from performance recorded flocks to make recommendations relating to management decisions in commercial flocks is discussed.}, issn = {1176-5283}, author = {Amer PR and Jopson NB and Cocks J and Scarlet AL} } @conference {41765, title = {Induced physical distension of rat mammary glands accelerates the onset of apoptosis and involution compared with milk accumulation alone : Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {403-406}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {Extended periods of milk accumulation result in reduced milk secretion, increased apoptosis and eventually, involution of mammary glands. The subsequent change in epithelial cell shape from a cuboidal to a flattened morphology as the alveoli distend with milk may initiate changes in protein and gene expression (mechanotransduction) triggering the process of involution (Davis et al., 1999).}, issn = {1176-5283}, author = {Phyn CVC and Dobson JM and Davis SR and Stelwagen K and Singh K} } @conference {41710, title = {Integrated livestock management ... challenges and opportunities of farming deer with other livestock}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {107-116}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {A recent survey indicated that approximately 67\% of deer farmers integrate sheepand/or cattle on their deer unit to better match feed demand with the seasonal pattern of pasture growth, maintain pasture quality, particularly during lactation and to control weeds. Integrated stock policies also allow for improved financial risk management and provide flexibility to adjust stock numbers in response to market signals and feed supply. There is evidence from the sheep and beef industries that productivity can be increased from the integration of sheep and cattle compared to a single species system. There is limited information for the integration of sheep and cattle with deer so an assessment of the {\textquoteleft}challenges and opportunities for co-grazing deer with other livestock{\textquoteright} must inevitably rely on extrapolation of knowledge from the co-grazing of sheep, cattle and goats of which there is an extensive literature. This paper identifies the key knowledge needed to meet the challengesand identify the opportunities of grazing deer withother livestock.}, issn = {1176-5283}, author = {Nicol AM and Griffiths WM and Edwards GR} } @conference {41961, title = {Internal parasites and productivity in farmed deer}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {102-106}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {The aim of this brief review is to summarise current knowledge of the effects of internal parasites (lungworm and gastrointestinal nematodes) on productivity of farmed red deer. This review, largely based upon published data, highlights gaps in the literature and draws attention to topics for future research.}, issn = {1176-5283}, author = {Hoskin SO and Johnson M and Swanson J} } @conference {41732, title = {International drivers for animal welfare change and implications for New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {226-231}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {Standards of animal welfare accepted in the international (mainly European and North American) marketplace are influenced by a wide range of factors, including lobby groups and retailers. In addition, voluntary labelling of products (one of the tools advocated by lobbyists and retailers) is likely to have considerable influence over consumer purchasing choices (for foods derived from animal friendly products and production systems). The EU is determined, through a combination of policy adjustment, research and monitoring of animals, and provision of information, to make improvements to the welfare of animals that contribute to the food supply of European consumers. The changed regimefor CAP payments will mean that systems for monitoring livestock welfare will be in place in Europe from 2007. The EU{\textquoteright}s Welfare Quality research project will have a draft set of welfare monitoring standards available for {\textquotedblleft}road testing{\textquotedblright} at the beginning of 2007. Similarly, validated measurement tools that are relevant to New Zealand conditions are required (to facilitate continued success in premium-priced welfare-sensitive markets). Ideally, the measurement tools and systems need to be outcome-based and applicable to the assessment of all aspects of welfare covered under the Five Freedoms and in New Zealand{\textquoteright}s production systems.}, issn = {1176-5283}, author = {Matthews LR} } @conference {41988, title = {Iodine deficiency in dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {248-254}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {Clinical signs of iodine deficiency (e.g. non-visible oestrus, low first service conception rate, stillbirths), plus low (<45 nmol/L) serum thyroxine (T4) concentrations were observed in dairy cows from 12 farms in the Manawatu. Goitre, as determined by diffuse thyroid hyperplasia,plus significantly (p<0.05) increased thyroid size, weight and thyroid:bodyweight ratio, was found in 16\% (6 of 38) of stillborn calves from these farms. Goitre was present in calves from 42\% (5 of 12) of the herds. One of these farms was chosen to investigate temporal changes in concentrations of the thyroid hormones, thyroxine (T4) and tri-iodothyronine (T3), as an indicator of iodine status, and to attempt to determine the optimum time for sampling. Blood samples were collected from a cohort of animals from the herd (20 representative animals from 400 cows) 8 times over a 12 month period, for measurement of total serum iodine (TSI), T3 and T4 concentrations in both individual cows and pooled (10 cows) samples. T4 was maximal in June (58.6 nmol/L) and lowest (39.2 nmol/L) in October (P<0.05). Between November and Augusts meanTSI varied (NS) from 31 {\textpm} 9 to 47 {\textpm} 9 {\textmu}g/L, but was significantly (P<0.01) higher in October (91 {\textpm} 16 {\textmu}g/L). T4 concentrations were(P<0.05) related (r = 0.35) to TSI between November and August (7/8 blood samplings), but were widely divergent (r = 0.08) in October. Concentrations of T3 were unrelated to TSI (r= 0.07). In pooled samples, concentrations of TSI, but not T3 or T4, were closely related to the mean concentrations in individual animals. An iodine-response study was also carried out on the same herd. Half the herd (200 of 400) were given (6 mL i/m) iodised oil (Flexidine, Bomac) before mating and before calving. The pregnancy rate in anoestrous cows treated with iodine was 13.9\% higher than in untreated cows. It was concluded that T4 (individual animals) or TSI (pools of 10 cows) give equivalent information about the iodine status of a herd, except in the post calving period. However, the reference range needs to be validated by further response trials.}, issn = {1176-5283}, author = {Anderson PD and Dalir-Naghadeh B and Parkinson TJ} } @conference {41960, title = {Johne{\textquoteright}s Disease : Management of a challenging disease}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {95-101}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {In the last 20 years Johne{\textquoteright}s disease, caused by infection with Mycobacterium paratuberculosis (Map), has emerged as one of the most important bacterial diseases affecting productivity in New Zealand farmed deer. In addition to clinical losses, subclinical infection results in reduced growth rates of young deer, lower reproductive performance and lighter velvet weights. Traditionally, microbial culture of faecal material or gut tissue has been used to confirm the presence of infection. The Disease Research Laboratory has recently developed a refined ELISA test thatmonitors IgG1 antibody (Paralisa) specific for antigens expressed uniquely by M. paratuberculosis. This test has acceptable sensitivity (75-91\%) and specificity (>98\%) for the detection of subclinically affected animals. The use of this test in severely infected deer herds can reduce the prevalence of reactors from high (>40\%) to low levels (<5\%) within 2-3 years and result in the elimination of clinical disease. Clinically detectable Johne{\textquoteright}s disease represents a minor proportion of the total number of animals infected in a herd so it is also important to have diagnostic tests that detect subclinically infected animals. Using the Paralisatest, it is now possible to implement management systems to electively remove infected deer to increase production and reproductive performances.}, issn = {1176-5283}, author = {Griffin JF and Rodgers CR and Liggett SJ and Bell A and Mackintosh CG} } @conference {41968, title = {Landcorp Farming Lecture : Genomic selection for accelerated genetic gain in livestock}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {143-146}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {The sequencing of a number of the livestock genomes and developments in genotyping technology has made it possible to genotype animals for tens of thousands of markers relatively cheaply. Genomic selection exploits this information to calculate genomic breeding values (GEBVs), as the sum of the effects of small chromosome segments across the genome. Effects of chromosome segments are first estimated in a large population with phenotypic information. In subsequentgenerations, only marker information is required to calculate GEBVs. Accuracies of GEBVs calculated for animals with marker information only, can be as high as 0.85. Results from analysis of real data from dairy cattle suggest approximately 30,000 single nucleotide polymorphism markers will be required to calculate GEBVs with maximum accuracy. Chromosome segment effects should be estimated from at least 2000 phenotypic records. A trial of genomic selection in the Australian Holstein population, with 384 bulls typed for 9919 markers, achieved accuracies of GEBVs of up to 0.82, despite sub optimal marker density and limited number of phenotypic records. In dairy cattle, maximum genetic gain using genomic selection will be achieved by selection of young bulls for widespread use without progeny test, allowing a halving of the generation interval.}, issn = {1176-5283}, author = {Hayes BJ and Goddard ME} } @conference {41720, title = {LoinMAX and MyoMAX : Taking DNA marker tests from the research environment to commercial reality}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {160-162}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {Meat yield is an important component of most sheep breeding programmes. To improve meat yield, breeders use a variety of tools including marker assisted selection (MAS). Ovita funded AgResearch to develop two marker tests to assist in selection for superior meat yield. These have been branded MyoMAX TMand LoinMAX TMand originated from quantitative trait loci (QTL)studies over the past decade. In both cases the development of these commercial marker tests involved refining the QTL locations, identifying informative marker haplotypes and validating these in industry flocks. Both the LoinMAX TMand MyoMAX TMbeta tests were field validated using a numberof commercial breeders. The validation process showed that the phenotypic effects of both LoinMAX TM and MyoMAX TM were significant in different genetic backgrounds and that there were no negative correlations between the presence of LoinMAX T Mand MyoMAX TM with other traits, such as meat quality and growth rate. Both LoinMAX TM and MyoMAX TM have now been successfully commercially launched byCatapult Genetics Ltd and are being widely used in industry.}, issn = {1176-5283}, author = {Campbell AW and McLaren RJ} } @conference {41977, title = {Maternal constraint in sheep breeds with diverse birth weight}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {187-191}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {Reciprocal crosses of Shire and Shetland ponies and transferring embryos between small and large breeds of horses and pigs have shown that maternal size, ratherthan foetal genotype, is the primary determinant of birth size. In the present study, 40 Cheviot (C) ewes and 40 Suffolk (S) ewes were split into two groups. Each group was mated to either two Suffolk rams or two Cheviot rams to generate CC, CS, SC and SS lambs. Birth weights differed significantly (P<0.01) between the four lamb genotypes (CC 4.12 {\textpm} 0.21; CS 4.43 {\textpm} 0.23; SC 5.08 {\textpm} 0.19; SS 5.17 {\textpm} 0.19, kg). Furthermore, lower birth weight was significantly (P<0.01) associated with lower maternal circulating plasma placental lactogen (oPL) concentrations in the Cheviot dams at days 90 (C 25.8 {\textpm} 10.0 vs. S 71.8 {\textpm} 11.6, ng/ml) and 110 (C 84.5 {\textpm} 16.8 vs. S 175.9 {\textpm} 19.0, ng/ml) but not at day 130 of gestation. These results indicate that the size of the ewe affects the intrauterine development of her lamb. Moreover, the lower concentrations of oPL in the Cheviot dams may have contributed to the constraint observed in foetal growth.}, issn = {1176-5283}, author = {Jenkinson CMC and Kenyon PR and Blair HT and Breier BH and Gluckman PD} } @conference {41999, title = {The mechanical properties and lesion score of the sole and white line horn of front and hind claws of heifers prior to and during first lactation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {307-311}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {The aim of this experiment was to study the incidence of lameness and the pattern of lesion formation in the sole horn during the pre- and post-partum period of first lactation Holstein Friesian heifers and to compare these to mechanical testing of the hoof horn strength and with the breed society (Holstein Friesian) index of classification for conformation (HUKI) to compare heifers susceptibility to lameness. Samples of sole hoof horn were taken from all claws of 20 heifers at 144 and 40 days pre-partum and 50, 100 and 150 days post-partum. Simultaneously, all claws were assessed for the lesion score in the sole horn. Locomotion score was assessed weekly and heifers were conformation scored for the Holstein UK Index (HUKI). Hoof samples were analysed for elastic modulus and punch resistance. Punch resistance of the sole horn was significantly greater in front claws when compared to hind claws. The punch resistance, elastic modulus, lesion score and locomotion score increased significantly during the post-partum compared with the prepartum period. post-partum elastic modulus and punch resistance were significantly negatively correlated to increase in lesion score and locomotion score between measurement periods and positively correlated to the breed society conformation index (HUKI) score for legs and feet. Mechanical tests reflected the changes in housing and in haemorrhage levels that occurred between 144, 40 pre- and 100 days post-partum and there may be a potential to select animals for increased hoofhorn quality and reduce wearrates during lactation.}, issn = {1176-5283}, author = {Winkler B and Margerison JK} } @conference {42015, title = {Metabolic feed efficiency - opportunities for selection in dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {392-398}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {A literature review and simulation study is presented to investigate the potential role of metabolic feed efficiency in dairy cattle breeding programmes. Metabolic efficiency is generally calculated as the difference between actual feed intake and expected feed requirements and as a result is a residual term, hence it is often referred to as residual feed intake (RFI). There is evidence of genetic variation in RFI in poultry, sheep and beef cattle. Heritability estimates inbeef cattle are moderate (0.14 to 0.43). Heritability estimates in dairy cattle range from zero (no genetic variation) to moderate (0.38). RFI is positively genetically correlated with feed intake, so more efficient animals tend to eat less. Information is sparse, but suggests there is no genetic correlation between milk production and RFI. Genetic correlations between health and fertility traits and RFI in cattle have not been established, but evidence frommice and pigs suggests unfavourable correlations between RFI and fertility. Estimating the genetic relationships between RFI and health and fertility in dairy cattle is required. The identification of genetic markers that explain sizeable variation in RFI, or an easily measured correlated trait would be the preferred options to enable selection for RFI in dairy cattle, ideally breeding values for RFI would be estimated and included as part of a multiple-trait selection index.}, issn = {1176-5283}, author = {McNaughton LR and Pryce JE} } @conference {41739, title = {Monensin controlled release capsules for improved production and mitigating methane in dairy cows fed pasture}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {266-271}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {Mitigation of ruminant methane is an important component of New Zealand{\textquoteright}s strategy to lower greenhouse gas emissions. Methods for mitigation must be profitable, easily achievable for producers and be applicable to a wide range of farming systems and topography. The rumen ionophore monensin, is potentially capable of meeting these requirements, but its effects on both production and methanogenesis have been variable with forage diets.A trial was undertaken with 60 lactating Friesian/Holstein dairy cows in early {\textendash} mid lactation and fed pasture over a 3 month period, to measure effects of a commercially available monensin controlled release capsule (CRC) on milk production, rumen metabolites and methane production. Monensin had no effect on fat or protein yield and therefore milksolids yield, 1.68 kg/day for both groups of cows, was unaffected. Rumen volatile fatty acid ratios, measured in 10 animals, were not affected by monensin treatment and average methane production (323 g/day) was similar for both groups (P=0.961). The absence of benefits from monensin for either production or methane mitigation in dairy cows fed forages as a sole diet are in line with other published data. Monensin CRCs will not provide a profitable route for methane mitigation in ruminants grazed on pasture.}, issn = {1176-5283}, author = {Waghorn GC and Clark H and Taufa V and Cavanagh A} } @conference {41760, title = {Multiple trait national genetic evaluation for cow longevity}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {377-381}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {In New Zealand genetic evaluation for cow longevitywas based on a single trait model where the phenotypic record was actual or predicted days survived in the milking herd. Cows which were yet to express their actual longevity received a predicted phenotypic record based on the milk production and liveweight production values, traits other than production (TOP), and fertility breeding values. The prediction equation was a proxy for a multiple trait model. At the time of implementation a full multiple trait model was not computationally feasible. A study was undertaken to investigate the feasibility of developing a full multiple trait model. The multiple trait model has the advantage of incorporating the appropriate genetic relationships among the predictor traits and the longevity traits, as well as allowing different genetic correlations among the individual longevity traits. The first stage of the study was to estimate the genetic correlations among all traits under genetic evaluation and two longevity traits; survival from first to second lactation and first to fifth lactation. Data used for genetic correlation estimation was from first lactation records from the Sire Proving Scheme herds for seasons 1987 to 2005. The two fertility traits, 42 day calving rate and percent mated in the first 21 days, had the highest genetic correlations with the longevity traits, ranging from 0.84 to 0.27. Body condition score, management TOP and the milk production traits had moderate genetic correlations with the longevity traits, ranging from 0.42 to 0.24. Somatic cell score, udder support, udder overall, legs, capacity and dairy conformation had low genetic correlations with the longevity traits but were significantly greater than zero. Four longevity traits, and 9 predictor traits were included in a national genetic evaluation for cow longevity. The 9 predictor traits were chosen from the traits that had significant genetic correlations with cow longevity and contained genetic information that was not already included in other predictor traits. Comparisons between sire breeding values from the single trait model and the multiple trait model show good agreement with a correlation of 0.95 for Animal Evaluation enrolled sires. Investigation of the sire breeding values shows that the multiple trait model puts a greater emphasis on cow fertility than the single trait model.}, issn = {1176-5283}, author = {Harris BL and Montgomerie WA} } @conference {41705, title = {New perspectives on deer reproduction , growth and production efficiency}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {78-81}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {Reproduction and growth intersect during lactation. Lactation is the period when the initial productivity of the calf is expressed and much ofthe potential production efficiency is set. Examples of recent advances in our understanding of productivity systems in deer farming are summarised. Experimentation in lactation has highlighted new information that can improve on-farm production. Recent research has given an understanding of the lactational outputs of the hind rearing either a red or F1 wapiti crossbred calf. Further experimentation has examined the role of protein and energy in determining calf growth. Other research has quantified both hind and calf intake and live weight change during late lactation. The impacts of these developments are discussed.}, issn = {1176-5283}, author = {Stevens DR and Asher GW and Archer JA and Scott IC and Ward JF and O{\textquoteright}Neill KT and Corson ID} } @conference {41701, title = {Parturition duration and birthing difficulty in twin and triplet lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {55-60}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {The primary objective of this study was to investigate the relationship between parturition duration, localised oedema in lambs (as determined by post mortem findings) and lamb survival. Parturition behaviour was recorded for 131 mixed age Coopworth ewes and their 303 lambs (twins n=180; triplets n=123). Twin lambs and first born triplet lambs that did not survive tothree weeks of age took at least twice as long to be born than lambs that survived (P<0.05). The duration of parturition for lambs that died and had moderate to severe subcutaneous oedema was more than three times longer than for those that had none and minor localised subcutaneous oedema at post mortem examination (P<0.05). Further research is required to understand the factors contributing to prolonged parturition for twins and triplets. This information is needed so that appropriate management techniques and animal breeding programmes can be developed to reduce birthing difficulties (dystocia) and lamb mortality rates.}, issn = {1176-5283}, author = {Everett-Hincks JM and Dodds KG and Kerslake JI} } @conference {41756, title = {Preliminary observations on fresh and healed scars in deer skins}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {356-360}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {To improve knowledge of where frequent damage to deer skins was occurring, and how to quantify it, studies were carried out at deer slaughter plants (DSPs) in the South Island, New Zealand. Skins from supplying farms were identified using a pattern punched into the fresh skin. In Part A, scarring was assessed following de-hairing and pickling, in skins from three suppliers at each of five slaughter plants. On average there were 4 (range 0-17) fresh and 7 (range 0-85) healed scars per skin. Effects of supplier and DSP on the number of fresh and healed scars were observed (P<0.001), with some achieving very low levels of damage, and some showing frequent, consistent forms of damage. In Part B, skins were assessed at wet-blue and finished leather stages, from deer killed in nine slaughter groups over three days at one DSP. In wet-blue skins, slaughter groups differed in the number (P<0.001) and severity (P<0.01) of healed scars, while in finished leather, slaughter groups differed significantly in damage score (P<0.05). Together the studies showed effects of supplier and DSP on the amount, severity and type of deer skin damage.}, issn = {1176-5283}, author = {Scobie DR and Pollard JC} } @conference {41692, title = {Presidential Address 2006: Females are in fashion}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {1-8}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {It is with some trepidation that I explore this topic with you. Please bear with me and don{\textquoteright}t throw your barbs until the end, when I would imagine there will be at least some of you that I have not offended in one way or another. I don{\textquoteright}t seek to upset or embarrass any particular person, but I simply want you to think about what I have to say. Some of the references I use are not the kind of reference you could track down easily, but let us just say that was a protocol brought into science by men, set it to one side and see where a more inclusive style of language might lead us.}, issn = {1176-5283}, author = {Scobie DR} } @conference {41749, title = {Production and physiological indicators to select cows suitable for extended lactations}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {315-319}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {Individual cows vary in their ability to maintain milk production for an extended lactation. Identifying production and physiological markers to indicate cows suitable for extended lactations would allow dairy farmers to make early decisions to withhold mating of individual cows or to continue milking specific nonpregnant cows through the winter months. Fifty-six genetically divergent overseas and New Zealand Holstein Friesians were allocated to three pasture-based dietary treatments (0, 3 and 6 kg concentrate DM/cow/d) and mating was withheld to target a 670-d lactation. Within each treatment there was little correlation between animal evaluation index values and milksolids (MS) production during the extended lactation period (>296 days in milk; DIM). There was a positive correlation between MS yield from the initial normal season (<296 DIM) and extended lactation MS production; and a negative correlation between body condition score (BCS) at theoretical dry off date (~296 DIM) and extended lactation MS yield. Plasma hormone and metabolite data from wk 1-10 postpartum demonstrated a positive association between nonesterified fatty acid levels and extended lactation MS production, whereas glucose,insulin, and insulin like growth factor-1 were negatively associated with extended lactation MS production. Overall, data indicate that the animal evaluation index is not a good indicator of animals suitable for extended lactation, however normal season milk production, early lactation plasmahormone and metabolite and late lactation BCS data may be useful to identify animals that will undergo a successful extended lactation.}, issn = {1176-5283}, author = {Kay JK and Aspin PW and Phyn CVC and Roche JR and Kolver ES} } @conference {41973, title = {Prospects for genome wide selection in the New Zealand livestock industries}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {162-168}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {A number of DNA marker applications aid genetic selection within subpopulations of New Zealand{\textquoteright}s livestock farming industries. Advances in genomic tools have opened the possibility of genotyping individuals for a large set of markers, enough to have a large proportion of the genome {\textquoteleft}tagged{\textquoteright} with at least one of these markers. This creates opportunities for genome wide selection (GWS) {\textendash} the selection of breeding animals based on very large numbers of marker genotypes. There are a number of requirements for GWS to work, including the existence of genotyping technology to provide genotypes at a sufficient density, tractable statistical methods for estimating marker effects to use in prediction models and suitably phenotyped populations which when genotyped allow estimation of relationships between markers and traits. Additional phenotyped populations are required to validate their predictive ability and demonstrate economic benefits to breeders and to the commercial tier. A high density genotyping platform is available for cattle, but may need further developments. Plans are underway for a similar platform for sheep, but not for deer. The dairy industry is well placed to implement GWS, as there is a large bank of DNA samples of industry sires representing most of the genome variation present. Genotyping these animals will allow marker effects to be estimated and the reduced generation interval arising from selecting young sires should easily overcome any decrease in selection accuracy compared with progeny testing. Industry structures are likely to evolve to allow a return to entities undertaking GWS. GWS will be mostbeneficial for traits with low heritability, that cannot be measured on selected parents and/or that are expensive to measure. Genes of known effect may continue to be accounted for individually, particularly if they exhibit non-additive effects.}, issn = {1176-5283}, author = {Dodds KG and Amer PR and Spelman RJ and Archer JA and Auvray B} } @conference {41758, title = {Puberty in Angus bulls from lines selected for heifers{\textquoteright} age at puberty}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {365-369}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {In reproductive studies of juveniles, puberty has to bedefined and decisions made on how to record it in both sexes. Our recording criterion for age at puberty in heifers is the date (and hence age) of first behavioural oestrus. This is a heritable trait under New Zealand grazing conditions, with a realised heritability estimate from a long-term AgResearch selection experiment of0.27 {\textpm} 0.04. Data published in Edinburgh by R. B. Land suggest that male puberty traits in mammals are also inherited and are related to female puberty traits, but the difficulty is in measuring puberty in males. Our indicator in the selection experiment mentioned above is scrotal circumference (SC), where single SC records had a heritability of 0.40 {\textpm} 0.03 and a repeatability over time of 0.67 {\textpm} 0.01. Our objective in the present study was to determine whether another indicator might be semen quality, derived from a serial assessment of semen samples over the likely puberty period, and to compare this with serial SC records. The selection experiment was established in 1984/85 with Angus cattle. Genetic selection was applied in one line ({\textquoteleft}AGE-{\textquoteright}) for lower age at puberty in heifers, and in a second line ({\textquoteleft}AGE+{\textquoteright}) for greater age at puberty in heifers. SC data were monitored each year in bulls from both lines. Young bulls from the 1997 and 1998 calf crops (25 per year) were also monitored for semen quality from about 9 to12 months of age. Semen samples were obtained by ampullary massage, and quality was assessed on a warmmicroscope stage, using a 0-5 scale. Semen score was plotted against SC from means for each breeding line and month, and the correlations over both lines were 0.98 in 1997 and 0.86 in 1998. The AGE- line was superior to the AGE+ line by 0.81 semen score units (P < 0.001) and by 4.0 cm (14\%) in SC (P < 0.001). Results showed that semen quality was associated with SC, and that both had responded to heifer puberty selection. It was easier to measure SC as the male puberty trait.}, issn = {1176-5283}, author = {Morris CA and Amyes NC} } @conference {41995, title = {Quantifying the importance of submission rate to artificial breeding on reproductive performance and profitability in dairy cattle herds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {285-292}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {Dexcel{\textquoteright}s Whole Farm Model (WFM) allows the user to construct a mating policy using dates for anoestrous treatment, artificial breeding (AB) and bull mating with corresponding levels of heat detection efficiency. The model then predicts the outcome of the mating programme for each individual animal using an approach based on physiological events, represented by algorithms incorporating current best knowledge. Four commercial dairy farms were initialised in WFM by describing the farm set-up and management decisions for the 2005/06 season. A range of feeding, production and reproduction indicators was used to validate the model predictions against that observed. All four farms had an observed 3-week submission rate (SR) of about 90\%. An alternative scenario with SR at80\% was created for each farm by simulating reduced oestrous detection efficiency during AB. The eight scenarios were then run for 20 random simulations over three consecutive years. The trend was for SR 90\% to result in more milksolids in the second and third years, improved reproductive outcomes and, despite higher AB costs, an increased (P<0.05) economic farm surplus of $80+/ha. This exercise demonstrated that the WFM is capable of simulating reproductive performance in dairy herds and holistically linking this performance to productivity and profit over successive seasons.}, issn = {1176-5283}, author = {Beukes PC and Tiddy RM and Burke CR and Levy G and Lancaster JAS} } @conference {41949, title = {Reconciling the differences between the length at which lambs{\textquoteright} tails are commonly docked and animal welfare recommendations}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {32-38}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {The rationale for the length at which lambs{\textquoteright} tails are docked was investigated by comparing lambs with No-tail, Short, Medium (covering the vulva in ewe lambs and at a similar length in males), Long, and Undocked tails. In Experiment 1, dagging and shearing required additional effort in Long and Undocked animals. There were no differences in average dag scores, but few lambs had dags. Shorter tail docking resulted in significantly (P<0.05) lighter recto-coccygeal muscles (from 8.9 {\textpm} 0.5g in Undocked to 6.6 {\textpm}0.4g in No-tail). The tail stumps of half of the No-tail, Short and Medium showed evidence of neuroma development and degenerative nerve changes compared with few of the Long and Undocked lambs. In Experiment 2, restlessness, an indicator of pain and distress in rubber ring docked lambs, tended to be more pronounced the shorter the tail was docked. Experiment 3 compared typical farm practices (Short), with the AWAC-recommended length (Medium). The slightly longer length was associated with (1) more lambs difficult to dag (11/44 Medium vs. 4/44 Short; P<0.001); and (2) no perceived benefits in increasing tail length. While the traditional Short and Medium tails appear to be the most appropriate, pain and distress, neuroma development and rectal muscle function may also be affected by tail length. It is yet to be determined if these additional factors justify a change to current practicesbut that possibility is considered unlikely.}, issn = {1176-5283}, author = {Fisher MW and Gregory NG} } @conference {42018, title = {Regulation of milk protein synthesis in the bovine mammary gland : A proteomic approach}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {407-412}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {The molecular mechanisms that regulate milk protein synthesis in the dairy cow are not well understood. We used a proteomic approach to identify potential regulators of milk protein synthesis among the endoplasmic reticulum (ER) proteins. Mammary tissue was collected from mid-lactation dairy cows treated with atropine (Atr; decreased milk production), growthhormone (GH; increased milk production) or vehicle alone. Fractions enriched for ER associated proteins were prepared by differential centrifugation and then resolved by 2-dimensional electrophoresis (2-DE). Proteins were visualised using colloidal coomassie G-250 and the phosphor-protein specific stain, Pro-Q Diamond. We identified 4 significant (P<0.05) and 9 marginally significant (P<0.15) spots that were differentially expressed between treatment groups. Six spots were subjected to LTQ ion trap tandem mass spectrometry and 2 proteins were identified with a high level of confidence: major vault protein (MVP) (27\% of the control level after GH treatment, P<0.05), and heat shock 70Kda protein 8 (HSPA8) (41\% of the control level after Atr treatment, P <0.01). Western blotting showed a 24\% decrease in HSPA8 following Atr treatment (P<0.10) and a 55\% decrease in MVP following GH treatment (P<0.10). These results provide a focus for further investigation of the role of MVP and HSPA8 in influencing milk production.}, issn = {1176-5283}, author = {Smolenski G and Bond JJ and Wheeler TT and Roy NC and McNabb WC and McCoard SA} } @conference {41695, title = {Response of calves to different levels of mixed species gastrointestinal parasite infection}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {23-27}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {The effect of different levels of parasite infection was studied in 5-month old calves. Eighty-four calves were dosed with 0, 1000, 2000, 4000, 7000 or 10000 parasite larvae (L3) per day for 6 weeks (90\% Cooperia, 10\% other species), or were drenched 3-weekly, whilst grazing in one mob. Worm burdens were then determined in 3 calves per treatment. The remaining calves then grazed together for 11 weeks to determine carryover effects, during which they were all drenched at weeks 5 and 9. At the end of L3 dosing, there were no liveweight differences, but by week 5 of the carryover period, calves receiving 10000 L3 per day were 12 kg lighter than drenched or 0 L3 calves (P<0.05). This difference was maintained for the rest of the experiment. Cooperiaburdens (76000/calf) in 10000 L3 calves were at least double those on all other treatments (P<0.001). There was no relationship between L3 dose and worm burden for the other parasite species, or L3 dose and faecal egg count. This experiment has shown that for calves dosed with less than 10000 L3 per day, drenching does not increase liveweight gain when the parasite larvae are 90\% Cooperia.}, issn = {1176-5283}, author = {Burggraaf VT and Puha MR} } @conference {41980, title = {Responses to selection in ryegrass staggers lines of sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {204-208}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {Ryegrass Staggers (RGS) is predominantly a summer/autumn metabolic disorder in ruminants, caused by ingestion of the lolitrem-B toxin from endophyte-infected perennial ryegrass, and it is common in New Zealand. It causes lack of neuromuscular co-ordination in susceptible animals under stress, e.g. when mustered by sheep dogs. It is of welfare concern, and it is costly to farmers because it severely compromises grazing management. A flock was established at AgResearch in 1993, with two lines bred for resistance (RGS-R) or susceptibility (RGS-S) to RGS. Lambs are scored for susceptibility each year, when grazing on high endophyte pastures, and mustered by sheep dogs. In 2005 and 2006, 94\% and 91\% of lambs respectively in the RGS-S line showed clinical staggers, when grazing together with the RGS-R line which had 2\% and 6.5\% of clinical cases, respectively (P < 0.001). Using the latest standardised RGS scoring system, the heritability estimate of resistance/susceptibility to RGS was 0.36 {\textpm} 0.04. To understand more about why and how the RGS lines differ, blood samples were taken from the breeding-ewe flock (n = 126) in June 2005, outside the usual RGS and facial eczema season. Compared with the RGS-R line, the RGS-S line ewes had a 23\% higher activity (P < 0.001) of aspartate transaminase (AST), an enzyme indicating hepatic or muscular damage; there were similar findings inewes sampled four weeks apart (between-animal repeatability for AST = 0.85). In plasma samples from selection-line yearling females (two birth years; n = 95), the RGS-S line had 27\% and 37\% higher AST and alanine transaminase activities, respectively (both P < 0.001), and a 38\% higher creatine kinase activity (P < 0.05) than the RGS-R line. One explanation of these results is that, compared with the RGS-R line, selection in the RGS-S line may have changed two functions, a reduced ability to detoxify lolitrem-B, and an increased sensitivity to stress expressed as a tendency to show increased muscle tetany and damage.}, issn = {1176-5283}, author = {Morris CA and Amyes NC and Orchard RL} } @conference {41989, title = {Restricted postpartum feeding in grazing dairy heifers decreases milk production but does not lengthen oestrous interval}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {255-260}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {The aim of this study was to determine the effects of pasture allowance postpartum on the initiation of ovarian activity, metabolite and hormonal secretion, and milk production. After calving, thirty six HolsteinFriesian heifers (BCS 5.0) received either unrestricted pasture allowance (UNR; n=18) or restricted (RES; 73\% dry matter intake of the unrestricted group;n=18) pasture allowance. The LW was lower (P < 0.05) for the RES group than the UNR group. Body condition score of all heifers decreased after calving in both groups. The mean time to ovulation was similar for UNR 50.0 and RES 50.3 sed. 8.2 days after individual calving date. The daily average from week 2 for milksolids, protein and lactose yield was lower (P < 0.05) in the RES group. Plasma concentrations of insulin were lower (P = 0.0085) in the RES group when compared to the UNR group. Glucose concentrations was lower (P = 0.016) in the RES group. Plasma concentration of NEFA was greater (P = 0.001) in the RES group. There was an interaction with treatment differences decreasing by week 11 and 12 for glucose (P =0.001) and NEFA (P =0.006). Plasma concentrations of leptin (P = 0.013) and IGF-I (P = 0.026) were lower in the RES. No differences, associated with postpartum nutrition, were found for plasma GH. Restricted feeding postpartum had no effect on days to first postpartum ovulation but decreased liveweight, milk production and affected some metabolic hormones during postpartum.}, issn = {1176-5283}, author = {Chagas LM and Gore PJS and MacDonald KA and Blache D} } @conference {41745, title = {Semen parameters of cloned bulls}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {297-302}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {Bulls cloned from the somatic cells of genetically elite sires can make a major contribution to genetic improvement and the rate of dissemination of improved genetics within both the dairy and beef industries. However, little is known about the physiology of clone males and the quality of their semen in particular. This paper reports on the semen characteristics of five cloned Friesian bulls, compared to the two {\textquoteleft}Donor{\textquoteright} bulls from which three and two of the clones were derived by nuclear transfer, respectively, and an age matched control bull. Three batches of frozen semen from each of these eight bulls were obtained from a commercial AB centre and analysed. Four straws from each batch of semen were thawed, pooled and made up to 1mL with RSD-1 diluent and sub-samples taken to evaluate viability, motility, morphology, migration (using a synthetic mucus) and DNA damage. Viability, motility and migration assays were performed immediately after thawing (0 hours) and repeated after 3 hours of incubation at 38{\textdegree}C. An additional straw from each semen batch was used to determine sperm concentration and proportion of diploid cells. There were significant differences (P<0.05)between individual bulls in all parameters except diploid cells (0.16 {\textpm} 0.05 \%), sperm DNA damage (4.41 {\textpm} 1.13\%) and normal sperm (93.3 {\textpm} 6.7\%). The differences in viability (range 74.9 to 54.9\% at 0 hours; 49.6 to 22.5\% at 3 hours), motility (59.2 to 28.3\%; 52.5 to 29.2\%) and migration (vanguard distance 68.3 to 42.5 mm; 38.8 to 12.5mm and running distance (>150 sperm) 33.3 to 23.3mm; 20.4 to 6.7mm) were greater at 3 hours than at0 hours reflecting individual variation in rate of change in parameters over time. However, examination of the variation between clones within a clonal family or line and between lines revealed that this was similar to the overall individual variation, indicating that members of a clonal family are not more uniform. Nonetheless, these results indicate that the samples of semen from the cloned bulls were as good as those of the original donor bulls and fit for commercial use to potentially disseminate elite genotypes.}, issn = {1176-5283}, author = {Smith JF and McDonald RM and Wells DN and Cox NR} } @conference {41726, title = {Sperm DNA damage after scrotal insulation in rams}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {192-197}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {Human male fertility is in decline and one reason given for this is the increased incidence of sperm showing chromosomal or DNA damage. Previous work in laboratory and farm animals as well as humans has shown that elevated testicular temperatures increases the incidence of sperm with DNA damage. As part of a study into the effect of temperature on mutation rate in spermatozoa using rams as a model, measurements of sperm DNA damage were also recorded. Twelve mature Dorset x Romney rams, were trained to AV semen collection. Scrotal insulation harnesses were applied (plastic bag with cotton wool insulation inside a rubberised fabric protection cover) to two groups of 6 rams for either a 24 or 48 hour period at day 0. Semen was collected on days -4 and 0 as control samples for each ram before treatment and days 3, 7, 10, 14, 17, 21, 24, 28, 31, 35, 38, 43, 45 and 49 post treatment. Semen was diluted in RSD-1 + TNE and snap frozen in liquid nitrogen. Samples were thawed and assessed by the Sperm Chromatin Structure Assay (SCSA) on the flow cytometer. This measures sperm susceptibility to {\textquoteleft}in situ{\textquoteright} acid denaturation by staining with acridine orange fluorochrome, which fluoresces differentially when binding to double stranded DNA (green) or single stranded DNA (red). The data indicate an increase in the percentage of sperm that have DNA damage, appearing about 21 days post treatment and reaching a maximum at 35 days. The proportion of sperm with moderate to highlevels of DNA damage was significantly (P<0.001) greater in the 48 hour treatment group and was still observed at 49 days while most of the 24 hour treated animals had recovered by this stage. Of particular interest was the shift of the entire sperm population, in DNA fragmentation index (ratio of red fluorescence:total (red + green) fluorescence), indicating increased susceptibility of DNA denaturation in all cells. This was accompanied by an increase in DNA stainability (increase of green fluorescence) which is interpreted asbeing due to an increase in the number of immature sperm cells with less compacted chromatin which results from abnormal or unprocessed protamines. The sperm damage seen after a relatively mild heat treatment indicates possible mechanisms for the adverse effects of modern life styles on male fertility.}, issn = {1176-5283}, author = {McDonald RM and Smith JF and Montgomery GW and Fleming JS and Cox NR} } @conference {41696, title = {Strain differences in Merinos for carcass and meat quality}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {28-31}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {The increased emphasis on the Merino for meat production has heightened the need to quantify the variation across the breed for meat and carcase traits and to produce geneticcorrelations and heritabilities for these traits. This paper reports on strain effects (broad, medium and fine wool) on carcase and meat quality traits for 1934 rams. Rams (~19 months of age) were slaughtered over 4 years and data on animals from 272 sires were collected. Every year, the rams were fed a formulated pellet at pasture for 5 weeks before slaughter. All animals were slaughtered in commercial abattoirs. Hot carcase weights were recorded and the GR measured using a GR knife. After overnight chilling (4{\textendash}5{\textdegree}C), carcases were cut between the 12th/13th ribs and the longissimus thoracis et lumborum (LL) was exposed to the air at chiller temperature for 30 min. Meat colour was measured on the cut surface using a Minolta Chromameter set on the L*, a*, b* system. The pH of the LL and the semitendinosus (ST) muscle was also measured. Fine wool rams were the fattest when compared at the same carcase weight. The broad wool strain had the lowest pH in both muscles and there were minimal differences between strains for meat colour. These real differences between Merino strains in meat quality traits require more detailed investigation in order to understand their biological bases and identify if potential markers exist that could be used in Merino breeding programs.}, issn = {1176-5283}, author = {Hopkins DL and Mortimer SI and Stanley DF and McMillan DC and Anderson SL} } @conference {41964, title = {Summer lamb finishing on forage crops}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {121-125}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {The objective of this study was to compare lamb growth and performance on three forages over summer in a large scale, replicated experiment. The three forage treatments were new spring-sown pasture (cv.Bealey perennial ryegrass and cv.Apex white clover), hybrid leafy turnip (cv.Hunter), and a predominant white clover sward. The study was conducted over 28 days, with 28 days preceding the study as the herbage adjustment period. Entire male lambs (n=270) were allocated to one of the three treatments, balanced for live weight at day -28 (D-28). Live weights and liveweightgains were measured at D-28, -14, 0, 14 and 28. Herbage heights were measured pre- and post-grazing toensure lambs were receiving a herbage allowance of at least three times their potential intake. Herbage quality parameters were also measured post-grazing. Liveweight gains were different (P<0.05) between treatment groups, being 311{\textpm}10.2, 222{\textpm}10.1, and 160{\textpm}10.2 g/day for clover, Hunter, and new pasture, respectively. The results showed that Hunter and clover produced superior lamb growth compared to new pasture over summer for the 28 day trial period.}, issn = {1176-5283}, author = {Lindsay CL and Kemp PD and Kenyon PR and Morris ST} } @conference {41735, title = {Supplemental fumarate has little effect on the detailed composition of bovine milk during early lactation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {242-247}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {Future farming practices need to be assessed by the dairy industry for any impacts they may have on the detailed composition and processability of milk. These impacts may change the milk price a farmer receives and the milk processability,product range and product quality. The use of sodium fumarate (an organic acid) to reduce methane production from dairy cows has previously been reported. This experiment investigated the effect of intra-ruminal infusions of sodium fumarate on the detailed composition of milk from dairy cows. Fumarate (5\% of daily dry matter intake) was infused into 8 lactating cows while 8 cows received infusions of water as a control. Milksamples were collected during a covariate period, then again following a 16-day treatment period, of which cows were housed indoors for the last 9 days. Gross composition of milk and other production parameters have been presented previously. Milk yield, fat and protein were not affected but lactose concentrations were significantly higher in the milk of cows receiving the fumarate. In the current study, none of the individual casein proteinsmeasured showed an effect of treatment. Of the whey proteins examined, concentrations of α-lactalbumin (α-La) were higher (1.07 vs. 0.98 mg/mL; sed 0.038; P < 0.05) and bovine serum albumin (BSA) concentrations were lower (214.6 vs. 251.0 mg/L; sed 15.1; P < 0.05) in the milk of cows receiving fumarate. None of the individual fatty acids or minerals examined showed a treatment effect. The addition of sodium fumarate to the diet of dairy cows in early lactation does not have a major influence on the composition of milk, suggesting that the product could be used with minimal impact on milk composition and product quality at this early stage of lactation.}, issn = {1176-5283}, author = {Turner S-A and Aspin PW and Kolver ES} } @conference {41748, title = {Teat spraying before calving and Streptococcus uberis clinical mastitis in heifers : Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {312-314}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {Mastitis caused by the environmental pathogen Streptococcus uberisis a significant problem for New Zealand dairy farmers. Previous work on teat-spraying heifers three times a week for three weeks prior to calving demonstrated that a decrease in S. uberisteat-end contamination reduced the proportion of quarters infected with S. uberisat calving. This study evaluated the effect of teat-spraying heifers in the dry period for its ability to reduce S. uberisclinical mastitis (CM) after calving. Heifers from five commercial dairy herds (n=343) and one research farm (n=54) were enrolled to the study. Half of the animals from each herd were assigned to a Sprayed and the other half to a Not Sprayed group. Both groups were brought to the dairy three times a week, beginning three weeks prior to predicted calving dates and heifers in the Sprayed group were teat-sprayed with a commercially available iodine-basedteat sanitizer. Cases of CM that occurred in the week after calving were sampled and submitted for bacteriological analysis. Incidence of S. uberisCM was 50\% lower in the Sprayed, affecting 3.6\% heifers vs. 7.4\% heifers of the Not Sprayed group (P=0.085). There was an indication that teat-spraying heifers three weeks prior to calving may have positive benefits in the reduction of CM caused by S. uberisafter calving.}, issn = {1176-5283}, author = {Lopez-Benavides MG and Williamson JH and Lacy-Hulbert SJ} } @conference {41761, title = {Test-day model for national genetic evaluation of milk production traits}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {382-387}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {Genetic evaluation for milk, fat and protein yields, using 270-day lactation yields in an across-breed animal model (AM), has been performed in New Zealand since 1996. A new system has been developed to calculate breeding values from herd-test data. In the current AM, a 270-day lactation yield record is calculated based on 1 to 10 test-day records. The environmental effect of herd-test-day (HTD) is removed during the 270-day lactation yield calculation. However, this is done outside the AM, without reference to the genetic level of the HTD contemporary group. A test-day model (TDM) can simultaneously account for the fixed effects such as HTD contemporary groups,and the genetic, permanent environmental (PE) and temporary environmental randomeffects that affect the trait. By including the effect in the model, the TDM allows the environment specific to each test-day to be better taken into account, resulting in an improved accuracy of evaluation. A TDM can accommodate changes in the genetic and PE effects over time by fitting polynomials of time to these effects. A random regression (RR) TDM can accommodate changes in the genetic and PE effects overtime by fitting Legendre polynomials of days in milk (DIM) to these random effects. The RR TDM allows each cow{\textquoteright}s lactation curve to have a different shape. TDM evaluations are more stable than evaluations obtained using 270-day lactations because they account for genetic differences in maturity rate and persistency of lactation. The sire breeding values (BVs) from the TDM were compared to those from the AM. For sires with more than 30 daughters, the correlations between the BVs from the two models were 0.990, 0.988 and 0.990 for milk, fat and protein yields, respectively. The TDM demonstrated improved stability for sires undergoing their widespread proof. There was less variation in the change in BVs for reproof sires from August through to October compared to the AM. The sires that show the greatest change during early reproof under the AM were sires that were outliers for their TDM persistency breeding values for their breed.}, issn = {1176-5283}, author = {Harris BL and Winkelman AM and Johnson DL and Montgomerie WA} } @conference {42009, title = {Testing glutathione-S-transferase for an association with facial eczema resistance in cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {361-364}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {Resistance to facial eczema (FE) in cattle is known to be a heritable trait. The commonly used indicators of susceptibility in affected groups of animals are gamma glutamyl-transferase (GGT) and glutamate dehydrogenase (GDH), which indicate the severity of the liver injury associated with FE. Published research using mouse models suggests that glutathione-S-transferase (GST) may be a downstream indicator of variation in FE susceptibility, and a study was carried outin calves to test this. Friesian-sired and Jerseysired bull calves were purchased from dairy herds in spring 2004, artificially reared from about four days of age, weaned at 75-80 kg, monitored for base-line GGT activity in blood, and then dosed orally with sporidesmin. At 14 and 21 days after dosing, blood samples were taken to measure the activities of both GDH and GGT. A sample of 45 Friesian calves and 45 Jersey calves from the high and low outliers (using GDH activity within breed, 14 days after dosing) wereblood-sampled 15 or 16 days after dosing and measured for GST activity, with 20-25 animals sampled each day, in balanced groups. There were significant differences in GST activity between high and low GDH groups (P < 0.01), and the pooled within-analysisday regression of GST activity on logGGT activity (day21) was negative (P < 0.05). Results confirmed that low erythrocytic GST activity is an indicator of FEsusceptibility, although the differences seen between resistant and susceptible animals are insufficient for use as a predictive tool.}, issn = {1176-5283}, author = {Morris CA and Cullen NG and Munday R} } @conference {41699, title = {To wether - short scrotum or leave lambs as entire rams ? Revisiting an old question using new genetics}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {44-47}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {A comparison of wethers (WTH), short scrotum (SSC) and rams (RAM) was made on 552 7/16 Romney, 3/16 Poll Dorset, 3/16 Texel and 3/16 East Friesianlambs. Lambs were drafted for slaughter using commercial criteria on weight and condition score at weaning (D81), D120, D154 and D192. Due to faster growth rates, by the end of the 2nd kill (D120) approximately 31\% of RAM and SSC lambs were slaughtered compared with 16\% of WTH lambs (P<0.01), although the difference was no longer significant by the end of the 4 th kill. The carcass weight of WTH (17.6kg) was significantly heavier (P<0.01)than the RAM (17.2kg) but not significantly different to the SSC (17.5kg), despite similar kill liveweights, due to the increased dressing out percentages of the WTH lambs (43.6\%, 43.1\% and 42.5\% respectively; P<0.05). Based on GR, 8.7\% of WTH carcasses graded overfat, compared with only 0.6\% of RAM and SSC carcasses (P<0.001). Over the kill period the price schedule ($/kg carcass weight) dropped, so for the WTH given their longer time to slaughter and poorer grading due to over fat carcasses the price for WTH carcasses ($49.16) was lower (P<0.01) than RAM or SSC carcasses ($50.37 and $50.70). When the added cost of feeding and drenching was taken into consideration, the net value of the WTH was evenless. Composite wether lambs of still potentially present an opportunity cost, except incertain situations where the management benefits outweigh the direct financial cost. }, issn = {1176-5283}, author = {PL Johnson and Kenyon PR and Burnham DL and West DM} } @conference {41979, title = {Ultrasonic measurement of backfat and muscling in sheep selected for parasite-related traits}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {198-203}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {This paper reports on backfat depth and muscling comparisons of sheep selected for nematode parasiterelated traits. Results are from two AgResearch projects, the first located at Kaitoke Farm (Upper Hutt), in which experimental Romney lines wereselectively bred for susceptibility (S) or resistance (R) to nematode infection (high or low faecal egg count), or for resilience to nematode challenge whilst maintaining acceptable growth with minimal anthelmintic treatment (RL line); these lines grazed alongside an unselected control line (C). The second project was located at Ballantrae (Northern Wairarapa), in which Romney breeding lines were selected for resilience, with two replicate farmlets under {\textquoteright}Conventional{\textquoteright} parasite management (with anthelmintic treatment), and with two further replicate farmlets under {\textquoteright}Low-Chemical{\textquoteright} management. The four replicate lines at Ballantrae were serviced by rams of equivalent genetics, from elite RL-line sires bred at Kaitoke or Ballantrae. Ultrasonic backfat depth and eye muscle dimensions (length, depth and area) of ewe lambs from each project were assessed at 8-9 months of age (234 C-, S-, R- and RLline lambs born in 2003 at Kaitoke, and 154 resilient lambs born in 2004 at Ballantrae). Adjustments were made for significant fixed effects including covariate adjustment for live weight. No significant differences were found among the R, C and RL lines for either trait, but the S line had 5-10\% smaller eye-muscle dimensions (P < 0.05) than the other lines following an extended period of natural nematode challenge with minimal drench treatment. The two replicate lines under Low-Chemical management were 3.8 {\textpm} 0.6 kg (11.8\%) lighter in May than the replicates under Conventional management (P < 0.001). After adjustment for live weight, lambs in the Conventional treatments had 15\% larger eye-muscle areas (P < 0.001) but not backfat depths than those in the Low-Chemical treatments. Results suggest that muscle dimensions of the Sline lambs were more affected than those of their R-line counterparts by parasite infection, whilst the C-, R- and RL-line lambs did not differ significantly. At Ballantrae, even at equivalent live weights, the two Conventional replicates had more muscling but not fat depth than the two Low-Chemical replicates.}, issn = {1176-5283}, author = {Wheeler M and Morris CA and Bisset SA and Vlassoff A and Mackay AD and West CJ and Devantier BP} } @conference {41974, title = {Uptake of DNA testing by the livestock industries of New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {168-174}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {This paper describes, from the perspective of the main animal genotyping service laboratory, the uptake of DNA tests by the New Zealand livestock industries. We describe a rapid increase in the use of DNA testing over the last 3-4 years in New Zealand. In particular pedigree establishment and verification has shown significant uptake by deer, cattle and sheep breeders. The highest penetration of DNA testing has been in the deer industry where we estimate 30-40\% of the recorded breeding population uses DNA testing to establish and verify pedigrees. The increases have mainly been due to an increase in the number of samples per client rather than an increase in the number of clients using the service.}, issn = {1176-5283}, author = {Crawford AM and Anderson RM and McEwan KM} } @conference {41733, title = {The use of diazepam as a pharmacological method for evaluating anxiety in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {232-236}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {The aim of this study was to examine the effects of diazepam, an anti-anxiety drug, on the fear responses of sheep and its usefulness as a pharmacological method to study welfare. Fourteen, eight month old Romney ewes were randomly assigned to two treatments and injected via jugular venepuncture with diazepam (0.37mg/kg) or saline (controls) 20 minutes before exposure to a barking dog. Heart rate (bpm) and escape attempts were recorded throughout a 10 minute period before injection (baseline), 20 minutes post injection and 15 minutes following the dog. Average heart rate was lower in diazepam-treated sheep during the first 5 minutes following injection (P<0.01) and was significantly higher (P<0.01) for both diazepam and saline-treated sheep during the 5 minutes following exposure to the dog compared to baseline (+23.1 and +21.5 bpm for diazepam and saline respectively). Heart rate then decreased back to baseline levels during the last 10 minutes. Diazepam-treated sheep tended to have a higher number of escape attempts during the 5 minutes following exposure to the dog (P=0.08) compared to controls, suggesting that diazepam may have paradoxically increased anxiety in some sheep. The lack of differences between treatments suggests that diazepam did not modify the fear response of sheep to a dog. There appear to be interpretive difficulties associated with dose rates and the appropriate fear model in the use of diazepam to study anxiety in sheep.}, issn = {1176-5283}, author = {Stewart M and Webster JR and Dowling SK and Stafford KJ and Huddart FJ} } @conference {41730, title = {The use of neural networks to detect minor and major pathogens that cause bovine mastitis}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {215-219}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {Bovine mastitis is caused by a diverse range of bacteria, broadly categorised as major or minor pathogens. The objective of this research was to develop an unsupervised neural network (USNN) model for detecting major and minor bacterial pathogens present in milk, based on changes in milk parameters associated with mastitis. A database of 4852 quarter milk samples with records for milk parameters and bacteriological status was used to train and validate the USNN model. Correlations (P<0.05) were found between the infection status of a quarter and its somatic cell score (SCS, 0.86), electrical resistance index (ERI, -0.59) and protein percentage (PP, 0.33). Due to significant multicolinearity, the original variables were decorrelated using principle component analysis. Sensitivity of the model for correctly detecting major and minor infections was 80\% and 89\%, respectively. Specificity of the model for correctly detecting non-infected cases was 97\%. The model is able to differentiate infected milk from non-infected based on milk parameters associated with mastitis. It is concluded that the USNN model can be developed and incorporated into milking machines to provide a reliable basis for mastitis control.}, issn = {1176-5283}, author = {Hassan KJ and Samarasinghe S and Lopez-Benavides MG} } @conference {41967, title = {Validation of a technology for objectively measuring behaviour in dairy cows and its application for oestrous detection}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {136-142}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {Devices (IceTag{\textregistered}ActivityMonitor) using accelerometer technology to determine the behaviour of cows (proportion of time lying, standing, active and step count) were attached to 15 cows (2 per cow) and validated between devices and against observed behaviour. For standing and active, 95\% of paired (within cow) one minute data points were within 7\% points, 95\% of the lying data points were within 1\% point, and 95\% of stepping data were within 3 steps. The device recorded 100\% of lying bouts within {\textpm}1 minute of visually observed data. In a second experiment, 16 lactating dairy cows were fitted with IceTag{\textregistered}s and the relationship between behaviour profiles and oestrus evaluated. Blood progesterone concentration and twicedaily visual observations were used to identify precisely ovulation events and four algorithms, based on active and lying behaviour, were developed. A 24 hour rolling mean of activity and a slope threshold of 0.2 calculated for either the previous 10 hours (Activity24/10) or 5 hours (Activity24/5) correctly identified 93\% of oestrous events, with 21\% and 18\% false positive alerts, respectively. Two further algorithms, Lying<20\% or Active>5.5\% between midnight and 05:00hrs identified 50\% and 64\% of oestrous events, with 36\% and 18\% false positive alerts, respectively. In a third experiment using 30 cows, 56 oestrous events were identified through milk progesterone profiles and visual observation. Algorithm Activity24/10 and Activity24/5 identified 84\% and 76\% of oestrous events respectively. The IceTag{\textregistered}accurately recorded several types of cattle behaviour suggesting useful applications as both a research and industry tool.}, issn = {1176-5283}, author = {McGowan JE and Burke CR and Jago JG} } @conference {42007, title = {Variation of fibre characteristics important in processing, over the body of Australian brushtail possum ( Trichosurus vulpecula )}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {351-355}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {The amounts of fur and processing properties of fur from the Australian Brushtail Possum (Trichosurus vulpecula) were determined. The amounts of fur per animal ranged from 18 {\textendash} 94 g depending on the sizes of the animals, with 75\% coming from the body, 10 - 151\% from each of the belly and tail. Fur from the belly was shorter and finer than that from the body, which was shorter and finer than that from the tail (20.1 vs. 27.1 vs. 37.9 mm; 16.2 vs. 17.7 vs. 22.9 {\textmu}m respectively (P < 0.001). Belly fur was less curved than body or tail fur (47.2 vs. 52.8 and 55.6 {\textdegree}/mm respectively (P < 0.001)). The fibre curvature of fur from all three body sites was half to two thirds of the curvature expected for Merino wool of similar diameter. Coefficients of variation of both fibre length and fibre diameter were approximately double those normally observed in Merino wool (coefficient of variation (CV) = 32.8\% (length) and 47.6\% (diameter)). The number of medullated fibres was high (mean = 44.5\% by weight), with most of the coarser fibres being medullated. The cuticle scale structure was smoother than Merino wool. The high degree of medullation observed contributes to the reported high insulation value of the fur as it results in a high number of fibres for the weight. The relatively low curvature and low scale profile, give the fibre a smooth, slippery surface. This makes processing difficult and causes problems for fibre retention in fabric.}, issn = {1176-5283}, author = {Reid TC and Causer SM and Urquhart RA and Woods JL} } @conference {42005, title = {Variation of wool characteristics across the body of New Zealand Wiltshire sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {339-344}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {Variations in wool quality within a sheep arise from inherent differences between sites across the body and between fibres within a site, as well as variationsalong individual fibres that result from nutritional, reproductive and seasonal influences. The Wiltshire sheep is a shedding breed in which there is renewed interest due to the relative values of meat and wool, and the costs of wool production. Staple length, fibre diameter, fibre diameter standard deviation, and medullation were measured on wool grown at seventeen sites across the body of two-tooth Wiltshire rams undergoing a photoperiod-induced wool growth cycle. Staple length was longest on the shoulder (41 {\textpm} 2.5 mm) and shortest on the belly (14 {\textpm} 1.2 mm). There was an inverse correlation between staple length and fibre diameter with the finest fibres on the shoulder and coarsest on the hip (R{\texttwosuperior}=-0.7, P<0.001). This gradient of increasing fibre diameter was associated with increased variation within-staples (R{\texttwosuperior}=-0.8, P<0.001). Fibre medullation increased from the shoulder to the hip. Short coarse fibres on the front and back legs, along with facial hairs highlight differences in major regional skin domains that are established in utero. Although midside samples were representative for each fleece they did not portray the anterior/posterior and dorsal/ventral gradients observed in all characteristics studied. Understanding the within-fleece variation in wool characteristics is a requirement for producing sheep with more desirable fleece distribution patterns.}, issn = {1176-5283}, author = {Craven AJ and Ashby MG and Scobie DR and Nixon AJ} } @conference {41616, title = {Apparent digestibility and rumen fermentation of fresh plantain (Plantago lanceolata cv Ceres Tonic) and perennial ryegrass (Lolium perenne cv Nui) - based pasture fed to red deer (Cervus elaphus)}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {64-69}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {The aim of this study was to compare the apparent digestibility and rumen fermentation products in deer fed plantain (Plantago lanceolata) and perennial ryegrass-based pasture (Lolium perenne) during spring. Forages were cut and fed fresh in a cross-over design to seven castrated, rumen fistulated red deer (Cervus elaphus) housed individually indoors in metabolism crates. Plantain contained greater levels of organic matter and lignin and had a greater ratio of readily fermentable to structural carbohydrates and lower levels of crude protein (P < 0.01), compared with ryegrass-based pasture. The apparent digestibility of organic matter for both forages was high, but less for plantain (74.9\%) compared with ryegrass-based pasture (81.5\%) (P < 0.01). The ammonia concentration of rumen fluid from deer fed plantain (4.6 mmol/L) was less compared with fluid from deer fed ryegrass-based pasture (20.9 mmol/L) (P < 0.01). The apparent reduction in degradation of protein to ammonia in the rumen of deer fed plantain may have implications for increasing the efficiency of use of dietary protein in grazing ruminants. Further research is required to investigate the effect of feeding plantain, and its secondary compounds, on the rumen microbial ecosystem and rumen fermentation. }, issn = {1176-5283}, author = {Swainson NM and Hoskin SO} } @conference {41932, title = {Artificial rearing of lambs - avoiding abomasal bloat}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {386-389}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {Triplets occur when lambing percentages exceed 130\%. When triplets are left with their dam, survival is often less than 75\%. Artificial rearing of one lamb from each set of triplets offers the chance to increase survival rates. But experience to date has frequently resulted in death rates of 10\% to 30\% of lambs. On the author{\textquoteright}s farm about 100 sets of triplets are born each year. In 2002 an artificial rearing system was put in place based on the Poukawa system. The smallest triplet from each set was removed for artificial rearing. In 2002 and 2003, when lambs were 3 to 5 weeks old, up to 25\% died. A worldwide information search suggested that the disorder was possibly abomasal bloat. A Norwegian method of preparing "soured" milk replacer that had been demonstrated to limit abomasal bloat was adapted for New Zealand conditions. Lambs are fed cow colostrum for two days, followed by ad lib. cold "soured" whole milk replacer and ad lib. meal. In 2004 and 2005, there have been no deaths due to abomasal bloat. Total deaths from 199 lambs have been 9. Live weight gains of the lambs have been 220-250 grams per day till 8 weeks. }, issn = {1176-5283}, author = {Bull C and Binnie B} } @conference {41628, title = {The biological basis of variation in sheep{\textquoteright}s fleece cover}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {124-129}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {Selective breeding has been used for thousands of years to improve the quality and weight of wool, but surprisingly there is still a large amount of geneticvariation present at the loci involved in the {\textquotedblleft}blueprint{\textquotedblright} for wool synthesis. This genetic heterogeneity results in considerable variation within, and between individual fleeces. This has both positive and negative implications. Where a wool processor requires uniformity in raw stock, both to gain efficiency in processing and to make a product to specification, it has a negative effect. Where specific traits convey unique properties it opens up opportunities for differentiated products. Markers for genes or knowledge of individual gene effects may be useful for identifying sheep with desirable wool traits that are difficult or expensive to measure under field conditions. The discovery of genetic variation in valuable fibre traits could allow the development of gene-marker tests which would assist breeding for more consistent wool.}, issn = {1176-5283}, author = {Scobie DR and Nixon AJ and Rufaut NW} } @conference {41875, title = {Body condition score as a candidate trait in the breeding worth dairy index}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {103-106}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {Body condition score (BCS) has been proposed for inclusion in the New Zealand national dairy index, Breeding Worth (BW), to account for replenishment of body tissue. Currently, the breeding objectives model positively accounts for body tissue mobilisation (through extra yield), but not the negative cost of replenishing body tissue. Two methods have been proposed: 1) Including BCS directly into BW by calculating and assigning an economic value to BCS and 2) Adjusting liveweight Breeding Values (BVs) for BCS, which would mean that liveweight BVs would be expressed at a constant BCS (indirect method). Energy equations were used to calculate the direct economic value for BCS and included a sensitivity analysis. With an economic weight of $25, the percentage emphasis of BCS in BW would be 3.4\%. Including BCS in BW, either directly or indirectly, had little impact on sire rankings (rank correlations with and without BCS within breed were >0.99) and would only have a small impact on the economic response of BW ($0.02 net /cow/annum) and the improvement in BCS (0.006 BCS units/cow/annum). It is concluded that there would be little benefit to including BCS as an independent trait in BW. Body condition score is already included as a predictor in the genetic evaluation of fertility and breeding values for BCS will be estimated routinely from the fertility model.}, issn = {1176-5283}, author = {Pryce JE and Harris BL and Johnson DL and Montgomerie WA} } @conference {41887, title = {Bovine viral diarrhoea virus in dairy cattle in New Zealand - studies on its prevalence, biologic and economic impact}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {162-167}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {The majority (>90\%) of dairy cattle will conceive following insemination or natural service, but only about 55\% of cattle calve to any single mating. The majority of losses occur before the time of pregnancy recognition and such cattle are generally detected in oestrus and rebred. However, losses do occur after the period of pregnancy recognition resulting in prolonged duration of open periods and increased probability of culling for infertility. Reasons for loss include genetic abnormalities, infectious agents such as Neospora caninum, bovine viral diarrhoea virus (BVDV), and plant toxicities. The incidence, causes and economic impact of pregnancy loss are poorly defined in New Zealand. In a survey of bulk tank milk, 93\% of 141 dairy herds had >10\% of cows with BVDV antibody. In another study, 602 herds with a high vs. low bulk tank milk (BTM) BVDV antibody concentration were associated with 1.7\% higher annual abortion rates, 2.9d longer calving to conception intervals, 0.04 more services/conception, and 1kg/d reduced solid corrected milk production. Losses due to BVDV were assessed as $90/cow/year in affected herds. It is concluded that pregnancy loss imposes significant economic costs on the New Zealand dairy industry and that BVDV is likely to be major contributing causative agent. Further research is required to evaluate the effects of BVDV on reproduction in dairy herds, the risk factors for the disease and the cost:benefit of control or eradication strategies. }, issn = {1176-5283}, author = {Compton CWR and McDougall S and Heuer C} } @conference {41674, title = {Chevre meat{\textquoteright} (goat meat) impressions and taste responses by Japanese}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {360-362}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {To investigate the strong prejudice against goat meat and to assist with promoting goat meat consumption in Japan, a taste-test survey and two questionnaire surveys were carried out amongst 30 university students. A pre-questionnaire survey was undertaken before the goat meat was tasted to understand the first impressions of the meat. Three different goat meat dishes (simmered meat and potatoes, goat casserole and sweet and sour goat) were served for taste evaluation. The results from this survey suggested that goat meat should be rebranded before embarking on a promotional campaign in Japan. "Chevre meat" has been chosen as a new term to promote goat meat. The phonological phrase "goat" in Japanese is not appealing to the Japanese consumer. Instead of using the Japanese word for goat, "chevre" (which in French means goat) is suitable for promotion. Combining the French and English words together as "chevre meat" sounds attractive to the Japanese consumer. Attaching an attractive recipe card to the chevre meat package will help consumers to understand how to prepare goat meat. Based on these results, a New Zealand exporter has undertaken to ship a New Zealand goat meat sample to Japan beginning in late 2005. }, issn = {1176-5283}, author = {Ozawa T and Nishitani J and Blair HT} } @conference {41864, title = {Clover-rich diets and production, behaviour and nutrient use by cows in late lactation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {42-49}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {The nutritional value of legumes for high milk production is seldom captured because grazed dairy pastures in NZ typically contain insufficient legume to satisfy the cows{\textquoteright} requirements. This paper reports interim results from a project investigating novel methods of forage presentation to cows, to enhance the contribution of legume to their diet. Four groups of spring-calving cows (n=5) in late-lactation were allocated to four treatments in a balanced, cross-over design. Two treatments consisted of spatial and temporal arrangements of grass and white clover allocated to cows as follows: i) continuous free access to grass and white clover growing separately as side-by-side monocultures (G/C) and ii) grass-only at {\textquoteleft}night{\textquoteleft} between the afternoon and morning milking and clover-only during the {\textquoteleft}day{\textquoteleft} between morning and afternoon milking (GnCd). These were compared against controls of iii) a typical mixed ryegrass-white clover pasture (Mix; an industry standard) and iv) a ryegrass-only pasture (Grass; a forage standard). Cows grazed each treatment for 8 days before moving to the next treatment in the pre-determined sequence. Measurements included milk production and composition, the time spent grazing during the day and the night (separately for grass and white clover in G/C) and the concentrations in the milk of skatole and indole, as metabolic indicators of nutrient acquisition and utilisation in the contrasting forage treatments. Cows offered G/C or GnCd produced 19.4 and 17.9 kg milk/cow/day, respectively, compared with 15.0 and 14.6 kg/cow/day when offered Mix or Grass, respectively (P=0.01, SEM=0.74). The diurnal distribution of grazing was influenced by pasture treatment (treatment x time interaction P <0.001). Cows on G/C grazed proportionately more at {\textquoteleft}night{\textquoteright} and cows on GnCd proportionately less at {\textquoteleft}night{\textquoteright} compared with Grass or Mix. GnCd constrained the cows to spend less time grazing clover than those offered G/C (245 vs. 408 mins grazing clover during 24 hrs) and more time grazing grass (253 vs. 105 mins in 24 hrs). The apparent {\textquoteleft}restriction{\textquoteleft} in GnCd to grazing clover-only during the day did not significantly reduce milk yield compared with G/C. The spatial and temporal allocations of grass and clover affected the concentrations of indolic compounds in PM and AM milk, suggesting there is scope to improve the efficiency of protein utilisation in the rumen. }, issn = {1176-5283}, author = {Cosgrove GP and Burke JL and Death AF and Lane GA and Fraser K and Pacheco D and Parsons AJ} } @conference {41912, title = {A comparison of sites for monitoring body temperature of cattle and sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {290-294}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {Four experiments were carried out to investigate whether temperature measurements recorded continuously from the vagina of ruminant animals are comparable to those measured at the rectum. Normal vaginal, rectal and ruminal temperatures of sheep (n = 4) and cattle (n = 2) were measured twice for 4 h and 2.5 h, respectively. Fever was induced by administration of endotoxin to sheep (0.8 {\textmu}g/kg live weight, n = 4) and cattle (0.2 {\textmu}g/kg live weight, n = 2) and the temperatures were recorded for 4 h. Normal vaginal and rectal temperatures were recorded simultaneously in 8 sheep for 2 h and separately in 6 and 12 sheep, respectively, for 4 h. In sheep, mean ({\textpm} SEM) rectal temperature ranged between 39.1 {\textdegree}C and 39.4 {\textdegree}C ({\textpm} up to 0.11 {\textdegree}C) and mean vaginal temperature ranged between 39.2 {\textdegree}C and 39.5 {\textdegree}C ({\textpm} up to 0.17 {\textdegree}C). In cattle, means ({\textpm} SEM) of rectal and vaginal temperatures were both 38.6 {\textpm} 0.10 {\textdegree}C. Endotoxin elevated temperatures by about 2 {\textdegree}C and ruminal temperature was occasionally up to 1 {\textdegree}C higher than rectal or vaginal temperature. Rectal and vaginal temperatures did not differ significantly from each other in either species. The findings indicate that, for monitoring the internal thermal environment of cattle and sheep, vaginal temperature is equivalent to rectal temperature and support other evidence that temperature of the rumen can be independent of body temperature. }, issn = {1176-5283}, author = {Smaill AL and Barrell GK} } @conference {41886, title = {Concluding Remarks : Genomics and the future of wool production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {154-155}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {Oil supplements can be used in dairy rations to increase dietary energy density (and energy intake) and reduce methane (CH4) emissions from rumen fermentation. Trials at Dexcel measured effects of oil supplementation on dry matter intake (DMI), milk yield and methane production after lactating dairy cows were fed pasture-based diets for short (14-day) and long (12-week) periods. In the short-term trial, 32 cows received either no oil or three mixtures of sunflower and fish oil at 500g/d. In the long-term trial 20 cows grazed pasture and received either no oil or 300g linseed and fish oil for 11 weeks prior to methane measurements. The type of oil in the short-term trial did not affect methane production and oils had no effect on DMI or milk yield but reduced total methane emissions by 27\% (176 vs. 242g CH4/cow/d, sed=10.6) and CH4/kg DM (13.5 vs. 18.5g CH4/kg DM, sed=0.88). In the long-term trial, oil had no effect on methane emissions (353 (oil) vs. 323g CH4/cow/d (control), sed=17.0 and 21.7 vs. 23.0g CH4/kg DM, sed=1.01). These trials did not show benefits of oils for milk production and emphasize the need for longterm studies when developing on-farm strategies for methane mitigation.}, issn = {1176-5283}, author = {Nixon AJ} } @conference {41606, title = {Contract Introduction : The problem of anthelmintic resistance}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {14}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {S{\textthreesuperior} was initiated in November 2004 by a small number of industry individuals and a group of elite merino and mid micron breeders and will run until November 2007. It is a project that brings together two sectors of the sheep breeding industry that views the sustainable management of parasites critical to their and their commercial client{\textquoteright}s futures. The project aims to examine the issue of sustainable parasite management via a number of approaches and not to focus on a single element of parasite management. Key elements addressed include the synergy between sustainable parasite management, breeding for resistance and property bio-security, to enhance farming operations.}, issn = {1176-5283}, author = {Hoskin SO} } @conference {41611, title = {Development of a model to predict pasture intake for grazing dairy cows in Argentina}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {35-41}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {The nutritional value of legumes for high milk production is seldom captured because grazed dairy pastures in NZ typically contain insufficient legume tosatisfy the cows{\textquoteright} requirements. This paper reports interim results from a project investigating novel methods of forage presentation to cows, to enhance the contribution of legume to their diet. Four groups ofspring-calving cows (n=5) in late-lactation were allocated to four treatments in a balanced, cross-over design. Two treatments consisted of spatial and temporal arrangements of grass and white clover allocatedto cows as follows: i) continuous free access to grass and white clover growing separately as side-by-sidemonocultures (G/C) and ii) grass-only at {\textquoteright}night{\textquoteright} between the afternoon and morning milking and clover-only during the {\textquoteright}day{\textquoteright} between morning and afternoon milking (GnCd). These were compared against controlsof iii) a typical mixed ryegrass-white clover pasture (Mix; an industry standard) and iv) a ryegrass-only pasture (Grass; a forage standard). Cows grazed each treatment for 8 days before moving to the next treatment in the pre-determined sequence. Measurements included milk production and composition, the time spent grazing during the day and the night (separately for grass and white clover in G/C) and the concentrations in the milk of skatole and indole, as metabolic indicators of nutrient acquisition and utilisation in the contrasting forage treatments. Cows offered G/C or GnCd produced 19.4 and 17.9 kg milk/cow/day, respectively, compared with 15.0 and 14.6 kg/cow/day when offered Mix or Grass, respectively (P=0.01, SEM=0.74). The diurnal distribution of grazing was influenced by pasture treatment (treatment x time interaction P <0.001). Cows on G/C grazed proportionately more at {\textquoteleft}night{\textquoteright} and cows on GnCd proportionately less at {\textquoteleft}night{\textquoteright} compared with Grass or Mix. GnCd constrained the cows to spend less time grazing clover than those offered G/C (245 vs. 408 mins grazing clover during 24 hrs) and more time grazing grass (253 vs. 105 mins in 24 hrs). The apparent {\textquoteright}restriction{\textquoteright} in GnCd to grazing clover-only during the day did not significantly reduce milk yield compared with G/C. The spatial and temporal allocations of grass and clover affected the concentrations of indolic compounds in PM and AM milk, suggesting there is scope to improve the efficiency of protein utilisation in the rumen.}, issn = {1176-5283}, author = {Baudracco J and Lopez-Villalobos N and Holmes CW and Brookes IM and Kemp P and Comeron E and Romero LA and Horan B and Dillon P and Berry D} } @conference {41866, title = {Development of a {\textquoteright}Wapiti Score{\textquoteright} visual assessment tool for determining introgression of Wapiti genes in young red deer}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {55-58}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {Red deer are the predominant farmed breed type in New Zealand, but crossbreeding red females with wapiti (or elk) males in a terminal sire system is common. Introgression of wapiti genes into the national red deer breeding hind herd has been shown to have a negative impact on the pregnancy rate of 16-18 month old hinds. We devised a four point visual scoring system ({\textquoteleft}Wapiti Score{\textquoteright}), based on wapiti phenotype characteristics, for application to weaner (6-10 month old) red deer, to allow rapid detection of wapiti introgression. This scoring system was trialled and refined using 449 rising-one-year-old red deer of mixed genotype and sex on a commercial breeding and finishing farm, during three pelage phases. For a subset of 186 animals {\textquoteleft}Wapiti Score{\textquoteright} was compared to the DNA based GenomnzTM GenometerTM G3 Hybrid Test {\textquoteleft}Estimated Elk{\textquoteright} (EstElk), where EstElk; is the estimated proportion of wapiti (elk) genes in an individual animal predicted by the GenometerTM. A significant positive correlation (P < 0.05) was found between EstElk and {\textquoteleft}Wapiti Score{\textquoteright} for two independent observers, with an increase of one point in {\textquoteleft}Wapiti Score{\textquoteright} corresponding to an increase of approximately 0.10 in EstElk. The strongest correlation between Wapiti Score and EstElk were from the winter and spring scores. The effectiveness of Wapiti Score as a tool for classifying young deer by breed-type (red deer or wapiti ) was assessed using 0.2 EstElk as the breed-type threshold and comparing that against different selection Wapiti Scores (1-3). }, issn = {1176-5283}, author = {Ward JF and Scott IC and Asher GW and Littlejohn RP} } @conference {41876, title = {Development of new fertility breeding values in the dairy industry}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {107-112}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {This paper provides the basis for a new method for calculating fertility breeding values. The objective of this study was to: firstly, investigate the data extract of mating and calving records from Livestock Improvement{\textquoteleft}s national database to identify improvements, secondly investigate the definition of the fertility trait from percent of calves born from artificial insemination (AI) to 42 day calving rate, and thirdly explore the inclusion of milk production and body condition score information. The overall aim was to improve the accuracy of the fertility breeding values available when a sire{\textquoteleft}s daughters have completed their first lactation (i.e., the time of the sire{\textquoteleft}s first proof). A new procedure for routine national evaluation of these traits is outlined. Results from the new system are given. Possible future enhancements to the new system are discussed. The new method improves the accuracy of the fertility breeding value for first crop sires with 80 daughters from 45\% to 52\%. The inclusion of body condition score and milk production in the calculation of the fertility breeding value improves the response to selection for fertility within breeding worth index by 34\% per annum. The improvement in response to selection is worth 0.18 $/cow/year or approximately $700,000 annually to the dairy industry. }, issn = {1176-5283}, author = {Harris BL and Pryce JE and Xu ZZ and Montgomerie WA} } @conference {41670, title = {Diet or strain: Effects on postpartum anovulatory interval in dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {339-343}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {Changes in cow genetics and systems of farming have had large effects on the reproductive performance of dairy cows. The objective of this study was to determine if grain supplementation modified the previously identified effects of Holstein-Friesian (HF) strain on the postpartum anoestrus interval (PPAI). Thirty multiparous Overseas (OS) HF and 30 New Zealand-HF cows from a 1990s strain (NZ) were offered unrestricted access to fresh pasture and randomly allocated to three levels of a maize and barley-based concentrate supplementation (0, 3 or 6 kg DM/day). Postpartum anovulatory interval (PPAI) was not significantly affected by either strain or diet, and there was no significant strain x diet interaction. Results suggest that the nutritional requirements necessary for multiparous NZ or OS HF cows to resume oestrous cycles before 40 days postpartum can be achieved when offered unrestricted access to high quality pasture. In this circumstance, additional concentrate feeding did not alter the length of the postpartum anoestrous interval. }, issn = {1176-5283}, author = {Chagas LM and Gore PJS and Sheahan AJ and Lee JM and Watkins KA and Aspin PW and Roche JR} } @conference {41942, title = {Do ewes with twin and triplet lambs produce different yields of milk and does the grazing behaviour of their lambs differ?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {444-449}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {This trial was designed to determine if ewes with triplets produce more milk than those with twins, and, if not, do triplet lambs compensate by extra grazing. Milk yield (MY) of ewes with twin (n=13) and triplet (n=8) lambs, grazing pasture in spring was measured four, seven and ten weeks postpartum. Ewes and lambs were separated in the morning and MY was measured by the oxytocin method. MY did not differ in ewes with triplets (2525 {\textpm} 243 g/d) from that in ewes with twins (2204 {\textpm} 149 g/d) at week four, week seven (1847 {\textpm} 238 versus 1684 {\textpm} 111 g/d), or at week ten (1448 {\textpm} 139 versus 1264 {\textpm} 85 g/d). NIRS analyses showed no significant consistent difference in fat (triplet: twin 7.7: 7.5 {\textpm} 0.4\%), protein (4.4: 4.3 {\textpm} 0.2\%), lactose (4.71: 4.72 {\textpm} 0.03\%) and total solids (17.48: 17.36 {\textpm} 0.35\%) composition of milk from ewes with triplet or twin lambs (data are means of all samples). Mammary gland dimension B, the distance across the gland next to the teats, was better correlated (R2 0.31, P<0.05) with MY than other dimensions tested. Behaviour observations (whether the lamb was grazing or suckling) were made weekly 3-9 weeks postpartum. The time spent grazing by triplets (39.4 {\textpm} 1.94 \% on lactation day 29) was significantly greater (P<0.05) than the time spent grazing by twins (37.7 {\textpm} 1.94\% on lactation day 29) on three observation days and, overall, triplet lambs spent more time grazing than twin lambs. Birth weight of twin lambs (4.39 {\textpm} 0.14 kg) was not significantly greater than that of triplets (4.00 {\textpm} 0.20 kg), but they grew significantly faster (P<0.05) from week four till week ten, gaining 17.0 kg compared to 14.9 kg for triplets. Triplets suffer a relative lack of available milk nutrients compared to twins and are not able to completely compensate for this by increasing grazing time. }, issn = {1176-5283}, author = {Peterson SW and Kenyon PR and Morris ST} } @conference {41675, title = {Eating quality of commercial meat cuts from Australian lambs and sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {363-367}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {Triplets occur when lambing percentages exceed 130\%. When triplets are left with their dam, survival is often less than 75\%. Artificial rearing of onelamb from each set of triplets offers the chance to increase survival rates. But experience to date has frequently resulted in death rates of10\% to 30\% of lambs. On the author{\textquoteright}s farm about 100 sets of triplets are born each year. In 2002 an artificial rearing system was put in place based on the Poukawa system. The smallesttriplet from each set was removed for artificial rearing. In 2002 and 2003, when lambs were 3 to 5 weeks old, up to 25\% died. A worldwide information search suggested that the disorder was possibly abomasal bloat. A Norwegian method of preparing {\textquotedblleft}soured{\textquotedblright} milk replacer that had been demonstrated to limit abomasal bloat was adapted for New Zealand conditions. Lambs are fed cow colostrum for two days, followed by ad lib. cold {\textquotedblleft}soured{\textquotedblright} whole milk replacer and ad lib. meal. In 2004 and 2005, there have been no deaths due to abomasal bloat. Total deaths from 199 lambs have been 9. Live weight gains of the lambs have been 220-250 grams per day till 8 weeks.}, issn = {1176-5283}, author = {Pethick DW and Pleasants AB and Gee AM and Hopkins DL and Ross IR} } @conference {41885, title = {Economic consequences for sheep farmers from using genetic technologies}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {149-154}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {Agricultural commodity products experience marked price trends over time. In the 1980s the balance between returns to growers, before deducting costs, from meat and wool was 46/54. The ratio has now shifted to 83/17. Price increases of the magnitude currently required to redress this imbalance for wool growers may be achievable through genomic technologies. Such technologies could create a demand for biological components extractable from a proportion of the national clip, permit the development of novel fibre types and significantly reduce wool harvesting and husbandry costs. The economic benefits to sheep owners through changing wool characteristics such as fibre diameter or crimp are limited by existing high volume, low profit margin value chains. New technologies which improve wool characteristics and value should be complemented where possible by direct supply relationships between producers and end-users in order to justify their development and to sustain price premiums.}, issn = {1176-5283}, author = {Sumner RMW and Davison RM} } @conference {41655, title = {An economic evaluation of automatic milking systems for New Zealand dairy farms}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {263-269}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {An economic analysis for automatic milking for a medium sized farm set up to milk 450 cows and installing either a 40-bail rotary dairy with automated cup removal and drafting or a 5-unit Greenfield system is evaluated. The analysis used a model that incorporated findings from the previous 5 years of research and development at the Greenfield automatic milking project and used physical and financial data collected in Dexcel{\textquoteright}s 2003/04 Economic Farm Survey for the conventional milking system comparison. The model assumed a payout of $4.25/kg milk solids (MS) and used current cost of technology. Once cows were established into the Greenfield System, the cost of producing 1 kg MS was 27\% higher than for the conventional rotary system. This was due to higher interest, depreciation and service contract costs, despite the lower labour, cow health and dairy costs. Sensitivity analysis showed that when other factors were held constant a 70\% decrease in capital cost or a more than two-fold increase in cow throughput was required for the Greenfield System to be as economic as the rotary system. Alternatively combining future improvements in AMS technology and farm system development including improved throughput to 112 cows/AMS, a 25\% decrease in milk harvesting system capital cost, equivalent production and a 10\% increase in the cost of labour produce a similar economic performance for the two systems. }, issn = {1176-5283}, author = {Jago JG and Davis KL and Newman M and Woolford MW} } @conference {41903, title = {Effect of an extended milking interval on recovery of milk yield and somatic cell count in dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {241-244}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {The objective of the study was to determine whether lactation could be re-initiated after several days without milking. Thirty-six cows in mid lactation were subjected to a single period without milking of either 2, 4 or 7 days. Following these periods twice daily milking resumed. Two days after resumption of twice daily milking, milk yield was depressed to 92, 80 and 51\% of pre-treatment (twice a day milking) rates in the 2, 4 and 7-day treatments. The 2- and 4-d treatments achieved pre-treatment milk yields 3 and 4 days after the resumption of milking, respectively. The 7-d treatment failed to achieve pre-treatment yields in this time period. However, 6 days after the resumption of twice-daily milking there was no difference in average milk yield between the 3 groups. Following the resumption of milking, SCC exceeded 2 million cells/ml for the first day in all treatments. Within 3 days the SCC for the 2 and 4-day treatments were below the 400, 000 cells/ml penalty threshold. However, it took five days milking to achieve this level for the 7-day treatment. The results indicate that successful lactations can be re-established after up to 7 days without milking in mid-lactation, with minimal carry-over effects on milk yield for the rest of the lactation. }, issn = {1176-5283}, author = {Dalley DE and Davis SR} } @conference {41679, title = {The effect of colostrum intake on mortality and growth of Friesian bulls from birth to slaughter}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {382-385}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {Dairy cow glucose requirements increase dramatically during the weeks preceding calving, suggesting that supplements that increase glucose supply (rapidly fermentable carbohydrates) would reduce precalving mobilisation of body tissue and improve subsequent milk production. Sixty-eight multiparous dairy cows were randomly allocated to one of two diets for 36 {\textpm} 8.7 days precalving. All cows were fed pasture and pasture-silage precalving, with one group also receiving 3kg DM of a barley-maize concentrate. Precalving diets were iso-energetic (114 MJ/cow/day).At calving, cows within each precalving feeding treatments were randomly allocated to two dietary treatments for 35 days in a 2x2 factorial arrangement. Postcalving, all cows received pasture and pasture silage with one group also receiving 5.0 kg DM of a barley-maize concentrate. Postcalving diets were alsoiso-energetic (179 MJ/cow/day). Milk yield and composition, and liveweight (LW) and body condition score (BCS) were assessed weekly for five weeks. Blood was sampled on day -21, -14, -7, 0, 1, 2, 3, 4, 7, 14, 21, 28 and 35 relative to calving, and plasma samples were analysed for indicators of energy status. Average milksolids yield (1.9 kg/cow/d) during the five weeks postcalving was not affected by either pre- or postcalving concentrate supplementation, although protein to fat ratio was higher in supplemented cows. Similarly, concentrate supplementation pre- or postcalving did not affect either LW or BCS change before or after calving. Cows receiving concentrates precalving had higher (P<0.001) plasma non-esterified fatty acid (NEFA) concentrations, but otherwise were not different to those receiving an equivalent energy intake from pasture and pasture silage. Postcalving concentrate supplementation increased (P<0.01) plasma glucose and NEFA and decreased (P<0.001) plasma B-OH butyrate. Results suggests little effect on milkproduction by replacing energy from structural carbohydrates in high quality pasture with energy from non-structural carbohydrate during the transition period. }, issn = {1176-5283}, author = {Muir PD and Thomson BC and Fugle CJ} } @conference {41934, title = {Effect of cow genotype and feed allowance on milk composition}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {397-402}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {The effect of strain of Holstein-Friesian and level of feed allowance on milk composition, individual milk proteins, and minerals was examined in a seasonal calving pastoral dairying system. The trial included two high genetic merit strains of either North American (OS90) or NZ (NZ90) genetics, and one strain representing NZ 1970{\textquoteright}s genetics (NZ70). Each strain was farmed under systems designed to provide total feed allowances of 4.5 to 7.0 t DM/cow/year. Milk composition was affected by strain of cow and by feed allowance. Strain of cow influenced crude protein (P<0.05), true protein (P<0.01) and casein (P<0.01) concentrations, with the NZ90 and OS90 strains having higher concentrations than the NZ70 strain. Increased feed allowance resulted in increased crude protein (P<0.05), true protein (P<0.05) and casein (P<0.05) concentrations. Strain, but not increased feed allowance affected the protein:fat ratio, with the OS90 strain having a higher ratio (P<0.05) than the NZ strains. Strain altered concentrations of {\'a}-casein (P<0.05), with NZ90 having the highest concentrations and NZ70 the lowest concentrations. No consistent effect of strain or feed allowance was determined on whey proteins except for {\^a}-lactoglobulin (P<0.027), where the OS90 strain had higher concentrations than the NZ strains. No consistent effect of strain or increasing feed allowance was seen on milk mineral concentrations. These results demonstrate that different selection and breeding policies have influenced major milk components which may influence milk processing and product characteristics. }, issn = {1176-5283}, author = {Turner S-A and MacDonald KA and Back PJ and Thomson NA} } @conference {41681, title = {Effect of dairy cow breed on the metabolic adaptation to lactation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {390-396}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {Three breeds (20 Friesian, 20 Jersey and 20 Jersey/Friesian crossbred multiparous cows) were used to determine the effect of breed on indicators of metabolic status and the post partum anovulatory interval (PPAI). Effect of breed on circulating concentrations of metabolites and hormones, liver mRNA levels and PPAI was established. Weekly blood samples were taken for the first 6 weeks of lactation. Liver biopsy samples were taken from a sub-sample of cows of each breed between 23-33 days post partum, to determine levels of expression of T-GHR, GHR-1A and IGF-1 receptors using RT-PCR. Milk progesterone analysis was used to determine PPAI. There was a significant breed effect on circulating concentrations of {\^a}-hydroxy butyrate (P<0.01), non-esterfied fatty acids (P<0.001), triacylglycerols (P<0.001) and leptin (P<0.01), with Jersey cows having higher concentrations of these hormones and metabolites than Friesian or crossbred cows. Despite the concentration differences between breeds, only leptin showed a significant difference (P<0.01) in the rate of change in concentration across time between the breeds. Jersey cows were observed to have shorter PPAI (34 vs 42 and 44 days for Friesian and crossbred cows respectively: SED 6 days) but this was not statistically significant (P=0.18). There was no difference in the expression of mRNA levels of TGHR, GHR-1A and IGF-1 receptors in the liver. It appears that grazing Jersey cows have a different fat metabolism, which affects the regulation of circulating leptin concentrations and this may have contributed to their apparent ability to return to cyclicity earlier. }, issn = {1176-5283}, author = {Back PJ and Meier S and Barnett CME and Cursons RT and Thomson NA} } @conference {41652, title = {Effect of genotype and diet on milksolids production, body condition, and reproduction of cows milked continuously for 600 days}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {245-251}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {Milking cows for two consecutive years, with calving and mating occurring every second year, may exploit the superior lactation persistency of high yielding cows while improving reproductive performance. This study tested the feasibility of extended lactations in pastoral systems using divergent dairy cow genotypes (New Zealand [NZ] or Overseas [OS] Holstein-Friesian [HF]) and levels of nutrition (0, 3, or 6 kg concentrate DM/cow/day). Cows calved on 28 July 2003 and remaining cows were dried off by 6 May 2005. Of the 56 cows enrolled, 93\% were milking at 500 days in milk (DIM) and 18\% were milking at 650 DIM. Dietary treatments did not affect DIM (605 {\textpm} 8.3; Mean {\textpm} SEM), but there was a trend (P=0.09) for OS HF to have longer lactations than NZ HF. Genotype x diet interactions were detected for the total yield of milk and milksolids per cow, and as a percentage of liveweight. Differences between genotypes were greatest at the highest level of supplementation. Compared to NZ HF, OS HF produced 35\% more milk, 24\% more milk fat, 25\% more milk protein, and at drying off had 1.9 units less body condition. Annualised milksolids production from NZ HF was 79\% of a normal season{\textquoteright}s production, compared to OS HF that produced 94\%. Compared to NZ cows, OS cows had a similar 21-day submission rate (85\%), a lower 42-day pregnancy rate (56\% vs. 79\%), and a higher final empty rate (30 vs. 3\%) when mated at 451 days after calving. These results indicate that productive extended lactations up to 650 days are biologically possible on a range of pasture diets, and with appropriate cow genetics and feed management may ameliorate poor reproductive performance in high yielding dairy cows without sacrificing milksolids production. }, issn = {1176-5283}, author = {Kolver ES and Roche JR and Burke CR and Aspin PW} } @conference {41940, title = {The effect of maternal nutrition during gestation on the reproductive success of female progeny as 2-tooths}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {434-438}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {The inter-generational effect of birth rank and nutrition during pregnancy was assessed by examining the reproductive success of female progeny at their first mating at 2 years of age. Fifty-six ewes born as a twin or triplet and whose dam was maintained on 2 or 6 cm sward height from mid-pregnancy to parturition were synchronised and bred to Romney rams. Pregnancy diagnosis was conducted using ultrasound on day 71 from the start of mating (P71). All ewes were maintained as one mob under commercial farming conditions throughout pregnancy. Within 12 hours of birth lambs were ear tagged, weighed and body dimensions (CRL, girth, forelimb and hind limb lengths) were recorded. Lamb live weights were also recorded at day 48 after the mid-point of lambing (L48). Fifty-one ewes lambed of the 56 ewes that were bred. Twin-born ewes had significantly longer gestation lengths (by 1.3 days) than triplet-born ewes. Singleton lambs born to triplet-born ewes were significantly (P<0.05) lighter (4.6 kg) at birth than singleton lambs born to twin-born ewes (5.1 kg). Singleton lambs whose grand-dams were maintained on 2cm pastures during pregnancy and whose dam was born as a twin had significantly (P<0.05) longer hind limbs than their counterparts whose grand dam was maintained on 6 cm and whose dam was born a triplet but they did not differ in birth weight. Dam birth rank and the nutritional treatment of their grand-dam had no significant effect on twin-lamb live weight and body dimensions at birth. These results suggest that selecting triplet ewe lambs for breeding could have detrimental effects on flock productivity. In addition a previous study involving the same animals reported triplet born ewes displayed poorer maternal behaviour. To the authors knowledge this is the first finding of this kind and could have implications for ewe selection on New Zealand farms. }, issn = {1176-5283}, author = {Corner RA and Kenyon PR and Stafford KJ and West DM and Morris ST} } @conference {41689, title = {The effect of nutrition during pregnancy on the behaviour of adolescent ewes and their lamb(s) within 12 hrs of birth}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {439-443}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {Hogget mating has become more common in recent times as a management strategy to produce additional lambs. The productivity of hogget mating is limited by low lamb birth weights and poor lamb survival. A study has shown that maternal nutrition during pregnancy in hoggets had no effect on the birth weight or survival of lambs. This study investigated the effect of nutrition during pregnancy on the post-parturient behaviour of hogget ewes and their lambs. On day 13 after the mid-point of breeding hogget ewes were stratified by breed and live weight and randomly allocated to one of three feeding regimes: Low (gained 10kg of live weight by parturition), Medium (20kg) and High (30kg). Within 12 hours of birth lambs were ear tagged and the maternal behaviour of hogget ewes was recorded using a maternal behaviour score (MBS) a five point measure of a ewe{\textquoteright}s response to the handling of her lambs. Behavioural observations of the hogget and her lamb(s) were made for 5 minutes after the completion of tagging the lamb. Singleton-bearing hogget ewes fed on the high plane of nutrition had significantly (P<0.05) greater maternal behaviour scores than singleton-bearing hoggets fed on low or medium planes. In the low fed group, significantly (P<0.05) fewer hoggets bleated in response to their lamb (60\%) compared with medium (73\%) and high (85\%) fed hoggets. Of the lambs that bleated, those born to hoggets in the medium fed group bleated significantly (P<0.05) more than lambs born to hoggets in the low or high fed groups. Feeding hogget ewes on a high level of nutrition had a positive impact on hogget and lamb behaviour within 12 hours of birth. A high level of nutrition during pregnancy may result in behaviours that increase survival of lambs born to hogget ewes. }, issn = {1176-5283}, author = {Corner RA and Kenyon PR and Stafford KJ and West DM and Morris ST} } @conference {41639, title = {Effect of Se-amended fertilisers on the Se status of grazing dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {182-186}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {Selenium (Se) is an important trace element for dairy cattle and deficiencies (0.03 mg Se/kg DM) are associated with lowered milk yields and impaired fertility in grazing cows. As many dairy farms have a comprehensive fertiliser programme the use of Se-amended fertilisers (prills) could be an effective approach to prevent Se deficiency. Three farmlets (6-7 ha) were established and grazed with 13 cows/farmlet balanced for age, calving date and production. The treatments were 1) untreated control, 2) Sel Se prill (Selecote Ultra), and 3) Rav Se prill (Ravensdown Selprill Double). The prills were mixed with 15\% potassic superphosphate and applied at 250 kg/ha, in early October, to provide 10 g Se/ha. This is Day 1 of the study. The cows were allocated to treatments 4 weeks later and changes in pasture Se, blood Se, serum Se, milk Se concentrations and blood glutathione peroxidase activity were monitored over the next 12 months. Untreated pasture Se concentrations ranged from 0.03 to 0.04 mg/kg DM, while pastures treated with prills had pasture Se concentrations > 0.5 mg/kg DM within 14 days after treatment, before decreasing to 0.06 mg/kg DM after 121 days, after which they ranged between 0.06 and 0.26 mg Se/kg DM for the Sel prill, and between 0.06 and 0.03 mg/kg DM for the Rav Se prill over the next 251 days. The mean ({\textpm} SE) blood Se of cows grazing the control pasture was 280 {\textpm} 30 nmol/L, while in cows grazing pasture treated with the Sel Se prill blood Se concentrations increased to 1364 {\textpm} 112 nmol/L after 372 days. In the case of cows grazing pasture treated with Rav Se prill, blood Se concentrations increased to 1192 {\textpm} 66 nmol/L within 60 days, before decreasing slowly to 740 {\textpm} 65 nmol/L at 372 days. Blood glutathione peroxidase activity followed a similar pattern to the blood Se. The mean serum Se concentrations of the untreated cows was 151 nmol/L, while in animals on the Sel Se prill-treated pasture they reached a small peak at Day 64, followed by a decrease and then continued to increase to 675 nmol/L at Day 372. In contrast, for cows on the Rav Se prill treatment the serum Se concentrations reached a peak of 920 nmol/L at Day 64, and then decreased to 263 nmol/L at Day 372. Milk Se followed a similar pattern to serum Se. Selenium-amended fertilisers were found to be effective in raising the pasture Se concentrations for 4 or 12 months, depending on Se prill composition, which then in turn increased blood Se concentrations of dairy cows for at least 12 months. }, issn = {1176-5283}, author = {Grace ND and West DM} } @conference {41894, title = {Effect on fleece weight of combining genes from four flocks independently selected for increased fleece weight}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {195-199}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {This study investigated whether heterosis was present when crossing sheep from four closed Romney flocks selected for increased fleece weight. Three of the flocks had been developed by AgResearch (C, W and H) and one by Massey University (M). Each ewe was joined with a single ram according to a diallel design to generate single-line, two-line and four-line cross progeny. The trial ran from 1988 to 1996 with 599 records available for analysis. In rank order, the mean ({\textpm} standard error of mean) greasy yearling fleece weight (kg), adjusted for year, sex, pre-shearing live weight and days of wool growth was W (3.41 {\textpm} 0.08), H (3.39 {\textpm} 0.12), C (3.31 {\textpm} 0.10), M (3.10 {\textpm} 0.15) for the "single-line" groups, WC (3.40 {\textpm} 0.09), MW (3.36 {\textpm} 0.10), CH (3.24 {\textpm} 0.08), WH (3.16 {\textpm} 0.11), MH (3.14 {\textpm} 0.11), MC (3.14 {\textpm} 0.10) for the "two-line" crosses and 3.26 {\textpm} 0.06 for the four-line cross. Combining sheep from two or more flocks independently selected for increased fleece weight resulted, on average, in no heterosis in wool production among resultant progeny. }, issn = {1176-5283}, author = {Sumner RMW and Clarke JN and Blair HT and Cullen NG and Henderson HV} } @conference {41667, title = {Effects of artificial insemination on the incidence of long return intervals}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {325-328}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {The Phantom Cow Syndrome is a major impediment to achieving compact conception patterns in Victorian herds. Some inseminated cows fail to return for a further insemination even though they are not pregnant because the corpus luteum formed following insemination is maintained for an extended period. Five years of records were obtained from a herd of Holstein cows in Northern Victoria. Each cow was fitted with a hock tag that combined electronic identification with pedometer monitoring for oestrus. It was the only detection method used within a herd of up to 550 cows that had three AB programs of 6 to 8 weeks in each year. There were periods when cows detected in oestrus would be inseminated and others when they would not. Records were available for 2777 inseminations. The return intervals following these inseminations were classified as: Short (<18 days); Normal (18 to 24 days); or Long (>24 days). The overall conception rate for the 2777 inseminations made from 41 days to 160 days post-calving was 41.7\%. The 417 Long intervals represented 15\% of all inseminations and 25.8\% of cows not confirmed pregnant to a preceding insemination. Only 54 of 1459 oestrus events (3.7\%) not associated with an insemination were followed by a Long cycle (P<0.001). The proportion of Long returns declined linearly from 19.9\% among the 738 cows inseminated from 41 to 60 days post-calving to 7.4\% among the 189 cows inseminated from 141 to 160 days post-calving. These results demonstrated that the percentage of Long return intervals increased significantly following insemination. The magnitude of this increase declined with an increase in the interval from calving to insemination. }, issn = {1176-5283}, author = {Pino CS and Macmillan KL and Anderson GA} } @conference {41686, title = {Effects of conjugated linoleic acid on bioenergetics and milk production parameters in grazing dairy cows offered ad libitum or restricted pasture}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {423-428}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {Conjugated linoleic acids (CLA) reduce milk fat synthesis in grazing dairy cows and often improve net energy balance (EBAL). Study objectives were to determine if CLA-induced milk fat depression (MFD) could be utilised during times of feed shortage (i.e drought) to improve bioenergetic and milk production parameters. Twelve multiparous mid-lactation rumen-fistulated Holstein cows were offered ad libitum (AL) or restricted (R) pasture and abomasally infused twice daily with 0 (0) or 50 (50) g/d CLA in a cross over design. Treatment periods lasted 10 d and were separated by a 10-d washout period. Milk and plasma samples were averaged from d 9 and 10, and EBAL was calculated from d 6-10, of the infusion periods. Pasture restriction reduced (P<0.05) the yield of milk and milk components. CLA reduced (P<0.01) milk fat yield by 45 and 46 \% in AL and R, respectively. There was no effect of CLA on milk yield nor milk lactose content or yield, however milk protein content increased (P<0.05) in both AL and R, resulting in an increased (P<0.05) protein yield of 6 and 9\% respectively. The CLA-induced changes to milk fat and protein increased (P<0.01) protein:fat ratio by approximately 2-fold in both AL and R. Calculated EBAL improved following CLA infusion (-1.84 vs. 11.22 and 1.59 vs. 13.77 MJ/cow/d for AL and R respectively; P<0.05), however CLA did not alter plasma bioenergetic markers (including insulin, non-esterified fatty acids, {\^a}-hydroxybutyrate, urea and glucose). Data indicate that during short periods of nutrient restriction, CLA may provide an alternative management tool to improve milk protein:fat ratio and calculated EBAL, however further studies are required to determine if CLA is effective at improving bioenergetic parameters during more severe nutrient restriction. }, issn = {1176-5283}, author = {Kay JK and Mackle TR and Bauman DE and Thomson NA and Baumgard LH} } @conference {41918, title = {Effects of facial eczema on indole flavour compounds in dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {315-319}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {The flavour compounds indole and skatole (3-methylindole) are characteristic of products of pasture based production systems. The formation of these indoles by metabolism of the amino acid tryptophan in the rumen is favoured by high levels of readily-digestible protein in forage diets. However liver function is also a very important factor as indoles taken up into the animal are cleared by metabolism in the liver. An investigation of a persistent flavour taint from a dairy farm suggested a link between high milk indoles and facial eczema. As part of a genetic study, 1223 dairy cows in 4 herds in the Waikato and Bay of Plenty were screened for liver damage associated with facial eczema by measuring levels of the enzyme gamma-glutamyl transferase (GGT) in the blood. We examined levels of skatole in plasma from cows selected for high GGT (> 400 i.u. l-1, 47 cows) or low GGT (< 100 i.u. l-1, 43 cows) sampled from these herds. Blood indole and skatole levels overall were higher for the {\textquoteleft}high GGT{\textquoteright} cows compared to the {\textquoteleft}low GGT{\textquoteleft} cows (P < 0.001, Mann-Whitney test). The levels of indoles in milk collected from the same cows 4 days after blood sampling on one farm showed a highly significant (P < 0.001) non-linear relationship between levels in milk and blood, with milk fat skatole reaching extremely high levels (> 2000 ng g-1) in animals with very high blood skatole (> 20 ng ml-1). As the presence of relatively few animals with such extremely high levels of indole flavour compounds in milk is likely to raise the herd mean concentration to unacceptable levels, these findings suggest that facial eczema may have significant adverse effects on milk quality as well as on production. }, issn = {1176-5283}, author = {Fraser K and Lane GA and Morris CA and Cullen NG} } @conference {41884, title = {Environmental and physiological mechanisms underlying wool growth rhythms in New Zealand coarse wool sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {144-148}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {Coarse-woolled sheep breeds such as the Romney exhibit a pronounced annual cycle of wool growth with concomitant changes in fibre length growth rate and mean fibre diameter with maxima in summer and minima in winter. This cycle, which is entrained by seasonal changes in daylength via changes in circulating prolactin, parallels wool growth rate in Romney sheep. The cycle is also influenced by complex interactions between nutrient supply and hormones associated with reproductive status. A marked depression in wool production occurs during early pregnancy, which cannot be completely ameliorated by supplementary feeding, and does not directly involve prolactin. Additionally, in ewes, experimental and pharmacological increases and decreases in the prolactin concentration at parturition and during lactation are associated with increases and decreases, respectively, in spring and summer wool growth rate. A greater appreciation of the different mechanisms that temporally influence the wool growth cycle represents a potential means to change fleece characteristics. The development of sheep genotypes with a reduced amplitude of their wool growth cycle would significantly contribute to a reduction in fibre variability that can affect processing performance. }, issn = {1176-5283}, author = {Kendall PE and Sumner RMW and Pearson AJ} } @conference {41676, title = {An evaluation of sheep meat genetics in New Zealand: The central progeny test (CPT)}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {368-372}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {The New Zealand Central Progeny Test (CPT) was first established in 2001 with the aims of improving the carcass dollar value of sires and establishing genetic links among sire referencing schemes. Over the past three seasons, a total of 72 sires from both terminal and dual purpose breeds have been evaluated for meat genetics at the AgResearch Woodlands farm and the Lincoln University Ashley Dene farm. All progeny, except the 2004 born ewe progeny from the dual purpose sires, were slaughtered at monthly intervals from December to March each year through two Alliance plants, at threshold liveweights of 34kg. Carcass measurements included cut yield (measured by ViaScan grading) eye muscle area, GR, meat pH, meat and fat colour and days to reach an 18kg carcass weight. These measurements were used to calculate three key indices; days to kill, meat value and a combined meat and growth index, as well as individual breeding values. Results showed significant variation among sires for all key traits and that no single ram or breed dominated the top of the indices or breeding values. The range of economic value was approximately $10 across the terminal and dual purpose sires evaluated, demonstrating that considerable potential exists to identify and select better terminal sires. The CPT is now commencing maternal evaluation, using the retained ewe lambs produced from the dual purpose sires. }, issn = {1176-5283}, author = {McLean NJ and Jopson NB and Campbell AW and Knowler K and Behrent M and Cruickshank G and Logan CM and Muir PD and Wilson T and McEwan JC} } @conference {41857, title = {Face facts : drenching with anthelmintics for worm control selects for drug resistance - and no excuses!}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {4-13}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {Worm anthelmintic resistance is entering the final phase, where nothing remains with which to control worms at a level commensurate with profitable animal production. In Brazil, for instance, moxidectin alone or in combination with other compound(s) has failed in numerous cases in sheep and goats, and in New Zealand combined treatment of goats with moxidectin plus a benzimidazole and levamisole failed completely against Trichostrongylus and Ostertagia spp. Cattle follow closely behind, with a recent survey in Argentina indicating a prevalence of 55 \% of worm populations resistant to ivermectin. It is suggested that the solution for sustainable Integrated Parasite Management is use of systems of Targeted Selective Treatment (TST) to optimise application of the phenomenon of refugia for reduced worm selection. However, due to reticence of farmers and their advisors, the required major paradigm shift will be very difficult to achieve. To overcome this, it is suggested that dedicated software be developed for specific decision support at farm level, as detailed as the intervals between TST evaluations of a given flock/herd of animals and percentages of animals to examine and treat. The conclusion reached is to face the fact that no excuse regarding animal production or farmer reticence will expunge the reality that conventional worm control is leading to intractable resistance; optimum, not maximum production is the prerequisite. }, issn = {1176-5283}, author = {Van Wyk JA} } @conference {41640, title = {Further studies on the role of suckling in the parasite status of very young lambs infected with Teladorsagia circumcincta}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {187-192}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {This study investigated the role of suckling on the resistance and resilience of lambs during the period - six to 20 weeks after lambing. Eighty, 42-day old twin-born lambs were allocated to four treatment groups in which lambs continued to suckle (S-) or were weaned (W-), while concurrently infected with either 0 (-N) or 1000 (-I) L3 Teladorsagia circumcincta larvae d-1. Faecal egg counts peaked at 680, 1600, 260, and 225 eggs g-1 of fresh faeces in SI, WI, SN and WN lambs, respectively. Live weight gain was reduced from day 98 of age as a consequence of weaning (p<0.001) and infection (p=0.008). Serial slaughter on days 84, 112, and 140 indicated that suckling reduced the number of adult worms in SI compared with WI lambs though significantly so only on day 112 (p<0.05). In vitro larval establishment decreased (p<0.001) with slaughter age but was not influenced by suckling or infection (p>0.05). These results suggest that suckling may inhibit nematode development at a later stage than the immediate entry of incoming L3 larvae. In addition, suckling does not appear to confer greater resilience during T. circumcincta infection in young lambs. }, issn = {1176-5283}, author = {Iposu SO and Greer AW and McAnulty RW and Stankiewicz M and Sykes AR} } @conference {41883, title = {Gene markers for wool fibre traits}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {139-144}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {Selective breeding has been used for thousands of years to improve the quality and weight of wool, but surprisingly there is still a large amount of genetic variation present at the loci involved in the {\textquotedblleft}blueprint{\textquotedblright} for wool synthesis. This genetic heterogeneity results in considerable variation within, and between individual fleeces. This has both positive and negative implications. Where a wool processor requires uniformity in raw stock, both to gain efficiency in processing and to make a product to specification, it has a negative effect. Where specific traits convey unique properties it opens up opportunities for differentiated products. Markers for genes or knowledge of individual gene effects may be useful for identifying sheep with desirable wool traits that are difficult or expensive to measure under field conditions. The discovery of genetic variation in valuable fibre traits could allow the development of gene-marker tests which would assist breeding for more consistent wool.}, issn = {1176-5283}, author = {Abbott JKR and Hickford JGH and Sumner RMW} } @conference {41917, title = {Genetic parameters for resistance to facial eczema in dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {310-314}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {A project was designed to progeny-test dairy industry sires for their resistance to facial eczema (FE), as a preliminary step towards identifying DNA markers or genes for FE resistance. The FE disease is caused by the toxin, sporidesmin, produced by spores of a fungus, Pithomyces chartarum, found on many pastures in summer and autumn in the North Island of New Zealand. In susceptible animals, sporidesmin causes liver injury, and the cost of FE to the dairy industry is measured in tens of millions of dollars in years with serious outbreaks ($3.6 to 66.2M per annum). Earlier studies in New Zealand have established that resistance to FE in cattle is a heritable trait, with resistance measured by variation in activity in blood of liver-derived enzymes, gamma-glutamyltransferase (GGT) and the associated glutamate dehydrogenase (GDH). Widely used Friesian and Jersey sires were progeny-tested via 572 specially-reared sons (born in 2002-04 and dosed with sporidesmin), and also via 3761 daughters in autumns 2004 and 2005 in 17 herds with 3-22\% clinical cases of FE per herd. The data were combined from all sources, including four earlier years of GGT records (1173 animals born in the 1986, 1989, 1990 and 1992 birth years), and standardisation was applied to each contemporary group. Heritabilities were estimated for Friesians (0.47 {\textpm} 0.07 for log GGT; 0.32 {\textpm} 0.08 for log GDH) and for Jerseys (0.37 {\textpm} 0.06 and 0.39 {\textpm} 0.09, respectively), and there was a very high genetic correlation between activities of the two enzymes (0.93 {\textpm} 0.03). Sixty-eight sires had reliabilities of >0.70 for log GGT Breeding Value and 71 others had reliabilities between 0.60 and 0.70. The sires progeny-tested in this way generally were already proven for dairy traits and had been widely used, so that FE selection among these sires would be an additional trait when they were already old. Alternative approaches would be to performance-test young bulls for FE resistance, or to use sire and progeny data and their DNA to identify DNA markers or genes for FE resistance. }, issn = {1176-5283}, author = {Cullen NG and Morris CA and Hickey SM} } @conference {41874, title = {Genetics of stillbirth in dairy calves}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {98-102}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {The aim of this study was to investigate factors affecting, and estimate variance components of, stillbirth using data collected as part of Livestock Improvement{\textquoteright}s Sire Proving Scheme. Only calves that reached full-term of gestation were considered (i.e. abortions and inductions were excluded). After editing there were 773,904 records on calf-fate collected from 1987 to 2004. The mean incidence of stillbirth was 7.2\%. The fixed effect model fitted to the data included the effects of contemporary group, birth assistance code, the sex of the calf, the gestation length of the dam, whether the dam was primiparous or multiparous and mating type e.g. a Jersey cow mated to a Holstein-Friesian sire etc. Breed proportions of New Zealand (NZHF) and North American (OSHF) origin Holstein-Friesian and Jersey were also fitted in addition to the proportion of heterosis expected in the calf. Data were analysed by considering stillbirth as a binomial trait using the logit transformation in ASReml that included a sire-maternal-grandsire pedigree. The direct heritability of stillbirth was estimated to be 0.010 (s.e. 0.009). It was not possible to estimate the maternal heritability using this dataset. Estimates of fixed effects were obtained from ASReml by analysing stillbirth as a continuous trait, as back-transformed fixed effect estimates obtained using a binomial model are unreliable when the incidence is small. The largest effect on the probability of stillbirth was calving difficulty. Compared to no assistance at calving, the two categories of greatest calving difficulty resulted in 22\% and 41\% mortality. The next largest effect on stillbirth was gestation length, with longer gestations being associated with more stillbirths. Males were 1\% more likely to be stillborn than females. OSHF were most likely to be stillborn, followed by Jerseys and then NZHF. Heterosis effects were significant and favourable, except between the two strains of Holstein-Friesians where there was no significant heterosis. The largest heterosis estimate was between NZHF and Jerseys. Unlike some overseas programmes, genetically selecting for reduced stillbirths would not be effective in New Zealand, crossbreeding and devising strategies to manage calving assistance and gestation length appear to be more worthwhile. }, issn = {1176-5283}, author = {Pryce JE and Harris BL and Sim S and McPherson AW} } @conference {41625, title = {Genomic technologies to create new opportunities for wool growers - Introductory remarks}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {113}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {Efficient sheep farming of the future will demandreduced labour costs, ease of shearing, and minimised susceptibility to flystrike, while modern markets simultaneously demand reduced chemical use and high standards of animal welfare. Sheep witha reduced area of the body covered with fleece may provide a practical solution to these conflicting requirements. Research has shown that it is possible to select sheep for bare faces, legs, belly and breech, and that atleast some of these traits behave as though they are controlled by recessive genes, but that some only becomeevident later in life. Patterns of fleece distribution define major skin domains in the sheep that are evident in other mammals. We hypothesise that discrete skin domains arise because fibroblasts that induce wool follicle development originate from different embryonic tissues and carry with them differing developmental programmes for each follicle type. Identifying genes underlying variation in fleece distribution would allow desirable distributions to be established in sheep of diverse genetic backgrounds. Markers for distribution traits would enable us to introgress appropriate genes into flocks that do not carry them, and to determine early in life which animals might express the traits as adults.}, issn = {1176-5283}, author = {Pearson AJ} } @conference {41648, title = {Identification of commensal bacterial metabolites that enhance the integrity of the gastrointestinal barrier}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {225-229}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {The objective of this research was to identify metabolites produced by commensal bacteria that enhance the integrity of the gastrointestinal barrier (GIB). The integrity of the GIB is mainly determined by the complexity of interactions between tight junctions of opposing epithelial cells of the GI wall. This was measured using an in vitro bioassay, consisting of a monolayer of intestinal epithelial cells grown on a membrane. The trans-epithelial electrical resistance (TEER) across this monolayer was measured to determine the strength of the tight junctions. Preliminary results showed that a commercial probiotic product caused an increase in TEER across non-differentiated and differentiated monolayers by 178 {\textpm} 61\% and 40 {\textpm} 9\%, respectively. The maximum increases in TEER obtained with conditioned media fractions (media fractions containing components secreted by the probiotic product) was between 23 {\textpm} 6\% and 43 {\textpm} 4\%. The conditioned media fraction containing components less than 3 kDa accounted for the total activity of the whole conditioned media. Metabolite profiling of active conditioned media compared to inactive conditioned media using fast-LCMSMS identified numerous metabolites that may be responsible for this positive effect. Future work will isolate the candidate metabolites and screen them for GIB enhancing activity both in vitro and in vivo. }, issn = {1176-5283}, author = {Anderson RC and Cassidy LA and Cookson AL and Koulman A and Hurst RD and Fraser K and McNabb WC and Lane G and Roy NC} } @conference {41870, title = {Impaired insulin secretion in perfused pancreases isolated from offspring of protein malnourished rats}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {77-82}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {Insufficient maternal protein intake may contribute to changes in carbohydrate metabolism and subsequent diabetes mellitus in adult mammalian progeny. Here, female rats (a model of mammalian metabolism) were fed throughout pregnancy and lactation with otherwise-complete isocaloric diets sufficient (20\% whey protein, control (C)) or insufficient (5\% whey protein, low-protein (LP)) in protein. From weaning, all offspring ate diet C. Weight gain of LP mothers during gestation was less than C mothers (C: 117 g vs. LP: 78 g, SED = 9, P }, issn = {1176-5283}, author = {Barnett MPG and Phillips ARJ and Harris PM and Cooper GJS} } @conference {41613, title = {In vitro production of volatile fatty acids from forages}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {50-54}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {Volatile fatty acid (VFA) production from a range of fresh forages was measured in vitro over 24 hours (h). The forages comprised temperate and tropical grasses, legumes (including some containing condensed tannins; CT), herbs and silages, all of which were minced to resemble chewed forage and incubated in buffered media. Volatile fatty acid concentrations were measured in triplicate for each feed at 0, 6, 12 and 24 h. On average, VFA yields were 131, 226 and 311 mg/g dry matter (DM) between 0 - 6, 0 - 12 and 0 - 24 h, and the highest yields were from legumes (384 mg/g DM) and lowest from plantain (176 mg/g DM) after 24 h. Legumes containing CT produced 28\% less VFA than other legumes. The acetate + butyrate:propionate (A+B:P) ratio showed a substantial difference between forage types, ranging from an average of 2.5 (legumes) to 3.5 (tropical grasses) after 6 h, but differences between forage types diminished after 24 h. Multiple regression analysis showed a weak inverse relationship with NDF (neutral detergent fibre) after 6 h, but there was no clear relationship with particle size, chemical composition or digestion rates at 12 and 24 h. }, issn = {1176-5283}, author = {Burke JL and Waghorn GC and Brookes IM and Chaves AV and Attwood GT} } @conference {41913, title = {Increased hepatic skatole exposure via rumen infusion increases skatole concentration in peripheral circulation and inter-muscular fat in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {295-299}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {Skatole meat taint is unique to pastoral systems where high forage digestibility results in tryptophanderived skatole production at rates that exceed the clearance capacity of the liver. We hypothesise that under conditions of minimal endogenous skatole production (diet low in rumen degradable protein) a continuous rumen infusion of skatole will elevate hepatic exposure and modify tissue skatole metabolism. A 72 hour rumen infusion of skatole (140 mg/h; n = 6) dissolved in propane-1,2-diol (PD) or PD media alone (n = 6) was performed. Samples of rumen fluid and blood were collected at 0, 2, 4, 6, 8, 12, 16, 24, 48 and 72 hours for determination of skatole concentration. Infusion of skatole increased (P < 0.01) levels of skatole in rumen fluid (21 {\textmu}g/g), peripheral plasma (154 ng/ml) and inter-muscular fat (4240 ng/g). A two-compartment model was fitted to the rumen and plasma skatole concentration of treated sheep to estimate the rate of transfer from rumen to peripheral plasma (k = 0.23 {\textpm} 0.03/h) and the rate of elimination from peripheral circulation (k = 2.10 {\textpm} 0.56/h). A negative correlation (P < 0.05) between the rate of elimination and level of skatole deposition in inter-muscular fat was also found. }, issn = {1176-5283}, author = {Deighton MH and Pacheco D and Tavendale MH and Schreurs NM and Peters JS and McNabb WC and Roy NC} } @conference {41908, title = {The influence of red deer genotype on conception pattern : Eastern vs Western subspecies}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {270-273}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {Advancing the calving pattern of red deer from November/December to October/November would better align the nutritional demands of lactation to pasture quality and availability. This study investigated the hypothesis that red deer of {\textquoteleft}Eastern{\textquoteright} (E) genotype (Cervus elaphus hippelaphus) have advanced reproductive seasonality traits compared to those of {\textquoteleft}Western{\textquoteright} (W) genotype (C. e. scoticus). Hinds of E (135) or F1 (E x W; 165) genotype were single sire mated to one of 6 E stags, while W (506) hinds were single sire mated to one of 11 W stags. Reproductive seasonality traits measured were stag roaring and body condition score (BCS), and conception date as estimated by fetal aging. Peak roaring frequency occurred earlier in E than W stags (mean March total roars observed 144 vs. 68 for E and W stags respectively; SED 33.4; P }, issn = {1176-5283}, author = {Scott IC and Asher GW and Lach JE and Littlejohn RP} } @conference {41609, title = {Lessons from the national anthelmintic resistance surveys}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {23-26}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {Dexcel{\textquoteright}s Whole Farm Model (WFM) is a computer model of a dairy farm that simulates individual cows and paddocks, with pasture growth driven by observed climate data and with management policies guiding decisions on a daily basis. The aim of the study was to design a farm system to produce 1750 kg milksolids (MS)/ha/yr from feed grown on-farm. An average predicted pasture growth curve was derived by initialising the WFM for a typical all-pasture Waikato farm (3 cows/ha) with "best practice" management policies and running the simulation for 29 years of Ruakura climate data. The model was then used with this average growth curve to design the high producing system. Pasture growth alone (17.3 t DM/ha) did not fulfil the feed requirement for the 1750 kg MS/ha scenario, with an overall feed deficit of 3.1 t DM pasture/ha. Improvements in ryegrass cultivars and N-fertilisers could be expected to increase pasture production by around 10\%, reducing the overall feed deficit to 1.6 t DM pasture/ha. These improvements together with irrigation at 2 mm/day over the three summer months (Dec - Feb) reduced the feed deficit to zero. Irrigation could be replaced by cropping between 11\%and 20\% of the farm in a rotation of annual ryegrass yielding 7 t DM/ha and maize yielding 22 to 28 t DM/ha respectively.}, issn = {1176-5283}, author = {Pomroy WE} } @conference {41925, title = {Management and reproductive performance in herds that differed in their induction policies}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {355-359}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {A large scale retrospective study was undertaken in 2005 on the impact of the policies for induction of early calving (either undertaken during study period, stopped in previous 2 seasons, or continuing to induce) and other factors on herd reproductive performance. Data was gathered from whole-herd pregnancy testing data and farm visit records, and electronic records from the LIC database. Data analysed included records from 3 consecutive seasons from 82 herds, and included 34,729 cows, 72,593 calvings, 237,884 individual herd test records and summary pregnancy test results for each herd for 3 seasons. Factors that significantly influenced herd reproductive performance were herd induction policy, season, herd predominant breed, 4 week submission rate, average milk protein percent at herd test within 60 days following the start of the breeding programme, and length of breeding programme (all P< 0.01). Induction usage was found to be declining over time, implemented at a later stage of the calving programme and unlikely to meet Code of Practice requirements, and under-reported to the LIC database. This large-scale epidemiologic study provides important information for herd owners, their advisors, and other scientists on herd reproductive performance. }, issn = {1176-5283}, author = {Compton CWR and McDougall S} } @conference {41905, title = {Mastitis in cows milked in an automated or conventional milking system in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {252-257}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {The viability of automated milking systems (AMS) for pasture-based dairying has been studied in New Zealand in the past four years. Automatic milking differs from conventional milk harvesting systems (CMS) in a number of ways, which may impact on udder health. These include fewer machines/cow, distributed vs. batch milking, variable milking intervals, automatic udder health monitoring systems, and pre and post-milking teat sanitation procedures. Three seasons of data from two pasture-based research farms that milked cows with either a two unit AMS or a 30 bail rotary CMS were compared. Quarter milk samples were collected routinely from all cows for bacteriological analysis during the 2002-03, 2003-04 and 2004-05 seasons, with sampling occurring throughout lactation and at detection of clinical mastitis (CM) cases. The number of cows in the AMS herd ranged from 94 to 196 and in the CMS herd, from 289 to 324 across the seasons. Clinical mastitis affected 7, 11, and 15 cows/100 cows/season in the AMS herd and 24, 23 and 14 cows/100 cows/season in the CMS across the three seasons, with Streptococcus uberis isolated from approximately 50\% of CM cases from both herds. Prevalence of S. uberis post-calving averaged 8\% of cows for the AMS and 16\% for the CMS across the three seasons. We compared several indicators of udder health between an AMS and a CMS herd managed under pastoral conditions. }, issn = {1176-5283}, author = {Lopez-Benavides MG and Williamson JH and McGowan JE and Lacy-Hulbert SJ and Jago JG and Davis KL and Woolford MW} } @conference {41645, title = {Metabolomics for animal production : An introduction}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {209-212}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {Metabolomics will be one of the most important tools in the exploitation of the bovine genome sequencing project. The results of metabolomics will play important roles in many facets of animal production. This paper will give an introduction of metabolomics and its application in the field of animal production. It serves as the start of the metabolomics session at the 2006 conference of New Zealand Society of Animal Production covering the origin, analytical chemistry and ongoing research in metabolomics with a special focus on this research within New Zealand. }, issn = {1176-5283}, author = {Koulman A and Roy NC} } @conference {41889, title = {Methane emissions from growing beef cattle grazing hill country pasture}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {172-175}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {Methane (CH4) emissions from 12 Hereford x Friesian steers grazing hill country were measured on six occasions (6, 11, 13, 15, 23, and 26 months of age) during the months of February, July, September, November 2003, and October and November 2004 using the sulphur hexafluoride (SF6) tracer gas technique. These data are the first serial measurements of CH4/kg DMI on growing dairy beef cattle in New Zealand. Average daily methane ({\textpm} s.d.) emissions increased from 89 (10) g/head/d for 6 month old steers to 222 (46) g/head/d for 26 month old steers. The corresponding dry matter intake (DMI), predicted from energy requirements using the Feeding Standards for Australian Livestock, also increased from 3.6 kg/head/d to 12.0 kg/head/d for 6 and 26 month old steers, respectively. In contrast to the increasing DMI and daily methane emissions with age of the steers, the mean methane emission per unit of estimated intake was relatively constant at 17.3 (3.7) to 19.0 (5.6) g CH4/kg DMI from 11 to 26 months of age with a higher value of to 26.1 (7.0) g CH4/kg DMI for the 6 month old steers. The overall mean value of 19.5 ({\textpm} 5.2) g CH4/kg DMI is lower than that used in the current national inventory calculations. }, issn = {1176-5283}, author = {Molano G and Clark H and Knight TW and Cavanagh A} } @conference {41629, title = {Micro-arrays as a discovery tool for wool genomics}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {129-133}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {Wool follicle development and growth is a highly ordered and complex process involving the sequential expression of numerous genes within diverse cell populations. The aim of present studies using microarray analysis is to identify genes and pathways involved in the growth of wool follicles which could be utilised to increase farm productivity and improve the characteristics of Australasian wools. An ovine cDNA array was developed including sequences derived from sheep skin containing wool follicles in different growth stages encompassing many structural and regulatory genes necessary for follicular growth. Initial comparison of stages of wool follicle regression show marked changes in the expression levels of numerous genes including wool keratins. Two parallel research projects in Australia and New Zealand supported by SheepGenomics are currently utilising microarray technology to profile gene expression during key stages of wool follicle development in the foetus and follicular cycling associated with fleece shedding. }, issn = {1176-5283}, author = {Yu Z-D and Bawden CS and Henderson HV and Nixon AJ and Gordon SW and Pearson AJ} } @conference {41647, title = {Microbial metabolomics towards fibre digestibility in the rumen}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {219-224}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {Milking cows for two consecutive years, with calving and mating occurring every second year, may exploit the superior lactation persistency of high yielding cows while improving reproductive performance. This study tested the feasibility of extended lactations in pastoral systems using divergent dairy cow genotypes (New Zealand [NZ] or Overseas [OS] Holstein-Friesian [HF]) and levels ofnutrition (0, 3, or 6 kg concentrate DM/cow/day). Cows calved on 28 July 2003 and remaining cows were dried off by 6 May 2005. Of the 56 cows enrolled, 93\% were milking at 500 daysin milk (DIM) and 18\% were milking at 650 DIM. Dietary treatments did not affect DIM (605 {\textpm} 8.3; Mean{\textpm} SEM), but there was a trend (P=0.09) for OS HF to have longer lactations than NZ HF. Genotype x diet interactions were detected for the total yield of milk and milksolids per cow, and as a percentage of liveweight. Differences between genotypes were greatest at the highest level of supplementation. Compared to NZHF, OS HF produced 35\% more milk, 24\% more milk fat, 25\% more milk protein, and at drying off had 1.9 units less body condition. Annualised milksolids production from NZ HF was 79\% of a normal season{\textquoteright}s production, compared to OS HF that produced 94\%. Compared to NZ cows, OS cows had a similar 21-day submission rate (85\%), a lower 42-day pregnancy rate (56\% vs. 79\%), and a higher final empty rate (30 vs. 3\%) when mated at 451 days after calving. These results indicate that productive extended lactations up to 650 days are biologically possible on a range of pasture diets, and with appropriate cow genetics and feedmanagement may ameliorate poor reproductiveperformance in high yielding dairy cows without sacrificing milksolids production}, issn = {1176-5283}, author = {Villas-Boas SG and Noel S and Lane G and Attwood G and Cookson A} } @conference {41691, title = {Milk production in Romney ewes lambing out of season}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {450-455}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {Milk yield (MY) of groups of Romney ewes lambing at 3 times of the year: January (n=9), March (n=14) and June (n=13)) was measured on alternate days in the first week postpartum and at weekly intervals for nine weeks. Twin-bearing ewes produced significantly more milk than single-bearing ewes during the first week and during the whole of lactation (63 days) (P<0.05), except in the January-lambing group, in which ewes with single lambs produced more milk then those with twins during the first week. The shape of the lactation curve for ewes with singles or twins differed significantly (P<0.01) between lambing groups, reflecting that single- and twin-bearing ewes responded differently in January, but the number of twinbearing ewes was small (n=4) in that month. MY differed significantly (P<0.01) among groups lambing in January (single MY {\textpm} SEM: twins MY {\textpm} SEM) (1605 {\textpm} 57: 1402 {\textpm} 71 g/d), March (1425 {\textpm} 38; 1802 {\textpm} 46) and June (1520 {\textpm} 43: 1951 {\textpm} 54). Despite having the lowest (P<0.05) mean pre-lambing live weight (62 {\textpm} 3 kg), ewes lambing in June produced the highest overall mean MY (1735 {\textpm} 48 g/d), whilst ewes lambing in March and January had mean pre-weaning live weights of 70 {\textpm} 2 kg (in both groups) and produced 1613 {\textpm} 42 g/d and 1504 {\textpm} 64 g/d respectively. The June{\textendash}lambing ewes gained weight (1.38 {\textpm} 1.19 kg) and condition score (0.39 {\textpm} 0.16 /d) whilst weight loss was significant (P<0.05) in the March (-9.82 {\textpm} 1.15 kg) and January (-7.78 {\textpm} 1.44 kg) groups between pre-lambing and weaning, as was change in condition score (March: -0.49 {\textpm} 0.16; January: -0.63 {\textpm} 0.19). Lamb birth weights did not differ between seasons but ADG (g/d {\textpm} SEM) was highest (P<0.01) in June (0.262 {\textpm} 0.008), followed by March (0.238 {\textpm} 0.008) and January (0.202 {\textpm} 0.009). }, issn = {1176-5283}, author = {Peterson SW and Morel PCH and Kenyon PR and Morris ST} } @conference {41915, title = {Mycotoxin poisoning in grazing livestock in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {300-306}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {A number of mycotoxicoses including facial eczema, ryegrass staggers, paspalum staggers and zearalenone infertility affect grazing livestock, causing death and reducing productivity. While production losses associated with clinical disease are well recognised, losses associated with subclinical disease are not recognised and most farmers take few or no precautions against the diseases and consequently accept lower productivity levels as {\textquoteleft}normal{\textquoteleft}. For most mycotoxicoses there are no antidotes. Long-term research projects, some lasting decades, have led to the development of a number of control measures for particular diseases, especially facial eczema and ryegrass staggers. These measures depend primarily on identifying and avoiding toxic pastures, or reducing their impact. Under the current funding regimes, where funders seek quick returns, it is unlikely that many of these now widely used control methods would have come to fruition. }, issn = {1176-5283}, author = {Towers NR} } @conference {41662, title = {Mycotoxins in New Zealand livestock production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {300}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {An extended period of reproductive inactivity (anoestrus)is part of the normal recovery process in dairy cows, following calving. Low body condition at calving and long periods of negative energy balance affects the length of the post-partum anoestrous interval (PPAI). This study examined the effect of feeding two different supplementary feeds through early lactation, on the length of the post-partum anoestrous period. Forty-five mature dairy cows were allocated to either pasture (P; pasture allowance of 35 kg DM/cow/day), pasture plus a cereal (P+C; 3.0 kg/cow/day maize \& barley; 50\%: 50\%) or pasture plus a lipid supplement (P+L; 1.8 kg/cow/day lipid-based supplement, plus 180 ml/cow/day oil drench 33\% fish oil: 67\% linseed oil), starting in the first week post-calving and continuing for at least 7 weeks (range 7 to 15 weeks). The length of the anoestrous period was measured using twice weekly milk progesterone analyses, ending on the 8th October, 2004. An animal was identified as having ovulated when milk progesterone concentrations reached a threshold (>3ng/ml), this event was categorised as the initial ovulatory event (IOE). There was no effecton the interval from calving to IOE (35.7{\textpm}3.9 days, 32.8{\textpm}2.9 days, and 35{\textpm}3.9 days; mean{\textpm}SEM) for P, P+C and P+L groups, respectively. There was no effect of supplementation on either live-weight and body condition changes through early lactation. This study showed that when mature cows are fed a generous allowance of pasture post-calving, providing a cereal or lipid-based supplement during early lactation did not reduce the length of the PPAI.}, issn = {1176-5283}, author = {Morris CA} } @conference {41921, title = {A nutrient-signalling effect of grain feeding on postpartum anovulatory intervals in mature dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {334-338}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {Our previous study with mature dairy cows found that increased pasture intakes in early lactation resulted in more milk being produced but with no change in postpartum anovulatory intervals (PPAI). The present study used a 2 x 2 factorial to determine PPAI in 68 cows with pre- and post-calving diets that were iso-energetic, but varying in the ratio of structural to non-structural carbohydrate. At 36 {\textpm} 8.7 days prepartum, cows were assigned iso-energetic diets (114 MJ ME/cow/day) of either pasture/pasture silage (n=34) or the same diet supplemented with 3 kg DM/cow/d barley-maize concentrate (n=34). After calving, cows within each prepartum diet were assigned iso-energetic diets (179 MJ ME/cow/d) of either pasture/pasture silage (n=34) or the same diet supplemented with 5 kg DM/cow/d concentrate (n=34). Postpartum grain feeding reduced (P < 0.05) PPAI (28.4 {\textpm} 1.8 day) compared to the pasture/pasture silage only diet (36.4 {\textpm} 2.5 day). Prepartum diet did not affect PPAI. Body condition score was inversely related to PPAI at all time points (P < 0.05), but explained little (5-12\%) of the variability in PPAI. Significant relationships to PPAI were also found for blood non-esterified fatty acids, urea and magnesium, but again, r2-values were <= 0.1. None of the milk characteristics measured were significantly related to PPAI. This study supports the premise that discrete or specific nutritional cues unrelated to general energy status can favourably target physiological functions in reproductive tissues at the brain and/or ovarian levels. }, issn = {1176-5283}, author = {Burke CR and Roche JR and Aspin PW and Lee JM} } @conference {41878, title = {Options for change within the wool supply chain}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {113-119}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {Supply chains are the channels along which products flow from producer to processors and manufacturers, distributors and retailers until final consumers purchase them. The businesses along the chain are linked through the transactions between them and the information that they share. Wool is an inherently variable product that cannot be adapted quickly to changes in processor{\textquoteright}s requirements. As such it is a weak competitor in a section of the global textile marketplace dominated by synthetic textiles derived from petrochemicals. Nevertheless, wool has unique functional advantages over most synthetic fibres. Efficient supply chains are dependent on effective relationships between stakeholders. Reduction of costs incurred along the supply chain requires investment in horizontal and/or vertical relationships to improve information transfer between stakeholders, or to benefit from economies of scale and/or scope. Improved information transfer strengthens stakeholder confidence enabling the development of innovative business initiatives. }, issn = {1176-5283}, author = {McDermott AK and Sumner RMW and Scobie DR} } @conference {41935, title = {Plasma insulin, growth hormone, and IGF-1 concentrations of Holstein - Friesian cows of divergent genotype offered varying levels of concentrate in early lactation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {403-408}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {This study of insulin and key hormones of the somatotropic axis was made to help explain the milksolids and body condition responses obtained from cows of divergent Holstein-Friesian (HF) genotypes fed differing levels of concentrate. Weekly plasma concentrations of insulin, insulin-like growth factor-1 (IGF-1) and growth hormone (GH) were measured from 57 North American (overseas; OS) and New Zealand (NZ) cows in the first 10 weeks of lactation during the 2002/03 and 2003/04 seasons. Cows of similar breeding worth grazed at a high pasture allowance and were individually fed 0, 3 or 6 kg concentrate DM/cow/day. Compared to NZ HF, OS HF had similar insulin concentrations, lower IGF-1 concentrations, and higher GH concentrations. Feeding 3 or 6 kg concentrate DM/day increased insulin and IGF-1 concentrations to a similar extent, with GH concentrations being reduced at the highest level of supplementation. These results are consistent with the previously reported greater loss of body condition in OS HF, and suggest genotype differences in insulin resistance and rate of recoupling of the somatotropic axis after calving. The reported gain in body condition when concentrates were fed is probably a result of the increased insulin production and a positive effect on liver GH receptor 1A, with the consequent increase in IGF-1 and reduction in GH. Diet only began to affect GH concentrations, and therefore body condition loss, after approximately week 4-6 of lactation. These results have implications for feed management and breeding. }, issn = {1176-5283}, author = {Kolver ES and Roche JR and Aspin PW} } @conference {41871, title = {Plasma protein loss in lambs during a mixed infection of Trichostrongylus colubriformis and Teladorsagia circumcincta - a consequence of the immune response?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {83-87}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {Modelling is being used to compare and contrast farm management strategies. A Whole Farm Model (WFM) has been developed that links models for cow metabolism ({\textquoteleft}Molly{\textquoteright}) and pasture growth driven by climate, with management policies. It has been evaluated against trial data and the challenge is to now use it for prediction. This requires that cows be initializedso that their production is determined by their environment and genotype. Livestock Improvement Corporation has developed a system of quantifying genotype through production values (or PV{\textquoteright}s). The aim of this study was to assess the ability of the WFM to predict Strain Trial cow production using PVmilk. The relationship between PVmilk and milk yield and composition was determined by allowing a parameter within {\textquoteleft}Molly{\textquoteright} to adjust so that predicted matched actual production for 3 Strain herds and one Jersey herd. WFM was then initialized using observed PVmilk to set genotype of each cow in 8 other Strain herds and farmlets were simulated for 2003/04 season. Predictions were considered useful if the prediction errors for milk yield and milksolids (629 L and 61 kg MS respectively) were lower than the observed standarddeviations (825 L and 66 kg MS respectively) i.e. meaning model predictions of observed values were more accurate than simply using the mean as an estimate of observed values. The consistent under-prediction of milk yield and milksolids require further adjustments to the initialization of the model. PVmilk has the potential to set genotype in {\textquoteleft}Molly{\textquoteright}, within the WFM.}, issn = {1176-5283}, author = {Vaughan AL and Greer AW and McAnulty RW and Sykes AR} } @conference {41621, title = {Predicting cow production based on an estimate of animal genotype within a whole farm model}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {93-97}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {Body condition score (BCS) has been proposed for inclusion in the New Zealand national dairy index, Breeding Worth (BW), to account for replenishment of body tissue. Currently, the breeding objectives model positively accounts for body tissue mobilisation (through extra yield), but not the negative cost of replenishing body tissue. Two methods have been proposed: 1) Including BCS directly into BW by calculating and assigning an economic value to BCS and 2) Adjusting liveweight Breeding Values (BVs) for BCS, which would mean that liveweight BVs would beexpressed at a constant BCS (indirect method). Energy equations were used to calculate the direct economic value for BCS and included a sensitivity analysis. With an economic weight of $25, the percentage emphasis of BCS in BW would be 3.4\%. Including BCS in BW, either directly or indirectly, had little impact on sire rankings (rank correlations with and without BCS within breed were >0.99) and would only have a small impact on the economic response of BW ($0.02 net /cow/annum) and the improvement in BCS(0.006 BCS units/cow/annum). It is concluded that there would be little benefit to including BCS as an independent trait in BW. Body condition score is already included as a predictor in the genetic evaluation of fertility and breeding values for BCS will be estimated routinely from the fertility model.}, issn = {1176-5283}, author = {Beukes PC and Palliser CC and Lancaster J and Leydon-Davis C and Levy G and Folkers C and Macdonald K and Thorrold BS and Montgomerie B and Wastney M} } @conference {41657, title = {Preliminary survey of congenital and reproductive disorders in the New Zealand miniature horse population}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {274-278}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {The Miniature horse population is a rapidly expanding sector of the New Zealand (NZ) equine population. It is estimated that there have been 6,052 Miniature horses registered in NZ, with 677 new registrations in 2004. The lay literature implies that the Miniature horse breed has a high level of reproductive and congenital defects. To obtain reference data on the reproductive and congenital disorders of the NZ Miniature horse breed a face-to-face survey was conducted with 22 breeders located in the lower North Island of NZ. The 22 breeders were the owners of 421 horses (246 mares, 52 stallions, 88 foals and 35 geldings). The mean number of Miniature horses on the property was 19 horses (range 4-60), 11 broodmares (range 2-30) and 2 stallions (range 0 {\textasciidieresis}C 8). Most horses (75\%) were registered with the NZ Miniature horse Association or the American Miniature Horse Society (23\%). Most Miniature horses were type A, being <=86cm in height at the withers (72\%). The average foal crop per breeder was 7 foals, which were conceived with hand serving (61.4\%) or a combination of hand serving and having the stallion run with the mare (31.8\%).Confirmation of pregnancy was by blood test (49.2\%), ultrasound verification (19\%), combination of blood test and ultrasound (6\%), or non return to oestrus (23.4\%). Seventeen breeders had mares that were covered by the stallion during the season but did not return a positive pregnancy (23.4\% of mares covered in the season). There was a lower percentage of apparent fetal loss on farms that used blood tests or ultrasound to verify pregnancy compared to farm relying on non return to oestrus(10.38\% {\textpm} 2.49\% vs. 20.79\% {\textpm} 4.59\%, p=0.06).The incidence of fetal abortion (<300 days gestation) was 1.75\% (CI 0.5-3.03), and 5.2\% (CI 2.6 -7.8\%) of mares suffered from dystocia. The incidence for premature placental separation was 0.82\% (CI 0.26-1.39\%) and the incidence of retained placenta was 1.4\% (CI 0 -3.6\%). The incidence of dwarfism was 0.7\% (CI 0.11-1.28\%), with 11 breeders reporting foals that had excluded from the studbook due to dwarfism. The incidence of parrot and sow mouth was 1.22\% (CI 0 -2.43\%) and 0.45\% (CI 0- 0.84\%), respectively. The incidence of respiratory disorders (including signs indicative of collapsed trachea and cleft palate) was 2.2\% (CI 0.7 -3.7\%). The data collected indicate that the incidence of reproductive and congenital disorders in the New Zealand Miniature horse population is lower than expected. }, issn = {1176-5283}, author = {Rogers CW and Gee EK and Hangoor E and Firth EC} } @conference {41604, title = {Presidential Address 2005: Animal production - the bridge between animals on the farm and the consumer}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {1-3}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {The development of man from caveman to the sophisticated being that he is today has been dependent on us using the animals and plants surrounding us as a source of food, warmth and shelter. As we have developed so we have mastered the management of these resources to make life more comfortable. In managing these resources we have developed ways and means of manipulating animals and plants in various ways to produce special products. }, issn = {1176-5283}, author = {Sumner RMW} } @conference {41650, title = {Prevalence of mastitis for cows of different genotypes milked for two consecutive seasons}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {236-240}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {Extending the calving interval from the traditional 12-month to a 24-month calving interval has been suggested as a practical solution for maximizing lactation yield per calving. Somatic cell count (SCC) and the incidence of mastitis were examined in New Zealand (NZ) and overseas (OS) Holstein-Friesian cows fed on pasture alone or supplemented with 3 or 6 kg DM maize/barley concentrates/cow/day during an extended lactation of up to 21 months. Average cow SCC was three-fold higher (P<0.001) in the extended or second season of the lactation compared with the first season, with NZ cows having a slightly higher SCC (P<0.01) in the second season compared to OS cows (191,000 and 115,000 cells/ml respectively). The SCC elevations occurred regardless of infection status of the udder. Although OS cows tended to have twice as many cases of clinical mastitis (P=0.01) in the first season compared to the NZ cows, affecting 59\% and 27\% of cows respectively, there was no difference in infection status between genotypes in the second season (20\% and 18\% respectively). Results showed that although cows experienced less mastitis during the second spring of the lactation, the average cow SCC was higher during the extended part of the lactation. }, issn = {1176-5283}, author = {Lacy-Hulbert SJ and Summers EL and Williamson JH and Aspin PW and Kolver ES} } @conference {41859, title = {A profile of anthelmintic resistance and parasite control practices in New Zealand - results from a 2005 survey}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {14-19}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {Anthelmintic (drench) resistance in New Zealand{\textquoteright}s ruminant livestock is arguably the biggest single threat to sustainable future pastoral production. Clinical and sub-clinical parasitism impacts not only on animal health, but on animal welfare, and hence the image of pastoral production systems, total production and production efficiency and has a marked impact on the economic bottom line for both farmers and the country as a whole. In 2001 it was estimated for the relatively small NZ deer industry alone (worth $311 million in export earnings) that parasitism cost $12.8 million per annum in production losses due to parasitism and parasite control (Mackintosh and Wilson, 2002).}, issn = {1176-5283}, author = {Rhodes AP and Leathwick DM and Pomroy WE and West DM and Jackson R and Lawrence K and Moffat J and Waghorn TS} } @conference {41620, title = {Protein fractionation prototype to extract minor proteins on-farm}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {88-92}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {The aim of this study was to investigate factors affecting, and estimate variance components of, stillbirth using data collected as part of Livestock Improvement{\textquoteright}s Sire Proving Scheme. Only calves that reached full-term of gestation were considered (i.e. abortions and inductions were excluded). After editing there were 773,904 records on calf-fatecollected from 1987 to 2004. The mean incidence of stillbirth was 7.2\%. The fixed effect model fitted tothe data included the effects of contemporary group, birth assistance code, the sex of the calf, the gestation length of the dam, whether the dam was primiparous or multiparous and mating type e.g. a Jersey cow mated to a Holstein-Friesian sire etc. Breed proportions of New Zealand (NZHF) and North American (OSHF) origin Holstein-Friesian and Jersey were also fitted in addition to the proportion of heterosis expected in the calf. Data wereanalysed by considering stillbirth as a binomial trait using the logit transformation in ASReml that included a sire-maternal-grandsire pedigree. The direct heritability of stillbirth was estimated to be 0.010 (s.e. 0.009). It was notpossible to estimate the maternal heritability using this dataset. Estimates of fixed effects were obtained from ASReml by analysing stillbirth as a continuous trait, as back-transformed fixed effect estimates obtained using a binomial model are unreliable when the incidence is small. The largest effect on the probability of stillbirth was calving difficulty. Compared to no assistance at calving, the two categories of greatest calving difficulty resulted in 22\% and 41\% mortality. The next largest effect on stillbirth was gestation length, with longer gestations being associated with more stillbirths. Males were 1\% more likely to be stillborn than females. OSHF were most likely to be stillborn, followed by Jerseys and then NZHF. Heterosis effects were significant and favourable, except between the two strains of Holstein-Friesians where there was no significant heterosis. The largest heterosis estimate was between NZHFand Jerseys. Unlike some overseas programmes, genetically selecting for reduced stillbirths would notbe effective in New Zealand, crossbreeding and devising strategies to manage calving assistance and gestation length appear to be more worthwhile.}, issn = {1176-5283}, author = {Chand A and Fee CJ} } @conference {41939, title = {Quantitative genetic selection for twinning rate in ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {429-433}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {Data from 19 recorded sheep flocks were included in this study involving 324 thousand lambings from the 1970{\textquoteright}s up until the 2004 lambing season. The genetic correlation between number of lambs born, and a triplet trait coded as 1 for ewes lambing triplets or higher multiples, and 0 for ewes lambing singles or twins was estimated separately over 13 data sets. Genetic correlation estimates ranged between 0.78 and 0.95 with all but two dataset estimates differing from 1.00 by two or more standard error intervals. Flock differences in the relationship between mean NLB and the proportion of ewes lambing twins were also investigated through an analysis of sire mean results. Strong evidence was found for within flock genetic variation in twinning incidence that is independent of mean NLB. This is different to the clear relationship that exists between mean litter size of a group of ewes and the proportion that lamb twins. There were also meaningful differences across-flocks in the proportions of ewes lambing twins after accounting for the effects on twinning percent of flock mean litter size. Our analyses suggest that simple selection strategies such as screening in twin lambing ewes from a commercial flock, and/or, only using twin-born rams in the breeding flock, will be relatively ineffective for improving twinning rates. A recommendation arising from the study is that genetic evaluation tools for twinning be made available to New Zealand sheep breeders. These tools would allow breeders to select for decreased triplets without compromising genetic progress in other traits including mean number of lambs born. }, issn = {1176-5283}, author = {Amer PR and Bodin L} } @conference {41617, title = {Responses and factors affecting intramammary infection rates resulting from infusion of a Streptococcus uberis strain in Friesian - Jersey crossbred cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {70-76}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {The objective of this study was to investigate responses to an intramammary infusion of a Streptococcus uberis strain in 264 Friesian-Jersey cows, and identify factors contributing to clinical mastitis risk in the week following infusion. Factors examined for their contribution to risk include sire, days in milk at the time of infusion, SCC on the morning of infusion, previous mastitis treatment history, and the presence of any major pathogens at the time of infusion. Prior to infusion, milk samples were collected from all glands for bacteriology assessment, and antibiotic treatments were administered to clear infections. A single gland from each cow was infused with an average 104 colony-forming units (sd=22) of Streptococcus uberis, and milk samples were collected at each milking for the subsequent 13 milkings, or until diagnosis of clinical mastitis. Logistic regression and survival analysis were used to determine risk factors. Findings showed that cows with a somatic cell count at infusion of >=100,000 cells/ml had a lower incidence of clinical mastitis (18.3\% vs. 81.5\%; p<0.0001). Results also indicated that the presence of Staphylococcus aureus at infusion for cows that had no pre-infusion mastitis treatment(s) was associated with a lower incidence of clinical mastitis (29.0\% vs. 82.8\%; p<0.0001). }, issn = {1176-5283}, author = {Sanders KM and McDougall S and Stanley GE and Johnson DL and Spelman RJ and Harcourt SJ} } @conference {41664, title = {Review of zearalenone studies with sheep in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {306-310}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {Zearalenone is a naturally occurring mycotoxin from the Fusarium fungus which grows on pastures in New Zealand in autumn, and it has been found on farms in some years from Northland to Southland. The toxin may interfere with oestrogen-related functions in sheep during reproduction, reducing ovulation rates and fertility and thus lambing percentages, because its chemical structure is similar to that of reproductive steroids. Forty four per cent of over 6000 New Zealand pasture samples, collected in autumn and tested for zearalenone, were found to have high enough levels for ewe fertility to be either depressed (9\% of samples), or {\textquoteleft}at risk{\textquoteleft} (35\%). Control of zearalenone toxin production or of Fusarium growth on pasture on a large scale is currently not feasible. Attempts to mitigate its effects by immunisation have failed or even exacerbated the problem. Provision of alternative zearalenone-free feed crops is costly and generally uneconomic. Selection of sheep for genetic resistance would seem to be the most beneficial approach. Resistance to zearalenone is inherited in sheep (heritability estimate = 0.32 {\textpm} 0.10), and a test could be set up in ram-breeding flocks to select for resistance.}, issn = {1176-5283}, author = {Smith JF and Morris CA} } @conference {41678, title = {Sensitivity analysis of weaner lamb production in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {377-381}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {Many factors contribute to the profitability of sheep farms. A sensitivity analysis, using a simulation model, was conducted to investigate the impact of changes in pasture growth, ewe live weight, conception rate, ewe prolificacy (EP), lamb survival, lamb growth rate and lamb price on farm gross margin (FGM). The model simulated herbage growth and flock energy requirement on a daily basis over a one-year period starting on the 1st January and calculated gross margins for a 500 ha farm, using average Manawatu herbage growth rates. Ewe energy requirements were calculated as a function of live weight, lambing percentage, week of pregnancy or lactation and milk production and lamb energy requirements as a function of live weight, growth rate and body composition. The pre-weaning survival rate and lamb daily growth rate were adjusted for litter size. For each simulation, stocking rates were adjusted so that the pasture cover at the beginning and the end of the year was 1200 kgDM/ha. Simulations were conducted for different farm productivity levels ({\textquoteleft}Low{\textquoteright}, {\textquoteleft}Medium{\textquoteright} and {\textquoteleft}High{\textquoteright}). Results of the simulations show that, over all farm productivity levels, lamb price and growth rate had the largest impact on FGM followed by ewe liveweight, EP, conception rate and herbage growth. However, the ranking and the effect of these parameters on FGM varied across farm types. For example in "Low productivity farms" a 1 \% increase in lamb growth rate has the same impact on FGM as a 1 \% increase in EP (+$5.4 / ha vs +$5.9 / ha) and in "High productivity farms" a 1 \% increase in lamb growth rate is equivalent to a 3 \% increase in EP (+$11.2 / ha vs +$11.1 / ha). This illustrates that for each specific farm production level there are different management strategies to optimize FGM. It was also found that the relationship between EP and FGM was not linear. Across the liveweight ranges a one percent increase in EP between 140\% and 160\% increases FGM by $3.95 /ha, between 160\% and 180\% by $2.51 /ha, between 180\% and 200 \% by $1.33 /ha, between 200\% and 220\% by $2.83/ha, and between 220\% and 240\% by $2.33/ha. Simulation models can be useful tools when considering farm management decisions as they help identify optimal management systems and identify areas that may require further research. }, issn = {1176-5283}, author = {Morel PCH and Kenyon PR} } @conference {41615, title = {Sheep and deer grazing of pasture close to cattle dung pats}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {59-63}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {An experiment compared the grazing of deer and sheep on pasture with or without contamination by cattle dung pats. Sheep (35 ewes) and deer (24 hinds) separately grazed 0.4 ha plots of a ryegrass/white clover pasture. Half of the area (4 subplots) was contaminated with artificially applied cattle dung pats (DP), 30 cm in diameter, using fresh cattle dung at an application rate of 1 dung pat per 4 m2. The remaining four subplots were left uncontaminated (NDP). Mean pasture mass was estimated daily (rising plate meter) on DP and NDP plots. In addition, pasture height (sward stick) was recorded daily at 10 cm intervals from 0 to 100 cm from pre-marked dung pats and from pegged point sources in NDP plots. The experiment lasted 10-11 days and mean pasture mass declined from 2850 to 1500 kg DM/ha. Grazing pressure was controlled by altering numbers of livestock to maintain < 250 kg DM/ha difference between each species plot. There was no difference in the mean pasture mass of the sheep or deer grazed plots at any stage of the experiment. However both species grazed pasture near pegs (NDP plots) to a lower mean height (P<0.001) than near dung pats although the difference was greater for deer (7.4 and 9.0 cm near pegs and near dung pats respectively) than sheep (8.0 and 8.3 cm near pegs and dung pats respectively). Sward height of pasture at 10-20 cm from dung pats grazed by deer was higher than sheep grazed pasture for days 1, and 3-7 of the trial (P<0.001). The results from this experiment indicate that although deer graze pasture around cattle dung pats, they show more of a preference for grazing further away from dung pats than do sheep. This finding should help to establish the potential for deer to substitute for sheep under mixed grazing situations involving cattle. }, issn = {1176-5283}, author = {Trotter CG and Nicol AM and Ridgway MJ} } @conference {41879, title = {Sheep genomics - a trans-Tasman collaboration}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {119-124}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {SheepGenomics is a major A$30 million initiative of Meat and Livestock Australia and Australian Wool Innovation Limited supported by 10 leading research organisations in Australia and New Zealand. It aims to discover genes that influence economically important traits in sheep. By using discoveries made within SheepGenomics{\textquoteright} research program, sheep producers will be able to start breeding for a wide range of economically important traits with greater confidence than is currently possible. One of the themes in the programme is to improve key aspects of wool quality and focus on genes that regulate follicle formation in the skin of foetal lambs. This paper describes key aspects of the management structure of SheepGenomics, an overview of three of the Subprograms (Muscle, Parasites and Coretech) and a more detailed description of the Wool Subprogram. }, issn = {1176-5283}, author = {Forage RG and Hynd PI} } @conference {41860, title = {The sheep sustainability strategy : Project introduction and preliminary results}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {20-23}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {From the preliminary results in Table 2 a number of tentative conclusions can be drawn. It can be seen that a Levamisole drench is an effective option on many of the properties. A Combination (BZ \& Lev) drench is effective on many properties also probably as a result of the Levamisole active efficacy. There is a high percentage of Ivermectin (Full dose) failure across the properties {\textendash} one possible reason for this could be the high volume of Ivermectin used within the merino and mid micron sectors over recent years. It has been speculated that this high level of Ivermectin (full dose) usage was a result of early BZ drench failure (undiagnosed) in the mid micron and merino sectors.}, issn = {1176-5283}, author = {Bates J and Mirams G and Hickford J and Hill S} } @conference {41911, title = {A simple HPLC method for measuring sulfate in ultra filtered sheep plasma}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {284-289}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {Plasma sulfate concentration is a useful indicator of sulfur amino acid oxidation. Measurement of sulfate in water and other fluids has been made by turbidimetric, ultra-violet (UV) absorption or ion chromatography HPLC methods. The turbidimetric method is variable and suffers from interferences and both turbidimetric and UV methods are less sensitive than ion chromatography. We describe a quick and simple HPLC method, where sample preparation is a centrifugal filtration and the sulfate measurement is by single column HPLC using one buffer at a constant flow rate. Recoveries from spiked samples were 99.5 \% (RSD 1.8 \%) and the RSD of repeated standards over 6 weeks was 0.7 \%. Using this method, we measured plasma sulfate levels in both growing lambs with intestinal parasites and in sheep fed fresh Lotus corniculatus containing condensed tannins (CT) or other fresh forages. The CT in Lotus corniculatus decreased (P < 0.05) plasma sulfate concentration while parasite infection did not (P > 0.05). Our method provided quick and reliable data that could be transferable for measuring sulfate in blood, serum and other biological fluids and could be used as a biomarker of whole body sulfate status under various physiological conditions in farm animals. }, issn = {1176-5283}, author = {Sinclair BR and Tavendale MH and Bermingham EN and Burke JL and McNabb WC and Roy NC} } @conference {41641, title = {Sources of dark fibre contamination in some lines of mid-micron fleece wools - Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {193-194}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {High-throughput technologies in the era of post-genomics provide new opportunities to investigate complex biological systems. Data can be collected for a system of interest at the level of gene expression, protein expression and metabolite concentration changes and then used for the assessment of interactions of molecules. However, the vast amount of information also poses challenges for data management, analysis, and interpretation. This paper aims to outline the technical complexity and the sources of variation in the technologies involved in molecular systems biology and computational strategies for data integration.}, issn = {1176-5283}, author = {Reid TC and Urquhart RA} } @conference {41654, title = {Stage of lactation affects the milking performance and behaviour of cows in a pasture-based automated milking system}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {258-262}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {The successful implementation of automatic milking (AM) technology in pastoral dairy systems is dependent on the regular voluntary passage of cows from the grazing area to the dairy. A herd of 94 cows at the Dexcel Greenfield research farm was observed during a 31-day period to determine the effect of stage of lactation on milking performance and behaviour. Sixty-five cows were spring calved (late lactation, average 266 days in milk) and 29 were autumn calved (early lactation, average 19 days in milk). Cows were grazed as one herd in a rotational grazing management system with a fresh area of pasture available twice daily. Early lactation cows had a shorter average milking interval (14.6 vs 20.4 hours, p < 0.001) and a higher average daily production (20.0 vs 7.0 kg milk/cow/day, p < 0.001). They visited the selection units (from which they could gain access to water, fresh pasture and the raceway to the dairy housing the AM units) more often than cows late in lactation (2.8 vs 1.8 visits/cow/day, p < 0.001) and had a quicker transit time between pasture and the AM units (2.2 vs 2.7 hours/cow/milking, p = 0.026). Fewer early lactation cows needed to be manually moved from the grazing area for milking. The data indicates that stage of lactation will be a significant factor to consider when developing management systems for combining grazing with automatic milking. }, issn = {1176-5283}, author = {Jago JG and Davis KL and Woolford MW} } @conference {41644, title = {A study of pelt and growth traits in Zandi sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {206-208}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {The combination of metabolic profiling by a combination of broad-spectrum analytical methods and multivariate statistics offers new opportunities for obtaining a global over-view of metabolism. It also facilitates the discovery of metabolites which can serve as useful markers of biological processes or states ({\textquotedblleft}biomarkers{\textquotedblright}). Fast liquid chromatography and electrospray ionisation mass spectrometry with collisioninduced dissociation in an ion-trap (fast LC-ESI-MS/MS) has been applied to determine metabolic profiles of bovine urine samples. The samples were collected twice daily from groups of five lactating dairy cows grazing in four different forage management systems comprising different spatial and temporal allocations of ryegrass (Lolium perenne) and white clover (Trifolium repens). The data have been analysed by different multivariate statistical methods, and a number of candidate biomarkers of forage feed and diurnal processes have been identified.}, issn = {1176-5283}, author = {Khojasteh KM and Emam Jome NK and Torshizy RV} } @conference {41684, title = {Supplemental fumarate did not influence milksolids or methane production from dairy cows fed high quality pasture}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {409-415}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {This experiment tested the hypothesis that methane emissions from dairy cows would be reduced, and milk production increased, when sodium fumarate was added to a diet of fresh pasture at a rate of 5\% of dry matter (DM) intake. Sixteen ruminally fistulated dairy cows (100 {\textpm} 20.7 days in milk; 548 {\textpm} 47.8 kg liveweight; mean {\textpm} SD) received either a control (water) or fumarate treatment (10.3 {\textpm} 1.18 L/cow/day of solution providing 931 {\textpm} 126 g sodium fumarate/cow/day) over a 7-day adjustment period while grazing ryegrass pasture, followed by an 8-day experimental period fed pasture in metabolism stalls. During the experimental period cows on both treatments consumed 18.8 {\textpm} 1.83 kg DM/day, produced 1.81 {\textpm} 0.25 kg milksolids/day, and emitted 350 {\textpm} 44.9 g methane/day (5.9 {\textpm} 0.71\% of gross energy). Total tract DM digestibility was high (78.8 {\textpm} 0.84\%), and ruminal pH was 6.10 {\textpm} 0.15. Fumarate supplementation did not change ruminal fermentation, in vivo digestibility, methane emissions, milk production or composition, or selected plasma metabolites. The opportunity for reducing methane emissions from dairy cows by supplementing with fumarate or breeding high fumarate grasses may be limited for diets of high quality pasture. The limited reports of in vivo response to supplemental fumarate suggest that mitigation opportunities may be greater for pasture diets of low digestibility. }, issn = {1176-5283}, author = {Kolver ES and Aspin PW} } @conference {41937, title = {Supplementation with concentrates either pre- or post-partum does not affect milk production when diets are iso-energetic}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {416-422}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {Dairy cow glucose requirements increase dramatically during the weeks preceding calving, suggesting that supplements that increase glucose supply (rapidly fermentable carbohydrates) would reduce precalving mobilisation of body tissue and improve subsequent milk production. Sixty-eight multiparous dairy cows were randomly allocated to one of two diets for 36 {\textpm} 8.7 days precalving. All cows were fed pasture and pasture-silage precalving, with one group also receiving 3kg DM of a barley-maize concentrate. Precalving diets were iso-energetic (114 MJ/cow/day). At calving, cows within each precalving feeding treatments were randomly allocated to two dietary treatments for 35 days in a 2x2 factorial arrangement. Postcalving, all cows received pasture and pasture silage with one group also receiving 5.0 kg DM of a barley-maize concentrate. Postcalving diets were also iso-energetic (179 MJ/cow/day). Milk yield and composition, and liveweight (LW) and body condition score (BCS) were assessed weekly for five weeks. Blood was sampled on day -21, -14, -7, 0, 1, 2, 3, 4, 7, 14, 21, 28 and 35 relative to calving, and plasma samples were analysed for indicators of energy status. Average milksolids yield (1.9 kg/cow/d) during the five weeks postcalving was not affected by either pre- or postcalving concentrate supplementation, although protein to fat ratio was higher in supplemented cows. Similarly, concentrate supplementation pre- or postcalving did not affect either LW or BCS change before or after calving. Cows receiving concentrates precalving had higher (P<0.001) plasma non-esterified fatty acid (NEFA) concentrations, but otherwise were not different to those receiving an equivalent energy intake from pasture and pasture silage. Postcalving concentrate supplementation increased (P<0.01) plasma glucose and NEFA and decreased (P<0.001) plasma B-OH butyrate. Results suggests little effect on milk production by replacing energy from structural carbohydrates in high quality pasture with energy from non-structural carbohydrate during the transition period. }, issn = {1176-5283}, author = {Roche JR and Lee JM and Aspin PW and Sheahan AJ and Burke CR and Kolver ES and Sugar B and Napper AR} } @conference {41890, title = {Supplementing dairy cows with oils to improve performance and reduce methane ? does it work?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {176-181}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {Oil supplements can be used in dairy rations to increase dietary energy density (and energy intake) and reduce methane (CH4) emissions from rumen fermentation. Trials at Dexcel measured effects of oil supplementation on dry matter intake (DMI), milk yield and methane production after lactating dairy cows were fed pasture-based diets for short (14-day) and long (12-week) periods. In the short-term trial, 32 cows received either no oil or three mixtures of sunflower and fish oil at 500g/d. In the long-term trial 20 cows grazed pasture and received either no oil or 300g linseed and fish oil for 11 weeks prior to methane measurements. The type of oil in the short-term trial did not affect methane production and oils had no effect on DMI or milk yield but reduced total methane emissions by 27\% (176 vs. 242g CH4/cow/d, sed=10.6) and CH4/kg DM (13.5 vs. 18.5g CH4/kg DM, sed=0.88). In the long-term trial, oil had no effect on methane emissions (353 (oil) vs. 323g CH4/cow/d (control), sed=17.0 and 21.7 vs. 23.0g CH4/kg DM, sed=1.01). These trials did not show benefits of oils for milk production and emphasize the need for longterm studies when developing on-farm strategies for methane mitigation. }, issn = {1176-5283}, author = {Woodward SL and Waghorn GC and Thomson NA} } @conference {41668, title = {Supplementing mature cows with either cereal or lipid-based supplements had no effect on the post-partum anoestrous interval}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {329-333}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {A large scale retrospective study was undertaken in2005 on the impact of the policies for induction of early calving (either undertaken during study period, stopped in previous 2 seasons, or continuing to induce) and other factors on herd reproductive performance. Data was gathered from whole-herd pregnancy testing data and farm visit records, and electronic records from the LIC database. Data analysed included records from 3 consecutive seasons from 82 herds, and included 34,729 cows, 72,593 calvings, 237,884 individual herd test records and summary pregnancy test results for each herd for 3 seasons. Factors that significantly influenced herd reproductive performance were herd induction policy, season, herd predominant breed, 4 week submission rate, average milk protein percent at herd test within 60 days following the start of the breeding programme, and length of breeding programme (all P< 0.01). Induction usage was found to be declining over time, implemented at a later stage of the calving programme and unlikely to meet Code of Practice requirements, and under-reported to the LIC database. This large-scale epidemiologic study provides important information for herd owners, their advisors, and other scientists on herd reproductive performance.}, issn = {1176-5283}, author = {Meier S and Gore P and Minnee E and Thomson N} } @conference {41898, title = {Systems biology and metabolomics : Experimental and computational challenges}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {213-218}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {High-throughput technologies in the era of post-genomics provide new opportunities to investigate complex biological systems. Data can be collected for a system of interest at the level of gene expression, protein expression and metabolite concentration changes and then used for the assessment of interactions of molecules. However, the vast amount of information also poses challenges for data management, analysis, and interpretation. This paper aims to outline the technical complexity and the sources of variation in the technologies involved in molecular systems biology and computational strategies for data integration. }, issn = {1176-5283}, author = {Cao M and Koulman A and Pacheco D and Lane GA and Rasmussen S} } @conference {41888, title = {Teat spraying prior to calving may reduce the risk of heifer mastitis caused by Streptococcus uberis}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {168-171}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {Heifer mastitis caused by Streptococcus uberis is a significant problem for New Zealand dairy farmers. The mechanisms of infection in the pre-partum period have not been fully elucidated but prior research has established that the teats of dairy cows are contaminated with significantly higher numbers of S. uberis during the dry period as compared to during lactation. It is hypothesised that gross teat-end contamination by these bacteria before calving is a significant risk factor for the entry of bacteria through the teat canal and establishment of infection. Regular disinfection of the teats in the dry period was evaluated as a means to reduce teat-end contamination and consequently to decrease the likelihood of glands developing an infection. Two groups of 27 heifers were assigned to either a {\textquoteleft}sprayed{\textquoteright} or {\textquoteleft}not-sprayed{\textquoteright} treatment. The sprayed heifers were teat-sprayed with a commercial iodine-based post-milking teat sanitizer three times a week for the last three weeks before calving. Before commencement of the experiment, teat-ends were swabbed to determine pre-existing contamination with S. uberis, which averaged 610 colony-forming units (cfu). Prior to calving, S. uberis counts on teat-ends were 560 cfu for the sprayed group and 1775 cfu for the non-sprayed group (p = 0.06). Bacteriology of milk from each gland at the first milking showed that 4\% of glands of the sprayed heifers were infected with S. uberis compared with 11\% for the non-sprayed heifers (p < 0.05). At the first herd test, heifers in the sprayed group had a lower SCC (380,000 cells/ml) compared to the non-sprayed group (790,000 cells/ml), although due to the small size of the study, this difference was not significant. It was concluded that teat-spraying in the dry period could reduce teat-end contamination and consequently the proportion of glands infected by S. uberis at calving. }, issn = {1176-5283}, author = {Lopez-Benavides MG and Williamson JH and Lacy-Hulbert SJ and Cursons RT} } @conference {41672, title = {To induce or not to induce? Insights into important influences on dairy farmer decision making over induced calving}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {350-354}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {Between 1998 and 2004 a sire progeny test was run atthe Poukawa Research Farm in Hawke{\textquoteright}s Bay. Four ewe genotypes were used (Romney, East Friesian x Romney, Finn x Romney and Poll Dorset x Romney) with up to 900 ewes mated each year. Datawas collected on 4614 lambs born to 74 rams (an average of 62 progeny per ram). Rams used represented 13 different terminal sire and dual purpose breeds. Ewes were mated using AI or single-sire mated in the paddock for one cycle. Lambs were tagged and weighed within 24 hours of birth. At 12 weeks ofage, lambs were weighed and scanned for eye muscle dimensions from which eye muscle area was estimated. Data were analysed using a REML animal model taking account of repeat matings among parents, genetic relationships among animals and incorporating adjustments for fixed effects associated with year, ewe genotype and litter size. At a mean lambing percentage of 165\%, the mean birth weight across all sires was 4.91 kg and ranged between 4.21 and 5.46 kg for individual sires. The mean 12 week liveweightwas 29.8 kg and ranged from 26.5 to 33.1 kg for progeny from individual rams. There was a wide range in GR fat depth (mean 8.9 mm, sire range 6.9 to 12.3 mm) when corrected to a constant carcass weight of 18.3 kg. The top rams for liveweight were not necessarily top for other characteristics. Significant numbers of lambs are sold store at weaning on a liveweight basis and this makes it possible to place a value on pre-weaning growth. At $2/kgliveweight, the average lamb sired by the top ram for growth would be worth $66.20 and the progeny from the bottom ranked sire would be worth $53 - a difference of $13.20 per lamb. Assuming these rams had an active lifespan of 4 years and mated 80 ewes rearing 125\% per year, each ram would leave 400 progeny. At $13.20 per lamb the difference in value between the top and bottom ranked rams would be $5280. These results show the differences between rams and highlight the importance of using breeding values in the ram selection process.}, issn = {1176-5283}, author = {Blackett P and Compton CWR and Glassey C} } @conference {41901, title = {Urinary biomarkers of forage feeding from ESI-MS/MS fingerprinting: exploratory studies}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {230-235}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {The combination of metabolic profiling by a combination of broad-spectrum analytical methods and multivariate statistics offers new opportunities for obtaining a global over-view of metabolism. It also facilitates the discovery of metabolites which can serve as useful markers of biological processes or states ("biomarkers"). Fast liquid chromatography and electrospray ionisation mass spectrometry with collision-induced dissociation in an ion-trap (fast LC-ESI-MS/MS) has been applied to determine metabolic profiles of bovine urine samples. The samples were collected twice daily from groups of five lactating dairy cows grazing in four different forage management systems comprising different spatial and temporal allocations of ryegrass (Lolium perenne) and white clover (Trifolium repens). The data have been analysed by different multivariate statistical methods, and a number of candidate biomarkers of forage feed and diurnal processes have been identified. }, issn = {1176-5283}, author = {Lane GA and Fraser K and Cao M and Koulman A and Cosgrove GP and Death A} } @conference {41658, title = {The use of alternative therapies in racing thoroughbreds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {279-283}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {The use of alternative therapies (physiotherapy, chiropractic, etc) in the New Zealand (NZ) Thoroughbred appears to be common practice, despite the lack of scientific evidence to support their use in the species. It is unknown what treatments are being offered to these athletes, the types of problems alternative therapies are used for, if the {\textquoteleft}therapists{\textquoteright} providing the treatments are qualified, and if the horses seen by therapists are also under veterinary care. To obtain preliminary data on the use of alternative therapies in the NZ Thoroughbred horse a face to face survey was conducted with 23 trainers located in the Auckland and Manawatu regions of the North Island of NZ. The data collected represented 906 racehorses in training during the 2004/2005 racing season. Stables were categorized as small (less than 10 horses, n=8), medium (11-25 horses, n=8) and large (greater than 26 horses in training, n=7). The proportion of horses injured within each stable category was 21\%, 28\% and 33\% respectively. Nineteen trainers out of the 23 surveyed used at least one type of alternative therapy during the racing season, and 296 horses (33\%) had at least one exposure to alternative therapy. On average trainers spent $25,026 per year on veterinary treatments and $43,112 on alternative therapies. Eleven different types of alternative therapy were identified by trainers, with physiotherapy being the most commonly used (10 trainers), particularly by large (71\%) and small (63\%) stables. Eight stables used some form of alternative therapy on a monthly basis to treat 33\% of their horses in training, 4 on a weekly basis to treat 47\% of their horses and 3 on a daily basis to treat 44\% of their horses. Sixteen different alternative therapists were identified in this study, 7 had formal qualifications. The data collected indicated that the use of alternative therapies in the NZ Thoroughbred industry was widespread. }, issn = {1176-5283}, author = {Coleman HJ and Rogers CW and Gee EK} } @conference {41610, title = {Using a whole farm model to explore options for feed grown on-farm to achieve 1750 kg milksolids per hectare in the Waikato}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {29-34}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {Dexcel{\textquoteleft}s Whole Farm Model (WFM) is a computer model of a dairy farm that simulates individual cows and paddocks, with pasture growth driven by observed climate data and with management policies guiding decisions on a daily basis. The aim of the study was to design a farm system to produce 1750 kg milksolids (MS)/ha/yr from feed grown on-farm. An average predicted pasture growth curve was derived by initialising the WFM for a typical all-pasture Waikato farm (3 cows/ha) with "best practice" management policies and running the simulation for 29 years of Ruakura climate data. The model was then used with this average growth curve to design the high producing system. Pasture growth alone (17.3 t DM/ha) did not fulfil the feed requirement for the 1750 kg MS/ha scenario, with an overall feed deficit of 3.1 t DM pasture/ha. Improvements in ryegrass cultivars and N-fertilisers could be expected to increase pasture production by around 10\%, reducing the overall feed deficit to 1.6 t DM pasture/ha. These improvements together with irrigation at 2 mm/day over the three summer months (Dec - Feb) reduced the feed deficit to zero. Irrigation could be replaced by cropping between 11\% and 20\% of the farm in a rotation of annual ryegrass yielding 7 t DM/ha and maize yielding 22 to 28 t DM/ha respectively. }, issn = {1176-5283}, author = {Beukes PC and Clark CEF and Wastney ME and Palliser CC and Levy G and Folkers C and Lancaster JAS and Leydon-Davis C and Thorrold BS} } @conference {41929, title = {Variation in the New Zealand ram breeding industry ? results from the Poukawa progeny test}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {373-376}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {Between 1998 and 2004 a sire progeny test was run at the Poukawa Research Farm in Hawke{\textquoteright}s Bay. Four ewe genotypes were used (Romney, East Friesian x Romney, Finn x Romney and Poll Dorset x Romney) with up to 900 ewes mated each year. Data was collected on 4614 lambs born to 74 rams (an average of 62 progeny per ram). Rams used represented 13 different terminal sire and dual purpose breeds. Ewes were mated using AI or single-sire mated in the paddock for one cycle. Lambs were tagged and weighed within 24 hours of birth. At 12 weeks of age, lambs were weighed and scanned for eye muscle dimensions from which eye muscle area was estimated. Data were analysed using a REML animal model taking account of repeat matings among parents, genetic relationships among animals and incorporating adjustments for fixed effects associated with year, ewe genotype and litter size. At a mean lambing percentage of 165\%, the mean birth weight across all sires was 4.91 kg and ranged between 4.21 and 5.46 kg for individual sires. The mean 12 week liveweight was 29.8 kg and ranged from 26.5 to 33.1 kg for progeny from individual rams. There was a wide range in GR fat depth (mean 8.9 mm, sire range 6.9 to 12.3 mm) when corrected to a constant carcass weight of 18.3 kg. The top rams for liveweight were not necessarily top for other characteristics. Significant numbers of lambs are sold store at weaning on a liveweight basis and this makes it possible to place a value on pre-weaning growth. At $2/kg liveweight, the average lamb sired by the top ram for growth would be worth $66.20 and the progeny from the bottom ranked sire would be worth $53 - a difference of $13.20 per lamb. Assuming these rams had an active lifespan of 4 years and mated 80 ewes rearing 125\% per year, each ram would leave 400 progeny. At $13.20 per lamb the difference in value between the top and bottom ranked rams would be $5280. These results show the differences between rams and highlight the importance of using breeding values in the ram selection process. }, issn = {1176-5283}, author = {Muir PD and Thomson BC and Smith NB and Clarke JN} } @conference {41677, title = {Variation in the New Zealand ram breeding industry {\^u} results from the Poukawa progeny test}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {373-376}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {Between 1998 and 2004 a sire progeny test was run at the Poukawa Research Farm in Hawke{\textquoteright}s Bay. Four ewe genotypes were used (Romney, East Friesian x Romney, Finn x Romney and Poll Dorset x Romney) with up to 900 ewes mated each year. Data was collected on 4614 lambs born to 74 rams (an average of 62 progeny per ram). Rams used represented 13 different terminal sire and dual purpose breeds. Ewes were mated using AI or single-sire mated in the paddock for one cycle. Lambs were tagged and weighed within 24 hours of birth. At 12 weeks of age, lambs were weighed and scanned for eye muscle dimensions from which eye muscle area was estimated. Data were analysed using a REML animal model taking account of repeat matings among parents, genetic relationships among animals and incorporating adjustments for fixed effects associated with year, ewe genotype and litter size. At a mean lambing percentage of 165\%, the mean birth weight across all sires was 4.91 kg and ranged between 4.21 and 5.46 kg for individual sires. The mean 12 week liveweight was 29.8 kg and ranged from 26.5 to 33.1 kg for progeny from individual rams. There was a wide range in GR fat depth (mean 8.9 mm, sire range 6.9 to 12.3 mm) when corrected to a constant carcass weight of 18.3 kg. The top rams for liveweight were not necessarily top for other characteristics. Significant numbers of lambs are sold store at weaning on a liveweight basis and this makes it possible to place a value on pre-weaning growth. At $2/kg liveweight, the average lamb sired by the top ram for growth would be worth $66.20 and the progeny from the bottom ranked sire would be worth $53 - a difference of $13.20 per lamb. Assuming these rams had an active lifespan of 4 years and mated 80 ewes rearing 125\% per year, each ram would leave 400 progeny. At $13.20 per lamb the difference in value between the top and bottom ranked rams would be $5280. These results show the differences between rams and highlight the importance of using breeding values in the ram selection process. }, issn = {1176-5283}, author = {Muir PD and Thomson BC and Smith NB and Clarke JN} } @conference {41671, title = {Variation in yields of milk and milk solids in Holstein cows induced to calve prematurely}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {344-349}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {Milk production was compared between multiparous Holstein cows that were induced to calve and herdmates that calved spontaneously at approximately the same time in 88 dairy herds from Victoria and Tasmania. Yield averages for each herd were calculated for induced and spontaneously calving cows for milk volume, milkfat and protein during the first 120 days of lactation and for 305 days. Associations between induced and spontaneously calving groups for 305-day yields were described using linear equations. Slopes ranged from 0.82 (for milk yield) to 0.87 (for protein yield) and R2 values ranged from 0.84 to 0.88 (P<0.001). The average reduction in milk yield over the 88 herds was 366 litres (7\%). The estimated milk yield reduction for induced groups in herds where spontaneously calving contemporaries averaged only 3500 litres per 305 days was 40 litres (1.1\%) compared to an average estimated reduction of 915 litres (11\%) in herds averaging 8500 litres. Similar proportional reductions were calculated for 305-day yields of milkfat and protein. Collectively these results show that yield reductions following induced premature parturition are substantially higher in absolute as well as proportional terms in herds with higher milk yields. }, issn = {1176-5283}, author = {Jaques SA and Macmillan KL and Anderson GA and Morton JM} } @conference {41643, title = {Whole-body protein turnover in Merino sheep selected for wool and body growth}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {200-205}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {The objective of this research was to identify metabolites produced by commensal bacteria that enhance the integrity of the gastrointestinal barrier (GIB). The integrity of the GIB is mainly determined by the complexity of interactions between tight junctions of opposing epithelial cells of the GI wall. This was measured using an in vitrobioassay, consisting of a monolayer of intestinal epithelial cells grown on a membrane. The trans-epithelial electrical resistance (TEER) across this monolayer was measured to determine the strength of the tight junctions. Preliminary results showed that a commercial probiotic product caused an increase in TEER across non-differentiated and differentiated monolayers by 178 {\textpm} 61\% and 40 {\textpm} 9\%, respectively. The maximum increases in TEER obtained with conditioned media fractions (media fractions containing components secreted by the probioticproduct) was between 23 {\textpm} 6\% and 43 {\textpm} 4\%. The conditioned media fraction containing components less than 3 kDa accounted for the total activity of the whole conditioned media. Metabolite profiling ofactive conditioned media compared to inactive conditioned media using fast-LCMSMS identified numerousmetabolites that may be responsible for this positive effect. Future work will isolate the candidate metabolites and screen them for GIB enhancing activity both in vitroand in vivo.}, issn = {1176-5283}, author = {Li L and Oddy VH and Godwin I and Hegarty J and Nolan JV} } @conference {41882, title = {Wool keratins - the challenge ahead}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {133-139}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {Sheep wool is predominantly composed of keratin proteins. These comprise keratin intermediate filament proteins embedded in a matrix of smaller keratin associated proteins. As a result of polymorphisms and post-translational modifications, these proteins display many more family members than there are genes. Recent studies using improved gene expression, electron tomography and proteomic techniques have provided useful preliminary data on the association of keratins with certain fibre properties. Current research is quantifying keratin gene expression in the skin and the consequent wool protein compositional differences between breeds of divergent fibre and fleece characteristics. A detailed understanding of the control of keratin gene expression and fibre protein composition arising from these and other studies will provide the foundation for the development of novel high-value wool types, solubilised keratins for specialised cosmetic applications and reconstituted keratin polymers for biomedical applications. }, issn = {1176-5283}, author = {Plowman JE and Bryson WG and Yu Z-D and Gordon SW and Pearson AJ and Kelly RJ} } @conference {41546, title = {The AgriBase{\"O} farm location database}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {93-96}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {AgriBase{\texttrademark} is a national spatial farms database. It was launched in 1993 and now holds information on approximately 105,000 live (current) farms. Each distinct farm has a unique farm identifier - the Farm_ID. AgriBase holds key contact details for the farm, predominant farm type, overall size, animal numbers by stock class, planted areas for different orchard or crop types (including forestry), and the spatial coordinates of the farm usable within a geographic information system. Both government and private sector groups use AgriBase{\texttrademark} as a master index for all rural land holdings involved in some form of primary production. It has been used in exotic disease and pest investigations and responses, rescue helicopter missions, epidemiological research into human and animal health issues, development of environmental indicators, within-farm fertiliser planning, among others. AgriBase{\texttrademark} was extensively used during the February 2004 floods in the lower North Island to locate and contact affected farmers and survey the levels of damage. It is proposed that AgriBase{\texttrademark} has a central role to play in the development and delivery of food safety traceability and verification systems for New Zealand. Key Words: farm; database; Geographic Information System (GIS); food safety; traceability. }, issn = {1176-5283}, author = {Sanson RL} } @conference {41553, title = {Animal welfare in large dairy herds: a survey of current practices}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {127-131}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {To gain insight into the farm practices and animal welfare issues on large dairy herds, we conducted a postal survey (n = 132). The questionnaire covered four areas: demographics, stand-off practices, management during extreme weather, and races. Respondents managed 910 {\textpm} 466 (mean {\textpm} SD) milking cows during the 2003 season. When asked to identify the most important animal welfare problem on their farm, 73\% of the respondents named one of the following: lameness, disease, or nutrition/growth. Fifty-one percent of respondents used some form of stand-off area during periods of inclement weather. There are several management practices used with stand-off areas that are relevant to animal welfare including: provision of feed, shelter, space allowance, and surface type. During extreme winter and summer weather, a range of practices was used to manage cows, including changes in grazing patterns. For example, 61\% of respondents used paddocks closer to the milking shed and 40\% used sprinklers at the shed during hot weather. Finally, on average, cows walked 1.9 {\textpm} 0.8 km to the milking shed, and walking distance increased with the number of cows/farm. Farmers demonstrated awareness of animal welfare issues and implemented management practices that likely improve the well-being of their stock. KEYWORDS: animal welfare; dairy cattle; herd size; management practices. }, issn = {1176-5283}, author = {Tucker CB and Verkerk GA and Small BH and Tarbotton IS and Webster JR} } @conference {41544, title = {Applying traceability across an industry}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {88-90}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Livestock Improvement Corporation (LIC) has a world leading capability in individual animal recording of which MINDA is the product that is most often associated with traceability. MINDA annually handles many millions of transactions that relate to individual animals, herds, farms, and the people who are associated with them. Currently, it is primarily a dairy application but other species are represented. MINDA already captures data that are required for traceability (lifetime ID, birth, death, movements, health records) on a central database, and does so using a variety of tools that suit all customer profiles. LIC systems include a trace forward/back functionality, integrated with existing internal GIS systems.}, issn = {1176-5283}, author = {Purcell C} } @conference {41558, title = {Associations between Streptococcus uberis populations on farm races and climatic changes during a twelve-month period}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {153-156}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Streptococcus uberis is an important mastitis-causing pathogen in cows managed under pastoral conditions. The influence of environmental conditions on S. uberis ecology in dairy farms is unknown. To evaluate associations between climatic parameters and population levels of the bacterium on the farm, farm races were monitored for S. uberis levels on a fortnightly basis from November 2003 to November 2004 at the Dexcel Lye research farm. Higher S. uberis contamination was observed in races where cow traffic was frequent and lower in areas where usage was minimal. Highest S. uberis contamination occurred in the month of August (630 cfu/g) and lowest in January (2 cfu/g). Significant associations were observed between S. uberis levels and relative humidity (r = 0.6), soil temperature at a depth of 10 cm (r = -0.8), solar radiation (r = -0.7) and maximum air temperature (r = -0.7). Around 70\% of S. uberis clinical mastitis cases occurred in the non-lactating and calving periods, when S. uberis levels in races were above 100 cfu/g and solar radiation levels were low. It is suggested that weather conditions have a significant impact on the survival of S. uberis in the dairy farm environment. }, issn = {1176-5283}, author = {Lopez-Benavides MG and Williamson JH and Cursons RT} } @conference {41572, title = {Comparing feed allowances to inferred energy intake using data from a dairy grazing farm trial}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {225-230}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {The main objective of this research was to investigate whether calculating intake of dairy cows using equations to predict energy requirements provides a good alternative to conventional ways of estimating intake. The method was applied to data from the Dexcel Holstein-Friesian strain trial over three seasons. Feed intake per cow was calculated as the sum of the energy requirements for maintenance, milk production, pregnancy, growth and body tissue mobilisation using measured yields of milk, fat, protein and lactose, live weight and body condition score of cows and calf live weights. In order to compare the estimates of feed intake to the amount of feed offered, linear regressions of calculated (ME) intake (grouped by farmlet) on the amount ME offered per farmlet were performed by season. The relationship between ME intake and ME offered was weak in the first year, with a limited response to increasing the amount of feed offered. This was because all the cows were two-year-olds with lower live weights and milk yields and consequently lower feed intakes. In the subsequent two years of the trial, the relationship between ME intake calculated using the energy equations were 67\% and 72\%. The modern strains of dairy cows responded well to higher levels of feed offered, while the 1970s strain of New Zealand dairy cows failed to increase intake when offered diets of higher total ME. Our results show that energy prediction equations offer a viable and cheap alternative of estimating ME intake of lactating dairy cows. KEYWORDS: dairy cows; energy intake; strain comparison; efficiency. }, issn = {1176-5283}, author = {Pryce JE and Harris BL and Montgomerie WA and Jackson R and MacDonald KA and Glassey CB and Thorrold BS and Holmes CW} } @conference {41835, title = {Condensed tannins in birdsfoot trefoil (Lotus corniculatus) affect the detailed composition of milk from dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {283-289}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Feeding birdsfoot trefoil (lotus, Lotus corniculatus) to dairy cows increases milk solids production and reduces methane production relative to ryegrass pasture. This study has measured the affect of lotus and lotus condensed tannins (CT) on milk protein and lipid composition. The trial involved 32 Friesian dairy cows offered either good quality perennial ryegrass pasture or lotus. Half of the cows given each diet were drenched with polyethylene glycol (PEG) to inactivate the CT. A daily milk sample was collected from all cows prior to and towards the end of the treatment period. Gross milk fat and milk protein concentrations were similar for cows fed lotus or ryegrass. Neither feed, nor CT affected individual proteins in the milk with the exception of lactoferrin (Lf) where the CT in lotus increased concentrations (138 vs 76 mg/l; P < 0.01). Forage type affected the composition of fatty acids (FA) in the milk with cows gazing lotus having higher concentrations of de novo synthesised (C4:0-C15:0; 28.3\% vs 26.7\%; P < 0.01) and lower concentrations of pre-formed (C17:0 and longer; 34.5\% vs 39.0\%; P < 0.05) FA than those grazing ryegrass. The CT in lotus appeared to affect ruminal biohydrogenation of FA, decreasing the concentration of saturated FA in the milk fat, and increasing in the concentrations of the omega-3 FA (1.5\% vs 1.1\%; P < 0.01). Changes in the saturation and proportions of FA may affect processing characteristics and functionality of milk from cows fed lotus. CT in lotus may also provide potential new avenues for increasing milk value on-farm. KEYWORDS: detailed milk composition; Lotus corniculatus; condensed tannins. }, issn = {1176-5283}, author = {Turner S-A and Waghorn GC and Woodward SL and Thomson NA} } @conference {41528, title = {Corticosteroid treatment prevents the reduction in food intake and growth in lambs infected with the abomasal parasite Teladorsagia circumcincta}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {9-12}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Recent studies with Trichostrongylus colubriformis have provided some direct evidence to support the view that the major contributor to reduced production in gastrointestinal nematode infections is the host immune response, rather than damage from the parasite per se. However, it is unknown if this is also true for abomasal infections. Parasite na{\"\i}ve lambs were either trickle infected with Teladorsagia circumcincta L3 larvae; similarly infected and concurrently immuno-suppressed with the corticosteroid methylprednisolone acetate; immuno-suppressed only; or remained as controls. Immuno-suppression abrogated the reduction in intake and subsequent production losses and reduction in feed conversion efficiency associated with infection suggesting the damage caused by this abomasal parasite per se may have little detrimental effect on lamb productivity. These findings add weight to the view that components of the developing immune response are generally the cause of reduced productivity in infected lambs. They may have ramifications for the genetic selection of animals that are predisposed to mount a strong immune response. KEYWORDS: immuno-suppression; nematodes; intake; feed conversion efficiency; sheep. }, issn = {1176-5283}, author = {Greer AW and McAnulty RW and Stankiewicz M and Sykes AR} } @conference {41552, title = {The cost of alleviating the pain caused by the castration of beef calves}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {123-126}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = { The pain caused by husbandry procedures such as dehorning or castration is of concern to those with an interest in animal welfare. In the future farmers will be encouraged and perhaps obliged to provide analgesia for animals subjected to these procedures. In New Zealand in the last decade veterinarians have developed a service for disbudding dairy calves using the sedative xylazine and local anaesthesia and this has become popular with some dairy farmers. This paper reports a financial analysis of the impact to the individual farmer and nationally of using different forms of analgesia when castrating calves. Four scenarios and their costs were analysed: (1) the status quo ($0.28/calf); (2) the use of local anaesthesia with increased labour costs ($1.56/calf); (3) the use of local anaesthesia plus systemic analgesia with increased labour costs ($5.45/calf); and (4) the employment of a veterinarian to do the castration ($9.39/calf). National costs ranged from $160,000 to $5,368,700 ($10 to $351 per farm) for the four scenarios. The proposed scenarios were more expensive than the status quo but were still small relative to average total farm costs, i.e. $170,974 on New Zealand sheep and beef farms in 2001-02. These figures do not include any allowance for the cost of the inconvenience of having to organise husbandry activities around veterinary visits. Farmers may resist the imposition any of these 3 scenarios. In future the use of analgesics may become standard farm practice. }, issn = {1176-5283}, author = {Stafford KJ and Mellor DJ and Dooley AE and Smeaton D and McDermott A} } @conference {41530, title = {Development of an experimental approach to measure vitamin B12 production and utilisation in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {19-22}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Cobalt (Co) is required by ruminants to enable synthesis of vitamin B12 by rumen micro-organisms. Lack of quantitative information on the synthesis, absorption or utilisation of the vitamin has made determining nutrient requirement difficult. Two trials with sheep previously depleted of vitamin B12 and offered low Co diet (0.08 mg/kg DM) are described which attempt to overcome these problems. In the first, ewes were dosed with Co intra-ruminally at rates between 0{\textendash}1 mg Co/day. Responses in plasma vitamin B12 were proportional (P < 0.001) to the amount of Co infused. In the second trial, vitamin B12 was infused into the bloodstream via the jugular vein at rates between 0{\textendash}2500 nmol/day. Plasma vitamin B B12 plateau values were directly proportional (P < 0.001) to infusion rate. The rate of vitamin B12 infusion needed to sustain the critical plasma concentration of 370 pmol B12 /l was 5.02 nmol B12 /day, which together with estimated absorption from the basal diet gives a total requirement for absorption of 8.12 nmol B12 /day. This value is in agreement with data in the literature. The model approach, therefore, seems quantitatively robust. This approach, together with estimates of vitamin B12 flow from the rumen, will enable study of dietary factors that predispose to poor vitamin B12 production in the rumen and its absorption from the alimentary tract, and therefore to low animal vitamin B12 status. KEYWORDS: Co/vitamin B12; infusion; sheep; rumen; modelling. }, issn = {1176-5283}, author = {Ludemann MR and Sedcole JR and Sykes AR} } @conference {41826, title = {Differences in grazing behaviour and herbage intake between genotypes of Holstein-Friesian dairy cows grazing short or long swards}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {236-240}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {The objective of this work was to compare dry matter intake and grazing behaviour of different strains (S) of Holstein-Friesian dairy cows during early lactation. Three strains of different origin [two 1990{\textquoteright}s genotypes of Holstein- Friesian from Overseas (OS90) or New Zealand (NZ90) origin and a 1970{\textquoteright}s NZ Friesian (NZ70)] were offered low or high pre-grazing herbage mass (HM) (2100 vs 2800 kg DM/ha) at a common daily allowance (35 kg DM/cow) between September and November 2004. Pasture dry matter intake (IT) and digestibility (D) were determined using the n-alkanes methodology. Time spent grazing (GT) and ruminating (RT) were observed for 24 hours. Intake per empty body live weight unit (ILW) and rate of intake (IRATE) were calculated. There was a significant SxHM interaction (P < 0.001) for IT and ILW. IT was similar at low HM across strains, whereas at high HM, a lower IT was recorded for the NZ70 while it was higher for the OS90. At low HM, ILW was slighter lower in the OS90 than in the NZ90 (P = 0.06) while at high HM both NZ90 and OS90 showed a higher ILW. In vivo digestibility was similar across strains but was higher at high HM (P < 0.001). There was a significant SxHM interaction for GT (P < 0.01) with both NZ strains spending more time grazing at low HM, in contrast, GT was similar across strains at high HM. RT was higher for the OS90 strain than for both NZ strains (P < 0.05) and greater at high HM (P < 0.001). There was a significant SxHM interaction for IRATE (P < 0.05) with the NZ90 and OS90 strains showing similar IRATE at low HM but different at high HM. Results indicate a difference in the ability of the strains to adjust their grazing behaviour to different pre-grazing herbage mass. KEYWORDS: Holstein-Friesian; high-merit dairy cow; intake; grazing behaviour, herbage mass. }, issn = {1176-5283}, author = {Rossi JL and MacDonald KA and Thorrold BS and Hodgson J and Holmes CW} } @conference {41853, title = {Digestion kinetics of New Zealand native flax}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {367-371}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {This experiment compares the nutritive value of New Zealand native flax, Phormium tenax, by-products i.e. leaves (L), butts (B), thrash-stripped fibre (F) and green matter (G), with white clover (WC) via digestion kinetics derived from in vitro and in sacco incubations. The WC had a high nutritive quality (11.1 MJME/kg DM, CP 28\% DM), G a moderate (10.1 MJME/kg DM, CP 9\% DM), and L, B, F were of very low nutritive quality (< 8 MJME/kg DM, CP < 6 \% DM). After 24 hours, 96, 76, 47, 47, and 30 \% of the DM was degraded for WC, G, L, B and F, respectively (P < 0.001). The degradation rates (\%/h) of digestible DM were faster (P < 0.001) for WC (13) and G (11) than B (3.8), L (4.6) and F (2.7). Flax by-products had a net loss of ammonia after 2 (B), 4 (F and L) and 8 hours (G). The proportion of DM converted to VFA by 8 hours was 21 \%, and 14 \% for WC and G respectively, but only 9-10 \% for the other flax by-products (P < 0.001). The feeding model BestFeed{\texttrademark} predicted that G could grow a 500 kg bull at 0.8 kg/day and had potential as a supplement for pasture-fed animals. KEYWORDS: flax; Phormium tenax; in sacco; in vitro; digestion kinetics; nutritive value; forage ration, BestFeed. }, issn = {1176-5283}, author = {Litherland AJ and Layton DL and Burke JL and Corson DC and Peters JS} } @conference {41560, title = {Does ewe nutrition during pregnancy affect the metabolism of twin-born lambs?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {163-167}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {An insulin tolerance test was conducted on twin-born ewes born to dams offered sward heights of either 2 or 6 cm between day 64 and 132 of pregnancy in order to identify any alterations in the lamb{\textquoteright}s metabolism. Lambs were also categorised into groups according to birth weight (< 4.0 kg, light and > 4.0 kg, heavy). Changes in metabolism may have long term effects on growth and productivity. An insulin challenge (0.2 U/kg) was administered to ewe lambs at 8 months of age and their plasma insulin, glucose and cortisol responses were monitored. The plasma cortisol concentration of ewe lambs born to ewes offered 2cm sward height was significantly (P < 0.05) higher than ewe lambs born to ewes offered 6 cm sward height 50 minutes after the insulin challenge. No difference was found in the insulin or glucose response to the insulin challenge between dam sward height group (2 vs 6 cm). Birth weight had no effect on the insulin, glucose or cortisol response of the ewe lambs to the insulin challenge. These results show that both dam nutrition and lamb birth weight had little to no effect on the metabolic responses measured. These results suggest that lambs born to ewes offered a herbage sward height of only 2 cm or lambs with low birth weights may not show altered metabolism. KEYWORDS: lamb; insulin tolerance test; twins; ewe nutrition; metabolism. }, issn = {1176-5283}, author = {Corner RA and Kenyon PR and Stafford KJ and West DM and Oliver MH and Morris ST and Blair HT} } @conference {41532, title = {Does the ewe nutrition during pregnancy affect the behaviour of ewe lambs at 1 and 2 years of age?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {29-32}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {The effects of the dam{\textquoteright}s nutrition during pregnancy on her lambs{\textquoteright} behaviour in the days after birth has been examined but the longer term effects on lamb behaviour and mothering ability are not known. The behaviour of twin and triplet ewes born to ewes offered herbage with an average sward height of 2 or 6 cm from day 64 to 132 of pregnancy was recorded at 1 year of age in an arena test and at 2 years of age post lambing. A significantly (P < 0.05) greater proportion of the progeny born to dams offered 6 cm sward heights bleated in a high pitch during a 5 minute arena test. However there were no differences in minimum, median and maximum distance of the ewe from the observer or on the frequency of low- and high-pitched bleats. In addition there was no difference in the behaviour of twin- and triplet-born ewes in the arena test. At 2 years of age twin-born ewes had a significantly greater maternal behaviour score than their triplet-born counterparts. Ewe nutrition during pregnancy did not affect the maternal behaviour score of their ewe lambs after lambing at 2 years of age. These results suggest that feeding levels during pregnancy are less important than the birth rank in terms of the intergenerational effects on behaviour. KEYWORDS: ewe nutrition; lamb; behaviour; twin; triplet. }, issn = {1176-5283}, author = {Corner RA and Kenyon PR and Stafford KJ and West DM and Morris ST and Blair HT} } @conference {41569, title = {The drinking behaviour of dairy cows in late lactation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {209-214}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {The drinking behaviour of grazing cows was investigated in two studies with the purpose of determining the suitability of using water intake as a motivator for voluntary movement of cows within a pasture-based automatic milking system (AMS). In the first study 100 mixed-age Jersey cows in late lactation were observed for 48 h. Cows drank on average 2.4 times/24 h (range: 1-6) and usually alone or with one or two other animals. Although every cow drank at least twice during the 48 h, 31\% of cows recorded an interval between drinks > 24 h. Less than 1\% of drinking occurred between 2000 h and 0700 h. The second study compared the drinking behaviour of Overseas (OS) and New Zealand (NZ) Holstein Friesian cows that were either grazing pasture (GRASS) or fed a Total Mixed Ration (TMR). TMR cows drank more often (5.2 times/24 h) than GRASS cows (3.5 times/24 h, P < 0.001). Feed type altered the distribution of drinking with 76.8 \% of TMR cows drinking between 2000 h and 0700 h compared with only 24.5\% for GRASS. Water intake was also higher for TMR (73.0 L/cow/day) compared with GRASS (53.7 L/cow/day) animals. The studies showed that the individual nature of drinking behaviour would be aligned with the AMS objectives of distributed rather than batch milking. However, the small number of cows drinking during darkness when grazing indicates that water intake would need to be used in combination with other motivators to ensure a continuous flow of cows to the dairy. KEYWORDS: drinking behaviour; grazing; dairy cows; automatic milking. }, issn = {1176-5283}, author = {Jago JG and Roche JR and Kolver ES and Woolford MW} } @conference {41539, title = {Economic comparison of Holstein-Friesian strains}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {68-73}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {The objective of this research was to identify major determinants of net profit per cow. Data were from the Dexcel strain trial over three seasons, in which Holstein-Friesian cows were managed in groups of 12 to 20 cows in eleven farmlets. Milk returns were calculated from lactation yields of milk, fat and protein. Net profit per cow was calculated as the net return from milk sales plus sales of calves minus feed, fertility, health, shed and working expense costs. Annualised present values were derived using asset replacement theory and discounting to account for different numbers of years of data according to the year in which an animal entered the herd. Net replacement costs and average replacement returns were included where animals were replaced before the end of the trial. Partition analysis was used to identify indicators of cow profitability. Partition analysis recursively sub-divides data creating a tree of partitions. Each split is chosen to maximise the difference in profitability between branches of the split. Variables on which data could be partitioned included breeding values, Breeding Worth and traits measured in first parity. The key determinants of profitability were lactation yield of protein and fat, percentage of fat and Breeding Worth. When these variables were fitted to a multiple regression model where the response was annualised present value, the adjusted R2 was 52\%. KEYWORDS: asset replacement model; economics; dairy cattle. }, issn = {1176-5283}, author = {Pryce JE and Harris BL and Glassey CB and Montgomerie WA and Jackson R and MacDonald KA and Thorrold BS and Holmes CW} } @conference {41563, title = {The effect of condensed tannins in sulla (Hedysarum coronarium) on 4-methylphenol metabolism in the ovine gastrointestinal tract during late lactation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {178-181}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Twelve lactating ewes were surgically prepared with permanent arterio-venous catheters across the gastrointestinal tract at 1 week post partum. From week 3 to 6 of lactation, all sheep were fed fresh sulla (1500 g dry matter/day; condensed tannins (CT) 4.4 g per 100 g dry matter). Half the ewes were orally drenched (4 times/day) with polyethylene glycol (PEG) (160 g/day in water) to remove the effects of the CT whilst the remaining ewes received a water drench. At week 6, para-aminohippurate was infused for 7 h into the cranial mesenteric vein for measuring mesenteric and portal plasma flow and 4-methylphenol concentrations. The mesenteric and portal plasma flows were not affected (P > 0.05) by the treatments. The concentration of 4-methylphenol in the mesenteric artery (Control: 2.8 vs PEG: 9.0 {\textpm} 1.2 μg/ml) was lower (P < 0.01) in the control ewes. The net portal appearance of 4-methylphenol was higher (P < 0.01) in the PEG ewes (Control: -663 vs PEG: -1430 {\textpm} 159 μg/minute). These results establish that sulla CT reduced the portal flux and peripheral concentration of 4-methylphenol and it is likely that this was a consequence of reduced formation of that metabolite in the rumen due to lowered ruminal protein degradation in the CT-treated ewes. KEYWORDS: plasma net fluxes; gastrointestinal tract; 4-methylphenol; lactation; sheep. }, issn = {1176-5283}, author = {Roy NC and Fraser K and Lane GA and Sinclair BR and McNabb WC} } @conference {41834, title = {The effect of genotype on milk composition, milk value and dairy farm profitability}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {276-282}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {This study was conducted to determine the effect of genotype on milk composition, milk value and economic farm surplus (EFS). The trial included two high breeding worth ($BW) strains of either North American (OS90) or New Zealand (NZ) (NZ90) genetics, and one low $BW strain of NZ genetics (NZ70). Each strain was farmed under systems designed to provide total feed allowances of 4.5 to 7.0 t DM/cow/year. For two years (2001/2002 \& 2002/2003) monthly average milk yield and composition were determined for each of the 11 herds. A simulation model was used to calculate milk value using three product mixes. Using either the simulated values or actual values (paid by Fonterra 2002/2003) for milk and its components, milk value ($/litre and $/kg milksolids (MS)) and an EFS for each herd was determined. The OS90 strain produced milk with lower concentrations of fat and protein and higher protein:fat ratio than NZ70 or NZ90 strains. The effect of strain on milk price was unaffected by product mix. Milk value differed between strains irrespective of method of determination. Milk value expressed as $/kg MS was lowest for the NZ70 and highest (P < 0.001) for the OS90 strain. When expressed as $/litre milk value was highest (P < 0.001) for the NZ90 strain. Milk value expressed as $/kg MS was positively associated with protein:fat ratio whereas milk value expressed as $/litre was positively associated with MS concentration. Average EFS was greater for the NZ90 than the NZ70 strain and was least for the OS90 strain. The factors associated with EFS were MS production; milk value and milk composition had minimal impact. New Zealand{\textquoteright}s dairy cattle breeding programme has produced a strain of Holstein- Friesian with increased milk fat and protein concentration, an increased protein:fat ratio, and an associated increased milk value and increased EFS. In comparison, the OS90 strain which the current $BW index ranks as high as the NZ90, produced milk with higher value ($/kg MS) but resulted in lower EFS. Key words: milk price; milk value; milk composition; economic farm surplus. }, issn = {1176-5283}, author = {Thomson NA and Turner S-A and Glassey CB and Lopez-Villalobos N} } @conference {41571, title = {Effect of pre- and postpartum pasture feeding intakes on postpartum anoestrous intervals in dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {221-224}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Extended postpartum anoestrous intervals (PPAI) are the predominant source of infertility on New Zealand dairy farms. A 2 x 2 factorial design was used to investigate pre- and postpartum pasture feeding levels on PPAI. Sixty-eight multiparous Holstein-Friesian dairy cows due to calve in the first three weeks of the calving period were randomly assigned to a high (11.9 kg DM/cow/day) or low (4.8 kg DM/cow/day) pasture feeding intake for 29 {\textpm} 7.7 days pre partum. After calving, cows within each prepartum feeding level were assigned to a high (13.5 kg DM/cow/day) or low (8.6 kg DM/cow/day) pasture feeding intake for 35 days. At 35 days post partum, cows were grazed as a single group with pasture silage supplementation. Concentrations of progesterone were determined in milk samples collected on Mondays and Thursdays until cows were confirmed to have resumed oestrous cycles or until one week before planned start of mating. High intakes pre-calving increased (P < 0.05) the proportion of cows cycling by the third week postpartum (38 {\textpm} 8\%) compared with a low pre-calving intake (13 {\textpm} 6\%). There was a tendency (P = 0.07) for a reduced mean PPAI in the high (29.7 {\textpm} 2.6 days) versus low (33.4 {\textpm} 2.3 days) pre-calving intake treatments, among cows that initiated oestrous cycles during the experimental period. Post-calving intake did not affect PPAI (P = 0.4), nor was an interaction detected. Body condition score (BCS) at all time points in this study, including before treatments were initiated, was negatively correlated with PPAI (P < 0.05). In contrast, PPAI was not associated (P > 0.1) with changes in BCS during the pre- or post-calving periods, or with milk production characteristics. In this study, resumption of oestrous cycling post partum was strongly linked to pre-existing differences in BCS, and modified by pre-calving pasture intake, but not influenced by feeding intakes or milk production characteristics in early lactation. KEYWORDS: anoestrus; nutrition; dairy cow. }, issn = {1176-5283}, author = {Burke CR and Roche JR and Aspin PW and Lee JM and Taufa VK} } @conference {41527, title = {The effect of SF6 release rate, animal species and feeding conditions on estimates of methane emissions from ruminants}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {3-8}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {In New Zealand methane (CH4) emissions are estimated using the sulphur hexafluoride (SF6) tracer technique. This involves inserting a calibrated source of SF6 gas into the rumen. The technique does not measure CH4 directly but estimates emissions from the ratio of CH4 to SF6 in breath samples collected continuously from above the nose of each animal. Methane estimates obtained using this method tend to be more variable than measurements obtained using respiration calorimetry. The absolute release rate of SF6 from the rumen could contribute to this variation. Data were extracted from a database containing details of 22 separate New Zealand experiments where the SF6 technique was used to estimate CH4. Experiments were divided into four groups according to species and feeding situation, with each group analysed separately. Data were analysed using a linear mixed model with a fixed effect of SF6 release rate, and random effect of experiment. In indoor fed cattle and sheep daily CH4 production was positively related to SF6 release rate (P < 0.05) but there was no relationship between SF6 release rate and daily CH4 production in grazing animals. In grazing sheep and cattle there was no significant effect of SF6 release on CH4 emitted per kg DMI. In cattle kept indoors CH4/kg DMI was positively related to permeation tube flow rate (P < 0.05) but there was no significant effect of SF6 release on CH4 emitted per kg DMI in indoor fed sheep. KEYWORDS: methane; SF6 tracer technique; ruminants. }, issn = {1176-5283}, author = {Vlaming JB and Clark H and Lopez-Villalobos N} } @conference {41827, title = {Effect of slaughter group and sire on carcass composition and meat quality characteristics of Texel-sired lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {241-246}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {New Zealand meat companies are investigating lamb payment systems based on lean-meat yield and meat quality. Factors that affect these traits need to be determined. Carcass composition and meat quality data from 450 Texel-cross lambs (ewe and ram) were used to evaluate the effect of sire (two sires Property One, three sires Property Two) and slaughter group. Lambs reaching target slaughter weight first (38 kg and 35 kg for ram and ewe lambs respectively) were allocated to slaughter group one, with the remainder allocated to slaughter group two and slaughtered approximately 40 days later. The average carcass weight for both groups was 17.9 {\textpm} 1.51 kg. Carcass composition traits were adjusted for carcass weight, and meat quality traits were adjusted for pH. Carcass width at the thorax and gigot was narrower in slaughter group two (P < 0.001). Trimmed leg weight and total leg muscle weight were lower (P < 0.001), whereas total leg fat weight and muscle to bone ratios were higher (P < 0.001), for slaughter group two. Femur muscularity was higher in slaughter group two (P < 0.001) for Property One only. Warner-Bratzler shear values and measures of colour (L*, a* and b*) were higher (P < 0.001), whereas cooking loss was lower (P < 0.001), for the longissimus muscle in slaughter group two. In addition, sire within property was a source of variation (P < 0.001) for all carcass composition traits and meat quality traits, with the exception of pH. These results demonstrate that both slaughter group and sire (within a breed and property) are significant sources of variation in carcass composition and meat quality traits. As a result, these need to be taken into account when making management and breeding decisions for the supply of lambs to meat companies under any future payment systems based on yield and meat quality. KEYWORDS: lamb; carcass traits; sire. }, issn = {1176-5283}, author = {PL Johnson and Purchas RW and Blair HT} } @conference {41561, title = {The effect of sward height during pregnancy on the wool follicle and fibre characteristics of twin and triplet born lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {168-172}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Previous work estimating the impact of differential feeding of ewes during pregnancy, on lamb wool follicle development, has been done primarily with single- and twin-bearing ewes. The aim of this study was to compare the follicle development and fibre characteristics of twin- or triplet-born/reared lambs, born to ewes offered different sward height allowances during pregnancy and lactation. After pregnancy scanning, 186 twin- and triplet-bearing Romney ewes with 6 weeks wool growth, were randomly allocated to four different sward heights (2, 4, 6 and 8 cm). Within the first 24 hours of parturition ewes were transferred to one of two sward heights (4 and 8 cm). The wool and follicle characteristics of twin- (n = 65) and triplet-born (n = 63) ewe lambs were compared. Fleeces from triplet-born lambs were lighter (1.59 kg vs 1.82 kg, P < 0.05) and finer (32.7 μm vs 33.4 μm, P < 0.05) than those from their twin-born counterparts. Lambs born to ewes offered higher sward heights during pregnancy had increased loose wool bulk (P < 0.01). Although increasing sward height during pregnancy increased fibre diameter in twin-born lambs, there was no similar relationship for triplet-born lambs (P < 0.05). Sward height during pregnancy had no effect on secondary follicle number in twin-born lambs but, triplet-born lambs born to ewes grazed on the 4 cm sward tended to have significantly higher numbers of secondary follicles than those grazed on 6 cm (89.2 vs 66.0, P < 0.05). More work is necessary to determine whether this interaction has practical implications for breeding replacements. Nutritional treatments during lactation had no significant effects on lamb wool characteristics. KEYWORDS: feeding; nutrition; follicle development; wool bulk; wool characteristics. }, issn = {1176-5283}, author = {Sherlock RG and Kenyon PR and Morris ST} } @conference {41570, title = {Effects of feeding level for four weeks precalving on milk production is small and dependent on level of feeding in early lactation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {215-220}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {The aim was to quantify the relationship between pre- and postcalving level of feeding and their effect on milk production. Sixty-eight multiparous dairy cows were randomly allocated to two levels of pasture feeding (Low and High; 4.8 and 11.9 kg DM/day) for 29 {\textpm} 7.7 days precalving. At calving, cows were randomly allocated (within precalving levels) to two levels of pasture feeding (Low and High; 8.6 and 13.5 kg DM/day) for 35 days postcalving. Daily milk yields were recorded and fat, protein and lactose concentrations determined on 2 days each week for 5 weeks postcalving, and once weekly for an additional 10 weeks post treatment. Body condition score (BCS) at calving was 4.2 and 4.7 for precalving Low and High treatment groups, respectively. Precalving restriction reduced milk fat production by 8.4\% during the first five weeks postcalving, but these differences were not evident subsequently. Postcalving feed restriction reduced yields of milk, fat and protein by 25, 21 and 28\%, respectively, during the first five weeks postcalving. Decreased (P < 0.05) yields of milk, fat and protein (12, 10 and 9\%, respectively) were also evident for ten weeks after the feed restriction finished. There was a trend towards a treatment interaction (P = 0.13) in milksolids (MS) production during the first five weeks of lactation between pre- and postcalving level of feeding. High- High cows produced 7.1 kg more MS than Low-High cows, but there was no effect of precalving level of feeding in cows that were restricted postcalving. Results confirm that level of feeding postcalving influences the milk production effect of precalving feeding. Nevertheless the effect of precalving energy intake on postcalving milk production is small. KEYWORDS: transition cow; pasture; dry matter intake. }, issn = {1176-5283}, author = {Roche JR and Kolver ES and Lee JM and Aspin PW and Burke CR and Taylor P and Napper AR} } @conference {41828, title = {Effects of level of current during lamb carcase electrical stimulation on post-mortem muscle changes and meat quality}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {247-251}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {A study was conducted using 60 lamb carcases to examine the effectiveness of a new type of stimulation system for improving meat quality of lamb carcases. There were 3 treatment groups {\textendash} control (no current), low current (400 mA) and high current (800 mA). The duration of stimulation was 35 seconds, 20 minutes after death. The stimulation treatments both significantly increased the rate of pH decline and caused an increase in the redness of the longissimus thoracis et lumborum muscle. There was no significant reduction in shear force due to stimulation, but ageing for 4 vs 2 days significantly (P < 0.001) decreased shear force by on average 12.6 N. There were no significant effects of stimulation on sensory traits, but, as for shear force, ageing significantly (P < 0.001) improved tenderness (60 vs 65 on a 0-100 scale). The lack of effect of stimulation may have been due to the high initial tenderness and liking scores of the control samples. These high values occurred in spite of a chilling rate under which cold-induced toughness, and, hence, low tenderness and liking scores, would have been expected. KEYWORDS: lamb; electrical stimulation; eating quality. }, issn = {1176-5283}, author = {Hopkins DL and Shaw FD and Baud S and Walker PJ} } @conference {41555, title = {The effects of once a day milking on mastitis and somatic cell count}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {137-142}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {A four-year study examined the effect of once a day (OAD) milking for complete lactations on mastitis and milk quality. The study comprised two herds of Jersey cows and two of Friesian cows, milked either OAD or twice a day (TAD) for a total of 4 lactations. Prevalence of intramammary infection (IMI) was determined by isolation of mastitis pathogens from quarter foremilk samples, collected aseptically at calving, mid lactation and at drying off. In the second and third years of the study, at drying off, cows milked OAD had three times as many (P < 0.01) quarters with IMI by major mastitis pathogens compared with TAD cows. Across all pathogens and years however, prevalence of IMI was not significantly or consistently higher for cows milked OAD compared with TAD. The somatic cell count (SCC) for uninfected cows milked OAD was approximately double that for TAD milked cows although this difference was only significant (P < 0.05) after the first 1-2 months of lactation had elapsed. Cows with minor or major pathogen infections also showed an approximate doubling of the SCC if milked OAD. Results suggest that milking OAD consistently increases the individual cow SCC but does not significantly increase prevalence of mastitis. KEYWORDS: once daily milking; mastitis; SCC; milk quality; milking frequency. }, issn = {1176-5283}, author = {Lacy-Hulbert SJ and Dalley DE and Clark DA} } @conference {41838, title = {Estimation of lactation persistency in crossbred grazing dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {300-305}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Lactation persistency is commonly referred to as the rate of decline in daily yield after the peak of lactation and can be measured in different ways. The objective of this study was to calculate different measures of persistency for milk traits and estimate the correlations between parameters of the lactation curve in crossbred cattle. Herd test records of milk, fat, protein and lactose from 810 first lactation cows were used to obtain individual lactation curves using a mixed model fitting six knots splines. The model included the fixed effects of contemporary group (year-calving week), sire, age at calving (linear and quadratic) and an average spline and the random effect of cow-spline interaction. All cows were in their first lactation, second cross Friesian x Jersey from a crossbreeding experiment established for quantitative trait loci identification. Persistency was measured in three different ways: P1, slope of the line fitted using linear regression of daily yield on day of lactation from day 60 to day 220; P2, the area under the lactation curve from day 121 to 180 divided by the area under the curve from day 1 to 60; and P3, the 240-day lactation yield divided by peak yield multiplied by 240. Correlations between measurements of persistency ranged from 0.24 to 0.81 and were significantly different to zero (P < 0.001). Correlations between lactation yield and measurements of persistency ranged from -0.43 to +0.33 and were significantly different to zero (P < 0.01). These results indicate that measurements of persistency are not invariant and highlight the need to calculate persistency in a more consistent way. When cows were classified for persistency P2 of fat plus protein, cows of high persistency (top 25\%), compared with cows of low persistency (bottom 25\%), had significantly (P < 0.05) more days in milk, higher total yields of milk and its components, lower peak yields, later day of peak yield and lower rate of decline in daily yield from day 60 to day 220 (P1), but similar 240-day total yield of fat and protein. Farming cows of high persistency may be an alternative to reduce farm investments in peak notes and risks of metabolic problems and reproductive failures. KEYWORDS: lactation persistency; milk yield. }, issn = {1176-5283}, author = {Lopez-Villalobos N and Spelman RJ and Harris BL and Stanley G and Harcourt S} } @conference {41536, title = {Exploiting cow genotype to increase milk value through production of minor milk components}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {53-58}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Milk value could be increased on-farm by supplying milk with enhanced concentrations of minor compounds that have bioactive properties. Compounds of interest in this study were the whey proteins lactoferrin (Lf) and lactoperioxidase (LP), and milk fatty acids; particularly conjugated linoleic acid (CLA) and omega-3 fatty acids. Mixed genotype cows (20 Friesian, 20 Jersey and 20 crossbred) were sampled to determine the effect of cow genotype and age on Lf concentration, Lf yield and LP activity at 4 times during the season. In milk fat, concentration of CLA and omega-3 fatty acids were determined twice during the season. Cow genotype had no effect on Lf concentration but age did (P < 0.002), with 4-year and older cows producing greater concentrations in milk than 3 year old cows. For harvesting Lf, Friesian cows would be the most profitable, with the greatest Lf yields, particularly in mid-late lactation. The highest LP activity levels throughout lactation were demonstrated in Jersey milk. In milk fat, Friesian cows produced milk of a putatively healthier profile, with greater concentrations of unsaturated fatty acids, CLA and omega-3 fatty acids. Key words: milk value; cow genotype; lactoferrin; lactoperoxidase; conjugated linoleic acid; omega-3 fatty acids. }, issn = {1176-5283}, author = {Back PJ and Thomson NA} } @conference {41850, title = {Factors affecting methane production in Friesian x Jersey dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {352-355}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Methane production was measured in 301, 3-year-old Friesian x Jersey dairy cows, during summer 2004 in stage one of a project to define phenotypes for quantitative trait loci (QTL) mapping and to investigate the relationships between CH4 and milk production. Animals were allocated into four groups and their methane production was measured during four days. Feed intake was estimated by the alkane technique and by prediction equations. Correlations between the alkane technique and prediction equations were all less than 0.37, but correlations amongst the prediction equations were greater than 0.61. Daily CH4 output varied from 210 to 498 g and averaged 332 g. Dry matter intake averaged 19.3 g/kg DM. Milk production and live weight gain were negatively related to CH4 production per kg dry matter intake. Sire was not found to have a significant effect on CH4 output per kg of dry matter; however, only six sires are represented in the trial. The CH4 output recorded in the current study was within the ranges observed in other studies and was repeatable between days. High quality data were generated for the QTL study. KEYWORDS: methane; herbage intake; alkanes; dairy cows. }, issn = {1176-5283}, author = {McNaughton LR and Berry DP and Clark H and PinaresPatino C and Harcourt S and Spelman RJ} } @conference {41833, title = {Factors influencing milk harvesting efficiency in an automatic milking system}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {271-275}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Maximising milk harvested per robot is an important goal of pasture-based automatic milking systems (AMS). Results are presented from an analysis of 2937 cow milkings in a year-round milking system during January 2003 at the Dexcel Automatic farm (average herd size = 75 cows). Each cow milking was classified as OK (yield > 80\% of expected yield, EY), Yield Carry Over (YCO, 20\% < yield < 80\% EY), or Failed (F, yield < 20\% EY). The time and duration (from entry to exit from crate) of each cow milking was determined, as well as milk yield, and from these milk harvesting rate was calculated. There were an average of 95.8 cow milkings/day, average milking frequency was 1.13 milkings/cow/day (range 0.9 {\textendash} 1.9 milkings/cow/day). Eighty-four percent of milkings were classified as OK, 8.9\% as YCO and 7.1\% as F (after which the cow was returned to the yard for another attempt). Milking times {\textpm} SD (F = 3.76 {\textpm} 2.57, YCO = 7.63 {\textpm} 3.31, OK = 10.07 {\textpm} 4.09 minutes/event) and milk harvesting rate (F = 0.09, YCO = 0.76 and OK = 1.37 kg/minute) suggest that failed milkings were costly in terms of time. The data show potential for improving the 24 h milk harvest per AMS through cow selection, a more consistent flow of cows through the AMS and technological improvements. KEYWORDS: milk harvesting efficiency; automatic milking systems; grazing; dairy cows. }, issn = {1176-5283}, author = {Davis KL and Jago JG and Wieliczko R and Copeman PJA and Bright K and Woolford MW} } @conference {41851, title = {Feeding maize silage to dairy cows : implications for methane emissions}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {356-361}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Maize silage was used on 25\% of New Zealand dairy farms in 2003/2004, with 26\% of these farms feeding 2 t DM/ha as maize silage. The nutritional value and animal responses to maize silage fed with pasture are well defined, but its impact on rumen methane emissions is not. In an 11-day indoor feeding trial, 32 Friesian dairy cows in mid lactation were fed ad libitum pasture with 0, 12, 24 and 36\% of the dry matter (DM) intake supplied by maize silage. Pasture and maize silage intakes, milk production and methane emissions were measured. Half of the cows in each treatment group were given intra-ruminal slow release monensin capsules. Total DM intakes were similar for all feed treatments. As maize silage intake increased, milksolids (MS) production decreased linearly from 1.73 (pasture only) to 1.46 kg/day (P = 0.0043, SED = 0.09) and methane emissions increased from 16.3 to 19.0 g/kg DMI (P = 0.0061, SED = 1.03). Increasing proportions of maize silage in a pasture-based diet increased methane emissions from lactating dairy cows. These effects were alleviated by monensin. KEYWORDS: dairy cows; methane emissions; milk production; perennial ryegrass; maize silage. }, issn = {1176-5283}, author = {Waugh CD and Clark DA and Waghorn GC and Woodward SL} } @conference {41832, title = {Further testing of the effect of a calpain-1 variant on meat tenderness in cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {266-270}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {We have previously reported that a single-nucleotide polymorphism (SNP) on the large subunit of micro-calpain (the calcium-activated neutral protease-1 gene) is associated with differences in tenderness, as measured in cooked steaks from the longissimus dorsi of animals from the AgResearch Jersey-Limousin Beef DNA-marker trial. The effect was significant at the intermediate stages of the tenderising process and had little effect on initial or ultimate tenderness, so that tenderising was accelerated in animals having one or two copies of the favourable variant. We have now analysed tenderness and genotype data from 310 additional animals, comprising Hereford-cross and pure Angus breeds slaughtered under varying conditions of electrical stimulation and aged at a range of temperatures. Results in all cases support the original finding: animals with two copies of the {\textquoteleft}C{\textquoteleft} allele (the SNP on Exon-9 encoding alanine at amino acid number 316) have more tender meat (decreased shear force) at the intermediate stages than animals with two copies of the {\textquoteleft}G{\textquoteleft} allele (encoding glycine). Combining measurements from three intermediate cook times, mean shear forces from {\textquoteleft}CG{\textquoteleft} were less than from {\textquoteleft}GG{\textquoteleft} genotypes by 0.80 {\textpm} 0.29 kg (P < 0.01), and mean shear forces from {\textquoteleft}CC{\textquoteleft} were less than from {\textquoteleft}CG{\textquoteleft} genotypes by 1.19 {\textpm} 0.36 kg (P < 0.001). These results show that a genotype substitution from {\textquoteleft}GG{\textquoteleft} to {\textquoteleft}CC{\textquoteleft} is associated with a difference in shear force in longissimus dorsi steaks of approximately 20\% at intermediate aging times. KEYWORDS: cattle; meat; tenderness; micro-calpain; SNP. }, issn = {1176-5283}, author = {Cullen NG and Morris CA and Veenvliet BA and Hickey SM and Dobbie PM and Wilson T} } @conference {41848, title = {Generating value from differentiated milk products}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {344}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {

There is an identified consumer demand for foods that promote health and wellness. To address this need Fonterra is developing products with proof of efficacy for a range of clinical indications, providing health and wellness to customers through novel customer solutions derived from milk. Novel approaches to generating and processing these foods are necessary to manufacture products with this proven efficacy. These health benefits{\textellipsis}

}, issn = {1176-5283}, author = {South C} } @conference {41830, title = {Is goat meat acceptable to Japanese youth? The first goat meat taste survey in Japan}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {256-260}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Two sensory evaluations of goat meat were carried out to examine the acceptance of goat meat by Japanese youth. The first test used 172 university students to examine the preference between loin and hind leg of domestic goat. The second test employed 35 university students to rate taste differences between loin and fillet. The sensory analysis between loin and hind leg showed that {\textquoteleft}chewiness{\textquoteright} in goat meat was highly rated. Also loin meat was relatively highly evaluated in comparison with hind leg meat. Fillet meat obtained slightly higher evaluation in comparison with loin meat. Due to the expense of goat meat at retail outlets in Japan, New Zealand could have an advantage of shipping loin and fillet goat meat to meet the future demand by Japanese youth. KEYWORDS: goat; meat: sensory test; Japan. }, issn = {1176-5283}, author = {Ozawa T and Lopez-Villalobos N and Blair HT} } @conference {41549, title = {How can we make better use of traceability?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {107-112}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Traceability is rapidly becoming a way of doing business in the food industry. Companies have a choice of regarding it as a compliance requirement or to utilise the newly available technologies to capture data regarding full supply chain and product attributes. By having the relevant data available it can be analysed to unlock previously unavailable information regarding business processes and attributes while providing compliance traceability by default. Depending on this choice, traceability can either be a compliance cost or it can add value to an enterprise. KEYWORDS: value traceability; attribute traceability; compliance. }, issn = {1176-5283}, author = {Nortje GL} } @conference {41543, title = {Identification of cattle and deer as a movement traceability aid in the eradication of bovine tuberculosis}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {85-87}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {The Biosecurity (Animal Identifications Systems) Regulations 1999 oblige the owners of cattle and deer to use an identification (ID) system, that has been approved under those regulations, when moving cattle or deer aged over 30 days of age. The use of such an identification system is required for the purposes of the National Bovine Tuberculosis Pest Management Strategy (NBTPMS). It involves the permanent unique identification of cattle and deer to the herd from which they are first moved after 30 days of age. The ID technology currently employed consists of optically read ear-tags. Two approved ID systems are currently in place. One is operated by the Animal Health Board (AHB system) and is mostly used by beef and deer farmers. The Livestock Improvement Corporation provides a system (the LIC MINDA system) that has many additional identification functions required within the dairy industry. KEYWORDS: deer; cattle; identification; movement; disease control. }, issn = {1176-5283}, author = {Hancox N} } @conference {41829, title = {Identifying opportunities to add value to the New Zealand beef industry : a modelling approach}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {252-255}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {A model of the New Zealand beef value chain, from conception to export, was constructed. The model is parameterised at the national level so that issues and opportunities within the beef industry can be examined at a high level by researchers and industry participants. Working with numerous key informants from throughout the beef industry, the researchers developed a conceptual model of the beef value chain and then constructed the model in a spreadsheet. The model is capable of modelling changes in farm practice, market situations and the industry structure. This model and a range of scenarios have been demonstrated to a range of beef industry participants facilitating considerable debate. To illustrate the power and value of the model in evaluating change and facilitating debate within the beef sector, three scenarios are presented and compared with the status quo. KEYWORDS: value chain; scenario evaluation; beef; model. }, issn = {1176-5283}, author = {McDermott A and Dooley AE and Smeaton DC} } @conference {41559, title = {Immunity in pregnant ewes following a live-dead vaccination and infection with Salmonella Brandenburg}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {157-162}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = { The aim of this study was to investigate the efficacy of a combined live{\textendash}dead vaccination protocol to protect sheep against Salmonella Brandenburg infection. Thirty ewes were randomly divided into two groups, one of which was vaccinated and the other acted as a control. The vaccinated group received a live modified Salmonella Typhimurium vaccine (given by eye-drop) followed 4 weeks later by a sub-unit preparation derived from S. Brandenburg (given subcutaneously with the adjuvant Quil A). Following challenge with wild type S. Brandenburg (4 weeks after the booster), 43\% of the ewes aborted in the vaccine group as compared with 53\% of the controls. However, a higher mortality rate was found in the vaccine group (43\% vs 20\%). Using an enrichment/selection procedure, S. Brandenburg was detected in the faeces of all challenged animals until 3 weeks post challenge. By 6 weeks and 9 weeks post challenge approximately 50\% and 30\% of animals respectively were shedding, irrespective of treatment. Following administration of the live primary and subunit (secondary) vaccines, levels of total IgG, IgG1 and IgM antibody (measured with an indirect ELISA) were significantly increased in comparison with the control group (P < 0.01). The cell-mediated immune response (interferon gamma from whole blood cultures) was also enhanced following use of the live attenuated vaccine (P < 0.01), but was much less pronounced after boosting with the subunit vaccine and following challenge. In summary, vaccination evoked immune responses but did not give protection to experimental infection with S. Brandenburg.}, issn = {1176-5283}, author = {Li H and McFarlane RG and Amoafo OY and Zhang XZ} } @conference {41534, title = {Impact of farm management decision rules on the production and profit of different strains of Holstein-Friesian dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {40-45}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Management decision rules ({\textquoteleft}old{\textquoteright} rules) have been used at the Dexcel No. 2 Dairy Farm to remove subjectivity from the management of farm systems research and have also been promoted to the dairy industry. A trial involving these rules where three strains of Holstein-Friesian (HF) cows were compared has completed its third season. The trial included two high breeding worth (BW) strains of either North American (OS90) or New Zealand (NZ90) genetics, and one low BW strain of NZ genetics (NZ70). Under the {\textquoteleft}old{\textquoteright} rules the OS90 cows had fewer days in milk than the other two strains, mainly because they were dried off earlier due to their lower body condition score (BCS). In the third lactation {\textquoteleft}new{\textquoteright} rules were applied that allowed cows at the higher feed allowances to be dried off later (but at the same BCS) than would have been allowed under the {\textquoteleft}old{\textquoteright} rules. For the herds receiving the higher feed allowances, this change resulted in increased days in milk (NZ90 + 2 days; OS90 + 17 days) more milksolids (MS) per cow (NZ90 +2 kg; OS90 +21 kg), and more feed required (NZ90 + 10 kg; OS90 + 157 kg DM/cow) with all herds reaching target BCS by their next calving. It is calculated that this reduced the difference in economic farm surplus (EFS) per ha between the NZ90 and OS90 from $488 to $219. These results indicate the need to alter management rules to get the best performance from North American HF genetics. KEYWORDS: Holstein-Friesian; body condition score; drying-off decision rules. }, issn = {1176-5283}, author = {MacDonald KA and Thorrold BS and Glassey CB and Holmes CW and Pryce JE} } @conference {41852, title = {Impact of monensin on methane production and performance of cows fed forage diets}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {362-366}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Monensin is an ionophore used to increase the efficiency of feed utilisation when grain-based rations are fed to beef cattle, but it can also lower energy losses to methane. A series of feeding experiments has been undertaken to measure the impact of monensin on methane production by dairy cows fed ryegrass-dominant pastures alone or with white clover, or maize silage. Methane production measured from 15 sets of identical twin cows fed indoors was reduced by 9\%, from 16.9 to 15.3 g/kg dry matter (DM; P < 0.01), and remained 10\% lower (P < 0.05) than Controls 72 days after the monensin capsule was given. When pasture was substituted with maize silage at 12, 24 and 36\% of DM intake, monensin reduced methane (g/kg DM) by 1, 6.5 and 10.5 \% respectively (P = 0.05). However, methane emissions were not affected in cows fed pasture with white clover at 15, 30 or 60\% of DM intake. Although monensin provides an important opportunity for methane reduction, the data demonstrate a need to understand reasons for variable responses to treatments under differing nutritional regimes. The added benefits of improved feed efficiency and reduced bloat suggest further investigation of monensin for forage fed ruminants is warranted. Keywords: monensin; dairy cows; methane; pasture; white clover; maize silage. }, issn = {1176-5283}, author = {Van Vugt SJ and Waghorn GC and Clark DA and Woodward SL} } @conference {41535, title = {Influence of dairy cow genotype on milksolids, body condition and reproduction response to concentrate supplementation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {46-52}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Responses to supplementary feeding overseas (OS) and New Zealand (NZ) Holstein-Friesian (HF) cows were investigated over two years using 57 cows receiving a high pasture allowance and 0, 3 or 6 kg concentrate DM/cow/day. Cows of similar Breeding Worth ($BW) grazed as a single herd and were individually fed a grain-based supplement. Important production genotype x diet interactions of a scaling nature were detected. Across all supplementation levels, OS cows gave a greater (P < 0.05) linear production response than NZ cows (74 vs 37 g MS/kg concentrate DM; 1.22 vs 0.67 kg milk/kg concentrate DM consumed, respectively), but gave a similar response in live weight and condition score gain during lactation per kg of concentrate DM consumed. However, because OS HF appeared to have a larger relative feed deficit than NZ HF when fed ad libitum on pasture, OS HF maintained a lower body condition score throughout lactation and produced less milksolids (as a \% of live weight). Current supplementary feeding decision rules which recommend reducing supplementary feed use when abundant pasture is available remain appropriate for high $BW NZ HF cows. However, reasonable responses to high-energy supplements will continue to be obtained from high $BW OS HF cows, even when pasture supply appears adequate to meet cow requirements. Use of indicators of relative feed deficit such as milksolids as a \% of live weight and body condition score, may be a better guide to predicting the production response to supplementation, rather than decision rules based on genotype. KEYWORDS: Holstein-Friesian; genotype; supplements. }, issn = {1176-5283}, author = {Kolver ES and Roche JR and Burke CR and Aspin PW} } @conference {41529, title = {Lamb survival: a new examination of an old problem}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {13-18}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {The overall aim of this project is to identify genetic markers for lamb survival. This paper reports the results from the first stage of the investigation aimed to identify the primary causes of lamb death from parturition to three days of age for highly fecund flocks. Flocks in the study consisted of 9 breeds and 12,000 breeding ewes and were located in New Zealand regions; Southland, Otago and Manawatu. All lambs were tagged and identified to their dam and sire. Lambs dead at birth and up to three days of age were collected (n = 1529), weighed, measured and examined by post mortem to determine cause and time of death. Primary causes of lamb death included: dystocia, starvation/exposure, amnion over nose, organ rupture, disease, and unknown. The mean mortality rate from birth to weaning for the 20 flocks studied was 14 {\textpm} 0.6\% (SEM) in singles, 16 {\textpm} 0.3\% in twins and 29 {\textpm} 0.6\% in triplets. The study showed that the predominant primary cause of lamb deaths from parturition to three days of age was dystocia (difficult births). The dystocia rate was highest for dead single lambs (57 {\textpm} 4.2\% SEM) (P < 0.05), where there was an unexpectedly high incidence for dystocia for dead twin (46 {\textpm} 1.7\% SEM) and triplet lambs (48 {\textpm} 2.3\% SEM). This suggests that dystocia as a primary cause of lamb death may be underestimated within highly fecund sheep flocks. The high death rate from dystocia in twin and triplet lambs has not been previously reported and is currently under further investigation. KEYWORDS: lamb survival; dystocia; post-mortem; cause of death; mortality; genetic; phenotypic. }, issn = {1176-5283}, author = {Kerslake JI and Everett-Hincks JM and Campbell AW} } @conference {41843, title = {Mathematical modelling of anoestrus in dairy cows and the linkage to nutrition}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {324-328}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Postpartum anoestrus is a major reproductive problem in New Zealand dairy cows and its duration is related to the nutrition levels both pre and post calving. However, the mechanistic details of this relationship are largely unknown. A better understanding of the interactions between nutritional status, and the levels of the reproductive hormones controlling follicle development and ovulation is needed. A mathematical model consisting of a set of interactive nonlinear differential equations and describing the dynamics of the interactions among luteinising hormone (LH), follicle stimulating hormone (FSH) and oestradiol was developed. The model depicts oestradiol profiles generated by individual follicles from the first follicular wave after calving until ovulation, and changes in LH pulsatility leading to the first pre-ovulatory surge are also produced. The robustness of the model was ascertained from iterative processes, and it was also checked against existing experimental data so as to mimic observed changes in hormone levels. It was shown that two mathematical parameters which control: i) the speed of changes in the feedback of LH activity to oestradiol; and, ii) the sensitivity of the ovarian response to LH, have the greatest effect on duration of anoestrus. KEYWORDS: mathematical model; anoestrus; dairy cows; nutrition; oestradiol; LH; FSH. }, issn = {1176-5283}, author = {Smith JF and Soboleva TK and Peterson AJ and Pleasants AB and Chagas LM and Burke CR} } @conference {41847, title = {Meat industry by-products : a cunningly disguised opportunity}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {340-343}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {A pharmaceuticals division was first established in a New Zealand (NZ) meat company by Richmond Limited in mid 2001. This new division was a first in Australasia and had the stated objective of adding value to a range of relatively low-value by-products. At that time the supply of by-products throughout the meat industry in NZ was generally characterised by: {\textbullet} low prices; {\textbullet} low level of attention; {\textbullet} low levels of enthusiasm; {\textbullet} lack of market knowledge. This presentation will attempt to: {\textbullet} describe, in general terms, the establishment of a pharmaceuticals division as an integral part of a meat company; {\textbullet} describe the process of establishing relationships between suppliers and customers; {\textbullet} highlight areas of particular strengths and weakness in the pharmaceuticals arena for the NZ meat industry; {\textbullet} make some observations about the medium and longer term prognosis for the industry, in its widest sense. }, issn = {1176-5283}, author = {Rogerson A} } @conference {41562, title = {Milk production in East Friesian-cross ewes lambing year round}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {173-177}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Milk production of groups of East Friesian cross ewes lambing at intervals of 73 days (i.e., five times per year: August (n = 21), November (n = 29), January (n = 13), March (n = 14) and June (n = 14)) was measured on alternate days in the first week post partum and at weekly intervals for nine weeks. Ewes with single and twin lambs were enrolled if they safely delivered the appropriate number of lambs indicated by previous scanning. Ewes and lambs were separated in the morning and ewes milked by machine following i.v. oxytocin (1 i.u.) and stripped by hand until empty. Ewes returned to pasture whilst lambs were housed and bottle-fed. At afternoon milking (after a precisely measured interval of about 6 h) milk yields were recorded. From that yield and the time interval, daily milk yields were calculated. Data were analysed using a mixed linear model for repeated measures. Twin-bearing ewes produced significantly more milk than single-bearing ewes (P < 0.001). Lactogenesis differed significantly (P < 0.001) between the lambing groups. Over the whole lactation, milk yield differed significantly (P < 0.001) between different lambing groups. Milk yields were highest following June lambing (2223 {\textpm} 35 g/day), followed by November (2107 {\textpm} 24 g/d), August (1932 {\textpm} 36 g/day), January (1826 {\textpm} 31 g/day) and March (1742 {\textpm} 30 g/day). A significant lambing group by rearing rank interaction (P < 0.001) indicated that single- and twin-bearing ewes responded differently to seasonal differences; ewes with twins increased milk yield proportionately more than ewes with singles in June, November and January. KEYWORDS: milk yields; sheep; STAR system. }, issn = {1176-5283}, author = {Peterson SW and Kenyon PR and Morris ST and Lopez-Villalobos N and Morel PCH} } @conference {41836, title = {A model system to investigate the regulation of lactoferrin production by the bovine mammary gland}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {290-296}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Lactoferrin (Lf) is a high value, low concentration protein found in milk. Lf concentrations are found to increase during mastitis. This study was instigated to investigate if the effect of inducing sterile inflammation of the mammary gland, using lipopolysaccharide (LPS), a component of bacterial cell walls, would be a useful physiological model to study the production of Lf. Ten multiparous Friesian-Jersey cross-bred (FxJ) cows (approximately 200 days in milk) with no recent history of mastitis were utilised. All cows were milked on an individual quarter basis, and milk samples were collected one week prior to the treatment date to provide covariate data. Eight cows were infused via the teat canal with 10 ml saline and 10 μg LPS in 10 ml saline into 2 random quarters on each cow. The other two quarters on each cow were not treated. Two cows were untreated controls. All cows were milked twice daily with milk samples collected individually from all 4 quarters for 7 days with additional samples collected at 14 and 21 days. All milk samples were analysed for gross composition (fat, protein, lactose), somatic cell count (SCC), conductivity and Lf concentration. At the first milking after treatment, LPS treatment showed a significant effect on all milk components measured. By the 4th milking after treatment Lf concentrations were approximately 3.5 fold higher in LPS treated quarters compared with saline infused quarters, and remained elevated until 7 days after treatment. SCC remained elevated (P < 0.01) in the LPS treated quarters until day 7 also. These results show that LPS can be used to induce the production of Lf in lactating cows and therefore provides a model with which to further investigate the mechanisms that control Lf production. KEYWORDS: lactoferrin; lipopolysaccharide; endotoxin; somatic cell count; conductivity; milk composition. }, issn = {1176-5283}, author = {Turner S-A and Thomson NA} } @conference {41568, title = {Modelling dairy system efficiencies}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {203-208}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {The Dexcel Whole Farm Model (WFM) is being developed to simulate dairy systems based on the interaction of system components. The WFM was fitted against observed data from the Resource Efficient Dairying (RED) trial, Scott Farm, Hamilton (Treatment A, 2002/2003 season) and used to explore the effects of different stocking rates on measures of system efficiency, i.e. feed utilisation (FU) and feed conversion efficiency (FCE). At the same stocking rate as RED treatment A (3 cows/ha), and with the observed {\textquoteleft}bestpractice{\textquoteright} management principles in place, the WFM predicted a FU 7\% higher compared with the observed (73\% vs 66\%). Increasing stocking rate in the WFM resulted in an increase in FU, but the predicted FCE did not decrease as was expected. The model showed the importance of adhering to proven management principles to reduce feed wastage and thereby improve system efficiencies. Key words: stocking rate; simulation modelling; pasture utilisation; dairy farm. }, issn = {1176-5283}, author = {Jensen RN and Beukes PC and Clark DA and MacDonald KA} } @conference {41554, title = {Modelling the effects of zero-inductions on profitability in dairy systems}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {132-136}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Inductions are an animal welfare issue and regulations aim to achieve < 2\% inductions on a national basis by 2010. There is a need to assess the longer-term impacts of alternative reproduction management strategies on farm economics and their success in solving the problem of poor reproductive performance. Dexcel{\textquoteright}s Whole Farm Model was calibrated against observed data from Lincoln University Dairy Farm where 11\% of the herd was subjected to inductions in the 2002/03 season, but a zero-induction policy has since been adopted. Results from one-year simulations over five different climate years showed a significant decrease in farm profit ($105/ha, P < 0.05) from the benchmark farm with 11\% inductions (following {\textquoteleft}best practice{\textquoteright} guidelines) to a farm where the late-calvers were culled and replaced by bought-in early-calving heifers and where stocking rate was raised moderately (< 10\%) to compensate for the higher proportion of heifers in the herd. Multiple-year simulations reflecting carry-over effects showed that a strategy with a 10-week mating period, annual culling of 25\% of the herd including all empties and replacement with synchronized heifers mated to start calving one week before planned start of calving can match the farm profitability of the {\textquoteleft}Induction{\textquoteright} strategy if implemented consistently for 5-8 years. Key words: calving spread; modelling; synchrony; mating; replacement. }, issn = {1176-5283}, author = {Beukes PC and Thorrold BS and Wastney ME and Glassey CB and Burke CR and Van Bysterveldt AM} } @conference {41537, title = {National genetic evaluation for somatic cell score}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {59-62}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {The method for the national genetic evaluation of somatic cell score (SCS) in New Zealand is described. Evaluation was done using a multiple-trait random regression test day animal model. Trait one was the first-lactation SCS record and trait two was the records from the second and third lactations. Third-order Legendre polynomials of days in milk were fitted to the genetic and cow effects. The evaluation was done across breed. In the first national evaluation, the pedigree contained 15.9 million animals. There were 22.7 million first lactation test day records and 35.4 million second/third lactation test day records. Solutions were obtained using a preconditioned conjugate gradient solver and iteration on data. The resulting breeding values (BVs) indicate a small annual increase (0.01 to 0.03 genetic standard deviation units) in SCS. The range in sire BVs indicate the potential to select for decreased SCS. KEYWORDS: somatic cell score; genetic evaluation; test day model; dairy cows. }, issn = {1176-5283}, author = {Harris BL and Winkelman AM and Montgomerie WA} } @conference {41846, title = {New versions and uses for wool}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {336-339}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Based on a strong understanding of wool and its components, and strong support for the science behind those components and their application, Keratec Limited has created new versions and uses of wool, as keratin protein products in a range of markets, including personal care, medical devices and consumer health. The scientific approach taken by Keratec Limited, and recent developments in each of the target product areas will be discussed. }, issn = {1176-5283}, author = {Kelly RJ and Foulds BK and Sigurjonsson F and Roddick-Lanzilotta A} } @conference {41845, title = {Novel versions and uses for animal products}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {335}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {

The genesis of this contract session was a perceived need for an update on the progress being made in the well-documented objective of those involved in the processing and marketing of animal products to move at least a proportion of what was historically a commodity into more valuable market niches. The potential of entry into the apparently lucrative markets of functional foods, pharma- and nutraceuticals, human medicine, and health and wellness has spawned new areas of research and development{\textellipsis}

}, issn = {1176-5283}, author = {Nicol AM} } @conference {41825, title = {Predicting next oestrous date and drafting automatically milked cows for focused attention on oestrous detection}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {231-235}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {The autumn-calving herd at the Dexcel Automatic milking farm was used to test a system of predicting next oestrous date for individual cows and automatically drafting them for focused observation of behavioural oestrus. During the first 21 days of artificial inseminations (AI), the automatic milking system was programmed to draft cows into a holding paddock on each of three days either side of the due date for next oestrus, which was predicted from oestrous dates and milk progesterone concentrations collected prior to the planned start of mating. Cows drafted into the holding paddock were visually checked in the morning, released if not in oestrus or retained if in oestrus for AI later in the morning. The remainder of the herd was also visually checked for oestrus in the morning and afternoon. During the first 21 days of mating, 29 of the 37 cows (78\%) were inseminated, and 22 (76\%) of these were inseminated within the predicted {\textquoteleft}six-day separation window{\textquoteright}. Of these 22 cows, 15 (68\%) were detected as being in oestrus after being drafted into the holding paddock. A system for drafting cows due to be in oestrus for focused observation is achievable in practice, although improved performance will be necessary to reach the desired level of reliability. KEYWORDS: oestrous detection; automation; dairy cattle. }, issn = {1176-5283}, author = {Burke CR and Davis KL and Jago JG} } @conference {41854, title = {Preliminary examination of the New Zealand event horse production system}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {372-377}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Three day eventing is a sport that places large physical demands on the equine athlete and is a considerable export earner. However there are no published data concerning the size or scope of the New Zealand event horse production system. Quantification of the current production system is important for development of animal breeding programmes and the minimisation of wastage. Retrospective data were obtained from the Equestrian Sports New Zealand horse and rider databases for the 1994/95 to 2000/2001 competition seasons. Basic descriptive statistics were used to describe the horse population. The competitive life of horses registered for the sport of eventing was tested using survival analysis (Kaplan-Meier). Log rank test was used to test the effects of age, sex, breed, horse grade and rider level on survival. In the 1994/95 season 1612 horses were registered for eventing (5\% in advanced, 15\% intermediate and 81\% in novice grades). Mean horse age was 9.7 {\textpm} 3 years and 75\% of the horses were geldings. Thirteen breed categories were identified, most horses being either Thoroughbred (46.2\%) or unrecorded (43\%). Only 56\% of the horses registered in the 1994/95 season were still registered six years later. There was no effect of sex, breed, or rider level on survival. Advanced and novice horses had poorer cumulative survival than intermediate horses (40\%, 55\%, and 64\% respectively; log rank 12.06, P < 0.001). Not unexpectedly, survival was related to age with horses aged >10 years in the 1994/95 season having a lower cumulative survival (47\%) than horses aged < 6 years (60\%) or aged 7-10 years (63\%) (log rank 25.15, P < 0.01). It appears that novice horses leave the system because of sale or lack of talent. The greater relative loss of advanced horses may reflect either the age of the horses once they reach advanced grade, or possibly the relentless work associated with training and competition. Further prospective study is required to quantify the reasons for loss in the various age and grade categories. KEYWORDS: horse; event horse; wastage; industry structure. }, issn = {1176-5283}, author = {Rogers CW and Firth EC} } @conference {41526, title = {Presidential Address 2004: The changing face of animal science in society}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {1-3}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {It is a very interesting exercise to go back to the first few editions of our own proceedings and examine the areas of research that occupied the attentions of our members around 60 years ago. While the tools we use today are far superior to the techniques of their day, many of the questions asked have changed little over that time. Our research is still mostly related to how we can make better or more efficient use of our animal and land resources to produce a range of products to suit the markets of the day. However, what has changed significantly over that period is what society considers to be acceptable use of our animal and land resources{\textellipsis} }, issn = {1176-5283}, author = {Jopson NB} } @conference {41538, title = {The productivity of pasture-based dairy farms in New Zealand with different levels of extra feed input}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {63-67}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {The objective of this research was to study the physical and financial performance of commercial dairy farms in New Zealand that differed in the amount of extra feed used. Data from Dexcel{\textquoteright}s ProfitWatch corresponding to 626 owner-operated dairy farms between 1998/1999 and 2001/2002 were analysed. The data were classified according to each of the four dairy seasons and the extra feed used per cow. Extra feed comprised supplements imported (hay, pasture silage, maize silage, concentrates and other feeds), winter grazing and maize silage grown on the farm. The statistical analyses were done in SAS and comprised analyses of variance and regression analyses. High feed input farms (H farms, 740-940 kg extra DM /cow/year) had higher stocking rates (2.7-2.8 vs 2.4-2.5 cows/ha), lower comparative stocking rate (83-86 vs 83-92 kg live weight/t DM), and higher milksolids (MS) production per cow (293-341 vs 249-295 kg MS/cow) and per hectare (826-921 vs 616-744 kg/ha) than low feed input farms (L farms, 20 kg DM extra feed/cow/year). The use of nitrogen fertiliser was also higher in the H farms than in L farms (85-116 vs 53-67 kg N/ha/year). There were no significant differences in farm size, herd breeding worth, reproductive characteristics of the herds and estimated pasture consumed per hectare. On average, extra feed was significantly associated with extra cows (0.17 extra cows/ha for 1 t extra DM) and extra milk solids (50 g extra MS/cow for 1 kg extra DM/cow and 96 g extra MS/ha for 1 kg extra DM/ha), but the wide variability is shown by the low values for R2 (0.13 to 0.16 for the three relations above). The H farms produced higher gross farm incomes per hectare (by $0.47 to $0.49/kg extra DM offered) but had higher farm working expenses per hectare (by $0.36 to $0.37/kg extra DM offered), so that Economic Farm Surplus per hectare was not higher for these farms in any year. High management skills and control of costs are necessary for profit to be increased by the use of extra feeds. KEYWORDS: low-input; high-input; extra feed. }, issn = {1176-5283}, author = {Silva-Villacorta D and Holmes CW and Shadbolt NM and Lopez-Villalobos N and Prewer W and Glassey CB and Blackwell M} } @conference {41839, title = {Puberty in red deer hinds : (1) Onset of luteal and mating activity}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {306-311}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Pregnancy rate of yearling (15-18 months) red deer hinds may be influenced by time that puberty is attained, especially if stags are removed before all hinds have had a chance to conceive. This paper reports on two studies that investigated onset of puberty in red deer hinds. In Study 1, ovarian follicle populations and luteal activity of pubertal and adult red deer hinds were monitored for three months during their transition into the breeding season. Yearling (n = 5) and adult (n = 5) hinds were grazed in one group and weighed monthly. A fertile stag was run with them from 20 March until 11 May. Yearling hinds were significantly lighter than adults in March (85.8 vs 91.3 kg, SED = 2.1). There were no significant differences between yearling and adult hinds in mean day of first (14 April vs 8 April, SED = 3.5) or second (23 April vs 16 April, SED = 3.7) ovulations, or interval between ovulations (9 vs 8 days, SED = 0.7). First ovulation was invariably followed by a transient rise in plasma progesterone concentration and then a second ovulation preceded by oestrus. All hinds conceived to their first mating, demonstrating the ability of red deer hinds to exhibit high conception rates. In Study 2, daily observations for mating activity of yearling (n = 80) and adult (n = 80) hinds were carried out continuously from dawn until dusk for the period 25 March-27 April. Hinds were grazed on pasture in one of five single sire mating groups: Gp1, adults only (n = 40); Gp2, yearlings only (n = 40); Gp3, adults (n = 20) + yearlings (n = 20); Gp4, adults (n = 10) + yearlings (n = 10); Gp5, adults (n = 10) + yearlings (n = 10). Hinds were scanned by rectal ultrasonography to determine pregnancy status and estimate fetal age. Yearling hinds were significantly lighter than adults in March (101 vs 119 kg, SED = 1.3). The stag in Gp3 was replaced due to exhaustion and consequently, mean conception date of yearlings in that group was 16 days later than that of the yearlings in Gps 2,4 \& 5, which had a mean conception date 12 days later than that of the adults (1 May vs 15 April vs 3 April, SED = 1.1; P < 0.001). There was no significant difference between age groups in the number of non-pregnant hinds. These data indicate that yearling red deer hinds reach puberty and are mated in mid-April, about two weeks later than adult hinds. Conception failure was not a limiting factor to yearling reproductive performance; therefore, under standard farming conditions, it is unlikely that stags will be removed from the mating mob before yearling hinds have had a chance to conceive. KEYWORDS: red deer hinds; puberty; reproduction. }, issn = {1176-5283}, author = {Scott IC and Asher GW and O{\textquoteright}Neill KT and Littlejohn RP} } @conference {41840, title = {Puberty in red deer hinds : (2) Effects of introducing spiker stags in early January}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {312-315}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Calving date of yearling red deer hinds is, on average, two weeks later than that of adult hinds, further misaligning feed quality with nutritional requirements. The hypothesis that early joining of spiker stags with yearling red deer hinds would increase pregnancy rate and advance date of conception was studied. Yearling hinds (n = 309) were grazed in one group at least 500 m from any stags from the first week in November until 14 January when hinds were weighed, wapiti scored and randomly allocated to either an early stag joining (ES) or control (C) treatment. ES hinds were grazed as one group with 20 spiker stags and C hinds were kept in paddocks well removed from stags. On 2 March, all hinds were weighed again and 20 spiker stags joined with the C hinds. ES and C groups were grazed separately until being combined in mid-April. The stags were removed on 18 May, and hinds ultrasound pregnancy scanned on 1 June. There were no significant differences (P > 0.05) between ES and C treatments in mean wapiti score (1.8 vs 1.8, SED = 0.08), live weight (January: 79.8 vs 79.0 kg, SED = 0.86; March: 86.4 vs 85.8 kg, SED = 0.85), fetal age (48.5 vs 46.8 days, SED = 1.0) or percent hinds pregnant (85.7 vs 88.7 \%, SED = 3.5). The probability of hind pregnancy increased significantly with live weight within wapiti score classes and decreased with increasing wapiti score (P<0.01), such that, with mean class live weights of 75, 81, 88 and 95 kg, the expected percentage of pregnant hinds was 95, 91, 88 and 73 \% for wapiti scores of 1, 2, 3 and 4+, respectively. Fetal age increased by 0.11 (SEM 0.054) day for every 1 kg increase in January live weight (P < 0.05), but showed no significant relationship with wapiti score. These data indicate that early joining of spiker stags did not significantly improve the pregnancy rate or advance conception date of yearling red deer hinds. KEYWORDS: red deer hinds; puberty; early stag joining. }, issn = {1176-5283}, author = {Scott IC and Ward JF and O{\textquoteright}Neill KT and Littlejohn RP} } @conference {41855, title = {Re: Relation between sweating and wool yellowing in Merino and Romney sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {378}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {

In the original printed version of this paper, incorrect labelling of some of the axes occurred in two of the figures. Corrected versions are shown below. The authors regret this error.

}, issn = {1176-5283}, author = {Sumner RMW} } @conference {41533, title = {Regulating milk fat synthesis: potential on-farm applications of basic science}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {33-39}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = { This review covers results from numerous trials evaluating conjugated linoleic acid (CLA) effects on milk fat synthesis and its potential as an on-farm management tool to improve dairy cow performance. Supplemental CLA reduces milk fat synthesis in numerous animal models, and in grazing dairy cows can improve energy balance as well as increase milk and milk protein yield. Mammary lipid metabolism effects are thus far specific to trans-10, cis-12 CLA, and we demonstrated trans-10, cis-12 CLA reduces mRNA expression of enzymes required for de novo fatty acid synthesis, fatty acid uptake and intracellular transport, and triglyceride formation. The amount of CLA required to reduce milk fat synthesis in lactating cows has little or no effect on circulating basal bioenergetic metabolites and hormones or stimulated responses to homeostatic signals. We hypothesized CLA can be utilized to stimulate milk fat depression when milk synthesis and other physiological processes are limited by energy availability, as is the case in early lactation, during heat stress and occasionally in pasture based dairying. Our research focuses on identifying the mechanisms of action and potential use of CLA as an on-farm management tool to increase farm profit via increased milk production, improved reproduction and decreased metabolic disorders.}, issn = {1176-5283}, author = {Baumgard LH and Kay JK and Moore CE and Roche JR and Vanbaale MJ and Rhoads RP} } @conference {41567, title = {Relation between skin structure and wool yellowing in Merino and Romney sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {197-202}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Five adult Merino and five adult Romney ewes were skin sampled on the back, midside and belly regions of the body following a study measuring the relationship between rate of sweat secretion and wool yellowing under various controlled environmental conditions. Densities of primary follicles, secondary follicles, sweat (sudoriferous) glands and sebaceous glands, as well as dimensions of the sweat and the sebaceous glands were measured. The density of secondary follicles was negatively related to wool yellowing and there was a weaker positive relationship between the density of primary follicles and wool yellowing. Underlying these relationships were associations of measurements suggesting sebaceous gland output restricted wool yellowing while sweat gland output encouraged wool yellowing. In addition, large sweat glands were related to increased sweat secretion rate. The results of this study suggest there may be two potential avenues to minimise fleece discolouration while the wool is growing on the sheep; either increasing sebum production or reducing sweat production. KEYWORDS: Romney; Merino; wool yellowing; wool follicles; sweat glands; sweat; sebaceous glands. }, issn = {1176-5283}, author = {Sumner RMW and Craven AJ} } @conference {41566, title = {Relationship of mean fibre diameter and time of shearing with wool yellowing in Merino sheep farmed under North Island conditions}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {191-196}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Approximately 200 adult Merino ewes at each of four sites in New Zealand, near Hamilton (Whatawhata), near Rotorua, near Havelock North (Poukawa) and near Wanganui were shorn once-yearly at five different times over two years. Groups of approximately 40 ewes in each flock were shorn pre mating (March), post mating (May), pre lambing (July) with lambs-at-foot (October) or at weaning (December/January). Midside fleece samples were collected before shearing for measurement of fibre diameter. At shearing each fleece was weighed and skirted. The skirted fleece and skirtings were weighed and core bored for measurement of wool yellowness. The between flock and between shearing time ranking for increasing wool yellowness was Wanganui, Poukawa, Rotorua, Whatawhata and lambs-at-foot, pre lambing, weaning and post mating, pre mating respectively for both the unskirted and skirted fleeces. There was a significant positive relationship between mean fibre diameter and wool yellowing with no difference in the slope of the relationship between flocks or between shearing time treatments. These trends align with finer-woolled Merino sheep having more sebaceous glands, the secretion from which appeared to protect growing wool fibres from the action of components in sweat secreted in response to warm moist atmospheric conditions. The optimal shearing time to produce the whitest wool was spring. KEYWORDS: Merino; wool yellowing; fibre diameter; shearing time. }, issn = {1176-5283}, author = {Sumner RMW} } @conference {41844, title = {Relationships among metabolic hormones, luteinising hormone and anoestrus in periparturient dairy heifers fed two nutritional levels prepartum}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {329-334}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {A mathematical model that describes the dynamics of reproductive hormones was developed to estimate the duration of the postpartum anoestrus interval (PPAI) in cows. The model identified two relatively separate mechanisms: one influenced PPAI through luteinising hormone (LH) release; and it is suggested that another one controlled ovary sensitivity to LH. Examining the role played by these mechanisms in the relationships between nutrition and PPAI involved analysing the data from an experiment that measured the effects of prepartum nutrition on PPAI in which levels of insulin-like growth factor-I (IGF-I), insulin, glucose, leptin and growth hormone (GH) were recorded. Five months before calving, 30 Holstein-Friesian heifers were randomly allocated to a high (HP) or low plane (LP) of nutrition. Body condition scores at calving were 6.3 and 4.1 for the HP and LP treatments respectively. Both groups were fed ad libitum after calving. Secretion patterns of LH were measured at 2, 5 and 8 weeks after calving. PPAI differed between treatments (HP 62.0 {\textpm} 7.95 days; LP 83.1 {\textpm} 6.95 days; P < 0.05), as did the level of GH at calving (HP 5.8 {\textpm} 1.23 ng/ml; LP 10.3 {\textpm} 1.23 ng/ml; P < 0.001). The within treatment variation in PPAI was partitioned into that associated with LH frequency post calving and that orthogonal to LH pulse frequency. Within each treatment, GH was associated with the LH frequency and insulin was associated with the component orthogonal to LH frequency. These results link nutrition to the PPAI through the dynamics of insulin and GH. KEYWORDS: mathematical model; anoestrus; dairy cows; nutrition; metabolites; LH. }, issn = {1176-5283}, author = {Pleasants AB and Chagas LM and Burke CR and Smith JF and Soboleva TK and Peterson AJ} } @conference {41556, title = {Relationships between milk yield, milk composition and electrical conductivity in dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {143-147}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {The purpose of this study was to investigate the relationships between electrical conductivity (EC) and milk yield and composition in Japanese dairy cattle. In total, 4380 quarters of 106 cows were used in this study. Individual cows were herd tested in the evening with a quarter-milker fortnightly on at least 6 occasions during the lactation. Herd test records were collected from 1990 to 1998. Each quarter was sampled for milk yield, concentrations of fat, protein, lactose and solids-not-fat (SNF) and EC. Each milk quarter sample was classified into one of 9 classes of EC value and one of 10 classes of quarter difference EC value (QdEC). The QdEC for each quarter was calculated as the difference between the EC value for that quarter and the EC value of the quarter with the lowest value within the same cow, on a given herd-test day. Statistical analyses were performed using a mixed linear model for repeated measures considering the fixed effects of quarter position, lactation stage and their interaction, parity, calving season and the EC or QdEC class, and random effects of cow and quarter within cow. Previous studies have recommended criteria for healthy quarters of < 6.3 mS/cm for EC and < 0.3 mS/cm for QdEC. In the present study, quarters with values above these criteria did have significantly lower milk yields (by 15 to 20\%), but these decreases became apparent above values for EC and QdEC of 5.4 mS/cm and 0.2 mS/cm respectively, much lower than the suggested criteria. Milk yield was reduced by approximately 2\% for every 0.1 mS/cm increase in the QdEC. The higher value classes for EC, and for QdEC both showed significantly lower concentrations of fat, lactose and SNF (P < 0.05). In the present study, decreases in milk yield and concentration of fat and lactose occurred in quarters that would have been considered to be normal by the previously accepted criteria for EC and QdEC. KEYWORDS: electrical conductivity; milk yield; milk composition. }, issn = {1176-5283}, author = {Yoshida T and Lopez-Villalobos N and Holmes CW} } @conference {41831, title = {Relationships between on-farm and pre-slaughter behaviour and growth and meat quality for bulls and steers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {261-265}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Angus and Hereford-Angus cross bulls (n = 58) and steers (n = 59) were assessed for temperament 3 times during post-weaning growth and for behaviour during pre-slaughter holding in order to investigate relationships between these traits and measures of growth and meat quality including meat tenderness and meat colour. Composite on-farm temperament scores encompassed measures during weighing of stepping and unease on the scale, and speed of movement and level of agitation when released from the scale. Pre-slaughter assessments included counts of butting, pushing, fighting and mounting. Plasma levels of cortisol, glucose, lactate and fatty acids at slaughter were measured. On-farm temperament scores were significantly correlated (P < 0.0001) between the 3 times and between measures within a time. On-farm measures, however, were not related to pre-slaughter scores or to plasma cortisol or metabolite levels. Plasma cortisol levels were significantly higher for steers than bulls (43.8 vs 22.4 ng/ml; P < 0.001) as reported previously, and bulls had significantly higher pre-slaughter behaviour scores, but there were no castration effects on levels of plasma metabolites or on-farm temperament scores. Relationships between behavioural traits and measures of growth rate and meat quality based on treatment-adjusted residuals were low and non-significant. It is concluded that despite on-farm temperament scores being moderately repeatable, these measures were not associated with differences in pre-slaughter behaviour, and neither of these traits was associated with growth rate or measures of meat quality. KEYWORDS: animal behaviour; meat quality; meat pH; cortisol; growth rate; tenderness. }, issn = {1176-5283}, author = {Burnham DL and Purchas RW and Morris ST} } @conference {41837, title = {Repeatability of fatty acid composition in pm:am milk samples from cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {297-299}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {The present study was designed to estimate the repeatability of fatty acid composition in cows{\textquoteright} milk collected at a pm:am herd test. As part of a larger project, whole milk was collected during a routine herd test in March 2003 from 10 Friesian and 10 Jersey cows at Flock House, in the evening and again the following morning. Fat in the 40 samples was separated by centrifugation, fatty acids were converted to their methyl esters, and individual fatty acid percentages in each sample were assayed by gas chromatography. In general, the fatty acid composition of milk was very similar at the pm and am samplings. For the fatty acids making the largest contributions (10 to 29\% of the total) to fatty acids present in milk (C14:0, C16:0, C18:0 and C18:1 cis-9 (oleic)) and for conjugated linoleic acid and the Mono- Unsaturated/Saturated ratio, pooled within-breed correlations of compositions between pm and am milk samples were high (0.76, 0.80, 0.88, 0.76, 0.75 and 0.74, respectively; standard errors 0.06 to 0.12). The pm:am correlation, averaged over the most abundant 15 fatty acids in milk, was 0.77 {\textpm} 0.10. It is concluded that a single milk sample or a pooled pm:am sample is adequate for estimating the composition of the predominant fatty acids. KEYWORDS: milk; fatty acid; cows; repeatability. }, issn = {1176-5283}, author = {Morris CA and Hickey SM and Agnew MP} } @conference {41849, title = {Research support for new uses and improved production of deer velvet}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {345-351}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Deer velvet is a novel agricultural product and has presented the New Zealand (NZ) agricultural and food sectors with a number of opportunities. When the velvet industry emerged in the early 1970s, almost the entire product was exported to the traditional oriental medicine markets, which remain the basis of the deer velvet industry in NZ. This market did not require scientific validation of efficacy as the health promoting effects of velvet were accepted. However, as this is a mature market there is interest in growing new business, notably the Western dietary supplement market. This requires new knowledge on health benefits as potential purchasers have no initial product knowledge. We have conducted research to investigate whether or not deer velvet will help promote health. We chose to look for a verifiable benefit to athletes as the athletic market would be less likely to be price sensitive than other sectors. We also investigated the application of specific velvet extracts as topical agents to promote healing of open wounds, based on their ability to promote the growth of blood vessels (angiogenesis). This paper discusses the research that set out to demonstrate velvet efficacy and quality and describes research on nutrition and breeding designed to increase velvet quality and quantity. KEYWORDS: deer; velvet; antlers; production; quality; wound healing; dietary supplement; health benefits. }, issn = {1176-5283}, author = {Suttie JM and Haines SR and Clark DE and Archer JA and O{\textquoteright}Connor M and Broeder CE and Corson ID} } @conference {41564, title = {The role of suckling on the parasite status of very young lambs infected with Teladorsagia circumcincta}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {182-185}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {This study investigated the importance of suckling for the resistance and/or resilience of very young lambs to Teladorsagia circumcincta nematode infection. Thirty, 6-week old twin-born lambs were allocated to four treatment groups in a 2 x 2 factorial design in which groups continued to suckle (S-) or were weaned (W-), and concurrently not infected (-N) or infected (-I) with 1000 L3 larvae of T. circumcincta per day while grazing {\textquoteleft}clean{\textquoteright} pasture for six weeks, and then slaughtered. There was a significant infection by time interaction on faecal egg counts (FEC; P < 0.001). Suckling/weaning had no effect on FEC. Worm burdens were similar in suckled-infected (SI) and weaned-infected (WI) lambs (8029 + 1502 vs 12228 + 1704 worms, SEM; P > 0.05), respectively. Eggs per utero were significantly greater (29 + 6 vs 15 + 1 eggs, SEM; P < 0.05) in SI than WI lambs, while length of female worms was similar in both groups (10.2 + 0.2 vs 9.7+0.3mm, SEM; P > 0.05), respectively. The two suckled groups progressively gained more weight (P<0.001), while uninfected lambs of both groups were heavier (P < 0.05) from day 28 onwards. Weight gain averaged 122, 282, 98, and 240g day-1 for the WN, SN, WI, and SI lambs, respectively. The study has not shown any advantage of suckling while grazing for lambs{\textquoteright} resistance or resilience to larval intake within the 12-week post lambing period. KEYWORDS: Teladorsagia circumcincta; suckled lambs; resistance; resilience. }, issn = {1176-5283}, author = {Iposu SO and Greer AW and McAnulty RW and Stankiewicz M and Sykes AR} } @conference {41565, title = {Sire-line differences in lamb losses from starvation exposure}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {186-190}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = { Sire-line differences in neonatal lamb mortality due to starvation-exposure (diagnosed using basic {\textquoteleft}on farm{\textquoteright} observations) were observed in five trials (1390 lambs in 15 sire-groups). After correcting for variations in lamb birth weight and in the cold challenge experienced by each lamb using logistic regression, sire-line differences in lamb mortality due to starvation-exposure were detected in flocks where the cold challenge and the number of progeny in each sire line was sufficient (P < 0.05). Although sire-line differences in lamb mortality due to starvation-exposure were detected independent of birth weight, the analyses revealed that birth weight is still the largest influence upon lamb mortality due to cold exposure (P < 0.05). These results confirm that due to the large and contradictory role that birth weight has in influencing lamb survival, it is extremely important to record and account for it in any attempt to breed for enhanced lamb survival. The detection of sire-line differences in lamb mortality due to starvation-exposure independent of birth weight could provide a basis to select for improving lamb survival, thus raising the efficiency of lamb production.}, issn = {1176-5283}, author = {Gudex BW and Hickford JGH and Frampton CM} } @conference {41548, title = {Software for evaluating sampling strategies and error rates in the identification of mixed meat products}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {102-106}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {DNA verification of the origin of meat within traceability systems involves the comparison of DNA samples taken at a reference stage with samples taken further down the supply chain. While such verification is well established when whole cuts of meat are involved, this is not the case for mixed-meat products made from an unknown number of contributing animals. Spreadsheet based software has been developed to analyse one DNA verification scheme for determining whether a returned product did indeed originate from a particular manufacturing batch. The scheme involves the comparison of k individual DNA samples (comprising an unknown number of individuals) from the product, with a set of s DNA samples (comprising an unknown number of individuals) taken randomly before manufacture of the batch in question. The software gives the error rate for correctly matching the product to the batch, for different sampling rate combinations of the product and at the factory. Key words: DNA verification; mixed meat; traceability; sampling. }, issn = {1176-5283}, author = {Vetharaniam I and Shackell GH} } @conference {41557, title = {A study of mastitis in two small experimental dairy herds managed either organically or conventionally during one year}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {148-152}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Mastitis infection status of two small herds located at the Dairy Cattle Research Unit of Massey University was assessed. Single quarter milk samples from 45 cows under organic production (first and second year of organic certification) and 50 cows under a conventional system were taken on four occasions: mid lactation (these samples were frozen); prior to the last milking before dry-off (season 2003/2004); before the first milking after calving and 14 days post calving (season 2004/2005). Milk samples were cultured for bacterial analysis. Somatic cell counts (SCC) from monthly herd tests, and clinical mastitis cases were recorded and analyzed. The percentages of quarters with positive bacterial growth, and SCC, were generally higher in the organic herd, but differences were only significant for Staphylococcus aureus in all four sample periods, and for Streptococcus spp. 14 days post calving. The results suggest that in organic herds Staphylococcus aureus infections could become an important concern, because of constraints on the use of antibiotic treatments. Effective prevention of infections by this organism will be essential, in order to prevent high culling rates. KEYWORDS: mastitis; organic dairy; New Zealand. }, issn = {1176-5283}, author = {Silva KE and Quinn AK and Morel PCH and Holmes CW and Thatcher A and Shadbolt NM and Kelly T} } @conference {41551, title = {A survey of the control and financial impact of footrot in the New Zealand Merino industry}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {117-122}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = { A survey was sent to 869 Merino farmers in New Zealand in August 2001 seeking information about the prevalence of footrot, treatment and control measures applied, their related costs, and estimated production losses attributable to the disease. There were 304 respondents to the survey and they farm approximately 43\% of the Merino sheep in New Zealand. Footrot was reported to be present in 59\% of the respondents{\textquoteright} flocks with 6.4\% of the sheep infected by footrot at the time of surveying. Foot bathing, culling of affected sheep and breeding for footrot resistance in flocks were the preferred control measures. Footrot treatment was calculated to cost $1.67 per Merino sheep per year with an additional $1.77 per sheep attributed to losses in animal production. Assuming the respondents are representative of the New Zealand Merino industry, the total cost of footrot to this industry was estimated to be in excess of $11 million annually.}, issn = {1176-5283}, author = {Hickford JGH and Davies S and Zhou H and Gudex BW} } @conference {41541, title = {Traceability around the world}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {75-79}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {With the business case for a national animal identification system due in July 2005, it is appropriate to take stock and to see where New Zealand (NZ) and other countries are at with animal and full supply chain traceability. The objective should be to learn and contribute to the outcome. Full supply chain traceability is on the horizon, NZ needs to be proactive and valuable lessons are available particularly from the United Kingdom (UK) and Canadian experiences. The preferred position seems to be one where government plays a leading role without burdening the industry with yet another set of legislative requirements. For this to work effectively, the industry has to commit to traceability, to go beyond ordinary compliance type applications and to use it as a differentiator in the market place. Traceability is not going to go away, and as the requirements will continue to increase around the world, the best option is to embrace it.}, issn = {1176-5283}, author = {Nortje GL} } @conference {41540, title = {Traceability contract session: Introduction}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {74}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {

Food safety issues, especially those associated with animal disease (e.g. BSE in cattle), human health (e.g. salmonellosis), genetic modification and animal welfare are driving consumer pressure for traceability of animal-derived foodstuffs. Several of our trading partners already have in place, or have signalled, expected compliance dates for meat traceability requirements.
This contract session addresses some of the background as to why, and when, New Zealand (NZ) can expect to be required to have traceability procedures in place to ensure continued access to the world{\textquoteleft}s meat and animal derived foodstuffs market. The following 10 papers will also describe examples of what is currently in place or projected to become available for tracing animals on the farm, during transport and through meat processing plants both in NZ and overseas. The mix of speakers has been chosen to encompass legislative, industry and scientific aspects of traceability of meat and meat products.

}, issn = {1176-5283}, author = {Shackell GH} } @conference {41545, title = {Traceability databases in the New Zealand sheep industry}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {91-92}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Sheep traceability will become a necessity in New Zealand to cover consumer, biosecurity and international trade requirements. The requirement to track individual sheep from lamb processors to the farm of birth is a major logistical challenge but is considerably easier than in some of New Zealand{\textquoteright}s trading partners. Definition of the requirements of a traceability system and implementation into an effective model are still under debate. A major requirement is the design and implementation of a central database to cater for present and future needs. A traceability system could be developed using databases and technology already used in the sheep industry. }, issn = {1176-5283}, author = {Cruickshank CJ} } @conference {41547, title = {Traceability systems in the meat industry}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {97-101}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {New Zealand is reliant upon maintaining export markets for the sale of a significant proportion of its meat and dairy production. Any loss of key overseas markets has significant implications for the national economy. Therefore, we are obliged to meet or stay ahead of market drivers. Increasingly, one of those drivers is product traceability for reasons of consumer confidence. While traceability systems have a relatively short history, they have traditionally been paper and/or electronic based. They are generally managed by parties with a vested interest, and their integrity is difficult to monitor. Animal products have a unique identifier, DNA, that is tamper proof. There are a number of DNA-based traceability systems around the world that are being used in the meat industry. As well as direct tracing of a meat sample back to the animal, and ultimately to the property the animal was raised on, DNA technologies are also being used on-farm for testing meat quality traits and determining the animal{\textquoteright}s pedigree. This paper describes some of the traceability options that are in use within the environment in which New Zealand is competing for trade. KEYWORDS: traceability; meat; DNA. }, issn = {1176-5283}, author = {Shackell GH} } @conference {41542, title = {An update on beef traceability regulations in Japan}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {80-84}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {An updated beef traceability system has been in operation in Japan since December 2004. This system enables consumers to check the origin of beef products, not only for table meat, but also for restaurant cuisine. The system is dependent on producers, abattoirs, meat wholesalers and meat retailers recording and managing information on each cattle beast using a ten-digit individual identification number. It would not be an exaggeration to say that the essence of the Japanese beef traceability system would not be possible without this individual identification number. Fukaya Wagyu adopted an extended traceability system by presenting detailed information which is missing in the national system. This detailed information enables a {\textquoteleft}face to face{\textquoteright} relationship to be established between the farmer and consumer. This relationship is an effort to promote the supermarket{\textquoteright}s own brand to the customer. KEYWORDS: traceability system; beef; Japan. }, issn = {1176-5283}, author = {Ozawa T and Lopez-Villalobos N and Blair HT} } @conference {41531, title = {Validation of the double ?-alkane technique to estimate the dry matter intake of red deer fed fresh ryegrass-based pasture or plantain}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {23-28}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = { The accuracy of the double η-alkane technique to estimate dry matter intake (DMI) of red deer (Cervus elaphus) fed fresh cut perennial ryegrass-based pasture (Lolium perenne cv Nui) and narrow-leaved plantain (Plantago lanceolata cv Ceres Tonic) was determined in a cross-over experiment involving five adult castrated stags housed in metabolism cages. A strong positive linear relationship between actual and estimated DMI was obtained for pasture when using both C31 and C33 (C31 R2 = 0.94; P < 0.01; C33 R2 = 0.92; P < 0.01) and plantain for C31 (R2 = 0.80; P < 0.04), but not for C33 (R2 = 0.49; P < 0.19). However, the predicted DMI of deer using the η-alkane technique was underestimated up to 27.6\% for deer fed ryegrass-based pasture and overestimated up to 17.2\% for deer fed plantain when compared with actual DMI. The discrepancies between actual and predicted DMI could have been partly due to a difference of 26\% between faecal recovery rates of odd and even-chain alkanes with pasture feeding and 12\% with plantain feeding. This suggests that the η-alkane technique may not be appropriate for estimating DMI of ruminants grazing New Zealand fresh forages, especially when comparisons between forage species are required.}, issn = {1176-5283}, author = {Swainson NM and Hoskin SO and Clark H and Krause M} } @conference {41550, title = {What is driving the call for traceability ; where does the consumer sit?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {113-116}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Traceability has increased in importance for market access over the last couple of decades. This has been driven by the BSE and other food scares. This paper reviews the history of traceability, including changing consumer preferences, and the change in legislation which has also been an important factor behind this demand. The paper then reviews various studies that have assessed consumer preferences and their willingness to pay for traceability and/or Country of Origin Labelling (COOL). In general, consumers are willing to pay extra for traceability. The reasons behind this appear to be primarily driven by demands for food safety, especially in relation to certain food scares such as to avoid BSE beef. New Zealand is in an excellent position regarding its ability to comply with these requirements. }, issn = {1176-5283}, author = {Saunders CM} } @conference {41841, title = {Zearalenone challenge in sheep : urine sampling to measure response}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {316-319}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Zearalenone is a fungal toxin produced by Fusarium species commonly found on autumn pastures in New Zealand. It may interfere with reproductive functions in sheep. In a search for a genetic measure of susceptibility, ewe and ram lambs were dosed orally with a suspension of zearalenone at a series of rates, at 8 and 11 months of age. Urine samples were taken at intervals from 2 to 50 hours later. The concentration of urinary zearalenone and its metabolites (Zen) was assayed using an ELISA. Adjustment for urinary volume was made by measuring the urinary concentration of creatinine (Cr), and results were expressed as Zen/Cr ratio (loge-transformed). In a separate experiment, breeding ewes were dosed with zearalenone at a single rate, and Zen/Cr response was measured. The following effects were evaluated in lambs: a) sex difference (ewe versus ram lambs), b) responses to three dose rates, c) time-series response data. The heritability of Zen/Cr was determined in lambs and breeding ewes; results were analysed after standardising for each treatment and sampling group. Urinary Zen/Cr, 6 h after dosing, differed between ewe and ram lambs by a factor of 1.75 (ewe lambs higher; P < 0.01). Zen/Cr values for three dose rates (3, 6 and 9 mg zearalenone per lamb), averaged over three sampling time points after dosing, were 23.5, 43.2 and 59.3, respectively (P < 0.0001). Zen/Cr values for three sampling time points (2, 4 and 6 h after dosing), averaged over three dose rates, were 58.0, 35.8 and 29.0, respectively (P < 0.0001). By 50 h after dosing, the Zen/Cr average had fallen to 4\% of its 2-h value. The interaction between dose rate and time of urinary sampling was not significant for log Zen/Cr. A preliminary estimate of the heritability for standardised Zen/Cr was 0.32 {\textpm} 0.10 (P < 0.01). The dosing regime reported here could be used for a test of animal response to zearalenone in ram breeders{\textquoteright} flocks. KEYWORDS: sheep; zearalenone; dose response; urine; heritability. }, issn = {1176-5283}, author = {Morris CA and Amyes NC and Sprosen JM and Hawkes AD and Finch SC and Miles CO} } @conference {41842, title = {Zearalenone challenge in sheep : variation in ovulation rate}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {320-323}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Zearalenone is a fungal toxin produced by Fusarium species commonly found on autumn pastures in New Zealand, and it may interfere with reproductive functions in sheep. We have measured both ovulation rate after challenge with zearalenone, and also a metabolic indicator, Zen/Cr (the concentration of zearalenone and its breakdown products (Zen) in urine, after adjustment for urinary volume using creatinine concentration (Cr)). A small self-replacing flock of Coopworth ewes was used for the study. This paper reports a preliminary assessment of whether Zen/Cr might be an equivalent but cheaper method than laparoscopic ovulation rate for measuring an animal{\textquoteleft}s resistance to zearalenone. Ovulation rates were determined in ewes in autumn before dosing (Lap1; Years 1 and 2), and after dosing (Lap2; Years 1 to 4) with 10 mg zearalenone per animal per day for 6 days. The average reduction in ovulation rate following dosing (Years 1 and 2: Lap1 minus Lap2) was 0.60 ovulations or 31\% of the mean. Lap2 was used for the present correlation analyses. The heritability of Lap2 was estimated (0.11 {\textpm} 0.09), and breeding values (BVs) for Lap2 were determined. Subsequent to the laparoscopy, the ewes were mated at pasture, and the resulting natural litter sizes were monitored in relation to BVs for ovulation rate after challenge. Urine samples were taken during and after dosing in Years 3 and 4, to measure Zen/Cr, and a heritability for Zen/Cr (0.32 {\textpm} 0.10) was estimated from these and other Zen/Cr data. Preliminary analyses of BVs for Lap2 and Zen/Cr revealed a negative correlation between them (r = - 0.55). Ewes with higher BVs for ovulation rate also had higher mean litter sizes following natural ovulation. In conclusion, zearalenone affects ovulation rate at moderate challenge levels, and this ovulation rate may be negatively related to the concentration of measurable urinary zearalenone metabolites. KEYWORDS: sheep; zearalenone; dose rate; ovulation; heritability. }, issn = {1176-5283}, author = {Morris CA and Amyes NC and Smith JF and Sprosen JM and Towers NR} } @conference {41483, title = {Advances in maize silage genetics and crop management and the impact on the NZ dairy industry}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {105-109}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Significant lifts in profitability have been achieved by New Zealand dairy farmers through the inclusion of increasing amounts of maize silage into a pasture based system. Most of this maize is grown off the dairy unit on farmer owned or leased runoff blocks or by contract growers. While there is still significant scope to improve dairy farm productivity by increasing maize silage input levels, there is considerable opportunity to also improve dairy farm productivity by reducing feed costs through improving maize silage yields, increasing milk output by lifting maize silage nutritional quality and improving agronomic stability of maize silage offering higher yields over a wider environmental range. Traditional plant breeding, genetic engineering and advances in agronomic management all have the potential to impact production potential and profitability of maize silage in New Zealand dairy farm systems. }, issn = {1176-5283}, author = {Densley RJ and Williams ID and Miller DB and Densley DW and Sapienza DA} } @conference {41466, title = {Anthropometric, metabolic and endocrine evaluation of children born following assisted conception and methylation analysis of imprinted genes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {34-35}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Numerous studies with New Zealand beef cattle have been carried out to determine responses of live weights or reproductive/survival traits to changes in the level of nutrition, at various stages during the annual production cycle. Various studies have also been carried out to describe how much of the variation for these traits of the cow or calf is genetic. This brief summary explores the possibility that some of these cattle data could be re-evaluated because of their possible relevance and analogies to current medical questions of interest. }, issn = {1176-5283}, author = {Miles HL and Peek J and Hofman P and Harris M and Billett N and Graham F and Birdsall M and Fisher R and Cutfield W} } @conference {41519, title = {Are elevated maternal thyroid hormone concentrations after-mid-pregnancy shearing responsible for changes in lamb fleece characteristics?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {272-276}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {This study was designed to test the hypothesis that elevated maternal thyroid hormone concentrations in mid- pregnancy are responsible for the observed differences in lamb follicle characteristics as a result of mid-pregnancy shearing. The study involved 51 twin-born lambs in a 2 x 2 factorial design involving dams that were either shorn or unshorn in mid pregnancy and had either normal or elevated thyroid hormone levels. All ewe groups were thyroidectomised except for unshorn-normal ewes which were sham-operated. The thyroxine implant and injection regimes used to manipulate maternal thyroid hormone levels in mid-pregnancy were successful in mimicking the levels previously reported in mid-pregnancy shorn ewes. Lambs born to shorn dams had significantly (P<0.05) higher coefficients of variation of mean fibre diameter. Dam shearing treatment had no effect on any other follicle or wool characteristic. Lambs born to ewes with elevated thyroid levels in mid-pregnancy had a significantly (P<0.05) higher numbers of secondary fibres, and tended to have more primary fibres (P=0.08) and whiter wool (P=0.06). The absence of any dam shearing-treatment effect on secondary and primary fibre numbers, fibre diameter and length, suggests that the changes observed in follicles and wool characteristics of lambs born to mid-pregnancy shorn dams are primarily due to elevations in maternal thyroid hormone levels in mid-pregnancy. More work is required to confirm this hypothesis. }, issn = {1176-5283}, author = {Kenyon PR and Sherlock RG and Morris ST} } @conference {41465, title = {Can mating ewes on condensed tannin-containing forages be used to reduce lamb mortality between birth and weaning?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {30-33}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Five grazing experiments are described where ewes were fed forages which are likely to increase the absorption of essential amino acids (EAA) for periods of 63-70 days, immediately before and during mating, relative to control ewes mated on grass based pastures. The legume Lotus corniculatus (Birdsfoot trefoil CV Grassland Goldie) was fed in two experiments and supplements of willow or poplar forage trees were given to ewes mated on low quality drought pasture in three experiments. Both L. corniculatus and the forage trees contained condensed tannins (CT) and in addition the crude protein content of the forage trees (166 g/kg DM) was much higher than that of drought pasture (122 g/kg DM). Mating on L. corniculatus and supplementing with forage trees consistently increased lambing percentage. Lamb mortality between birth and weaning was significantly reduced (P<0.05) by mating on L. corniculatus in one experiment and by feeding forage trees during mating in one experiment. Similar trends of smaller magnitude were evident in the other experiments and did not attain statistical significance. Hypotheses of how feeding these forages during mating may have reduced post-natal lamb mortality are advanced and methods of testing the hypotheses are suggested. }, issn = {1176-5283}, author = {Barry TN and Parkinson TJ and Ramirez-Restrepo CA and McWilliam EL and Lopez-Villalobos N} } @conference {41475, title = {Can we use change in core body temperature to evaluate stress in sheep?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {72-76}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Physical and psychological stressors are known to cause a transient increase in the core body temperature of mammals. We hypothesized that rise in core body temperature could be used to indicate the intensity of stress experienced by sheep. Based on established indices of stress, we ranked five treatments from very low to severe stress as follows: Holding with flock mates, Human presence, Visual isolation, Capture and inversion, and Simulated shearing. Change in core body temperature was measured remotely using thermal sensors placed in the ear canal of the sheep. Maximum change in core body temperature (p=0.08) and the area under the core temperature change curve (p=0.09) allowed differentiation of the least and most stressful treatments: Holding with flock mates and Simulated shearing. The intermediate treatments could not be differentiated using change in ear canal temperature. Therefore, given the levels of statistical significance, our hypothesis that stressors of different intensities could be discriminated by changes in ear canal temperature was only partially supported. Reasons for the inability to discriminate between all treatments include a lack of sensitivity of change in ear canal temperature as an index of stress, high individual variability in responses to stress, and thermal sensor malfunction. }, issn = {1176-5283}, author = {Beausoleil NJ and Stafford KJ and Mellor DJ} } @conference {41507, title = {Comparison of two-stage selection breeding programmes for terminal sire sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {212-216}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Two-stage selection is a technique used in animal breeding to make the use of expensive measurements economically viable in a breeding programme. Selection candidates are first screened using inexpensive, but imperfect, predictors of their genetic merit. A selected subset are then evaluated using more accurate, but expensive, measurements and the final selection is made. This study compared the assessment of carcass composition traits using either computed tomography (CT) scanning or progeny testing (with 10 or 20 progeny per sire; PT10 and PT20, respectively) in the second stage of two stage selection systems using quantitative genetic theory. Stage 1 selection was assumed to be based on live weight and ultrasonic predictions of carcass merit. For a genetic correlation of 0.7 between ultrasonic and CT/PT measures, the economic return peaked for progeny test at $2.70 and $2.38 per commercial ewe when 10 and 5\% of the male selection candidates were evaluated in PT10 and PT20, respectively. CT had a greater return at $3.52 per commercial ewe when 20\% of the male selection candidates were evaluated using CT. The results show that given the moderate heritability of carcass composition traits, the reduction in generation interval and the lower cost of evaluation of CT outweighs the increased accuracy of selection and higher mating ratios associated with progeny testing. }, issn = {1176-5283}, author = {Jopson NB and Amer PR and McEwan JC} } @conference {41496, title = {Condensed tannins in birdsfoot trefoil (Lotus corniculatus) reduce methane emissions from dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {160-164}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Ruminant methane production contributes 34\% of New Zealand greenhouse gases, but emissions are affected by feed type. A trial conducted at Dexcel measured methane production by 32 Friesian dairy cows grazing either good quality perennial ryegrass pasture or birdsfoot trefoil (lotus, Lotus corniculatus), a legume with high nutritive value that contains condensed tannins (CT; 2.62 g CT/100 g DM). Half the cows on each diet were drenched with polyethylene glycol (PEG) to inactivate the CT and allow the effect of CT on methane production to be determined. Total methane production, measured using the SF6 tracer technique, was similar for the lotus and ryegrass cows (343.2 vs 360.6 g CH4/cow/d; ns), however, methane production per unit DMI was lower from cows fed lotus (19.9 vs. 24.2 g CH4/kg DM, P<0.001). The CT in lotus reduced methane production by 13\% relative to lotus when the CT had been inactivated by PEG, and was responsible for 66\% of the difference between lotus and ryegrass. Cows fed lotus produced 32\% less methane/kg milksolids compared to good quality ryegrass. The feasibility of feeding lotus as a methane mitigation option should now be assessed at a farm systems level to investigate effects on other greenhouse gases, productivity and profitability. }, issn = {1176-5283}, author = {Woodward SL and Waghorn GC and Laboyrie PG} } @conference {41476, title = {Dairy technology contract session}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {77}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

Currently, several very significant research projects are being undertaken in New Zealand that will impact the pastoral industry, and the dairy industry in particular, during the next ten years. This session highlights some of the technologies in the R\&D pipeline, examines the impact these technologies will have on the industry, and explores what this means for the way scientists conduct animal production research.
Professor John McRae, Deputy Director of Research at the Rowett Institute, UK, is the Landcorp Lecturer who opens the session by giving a world view of some of the new technologies and opportunities for pastoral industries. Undoubtedly one of the largest advances expected in the next ten years will be in animal genetics. John McEwan (AgResearch) describes the bovine genome project and what the project means for New Zealand, Richard Spelman (Livestock Improvement Corporation) provides an update on the search for bovine QTL, and Bill Montgomery (LIC) describes the future genetic progress of dairy cattle and the implications for the industry.
Exciting progress is also being made in forage production. Dr Kieran Elborough (ViaLactia Biosciences) relates the advances being made in forage production and the implications for pastoral industries, and Ian Williams (Genetic Technologies, Pioneer) presents recent advances in maize hybrid technology. The session concludes with Stuart Gordon (LIC) describing customer focused technology, and John Caradus (Dexcel) presenting how these technologies may be integrated into future farm systems.

}, issn = {1176-5283}, author = {Anonymous} } @conference {41521, title = {Dark fibre content of some New Zealand export wool consignments}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {282-285}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Levels of dark fibre contamination were determined on 49 core samples of scoured wool, representing 30 export consignments of crossbred wool received from three exporting companies. The concentrations of dark fibres ranged from 0 to over 3300/kg. Only four consignments contained less than 100 dark fibres/kg, twelve contained less than 500/kg, while four contained more than 2000/kg. The two highest levels of contamination (>2300/kg) were found in consignments containing lambs wool, although other consignments with lambs wool contained relatively low levels (<500/kg). Some fleece blends also contained relatively high levels of contamination (>1000/kg). All consignments containing down fleece wool were contaminated with dark fibres to levels which were highly correlated with the proportions of down fleece wool. Overall, 53\% (range 7-100\%) of the dark fibres found were melanin pigmented, 14 \% (range 4-33\%) were urine stained and 25\% (range 5-63\%) were of foreign origin. The results indicate that there is a considerable degree of dark fibre contamination in some export consignments of New Zealand crossbred wool. The one single factor consistently associated with increased levels of contamination was the presence of down fleece wool in the blend. The presence of lambs wool was associated with high levels of contamination in some consignments, but not in others. This suggests that only some lines of lambs wool contain high levels of dark fibre contamination. }, issn = {1176-5283}, author = {Reid TC and Urquhart RA} } @conference {41459, title = {Decreased gene expression of integrins in epithelial cells during mammary engorgement}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {11-13}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {In ruminants, the molecular mechanisms regulating mammary involution and apoptosis (programmed cell death) are not well characterised, but extensive research in rodents has established that many cell types, including mammary epithelial cells, require anchorage to the extracellular matrix for survival. This anchorage is mediated via the integrins, a family of transmembrane glycoproteins that bridge intra- and extracellular compartments enabling direct communication between adaptor molecules in the cytoplasm and specific receptor motifs on the ECM proteins (Clark \& Brugge, 1995; Giancotti \& Ruoslahti, 1999; Hynes, 1992). Integrins form heterodimers between α and β subunits to produce more than 20 different receptors, and many subtypes have been identified in mammary glands (Clark \& Brugge, 1995). We have shown previously that one such integrin, β1, is reduced rapidly as a result of induced weaning in rodents, and these changes are followed by apoptosis (McMahon et al., 2004). The aim of this study was to investigate the molecular mechanisms that may regulate mammary involution in the bovine by examining cell-matrix interactions that may be involved in survival of mammary epithelial cells, ultimately to improve lactational persistency and tolerance of extended milking intervals ... }, issn = {1176-5283}, author = {Singh K and Dobson J and Stelwagen K and Prosser CG and Farr VC and Molenaar A and Davis SR} } @conference {41500, title = {Economical analysis of year round lamb production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {179-182}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {The traditional lamb production system in New Zealand is driven largely by the seasonal pattern of pasture growth and ewes lambing once a year. An alternative is the implementation of year-round lamb production systems such as the STAR system, where ewes lamb five times over a three-year period, thus providing a continuous supply of lambs. A modelling exercise was undertaken to assess the economic viability of the STAR system. The model simulates pasture growth and flock energy requirement on a daily basis over a three year period for both the traditional system and the STAR system and calculates gross margins. The model was run for a 100ha block using average Manawatu pasture growth rates. The two systems were set to consume 11000 kg DM/ha of pasture per year. The model indicates that, at the same lambing percentage (160\%) the STAR system earned an extra 26\% of income compared with the traditional system. Even at a lower lambing percentage (148 versus 160) the system can match a seasonal lamb production system. With a 10 \% premium for out of season lambs the STAR system generates an extra 56\% in profit. }, issn = {1176-5283}, author = {Morel PCH and Kenyon PR and Morris ST} } @conference {41492, title = {Effect of dose of Streptococcus uberis infused into the mammary gland of lactating cows on clinical signs, bacterial count, somatic cell count and milk production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {143-146}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {This study was to evaluate changes in cow productivity and milk value from feeding a rumen-protected form of CLA to pasture-fed dairy cows in early lactation. 30 New Zealand Friesian dairy cows were randomly assigned at calving to either 0g (control) or 120g/d of a commercial rumen protected feed containing CLA from 4 days post-calving for 16 weeks. Milk yield and composition data was collected weekly. A simulation model was used to calculate yield of dairy products based on accumulated yields of milk and its components per cow during the experimental period. Feeding CLA reduced (P<0.001) fat concentration (3.1\% vs 4.2\%) and increased (P<0.05) milk yield (2688 kg vs 2423 kg), and protein yield (89.9 kg vs 81.2 kg). The effect of CLA on milk fat concentration was reflected in the yield of dairy products and milk value. Milk from cows fed CLA had less (P<0.01) excess of fat sold as butter (48.4 vs 69.4 kg butter). The value of milk ($/kg MS) was higher (P<0.001) from cows fed CLA than from control cows at 2002/03 prices ($3.87 vs $3.66) and when butter price was low ($3.56 vs $3.24).}, issn = {1176-5283}, author = {McDougall S and Parker K and Swift S and Harcourt S and Sutherland G} } @conference {41503, title = {Effect of ergot alkaloids on liveweight gain and urine lysergol level in ewe hoggets and heifers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {192-196}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Ingestion of ergot alkaloids can reduce live-weight gain (LWG) in sheep and cattle. The objective of this experiment was to determine if the enzyme-linked immunosorbent assay (ELISA) for urinary lysergol level provided an accurate measure of ergot alkaloid dietary intake. Forty hoggets and 60 heifers were fed ryegrass seed containing ergovaline (EV) (0.0 to 75.0 {\textmu}g EV/kg LW hogget; 0.0 to 35.0 {\textmu}g EV/kg LW heifer) daily. The feeding trial was repeated after 30 days for the hoggets. Urine lysergol:creatinine ratio increased linearly for hoggets from 1.91 to 5.80 (P<0.001) and LWG was linearly suppressed from 110 to 60 g/d (P<0.01) and 30 days later, from 35 to -130 g/d (P<0.05) for intakes of 0.0 to 75.0 {\textmu}g EV/kg LW. Heifer urine lysergol:creatinine ratio increased linearly from 1.60 to 5.21 and LWG declined from 1.0 to 0.85 kg/d for intakes of 0.0 to 35.0 {\textmu}g EV/kg LW (P<0.05). Urinary lysergol:creatinine ratio increased by 0.056 {\textpm} 0.007 (P<0.001, r2 = 0.67) in hoggets and by 0.082 {\textpm} 0.006 (P<0.001, r2 = 0.77) in heifers, for every 1 {\textmu}g EV/kg LW consumed. These studies demonstrated a strong relationship between ergot alkaloid dietary intake and urine lysergol:creatinine ratio. }, issn = {1176-5283}, author = {Layton DL and Fletcher LR and Litherland AJ and Scannell MG and Sprosen J and Hoogendoorn CJ and Lambert MG} } @conference {41509, title = {The effect of ewe and lamb post-parturient behaviour on lamb survival to weaning: A comparative study of Finns and Texels}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {223-226}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Post parturient behaviours of twinning Finn and Texel ewes and their lambs were monitored under commercial conditions and a relationship sought between this and lamb survival to weaning. Texel lamb survival to weaning was greatest when Texel ewes quickly made contact with their lamb following birth (within 2 minutes) and for lambs that located their dam{\textquoteright}s udder within 30 minutes from birth. Finn lamb survival to weaning was improved when Finn lambs were more vocal after birth, when Finn ewes had higher MBS and when Finn ewes spent a greater proportion of time grooming their lambs. Variation in perinatal behaviour within and across breeds was large and therefore potential exists for improving the ability of the ewe and lamb to bond successfully at parturition by selecting for some of the behaviours identified in this study that encourage lamb survival to weaning. }, issn = {1176-5283}, author = {Everett-Hincks JM and Stafford KJ and Blair HT and Lopez-Villalobos N} } @conference {41502, title = {The effect of ewe nutrition on maternal behaviour score and litter survival}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {188-191}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Mothering ability was investigated in two breeds of sheep with twin and triplet litters in 2000. The study was carried out on a commercial sheep farm with high reproductive rates gained through intensive selection in its Coopworth flock and the introduction of East Friesian genes by crossbreeding. East Friesian Coopworth (EFCoop) ewes maintained body condition between pregnancy scanning and lambing whereas Coopworth ewes lost body condition (-0.35 CS). Plasma β-hydroxybutyrate (β -OHB) was significantly higher in Coopworth ewes prior to lambing. Coopworth and EFCoop ewes with triplet litters had elevated levels of plasma {\^a}- hydroxybutyrate concentration compared to ewes with twins (0.70 {\textpm} 0.03 vs 0.49 {\textpm} 002, P<0.0001). Coopworth ewes had higher triplet litter survival rates to tagging (0.86 {\textpm} 0.03) compared with EFCoop ewes (0.68 {\textpm} 0.05) (P<0.001). The maternal behaviour score (MBS) of ewes was determined within 24 hours of birth on the basis of their response to the shepherd tagging their lambs on a 5-point scale from 1 (ewe leaves litter and does not return) to 5 (ewe remains within 1m of her litter). The maternal behaviour score (MBS) was higher in Coopworth ewes (3.6 {\textpm} 0.04) than the EFCoop ewes (3.4 {\textpm} 0.07) and increased with litter size but remained constant for EFCoop ewes regardless of litter size. The results of this study suggest that ewes that maintain condition in late pregnancy provide a more suitable maternal environment to support their litters. This is increasingly important for triplet litters. This study shows that a ewe that has slightly higher plasma β-hydroxybutyrate levels, is not as receptive to the demands of her litter and is sensitive to human interference as indicated by lower MBS. }, issn = {1176-5283}, author = {Everett-Hincks JM and Blair HT and Stafford KJ and Lopez-Villalobos N} } @conference {41497, title = {The effect of grain supplementation on the faecal pH of horses maintained on pasture}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {165-170}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {The aim of this study was to investigate the effect of grain supplementation on the faecal pH of horses maintained at pasture. Data were obtained from twelve mixed age horses kept at pasture, six controls 530 {\textpm}9.4 kg and six carbohydrate supplemented 513 {\textpm}10.2 kg. The supplemented horses were each feed up to 6.15kg of crushed oats in two feeds (am and pm) per day over a 38 day period. The supplementation was divided into seven treatment periods; a four day period with no grain (block 1), six days with the addition of grain to the diet at a rate of +0.5kg per day (block 2), six days with 3.4kg per day (block 3), four days with the addition of 0.5kg oats per day (block 4), six days fed 6.16kg per day (block 5), six days decreasing grain fed (block 6) followed by a five day observation period with no grain fed (block 7). Faecal material was collected daily for analysis immediately after defecation during the am feeding time. Throughout the supplementation trial there were no significant differences between the supplemented and control groups. There was a significant effect of period on faecal pH (P<0.05). There was no interaction of treatment and period. There was a trend for faecal pH to decrease during the trial. Block 7 was significantly different to all other blocks. Block 5 was significantly different to Block 1 (P<0.01). Within the model horse was a significant effect (P<0.05). There was a strong correlation between the control and treatment groups for faecal pH throughout the trial (r2=0.86). There was a trend for increased rainfall in the 2nd half of the supplementation trial which was associated with increasing soil temperature (P<0.01). The lack of significant change in faecal pH with increased grain supplementation indicates that for pasture kept horses factors such as pasture intake and greater activity may have a role in buffering the negative effects of a high grain diet. }, issn = {1176-5283}, author = {Rogers CW and Eastwood B and Gee EK and Firth EC} } @conference {41467, title = {The effect of pre-calving and post-calving nutritional regimes on calf birth weight and pre-weaning growth}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {36-38}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Numerous studies with New Zealand beef cattle have been carried out to determine responses of live weights or reproductive/survival traits to changes in the level of nutrition, at various stages during the annual production cycle. Various studies have also been carried out to describe how much of the variation for these traits of the cow or calf is genetic. This brief summary explores the possibility that some of these cattle data could be re-evaluated because of their possible relevance and analogies to current medical questions of interest. }, issn = {1176-5283}, author = {Morris CA and Smeaton DC and Pleasants AB} } @conference {41510, title = {Effect of precalving feeding level on the milk production of grazing dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {227-231}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Fifty-two multiparous dairy cows were allocated to four treatments with an apparent daily intake of 5.8, 8.9, 10.0 or 11.2 kg dry matter (DM)/cow/day of pasture for 27{\textpm}9.6 days precalving. This equated to 1.3, 2.0. 2.3 and 2.6\% of liveweight (not including the conceptus weight; LW). Following calving, all cows were fed generously on pasture. Daily milk yields were recorded postcalving and fat, protein and lactose concentrations determined on 2 days each week for 5 weeks. Blood was sampled 17 days precalving, on the day of calving and on days 1, 2, 3, 4, 7, 14, 28 and 35 postcalving. Precalving plasma concentrations of insulin-like growth factor-1 (IGF-1) increased (P<0.05) quadratically with increasing pasture intake. Concentrations of growth hormone declined (P<0.05) linearly and concentrations of non- esterified fatty acids declined (P<0.001) quadratically with increasing DM intake. Plasma concentrations of these metabolites postcalving showed no effect of precalving feeding. Level of feeding precalving did not affect milk yield or the yield of fat, protein or lactose in milk, but postcalving DM intake was negatively (P<0.1) related to precalving DMI. These results indicate that 0.93 MJ metabolisable energy/kg LW0.75 was required in the final three weeks of gestation to maintain cow energy balance. }, issn = {1176-5283}, author = {Roche JR and Kay JK and Kolver ES and Aspin PW and Lee J and Sugar B and Napper AR} } @conference {41498, title = {The effect of sward height during pregnancy on wool grown by ewes rearing twins or triplets}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {171-174}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Previous work estimating the impact of rearing lambs on wool growth and processing characteristics has been done primarily with single and twin-bearing ewes. The effect of bearing/rearing triplets on wool growth has been largely extrapolated from these data. The aim of this study was to compare the wool growth and quality of twin- and triplet- bearing/rearing ewes offered different sward height allowances. After pregnancy scanning, 94 Romney ewes (including 68 twin- and 26 triplet-bearing ewes) with 6 weeks wool growth, were randomly allocated to four different sward heights (2, 4, 6 and 8 cm). Within the first 24 hours of parturition ewes were transferred to one of two sward heights (4 and 8 cm). Ewes were shorn 87 days after parturition, the fleece was weighed and a sample was taken from the midside for measurement of fleece characteristics. There were no interactions between nutritional treatment and litter size for any wool measurements. Fleeces from twin-bearing/rearing ewes tended to be heavier (P<0.1 ; 2.0 kg vs 1.9 kg) than those from triplet-bearing/rearing ewes. There was no effect of litter size on any other wool characteristic. Ewes offered 2 cm during the last half of pregnancy had lighter (1.6 vs 2.2 kg, P<0.05) and finer (39.0 vs 41.8 {\textmu}m, P<0.05) fleeces than those offered 4 cm but there was no increase in weight or fineness for those offered more than 4 cm. Nutritional treatments post parturition had no significant effects on wool characteristics. There seems to be little benefit, in terms of wool growth and wool processing characteristics, of offering twin- or triplet-bearing ewes a sward height of more than 4 cm. }, issn = {1176-5283}, author = {Sherlock RG and Torbatinejad N and Kenyon PR and Morris ST} } @conference {41491, title = {Effect of timing of insemination of dairy cows with liquid semen relative to the observation of oestrus}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {140-142}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Many studies have confirmed that the best conception rates are obtained when cows are inseminated from mid to late oestrus. The conclusions of Trimberger, (1948) has led to the universally accepted AM - PM schedule for inseminating cows. The guideline suggests that cows found in oestrus during the AM period be inseminated at the following PM and the cows in oestrus at the PM be inseminated the following AM. Variations of this rule have been tested with single and multiple AI during oestrus periods and once daily AI after the AM milking with no adverse effect on conception rates. The objective of this study was to determine the effect of time of insemination on Non Return Rates (NRR{\textquoteright}s) in a sample of seasonal breeding New Zealand dairy cows submitted for insemination once a day after following the AM - PM guideline. Two hundred farms participated in this trial with over 12,000 animals representing Friesian, Jersey and Cross breeds were included in this dataset. The farmers were asked to keep accurate records on when cows were first detected in oestrus during the first two weeks of mating. There was no significant difference in 18 to 24 day non return rates for all cows observed in heat at the two time periods and inseminated the following AM (71.8\%, PM and 71.6\% AM respectively, p = 0.18). There was no effect of bulls or age of cows. A nominal effect of breed of cow was observed. In conclusion, there was no effect on NRR when cows were inseminated at the one time period after AM milking whether they were first observed in heat the previous PM or the AM just prior to insemination. }, issn = {1176-5283}, author = {Vishwanath R and Melis J and Johnson DL and Xu ZZ} } @conference {41516, title = {The effect of weaning date, gastro-intestinal nematode challenge and nutrition on beef calf growth}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {257-261}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Two experiments were conducted to understand the interactions between calf weaning date, level of nutrition and parasite challenge. In the first experiment, spring-born calves were weaned at 6 or 9 months of age (early or late weaning) and subject to natural parasite challenge, or natural plus an additional dose of 7500 infective larvae/day. Late weaned calves (with cows) also had either high or low pasture allowance treatments imposed. When calves were 9 months of age, calf liveweights (kg) were 253, 302 and 277 (SED 3.9) for the early wean/high nutrition, late wean/high nutrition and late wean/low nutrition treatments respectively and high and low nutrition cow liveweights were 494 and 479 kg (SED 4.8) respectively. At 9 months of age, early weaned calves showed higher faecal egg counts (P<0.05). Dosing with additional parasitic larvae had no effect on early weaned calves, but lowered late weaned calf weights. In the second experiment, calves were weaned at 6 months of age or left un-weaned until the age of 9 months when all calves were slaughtered. Un-weaned calves showed lower gastro-intestinal worm counts than early weaned calves. In both experiments, late weaned calves showed substantial liveweight advantage and lower parasite burdens. Reducing the nutrition of late weaned calves and cows reduced the size of this liveweight benefit. Later weaning is a management option for farmers seeking to reduce reliance on anthelmintic drenches without the associated production loss. }, issn = {1176-5283}, author = {Boom CJ and Sheath GW and Vlassoff A} } @conference {41474, title = {The effect on sheep reproduction of grazing willow fodder blocks during drought}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {67-71}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {A trial was conducted in the summer/autumn of 2003 to determine the effect of grazing on willow fodder blocks (6,000 stems/ha) during mating, relative to control ewes grazed on drought pasture, upon ewe production and reproduction. Grazing occurred over 10 weeks, from 19 February including 3 cycles of mating, with ewes randomly assigned to four treatment groups each of 100. The treatments were short drought pasture (typical of drought pasture), long drought pasture (typical of the pasture growing in the willow fodder blocks), short drought pasture with restricted willow access (restricted access) and full access to willow fodder blocks (fenced on the willow all the time; full access). After mating the four groups were joined together and managed as one mob until weaning. Substantial live weight loss occurred in the short control group (101 g/day), as would occur in severe drought conditions and reproductive rate was low. Ewes in the full access group had significantly (P<0.05) less live weight loss of 40g/day, with reproductive rate increased by approx 20\% units (P<0.05). The increase in reproductive rate in the group with full access to willow fodder blocks was due to increases in fecundity, with more ewes giving birth to twin lambs. Live weight loss during mating in the long control and restricted access groups was intermediate between the short control and full access groups (75-86 g/d) and significantly different from either (P<0.05); reproductive rate was also intermediate between the short control and full access groups but was not significantly different from either (P>0.05). Grazing willow fodder blocks with full access during times of drought can be used to reduce the decline in reproductive rate, which occurs when ewes are mated on drought pastures. }, issn = {1176-5283}, author = {Pitta DW and Barry TN and Lopez-Villalobos N and Kemp PD} } @conference {41494, title = {Effects of a commercial feed containing conjugated linoleic acid on the production of milk components and the value of milk}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {150-154}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {This study was to evaluate changes in cow productivity and milk value from feeding a rumen-protected form of CLA to pasture-fed dairy cows in early lactation. 30 New Zealand Friesian dairy cows were randomly assigned at calving to either 0g (control) or 120g/d of a commercial rumen protected feed containing CLA from 4 days post-calving for 16 weeks. Milk yield and composition data was collected weekly. A simulation model was used to calculate yield of dairy products based on accumulated yields of milk and its components per cow during the experimental period. Feeding CLA reduced (P<0.001) fat concentration (3.1\% vs 4.2\%) and increased (P<0.05) milk yield (2688 kg vs 2423 kg), and protein yield (89.9 kg vs 81.2 kg). The effect of CLA on milk fat concentration was reflected in the yield of dairy products and milk value. Milk from cows fed CLA had less (P<0.01) excess of fat sold as butter (48.4 vs 69.4 kg butter). The value of milk ($/kg MS) was higher (P<0.001) from cows fed CLA than from control cows at 2002/03 prices ($3.87 vs $3.66) and when butter price was low ($3.56 vs $3.24). }, issn = {1176-5283}, author = {Back PJ and Lopez-Villalobos N} } @conference {41471, title = {Efficacy of pre-mating supplementation with mono propylene glycol on reproductive performance of cows in commercial dairy herds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {53-57}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Prolonged postpartum anoestrous intervals (PPAI) are the major source of infertility in New Zealand dairy cows. Postpartum supplementation with mono propylene glycol (MPG) was previously shown to reduce PPAI in heifers. The present experiment tested this treatment in four large commercial dairy herds. During the six-week period preceding the planned start of mating (PSM; week 0), cows were drenched either once (1xMPG) or twice (2xMPG) daily with 200 ml MPG, or served as untreated controls (CON). Analyses were confined to the group of cows that were anoestrus at Week {\textendash}6 or calved between Week {\textendash}6 and Week {\textendash}4 relative to PSM (n = 662 to 669 per treatment). Change in body condition score between Week {\textendash}6 and Week {\textendash}1(∆BCS), and proportion of cows that were anoestrus at Week {\textendash}1 were influenced by herd, age and time of calving (P<0.05) but not by treatment (P>0.1). Treatment did not influence the proportion of anoestrous-treated cows inseminated after oestrus detection (n =263), or the pregnancy rate among all cows. Pre-mating supplementation with MPG did not influence ∆BCS, the percentage of cows that were anoestrus at Week {\textendash}1, or rates of submission and conception. Change in BCS affected both milk yield and pregnancy rates, where cows that gained BCS produced less milk but showed higher 6-week pregnancy rates. This study highlighted that key factors influencing the percentage of anoestrus at PSM are cow age, time of calving and management of the herd. }, issn = {1176-5283}, author = {Tunon GE and Taufa VK and Burke CR and Holmes CW and Chagas LM} } @conference {41514, title = {Embryo transfer for improved feed conversion efficiency in cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {246-251}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Two experiments were conducted to understand the interactions between calf weaning date, level of nutrition and parasite challenge. In the first experiment, spring-born calves were weaned at 6 or 9 months of age (early or late weaning) and subject to natural parasite challenge, or natural plus an additional dose of 7500 infective larvae/day. Late weaned calves (with cows) also had either high or low pasture allowance treatments imposed. When calves were 9 months of age, calf liveweights (kg) were 253, 302 and 277 (SED 3.9) for the early wean/high nutrition, late wean/high nutrition and late wean/low nutrition treatments respectively and high and low nutrition cow liveweights were 494 and 479 kg (SED 4.8) respectively. At 9 months of age, early weaned calves showed higher faecal egg counts (P<0.05). Dosing with additional parasitic larvae had no effect on early weaned calves, but lowered late weaned calf weights. In the second experiment, calves were weaned at 6 months of age or left un-weaned until the age of 9 months when all calves were slaughtered. Un-weaned calves showed lower gastro-intestinal worm counts than early weaned calves. In both experiments, late weaned calves showed substantial liveweight advantage and lower parasite burdens. Reducing the nutrition of late weaned calves and cows reduced the size of this liveweight benefit. Later weaning is a management option for farmers seeking to reduce reliance on anthelmintic drenches without the associated production loss. }, issn = {1176-5283}, author = {Smeaton DC and Scott ML and Webby RW and McGowan L and Cameron C and Brooky A} } @conference {41469, title = {Expression of the tight junction protein zonula occludens-1 during mammary engorgement}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {43-47}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {An increase in tight junction (TJ) permeability occurs during extended milking intervals and is associated with reduced milk secretion. This paper examines temporal changes in the expression of a major TJ protein, zonula occludens-1 (ZO-1), during mammary engorgement. Alveolar mammary tissue was collected from 52 mid-lactation dairy heifers at 0, 6, 12, 18, 24, 36 and 72 h, and at 8 d following abrupt cessation of milking (n >= 6 cows per time point). ZO-1 protein expression significantly decreased during mammary engorgement (P<0.05). Similarly, ZO-1 mRNA expression had halved by 36 h to 8 d post-milking (P<0.05). In a second trial, alveolar tissue was collected from the udder halves of late-lactation dairy cows (n = 4) that were milked unilaterally, either once-daily or twice-daily for 4 days. A 1.7-fold increase in ZO-1 mRNA expression was detected after once-daily milking, compared with twice-daily milking (P<0.05). The down-regulation of ZO-1 during mammary engorgement is consistent with increased TJ permeability. However, the up-regulation of ZO-1 mRNA expression during short-term once-daily milking suggests that TJ function is repaired as the mammary gland adjusts to the extended milking interval. In conclusion, we have identified changes in ZO-1 critical to TJ function in bovine mammary glands. }, issn = {1176-5283}, author = {Cooper CV and Stelwagen K and Singh K and Farr VC and Prosser CG and Davis SR} } @conference {41490, title = {Factors affecting non-return rate in dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {138-139}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Non-return rate (NRR) to artificial insemination (AI) gives a measure of bull fertility early in the mating season. Calving rate can be biased due to culling and is available too late in the season to be useful for detecting sub-fertile bulls. A current limitation, in the New Zealand dairy industry, to calculating the NRR for bulls is that it is largely based on raw averages of binary data (returned or not) and using only qualifying matings. For example, for an 18-24 day NRR, a mating would qualify if the insemination occurred at least 24 days prior to the end of the observation period and this would utilise only about 42\% of the available mating information. Currently no account is taken of environmental factors that may affect NRR (e.g. region, breed of cow) and of the number of inseminations for each bull. The variable of interest is the time interval between the mating date for a cow and an end-point. For a cow returning to service during the AI mating period, the end-point is the date of return to service. For non-returns within the mating period, the end-point is the final AI mating date for the herd. The former type of mating record is uncensored while the latter is a censored record in the sense that a possible return event may not be observed. }, issn = {1176-5283}, author = {Johnson DL} } @conference {41515, title = {Factors associated with calving difficulty in embryo transfer mated cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {252-256}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Data were collected from 249 cows over 2 years at Whatawhata Research Centre on pelvic area, weight and breed of embryo transfer mated cow, calf birth weight, breed and a defined calving difficulty score. Cow liveweight and pelvic area were significantly correlated (R2 = 0.56, P< 0.05), but cow liveweight and calf birth weight were not (R2 = 0.07, NS). Cow pelvic area and calf birth weight were also not related (R2 = 0.04, NS). In July of each year, the Jersey cows were 119 kg lighter (P<0.001), had a smaller pelvic area (264 vs. 322 cm2, P<0.001) and more calving difficulties (26 vs. 5\%, P<0.001) than Hereford x Friesian (HxF) cows. Across breeds, pelvic area (P<0.01) and cow liveweight (P<0.001), when fitted individually, were negatively associated with the probability of a cow having an assisted calving. On its own, the impact of calf birth weight was NS, although it explained additional variation (P<0.05) if cow liveweight was in the model. Within the range of calf breeds (NS) we used, we predict that any of recipient breed, cow liveweight or pelvic area (in decreasing order of reliability) could be used to reject cows at ET that might cause problems at calving although errors of estimation will result in wasteful rejection of cows and will not eliminate calving problems. }, issn = {1176-5283}, author = {Smeaton DC and Scott ML and Webby RW and Cameron C and McGowan L and Brooky A} } @conference {41464, title = {Fetal programming of postnatal phenotype and obesity - experimental evidence from biomedical research}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {24-29}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {The evidence for the fetal origins of adult disease (diabetes, cardiovascular) is reviewed. There is evidence of a disturbed endocrine communication between the hypothalamus, adipose tissue and the endocrine pancreas in the pathogenesis of programming-induced obesity. Hypercaloric nutrition during postnatal life greatly amplifies prenatal effects on metabolic abnormalities, obesity, overeating and diminished exercise behaviour. Fetal programming research offers a novel approach to investigate the mechanistic basis of metabolic disorders. }, issn = {1176-5283}, author = {Krechowec SO and Vickers MH and Breier BH} } @conference {41524, title = {Flystrike in lambs selected for resistance or susceptibility to ryegrass staggers, when challenged with high or low endophyte pastures}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {297-299}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Research has shown that incidence of flystrike is reduced in sheep grazing low endophyte ryegrass. This experiment was designed to test the hypothesis that where lambs are bred specifically for resistance to ryegrass staggers (RGS), their susceptibility to flystrike on the body should be correspondingly low, even when challenged with high levels of endophyte. Ewe and ram lambs were sourced from two lines, one selected for resistance (n = 85) and the other for susceptibility (n = 143) to ryegrass staggers. A further group of lambs (n = 63) produced by intercrossing the two lines was included. The lambs were run in 2 mobs, on high and low endophyte pasture, and monitored daily for signs of flystrike on the body. During the course of the experiment, susceptible (n = 34) and resistant (n = 1) lambs suffering from clinical ryegrass staggers had to be removed from the high endophyte pasture. These were excluded from the analysis. Ram lambs made up the majority of animals removed. Only ram lambs were flystruck on the body, particularly around the scrotal area. Significantly more resistant ram lambs (7 of 49) were flystruck than susceptible (3 of 85) or intercross ram lambs (2 of 27), regardless of pasture endophyte level (P < 0.1). More lambs (P < 0.1) were flystruck grazing ryegrass with high endophyte (n = 9) than low endophyte (n = 3). The only lambs flystruck while grazing non-endophyte pasture were RGS resistant rams. In contrast to the hypothesis, this experiment indicates that selection of animals for resistance to RGS may exacerbate their susceptibility to flystrike. The evidence presented here supports the literature that sheep grazing high endophyte pasture are more susceptible to flystrike. The question for farmers is whether their selection priority should be for pasture with resistance to insect pests, or for stock with resistance to RGS, or both. }, issn = {1176-5283}, author = {Young SR and Scobie DR and Morris CA and Amyes NC} } @conference {41505, title = {Formation and excretion of phenol flavour compounds in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {203-207}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Rumen, plasma and urinary concentration of the undesirable phenol flavour compound 4-methylphenol was measured in two rumen-fistulated Romney wethers fed perennial ryegrass. Following a one week adaptation period, samples were collected at ca. 1 hr intervals after feeding on two sampling days one week apart. Maximal concentration of 4-methylphenol in the rumen, blood and urine was reached at ca. 2, 3, and 4.5 hr respectively, declining to a minimal concentration by 9 hr (15\% of maximum), 11 hr (16\%), and 18 hr (<1\%) respectively. Thus phenol compounds formed in the rumen are cleared rapidly and efficiently by excretion into the urine. In a separate trial the absorption and excretion of the exogenous phenol, thymol, was measured. Four groups of 4 lambs grazed on pasture were dosed daily with either a control or 3 different levels of thyme slurry for two weeks. After one week of dosing spot urine samples were collected on two consecutive days. Upon completion of the two week dosing period the animals were slaughtered and subcutaneous fat samples collected. The concentration of thymol (conjugates) in the urine was highly correlated with the thyme dosage (r=0.848, P<0.001), but there was no significant correlation between dose level and the concentration of (free) thymol in the fat. These results suggest that the concentration of phenol flavour compounds in ruminant products is affected by the efficiency of conjugation and excretion as much as by their formation in the rumen. }, issn = {1176-5283}, author = {Fraser K and Lane GA and Schreurs NM and Tavendale MH and Keogh RG and Kirk MR and McNabb WC} } @conference {41480, title = {Friesian Jersey crossbred trial: Generating phenotypes for the discovery of quantitative trait loci}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {92-95}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {The breeding of improved varieties of agriculturally important species requires constant effort and innovation. The ways we in New Zealand use emerging technologies to maintain our low-cost, low-input, sustainable, pastoral agricultural systems are extremely important. When it comes to developing elite varieties and strains of ryegrass we have been, until very recently, disrupting much to achieve little: we rely on chance to find the right combinations of traits in our breeding lineages, whether animal germplasm or plants cultivars. The use of Cisgenics{\AE}, where heritable material is moved only within a species by either traditional or modern biotechnological means offers a better way for ryegrass breeding in line with a key principle of science and economics.}, issn = {1176-5283}, author = {Spelman RJ and Hooper JD and Stanley G and Kayis SA and Harcourt S} } @conference {41495, title = {Fumarate reduces methane production from pasture fermented in continuous culture}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {155-159}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {This experiment tested the hypothesis that addition of an organic acid (fumarate) would increase the energy captured from a pasture diet during ruminal fermentation. Pasture was fermented with 0, 10, 20, or 30 mM of fumarate constantly infused into four dual-flow continuous culture fermenters. Digestion characteristics responded linearly (P<0.05) as fumarate increased from 0 to 30 mM. Increasing fumarate from 0 to 30 mM reduced (P=0.057) methane production by 38\%, and reduced the ratio of acetate:propionate (2.4 v.s. 1.5). Concentrations of propionate and total volatile fatty acids increased by 74\% and 19\%, respectively. These results were consistent with fumarate acting as an electron-accepting intermediary in the succinate-propionate pathway. The addition of fumarate increased energy capture from a pasture diet by improving the supply of glucogenic compounds and reducing losses to methane emissions. }, issn = {1176-5283}, author = {Kolver ES and Aspin PW and Jarvis GN and Elborough KM and Roche JR} } @conference {41481, title = {Future genetic progress of dairy cattle in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {96-100}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = { Significant lifts in profitability have been achieved by New Zealand dairy farmers through the inclusion of increasing amounts of maize silage into a pasture based system. Most of this maize is grown off the dairy unit on farmer owned or leased runoff blocks or by contract growers. While there is still significant scope to improve dairy farm productivity by increasing maize silage input levels, there is considerable opportunity to also improve dairy farm productivity by reducing feed costs through improving maize silage yields, increasing milk output by lifting maize silage nutritional quality and improving agronomic stability of maize silage offering higher yields over a wider environmental range. Traditional plant breeding, genetic engineering and advances in agronomic management all have the potential to impact production potential and profitability of maize silage in New Zealand dairy farm systems.}, issn = {1176-5283}, author = {Montgomerie WA} } @conference {41488, title = {Genetic and phenotypic relationships between milk protein percentage, reproductive performance and body condition score in New Zealand dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {127-131}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Recent research from the Australian In-Calf and New Zealand Monitoring Fertility projects have demonstrated that low milk protein percentage in early lactation is phenotypically linked to poor reproductive performance. The purpose of this study was to quantify the phenotypic and genetic relationship between body condition score (BCS), protein percentage (and other milk production traits) and the reproductive measures used to predict the female fertility breeding value in New Zealand{\textquoteright}s Animal Evaluation System: probability of mating in the first 21 days of a herd{\textquoteright}s mating period (PM21) and the probability of having a calf born to AI (CAI). Data on 99,870 first lactation cows, recorded as part of Livestock Improvement{\textquoteright}s and Ambreed{\textquoteright}s progeny test schemes were used for both a phenotypic analysis and to estimate genetic parameters. Effects of breed, heterosis, BCS, protein percentage and dairy conformation were statistically significant in logistic regression analyses on both CAI and PM21. Genetic correlations between protein percentage and PM21 and CAI were 0.18 and 0.20 respectively and genetic correlations of BCS and PM21 and CAI were 0.48 and 0.38 respectively. These results show that selection for protein percentage is unlikely to have a large effect on reproductive performance, while BCS is a promising tool to aid in selection for improved fertility. }, issn = {1176-5283}, author = {Harris BL and Pryce JE} } @conference {41517, title = {Gross margin analyses of using cloned embryos in cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {262-267}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {A spreadsheet model was developed that evaluated the gross margin (GM) profitability of clone embryos placed by embryo transfer into recipient cows compared to Hereford x Friesian cows naturally mated to a high growth rate finishing sire. Biological parameters in the model included variables of performance such as losses at various points through pregnancy, calving and rearing and cow losses and calving difficulty. Variance (SD) and correlation information associated with gestation length, birth weight and calf liveweight gain were included. Allowance was made for the extra costs associated with clone ET and the possibility of lower pregnancy rates. To provide a stable result, the model was based on a 1000-cow herd. Assuming 50\% of clone ET cows are diagnosed pregnant at 28 days after ET (35 days of gestation) we determined that clone embryos must sell for NZ$84 each to break even with the natural mating system, assuming 80\% of clones surviving to weaning would sell in niche markets at 3 times the price/kg liveweight of their cohorts. When all clones attracted the premium, the breakeven price was $142/embryo. The coefficient of variation (CV) of GM profit was 6\% for the clone herd vs. 2\% for the naturally mated herd. For smaller herds (say 100 cows), with a proportionately lower herd GM, the CV of GM and therefore risk, was higher, at 17\%. At weaner clone premiums ranging from 2.25 to 4 times the normal weaner price/kg, the breakeven price ranged from $0 to $195/embryo respectively if 80\% of the clones received the premium and $10 to $280 when all weaned clones received the premium. }, issn = {1176-5283}, author = {Smeaton DC and Woodward SJR and Wells DN and Smith JF} } @conference {41461, title = {Growth and development contract session}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {17}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

In 2003 the Centre of Research Excellence (CoRE) for Growth and Development was formed. The purpose is to conduct research into growth and development, focussing particularly on the issues of pre- and post-natal growth and its implications for human health.
The medical challenges for the developed world are those associated with the nutritional environment, obesity and the associated illnesses of diabetes and cardio-vascular disease. There is evidence linking the propensity for these diseases to the nutritional status of the fetus in the first trimester of pregnancy and the interaction of this status with nutrition in the immediate post-natal period. In this respect the problem differs from the issues considered by animal production. Here the last trimester of pregnancy has received the most attention, and few domestic animals live long enough for cardio-vascular problems to arise. Nevertheless the skills and methods of investigation developed by animal scientists can be applied to these new problems.
Animal production research and medical science have much to offer each other, but with a few notable exceptions this potential has not been realised. A cursory look at the references listed by the authors in this contract shows little evidence of contact. One of the goals of the CoRE is to promote this interaction. This contract session with the New Zealand Society of Animal Production has two goals. First, to make animal scientists aware of the questions facing medical scientists with respect to early growth and development, the focus of the CoRE effort. Second, to encourage individuals to make contact and build future networks with the aim of developing joint projects.

}, issn = {1176-5283}, author = {Pleasants AB} } @conference {41485, title = {Heritability of puberty traits in dairy heifers in commercial herds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {115-117}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Age and weight at puberty (first behavioural oestrus) are known to be heritable traits in experimental beef and dairy cattle. The recording required is usually labour-intensive, and may also be expensive if serial blood samples are taken to estimate progesterone concentrations. Our objective in this study was to ascertain whether a less labour- intensive approach for estimating age at puberty (AP) would still provide enough statistical power to show genetic variation among sire groups of Friesian and Jersey heifers grazing in large groups. Commercial heifers (n = 797) were born in the late winter/early spring of 2002, and were predominantly the result of artificial insemination (AI) matings. They were reared to weaning in six herds, and then grazed in five herds through 2003. Tailpaint was applied to heifers at visits to the grazing herds at 4-6 week intervals, and tailpaint loss was recorded at each visit to determine approximate date at puberty. Birth dates were known, and hence AP was calculated. The heritability of yearling live weight (W12) was used as a control measure. From four of the herds (n = 453), there were animals by 13 widely-used AI sires (9 Friesian and 4 Jersey), and 10 other sire groups were represented with at least 5 daughters each. The phenotypic standard deviations for AP and WP were 48 days and 34 kg, similar to that found in New Zealand experimental beef cattle herds. The pooled within-breed heritability estimates for AP, WP and W12 were 0.09 {\textpm} 0.10, 0.21 {\textpm} 0.14 and 0.24 {\textpm} 0.15, respectively. Confounding of AI sire group with date of birth of heifer was encountered. The breeding-value difference in AP between the top 7 and bottom 6 of the widely used AI sires was 15 days, or 1.05 genetic standard deviations. In conclusion, recording AI calves in large grazing herds may be a practical method of getting access to puberty data, but more frequent visits to each herd would probably be needed to reduce the noise, and increase the heritability for AP and WP. }, issn = {1176-5283}, author = {Morris CA and Hickey SM} } @conference {41508, title = {Hogget mating in New Zealand - a survey}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {217-222}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Currently less than 30\% of all hoggets are presented for mating in New Zealand. This would suggest that there are a number of disadvantages to this management practise. However to date it has not been accurately established what farmers perceive as the disadvantages of hogget mating and the relative importance of each of these disadvantages. A questionnaire was sent to New Zealand sheep farmers which asked a series of questions regarding farm type, size, farm class, flock type, flock size and the intended use of hogget mating in 2002 and its use in the past. Those farmers who were not intending to mate hoggets in 2002 were also asked to indicate the importance, on a scale of 1.4, of 11 stated reasons for not hogget mating. A total of 1981 questionnaires were returned and used in the present study from a total of 14,000 sent to farmers. Descriptive analysis indicated negative effects on two-tooth performance and lack of additional feed were the two main reasons for not mating hoggets. The least important variables were lack of experience and the need for extra rams/teasers. The intended use of hogget mating differed based on farm class, farm size, ewe flock size and farm and flock type. Farmers were more than twice as likely to mate hoggets in 2002 if they had a mixed-bred flock in comparison to a straight-bred flock and more than twenty times more likely to mate hoggets in 2002 if they had mated hoggets in previous years. This study indicates that farmers perceive impaired two-tooth performance as a major reason for not hogget mating, even though research to date would indicate this is not that case. Therefore either improved technology transfer is required or the effects of hogget mating on two-tooth performance need to be re-visited. }, issn = {1176-5283}, author = {Kenyon PR and Morris ST and Perkins NR and West DM} } @conference {41504, title = {Ill-thrift in young growing cattle and sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {197-202}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {A questionnaire survey was designed to gauge consumer interest in goat meat. The questionnaire was responded to by 98 households living in or near Tokyo. The main results of the survey are as follows. 1) Impression of goat meat; 61\% of the respondents indicated that goat meat was {\`\i}not common in their home{\^\i}. 2) Consumer experience; only 16\% of the respondents had experience of eating goat meat and they felt goat meat is {\`\i}smelly{\^\i}(50\%), {\`\i}tender{\^\i}(38\%) and {\`\i}delicious{\^\i}(31\%). 3) The two main reasons why consumers have not eaten goat meat were {\`\i}lack of purchasing opportunity{\^\i}(78\%) and {\`\i}don{\'\i}t feel like eating it{\^\i}(18\%). 4) Options to promote goat meat consumption; 52\% of respondents who have not eaten goat meat were prepared to purchase if it was available in the supermarket at a reasonable price and if recipes were added with the meat package. 5) Reasons for people not purchasing goat meat included {\`\i}dislike of new meat{\^\i} and {\`\i}pity for the goat{\^\i}. These results show that goat meat can be promoted to the Japanese households as {\`\i}a new product{\^\i} if the price is reasonable and recipes are added to the package. However, a considerable number of market strategies need to be implemented to achieve the acceptance of goat meat by Japanese consumers.}, issn = {1176-5283}, author = {Litherland AJ and Layton DL and Boom CJ and Knight TL and Hyslop M and Lambert MG and Cook TL} } @conference {41470, title = {Influence of feeding level after drying off on incidence of mastitis and keratin plug formation in dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {48-52}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Prolonged postpartum anoestrous intervals (PPAI) are the major source of infertility in New Zealand dairy cows. Postpartum supplementation with mono propylene glycol (MPG) was previously shown to reduce PPAI in heifers. The present experiment tested this treatment in four large commercial dairy herds. During the six-week period preceding the planned start of mating (PSM; week 0), cows were drenched either once (1xMPG) or twice (2xMPG) daily with 200 ml MPG, or served as untreated controls (CON). Analyses were confined to the group of cows that were anoestrus at Week {\~n} 6 or calved between Week {\~n} 6 and Week -4 relative to PSM (n = 662 to 669 per treatment). Change in body condition score between Week {\~n} 6 and Week - 1(∆BCS), and proportion of cows that were anoestrus at Week {\~n}1 were influenced by herd, age and time of calving (P<0.05) but not by treatment (P>0.1). Treatment did not influence the proportion of anoestrous-treated cows inseminated after oestrus detection (n =263), or the pregnancy rate among all cows. Pre-mating supplementation with MPG did not influence ∆BCS, the percentage of cows that were anoestrus at Week {\~n}1, or rates of submission and conception. Change in BCS affected both milk yield and pregnancy rates, where cows that gained BCS produced less milk but showed higher 6-week pregnancy rates. This study highlighted that key factors influencing the percentage of anoestrus at PSM are cow age, time of calving and management of the herd. }, issn = {1176-5283}, author = {Summers EL and Lacy-Hulbert SJ and Williamson JH and Sugar BP} } @conference {41484, title = {Influence of material and sire effects on antibody response following clostridial vaccination of Friesian-Jersey crossbred calves}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {110-114}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {As part of an ongoing project to identify quantitative trait loci (QTL) for economically important traits in New Zealand dairy cows, a vaccine trial was conducted to measure the antibody response of 10 week old Friesian-Jersey crossbred calves to two antigenic compounds of a clostridial vaccine (Clostridium novyi B and Clostridium tetani toxoids). Blood samples were collected from 469 calves prior to vaccination at 10 weeks of age, prior to re-vaccination at 13 weeks of age and at 16 and 22 weeks of age. ELISA assays using conjugated rabbit anti-bovine IgG were conducted for both toxoids. Correlations and explanatory variables were calculated using correlation and general linear model (GLM) procedures in SAS. Antibody response to both toxins were relatively low after the first vaccination (week 13), but were boosted to high levels after revaccination (week 16). GLM analysis revealed a moderate sire effect contributing to the variability seen in the 13 week test against C. tetani (P=0.001) and the 16 week test against C. novyi (P=0.01). This variation in individual antibody response will be used in future research to identify genetic factors controlling the acquisition of immunity. }, issn = {1176-5283}, author = {Harcourt SJ and Buddle BM and Hamel K and McNaughton LR and Spelman RJ} } @conference {41523, title = {Justifying the appropriate length for docking lambs{\textquoteright} tails - a review of the literature}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {293-296}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {It is generally accepted that tail docking is beneficial in farming systems where sheep are predisposed to dag formation and flystrike, but that it is a stressful procedure. Although there have been many studies of tail docking, relatively few have looked at the effects of different tail lengths. The incidence of flystrike depended on tail length, being least in medium-, and greatest in short-tail docked sheep. Short-tail docked ewes had higher rates of carcinoma of the vulva and short-tail docked lambs had a greater incidence of rectal prolapse. In some cases, increased tail length was associated with increased dags, and with longer tails crutching and shearing effort was greater. There apparently have been no studies documenting the effects of docking at different lengths on the welfare of the lamb at the time of docking, on muscle anatomy, or on defecation and urination. Furthermore, the results obtained in some studies were confounded by differences in breed (e.g. Merino) and mutilations (e.g. mulesing), which question the validity of extrapolating their conclusions to New Zealand conditions. }, issn = {1176-5283}, author = {Fisher MW and Gregory NG and Kent JE and Scobie DR and Mellor DJ and Pollard JC} } @conference {41477, title = {Landcorp Farming Lecture : Nutritional opportunities for longer-term, sustainable, ruminant production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {77-83}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {In the present era of {\textquoteleft}sustainability{\textquoteright} our ability to deliver longer-term, environmentally-friendly ruminant production systems, based on forage feeding with only limited (strategic) use of concentrates, might well depend on the ability of animal scientists to embrace multi-disciplinary approaches that can capitalise on the power of the modern technologies. Whilst environmental issues tend to dominate present thinking on sustainable systems, the longer-term viability of these systems may depend on economic aspects such as an ability to improve the efficiency of converting forage protein into animal product and an ability to sell these products to the health-conscious consumer. Communication between animal and plant scientists has already led to encouraging reports from collaborations in which forage breeders, utilising genomics-based marker-assisted selection techniques, have developed forages with higher water-soluble carbohydrate content which can promote increased milk production in dairy cows and live weight gain in lambs and beef steers. Similar communications between animal and biomedical scientists may provide opportunities for enhancing the {\textquoteleft}healthy-eating{\textquoteright} image of ruminant products. Several examples (e.g. n-3 polyunsaturated fatty acids, conjugated linoleic acids, selenium, specific milk proteins and the protein-linked delivery of calcium and phosphorus in milk and iron in meat) are used to indicate how current knowledge on the relationships between nutrient intake and the development of non-communicable diseases such as heart disease and cancer might be badged to help promote animal products as {\textquoteleft}healthy eating{\textquoteright} options. }, issn = {1176-5283}, author = {MacRae JC} } @conference {41472, title = {Is lithium a candidate to modify rutting behaviour in stags?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {58-62}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Preliminary experiments assessed the potential of lithium to moderate the effects of the rut. Young (5-9 month old) stags were used to determine the kinetics of lithium in deer, establish appropriate dose rates, evaluate the opportunity for self-medication and to test whether behaviour would be modified. The relationship between lithium dose rate and plasma lithium concentration was established from acute administration (5 dose rates, 2 animals per dose) and confirmed with continuous medication for 31 days. A daily dose of 0.6 mmol Li/kg W (as LiCl) achieved a mean plasma Li concentration of (0.78 {\textpm} 0.04 mmol/l), which was within the therapeutic range (0.5{\textendash}1.5 mmol/l). This daily dose, offered in drinking water (11.2 mmol Li/l as LiCl) to a group of (n=10) young stags induced a decline in both water (14\%) and feed (12\%) intake which was almost recovered after 4 weeks of self-medication. Liveweight gain averaged 252 {\textpm} 27 g/d for +Li animals compared with 263 {\textpm} 21 g/d for the -Li group (NS). Lithium treated stags moved more freely through a maze than did -Li stags, with 60\% of the animals completing the maze compared with only 10\% of the -Li group. There was no significant difference in the behaviour of +Li and -Li groups to the introduction of a unfamiliar stag or in their response to human handling. This work lays the foundation for studies on the potential for lithium therapy to modify the rut in adult stags. }, issn = {1176-5283}, author = {Prouting MF and Nicol AM and Keeley MJ} } @conference {41499, title = {Manipulating lamb birth weight and survival rate in singletons born to hoggets}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {175-178}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Lambs born to hoggets tend to be relatively lightweight at birth (Drymundsson, 1973; McMillan \& McDonald, 1983) and display low survival rates to weaning (McCall \& Hight 1981; McMillan \& McDonald, 1983). In addition the incidence of singletons in hoggets often exceeds 92\% (McCall \& Hight, 1981; McMillan \& McDonald, 1983). Therefore management procedures that improve both birth weight and survival of singleton lambs should have a significant effect on returns. Severe under nutrition during pregnancy of mature ewes can lead to reduced ewe and lamb performance (Rattray 1986), which can negatively affect lamb survival. However to date minimal research under New Zealand{\textquoteright}s pastoral conditions has been undertaken in hoggets. In contrast to the mature ewe, it is also advantageous for the hogget to be increasing in conceptus-free live weight during pregnancy if lifetime performance is not to be negatively affected. Interestingly, under concentrate feeding regimes in the United Kingdom it has been reported that a high level of hogget nutrition in pregnancy, actually reduces both lamb birth weight and survival (Wallace et al., 1996). Shearing mature ewes in mid- to late-pregnancy has been shown to differentially increase singleton- (Morris et al., 2000; Kenyon et al., 2002a) and twin-lamb birth weights (Morris \& McCutcheon, 1997; Morris et al., 1999; Kenyon et al., 2002b). Mid-pregnancy shearing has tended to increase twin-lamb survival rates (Morris et al., 1999; Kenyon et al., 2002b) but has been found to decrease singleton survival rates in one of four studies (Kenyon 2002). The effect of mid- to late-pregnancy shearing of hoggets has not been examined under pastoral conditions in New Zealand. Due to the low rate of twin pregnancies in hogget{\textquoteright}s the chance of achieving a positive affect from mid-pregnancy shearing on both a lamb birth weight and survival may be low. The aims of these studies were to determine if hogget live weight change and shearing treatment during pregnancy could be used to manipulate singleton lamb birth weight and survival. }, issn = {1176-5283}, author = {Kenyon PR and Morris ST and West DM and Stafford KJ and Corner RA and Ottema K and Burnham DL} } @conference {41487, title = {Mate selection to control inbreeding and maximise farm profit of commercial dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {122-126}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {The objective of this study was to demonstrate the potential benefits of computerised mate selection in a commercial crossbred dairy herd of 411 cows mated to 10 Holstein-Friesian and 10 Jersey bulls. Mate selection was carried out using an evolutionary algorithm to perform single- or multiple-objective optimisation to maximise farm profit ($/4.5 t DM) and/or minimise inbreeding level of progeny. Restrictions were placed on the total number of mating pairs, the maximum number of matings per bull and per cow. Selection and mate allocation of bulls and cows at random produced progeny with average farm profit of $94 and inbreeding level of 1.70\%. Mate selection applied to maximise farm profit yielded a mating set with an average farm profit of $181 and inbreeding level of 2.07\%. Mate selection applied to minimise inbreeding level selected a mating set with average farm profit of $65 and inbreeding level of 0.03\%. Mate selection applied to optimise farm profit and minimise level of inbreeding with a weighted ratio of 1:1, resulted in a mating set with average farm profit of $176 and inbreeding level of 0.44\%. The results demonstrate that in the short term, inbreeding can be controlled at the same time as maximising farm profit using a computerised mating selection program with multiple-objective optimisation. }, issn = {1176-5283}, author = {Lopez-Villalobos N and Harris BL and Pryce JE} } @conference {41518, title = {Measuring short periods of wool fibre growth using radiolabelling}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {268-271}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Brief periods cannot be measured with traditional autoradiographic methods on wool fibres because the labelled points overlap. A dose of [35S]cysteine was injected into 24 sites across the side of five Lincoln ewes. After 48 hours a second injection was administered to one site on each ewe, followed by an injection into another site every two hours until all 24 sites had been labelled twice. Three days later all 24 sites were injected again. Following autoradiography the distance between radiolabelled points was traced using a digitizer (50 fibres per site). A linear increase in length between points 1 and 2 was observed between sites (r2 = 0.920) and the regression equation showed the fibre increased in length by 29.2 {\textmu}m per site (P < 0.01). However, a linear decrease in length was observed down (P < 0.001) but not along (P = 0.813) the midside over the period delineated by injections 1 and 3. Removing the effect of site gave growth rates that reflected the overall mean of 28.9 {\textmu}m/hour for all sites. This method could be used to determine changes in growth rate over a few hours or the response to a growth factor, hormone or nutrient over a time course of several hours. }, issn = {1176-5283}, author = {Scobie DR} } @conference {41463, title = {Mechanisms linking the somatotropic axis with insulin: Lessons from the postpartum dairy cow}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {19-23}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Growth hormone (GH; synonymous with somatotropin) coordinates nutrient partitioning in dairy cattle by increasing glucose synthesis in liver and mobilizing lipid from adipose tissue. The effects of GH are opposite to the glucose-clearing effects of insulin. It is not surprising, therefore, that physiological mechanisms have evolved which coordinate the actions of both hormones. There appears to be direct communication between the somatotropic axis and the insulin axis. The manifestation of this interaction is clearly evident in postpartum dairy cows where blood GH concentrations are high and blood insulin concentrations are low. Diabetic states in humans [either type 1 diabetes mellitus (insulin-dependent) or type 2 diabetes mellitus (insulin resistance)] also lead to abnormal function within the somatotropic axis; evidence that insulin and GH are closely linked in humans. Cattle and humans share common elements of somatotropin physiology perhaps because common regulatory mechanisms control the expression of key genes within the axis of each species. This review will discuss the mechanisms linking insulin and somatotropin in cattle and humans. Similarities between diabetic states in humans and low-insulin states in postpartum cows will be highlighted. }, issn = {1176-5283}, author = {Lucy MC} } @conference {41511, title = {Milk production and grazing behaviour during early lactation of three strains of Holstein-Friesian dairy cows managed in different feeding systems}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {232-236}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {The objective of this work was to compare individual intake and grazing behaviour of different strains of Holstein-Friesian dairy cows. Strains tested were high breeding worth 1990{\textquoteright}s Holstein-Friesian of overseas (OS90) or NZ origin (NZ90), and a 1970 NZ strain of Friesian (NZ70), farmed under different feeding systems defined by feed allowance per cow per year. Feed allowance ranged from 4.5 to 7.0 t DM cow-1 year-1, based on different stocking rates and supplement inputs. Each system (one strain at one total annual allowance) was managed using a common set of decision rules and all the strains were in similar body condition score (BCS) at calving. Milksolids production, liveweight and BCS were measured routinely, and during September 2002 (55-75 days in milk) daily DMI and digestibility (DMD) were estimated for each cow by the n-alkane method. Grazing behaviour was observed visually. Daily milksolids yield (per cow and per 100 kg LW) were similar for NZ90 and OS90, which were higher than NZ70 (p<0.01). At the start of the season OS90 cows were heavier (p<0.05) than cows of the other two strains and NZ90 cows heavier (p<0.05) than NZ70 cows, however they were similar in BCS. During September OS90 cows were just slightly heavier than the other two strains (p=0.16), but with lower BCS (p<0.01). Between the start of the season and September, LW and BCS decreases for OS90 cows were significantly higher (p<0.05) than for cows in the other two strains. Slightly higher DMI (per cow and per 100 kg LW) were recorded for the NZ90{\textquoteright}s than for NZ70 and OS90. Grazing time, ruminating time or biting rate was similar across strains. These results suggest that the OS90 was not able to eat sufficient pasture and used more body energy reserves to produce similar MS yield as NZ90. }, issn = {1176-5283}, author = {Rossi JL and MacDonald KA and Thorrold B and Holmes CW and Matthew C and Hodgson J} } @conference {41512, title = {Modelling farm systems with once-a-day milking}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {237-240}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Our objectives were to investigate how a cow model, "Molly", deals with once-a-day milking and to use "Molly" in a Whole Farm Model to explore farm systems where once-a-day milking might produce results on a per hectare basis comparable to twice-a-day milking. We compared our model outputs to observed data from a Milking Frequency trial run by Dexcel at a research farm in Taranaki. Changing the rate constants for milk removal and degradation of the lactation hormone complex in "Molly" resulted in the model expressing the acute and chronic effects of once-a-day milking. The once-a-day cow model fed ad lib seasonal grass pasture showed a decrease in milksolids yield (kg/cow) of 31\% in Friesians compared to the observed 28\%. When we used .Molly. in the Whole Farm Model it showed that farm performance with once-a-day milking was 1135 kg milksolids/ha when a Friesian herd was stocked at 7\% higher and their lactation was extended by 14 days compared to a twice-a-day herd (1132 kg milksolids/ha). We conclude that farm performance with once-a-day milking is strongly dependent on selecting cows with higher lactational persistence under once-a-day milking and managing for extended lactations. }, issn = {1176-5283}, author = {Beukes PC and Thorrold BS and Wastney ME and Palliser CC and Clark DA} } @conference {41457, title = {Northern analysis of temporal and spatial variation in milk protein expression during early mammary involution in dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {5-7}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Understanding the mammary responses that occur at the cessation of milking whether natural, forced, or which occur at the end of the milking season and during the subsequent initiation of mammary involution (Holst et al., 1987; Hurley, 1989) has relevance in milk production traits such as milk yield, persistency and extended milking intervals and may suggest ways of improving milk production in later lactation (Stelwagen, 2001) (Vetharaniam et al., 2003). The proportions of secretory, support and milk storage components vary significantly between the alveolar (main milk synthesis), peripheral (a several cm thick layer of secretory tissue surrounding the main alveolar bed) and cisternal (main milk storage area adjoining the teats) compartments of the udder (Farr et al., 1996; Sordillo and Nickerson, 1988; Weber, 1977). In addition, variations in the local proportions of these components has also been observed in the main alveolar areas and dramatic variations of gene expression depending on the local mammary tissue composition have been observed (Molenaar et al., 1992). Ignorance of the effect on gene expression profiles resulting from sampling variations could lead to improper interpretation of experimental results and hence there is a need for more extensive spatial and temporal surveys to be done. }, issn = {1176-5283}, author = {Molenaar AJ and Farr VC and Oden KE and Wheeler TT and McMahon CD and Good LL and Stelwagen K and Singh K and Davis SR} } @conference {41482, title = {Pasture biotechnology - not as you know it}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {101-104}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {As part of an ongoing project to identify quantitative trait loci (QTL) for economically important traits in New Zealand dairy cows, a vaccine trial was conducted to measure the antibody response of 10 week old Friesian-Jersey crossbred calves to two antigenic compounds of a clostridial vaccine (Clostridium novyi B and Clostridium tetani toxoids). Blood samples were collected from 469 calves prior to vaccination at 10 weeks of age, prior to re-vaccination at 13 weeks of age and at 16 and 22 weeks of age. ELISA assays using conjugated rabbit anti-bovine IgG were conducted for both toxoids. Correlations and explanatory variables were calculated using correlation and general linear model (GLM) procedures in SAS. Antibody response to both toxins were relatively low after the first vaccination (week 13), but were boosted to high levels after revaccination (week 16). GLM analysis revealed a moderate sire effect contributing to the variability seen in the 13 week test against C. tetani (P=0.001) and the 16 week test against C. novyi (P=0.01). This variation in individual antibody response will be used in future research to identify genetic factors controlling the acquisition of immunity. }, issn = {1176-5283}, author = {Elborough KM and Hanley Z} } @conference {41489, title = {Phenotypic attributes of postpartum ovulation and other fertility measures in Friesian-Jersey crossbred cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {132-137}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Reproductive performance is an important factor contributing to on-farm efficiency and profitability. The purpose of this study was to define and quantify a set of fertility phenotypes for 352 Friesian-Jersey crossbred heifers, and determine key factors contributing to these indicators. Heats were observed and recorded prior to herd start of mating, and CIDRs were used to treat non-cycling heifers (51) once mating started. Progesterone samples were collected twice weekly, and luteal activity was identified where concentrations were >0.9 ng/ml for blood and >3.0 ng/ml for milk samples. Commencement of luteal activity was defined by either one elevated sample (CLA1) or two consecutive elevated samples (CLA2). For untreated heifers, the average intervals to CLA1 and CLA2 were 29.6 days (sd=14.3) and 34.1 days (sd=16.9) respectively. Other phenotypes were evaluated for conception and intervals to first heat, first service and successful service. Significant relationships were established between body condition score (BCS) at calving and the intervals to CLA. For every unit decline in BCS at calving there was an increase of 7.4 days to CLA1 and 8.8 days to CLA2. The evaluated fertility phenotypes, and their key contributing factors will be used in another study to identify related quantitative trait loci (QTL). }, issn = {1176-5283}, author = {Sanders KM and Bennett R and Spelman R} } @conference {41456, title = {Presidential Address 2003: The New Zealand Society of Animal Production - another 20 years}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {1-4}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Historically, the Presidential address falls into one of three general categories, 1) the President{\textquoteright}s area of interest in animal production, 2) the concerns and future direction of animal production or the Society or 3) a review of Society activities. Andrews (1963), Everitt (1973), Smith (1984) and Nicol (1992) have periodically reviewed the Society activities and it seems timely to do so again in 2003 {\textellipsis} }, issn = {1176-5283}, author = {Morrow C} } @conference {41478, title = {The process and technologies of gene discovery to application in dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {83-85}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {The heady days of biotechnology that were driven by the assumption that biotechnology would solve all biological problems with simple solutions, are over. The {\textquoteleft}biotech{\textquoteright} investment in the mid to late 1990{\textquoteright}s was driven predominantly by commercial and scientific enthusiasm, ignoring biological, commercial and regulatory realities. In the post-bubble environment, the dairy industry, including ViaLactia Biosciences and our research partner Livestock Improvement Corporation are undertaking a research program endeavouring to align the expectations of the market, the investors and the limits of technology. In general, the thrust has been to utilize existing or develop new biological resources and where they are required and not available, tools for discovery. Much of the on-going challenge is in defining the opportunity (desired phenotype), predicting technological developments, large scale investment in the public domain and matching the approach to the problem within time and budgetary constraints. Our approach will be presented with some examples of successes. }, issn = {1176-5283}, author = {Snell RG} } @conference {41468, title = {Red deer as a novel ruminant model for nutritional and genetic influences on maternal expression of foetal and neonatal growth}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {39-42}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {The red deer species (Cervus elaphus) is represented by morphologically disparate subspecies that freely crossbreed. All are highly seasonal breeders adapted to cold-temperate climates characterised by extreme annual oscillations in temperature and feed availability. Calves are born in summer following relatively long average gestation lengths of 234{\textendash}250 days (depending on subspecies), with >70\% of pregnancy mass acquired over spring/early summer. The ability of the smaller red deer hind (100 kg) to successfully gestate, birth and rear crossbred (e.g. wapiti x red deer) progeny of 40\% increased foetal and post-natal growth potential is quite remarkable, and raises numerous questions about mechanisms of maternal and foetal control of reproductive processes. Recent research on moderate variations in late gestational nutrition to red deer hinds gestating red deer foetuses has revealed an interesting phenomenon in which nutritional influences on foetal growth trajectory appears to influence gestation length to ensure optimisation of birth weight (and, hence, neonate survival). This is quite contrary to expectations for sheep and cattle, but may have parallels amongst other wild ruminant species. Interestingly, hinds gestating crossbred (wapiti x red deer) foetuses of greatly increased growth potential appear unable to adopt such compensatory mechanisms, with hind under-nutrition leading to reduced birth weight relative to ad-libitum fed controls. These observations hint at some interesting and useful future research on mechanisms of maternal and foetal growth control in red deer. }, issn = {1176-5283}, author = {Asher GW and Archer JA and Stevens DR} } @conference {41522, title = {Relation between sweating and wool yellowing in Merino and Romney sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {286-292}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Five adult Merino and five adult Romney ewes with 7 months growth of fleece were subjected to nine different environmental challenges in a climate controlled room on consecutive days where the temperature humidity index (THI) was varied from 74.2 to 91.3 for up to 7 h at each exposure. Secretions were collected from glands in the skin on the back, midside and belly regions of each sheep. The sheep were shorn 5 months later. There was a significantly curvilinear increase in total skin gland output and the rate of secretion of titratable alkalinity and potassium ions with increasing THI. Romney sheep had a higher secretion rate than Merino sheep with no significant site effect. The rate of secretion of titratable alkalinity and potassium ions by the skin glands were both strongly related to tristimulus (Y-Z) of the fleece at shearing (base yellow) (R2 = 0.93, 0.92) and after incubation of the wool sample at 40{\textdegree}C and 100\%RH for 6 d (challenge yellow) (R2 = 0.96, 0.95). These data indicate a particularly strong relationship between the rate of secretion of titratable alkalinity and potassium ions by the skin glands and the later propensity of the fleece to develop a yellow discolouration. }, issn = {1176-5283}, author = {Sumner RMW and Ashby MG and Craven AJ} } @conference {41493, title = {Relationship between intramammary infection and teat characteristics}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {147-149}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {The relationship between teat characteristics and intramammary infection (IMI) was investigated in 111 cows. These cows were scored visually on teat shape, teat-end shape and teat pigmentation. Subsequently, foremilk quarter samples were collected weekly for 14 weeks from calving to assess bacterial presence and somatic cell count (SCC). Teat shape and teat-end shape were combined and termed teat type. The distribution of teat type was cylindrical- round (34\%), funnel-round (21\%), cylindrical-flat (16\%) and bottle-round (9\%). Approximately 44\% of teats were fully pigmented (black/brown) while 25\% of teats were pigmented over less than 20\% of the surface area. The frequency of quarters that never became infected during the trial period was 78.4\% and the mean SCC was 69,000 cells mL-1. Among the infected quarters, the most frequently isolated pathogens were Corynebacterium bovis (45\%), coagulase negative staphylococci (CNS) (43\%) and Streptococcus uberis (6\%). Analyses showed no associations between teat characteristics and quarters not becoming infected, or between teat characteristics and bacterial pathogens in infected quarters. }, issn = {1176-5283}, author = {Lopez-Benavides MG and Williamson JH and Walters JB and Hickford JGH} } @conference {41513, title = {Remote automatic selection of cows for milking in a pasture-based automatic milking system}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {241-245}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {New Zealand pastoral dairy farming presents unique challenges for combining automatic milking systems (AMS), including long walking distances, large herds, year round pasturing and a predominately fresh pasture diet. This paper describes a system designed to minimise walking, maximise the efficiency of AMS utilisation and enable control of individual cow milking frequency by remotely selecting cows for milking up to 400 m from the dairy. Cows report to a selection unit (SU) located in the centre of a block of pasture and linked via raceways to the AMS. Entry is via one-way gates and exit via a computer controlled drafting gate, which directs the cow either to the dairy or the paddock depending on time since last milking. A communication cable connects the SU to the AMS server in the dairy. Cows wear an electronic identification device. Water and pasture access act as incentives for cows to enter the SU. Cows readily learned to use the SU and were observed visiting the unit at every hour over 24 hours. Twenty-seven cows were assigned to either a 6h or 12h minimum milking interval (MMI). On average, cows visited the SU 4.5 and 5.5 times/d for the 6h MMI and 12h MMI groups, respectively, and achieved a milking frequency of 1.9 and 1.4 milkings/d, respectively. Results showed that milking frequency can be controlled via a system for remotely selecting cows for milking and that access to fresh pasture is a strong factor in motivating cow traffic through the SU. }, issn = {1176-5283}, author = {Jago J and Bright K and Copeman P and Davis K and Jackson A and Ohnstad I and Wieliczko R and Woolford M} } @conference {41525, title = {Resilience to nematode parasite challenge in industry and AgResearch selection flocks}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {300-303}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {A large-scale industry project on the resilience of lambs to nematode parasite challenge was undertaken in 2001/02 and 2002/03, to evaluate the feasibility of recording standardised age at first drench (StAge) and postweaning weight gain under nematode challenge, and to estimate genetic differences among flocks. The project involved 15 Romney flocks from two ram breeding groups, with some flocks having been part of an earlier AgResearch study of the genetics of resilience traits. This provided the opportunity to assess any correlated changes in resilience over time (where direct selection over that time period in the industry flocks had been applied to productivity traits, but not to resilience), and to compare the industry performance with AgResearch Resilient-selected and Control lines. The overall estimates of heritability for StAge and weight gain (2 time periods: Gain1 and Gain2) were 0.14 {\textpm} 0.014, 0.30 {\textpm} 0.015 and 0.15 {\textpm} 0.007, respectively. Genetic correlations between StAge and either Gain1 or Gain2 were 0.30 {\textpm} 0.06 and 0.41 {\textpm} 0.06, respectively. Genetic differences for all traits between the two industry groups were small and not significant. The genetic differences of the current industry-group means (all 15 flocks) above the AgResearch Control line were small (0.8 days, 0.5 kg and 0.9 kg, respectively). In comparison, the genetic differences of the AgResearch Resilient-selected line over the Control line after eight years of selection were 19 days, 0.7 kg and 1.4 kg (11, 8.3 and 9.6\% of the industry means). The results confirm that while selection for increased resilience is feasible (although very time-consuming) under commercial conditions, a ram breeder would need to consider an index approach which combined production and resilience traits, to make best use of his animal resources. }, issn = {1176-5283}, author = {Morris CA and Amyes NC and Bisset SA and Mackay AD} } @conference {41462, title = {Sheep nutrition, fetal growth and human health}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {17-18}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {In 2003 the Centre of Research Excellence (CoRE) for Growth and Development was formed. The purpose is to conduct research into growth and development, focussing particularly on the issues of pre {\~n} and post natal growth and its implications for human health. The medical challenges for the developed world are those associated with the nutritional environment, obesity and the associated illnesses of diabetes and cardio {\~n} vascular disease. There is evidence linking the propensity for these diseases to the nutritional status of the fetus in the first trimester of pregnancy and the interaction of this status with nutrition in the immediate post {\~n} natal period. In this respect the problem differs from the issues considered by animal production. Here the last trimester of pregnancy has received the most attention, and few domestic animals live long enough for cardio {\~n} vascular problems to arise. Nevertheless the skills and methods of investigation developed by animal scientists can be applied to these new problems. }, issn = {1176-5283}, author = {Harding JE and Bloomfield FH and Oliver MH} } @conference {41473, title = {A split night photoperiod does not mimic effects of a long-day photoperiod on growth in weaner red deer stags}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {63-66}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {In sheep, the effects of a long day photoperiod can be mimicked by providing a {\textquoteleft}split night{\textquoteright} light stimulus during the dark phase of a short-day photoperiod. This study tested the hypothesis that a similar response to a split night photoperiod occurs in deer. From 6 May until 3 September 2003, three groups of weaner red deer stags (n = 10) were subjected to: natural daily photoperiods (short days, experiencing the normal seasonal pattern of daylight), a long day photoperiod (16L:8D, where L = h of light, D = h of darkness) or natural daily photoperiods with a period of 1 h of light (circa 370 lux) during the dark phase (split night). For the first 3 months, liveweight gain was similar in all groups (approx. 140 g/day). However, growth of long-day exposed animals began to exceed that of the other treatments so that after 6 August their mean liveweight was significantly (P < 0.01) greater than that of the other groups. From 26 June to 3 September mean liveweight gain was, 324 {\textpm} 28.3, 209 {\textpm} 23.9 and 186 {\textpm} 20.6 g/day for long day, split night and short day photoperiod groups, respectively. The long day group had the highest voluntary feed intake and appeared to initiate antler pedicle growth and testicular enlargement earlier than the other groups. Plasma prolactin concentration was elevated (P < 0.01) by the long day treatment (mean for long day group at 9 July = 33.4 {\textpm} 4.09 versus means of 6.9 {\textpm} 3.75 and 2.9 {\textpm} 0.99, ng/ml for split night and short day groups, respectively). These results show no stimulatory effect of the split night photoperiod on growth of red deer. It is concluded that some of the photoperiodic signals that can cause physiological changes in sheep are not effective in deer and, hence, there are differences in the underlying mechanisms of photoperiodism between these two species. }, issn = {1176-5283}, author = {Crowley V and Barrell GK and Keeley MJ} } @conference {41506, title = {A survey of goat meat acceptability in Japan}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {208-211}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {A questionnaire survey was designed to gauge consumer interest in goat meat. The questionnaire was responded to by 98 households living in or near Tokyo. The main results of the survey are as follows. 1) Impression of goat meat; 61\% of the respondents indicated that goat meat was {\textquotedblleft}not common in their home{\textquotedblright}. 2) Consumer experience; only 16\% of the respondents had experience of eating goat meat and they felt goat meat is {\textquotedblleft}smelly{\textquotedblright} (50\%), {\textquotedblleft}tender{\textquotedblright} (38\%) and {\textquotedblleft}delicious{\textquotedblright} (31\%). 3) The two main reasons why consumers have not eaten goat meat were {\textquotedblleft}lack of purchasing opportunity{\textquotedblright} (78\%) and {\textquotedblleft}don{\textquoteright}t feel like eating it{\textquotedblright} (18\%). 4) Options to promote goat meat consumption; 52\% of respondents who have not eaten goat meat were prepared to purchase if it was available in the supermarket at a reasonable price and if recipes were added with the meat package. 5) Reasons for people not purchasing goat meat included {\textquotedblleft}dislike of new meat{\textquotedblright} and {\textquotedblleft}pity for the goat{\textquotedblright}. These results show that goat meat can be promoted to the Japanese households as {\textquotedblleft}a new product{\textquotedblright} if the price is reasonable and recipes are added to the package. However, a considerable number of market strategies need to be implemented to achieve the acceptance of goat meat by Japanese consumers. }, issn = {1176-5283}, author = {Ozawa T and Lopez-Villalobos N and Blair HT} } @conference {41501, title = {Understanding shepherding within lambing, and organic farming systems through acknowledging cultural, community and individual influences}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {183-187}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {The way we farm depends on the species farmed, the environment, and on our beliefs, prejudices and expectations. A model was developed to consider cultural influences, community ethics, and individual goals to help understand shepherding and organic farming. Assisting sheep at lambing is reinforced by cultural expectations of what shepherds should do. Different management strategies are used depending on the sheep, their environment, and the costs and practicalities of supervision. Finally, the weight given to different factors may depend on the motivation of individuals in deciding to "live with the flock" or find better ways of managing lambing. Reflecting the different goals of agriculture, individuals were motivated to convert to organic farming by economic returns, the environment, chemical use, food safety and quality, animal health and welfare, and a desire to maintain rural communities. The safety of chemicals, food quality, and the environment are central to understanding the value of organics to the community. Finally, organic farming is informed by stories of {\textquotedblleft}being at one with nature{\textquotedblright} An understanding of the different beliefs that inform us of the way farming is, or should be, may result in a greater shared understanding of complex issues, and more equitable farming practices. }, issn = {1176-5283}, author = {Fisher MW and Small BH and Mackay AD and Kenny GJ and Jerebine BC and Parminter TG} } @conference {41486, title = {Use of breeding values for live weight to calculate individual live weight targets for dairy heifers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {118-121}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Replacement heifers need to reach specific target live weights (LW) to ensure they calve as two year olds, and subsequently achieve high milk yields and good fertility. Currently, different LW targets are recommended for heifers based on their expected mature LW according to appearance or breed. However, the mature LW is difficult to estimate without knowledge of the animals. genetic potential for LW. The objective of this paper is to develop and validate a growth model which uses estimated breeding values for LW (EBV LW) of individual heifers of any breed to calculate target LW from birth to maturity. Predicted live weights are presented for a range of four EBV LW, from {\textendash}40 to 100 kg. These values were very similar to other published target values. Data from the Dexcel Holstein Friesian Strain Trial was used to validate the model with respect to LW and age at puberty. For LW at puberty the predicted values were significantly correlated (P<0.05), but were marginally higher (3-5\%) than the actual values. A report can be formulated to enable farmers to identify individual heifers which are below (or above) their target LW at any date }, issn = {1176-5283}, author = {Bryant JR and Holmes CW and Lopez-Villalobos N and McNaughton LR and Brookes IM and Verkerk GA and Pryce JE} } @conference {41458, title = {The use of cDNA microarrays to investigate changes in gene expression in the involuting bovine mammary gland}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {8-10}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {The molecular mechanisms and pathways involved in involution of the udder and which coordinate and regulate the processes of cell death and proliferation after weaning/cessation of milking in ruminants, are poorly understood. The aim of this study was to use cDNA microarray analysis to identify genes and pathways involved in involution of the bovine mammary gland. Ultimately, because this process underpins lactation traits such as persistency and mammary responses to milking frequency (Stelwagen, 2001; Vetharaniam et al., 2003), this information may allow the development of novel strategies for improving milk production especially in the later stages of lactation. Involution of the bovine mammary gland was induced by abrupt termination of milking in 48 non-pregnant Friesian dairy cows at mid-lactation (average days in milk, 92 {\textpm} 3) {\textellipsis} }, issn = {1176-5283}, author = {Singh K and Molenaar AJ and Stelwagen K and Farr VC and Good L and Swanson K and Oden K and Wheeler T and McMahon C and Henderson H and Wilson T and Hyndman D and Baird D and McCulloch A and Davis SR} } @conference {41460, title = {The use of microarrays to investigate gene regulation in the bovine mammary gland during Streptococcus uberis mastitis}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {14-16}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Bovine mastitis is one of the most costly dairy-based diseases worldwide with an estimated $60 M loss to New Zealand per season. Mastitis infections are a result of bacterial or fungal pathogens becoming established in the udder, and are detected by the increase of somatic cells in the mammary gland, bacteriology data and physical signs of infection. In New Zealand, mastitis is usually a result of a gram-positive bacterial infection (Brookbanks, 1966). Of these bacteria, Streptococcus uberis is emerging as one of the most prevalent causative organism of mastitis in New Zealand (McDougall, 2002). It resides naturally in the environment making prevention of the disease difficult. Currently the main means of controlling the disease is through administering antibiotics following identification of infection. The mammary gland is protected from invasion by the activation of non-specific (innate) and specific defence mechanisms. The innate immune response is the predominant defence during the early stages of infection and is induced rapidly at the site of infection (Sordillo et al., 1997). Although the local mammary innate immune response has been widely investigated, studies have focussed on known antibacterial compounds and little is known about the novel compounds in bovine milk and how these contribute to the defence system of the mammary gland. The mechanism by which the mammary gland innate immune system is active against S. uberis is poorly understood. By developing an understanding into the way S. uberis induces an immune response in the mammary gland and the effect of infection on mammary gland metabolism we may identify components which can be utilised to either reduce the symptoms of/or prevent or cure S. uberis mastitis. }, issn = {1176-5283}, author = {Swanson KM and Henderson HV and Farr VC and Davis SR and Oden K and Stelwagen K and Molenaar A and Singh K and Prosser CG} } @conference {41479, title = {What the bovine genome project means to New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {86-91}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {The sequencing of the bovine genome commenced in December 2003 and sequencing is planned to achieve a seven-fold coverage by November 2005. This along with previous physical mapping efforts will allow a high quality genomic assembly to be produced. The sequencing is being undertaken by Baylor College of Medicine in Texas. Separately, the Michael Smith Genome Science Centre in Vancouver will sequence 10,000 full length non-redundant bovine mRNAs. The assembled genome will be annotated in collaboration with the Ensembl project at the Sanger Institute, UK, and will be publicly available on genome browsers such as NCBI, Ensembl and UCSC. In the interim the raw sequence information is being made available at NCBI within days of being generated. As well as providing DNA sequence, the program will identify more than 50,000 microsatellites and one to two million SNPs. The availability of this information will transform and accelerate ruminant genomics research. Similar genome sequencing efforts in human and laboratory species have greatly increased the rate of gene variant discovery underlying quantitative trait loci. It will also aid our understanding of gene expression control. New Zealand stands to benefit directly from this work, because of its strong reliance on grazing livestock for export income and its internationally competitive beef and dairy industries. The project is funded by an international consortium involving CSIRO Australia, Genome Canada, New Zealand, National Human Genome Research Institute of the U.S. national Institutes of Health (NHGRI), U.S. Department of Agriculture (USDA), the State of Texas, The Kleberg Foundation, U.S. Beef Council, and Texas and South Dakota Beef Councils. Significantly, the National Institutes of Health have strongly supported the project as a consequence of its human health implications. This project benefited greatly from a previous international genomic collaboration to physically map the bovine genome, and it provides an excellent example of benefits obtained from international research consortia co-investing in public domain infrastructural projects. }, issn = {1176-5283}, author = {McEwan JC and Crawford AM} } @conference {41520, title = {Zinc dipping can help reduce wool yellowing}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {277-281}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {On one farm dipping sheep once or twice with zinc sulphate had no effect on the yellowness of wool at shearing. When data from this farm were combined with data reported earlier, the reduction in yellowness was linearly related to the yellowness of the control group (P = 0.091, 0.032 for dipped once or twice, respectively). On another farm, groups of 20 rising two-tooth New Zealand Halfbred ewes were treated in February by either dipping with zinc sulphate solution (2.45 g Zn/l) or dosing with a zinc bolus. Both treatments reduced the yellowness of belly wool at crutching (May) (Y-Z = 4.31, 2.13 and 1.87 for control, bolus and dipped sheep, respectively, P<0.01), but had no effect on the yellowness of the flank wool (Y-Z = -0.16, -0.27, -0.06). Zinc concentrations in clean wool (initial concentration = 78.5 mg/kg) were increased in all three groups at crutching but the differences were significant for the dipped group only (zinc concentrations = 160, 211, 340 mg/kg for control, bolus and dip, respectively, P<0.001). Thus, in some cases, increasing the concentrations of zinc in wool can reduce yellow discolorations at shearing. The effect will be greatest where wool from untreated sheep is yellowest. This could prove to be a useful method to improve wool quality on some farms. }, issn = {1176-5283}, author = {Reid TC and Urquhart RA} } @conference {41418, title = {Achieving 4\% productivity: Implications from a longitudinal study of farmer learning in dairy farming}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {116-119}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {The New Zealand dairy industry needs to achieve 3 to 4\% pa gains in productivity. Accomplishing this on-farm will require continuous innovation by farmers. Innovation may result from the refinement of existing practices, or the introduction of new practices or technologies. Farmer learning will be pivotal to the rate of innovation. However, despite its importance, relatively little is known about farmer learning. We investigated the tactical feed management processes used by two high-performing dairy farmers over summer-autumn for three years, using a multiple-case study design. Learning undertaken by the farmers could be classified within three broad domains (the production and management systems, and the environment), but normally involved the interactions between at least two of these. Two stimuli initiated learning: the occurrence of extreme conditions or the introduction of a new management practice. Different learning processes were identified with respect to these. This study provides a framework for extension agents to identify the {\textquotedblleft}knowledge gaps{\textquotedblright} farmers need to close in order to improve productivity. It also assists developers of a new technology, since farmers want to know how the new technology impacts on their production systems, responds under a range of conditions, and is best incorporated into their management.}, issn = {1176-5283}, author = {Gray DI and Parker WJ and Kemp EA} } @conference {41439, title = {The Alliance Central Progeny Test: Preliminary results and future directions}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {197-200}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {The Alliance Central Progeny Test (CPT) was established in 2001 with the aims of improving the carcass dollar value of sires under the Alliance grading system and establishing links among ram breeders so Alliance can identify the best rams for their clients. In the 2002/2003 season 22 terminal sires from nine different breeds were evaluated. Each ram was mated to 30 ewes at the AgResearch Woodlands research farm. Progeny numbers for each ram ranged from 13-46. Initial early results showed that breeding values for weaning weight were well spread among sires (range over 2.5 kg) indicating there were genetic differences among sires used. Lambs were slaughtered in four slaughter groups between December 16th , 2002 and March 11th , 2003. Analyses from the full data set will be available from May 2003. The next cycle of the Alliance CPT begins with mating in April, 2003, with an emphasis on dual-purpose sires.}, issn = {1176-5283}, author = {Campbell AW and Knowler K and Behrent M and Jopson NB and Cruickshank G and McEwan JC and Wilson T} } @conference {41452, title = {Approaches in developing a successful trans-cervical AI programme for farmed deer}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {258-261}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {Trans-cervical artificial insemination (AI) in farmed deer has emerged as a highly successful reproductive tool that can rapidly increase rates of genetic gain in farmed deer. Conception rates in excess of 70\% are confidently achieved if all aspects of a simple programming prescription are followed. Hind nutrition, attention to hygiene and reducing individual animal and herd stress levels appear to be key factors, over and above that of semen quality and insemination skills. Many factors cumulatively affect success or failure within the typical eight week breeding season. Combinations of care and attention to detail are essential. This paper considers the interplay of these factors in advising choices made that underpin a successful trans-cervical AI programme based on commercial experiences. }, issn = {1176-5283}, author = {Rhodes L and Pearse AJT and Asher GW} } @conference {41429, title = {Assessment of fleece cover in crosses between Coopworth, Dorper, Damara, New Zealand Wiltshire, Poll Dorset and Suffolk sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {160-163}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {Fleece cover was assessed over 10 body regions for nine pure and crossbred combinations of progeny from longwool, short-wool and hair breeds of sheep. Assessments were made between docking and hogget shearing. Visually assessed fleece-cover scores varied by less than 0.35 units within day (P = 0.757) and 0.21 units between days (P = 0.120). Differences of 0.2 units between assessors (P<0.05) were tolerable in a scoring system utilising whole measurement units. The average fleece cover of Wiltshire and Dorper x Wiltshire lambs was 1.14 and 0.92 units less than Coopworth lambs at weaning (P<0.01) but no different at hogget shearing (P = 0.17). The temporary reduction in fleece cover at weaning was attributed to shedding of fibres from the fleece. All breed combinations studied produced between 29 and 67\% less fleece than Coopworth hoggets (P<0.001). However, without the ability to synchronously shed their fleece, first generation crossbred progeny required shearing as hoggets. }, issn = {1176-5283}, author = {Merrick NC} } @conference {41403, title = {Beef traceability systems in Japan - how should New Zealand prepare?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {49-52}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {Interviews were held with National Federation of Agricultural Cooperative Association (NFACA), Ministry of Agriculture, Forestry and Fisheries (MAFF) and New Zealand Meat Board staff to describe current beef traceability systems operating in Japan following the BSE incident there in 2001. Some suggested actions for the New Zealand beef industry to become more competitive against domestically produced beef are described from a traceability perspective. It is concluded that there is no sustainable, complete (from farm to consumer) beef traceability systems being operated in Japan, not only by domestic producers or retailers, but also by overseas companies. Domestic traceability systems are either facing financial problems (NFACA system) or functional problems (MAFF system). This means that if New Zealand adopts a farm to consumer traceability system in the Japanese market, it will be the pioneer and will be recognised, as "clean and green", not only by nuance, but also in practice by the Japanese consumer. The main problem for New Zealand adopting such a traceability system in the Japanese market is balancing anticipated expenses versus expected financial return to the New Zealand beef producer. }, issn = {1176-5283}, author = {Ozawa T and Lopez-Villalobos N and Blair HT} } @conference {41441, title = {The benefits of across-flock analysis}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {204-208}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {Recent and current developments by Sheep Improvement Ltd (SIL) to provide animal evaluations for a wide variety of flocks using Best Linear Unbiased Prediction (BLUP) methods have encouraged breeders to compare animals bred in different breeding flocks. The data requirements and analytical models needed for BLUP to handle this task are discussed with major emphasis on sire-referencing as a method for achieving adequate genetic linkages among flocks by which animals bred in different flocks may be compared. Despite the high ability of BLUP to accommodate this task and the benefits perceived by many breeders, few specific studies of potential benefits for particular breeding schemes have been reported. In general terms, the impact of across-flock evaluations on annual rates of genetic gain varies for different traits, mating strategies, flock and industry structures. They may not always be cost effective in comparison to within-flock performance selection, especially for larger flocks and when the costs of implementing the flock structures needed to make them accurate and effective in evaluating and disseminating genetic merit are taken into account. }, issn = {1176-5283}, author = {Clarke JN} } @conference {41432, title = {Calculating animal performance from limited liveweight measurements of the population}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {173-175}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {We consider the problem of estimating the distribution of carcass weights in a flock of animals from estimates made on a truncated sample. This arises when a farmer chooses the heaviest lambs for slaughter and then measurements are made by the meat processor. This enables a farmer to answer two questions: what proportion of the animals remaining exceed a nominated carcass weight, and/or what carcass weight is exceeded by a nominated proportion of the population? Estimates of these statistics and their uncertainties are derived and are exact if the animal weights are normally distributed. These calculations can be the basis of decisions about future feeding and drafting strategies, important for farmers producing animals on contracts for future delivery. An example is given based on 1000 lambs using a cut-off weight of 15.5 kg with mean of this upper group of 16 kg. Using a realistic estimate of a standard deviation (of the weighing scales) of 0.3 kg, this gives an estimated mean of 14.6{\textpm} 0.04 kg, with a standard deviation of 0.94{\textpm}0.044 kg, and that 75\% of the lambs in the population exceed 13.9{\textpm}0.07 kg. The proportion of lambs that exceed 14.5 kg is then between 51.3\% and 55.7\%. }, issn = {1176-5283}, author = {Wake GC and Pleasants AB} } @conference {41430, title = {Can dipping sheep with zinc sulphate reduce wool yellowing?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {164-168}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {On each of four farms, groups of ewes were either not dipped, dipped once or dipped twice with zinc sulphate solution (20 g/l). Base and challenge yellowness were determined on core wool samples collected at shearing. Dipping with zinc sulphate increased the zinc concentration of wool at shearing from 154 (range 77-321) to 421 (range 116- 1140) (dipped once) or 806 (range 143-1920) mg/kg (dipped twice). Zinc sulphate dipping had no effect on the base yellowness of wool on three farms, but significantly reduced wool base yellowness on the fourth farm (Tristimulus (Y- Z) = 9.0 vs. 7.8 vs. 8.5 for control, dipped once and dipped twice, respectively) (P<0.01). In the laboratory, wool samples from all farms were significantly less yellow after challenge when sprayed before challenge with zinc sulphate solution than when sprayed with water (9.9 vs. 10.9; 7.1 vs. 10.0; 8.3 vs. 10.6; 11.3 vs. 13.1) (P<0.001). There was a significant relationship (R2 = 83.4\%, P<0.001) between the changes in zinc concentration resulting from zinc dipping and the changes in yellowness of the wool with challenge. These results indicate that dipping sheep with zinc may reduce discoloration of greasy wool at shearing under environmental conditions in which yellowing is maximised.}, issn = {1176-5283}, author = {Reid TC and Urquhart RA} } @conference {41417, title = {Comparison of multivariate statistical methods for the prediction of reproductive performance of Holstein Friesian cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {112-115}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {The objectives of this study were to predict success or failure at mating (1/0) using information on 168 first lactation dairy cows from the Dexcel Strain Trial. The farmlets were established by allocating heifers from three genetic strains to eleven groups. The groups were managed under a range of feeding systems, ranging from moderate to generous allowances. Measurements were taken on milk, fat and protein yields, liveweight and condition score and variables derived from these used as predictors of success at mating in a series of models. Reproductive measures used for analysis were cows in calf at 42, 49 and 56 days after the planned start of mating. Three statistical methods were used to determine suitable predictive models of success at mating: logistic regression, discriminant analysis and partition analysis. Partition analysis was the best method of prediction. Kappa values, measuring the degree of agreement between observations and predictions ranged between 0.32 and 0.38 for discriminant analysis, 0.41 and 0.44 for logistic regression and 0.70 and 0.74 for partition analysis. The partition analysis produced a set of rules for predicting likely success at mating. Important rules were CS > 4.75 in month three of lactation and calving before week four after the start of calving for the herd. }, issn = {1176-5283}, author = {Harris BL and Pryce JE and Verkerk G} } @conference {41397, title = {Conjugated linoleic and trans-vaccenic acids in grass-fed beef and lamb}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {21-24}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {Cis-9 trans-11 conjugated linoleic acid (CLA) found in ruminant milk and meat has several human health benefits of which the anti-cancer effect is the most prominent. Trans-vaccenic acid (TVA) is a precursor of CLA and can be considered as another dietary source of CLA. This paper uses data from three published papers to compare the CLA and TVA concentrations in the longissimus lumborum muscle (LL) from cattle and lambs, to determine the within- group variation, and to identify factors influencing this variation. The paper discusses the contribution lean beef and lamb can make to the estimated human daily required intake (DRI) for CLA. The CLA and TVA content was measured in the LL from two groups of cattle (n = 15 and n = 100) and two groups of lambs (n = 30 and n = 12). CLA and TVA concentrations in the total fatty acids (TFA) was higher (P<0.001) in lamb than in beef. The coefficients of variation within each group of animals ranged from 23-41\% for CLA and 25-68\% for TVA, indicating a large variation in the concentration of these fatty acids among animals. A number of factors contributed to these differences but the largest difference was found in lambs, where there was a 41\% higher (P<0.01) CLA concentration in the TFA from lambs born to ewes with high CLA concentrations than from lambs born to ewes with low CLA concentrations in their milk fat. A 100g portion of lamb containing 2-4\% lipid could contribute 2-5\% of the estimated 750mg DRI of CLA for humans. However, if dietary TVA was assumed to be equivalent to CLA, then lamb could contribute 13-15\% of the DRI. We conclude that lamb can provide a significant proportion of the DRI for CLA for humans and there is scope for farmers to further increasing the CLA and TVA content of beef and lamb.}, issn = {1176-5283}, author = {Knight TW and Morris CA and Purchas RW and Agnew M} } @conference {41455, title = {Designing pastures for modern deer farming systems}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {274-279}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {Following on from definitive measurements on deer preferences to pasture species by Hunt \& Hay in the late 1980{\textquoteright}s, this paper provides some practical guidelines for how forage programmes can be set up in NZ deer farming systems. These programmes take into account the highly selective nature of NZ red deer, their strong preference for herbs and legumes well ahead of grasses. Three groups of pastures are put forward for use in integrated breeding and finishing deer systems. Group I are general purpose pastures, based on perennial grass species but include desirable herb and legume species. Within this group key selection criteria such as ryegrass heading date, endophyte type andploidy level are discussed. Group II pastures are built around the high performance characteristics of hybrid ryegrases including high soluble carbohydrate levels and cool-season yield, while still incorporating important legume and herb contributions. This group is considered strategically important in meeting the rapid growth demand of weaners in both the autumn and early-spring. Group III are specialist pastures based soley on herb and legume species. Collectively they are characterized by high animal VFI and performance, strong dietary preference by deer and winter dormancy. Their use for enhanced hind lactation and fawn growth rates, and mid-spring weaner growth is discussed. Pasture groups replacement rates, proportions within a whole farm system and some key establishment and management considerations are also addressed. }, issn = {1176-5283}, author = {Moloney S} } @conference {41426, title = {Development of a technique to evaluate the role of elevated maternal thyroid hormone concentrations in the birthweight response to mid-pregnancy shearing.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {149-151}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {Several studies have shown that lambs born to mid-pregnancy shorn ewes are heavier at birth than those born to unshorn ewes (Morris et al. 2000, Kenyon et al. 2002a,b) but, the mechanism responsible has not been identified. Morris et al. (2000) observed elevated maternal triiodothyronine (T3) concentrations over a 20-day period after shearing at mid-pregnancy in both single- and twin-bearing ewes and subsequently found an increased birthweight in the singletons. Symonds et al. (1989) also reported maternal T3 and T4 concentrations to be higher in pregnancy-shorn housed ewes although, an altered birthweight was not reported. }, issn = {1176-5283}, author = {Kenyon PR and Parkinson TJ and Revell DK and Morris ST and McCutcheon SN} } @conference {41420, title = {Diet and genotype affect feeding behaviour of Holstein-Friesian dairy cows during late lactation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {124-127}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {Ingestive behaviour of New Zealand (NZ) and overseas (OS) Holstein-Friesian (HF) dairy cows grazing pasture only or fed a total mixed ration (TMR) was observed in late lactation. Data from visual observations every 10 minutes over a 48-h period were used to evaluate differences in time spent feeding, ruminating, standing and lying. OS HF and cows fed TMR had greater dry matter intakes (DMI) than their respective comparisons. Cows grazing pasture spent more time feeding, less time ruminating, less time standing and the same time lying, compared to cows fed TMR. OS HF spent less time feeding, the same time ruminating, the same time standing, and more time lying compared to NZ HF. When expressed in terms of DMI, OS HF took less time to consume a kg of DM, and spent less time ruminating each kg of DM compared to NZ HF, irrespective of diet. A genotype x diet interaction was observed for time spent standing, with NZ HF spending more time standing when fed TMR, but standing for a similar time as OS HF when grazing. These results suggest feeding and grazing behaviour differences between HF cows of differing genotype, but similar breeding worth. }, issn = {1176-5283}, author = {Thorne PL and Jago JG and Kolver ES and Roche JR} } @conference {41412, title = {Diet and genotype affect milk lactoferrin concentrations in late lactation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {87-90}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {Although lactoferrin (Lf) is a valued milk protein, little information is available on factors that affect its concentration in milk. Milk samples were collected during late lactation to determine if diet or cow genotype affected the concentration and yield of Lf in bovine milk. Holstein-Friesian (HF) cows (n=52) of either overseas (OS) or New Zealand (NZ) ancestry were fed either an all-pasture diet or a total mixed ration (TMR). Milk samples were collected from each cow during an AM milking in early March and late April. NZHF had a higher (P<0.05) Lf concentration than OSHF even though they produced less (P<0.05) milk. Genotype did not affect Lf yield, somatic cell count or the proportion of bacteriologically negative quarters. The Lf concentration in the milk of cows fed TMR was higher (P<0.05) than cows grazing pasture in April but not in March. Cows fed TMR also produced more (P<0.05) milk and a greater (P<0.001) yield of Lf than cows grazing pasture. Diet did not affect SCC, however only cows fed TMR had any bacteriologically positive quarters. A positive within-cow correlation (P<0.001) was found between Lf and SCC. The effect of diet on the concentration of Lf in milk requires further investigation. The genotype results suggest that NZHF have higher concentrations of Lf in milk than OSHF. Naturally high concentrations allow improved extraction efficiencies of Lf during processing. }, issn = {1176-5283}, author = {Turner S-A and Williamson JH and Thomson NA and Roche JR and Kolver ES} } @conference {41416, title = {Diurnal variation in blood plasma metabolites and insulin of lactating dairy cows grazing pasture and supplemented with a high-lipid supplement either once or twice a day}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {107-111}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {The experiment determined the diurnal variation of a blood plasma hormone and three metabolites (insulin, glucose, NEFA and triglyceride) and how these varied with different frequencies of supplementary feeding. Twenty-four cows in early lactation (DIM 81 {\textpm} 20) were divided randomly into three treatments; grazed pasture only and pasture supplemented with 2 kg/cow/day of ruminally protected oilseed supplement (metabolisable energy 19 MJ/kg DM) either once a day after morning milking or twice a day after morning and afternoon milking. On day 12 of the experiment, 12 cows (4 cows/treatment) were jugular catheterised and commencing at 1600 h, blood sampled at 2-hourly intervals for 24 h. This protocol was repeated for the remaining 12 cows on day 13 Concentrations of the selected blood plasma hormone and metabolites varied diurnally (P<0.001). The difference between the average peak and nadir concentrations over the 24 hours were 54\%, 66\%, 224\% and 63\% for plasma insulin, glucose, NEFA and triglyceride respectively. Feeding the lipid supplement increased blood plasma NEFA (P<0.01), and triglycerides (P<0.001) but had no effect on insulin, or glucose concentrations. Frequency of supplementary feeding influenced (P<0.05) the diurnal variation of NEFA but not, insulin, glucose, or triglyceride. Concentrations of NEFA, glucose, and triglyceride were variable between 0600 h and 1000 h and stabilised between 1600 h to 2000 h. Plasma insulin concentrations were low and stable between 0400 h to 0800 h. Consideration of diurnal variation and the stability of the blood plasma components measured led to the recommendation that the best time to blood sample for insulin is between 0400 - 0800 h and for glucose, NEFA, and triglyceride, between 1600 2000h. }, issn = {1176-5283}, author = {Thomson NA and Singh K and Kay JK} } @conference {41419, title = {Dominance effects on the time budget and milking behaviour of cows managed on pasture and milked in an automated milking system}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {120-123}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {The influence of social hierarchy on the behaviour of a herd of 41 cows milked in an automated milking system (AMS) was studied under conditions of free or no access to water at pasture. In phase 1 (P1) water was available within a central collection area (CCA) in the centre of the farm from which return to pasture was via the AMS. In phase 2 (P2), water was available at pasture in addition to the CCA. The time budget for activity (grazing, standing, lying or walking) and location (paddock, CCA entrance race, exit race or waiting yard) was determined over 2x24h in each of P1 \& P2. Dominance values (DV) were calculated and cows classified as high, middle or low ranking. In P1 \& P2, DV was positively related to the number of milking visits to the AMS. In P1, 83.4\% of all drinking occurred in the CCA compared with 14.2\% in P2. Social rank had no effect on time budget in P1, however, in P2, DV influenced waiting times with lower ranking cows spending a greater proportion of time waiting before entering the AMS. The results show that social rank affects the number of visits to the AMS and yard waiting times but has little effect on the activity time budget of cows milked in a AMS. }, issn = {1176-5283}, author = {Jago J and Jackson A and Woolford M} } @conference {41408, title = {Effect of genetic merit on the estimated partitioning of energy towards milk production or liveweight gain by Jersey cows grazing on pasture}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {69-72}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {Data from the 1999/2000 season of the Stratford demonstration farm stocking rate trial was used to estimate metabolisable energy intakes (MEI) and the amount of metabolisable energy (ME) partitioned into milk, maintenance and liveweight (Lwt) changes of Jersey cows of either high genetic merit (HGM) (average milksolids breeding value of 28 kg) or low genetic merit (LGM) (average milksolids breeding value of 11kg). Least-square mean yields for HGM and LGM cows were 327 and 289 kg of milksolids per cow respectively. HGM cows partitioned a significantly higher proportion of MEI into milk than LGM cows in early (0.67 vs 0.63; P<0.01), peak (0.59 vs 0.57; P<0.05), mid (0.58 vs 0.56; P<0.01) and late lactation (0.54 vs 0.51; P<0.01) (HGM vs LGM respectively). In early lactation, HGM cows utilised more body reserves for milk production (-0.05 vs -0.01, for HGM and LGM respectively). These results confirm that HGM cows partition more ME to milk throughout lactation than LGM animals for a range of feeding levels on grazed pasture. The greatest difference occurred in early lactation, resulting in increased body tissue loss and a greater negative energy balance in HGM cows. }, issn = {1176-5283}, author = {Bryant JR and Lopez-Villalobos N and Holmes CW and Pitman GD and Brookes IM} } @conference {41445, title = {The effect of hybridisation on venison production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {222-228}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {Elk x red deer {\textquoteleft}hybrids{\textquoteleft} or technically, crossbreds make a major contribution to New Zealand venison production. Probably over half of the venison produced from young animals (< 2 yrs of age) contains some proportion of elk genes. Elk, and the numerically more significant {\textquoteleft}hybrid{\textquoteright} (50-88\% elk), stags are used as terminal sires over red deer hinds to produce faster growing progeny. The main benefit of the faster liveweight gain is that a high proportion of hybrids reach slaughter live weight (100 kg+) at around 1 year of age to capture current market premiums. Due to the lesser sexual dimorphism of elk than red deer, hybrid females show a greater increase in liveweight gain and weight-for-age over their red deer counterparts than do males. Most of the advantage in yearling weight of hybrids has accrued by weaning and is, thus, captured by the breeder. The absolute and proportional increase in liveweight of hybrids is greater when live weight gain is high (in autumn and spring and under generous feeding levels) and production systems utilising hybrids must recognise this. The metabolisable energy (ME) requirement for maintenance per unit metabolic weight seems to be higher (20\%) for young hybrids than for red deer, although in contrast, the ME cost of liveweight gain may be slightly lower. Small differences in body composition also exist. However, neither of these necessitates major modification to venison production systems. The widespread use of {\textquoteleft}hybrid{\textquoteleft} stags in the New Zealand deer industry has increased the biological efficiency and economic returns to venison production, although increased liveweight gain and weight-for-age must be offset against a somewhat lower reproductive rate in red deer hinds joined with elk or hybrid stags. Hybridisation has also increased the demand for red deer replacement hinds and raised doubts about the wisdom of retaining hybrid hinds as breeding females. }, issn = {1176-5283}, author = {Nicol AM and Judson HG and Taylor AW} } @conference {41427, title = {The effect of sward height on twin and triplet lamb birth weights and survival rates to weaning}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {152-154}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {The differential allocation of pasture between ewes of different bearing/rearing ranks requires a knowledge of the relationship between herbage allowance, intake and production. Few experiments have been conducted in which responses to different pasture allowances have been examined for triplet-bearing/rearing ewes, particularly under continuous stocking management. Published feed requirements for ewes rearing triplets have often been extrapolated from those defined for twin-rearing ewes (Geenty \& Rattray 1987). The sward surface guidelines for feeding single- and twin-bearing ewes have been published and researched under New Zealand conditions (Parker \& McCutcheon 1992; Morris et al., 1993a, 1993b; Morris et al., 1994). There is anecdotal evidence for varying lambing performance and lamb growth rates for triplet-bearing/rearing ewes under pastoral grazing conditions. The national average lambing percentage is increasing to beyond 120\% (MWIES 2002). The proportion of triplets in flocks lambing above 150\% increases at the expense of single-born lambs (Amer et al., 1999). The aim of the research communicated in this paper was to compare ewe and lamb performance in twin- and triplet-bearing/rearing ewes offered various sward height allowances. }, issn = {1176-5283}, author = {Morris ST and Kenyon PR and Burnham DL and Everett-Hincks JM} } @conference {41454, title = {Effect of withholding anthelmintic treatment on autumn growth and internal parasitism of weaner deer grazing perennial ryegrass-based pasture or chicory}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {269-273}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {Sixty-eight weaner deer were allocated to grazing perennial ryegrass-based pasture or chicory from 18 March to 20 May 2002, and within these groups were either regularly treated four-weekly with anthelmintic or treatment was withheld until weight loss or clinical signs of parasitism such as coughing was observed (trigger treatment). Liveweight gain was monitored fortnightly. Five sentinel deer from each of the four groups were slaughtered for nematode counts on 20 May. Deer grazing chicory grew faster than deer gazing pasture (P<0.001). Thirty five percent of trigger-treated deer grazing pasture required treatment for clinical parasitism, but no anthelmintic was required for trigger-treated deer grazing chicory. There was no effect of anthelmintic treatment on average autumn growth of deer grazing chicory, but trigger-treated deer grazing pasture grew at half the rate of regularly treated deer (P<0.01). Deer grazing chicory and treated four-weekly with anthelmintic grew 1.5x faster than deer grazing pasture and treated four-weekly with anthelmintic (P<0.05). This difference in growth of deer grazing chicory and pasture increased to 2.9x when comparing triggertreated deer grazing the two forages (P<0.01). Sentinel trigger-treated deer grazing chicory had half the lungworm population of deer grazing pasture (P=0.13) and 18\% fewer gastrointestinal nematodes (P=0.06). This study shows that grazing young farmed deer on chicory during autumn can increase their resilience to internal parasitism, reducing anthelmintic use whilst increasing deer growth. }, issn = {1176-5283}, author = {Hoskin SO and Pomroy WR and Reijrink I and Wilson PR and Barry TN} } @conference {41401, title = {Effects of different forages on phenol and methylphenol formation in the rumen of sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {40-44}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {Rumen concentrations of the undesirable phenol flavour compounds 4-methylphenol, 3-methylphenol, and phenol, were measured in pooled samples from six rumen-fistulated Romney wethers. Samples were collected at approximately 1 hr intervals for 8 hr after feeding white clover (WC), perennial ryegrass (PRG), or Lotus corniculatus (LC). For all three phenols, the time-course curves for the rumen concentration differed significantly between the three diets (P<0.001) with wide differences in maximum concentrations. For 4-methylphenol, concentrations normalised to crude protein intake (CPI) were very similar. Concentrations of phenol normalised to CPI were very similar for PRG and WC diets but much lower for the LC diet. No 3-methylphenol was detected in the rumen of WC-fed animals. For animals fed the PRG and LC diets, concentrations of 3-methylphenol normalised to acid detergent fibre intake were similar. Differences were also observed in the time to maximum concentration after the commencement of feeding, which was much shorter for 4-methylphenol and phenol (2-3.5 hr) than for 3-methylphenol (6 hr). This study established that feeding different forages resulted in differences in phenol metabolism in the rumen, and provides evidence that 4-methylphenol and 3-methylphenol derive from different dietary sources. }, issn = {1176-5283}, author = {Fraser K and Lane GA and Schreurs NM and Tavendale MH and McNabb WC and Marotti DM} } @conference {41400, title = {The effects of insulin on the milk production of pasture-fed Jersey cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {35-39}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {The aim of this experiment was to determine the effects of insulin on milk protein production in lactating, pasturefed dairy cows. Five lactating rumen-fistulated Jersey cows were subjected to a hyperinsulinaemic euglycaemic clamp (HEC) with and without an abomasal infusion of casein (310g/d) in a two period cross-over design experiment. The HEC significantly reduced milk yield in the control cows compared to casein-infused cows (9.9 {\textpm} 0.5 vs 13.2 {\textpm} 0.5 kg/d, P<0.001). Milk protein yield was significantly higher in the casein-infused cows compared to the control cows (482 {\textpm} 16 vs 421 {\textpm} 16 g/d, P<0.05). The HEC significantly reduced milk protein yield in the control cows compared to casein-infused cows (311 {\textpm} 16 vs 459 {\textpm} 16 g/d, P<0.001). The use of the HEC technique in pasture-fed cows did not result in the milk protein response reported in concentrate-fed cows. }, issn = {1176-5283}, author = {Back PJ and MacKenzie DDS and Davis SR and Harris PM and Lee J} } @conference {41393, title = {Effects of intensive dairy and deer farms on streams and trout fisheries}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {7-10}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {Many streams flowing through agricultural landscapes in New Zealand have poor water quality and biotic indicators. Loss of riparian zone function through vegetation removal and stock access cause changes. Farms where large numbers of cattle and red deer have access to streams result in degraded streams. Restoration of riparian zones and exclusion of stock from streams results in improvements but careful land management is also needed to ensure water quality and instream life is protected.}, issn = {1176-5283}, author = {Rodway M} } @conference {41413, title = {Empirical assessment of the CNCPS model to predict performance of dairy cows fed pasture with silage supplements}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {91-95}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {The goal of this work was to determine the accuracy and utility of the Cornell Net Carbohydrate and Protein System (CNCPS) model to predict milk production from diets based on pasture and forage supplements. Data were obtained from studies in which pasture was complemented with contrasting silages including maize, pasture, sulla, lotus and forage mixtures, comprising 30-40\% of dry matter intake (DMI). Twelve diets were used in this evaluation. DMI, live weight (LW), days in milk, and diet composition were determined during the trials and used as inputs in the model. Across all diets, a significant (P<0.01) relationship existed between predicted and actual values for DMI (r2=0.63), milk yield (r2=0.64) and LW change (r2=0.57) but there were still large unexplained sources of variation and the slopes of the regression lines were significantly (P<0.01) different than 1. No significant mean bias was observed for any of the variables, but the slope of residual differences against predicted values was significantly different from zero (P<0.01 for milk yield and LW change; P<0.06 for DMI). The results indicate a satisfactory prediction of milk production when cows are neither gaining nor losing weight, but that a systematic bias exists probably because of the CNCPS model{\textquoteright}s failure to account for nutrient partitioning. }, issn = {1176-5283}, author = {Chaves AV and Brookes IM and Burke JL and Waghorn GC and Woodward SL} } @conference {41409, title = {Evidence of a genotype by feeding level interaction in grazing Holstein-Friesian dairy cattle at different stocking rates}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {73-76}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {Lactation yields and estimated breeding values (EBVs) for protein, fat and milk were obtained for individual cows in a farmlet trial carried out at Dexcel in Hamilton, using Holstein-Friesian cows, to test for the existence of a genotype by environment interaction across the range of feeding levels, and EBVs typically found on New Zealand pasturebased dairy farms. At very low levels of feeding, with yields of 267 - 307 kg milksolids per cow (kg MS/cow), regression coefficients of lactation yield on EBVs were not significantly different from the expected value of 1. At high levels of feeding, with yields of 383 - 411 kg MS/cow, most of the regression coefficients for yields of protein, fat and milk on EBVs were significantly greater than 1. The results of this study show that at low levels of feeding the actual differences in production between cows, which differ in EBVs correspond to the actual differences in EBVs, whereas at high levels of feeding the difference in milk yields between genetic groups are greater than the difference in EBVs. This constitutes a form of genotype x environment interaction, in which genotype is measured as breeding values, and has important practical and economic implications for dairy farms, and for the expected value of genetic improvements. }, issn = {1176-5283}, author = {Bryant JR and Holmes CW and Lopez-Villalobos N and MacDonald KA and Brookes IM} } @conference {41451, title = {Exploring the potential applications of advanced reproductive technologies in deer farming}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {251-257}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {Advanced reproductive technologies include in vitro embryo production, cloning and genetic modification. However, only the former has been developed in deer. Considerable experimentation is required to develop cloning and transgenesis which is only justified if the deer industry foresees future potential and if animal welfare and public acceptance issues are addressed. Efficient in vitro embryo production and cloning potentially enables rapid dissemination of desired genotypes but relies on accurate identification of genetically superior individuals, which is limiting. In vitro embryo production with oocytes from elite females increases genetic gain and is further enhanced with pre-pubertal animals by shortening generation interval. Utilising sexed sperm to pre-determine gender increases reproductive efficiency. Cloning by nuclear transfer pre-determines the genotype of the animal and could effectively produce cloned stags from progenytested sires for natural breeding. Transgenesis introduces novel genetic modifications into the genome but is limited by the present poor understanding of which genes to manipulate to enhance desirable traits. The advancement of animal genomics will identify both individual genes and entire genotypes to multiply. Nevertheless, these technologies are considerably more difficult to cost-effectively implement than even poorly adopted artificial insemination in an extensive deer industry and will only be relevant for specialised markets.}, issn = {1176-5283}, author = {Wells DN and Berg DK} } @conference {41414, title = {Forage intake and feed conversion efficiency in high-producing dairy herds in New Zealand: a case study}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {96-100}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {In 1998 a three-year dairy farm monitoring programme was established on twelve dairy farms in the southern North Island of New Zealand where production policy had changed from a focus on high production per hectare through high stocking rates to a strategy based on high production per hectare through enhanced production per cow. Results of the third year for nine of these farms revealed a range of apparent feed intake (50,669 - 70,135 MJ ME/cow/year), milksolids production (372 - 432 kg MS/cow/year) and feed conversion efficiency (6.0 - 7.4 g MS/MJ ME intake). There was a significant positive correlation (R2= 0.57, P<0.05) between annual apparent ME intake per cow and annual milksolids production per cow, with a regression coefficient equivalent to 2.5 g MS produced per MJ ME intake, but a significant negative correlation (R2 = 0.80, P<0.01) between ME intake and feed conversion efficiency. The apparent ME intakes measured were 21\% and 8\% higher than theoretical requirements for the farms with higher and lower (compared to each other) milksolids yield values, respectively. This suggests that the high-performance farms may have wasted more feed. Implications for management of feed resources to optimise efficiency in high-production systems are discussed. }, issn = {1176-5283}, author = {Salles PV and Matthews PNP and Holmes CW and Hodgson J and Shadbolt NM} } @conference {41423, title = {Frequency of mastitis and variation in somatic cell counts throughout the lactation in cows managed organically or conventionally; Year 1}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {138-139}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {Interest in organic milk production is growing in New Zealand. At present milk is being collected from 13 organically certified farms in the North Island and 66 farms have been identified as either certified organic or interested in converting from conventional production (Stevenson, 2002). Massey University started a trial on August 2001 to monitor the difference between organic and conventional dairy farming systems, and to provide New Zealand dairy farmers with proven information on differences between the two systems. A key focus of the organic farming system is the maintenance of health and well-being of cows in the herd, without the routine use of conventional methods (e.g., antibiotics). Mastitis has been recognised as the main disease problem. The objective of this report is to present results on the variation in somatic cell counts (SCC), frequency of clinical mastitis (CM) and frequency of acute levels of SCC of cows managed according to either organic or conventional farming practices for the season 2001 to 2002, the first year after the change to organic farming. }, issn = {1176-5283}, author = {Lopez-Villalobos N and Scott J and Smith Z and Holmes CW and Shadbolt NM and Harvey TG} } @conference {41431, title = {Genetic and environmental parameters for lambing behaviour in Merino lines divergently selected for ewe multiple rearing ability}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {169-172}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {Data were recorded for lambing behaviour of approximately 1000 Merino ewes lambing over a 10-year interval from 1993 to 2002. The resource population was divergently selected from the same base population since 1986, either for (H line) or against (L line) maternal multiple rearing ability. Line differences (P < 0.05) favoured H line ewes for length of parturition and maternal cooperation score. Heritability was estimated at 0.17 {\textpm} 0.04 for length of parturition, 0.11 {\textpm} 0.04 for maternal cooperation score and 0.20 {\textpm} 0.04 for the interval ewes remained on or near to the birth site. A small service sire effect for length of parturition in ewes amounted to 0.03 {\textpm} 0.02. Maternal cooperation score was genetically related to the time spent on or near to the birth site (0.53 {\textpm} 0.18). Genetic divergence between lines was detected in all three traits. These results and the obtained parameter estimates indicate that selection for improved multiple rearing ability was feasible in paddock-reared sheep flocks.}, issn = {1176-5283}, author = {Cloete SWP and Van Wyk JB and Scholtz AJ and Gilmour AR} } @conference {41447, title = {Genetic improvement of red deer}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {233-236}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {Deer breeding has made significant progress in a relatively short time. However, opportunities exist to make further advances in several areas. Development and implementation of across-herd breeding value analyses could significantly benefit the deer industry through providing opportunity to accelerate rates of genetic gain, and by providing commercial stag purchasers with objective information on which to base stag selection. This will require the development of standard recording protocols and a central performance database, but the technical issues surrounding this are solvable and suitable models exist in other livestock industries. With changing composition of industry returns, deer farmers and breeders might re-evaluate whether they are best served by selection for specialist velvet and venison lines, or whether a dual-purpose animal remains the best option. There may also be value in broadening the traits objectively described to include aspects of venison production other than growth. }, issn = {1176-5283}, author = {Archer JA} } @conference {41440, title = {Genetics of lamb survival}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {201-203}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {Data from seven commercial New Zealand sheep flocks were analysed to quantify the extent to which lamb survival in New Zealand sheep is influenced by genetic factors. Estimates of direct and maternal genetic variance components, and the effects of inbreeding in either the lamb or the dam on lamb survival, were found to vary significantly across flocks. Direct heritability estimates ranged from 0.008 to 0.070, while maternal heritability estimates ranged from 0.002 to 0.075. Inbreeding in the lamb showed a statistically significant (P<0.05) effect on survival in three of the seven flocks, ranging in value from -0.17 to -0.29\% reduction in lamb survival for a 1\% increase in inbreeding coefficient. Inbreeding of the lamb{\textquoteright}s dam had a statistically significant effect (P<0.05) on survival in two of the seven flocks, taking values of -0.32 to -0.71\% reduction in lamb survival for a 1\% increase in the dam{\textquoteright}s inbreeding coefficient. It is recommended that lamb survival records be transformed to a constant variance within flock and year prior to estimation of breeding values, but that no transformation to either a logit or probit scale within the statistical analysis is required. Inbreeding coefficients for both the lamb and the lamb{\textquoteright}s dam should be included as linear covariates in the mixedmodel analysis of lamb survival breeding values. }, issn = {1176-5283}, author = {Amer PR and Jopson NB} } @conference {41434, title = {Heritability of Johne{\textquoteright}s disease and survival data from Romney and Merino sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {179-182}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {Eight years of health records for ovine Johne{\textquoteright}s disease (OJD) from a long-term breeding trial with Romneys and Merinos at AgResearch{\textquoteleft}s Tokanui Station were analysed, to study the quantitative genetics of animal resistance/susceptibility to OJD. Necropsy records were used in preference to serology to determine OJD status. A total of 2348 Romney and 1297 {\textquoteleft}Merino{\textquoteleft} ewe records (5 groups: two purebred Merino groups (Australian imported superfine and NZ purebred Merino), two Merino x Romney halfbred groups and a superfine Merino back-cross) were analysed for OJD and survival, comprising animals born between 1971 and 1978. Few males were retained past two years of age, so disease and survival data on males were excluded. Romney ewes had a mean lifetime incidence of OJD of 3.49\% (range, by year of birth, 2.11 to 5.00\%), whilst the mean for Merino ewes was 4.78\% (range, by year of birth, 0.0 to 7.74\%). The breed contrast approached significance (P<0.051). The mean age at OJD incidence was 3.44 {\textpm} 0.09 years for Romneys, compared with a mean age for surviving females in the sample of 5.04 {\textpm} 0.02 years (P<0.001). Corresponding means for Merinos were 3.38 {\textpm} 0.13 and 5.00 {\textpm} 0.04 years, respectively (P<0.001). The heritability of lifetime incidence of OJD, considered as a binomial trait and using animal-model restricted maximum likelihood methods, was estimated as 0.07 {\textpm} 0.14 and 0.18 {\textpm} 0.11 for Romneys and Merinos respectively, giving an overall value (pooled within breeds) of 0.14 {\textpm} 0.09. Adjusting for Merino group in the relationship matrix (rather than as a fixed effect) led to a heritability for Merinos of 0.24 {\textpm} 0.09. These estimates may be biased upwards by {\textquoteleft}vertical transmission{\textquoteleft} of OJD organisms from dam to offspring. The heritability of age at death/culling had values of 0.11 {\textpm} 0.04 and 0.16 {\textpm} 0.05 for Romneys and Merinos respectively, with a pooled value of 0.13 {\textpm} 0.03. With the low heritability estimates for OJD in Romneys it is concluded that traditional breeding methods to reduce the incidence would be slow or unsuccessful; however, for Merinos, selection could begin to reduce the incidence, but ranking later generations may become difficult. }, issn = {1176-5283}, author = {Hickey SM and Morris CA and Dobbie JL and Lake DE} } @conference {41453, title = {Impact of diseases on the NZ deer industry}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {262-268}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {The financial impact of a range of clinical and subclinical diseases, and mortalities on deer farms is difficult to assess because there are insufficient accurate survey data of their prevalence, causes or production losses on a national basis. However, estimates suggest that clinical disease and current disease control measures may cost the deer industry in excess of $29 million per annum currently, and it may be speculated that at least that amount may be lost due to loss of production from subclinical diseases, resulting in potential costs and losses approaching $60 million per annum. Application of existing knowledge of disease control and prevention on individual farms would significantly reduce this wastage immediately. In addition, investment to improve technology for disease diagnosis, control, prevention and/or eradication, along with adoption of that technology should yield significant dividends for the deer industry. }, issn = {1176-5283}, author = {Mackintosh CG and Wilson PR} } @conference {41406, title = {Interaction of gastro-intestinal nematodes and calf weaning management on beef cattle growth}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {61-65}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {An experiment was undertaken to study the effects of calf weaning management on growth rates and susceptibility to gastro-intestinal nematodes. Treatments were: weaned at 6 months (of age) and normal anthelmintic use; weaned at 6 months and no anthelmintics; weaned at 6 months yet grazed with dam until 9 months and no anthelmintics; weaned at 9 months and no anthelmintics. At 9 months of age, calf live weights for the four treatments were: 264, 253, 265 and 308 kg respectively (SED = 2.0). Faecal-egg counts and serum pepsinogen levels were not affected by weaning date. Milk consumption by the later weaned calves was 4.2 kg/day, resulting in herbage intakes being 25\% lower than calves in other treatments (P<0.01). When suckling calves to 9 months of age, the cost of this milk production to the cow was 26 kg live weight (SED = 6.3). Later weaning gave a substantial increase in calf live weight (P<0.001), which can be attributed to milk consumption. Faecal-egg counts and serum pepsinogen levels indicated that milk consumption did not have a direct effect on gastro-intestinal nematode burdens. }, issn = {1176-5283}, author = {Boom CJ and Sheath GW and Vlassoff A} } @conference {41433, title = {Lack of genetic association of markers near the leptin gene with carcass fat content in Coopworth sheep lines selected for and against fatness}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {176-178}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {Leptin is an important hormone in controlling food intake and energy expenditure in mammalian species. The present study evaluated levels of serum leptin in Coopworth sheep selected for and against subcutaneous fat depth for 10 generations. Significant differences in serum leptin concentrations were found between fat and lean sheep (P<0.05) and between male and female sheep (P<0.01). Serum leptin concentration was positively correlated with carcass fatness and there was a clear relationship between mean progeny serum leptin concentrations and the breeding value for fat. Serum leptin concentrations were greater (P<0.05) in lambs selected from the fat line (2.69ng/ml) than in lambs selected from the lean line (2.18ng/ml). A microsatellite marker, OarCP26, already mapped on sheep chromosome 4 (OAR4) was located in a sheep yeast artificial chromosome (YAC) clone that was positive for the leptin gene (LEP). This confirmed the independent assignment of LEP, mapped using a sheep cell hybrid panel, to OAR4. No significant differences in the allele frequencies of OarCP26 and two other flanking markers (TGLA116 and OarHH335) were detected in the lean and fat selection lines suggesting genes other than leptin are causing the differences in fat between the lean and fat Coopworth lines. }, issn = {1176-5283}, author = {Campbell AW and Broad TE and Jopson NB and Burkin HR and Dodds KG and Veenvliet BA and Bain WE} } @conference {41435, title = {Lessons to NZ sheep breeders from other species and other countries}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {183-186}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {The SIL system for genetic improvement of productivity in the New Zealand sheep flock has been reviewed. It is technically well designed, and provides first rate genetic information to a range of breeder users. However, the availability of such a system for performance recording and genetic evaluation does not guarantee that it will be fully utilised by industry to achieve high rates of genetic gain for economically important breeding objectives. Ways of maximizing participation by the nucleus sector and of maximising the choice among genetically comparable rams for the commercial sector need to be pursued.}, issn = {1176-5283}, author = {Piper LR and Banks R} } @conference {41392, title = {LIC Lecture - The development of environmental best practices for intensive dairying}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {3-6}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {Research since 1995 has focused on soil, fertiliser and animal management factors affecting soil and water quality in intensive dairy systems on imperfectly to poorly drained soils in Southland and Otago. Derived from this on-farm research, best practice for effluent, fertiliser and soil management to ensure that required environmental standards are attained, is outlined. }, issn = {1176-5283}, author = {Monaghan RM and Morton JD and McDowell RJ and Drewry JJ and Thorrold BS} } @conference {41396, title = {A long-acting injectable Se/Vitamin B12 product to prevent Se and Co deficiency in lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {18-20}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {The efficacy of a novel injectable formulation containing barium selenate (BaSeO4) and microencapsulated Vitamin B12 was evaluated in groups of lambs (n=10) over 246 days in terms of changes in blood Se and serum Vitamin B12 concentrations as well as growth responses. Mean blood Se and serum Vitamin B12 concentrations of the untreated control lambs were 125 {\textpm} 9 nmol/L and 508 {\textpm} 21 pmol/L, respectively. The formulation increased blood Se to 2100 nmol/L at day 64 before decreasing to 761 nmol/L at day 246. Likewise, serum Vitamin B12 reached a peak of 1950 pmol/L at day 31 before decreasing to 577 pmol/L at day 246. The treatment significantly increased (P<0.05) daily weight gains from 125 {\textpm} 4 to 136 {\textpm} 4 g/day. An injectable Se/Vitamin B12 product containing 12 mg Se as BaSeO4 and 3 mg Vitamin B12 per dose administered at docking was effective in increasing and maintaining the Se and Vitamin B12 status of lambs for at least 246 days. }, issn = {1176-5283}, author = {Grace ND and Knowles SO} } @conference {41448, title = {Maintaining product quality from the farm gate to the processing facility}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {237-242}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {There is substantial evidence that pre-slaughter events (mustering and holding in yards, transport, lairage and preslaughter handling) have negative effects on product quality through bruising, hide damage and muscle pH. To minimise these negative effects, use of deer-specific, good stock handling procedures and appropriately designed facilities are essential. The duration of pre-slaughter events and human presence should be minimised. Yard pens should be appropriately sized, dark, quiet, and deer should be kept in familiar groups. Adherence to existing guidelines for transport, careful driving, and avoiding transport during hot weather are desirable. Showering deer upon arrival at the processing plant plus provision of water in lairage pens probably prevents dehydration. Conversely, showering under some conditions may add to stress and bruising damage in lairage. Research proposed to improve pre-slaughter handling includes taming and selection for tractable deer, definition of appropriate handling techniques and improved facility designs. Further work is also required to identify optimal practices for lairage, showering, washing and feeding. }, issn = {1176-5283}, author = {Pollard JC and Littlejohn RP and Scobie DR and Pearse AJT and Stevenson-Barry JM} } @conference {41438, title = {Making better use of the SIL genetic engine}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {194-196}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {Developments in genetic evaluation techniques used in the SIL genetic engine have increased the accuracy with which estimated breeding values are calculated and have provided maternal breeding values for growth and survival traits. Although these will assist progressive breeders, a considerable number of breeders would gain greater benefits from improvements in data recording techniques to more fully utilise the potential of the SIL genetic engine to identify genetically superior animals. In particular, reproductive and survival data are often recorded less than optimally. Ewes culled at pregnancy scanning, barren ewes, lambs born dead and lamb deaths from birth to weaning require particular attention. }, issn = {1176-5283}, author = {Newman S-AN} } @conference {41425, title = {Metabolic changes in ewes shorn during mid-pregnancy}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {144-148}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {Previous work has shown that, under appropriate circumstances, mid-pregnancy shearing results in an increase of both the birth and weaning weights of multiple-born lambs. However, the physiological mechanisms for this response are poorly understood. This paper attempts to clarify the link between mid-pregnancy shearing and heavier lamb weights by investigating the metabolic changes that occur in ewes that are shorn in mid-pregnancy. Twenty-four twin-bearing ewes were assigned to one of two treatment groups; mid-pregnancy shorn (70 days after the mid-point of mating: P70) or unshorn. Groups were balanced for ewe age and weight. Blood samples were collected from all animals on days P53, P69, P81, P84, P90, P109 and P130, for measurement of concentrations of triiodothyronine (T3), thyroxine (T4), cortisol, glucose, non-esterified fatty acids (NEFA) and beta-hydroxybutyrate. Lamb birth weight, girth and crown-rump length (CRL) measurements were collected within 24 hrs of birth. Lambs were weighed at weaning. Mid-pregnancy shearing increased lamb birth weights and girths by 0.43 kg (P<0.05) and 2.18 cm (P<0.05) respectively although these differences were not significant once adjusted for date of birth. There was no effect on CRL. Plasma concentrations of T3 and T4 were significantly higher in mid-pregnancy-shorn ewes relative to unshorn ewes at both P81 (P<0.01) and P84 (P<0.01 and P<0.05 respectively) and T4 concentrations tended to be higher at P90 (P<0.10). There was a significant effect of shearing treatment at P81 on plasma NEFA concentrations (P<0.05). There were no significant post-shearing differences in mean cortisol, glucose or beta-hydroxybutyrate concentrations. The study proposes that the most likely mechanism by which mid-pregnancy results in higher lamb birth weights is by increasing maternal thyroid hormone concentrations, resulting in an increase in fat mobilisation causing increased NEFA concentrations in the maternal blood supply, which in turn improves placental nutrition and, thus, lamb birth weight. }, issn = {1176-5283}, author = {Sherlock RG and Kenyon PR and Morris ST and Parkinson TJ} } @conference {41399, title = {Metabolic responses to glucose challenge in New Zealand and overseas Holstein-Friesian dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {31-34}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {North American and Dutch Holstein-Friesian (HF) cattle have undergone genetic selection for increased milk production, however, at the same time, reproductive efficiency has decreased. Overseas HF also have greater propensity to mobilise body reserves during early lactation than New Zealand HF cows. It is possible that reproductive differences are a consequence of metabolic and endocrine differences between the strains. This trial was designed to investigate effects of genotype and diet on endocrine response to a challenge of intravenous glucose in HF cows. Twenty-five HF cows of New Zealand (NZ; n=13) and Overseas (OS; n=12) origin, were fed either pasture (Grass; n=12) or a total mixed ration (TMR; n=13) in a 2x2 factorial design. At two weeks postpartum, they were challenged with 300mg of glucose/kg live weight. Data were analysed for effects of genotype and diet. Following glucose challenge, the NZ TMR cows had higher plasma insulin concentrations than the NZ Grass, resulting in a significant interaction between diet and genotype in the area under the response curve; but the OS groups had similar patterns. Mean plasma leptin concentration was higher in NZ TMR than in NZ Grass, OS TMR or OS Grass. Plasma concentrations of glucose and IGF-I were not affected by genotype or feed regime. These results demonstrated metabolic differences between the strains and also diets. A better understanding of the genetic and nutritional basis of hormonal regulation of nutrient partitioning will be important to develop nutritional strategies to meet the requirements of lactating cows with different genotypes, and to find ways to improve reproductive efficiency. }, issn = {1176-5283}, author = {Chagas LM and Clark BA and Rhodes FM and Blache D and Kolver ES and Verkerk GA} } @conference {41421, title = {Methane and carbon emissions from conventional pasture and grain-based total mixed rations for dairying}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {128-132}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {Comparisons between cows grazing pasture or fed total mixed rations (TMR) show on average less milk production from pasture but a higher methane yield per milk or milksolids production from the pasture diet. The implication that TMR are associated with relatively lower greenhouse gas (GHG) emissions than pasture required an assessment of all production costs associated with both systems because TMR requires extensive cultivation and processing of grains and silages which form the bulk of the diet. A partial life cycle analysis of GHG (excluding nitrous oxides) was carried out for separate 250 cow herds located in Waikato (pastoral grazing) and Canterbury (cropping land for the TMR). This demonstrated much higher methane and carbon dioxide emissions, (kg CO2 equivalents/kg milk) from cows fed TMR (1.53) relative to pasture (0.84). The principal cause of the high value for TMR were carbon losses from soil cultivation which accounted for 64\% of emissions, expressed as CO2 equivalents compared to 24\% from pasture. Enteric methane accounted for 28\% of GHG from TMR and 64\% from pastoral systems. The remaining 8\% and 12\% from TMR and pastoral grazing respectively, were attributed to fertilisers, cultivation and processing.}, issn = {1176-5283}, author = {van der Nagel LS and Waghorn GC and Forgie VE} } @conference {41422, title = {Modelling optimum switch date from twice- to once-daily milking in dairy herds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {133-137}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {The production of a dairy herd was simulated at two different stocking rates (3.4 cows/ha and 4.0 cows/ha) and two seasonal conditions (an average and a dry Waikato summer). Cows were milked twice-daily (TDM) for varying periods, before being switched to once-daily milking (ODM) for the remainder of the lactation. Switching from TDM to ODM during the milking season reduced the total production of the herd. With 3.4 cows/ha in an average summer, at a break-even value of labour of $100 /milking ($200 /milking) the optimum switch-over date was January 13 (October 21); a dry season brought forward this date by approximately two weeks. Increasing payout increased the break-even value of labour at a given switch-over date. Under a commonly used farmer industry guideline, break-even labour values under average (dry) conditions were $53.47 /milking ($61.47) for 3.4 cows/ha and $36.07 /milking ($33.98) at 4.0 cows/ha. A stocking rate of 4.0 cows/ha switching to ODM after peak production had a lower cash surplus than a 3.4 cows/ha stocking rate with TDM due to additional ($30,000) feed costs with the higher stocking rate. These results suggest a formal approach could be used to complement industry guidelines in deciding when to switch from TDM to ODM. }, issn = {1176-5283}, author = {Westbrooke VCF and Dooley AE and Vetharaniam I} } @conference {41444, title = {Optimising calf growth of red deer in summer and autumn}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {218-221}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {The potential for red deer calves to grow is at its maximum during lactation and the early autumn before the first winter. Capturing this potential is one key to economic success in venison production. On-farm and experimental results have shown a wide range of live weight gains during these periods. Feed allowance during this time should ensure that residual pasture mass should not be below 1200-1500 kg DM/ha, while pasture allowance should be above 4 kg DM/d. Feed quality needs to be above 11 MJ ME/kg DM or a pasture should contain more than 70\% green leaf. Poor liveweight gain in calves during late lactation and autumn delays subsequent slaughter and may lead to a substitution of weaners for hinds, decreasing the net productivity of a farming system. Strategies for improving both the amount and quality of feed on offer during summer and autumn include improved spring management, use of grasses with later flowering dates, increasing the use of specialist high-quality feeds such as red clover, chicory and lucerne, using management to increase white clover content and using brassicas or concentrate feeds if other options fail. }, issn = {1176-5283}, author = {Stevens DR and Corson ID} } @conference {41410, title = {Postpartum anoestrous intervals and reproductive performance of three genotypes of Holstein-Friesian dairy cattle managed in a seasonal pasture-based dairy system.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {77-81}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {An extended postpartum anovulatory interval (PPAI) is the major form of infertility in New Zealand (NZ) dairy cattle. Recently, Holstein cows, originating from North American genetic strains (Overseas; OS), have been widely used in NZ. Worldwide, there is concern over an apparent decline in the fertility of Holstein-Friesian dairy cattle. This study determined whether differences existed in PPAI, BCS and parameters of reproductive performance between NZ and OS Holstein-Friesians. One hundred and forty-six records from 88 NZ animals of high genetic merit for milk production (NZH), 81 records from 48 NZ animals of low genetic merit (NZL), and 137 records from 88 OS high genetic merit animals that calved in Years 1 (all two-year-olds) and 2 (two- and three-year-olds) were included. Over both years PPAI in two-year-olds were significantly shorter in OS (20 days shorter) and NZL (12 days shorter) than in NZH animals (P<0.05). Body condition score at calving, and BCS loss from calving to four weeks postpartum were not different between strains. In Year 1 of the study significantly more NZH than NZL or OS 2-year-olds were treated for anoestrus prior to the start of mating (P=0.001). Other measures of reproductive performance did not differ significantly between strains. The differences in PPAI require further investigation. }, issn = {1176-5283}, author = {McNaughton LR and Verkerk GA and Parkinson TJ and MacDonald KA and Holmes CW} } @conference {41395, title = {Postprandial indole and skatole formation in the rumen when feeding white clover, perennial ryegrass and Lotus corniculatus}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {14-17}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {In some international markets, meat and milk products from pasture-fed animals is associated with an undesirable pastoral flavour and odour. Sensory evaluation and chemical analysis of products has associated these flavours and odours with the presence of skatole and indole. Skatole and indole are formed in the rumen from the degradation of dietary protein. Condensed tannins (CT) have been shown to reduce protein degradation in the rumen and could reduce the formation of skatole and indole. This study investigated the concentrations of skatole and indole in the rumen of sheep after feeding white clover (WC), perennial ryegrass (PRG) and the CT forage, Lotus corniculatus (LC). Six rumen-fistulated Romney wethers were fed the cut forages and rumen contents sampled at intervals after the start of feeding. Feeding WC resulted in higher (P<0.05) peak concentrations of indole and skatole in the rumen per kilogram of crude protein eaten (CPI) compared to PRG and LC. There was a higher peak concentration of indole, but not skatole, in the rumen of sheep fed PRG compared to sheep fed LC (P<0.05). Feeding LC resulted in lower peak concentrations of skatole compared to feeding WC and lower peak concentrations of indole than when feeding WC or PRG. White clover in pastures may be a key factor of the high skatole and indole contents in meat and milk products obtained from pasture-based grazing systems. CT forages seem a likely solution to reducing ruminal skatole and indole formation. }, issn = {1176-5283}, author = {Schreurs NM and Tavendale MH and Lane GA and Barry TN and Marotti DM and McNabb WC} } @conference {41398, title = {Predicting Delta9-desaturase activity and the association with conjugated linoleic acid (CLA) concentration in bovine milk}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {25-30}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {The major source of cis-9, trans-11 conjugated linoleic acid (CLA) in bovine milk is from the post-ruminal conversion of trans-11 C18:1 (TVA) by D9-desaturase. Activity of D9-desaturase is predicted from the product/substrate ratios of fatty acids dependant on the enzyme. Data from three experiments was investigated. Cows selected for having soft or hard milk fat were fed ruminally protected oilseed in spring 1999, and autumn 2000 or crushed full-fat rapeseed in autumn 2001. Cows with harder milk fat had higher concentration of milk fat (P<0.001), and lower concentrations (P<0.001) of TVA and CLA. Feeding ruminally protected oilseed in spring had no effect on milk fat, TVA or CLA concentrations but in autumn increased (P<0.001) milk fat concentration. Feeding crushed rapeseed depressed (P<0.001) TVA and CLA concentrations. Ratios of fatty acid pairs dependent on D9-desaturase (C10:1/C10:0, C16:1/C16:0 cis-9 C18:1/C18:0 and CLA/TVA) were lower in milk from cows with harder milk fat and the C12:1/C12:0, C14:1/C14:0 ratios were similar for soft and hard milk fat cows. Feeding ruminally protected oilseed decreased (P<0.001) all ratios except for C12:1/C12:0 in autumn 2000. Feeding rapeseed had no effect on the product/substraight ratios except the cis-9 C18:1/C18:0 ratio. None of these ratios were associated with milk fat CLA concentrations in spring however in autumn C14:1/C14:0 and C16:1/C16:0 were positively associated (P<0.05). Significant associations (P<0.001) between the milk fat cis-D9 C18:1/C18:0 ratio and CLA concentration and between TVA and CLA concentrations were also evident. This suggests that milk fat CLA concentrations may be influenced more by the availability of TVA than by the variation in the activity of D9-desaturase. }, issn = {1176-5283}, author = {Thomson NA and Chand A and Kay JK} } @conference {41391, title = {Presidential Address 2002 Where is science taking society and where is society taking science?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {1-2}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {Pharming Hildagaard, a fringe theatre production telling of human cloning (Figure 1), is one way our society deals with the contentious nature of modern scientific developments. The fringe theatre production set at a fictitious research organisation in Hamilton, may have been a fantasy, sensationalist, and perhaps contained dodgy science (M. Servian, personal communication), but it was a story that attempted to engage the issues that cloning raises. While this may have been fringe or experimental theatre, opposition to genetic modification is more mainstream and {\textquotedblleft}coming to a field near you{\textquotedblright}. Questions have been asked over where science is taking agriculture (Anon, 1998) and we might also ask where science is taking society, or where society is taking science? I want to use a number of great thinkers to reflect on how we deal with these questions, and thus how we deal socially with science. }, issn = {1176-5283}, author = {Fisher MW} } @conference {41402, title = {Protein concentration in the rat maternal diet programs appetite and glucose metabolism in the offspring}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {45-48}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {The effect of dietary protein concentration throughout gestation and lactation on maternal appetite, and appetite and glucose metabolism of the offspring, was investigated. Female Sprague-Dawley rats were fed diets containing either 20\% whey protein (control; C, n=20) or 5\% whey protein (low-protein; LP, n=30) through gestation and lactation. LP mothers gained less weight during gestation (88 vs. 136 g, SED=18, P<0.01), and consumed less food during lactation (451 vs. 902 g, SED=77, P<0.001). C offspring were heavier at birth (6.5 vs. 5.3 g, SED=0.5, P<0.05), consumed more food (273 vs. 178 g, SED=15, P<0.05), and gained weight more rapidly (5.9 vs. 3.7 g/day, SED=0.4, P<0.001) than LP offspring. LP offspring had lower fasted blood glucose at 40 (2.2 vs. 3.5 mmol/L, SED=0.4, P<0.01) and 50 (2.9 vs. 4.8 mmol/L, SED=0.2, P<0.001) days of age and were more sensitive (P<0.001) in response to a glucose challenge at 30 (498 vs. 615 mmol/L min, SED=24), 40 (557 vs. 700 mmol/L min, SED=24) and 50 (535 vs. 781 mmol/L min, SED=44) days of age. These results show that maternal dietary protein concentration during gestation and lactation programs appetite and glucose metabolism in the offspring. }, issn = {1176-5283}, author = {Barnett MPG and Harris PM and Cooper GJS} } @conference {41437, title = {Ram Focus - matching rams to buyer flocks}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {190-193}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {A new software package has been developed to assist ram breeders to target rams to buyers{\textquoteleft} flocks. "Ram Focus" leads the potential buyer through a short series of questions relating to the buyer{\textquoteright}s current levels of animal performance, aims and future expectations. The answers to these questions are used to calculate economic values for individual traits, which are subsequently combined into an index customised for the buyer. The end result is that Ram Focus reranks the suitability of rams for alternative commercial flocks. Examples are presented of how the suitability of rams changes between commercial flocks, first using examples of differing reproductive performance, and second, differences in expectations of a drench failure.}, issn = {1176-5283}, author = {Jopson NB and Amer PR} } @conference {41415, title = {Ranking maize hybrids for silage quality and milk production in pasture-based dairying}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {101-106}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {A large database (n=1611) of maize hybrid nutritive characteristics was developed by sampling 42 maize hybrids from three replicate plots at 100 Pioneer Research sites during 2000, 2001, and 2002. Compared to changes from year to year, differences in nutritive quality across hybrids of different maturity were small. Differences in maize hybrid quality accounted for $34 extra milk income per tonne of maize silage DM, whereas the differences in hybrid yield had a much larger impact on milk income ($8672/ha maize grown). Maize hybrids were ranked similarly for milk production potential, although the rankings were much closer, and sometimes equal for hybrids when fed in a New Zealand pasture system compared to a US total-mixed-ration system. Being able to select maize silage hybrids in New Zealand based on the extra milk they are likely to produce will be of benefit to dairy farmers, especially as inclusion rates of maize silage increase.}, issn = {1176-5283}, author = {Kolver ES and Densley R and Miller D and Williams I and Sapienza DA} } @conference {41424, title = {Recognising the limits to live weight-reproduction relationships in ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {140-143}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {The relationship between joining live weight and ovulation rate and number of lambs born was examined in a composite flock of small- and large-framed ewes. Approximately equal numbers of small- (n = 315) and large (n = 305) framed, mixed-age ewes of equal average condition score, selected in the same proportion from 9 commercial flocks (mainly Coopworth), were managed together from early March to pre-lambing. The average pre-joining live weight ({\textpm}SD) of small-framed ewes (61.3 {\textpm}6.35 kg). was significantly (P<0.001) lower than that of large-framed ewes (71.1{\textpm}6.58 kg). Ewes were joined with 14 Coopworth ram hoggets fitted with ram harnesses on 8 April. Ewes marked by rams were temporarily removed from the flock every 7 days for 21 days and ovulation rate (0, 1, 3, 4) recorded by laparoscopy the following day after fasting. Pregnancy status (0, 1, 2 or more) was recorded by ultrasonography on 4 July. Ewes were fully recorded at lambing. The mean ovulation rate (OR) of small-framed ewes was significantly lower (1.76, P<0.05) than that of large-framed ewes (1.92). The regression of OR on joining live weight (jLW) was significant (P<0.001) for small-ewes (OR = 0.0216 x jLW + 0.463) but there was no relationship between OR and jLW in large-framed ewes. Maximum OR (1.92) was predicted to occur at 67.5 kg jLW. The results of this study indicate an upper limit to the live weight ovulation rate relationship. Compared on the basis of equal ewe live weight per ha, OR per ha was 12\% higher for small- than large-framed ewes. }, issn = {1176-5283}, author = {Rutherford L and Nicol AM and Logan CM} } @conference {41443, title = {Reflections and visions in the deer industry}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {212-217}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {The deer industry has changed markedly in the last 10 years in terms of productive capacity, market size, the nature of industry participants and their representative structures. It has survived and generally thrived despite significant business and global upheavals over this period. However, a number of fundamental issues remain unresolved and represent the industry{\textquoteleft}s greatest challenges. As the pace of change in technology, consumer needs and global markets picks up, the ability of the deer industry to continue to adapt to change and to respond decisively to local and global issues that arise will be increasingly important for its continued growth and success. Even within a two year horizon there are a number of critical decisions that will need to be taken that will determine the industry{\textquoteright}s performance longer term. }, issn = {1176-5283}, author = {Loza MJ} } @conference {41411, title = {Relationships between milk protein percentage and reproductive performance in Australian dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {82-86}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {The InCalf Project included a large, prospective, observational field study that described the reproductive performance of 29,462 dairy cows in 168 herds throughout Australia. Milk protein percentage was identified as one of six factors associated with herd reproductive performance. In this further study, a subset of the original database was used and then refined to only include Holstein cows with between one and five milk production records during the first 120 days of lactation in seasonal-calving herds which carried out artificial insemination (AI) for at least the first six weeks of the mating period. This subset then comprised 8,795 cows in 66 herds. Cows in the subset were divided into four quartiles based on early lactation milk protein percentage and five intervals from calving to mating start date (MSD). Three week submission rate and six-week in-calf rate were lower (P<0.001) and the 21-week not-in-calf rate was higher (P<0.001) for cows in the lowest compared to the highest quartiles for milk protein percent. The association between milk protein percentage and reproductive performance was driven mainly by the incidence of non-cycling cows with consequent effects on submission rate in the first three weeks of AI as well as in the second three weeks. In conclusion, late calving cows with low milk protein percentage were at the greatest risk of not being submitted for AI and remaining not in-calf at the end of a relatively long mating period of 21 weeks. }, issn = {1176-5283}, author = {Fahey J and Morton J and Macmillan KL} } @conference {41449, title = {Reproductive productivity of young red deer hinds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {243-246}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {Reproductive productivity of rising-two-year old red deer hinds on New Zealand deer farms has been a prominent issue over the last 10 years. On average, 16\% of young hinds fail to establish pregnancy in their second year, although this figure masks wide between-farm variation. A growing body of ultrasound scanning data implicates failure of ovulation and/or conception at 16 months of age as the main influence on pregnancy rate. While such puberty failure in red deer has often been attributed to poor nutrition and failure of hinds to attain a critical threshold live weight of 65 -70 kg at 16 months, data on growth rates of young hinds from numerous farm monitoring programmes around the country largely debunk this concept. This paper reviews the potential causes of reproductive failure in young red deer, including the putative and actual influences of seasonal, social, stress and genetic factors on puberty failure. An emerging theme is the strong interplay of various environmental and genetic factors in determining the incidence of puberty. }, issn = {1176-5283}, author = {Asher GW} } @conference {41450, title = {Research on calving environments for farmed red deer: a review}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {247-250}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {This review describes past research on suitable calving environments for farmed red deer and presents ideas on future topics for research. Neonatal mortality on deer farms is common, claiming 10-12\% of calves born on average. Research carried out in the 1970s and observations of wild red deer identified three factors that were required to minimise behavioural problems and subsequent mortality of young calves: isolation of the hind from other deer, vegetative cover for the calves to hide in, and lack of disturbance by people. Subsequent studies have substantiated these observations but the needs for isolation and lack of disturbance cannot be readily fulfilled on intensive deer farms. Selection for deer that are tolerant of other deer and humans at calving time, and taming deer so that disturbance by humans is lessened, are areas in which future research may prove worthwhile. }, issn = {1176-5283}, author = {Pollard JC} } @conference {41404, title = {A single-nucleotide polymorphism on Calpain-1 is associated with meat tenderness in cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {53-56}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {Variability in tenderness remains a major concern to the meat industry, and our objective was to identify genetic effects on beef meat tenderness, in animals treated alike, and under similar post-mortem processing conditions. A quantitative trait locus (QTL) for beef tenderness has been located on the same region of chromosome 29 in a United States Department of Agriculture (USDA) study and in our research. Micro-calpain, or calcium-activated neutral protease (CAPN1), has been identified as a candidate gene. The calpain/calpastatin system is involved in the change of tenderness with time, by regulating post-mortem proteolysis. The CAPN1 gene was sequenced by USDA workers who identified single-nucleotide polymorphisms (SNPs) in two exons. These results were followed up as part of the AgResearch Jersey-Limousin Beef QTL trial, where steak samples were obtained from the longissimus dorsi of 416 animals slaughtered at about two years of age. The segregating USDA and NZ families were both heterozygous for one of these SNPs, on exon 9, and this region was predicted to alter the protein sequence by the substitution of alanine for glycine in Domain II. Both families were genotyped for these two SNPs, as well as for six intronic polymorphisms, to define haplotypes. Analysis of tenderness measurements in the NZ data (n=81 animals) showed a difference between paternal CAPN1 haplotypes, with the SNP encoding alanine at amino acid number 316 being associated with more tender meat (decreased shear force) relative to the SNP encoding glycine (P<0.00001). The association of the maternal haplotypes with meat tenderness phenotypes (P<0.01) was also consistent with the hypothesis of CAPN1 as the gene underlying the QTL effect. The sire and dam effects together accounted for over 30\% of the residual variance in tenderness. Our results show that a single SNP test in the laboratory can distinguish genetically tender and genetically tough animals at any age. }, issn = {1176-5283}, author = {Cullen NG and Page BT and Morris CA and Hickey SM and Dobbie PM} } @conference {41407, title = {Strategies to encourage adoption: a case study of New Zealand farmers and their possum control practices}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {66-68}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {Ecological scientists and policy agencies have identified possums (Trichosurus vulpecula) as a pest of both biodiversity and agricultural production. However it has been unclear whether farmers would take action to control possums for biodiversity reasons if their potential threat to agriculture was reduced. In 2002 a survey was made of New Zealand livestock farmers, of whom 85\% had control measures in place. From the data, a regression model was developed for predicting farmers{\textquoteright} intentions to control possum numbers. The model had a squared multiple regression co-efficient of 62\%. The individual regression coefficients all had F probabilities <0.001. It is apparent that possum control on farms is mainly undertaken to reduce the threat of bovine tuberculosis (Tb) in cattle. Farmers are also more likely to take steps to control possum numbers when they consider it will reduce pasture damage, contribute to an overall reduction in farm pests, and reduce damage to their fruit trees and gardens. Control is discouraged by risks of poisoning farm dogs and high costs. Policy agencies will need to work with scientists to provide the information landowners need to encourage their greater commitment to possum control even when the Tb threat has been reduced. }, issn = {1176-5283}, author = {Parminter TG and Wilson JA} } @conference {41442, title = {Structure and role of SIL in sheep genetic improvement in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {209-211}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {Sheep Improvement Ltd (SIL) has been developed to manage the national genetic database for the New Zealand sheep industry. Since its launch in 1999, SIL has gained acceptance as the provider of the industry standard sheep genetic analysis. As part of the greater industry, SIL has a key role to play in fostering the uptake of performance recording to maximise the rate of genetic improvement in the commercial flock, through improved ram breeding and selection decisions. Long-term benefits of genetic improvement are dependent on delivering scientifically advanced analysis to all members of an informed industry. This requires consistency of information, supplied at varying levels of complexity, but always in a simple, accurate and relevant form. SIL provides information in a flexible and easy to understand format, backed up by a strong focus on industry education. Continuous development focuses on delivering new outputs related to improved profitability, more accurate analysis, including major-gene effects as they become available, and greater flexibility at a computational level. Equally importantly, SIL will develop outputs to provide greater flexibility, relevance, ease of use and understanding by all users of genetic information.}, issn = {1176-5283}, author = {Cruickshank GJ} } @conference {41405, title = {Survival of in vitro-produced cattle embryos from embryo transfer to weaning}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {57-60}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {New reproductive technologies present both the beef and dairy industries of New Zealand with numerous opportunities. A key factor in the successful use of these technologies is the reproductive rate obtained from their use. MOET (multiple ovulation and embryo transfer) is a fairly well established procedure to achieve pregnancy by embryo transfer. As an alternative, harvesting of oocytes, in vitro fertilization, culture, and subsequent embryo transfer (IVP-ET), also has potential. The technology is still relatively new and pregnancy rates of 30\% have been reported. This is at least 10\% lower than that achieved with MOET. As part of another project, approximately 400 recipient cows, in each of three years, were subject to ET using fresh IVP embryos. Pregnancy rates to calving, per embryo transferred, averaged 40, 44 and 33\% in 1999, 2000 and 2001 respectively. Within years, average pregnancy rate varied from less than 20\% to over 50\% depending on recipient source (P<0.05), breed (P<0.01) and condition score (P<0.05). Once cows could be detected pregnant, at about 50 days after embryo transfer, they tended to stay pregnant through to calving. Neither embryo breed nor the type of oestrus-synchronizing device had a significant effect on pregnancy rate. }, issn = {1176-5283}, author = {Smeaton DC and McGowan LT and Scott ML and Tervit HR and Cameron CA} } @conference {41394, title = {Valuing our farm environment}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {11-13}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {Lloyd and Kathy McCallum farm 447 ha at Lochiel on the Central Southland Plains. The milking platforms consist of two units each of 147 ha and 152 ha, the remaining being run-offs. We milk 850 Freisan/ Jersey X cows through two herring bone sheds on adjoining farms. The milking platform has two supporting run-offs one leased and the other owned. We have always been in the top 5\% for production in the Southland area.}, issn = {1176-5283}, author = {McCallum L and McCallum K} } @conference {41436, title = {What is a better ram worth?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {187-189}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {This paper presents equations that can be used to quantify the differences in value to a commercial farmer among rams available for purchase from a single ram breeder. The same approach can be taken for a group of breeders for which across-flock genetic evaluation results are available. Separate equations are presented in detail for buyers of both dual-purpose and terminal sire rams. A working version of the terminal sire equation incorporates the difference in the terminal sire index value between two rams, the number of years, and the number of ewes per year, to which the ram is to be mated and the tailing percentage in the commercial flock as variables. A working version of the dual-purpose sire equation incorporates the same variables as the terminal sire equation, but with the percentage of the ram{\textquoteleft}s daughters to be kept as replacement ewes also added. }, issn = {1176-5283}, author = {Meikle A and Amer PR} } @conference {41446, title = {Wintering systems for weaners in Otago and Southland}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {229-232}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {Low winter temperatures, high rainfall and high incidences of poor draining soils in Southland combine to created potential problems with winter "pugging" and soiled pastures by red deer weaners. Four wintering options presently exist for weaners in this region; pasture grazing, winter brassica grazing, outdoor enclosures and indoor enclosures. While pasture wintering is still the most common system used, the other options are becoming increasingly popular to mitigate against pasture/soil damage. This review contrasts these various options, particularly with respect to outdoor and indoor enclosures, and highlights recommendations for successful adoption of these systems. }, issn = {1176-5283}, author = {Lawrence D} } @conference {41428, title = {Wool yellowing and pH within Merino and Romney fleeces}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {155-159}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {Fleece samples were taken from the back, side and belly of three adult ewes in one Merino flock and three adult ewes in one Romney flock in each of six regions of New Zealand (Waikato, Manawatu, Wairarapa, Marlborough, Canterbury, Otago). Each fleece was 12 months growth. These samples were used to compare factors associated with wool yellowing as measured by tristimulus (Y-Z) values. Neither the region of New Zealand where the sheep grazed nor the measured dimensional fleece characteristics, were related to fleece yellowing. The pH of an aqueous extract of greasy wool was strongly related (R2 = 0.93) to tristimulus (Y-Z) (base yellow) at shearing but less strongly related (R2 = 0.70) to tristimulus (Y-Z) after the sample had been incubated at 40{\textdegree}C and 100\% RH for 6 d. Merino samples had a lower tristimulus (Y-Z), both before and after incubation, at a particular pH than Romney samples. Back wool did not increase in yellowness as much during incubation as side or belly wool possibly on account of photo-oxidation following prolonged exposure to sunlight. These data indicate a close relationship between pH of a water soluble component of greasy wool and the extent of wool yellowing that was influenced by sheep breed and body site. }, issn = {1176-5283}, author = {Sumner RMW and Young SR and Upsdell MP} } @conference {41319, title = {Ammonia and urea utilisation in lambs infected with Trichostrongylus colubriformis and fed fresh lucerne (Medicago sativa)}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {77-80}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {The effect of a Trichostrongylus colubriformis infections on ammonia and urea fluxes across the mesenteric-drained viscera (MDV), portal-drained viscera (PDV), and liver was investigated using an arterio-venous preparation in lambs fed fresh lucerne (Medicago sativa). The lambs were infected with 6000 T. colubriformis L3 larvae per day for 6 days (n=5) or kept as parasite free controls (n=5). On day 48 of the experiment, the lambs were infused continuously for 8 hours with r-aminohippuric acid (688 mg/h) into the mesenteric vein in order to measure plasma flow across the MDV, PDV and liver. Blood was continuously collected from the mesenteric artery and vena cava for consecutive two hour periods throughout the infusion period and plasma was harvested. Plasma concentrations of ammonia and urea were unaffected by the presence of intestinal parasites. Ammonia fluxes across the MDV, PDV, and liver were similar between treatment groups. Urea fluxes were also similar between treatment groups with the exception of the PDV, which showed a net release of urea in the parasite group and a net uptake by the control group (P=0.03). This suggests that the presence of a sub-clinical T. colubriformis infection does not increase the demand on the lamb for amino acids for ureagenesis. }, issn = {1176-5283}, author = {Bermingham EN and Roy NC and Reynolds GW and Sinclair BR and Peters JS and Sutherland IA and Waghorn GC and Revell DK and McNabb WC} } @conference {41390, title = {Analgesia for velvet antler removal}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {372-375}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {This paper briefly reviews methods for analgesia of the velvet antler. Injection of 2\% lignocaine hydrochloride (L) provides the most rapid and repeatable analgesia when given as a "high" dose ring block (1 ml/cm pedicle circumference). A "low site" regional nerve block has a long latency and low repeatability while a "high site" regional block also has a long latency but gives more repeatable analgesia after 4 minutes. Comparison of the dynamics of the alternative local anaesthetics showed L to have a mean analgesia onset time of 31 seconds and duration of 88 minutes. Mepivacaine (M) had a similar onset time, but a duration of 270 minutes, while two formulations of bupivacaine (B) had onset times averaging 48 and 87 seconds, and duration 270 and 460 minutes, respectively. Combinations of L+M, L+B and M+B had onset times equivalent to the most rapidly-acting component and duration equivalent to the longest-acting component. Electronic analgesia provides insufficient and non-repeatable analgesia and its application is a noxious stimulus in itself. Compression bands are approved in yearling stags in New Zealand. The effectiveness and possible aversiveness of high pressure compression bands on adult stags is under investigation. Pain and its control after antler removal, are yet to be studied comprehensively. }, issn = {1176-5283}, author = {Wilson PR and Bartels MM and Stafford KJ and Mellor DJ} } @conference {41387, title = {Analgesics: what use are they in farm animals?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {359-362}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {

The use of analgesic drugs in veterinary practice is increasing, particularly in companion animals. However, farm animals often suffer from conditions (such as foot rot), or are subjected to operations (such as dehorning), which are likely to be painful. Assessment of pain in farm animals can present difficulties and analgesic drugs have not been investigated in any systematic way. Most assessment of analgesic drugs in ruminants has been carried out using experimental models of pain rather than clinical cases. Some indications for analgesics are obvious, such as castration and dehorning. Others are not so obvious, such as mastitis, which is very painful in women, and presumably in cows. Animals in pain are likely to be less productive and there is good evidence that chronic pain will change an animal{\textquoteleft}s metabolism adversely. Valid reasons for not using analgesics include cost and concerns about residues, which ultimately also means cost. There are several different classes of analgesics, with different attributes. Local anaesthetics are cheap, but short acting. Residues in food have not been an issue in the past, but concerns have been raised in Europe about some metabolites being carcinogenic. Morphine-type drugs are cheap, but less effective in ruminants than other species, are likely to cause residues in food and are strictly controlled by law. Adrenergic alpha-2 agonists are effective, but also cause sedation. Residues can be managed by relatively short withholding times. Probably the most effective analgesics for ruminants are the non-steroidal anti-inflammatory drugs, such as ketoprofen. These have long withholding times for meat, but zero for milk.

}, issn = {1176-5283}, author = {Chambers JP and Stafford KJ and Mellor DJ} } @conference {41336, title = {An attempt to suppress the rut- associated loss of live weight in stags by immunocastration}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {149-151}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Two trials were conducted to study the effectiveness of vaccination of stags against gonadotrophin-releasing hormone (GnRH) for minimising the deleterious effects of the rut on their live weight and body condition. In March 2000, mature red deer stags (n = 10) received a s.c. injection of 1.0 ml of vaccine (Improvac{\textregistered}) or saline solution (controls) and a second injection three weeks later. Liveweight loss in the 10 weeks following the initial injection was not affected by the treatment (mean loss 28.6 {\textpm} 4.0 kg and 28.1 {\textpm} 4.2 kg for vaccinated and control groups, respectively). Plasma testosterone concentration was lower (P<0.05) in the vaccinated stags but there was no effect on scrotal diameter. In the following year, stags (n = 10) were injected with 2.0 ml of the vaccine or saline on 18 January and 8 February. Mean liveweight loss in 21 weeks was similar for vaccinated and control groups (41.2 {\textpm} 8.2 kg and 38.8 {\textpm} 7.2 kg, respectively) and there was no treatment effect on the reduction in body condition score. Although vaccinated stags had a lower (P<0.05) mean plasma testosterone concentration than control stags, this effect can be entirely attributed to stags (3 out of 4) that had been vaccinated in the previous year{\textquoteright}s trial. It is concluded that vaccination of stags against GnRH does not overcome the loss in live weight which is associated with the rut in these animals. }, issn = {1176-5283}, author = {Barrell GK and Nicol AM and Keeley MJ} } @conference {41364, title = {Can forages match concentrate diets for dairy production?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {261-266}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {

Comparisons have been made between concentrate based total mixed rations (TMR) and grass dominant pasture for dairy production. Limitations to further improvement in cow performance have been indicated by the very high reticulo-rumen fill in New Zealand cows fed pasture, exceeding 22\% of live weight, relative to United States cows fed either TMR or forage diets. The importance of high concentrations of structural fibre in ryegrass dry matter, moisture content of fresh forages and the very rapid eating associated with high utilization of pasture on New Zealand dairy farms will limit increases in feed intake and cow performance. Responses to ryegrass supplementation with high quality forages have been summarised together with suggestions for future research and farming systems to improve performance and profitability of cows fed forage diets.

}, issn = {1176-5283}, author = {Waghorn GC} } @conference {41350, title = {Climate Change: The global problem requiring a global response}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {202-205}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {

The New Zealand Government has stated its intention to ratify the Kyoto Protocol to address climate change. This has set in train a period of intensive policy development to assess the implications, derive policy measures and establish the appropriate legislative framework to carry out these intentions. Agricultural emissions in New Zealand, and particularly ruminant emissions, place New Zealand in a unique position compared to other developed countries. Ruminant agriculture provides both a potential solution and a threat to New Zealand meeting its targets under the Kyoto Protocol. The Convenor of the Ministerial Group on Climate Change has indicated that research is an important element in seeking to reduce New Zealand\’s greenhouse gas (GHG) emissions from agriculture. Animal science has an important role to play. Animal science in New Zealand is at the cusp of a new and exciting era. Any advances that scientists can make in unravelling, and finding practical solutions to reducing nitrogen throughput and methane emissions, whilst maintaining or increasing animal productivity, will have significant economic value to New Zealand. The background to the Kyoto Protocol, the Government\’s response, and the opportunities provided to animal scientists, are discussed.

}, issn = {1176-5283}, author = {Rys GJ} } @conference {41372, title = {Computer simulation of Johne{\textquoteright}s disease in New Zealand cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {294-298}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {

Control options for Johne\’s disease (JD) are explored by computer simulation because intervention trials under field conditions would be too costly. The purpose of this review is to describe a simulation model developed in The Netherlands and adapted to dairy herds in Pennsylvania (USA). The paper consequently derives what information is required for the adaptation to New Zealand dairy herds and explains the methods by which that information is currently collected. The model \‘JohneSSim\’ simulates the within herd development of JD based on time related changes. Time intervals are six months. JD is transmitted vertically through the placenta or from dam to calf around calving through direct contact, colostrum, rest milk or bulk milk, infected pasture, or through contact with adult replacement stock from other herds. Control options include test-and-cull, measures to prevent the infection of calves, vaccination, and grouping of animals by age. The simulation suggested that, in The Netherlands as well as in Pennsylvania, progressively improving calf-hygiene with little reliance on test-and-culling would decrease the prevalence considerably and was economically feasible (average benefit-costs-ratio excluding extra labor = 1.58). Test-and-cull was not economical even if a test with 80\% sensitivity was available. Contract heifer rearing, colostrum management, and seasonal calving appear to be risk factors for transmission that have specific relevance for New Zealand dairy herds.

}, issn = {1176-5283}, author = {Soons R and Heuer C and Jackson R and Groenedaal H} } @conference {41359, title = {Concentrations of conjugated linoleic acid in milk from cows grazing pasture of fed a total mixed ration for an entire lactation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {240-241}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {

Conjugated linoleic acid (CLA) is a collective term for the range of conjugated isomers of linoleic acid (C182). These fatty acids occur naturally in milkfat and have proven anticarcinogenic properties in laboratory rodents (Ip et al., 1999). Additionally, the various isomers have other reputed benefits for human health such as enhanced bone mineralisation, antidiabetic effects, reduced atherosclerosis and immune system modulation (Whigham et al., 2000). Such potential benefits for human health have focussed international research on enhancing concentrations of CLA in milk and dairy products. Overseas data show that one way to increase the concentrations of CLA in milk is to change the diet of cows from a typical total mixed ration (TMR) to pasture (Kelly et al., 1998; White et al., 2001). This points to a potential competitive advantage for the New Zealand dairy industry, in which pasture is already almost the sole source of feed. Despite this there are no data confirming the beneficial effects of pasture for enhancing CLA under New Zealand grazing conditions. The experiment described here used an existing experiment to compare the concentrations of CLA in milk from cows fed TMR or grazing pasture for an entire lactation under New Zealand conditions.

}, issn = {1176-5283}, author = {Audlist MJ and Kay JK and Thomson NA and Napper AR and Kolver ES} } @conference {41373, title = {Control of Johne{\textquoteright}s disease in dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {299-302}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {

Control of Johne{\textquoteleft}s disease caused by Mycobacterium avium subspecies paratuberculosis (MAP) in dairy cattle has assumed significantly greater attention over recent years. The primary reasons are; possible increasing prevalence, an increase in the number of overseas control programmes, the continued scientific debate about the link with Crohn{\textquoteleft}s disease in humans, and the reported presence of MAP in commercial pasteurized milk sold in retail markets. Johne{\textquoteleft}s disease is a chronic wasting disease of ruminants worldwide. Accurate prevalence data does not exist for New Zealand. The best estimates available currently estimate the annual cost in New Zealand for dairy farmers to be between $3.8 million (based on 12\% herd infection) and $31.7 million annually. It is likely that with the current control technology available the cost of control would exceed the on farm benefits, and therefore significant market access issues will have to be the basis for implementing a national control programme. For New Zealand to achieve control it is essential that the current prevalence be established and an understanding of the epidemiology within the New Zealand farming system be developed. Unlike many other diseases current tests available for Johne{\textquoteleft}s disease have low sensitivity which results in any testing programme failing to detect significant numbers of infected animals. Current areas being examined include test methods, vaccine and management practice modification. Additionally the possibility of genetic selection for resistant animals may be possible with the molecular genetic capabilities that are currently being developed in the bovine.

}, issn = {1176-5283}, author = {Burton L and Voges H} } @conference {41371, title = {Is Crohn{\textquoteright}s Disease caused by M. avium subsp. Paratuberculosis?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {290-293}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {

Speculation that M. avium subsp. paratuberculosis (MAP), the infectious agent of Johne{\textquoteleft}s disease, might be involved in the aetiology of Crohn\’s Disease (CD) in humans was first voiced in 1913. No supportive evidence was obtained until the organism was identified in cultures from a small number of CD cases in the 1980{\textquoteleft}s. Evidence accumulated over the last 15 to 20 years has left the medical community somewhat polarised about the possible role of MAP in Crohn{\textquoteleft}s disease. Technological advances enabling more sensitive detection of bacteria or their components (e.g. PCR, immunohistochemistry), or immunological responses to them, have not clarified the fundamental question of whether an apparent association between the presence of MAP and CD lesions may have any causal significance. The basis for concluding that MAP has a causal role in the aetiology of CD is unconvincing.

}, issn = {1176-5283}, author = {Davies PR} } @conference {41353, title = {Dairy industry perspectives of methane emissions and production from cattle fed pasture or total mixed rations in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {213-218}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {

This paper examines the significance of ruminant methane emissions for the NZ dairy industry at a time when NZ is about to ratify the Kyoto Protocol. We consider factors for practical methane mitigation, and a broad based research strategy for the development of measures to reduce methane emissions. A key factor in the process is the integration of methane mitigation research into existing research programs. We were able to incorporate methane measurements into a trial evaluating the performance of two dairy cow genotypes fed contrasting diets. Overseas genotypes produced 8-11\% less methane, as a percentage of gross energy (GE) intake, compared to New Zealand genotypes and total mixed rations (TMR) resulted in similar energy losses to methane (\% of GE) as pasture.

}, issn = {1176-5283}, author = {Robertson LJ and Waghorn GC} } @conference {41321, title = {The dairy product value chain: new opportunities from a holistic approach?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {86-89}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {The value chain for dairy products extends from on-farm production, through manufacturing and distribution, to the final consumer. Using an integrated approach across the value chain, it is possible to produce products that better suit consumers{\textquoteright} needs or preferences and that return more value to the farmer using on-farm methods. This approach requires a change in mindset for the manufacturing industry, and can be successful only in an industry that is fully integrated from cowshed to consumer. Some examples are described in the context of the value chain, and set the framework for the following papers.}, issn = {1176-5283}, author = {Boland MJ} } @conference {41338, title = {Digestion kinetics of ryegrass}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {157-162}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Changes in ryegrass maturation, with accompanying decreases in nutritive value and feed intake, have significant consequences for the dairy industry. Thus digestion kinetics of ryegrass were measured in samples differing in both physiological age (days after cutting) and calendar date to form a database that can be used as a guide to calculate the extent and type of supplement needed to match nutrient supply with requirements of grazing dairy cattle. Ryegrass pasture was mown on 21 August, 11 September, and 21 September and samples of approximately 2 kg were harvested from those dates at 7-14 day intervals for chemical analyses by cutting to 5 cm above soil level. These samples were used for in sacco and in vitro incubations to determine rate of digestion and proteolysis. The principal finding was a rapid decline in crude protein content from about 22.5\% of DM harvested at 21 days to 7.2\% for that harvested after 67 days. These changes were associated with increases in the neutral detergent fibre (NDF) fraction of the DM (42.1\% to 56.3\%) and in lignin concentration (2.49\% to 3.07\%). Changes were more rapid in late-cut than early cut forages. The principal consequences of increased maturity were slower degradation rates of DM (k= 0.067 to 0.038/hour) and CP (k= 0.122 to 0.052/hour) and less degradation of crude protein to ammonia. This data can be used in conjunction with dairy cow models (e.g., CNCPS) to predict animal performance. }, issn = {1176-5283}, author = {Chaves AV and Waghorn GC and Brookes IM and Hedderley D} } @conference {41313, title = {Does an increase in lamb birth weight through mid-pregnancy shearing necessarily mean an increase in lamb survival rates to weaning?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {53-56}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Lambing percentages in New Zealand have risen over the past decade and will most likely continue to rise, while the price for lamb remains high in relation to wool. Any technique that can increase the birth weights of lightweight multiple-born lambs may increase survival rates to weaning. Mid-pregnancy shearing as a possible technique to increase lamb survival under commercial conditions was examined in the present study. Mid-pregnancy shearing was found to significantly (4.7 vs 5.1kg, P<0.05) increase the birth weights of twin-born lambs but had no effect on birth weight of singletons or triplet-born lambs. Both the magnitude of the response, and the fact that it did not occur in all birth ranks, are consistent with previous mid-pregnancy shearing studies. Mid-pregnancy shearing had no significant effect on lamb survival rates to weaning. To achieve an increase in survival rate to weaning through an increase in lamb birth weight alone, the lamb must be born within a birth weight survival range below optimum, and the increase in birth weight must be large enough to move a significant proportion of these lightweight lambs into a higher survival rate range. }, issn = {1176-5283}, author = {Kenyon PR and Morris ST and McCutcheon SN} } @conference {41356, title = {Does feeding sulla (Hedysarum coronarium) reduce methane emissions from dairy cows?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {227-230}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {

Most of New Zealand\’s methane is generated as a by-product of feed fermentation in the rumen of livestock and is released through the mouth and nose. An experiment conducted in late summer using Friesian and Jersey dairy cows investigated whether feeding sulla (Hedysarum coronarium), a condensed tannin (CT)-containing legume, reduced methane emissions without compromising milksolids production. Cows grazing sulla had higher intake (DMI; 13.1 vs. 10.7 kg DM/cow/d, P\<0.001) and milksolids production (1.07 vs. 0.81 kg MS/cow/d, P\<0.001) than cows grazing perennial ryegrass pasture. Total daily methane emissions were similar (253.9 vs. 260.0 g CH4 /cow/d, ns). However, cows fed sulla produced less methane production per unit DMI (19.5 vs. 24.6 g CH4 /kg DM, P\<0.05) and per unit milksolids yield (243.3 vs. 327.8 g CH4 /kg MS, P\<0.01) than those fed ryegrass due to the higher nutritive value of sulla compared with the ryegrass, and possibly the presence of CT. Further research will determine whether feeding alternative, high quality forages is a viable methane mitigation option for New Zealand dairy farm systems, but results of this study clearly indicate that CT-containing legumes, such as sulla, do effectively reduce methane emissions from dairy cows without compromising milksolids production.

}, issn = {1176-5283}, author = {Woodward SL and Waghorn GC and Lassey KR and Laboyrie PG} } @conference {41314, title = {Does mid-pregnancy shearing affect lamb fleece characteristics}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {57-60}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Mid-pregnancy shearing has been promoted as a technique to increase both lamb birth weight and survival in multiple-born lambs. Mid-pregnancy shearing has also been shown to increase dam wool quantity and quality and, in some instances, increase lamb growth rates until weaning. It has also been suggested that shearing of the dam during pregnancy results in a change in the lamb{\textquoteright}s fleece characteristics. The aim of this study was to further investigate the effect of dam shearing treatment on lamb fleece characteristics. Thirty-one singleton and 29 twin-born lambs were born to either mid-pregnancy shorn or unshorn Romney ewes. At 6 months of age the lambs were midside sampled (to allow measurement of staple length (SL), washing yield, loose wool bulk, colour and mean fibre diameter (MFD)). A skin biopsy was taken from the midside to measure the ratio of secondary to primary follicles. The lambs were shorn three weeks later and a fleeceweight was obtained. Lambs born to shorn dams had a higher MFD (32.9 vs. 31.3mm, P<0.05) and had slightly whiter wool (0.1 vs. 0.3, P=0.07) than their counterparts born to unshorn ewes but did not differ for yield, SL or bulk. The higher MFD found in the lambs born to shorn ewes was associated with a decrease in the number of secondary follicles (P<0.05) without a significant decrease in the number of primary fibres. There was a significant interaction (P=0.05) between birth rank and shearing treatment on fleeceweight such that twin-born lambs born to shorn dams tended to have heavier fleeces (by 170g) than those born to unshorn dams, this relationship was not observed in singleton lambs. This study suggests that for singleton lambs, mid-pregnancy shearing of the dam will have no appreciable effect on wool value. However in twin-born lambs an increase in fleece weight may offset any decreased value due to higher MFD. }, issn = {1176-5283}, author = {Sherlock RG and Kenyon PR and Morris ST} } @conference {41346, title = {Dynamic selection for sheep genetic improvement}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {188-190}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Dynamic selection is a process used in livestock improvement programmes to maximise genetic progress while constraining the long term rate of inbreeding. An optimisation algorithm identifies proportions of genes each selection candidate should contribute to the next generation. Application of dynamic selection procedures to select cull and replacement ewes, and then subsequently to select a ram team, was demonstrated using data from a Romney sheep breeder. When compared with selection based on an index of breeding values alone, dynamic selection of cull and replacement ewes reduced the accumulation of relatedness by approximately 85\% of the average annual accumulation from 1994 to 2000. To achieve this, approximately 33\% of the average annual genetic progress in average index value was sacrificed. Using dynamic selection to identify a ram team to be mated to selected ewes resulted in a saving in relatedness by an amount equal to the average annual accumulation from 1994 to 2000 with only a very modest drop in genetic progress of 9\% of the average annual genetic progress in average index value. This study has demonstrated that dynamic selection tools could, when practically applied to sheep breeding populations, provide a transparent and efficient means of managing the tradeoff between rate of genetic progress and rate of accumulation of relatedness. }, issn = {1176-5283}, author = {Amer PR and Jopson NB and McEwan JC} } @conference {41360, title = {Effect of a Total Mixed Ration diet on the concentration of amino acid-derived volatiles in milk}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {242-245}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {

The flavour chemistry of milk from Holstein-Friesian cows of two genotypes fed total mixed rations (TMR) or pasture has been compared over three years. Mean concentrations of selected milk aroma compounds, namely skatole, indole, dimethylsulphide, toluene, and of total p-cresol (determined after hydrolysis of conjugates) were significantly lower (10\% to 39\% of pasture treatment, P \< 0.01) in the milk from the TMR-fed cows. Mean milk non-protein nitrogen (NPN) and dietary crude protein content (CP) were lower (93\% and 67\% of pasture treatment respectively) for the TMR diet. These results are consistent with an origin for these aroma compounds in the degradation of dietary protein amino acids in the rumen. However, concentrations of total m-cresol, which is not thought to derive from dietary protein, were also lower in the milk from TMR-fed cows (19\% of pasture treatment). In addition, for the pasture treatment, the patterns of variation of concentrations of skatole, indole and p-cresol and NPN in milk and of dietary CP differed considerably between different periods within a dairy season. These findings indicate that factors additional to CP supply are important in the metabolism of these flavour compounds.

}, issn = {1176-5283}, author = {Lane GA and Fraser K and Kolver ES and Rowan DD and Allen JM and Mills OE and Abraham AS and Olney SD} } @conference {41309, title = {Effect of body condition at calving of milkfat composition of Friesian heifers during the first ten weeks of lactation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {38-41}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {The effects of live weight and body condition score (CS) at calving on milksolids production has been well documented. The effects of CS at calving on detailed composition of milk, the physical characteristics, or, product quality are largely unknown. Milkfat yield, fatty acid profile (FAP), solid fat content (SFC) of milkfat during the first 10 weeks of lactation were monitored for Friesian heifers with a pre-calving CS of 4.1 (LCS) or 5.2 (HCS). Once calved, all heifers were grazed as one herd and offered pasture ad libitum. Composition and characteristics of milkfat were determined at four, six, and 10 weeks postpartum. At four weeks postpartum the HCS heifers, produced 23\% more (P<0.001) milkfat, lost 59\% more (P<0.001) live weight and CS declined 30\% more (P<0.05) than did LCS heifers. Associated with these changes were compositional changes in milkfat. CS at calving had no effect on milkfat concentration. HCS heifers produced milkfat with lower concentrations (P<0.01) of de novo synthesised fatty acids (C4:0-C15:1) and higher (P<0.01) concentrations of preformed fatty acids. Concentration (mg/100 mg milkfat) of oleic acid (C18:1) was higher: 27.4\% c.f. 24.8\%, s.e.d. 0.94 (P<0.001) for HCS compared with LCS heifers. Milkfat from HCS heifers was softer, SFC at 5{\textdegree}C (55\% c.f. 59\%, s.e.d. 1.2, P<0.01) than from LCS heifers. Six weeks postpartum, the differences in FAP persisted but changes in live weight and CS were small compared with the first four weeks of lactation. Ten weeks post calving both groups were gaining live weight, but although differences (P<0.01) in live weight, CS, and daily milkfat yield persisted, no differences in FAP or SFC were found. These results show that differences in pre-calving live weight and CS cause differences in the composition and characteristics of milkfat. Milkfat from HCS heifers was more desirable (softer and higher in unsaturated fatty acids) than from LCS heifers. These differences disappeared once the two heifer groups were in positive energy balance by 10 weeks postpartum. }, issn = {1176-5283}, author = {Thomson NA and Bryant MO and Chand A and MacGibbon AKH and Chagas LM} } @conference {41357, title = {The effect of condensed-tannins in fresh Sulla (Hedysarum coronarium) on the net flux of fatty acids across the mammary gland and their secretion in the milk of lactating ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {231-235}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {

Twelve sheep were surgically prepared with catheters in the mesenteric artery and mammary vein and a transonic flow probe around the pudendal artery to quantify the effect of condensed-tannins (CTs) on net mammary flux of fatty acids (FAs) and their secretion in milk. Two weeks later (Day 0), sheep were fed fresh Sulla (1500 g DM/d), which contains medium to high concentration of CTs (43.7 g CTs/kg DM). Six ewes were orally drenched (four times/d) with polyethylene glycol (160 g/d in water) to remove the effects of CTs; the remaining ewes received water. On Day 28, the mammary plasma flow and net flux of most FAs were similar between treatments. Arterial supply of C23:0, C18:2, C18:3, C20:1 and C22:5 to the mammary gland was increased (P\<0.10) with CTs. The increase for C18:2 and C18:3 was concomittant with increased (P\<0.10) concentrations in milk. No effect of CTs on total fat concentration and yield in milk was observed. Conclusions from this study indicate that CTs in Sulla increased the milk concentration of C18:2 and C18:3 by increasing arterial supply of these FAs to the mammary gland.

}, issn = {1176-5283}, author = {Roy NC and Knight TW and Reynolds GW and Deighton MH and Death AF and Sinclair BR and Peters JS and McNabb WC} } @conference {41318, title = {The effect of cysteine and glutamine supplementation on sheep infected with Trichostrongylus colubriformis}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {72-76}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {This indoor study investigated the effect of direct daily abomasal supplementation of both cysteine (cys; 1g) and glutamine (gln; 5g) on a 12-week subclinical Trichostronglylus colubriformis trickle infection in lambs. Parasite infection increased the total number of leucocytes and eosinophils in peripheral circulation, nitrogen excreted in faeces and urine (P<=0.01) and plasma total protein concentration (P<0.05). Infection also reduced liveweight gain and plasma albumin concentration (both P<0.001), but did not alter feed intake. Supplementation increased nitrogen retention (P<0.05), tended to increase phe (P=0.056) and cys (P=0.097) flux, reduced the number of circulating eosinophils (P<0.001) and changed the pattern of faecal egg counts (P<=0.05), with no effect on final nematode counts. This experiment showed supplementation with two non-essential amino acids alone can elicit changes in the response of sheep to internal parasite infection.}, issn = {1176-5283}, author = {Hoskin SO and Lobley GE and Coop RL and Jackson F} } @conference {41340, title = {The effect of endophyte alkaloids on diet selection by sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {167-170}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Sheep have a strong preference for clover in summer. One explanation for this may be the avoidance of alkaloids such as lolitrem B, ergovaline and peramine that are produced at that time of the year by endophytic fungi in ryegrass. We tested this hypothesis by exposing groups of three sheep to three food items (ryegrass with wild-type endophyte (E+), ryegrass with no endophyte (E-), and white clover (CL)), in December and in February. Each food was offered singly and in pairs, and time spent grazing on each food, short-term dry matter (DM) intake rate, and preference was measured. In February, sheep given E+ or E- ryegrass alone, grazed for 400 mins/day, compared with 370 mins/day when given a choice between them (P=0.15, SEM=14). The time spent grazing on the E+/E- choice was comprised of 280 mins/day on E- and 90 mins/day on E+ indicating a strong preference for E-. When offered ryegrass and white clover, the total grazing time (335 mins/day), and the grazing time on clover (285 mins/day) and on ryegrass (50 mins/day), were similar for E+/CL and E-/CL. Short-term dry matter intake rate of grass (3.4 g DM/min), and the strong preference for clover in this study, were unaffected by the presence of endophyte. We conclude that while sheep detect endophyte alkaloids, they avoid eating them only when doing so does not reduce daily intake or change the proportion of grass and clover in their diet. }, issn = {1176-5283}, author = {Cosgrove GP and Anderson CB and Phillot M and Nyfeler D and Hume DE and Parsons AJ and Lane GA} } @conference {41334, title = {Effect of grazing undrenched weaner deer on chicory or perennial ryegrass/white clover pasture on gastrointestinal nemotode and lungworm viability}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {143-144}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Internal parasites can reduce animal performance (Moss \& Vlassoff, 1993) and lungworm has been known to cause death in young deer (Mackintosh et al., 1984). Increasing numbers of drench resistant parasite populations being found on farms throughout New Zealand (Sangster, 1999) and pressure from consumers to reduce anthelmintic input for fear of residues in pastoral-based food products (Williams, 1997), signifies a need to find alternative methods of internal parasite control. Hoskin et al. (1999) found that undrenched weaner deer grazed on chicory did not have impaired growth rates and faecal egg counts were lower compared to similar animals grazed on perennial ryegrass/white clover pastures. This suggests that chicory has the potential to be used in farming systems to reduce the negative impact of internal parasites. This study looked at the viability of internal parasites that had travelled through the digestive tracts of deer grazing chicory (Cichorium intybus) or perennial ryegrass (Lolium perenne)/white clover (Trifolium repens)- dominant pasture. The hatching ability of gastrointestinal nematode eggs, the development of gastrointestinal nematode and lungworm larvae and the motility of L1 lungworm larvae were measured. The study also determined the effect of adding condensed tannins (CT), extracted from chicory, to rumen and abomasal fluid on L1 lungworm larval migration. CT are a group of phenolic secondary plant compounds found in chicory at concentrations of approximately, 4.2g/kgDM (Terrill et al., 1992). }, issn = {1176-5283}, author = {Schreurs NM and Molan AL and Lopez-Villalobos N and Barry TN and McNabb WC} } @conference {41303, title = {Effect of transport stress on somatic cell counts in dairy goats}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {16-18}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Somatic Cell Counts (SCC) are commonly used as an indirect measure of prevalence of bacterial infection and of milk quality in dairy cattle. However, interpretation of SCC in dairy goats is more complex due to a higher basal SCC and the fact that SCC appear to be influenced by a number of factors other than bacterial infection. Increased SCC is associated with bacterial infection of the udder in goats (Dulin et al., 1983; Ryan et al., 1993; Poutrel et al., 1997). However, SCC in goats also increases with age (Dulin et al., 1983), increases as lactation progresses (Dulin et al., 1983; Kalogridou-Vassiliadou et al., 1992; Wilson et al., 1995), varies among breeds (Sung et al., 1999) and increases as milk production declines (Zeng \& Escobar, 1994; Pizzillo et al., 1994). Stressors such as change in nutrition, kidding, oestrus and vaccination have also been suggested as causes of increased SCC in goats (Lerondelle et al., 1992; Aleandri et al., 1994; Pizzillo et al., 1994; Zeng et al., 1997). The stress response includes both corticosteroid release from the adrenal cortex in response to adrenocorticotrophic hormone (ACTH) and adrenal medulla release of the catecholamines adrenaline and noradrenaline (Tyrrell et al., 1991). Injection of dairy cattle with exogenous ACTH results in an elevation in circulating leukocyte counts but no change in the SCC (Paape et al., 1973, 1975). However, transportation is likely to release both corticosteroids and catecholamines and has been used to examine various physiological responses in goats (Sanhouri et al., 1989; Greenwood \& Shutt, 1992) {\textellipsis} }, issn = {1176-5283}, author = {McDougall S and Anniss FM and Cullum AA} } @conference {41323, title = {Effect of udder health on milk}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {95-99}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Mastitis is an inflammation of the udder tissue, normally arising from a bacterial infection. The effects of mastitis on the processing properties of milk have been widely researched over the past 40 years. This paper summarises the main effects of udder health on raw milk composition and its processing properties, reviews the progress made to date by the New Zealand dairy industry with regard to reducing the impact of mastitis on milk processing, and highlights continuing avenues of enquiry.}, issn = {1176-5283}, author = {Lacy-Hulbert SJ and Auldist MJ} } @conference {41312, title = {The effects of mid-pregnancy nutrition and shearing on ewe body reserves and foetal growth}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {49-52}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {In an experiment replicated over three years, ewes were individually fed concentrate diets containing two levels of protein (12 and 18\%) at either maintenance or 1.5 x maintenance from days 35 to 74 of pregnancy, and then at an allowance of approximately 2.0 kgDM/head/day on pasture until parturition. Half of the ewes within each treatment were shorn on day 74. Ewes were CT scanned to measure body composition at days 35, 74, 115 and 140 of pregnancy. Neither protein nor energy level fed during mid-pregnancy had any significant effects on conceptus growth, birth weight or lamb skeletal measurements. Shearing resulted in changes in ewe body composition as well as an increase of 0.36 kg (P<0.01) in lamb birth weights. Lambs from the shorn ewes were 14 mm longer in length (P<0.05) but 8 mm shorter in height (P<0.05) than those from unshorn ewes. Shorn ewes lost 1.3 kg more body fat (P<0.001) than their unshorn contemporaries over the second half of pregnancy. Unshorn ewes lost 0.74 kg of carcass lean over this period, while the shorn ewes gained 0.22 kg (P<0.001). The results show that ewes can be fed maintenance during mid-pregnancy if this allows good quality feed reserves to be built up in front of them for the third trimester. Mid-pregnancy shearing is likely to increase lamb survival in multiple born lambs through higher birth weights.}, issn = {1176-5283}, author = {Jopson NB and Davis GH and Farquhar PA and Bain WE} } @conference {41382, title = {Effects of pregnancy on the fever response of sheep to a Gram-negative pyrogen}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {337-339}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {

Ewes commonly display a reduction of immunity to gastrointestinal parasites during the periparturient period, so it is possible that other components of immunity change at this time. To determine whether the reported absence of fever in full-term-pregnant ewes occurs in a breed farmed commercially in New Zealand, 12 pregnant and 9 non-pregnant Coopworth ewes were treated with injections of Escherichia coli lipopolysaccharide (LPS) at five-weekly intervals for 3.5 months. An initial dose-response study, conducted in a separate group of ewes, determined that a dose of 200 ng/kg LPS induced fever (\≥ 0.7\°C increase in rectal temperature) in our sheep. Rectal temperature and plasma glucose concentration were monitored at the time of LPS injection and 4 h later. The magnitudes of both the mean increase in rectal temperature (range 0.4 to 2.1\°C) and the mean reduction of plasma glucose concentration (range 2.9 to 17.7 mg/dl) appeared to vary throughout the study but they were not affected by pregnancy, nor was there any difference in these parameters between the two groups of sheep at the periparturient period. However, there was a reduction in the incidence of fever generated by LPS in the post-lambing period, lactating ewes appearing to have smaller increases in rectal temperature (mean increase 0.4\°C, n = 11) than their non-lactating counterparts (mean increase 0.8\°C, n = 8). We conclude that at least part of the immune response to LPS, i.e., fever and the reduction of plasma glucose concentration, is maintained in our Coopworth ewes at full-term of pregnancy.

}, issn = {1176-5283}, author = {Breen GP and Barrell GK} } @conference {41317, title = {The effects of sheep breed on the defects pinhole and raised rib}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {69-71}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {The effect of sheep breed and wool type on the incidence of the skin defects "pinhole" and "raised rib" was investigated. Six breeds/crosses were used - pure Romneys and Suffolk x Romney, Dorset x Romney, East Friesian x Romney, Texel x Romney and Merino x Romney crosses. Skins were recovered at slaughter and processed to dyed crust leather, then scored numerically for the severity and extent of pinhole and graded into the "Run" (best quality), "Pinhole", and "Thirds" grades. The presence or absence of raised rib on the skins was noted. Wool bulk and fibre diameter were measured. Skins from Romneys had the least pinhole and Merino crosses the most. Skins from Texel, Dorset and East Friesian crosses were also significantly more likely to be downgraded due to pinhole than those from Romneys. Within-breed differences in the level of pinhole were due to wool bulk differences, with a higher wool bulk correlated with more pinhole. Merino-cross skins were much more likely than the skins from pure-bred Romneys or the other crosses to have raised rib. Texel-Romney-cross skins were more likely than pure-bred Romney skins to have raised rib. There was no difference between the mean wool fibre diameter for ribby and non-ribby skins, but the ribby skins had a significantly higher wool bulk. }, issn = {1176-5283}, author = {Cooper SM} } @conference {41310, title = {Effects of time-of-calving on dairy production: a farmlet study}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {42-43}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Most dairy cows in New Zealand are calved just prior to spring in order to maximise pasture utilisation. This practice is associated with marked irregularities in the volume and composition of milk supplied to factories, which is a major limitation of seasonally-calving, pasture-based dairying systems. The need to accommodate peak milk flow means that manufacturing plants are underutilised for most of the season. Further, changes to milk composition can make it difficult to manufacture dairy products of high quality during some parts of the season, which necessitates the storage of product to meet out-of-season demand. Such irregularities are caused by a number of factors, including nutritional factors associated with the changing quality and availability of pasture, and physiological and hormonal factors associated with the stage of lactation of the cows (Auldist et al., 1997). One way of manipulating the lactation curve of the cows may, therefore, be to adjust the time of the year at which calving occurs. A previous study in New Zealand showed that autumn calving herds could be as profitable as spring calving herds (Garcia et al., 1998). In that study, nutritional demands were matched with pasture availability by adjusting stocking rate and feeding varying amounts of pasture and maize silage when required. A premium for winter milk was also applied. The current study was designed to investigate the effects of calving at four different times of the year on milk production in farmlet systems which were otherwise similar in stocking rate and other farm management variables. }, issn = {1176-5283}, author = {Audlist MJ and MacDonald KA and Thomson NA and Coulter M and Lancaster JAS and Penno JW} } @conference {41304, title = {Efficacy of antibiotic treatment at drying off in curing existing infections and preventing new infections in dairy goats}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {19-21}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Infusion of antibiotics into the udder at the end of the lactating period ({\textquotedblleft}dry cow therapy{\textquotedblright}; DCT) is an essential control measure for bovine mastitis (Smith et al., 1967). Dry cow therapy eliminates existing intramammary infections (IMI) and reduces the incidence of new infections over the dry period with a resultant reduced prevalence of IMI at the commencement of the subsequent lactation (Smith et al., 1967; Harmon et al., 1986). The cure rate of existing infections after DCT has been reported as between 60-90\% (Pankey et al., 1982; Sol et al., 1994; Browning et al., 1990; Williamson et al., 1995). Dry cow therapy reduces the new IMI rate by approximately 50\% (Browning et al., 1994; Williamson et al., 1995). Infusion of antibiotics at the end of lactation in dairy goats ({\textquotedblleft}dry-goat therapy{\textquotedblright}; DGT) has been reported to cure between 66\% and 100\% of existing IMI (Fox et al., 1992; Poutrel \& de Cremoux, 1995; Poutrel et al., 1997). However, the efficacy of DGT in reducing the new infection rate over the dry period has not been examined. The aim of this trial was to assess the efficacy of intramammary antibiotic treatment of dairy goats at the end of lactation in curing existing mammary gland infections and reducing the incidence of new infections over the dry period and early in the subsequent lactation. }, issn = {1176-5283}, author = {Anniss FM and McDougall S} } @conference {41302, title = {Endogenous synthesis and enhancement of conjugated linolieic acid in pasture-fed dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {12-15}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {The primary conjugated linoleic acid (CLA) isomer in milkfat, cis-9, trans-11 CLA, is a proven anticarcinogen in rodents and can be derived directly from ruminal biohydrogenation of linoleic acid. The major fatty acid in pasture, however, is alpha-linolenic acid; the biohydrogenation of which does not produce cis-9, trans-11 CLA as an intermediate. Therefore, in grazing cows, cis-9, trans-11 CLA must be produced by other sources, possibly via D9-desaturation of trans-11 vaccenic acid (TVA), a biohydrogenation product of both alpha-linolenic acid and linoleic acid. Studies were conducted to i) determine the importance of endogenous synthesis of cis-9, trans-11 CLA in pasture-fed cows and ii) increase the level of cis-9, trans-11 CLA. The first study involved abomasal infusion of sterculic oil (SO) to inhibit the activity of the D9-desaturase enzyme. Abomasal infusion of SO decreased the concentration of cis-9, trans-11 CLA in milk fat by 71\% (P<0.01; 3.6 c.f. 12.1 {\textpm} 0.15 mg/g fatty acid). The presence of cis-9, C 1 0:1, cis-9, C12:1 and cis-9, C14:1 in the milk fat of cows following SO treatment indicated D 9-desaturase was not completely inhibited. Using the changes in these fatty acids to evaluate the extent of D9-desaturase inhibition with SO treatment, an estimated 87-100\% of cis-9, trans-11 CLA in milk fat was of endogenous origin. In the second study, sunflower oil at 4\% DMI/cow/day invoked a 38\% increase (P<0.01) in milk fat TVA (61.3 c.f. 44.4 {\textpm} 0.51 mg/g fatty acid) and a subsequent 28\% increase (P<0.01) in cis-9, trans-11 CLA concentrations compared to control (28.5 c.f. 22.3 {\textpm} 0.19 mg/g fatty acid). Results demonstrate that endogenous synthesis is the major source of cis-9, trans-11 CLA in pasture-fed dairy cows and levels can be enhanced by increasing the supply of the ruminally-derived precursor, TVA. }, issn = {1176-5283}, author = {Kay JK and Mackle TR and Auldist MJ and Thomson NA and Bauman DE} } @conference {41337, title = {An evaluation of sulla (Hedysarum coronarium) with pasture, white clover and lucerne for lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {152-156}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Pasture-based diets restrict animal performance, due to limitations in voluntary feed intake and release of nutrients during digestion failing to meet nutrient requirements. Opportunities for improving the efficiency of pasture utilisation include the addition of a soluble carbohydrate source to enable an improved capture of ammonia by rumen bacteria, or the inclusion of condensed tannins (CT) to reduce protein degradation. A feed evaluation trial was conducted at AgResearch Grasslands to investigate the ability of sulla, a forage containing high concentrations of soluble carbohydrate and CT, to complement pasture and legume species. Fifty-six weaned ram lambs were allocated to seven diets: pasture (80\% ryegrass and 20\% white clover), white clover, lucerne, sulla, and 50:50 mixtures (DM basis) of pasture:sulla, white clover:sulla and lucerne:sulla. Lambs fed sulla, white clover, white clover:sulla and lucerne:sulla had the most rapid daily gains (256-263 g/day) while lambs fed pasture gained 105 g/day, respectively. Wool growth was influenced by diet. Sulla added to pasture, white clover and lucerne diets significantly reduced rumen ammonia concentrations and acetate:propionate ratios in lambs. Lamb performance can be improved by combining sulla with pasture and lucerne, and rumen parameters can be used to explain animal performance differences. }, issn = {1176-5283}, author = {Burke JL and Waghorn GC and Brookes IM} } @conference {41315, title = {Factors associated with yellowing within Romney}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {61-64}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Four two-year-old Romney ewes born in the Waikato and four two-year-old Romney ewes born in Canterbury that had been grazed together in the Waikato for 12 months, were used to investigate aspects of yellowing in wool samples grown on the mid-back, mid-side and mid-belly. Two sheep in each sub-group had a history of having a relatively high and two sheep a relatively low, propensity for their fleece to turn yellow during the previous year. Dimensional fibre characteristics, with the exception of staple length, were not significantly different between body sites, between the propensity groups or between birth farm groups. Wool was shorter on the belly than on the other two sites. Incubating greasy sub-samples of each fleece at 40{\textdegree}C and 100\% relative humidity for 6 d induced a curvilinear increase in yellowness with the CIE Y - Z value approaching an asymptote. A significant amount of the variation in yellowing was explained by the concentration of K, Ca and possibly Na, elements secreted in the suint. These data suggest that the propensity of a fleece to turn yellow is not related to fleece architecture or the elemental composition of the fibres, but may have a physiological basis possibly related to sweating behaviour. }, issn = {1176-5283}, author = {Sumner RMW} } @conference {41363, title = {Factors influencing inducing decision-making in dairy cows: a case study of scientists{\textquoteright} and producers{\textquoteright} views}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {257-260}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {

The purpose of this investigation was to identify and describe the on-farm decision-making context of dairy farmers when they decide to induce dairy cows. A social researcher facilitated the meetings between a Waikato dairy farmer and two collaborating groups, to gather and record data regarding on-farm induced parturition decision-making over a year. These sessions took place at times when decision-making would impact most on induction. Cognitive mapping was used to capture the context within which decision-making in connection with inducing dairy cows took place. The following main conclusions were made: a long term perspective of induction is required; the induction decision-maker does not have control over all the factors that influence induction but could foresee and manage several of them by appropriately using applicable records; cow condition plays a critical role; the focus farmer had a much more straightforward view than scientists of induction and viewed it on a time line; decision-making with regards to inducing cows is a continuous process and capturing it requires a systems perspective; the interactions between different factors that influence induction become more apparent and more obvious to participants when these factors were made visual through the cognitive mapping technique.

}, issn = {1176-5283}, author = {Botha CAJ and Verkerk GA} } @conference {41316, title = {Genes with major effects on wool traits detected in Finn cross sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {65-68}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Two Finn sires with short wool staple lengths (Finn-S1 91 mm, Finn-S2 107 mm) and two with long staple lengths (Finn-L1 147 mm, Finn-L2 133 mm) were joined with Dorset Down (staple length 37-120 mm) and Romney (staple length 105-166 mm) ewes. Over two years, each ram sired between 83 and 210 progeny. Wool characteristics of progeny were measured at 6 months of age. For all sire groups, distributions of fibre diameter, fibre curvature, fibre medullation and clean fleece weight were not significantly different from single normal distributions. Similarly the distributions of fibre diameter coefficient of variation (FDCV), staple-crimp frequency and staple length for progeny of Finn-S1, Finn-S2 and Finn-L1 were close to unimodal. In contrast, the same three traits for progeny of Finn-L2 fitted two normal distributions. For all three traits, the mean value of one of the distributions of Finn-L2 progeny was similar to the means of the other three sire groups, while the mean of the second distribution was 41\% greater (FDCV), 65\% greater (staple length) or 67\% less (crimp frequency) than that of the first. These results suggest the presence of a gene or genes with major effects on fibre traits. }, issn = {1176-5283}, author = {Bray AR and O{\textquoteright}Connell D and Saville DJ} } @conference {41344, title = {Genetic engineering and the public: Attitudes, beliefs, ethics and cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {179-182}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {A postal survey (n = 1682, margin of error 3\%) used a hypothetical milk product with medical benefits produced by genetically engineered (GE) cows as a stimulus to examine New Zealanders{\textquoteleft} support and attitudes towards GE for food and medicine. Beliefs about proposed benefits of GE, ethical issues associated with GE, and ethical perceptions about the status and treatment of cows were canvassed. Ten times as many respondents totally opposed GE food as totally supported it. Medical applications (15.6\%) received significantly more total support than GE food production (3.4\%). A majority of respondents were prepared to support GE under some circumstances (medicine 61.8\%, food 51.7\%) - implying their need for case-by-case analysis. Respondents disagreed GE will: cure the world{\textquoteleft}s major diseases, solve the world{\textquoteleft}s food problems, improve the quality of animal lives, be environmentally benign, or that the spread of GE organisms can be controlled. GE did not fit with respondents{\textquoteright} cultural and spiritual beliefs or basic principles. Although agreeing the instrumental use of cows by humans was acceptable, respondents strongly disagreed genetic modification of cows for human benefit was acceptable. Consistent significant differences were found between males and females on all the above issues. }, issn = {1176-5283}, author = {Small BH and Peddersen JA and Wilson JA and Parminter TG} } @conference {41322, title = {Genetic opportunities to improve milk value in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {90-94}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {The value of milk in New Zealand can be improved by altering its composition by genetic means (crossbreeding, selection, and biotechnology). Breed changes and crossbreeding influence the value of milk, but the choice of breed is usually dominated by attributes other than milk composition. Responses to within-breed selection are influenced by the emphasis placed on milk components relative to other animal attributes. The relative economic emphasis among the traits in the objective, and the genetic and environmental relationships between measured performance attributes will influence the rate of progress in milk quality, milk value and farm profit. Transgenic modification of the bovine genome offers the possibility of quantum shifts in milk characteristics but requires further research, education and testing in order to gain consumer acceptance. The manufacture of high-value dairy products for specific markets will likely require the segregation of milks from different farms. The long-term nature of genetic improvement dictates that today{\textquoteleft}s vision shared by producers, processors and AB companies must be in concert with future needs of consumers if real opportunities are to be realised. }, issn = {1176-5283}, author = {Lopez-Villalobos N and Garrick DJ and Holmes CW} } @conference {41367, title = {Genetics modification to create novel high quality forages}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {278-281}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {

Genetic improvements in forage quality can lead to improvements in animal performance. We outline two approaches aimed at generating high quality forages that increase the energy available to the ruminant. These include the heterologous expression of fructan biosynthesis genes in the leaf to produce high molecular weight soluble carbohydrate and the modification of the expression pattern of endogenous triacylglyceride biosynthesis genes to produce triacylglycerides in the leaf. In vitro experiments demonstrated the potential of the rumen to digest fructans with either b(2-6) or b(2-1) linkages, furthermore both in vitro and in vivo experiments showed that fructan reduced the concentration of NH3 in the rumen. We discuss the advantages of raising the lipid content of forage and the ramifications of expressing triacylglcyeride biosynthesis genes in the leaf. The expression of other genes that modify the quality of the fatty acids within triacylgycerol are also discussed briefly.

}, issn = {1176-5283}, author = {Roberts NJ and Hancock KR and Woodfield DR} } @conference {41326, title = {Giving consumers more reasons to drink milk}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {108-110}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {The options confronting consumers when choosing a milk product continue to expand. This is driven from the recognition that consumers have different needs and that milk is perhaps the best nutritional raw material that can be used to deliver a range of enhanced nutrition and health benefits. Products that target the needs of specific age groups, health concerns, or greater affordability, all give consumers greater justification for consuming milk. Similarly, the ever-increasing range of product formats, flavours and new products containing milk that are supported by emotive marketing campaigns will ensure that consumers continue to have plenty of justification for having that extra glass.}, issn = {1176-5283}, author = {Haylock SJ} } @conference {41339, title = {Growing grass and clover separately allows animals to sustain a high nutrient intake}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {163-166}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {White clover has high nutritive value but the proportion in mixed pasture and therefore the diet, is often low. Offering sheep ryegrass and clover growing side-by-side, for short periods, increases the proportion of clover in the diet and daily intake compared to a mixed pasture. This experiment tested whether sheep offered ryegrass and clover side-by-side could sustain a high proportion of clover in their diet and a high daily intake, compared with sheep grazing ryegrass alone, clover alone and ryegrass and white clover growing as a mixed sward. Forty-eight dry, non-pregnant Romney ewes (56 {\textpm} 1.8kg live weight) were randomly allocated to four replicates (two spatial x two temporal) of each treatment (n=3) for 12 days. Average grazing time was 292 {\textpm} 16.2 min/day and did not differ significantly among treatments. Short-term intake rate on clover (5.0 g/min) was higher than ryegrass (3.5 g/min) (P=0.02). As a result, clover dominant diets supported higher daily intake (1.36 kg/d for clover alone vs. 1.08 kg/d for ryegrass alone). Sheep sustained a diet of 70\% clover and 30\% ryegrass, showing that predominance of clover in the diet was not a result of novelty. This improved daily intake would provide significant benefit to animal production systems and can be achieved simply by growing grass and clover separately. }, issn = {1176-5283}, author = {Marotti DM and Cosgrove GP and Chapman DF and Parsons AJ and Egan AR and Anderson CB} } @conference {41354, title = {Implementation of environmental regulations on-farm}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {219-224}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {

A case study of the consultative process concerning water clarity in Lake Taupo was used to identify the key elements required to reach consensus between land-owners, users and regulatory authorities. These elements included: the identification of all stakeholders; impacts at the farm level where individual behaviour change must occur; the scientific validity of data used and the decision support models available to assess biological and economic impacts. The importance of the consultative {\textquoteleft}process{\textquoteleft} itself and the need for sufficient time for this process to occur were other key elements. The Lake Taupo case study was then compared with the larger scale issue of greenhouse gas emissions (GHG) from New Zealand agriculture. We concluded that a much greater level of scientific uncertainty existed for the effect of GHG emissions on climate change than for Lake Taupo water clarity. This fact, coupled with the potentially much greater economic impacts on agriculture and individual farmers helped explain farmer reluctance to accept proposed solutions. Findings from the Lake Taupo study suggest the way forward in the GHG emission debate requires a major improvement in the underpinning science and a clearer understanding of the implications of GHG emission control at the farm scale. Mitigation options must consider both physical and financial inputs and outputs. The consultative process must involve farmers at policy, economic and science levels and be long enough to cover all issues.

}, issn = {1176-5283}, author = {Clark DA and Lambert MG} } @conference {41379, title = {Improved nutritional quality of animal products through manipulations of trace element and calcium status}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {325-329}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {

Research on the requirements and metabolism of trace elements in grazing livestock is revealing new ways in which the nutritional status of people might be improved. Our understanding of how to manage the mineral status of cattle and sheep can create additional impact through enhancing the quality and value of milk and meat. For example, by optimising the familiar selenium and iodine supplementation strategies used to prevent deficiencies and maintain animal mineral requirements, we can tailor the element content of the resulting animal products. Simple Se and I supplementation produces commensurate increases in milk and meat, but the concentrations of calcium and iron are not so easily manipulated, so other smarter strategies are called for. For these four nutritionally essential elements, maximum concentration and bioavailability to humans is affected by age of animal, stage of lactation, plus element chemical form and distribution among the milk and meat fractions.

}, issn = {1176-5283}, author = {Knowles SO and Lee J} } @conference {41365, title = {Improving animal performance using forage-based diets}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {267-272}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {

New Zealand livestock systems are based on ryegrass dominant pastures, but they are unable to maximise animal production. Limitations of ryegrass-based pastures are reviewed, and opportunities for using alternative forage species to complement pasture and improve animal production are discussed. Ryegrass pastures have low dry matter contents and high fibre concentrations which restrict feed intake so animal energy requirements are often not met. High crude protein (CP) concentrations in spring and rapid proteolysis in the rumen produces excess ammonia which must be excreted, whereas summer pastures contain insufficient CP. Chicory, red clover, lotus species, sulla, lucerne and maize silage are examples of forages that can complement ryegrass to improve animal performance. More information is needed to define digestion and fermentation of fresh forages in the rumen, but in vitro and in sacco techniques have been used to evaluate these parameters for grasses, legumes, herbs and silages. This information with feed composition data will be used in computer simulations to predict forage mixtures able to complement pasture at different times of the year. The challenge will be to complement the changing ryegrass pastures with other forages to improve animal welfare, productivity and profit.

}, issn = {1176-5283}, author = {Burke JL and Waghorn GC and Chaves AV} } @conference {41381, title = {Incidence and perceptions of cryptorchid lambs in 2000}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {334-336}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {

A telephone survey of 400 randomly selected sheep farmers was undertaken to determine the incidence of ram, cryptorchid, and wether lambs in the New Zealand lamb flock in 2000. Respondents were asked why they choose to produce rams, cryptorchids or wethers and how willing they would be to change. The percentage (+/-5\%) of male lambs left entire and made cryptorchids was similar at 39\% and 41\% respectively with the remaining 20\% wethers. The primary reasons why farmers produced cryptorchids was to achieve good lamb growth rates and lean carcasses without having fertile male lambs. Published research reports support the perception of leanness relative to wether lambs but indicate that carcass weights are similar to those of ram and wether lambs and that some cryptorchids may be fertile. Secondary reasons given for producing cryptorchids were that they were cleaner and easier managed than ram lambs. Although the production of cryptorchids has declined in recent years, 71\% of the farmers who currently produce them have a preference for this method and indicated unwillingness to change from this practice.

}, issn = {1176-5283}, author = {Tarbotton IS and Bray AR and Wilson JA} } @conference {41306, title = {Incidence of mastitis among cows of different genogtypes in differing nutritional environments}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {24-29}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Over three seasons (1998, 1999 and 2000) groups of Holstein-Friesian cows of New Zealand (NZ) or overseas (OS) origin were monitored for mastitis when managed in two contrasting systems. Cows were fed either on pasture or total mixed ration (TMR) with cows on TMR confined to small loafing paddocks or a concrete feedpad. All quarters were sampled for bacteriology at calving, at dry off, in mid and late lactation and when clinical mastitis was detected. Individual cow somatic cell counts (SCC) were determined weekly throughout lactation. In 1998, there was no difference in incidence of clinical mastitis but in later seasons, cows on TMR experienced significantly more clinical, and sub-clinical mastitis, than cows on pasture, probably reflecting differences in bacterial challenge within the environment. Genotype differences were less evident compared to dietary effects. Compared to NZ cows, OS cows experienced more sub-clinical infections in 1998 and more clinical infections in 1999 whilst in 2000, genotype effects were confounded by diet. Seasonal SCC was higher for OS cows in 1999 and 2000, reflecting differences in incidence of sub-clinical mastitis among treatment groups. Despite the strong influence of environment on mastitis incidence, genotype differences were detectable between NZ and OS cows. }, issn = {1176-5283}, author = {Lacy-Hulbert SJ and Kolver ES and Williamson JH and Napper AR} } @conference {41305, title = {Increased milk lactic acid concentration is an early indicator of mastitis}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {22-23}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {The cost of mastitis to the dairy industry in NZ is substantial, with economic losses accruing from antibiotic costs, acute and chronic milk yield losses and reduced longevity of susceptible cows. Early detection and treatment of mastitis is a critical factor in reducing the severity of the infection and tissue damage within the udder (Douglas et al., 1997). However, increases in labour productivity are reducing contact time with cows, making early detection of mastitis increasingly difficult. In particular, the development of robotic milking equipment has highlighted the need for remote detection of mastitis. Apart from visual examination of fore-milk, somatic cell count (SCC) is used as the standard marker of milk quality. An increase in bulk milk SCC or a high SCC at herd test is used to diagnose new infections. However, one of the most widely used methods for cow-side or automated in-line testing for mastitis is the detection of changes in electrical conductivity of milk. This approach has several problems, not least of which is the limited accuracy of the method (see Woolford et al., 1998) and the relatively high cost of sensors (claws). The following study was undertaken as part of a screen of a number of potential markers in milk which could be used to indicate mastitis {\textellipsis} }, issn = {1176-5283}, author = {Farr VC and Prosser CG and Nicholas GD and Lee J and Hart AL and Davis SR} } @conference {41335, title = {Induced cryptorchidism no solution to the rut}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {145-148}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Two experiments were made to determine if induced cryptorchidism (short-scrotum) would modify behaviour and reduce liveweight loss during the rut without affecting subsequent velvet production. In the first experiment, groups (n = 10) of entire and induced cryptorchid mixed-age stags were used in a behaviour study in consecutive years. In mid-January, stags in the cryptorchid group were sedated with xylazine, and their scrotum shortened as much as possible (two thirds of the length) by the application of two standard lamb castration rings. Behavioural observations made during the rut showed significant (P< 0.05) reductions in the incidence of roaring, chasing and pacing in the cryptorchid group. In a larger scale experiment on six commercial properties, the live weight and condition score change over the rut, and subsequent velvet production was compared on 100 entire and a similar number of cryptorchid stags. Average liveweight loss during the rut (Feb-June) was 17 kg with no significant difference between entire and cryptorchid stags. There was no difference in mean live weight of the two groups the following Sept/Oct and the average velvet weight was 2.48 and 2.41 kg for the entire and cryptorchid stags respectively (P>0.05). Although induced cryptorchidism influenced stag behaviour during the rut, this was not reflected in reduced live weight or condition score loss during this period. }, issn = {1176-5283}, author = {Nicol AM and Keeley MJ} } @conference {41300, title = {Influence of milk cytokines on mammary production of nitric oxide}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {3-6}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Cytokines such as interferon-gamma (IFN-g) can stimulate the production of nitric oxide (NO) from mammary epithelial cells, which in turn may play a role in intramammary defence of the mammary gland. In this study, comparisons were made with the production of IFN-g stimulated NO from Comma-D cells (murine mammary epithelial cell line) and explants of mammary tissue collected from both pregnant (day 12-14 of gestation) and lactating (day 12-14 postpartum) rats. Response to IFN-g was measured as the production of nitrate and nitrite (NOx) in the culture medium. Comma-D cells and explants of mammary tissue from pregnant and lactating rats responded to treatment with 250 U/ml IFN-g with an increase in NOx of 5231, 300 and 373\% respectively. The response to IFN-y was lower (P<0.001) in explants than in Comma-D cells. Inclusion of nitric oxide synthase (NOS) inhibitors aminoguanidine (100 mM) and Nw-nitro-L-arginine (1 mM) in the culture medium reduced NOx production by the Comma-D cells to 31 and 19\% of stimulated activity respectively. This suggests that Comma-D cells are a good model for investigating effects of cytokines on mammary epithelial cell production of NO, and may also provide a useful means of screening other milk bioactives for their potential role in intramammary defence. }, issn = {1176-5283}, author = {Turner S-A and MacKenzie DDS and Prosser CG} } @conference {41328, title = {An innovative farm system combining automated milking with grazing}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {115-119}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {The harvesting of raw milk for the New Zealand dairy industry is a labour intensive process. Technology to completely automate the milk-harvesting process has been developed in Europe and is operating on an increasing number of commercial farms in several countries. A research programme has been established at Dexcel to develop innovative pasture-based farm systems utilising existing automated milking technology. A new farm layout was designed and implemented on a 10 ha farmlet. The land was radially subdivided into eight paddocks leading to a central collection area. A 200-m two-way race extended between the collection area and a small waiting yard adjoining a Fullwood Merlin automated milking system (AMS). Water was only available in the central collection area, the holding yard and as cows exited the AMS. Cows had access to the AMS for 24h/day where they received a maximum of 2kg concentrate/ 24h. A herd of 41 mixed-age cows was milked in the farm system. Data for a 14-day period in October when cows had settled into the system were analysed. Cows voluntarily visited the AMS 2.7 times/24h and were milked 2.3 times/24h. Visits were distributed over 24h with the lowest number of visits occurring between 0330 and 0600. Cows demonstrated remarkable adaptability in a distributed AMS and there appears to be considerable potential for AMS within New Zealand{\textquoteright}s pasture-based farming system.}, issn = {1176-5283}, author = {Jago J and Copeman P and Bright K and McLean D and Ohnstad I and Woolford M} } @conference {41374, title = {Johne{\textquoteright}s disease in deer - prospects for control}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {303-306}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {

This paper summarises current knowledge of Johne{\textquoteleft}s disease (JD) in farmed deer in New Zealand and discusses prevention and control options. JD in deer is caused by \"bovine strains\" and \"ovine strains\" of Mycobacterium avium subsp. paratuberculosis. Two clinical syndromes are recognised; sporadic cases in mixed age deer and serious outbreaks, affecting up to 15\% of groups, in 8 to 15 month old deer. Over 300 deer farms are known to be infected and the number is increasing. Studies have shown that the gel diffusion test is the most reliable test for confirming JD in clinically affected deer. However, none of the currently available serological or cell-mediated immunological tests is sufficiently sensitive or specific for detecting subclinical paratuberculosis in deer. Farms free of JD should prevent its introduction. Control options on infected deer farms are limited to management options: culling affected stock, culling test-positive animals or depopulation and restocking after 2 years. Vaccination may be the most cost-effective long term control option if a suitable vaccine can be developed. A voluntary market assurance programme for deer farms has been proposed, but implementation depends on the benefits to farmers and on the national deer farm JD prevalence being low enough to warrant it.

}, issn = {1176-5283}, author = {Mackintosh CG} } @conference {41368, title = {Johne{\textquoteright}s Disease - Why Johne{\textquoteright}s disease is so difficult to control}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {282-283}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {

Johne{\textquoteleft}s disease caused by infection with Mycobacterium avium subspecies paratuberculosis affects New Zealand cattle, sheep, goats and deer. The disease is difficult to control because of the long incubation period, the long survival of the organism in the environment, shedding by apparently healthy but infected animals and the unreliability of diagnostic tests to detect subclinical or even clinical disease. A brief contrast with the approach to control in New Zealand and Australia is made

}, issn = {1176-5283}, author = {West DM} } @conference {41349, title = {Karyotyping as an important screen for suitable donor cells to generate cloned and cloned transgenic animals by nuclear transfer}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {199-201}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {

Modern reproductive technologies are using cultured cells for the reconstruction of embryos. Cultured cells, however, can acquire abnormal karyotypes and, if not diagnosed, will compromise correct embryonic development. This manuscript briefly describes the evaluation of the karyotypes of cells used either for nuclear transfer or blastocyst aggregation to reconstruct embryos. Tetraploidy was found to be the major deviation from the normal diploid set of chromosomes. Most of the primary bovine and ovine cell lines derived from adult skin tissue contained cells with an abnormal chromosome number (75\%). The percentage of abnormal cells was in the range of 0-55\%. A higher proportion of clonally derived foetal cell lines had a normal karyotype (74\%). Although two abnormal cell lines of this class contained only tetraploid cells, which is most likely due to the clonal nature of their derivation. In contrast, all clonal mouse embryonic stem-cell lines (four) were karyotypically normal.

}, issn = {1176-5283}, author = {Olifent M and Miller AL and Beaton A and L{\textquoteright}Huillier P and Wells DN and Laible G} } @conference {41355, title = {Lactoferrin concentration is increased in milk from cows milked once daily}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {225-226}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {

Lactoferrin is a component of milk whey, valuable for its properties as an iron-binding, bacteriostatic and anti-bacterial protein. Commonly, lactoferrin concentrations are high in colostrum and in late-lactation milk (Nonnecke \& Smith, 1984). In particular, the lactoferrin content of mammary secretion is markedly increased during mammary involution when expression of the lactoferrin gene is initiated in milk-engorged, secretory alveoli (Molenaar et al., 1996). A feature of once-daily milking (OAD) is the accelerated regression of the udder that leads to an increased rate of decline in milk yield as lactation progresses (Carruthers et al., 1993). This accelerated regression and attenuation of lactation is particularly notable in some cows, although others appear relatively unaffected. In addition, there are changes in milk composition commensurate with changes that normally occur at drying-off. This suggests that milk lactoferrin concentration could be enhanced during OAD. Milk lactoferrin content has not been measured previously in cows in which milking frequency has been changed. Eight cows (mixed breeds) in mid-lactation, grazing rye-grass/white clover pasture at No. 1 Dairy, Dexcel (Ruakura) were used in this study. They were milked twice daily (TAD) from parturition and underwent a period of three days of OAD beginning at day 123\±4 of lactation, on average. Mean milk SCC before treatment was 178\±53 x 103 cells/ml. Milk samples were taken before, during and after OAD and assayed for lactoferrin using an ELISA method (Bethyl Laboratories, Montgomery, Texas, USA.) Milk yield and composition were also recorded.

}, issn = {1176-5283}, author = {Farr VC and Prosser CG and Clark DA and Tong M and Cooper CV and Willix-Payne D and Davis SR} } @conference {41383, title = {Livestock Improvement Corporation Lecture: Animal Welfare: ethics, economics and productivity}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {340-347}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {

Ethics is about what people think, productivity relates to what useful output animals can provide, while economics is the framework within which these human and technical values get sorted out in food production and consumption. This paper offers a deliberately non-specialist overview of these issues as they relate to farm animal welfare, in an attempt to show a social science approach to what is otherwise regarded as a matter predominantly of animal science. It discusses how ethical positions concerning animal welfare link to consumer preferences, which are the driving force of economic activity, and suggests that in this context science may be informative, but not necessarily influential in determining how livestock production methods are determined. The essential conflict in livestock farming between human benefit and the animals\’ wellbeing is analysed using a simple model reflecting the choices associated with different preference patterns in society. The simplistic argument that high welfare standards will raise food prices is shown to be technically correct, but the likely magnitudes are very minor. In relation to trade in livestock products, whether in domestic or international markets, the issue of animal welfare standards has ultimately to be considered in the context of satisfying consumer preferences; it should not be overly confused by emphasis on comparative costs or agricultural protection.

}, issn = {1176-5283}, author = {McInerney JP} } @conference {41341, title = {Liveweight gain of lambs grazing {\textquoteright}Ceres Tonic{\textquoteright} plantain (Plantago lanceolata) or perennial ryegrass (Lolium perenne)}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {171-173}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {The pasture herb plantain has been successfully adapted to pastoral agriculture and, while it is readily accepted by livestock, there is little information on corresponding animal performance of regularly grazed leafy plantain forage. Liveweight gain and trace element status of lambs grazing pure plantain (Plantago lanceolata) swards and high endophyte perennial ryegrass (Lolium perenne) pastures was evaluated for 85 days during summer (December - March) under irrigated conditions. Liveweight gain was significantly (P<0.01) higher for lambs grazing plantain (222 g/head /day) than ryegrass swards (135 g/head/day) when both were offered at an allowance of 2.5kg DM/head/day. Despite a lower stocking rate on plantain swards, lamb liveweight gain expressed on a per-hectare basis tended to be greater for the plantain treatment (6.0 kg/ha/day) than for the ryegrass treatment (5.1 kg /ha/day) although this did not reach statistical significance. Lambs grazing pure plantain swards had significantly (P<0.01) higher liver copper (2250 vs 715 ({\textmu}mol/ kg fresh wt) and higher liver selenium (671 vs 380 (nmol/kg fresh wt) concentrations but similar vitamin B12 (620 vs 571 nmol/kg fresh wt) concentration compared with ryegrass-fed lambs. These results indicate that well managed plantain is able to support relatively high rates of liveweight gain in lambs through summer and elevate liver copper and selenium concentrations and, therefore, could make a significant contribution to pastures in lamb finishing systems.}, issn = {1176-5283}, author = {Moorehead AJE and Judson HG and Stewart AV} } @conference {41330, title = {Managing dairy calves using continuous stocking and sward surface height - a review}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {124-127}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {The objectives of this review are (i) to examine the role of continuous stocking management in grazing experiments and on farm; (ii) to discuss the measurement of sward surface height; (iii) and to present experimental liveweight gain data obtained from calves continuously stocked from weaning to nine months of age. Sward height can be used as a guide in cultivar evaluations to maintain equal sward conditions between plots and treatments using put-and-take and continuous stocking management. Continuous stocking management can also be used on farm to achieve the recommended liveweight targets for dairy calves. However, further research is needed to determine the optimum sward height for calves. Weaned Friesian dairy heifers continuously stocked from November 2000 to April 2001 at Dexcel, Hamilton, and grazed to a mean sward height of 5 cm, steadily gained 0.8 kg/day, reaching a final mean of live weight of 226 kg at 9 months of age. The average stocking rate over this period was 7.1 calves/ha and the total liveweight gain was 822 kg/ha. These calves achieved the recommended liveweight targets set for replacement dairy heifers. }, issn = {1176-5283}, author = {Bluett SJ and MacDonald KA} } @conference {41327, title = {Milk and consumer health: review of the evidence for a relationship between the consumption of beta-casein A1 with heart disease and insulin-dependent diabetes mellitus}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {111-114}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {New developments in dairy foods, identifying health benefits from "functional foods" have a counterpart in claims of adverse health effects from milk components. A prime example is the present highly publicised claim of adverse effects of "A1 milk". Although there is some evidence that the consumption of beta-casein A1 may have an effect on the development of insulin dependent diabetes, other studies in this area have produced results that are inconsistent with such a claim. Some studies indicate that the removal of beta-casein A1 from the diet would have no influence on the incidence of insulin dependent diabetes. Epidemiological evidence for a relationship between the consumption of milk (and of beta-casein A1) with heart disease appears to have been a serendipitous correlation that occurred in the past perhaps due to a common underlying factor) but now no longer holds. Elimination of beta-casein A1 from the diet will have no effect on the mortality rate due to heart disease. Evidence to support claims that the consumption of the A1 variant of the milk protein beta-casein is a causative factor in heart disease and insulin dependent diabetes is therefore not sufficient to promote a change in consumer milk consumption away from dairy products containing beta-casein A1. }, issn = {1176-5283}, author = {Hill JP and Crawford RA and Boland MJ} } @conference {41301, title = {Modelling dairy production in different regions of New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {7-11}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {A whole-farm model is being developed at Dexcel for researchers to simulate whole-farm system trials. Climate and management information is entered and the model utilises published sub-models for pasture growth and cow metabolism. The model predicts pasture and animal production. A test of the model{\textquoteright}s validity in different New Zealand regions using climate, land and management information particular to each region was undertaken. Regions selected were; Northland, Taranaki, Canterbury and Southland. The model predicted 92-129\% of per cow milk production and, while it followed observed pasture growth patterns, there was a tendency to over-predict annual growth (5-57\%) especially during spring-early summer and more notably in the Northland region. Annual pasture growth in Southland was consistently under-predicted by approximately 20\%. This variation is likely due in part to differences in pasture species, soil types and the method of collecting pasture data, influencing how well the model predicted growth. Using specific climate data and management information, the model successfully predicted dairy production in most regions of New Zealand. }, issn = {1176-5283}, author = {Lile JA and Bright KP and Palliser CC and Prewer WE and Wastney ME} } @conference {41307, title = {Monitoring onset of puberty in three genetic strains of Holstein-Friesian dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {30-33}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Live weight and age at puberty were determined in three strains of Holstein-Friesian dairy cattle in each of two consecutive years. The strains were overseas-origin high-breeding-worth genetics (OS), New Zealand-origin high-breeding-worth genetics (NZH), and New Zealand-origin low-breeding-worth genetics (NZL), similar to the New Zealand dairy cow of the 1970s. Onset of puberty was monitored by weekly measurement of progesterone in a total of 271 heifers. Animals were considered to have attained puberty when plasma progesterone concentrations were greater than 2ng/ml in two out of three consecutive samples. Live weight at puberty differed between the strains (OS > NZH > NZL; P<0.05) but not between years. Age at puberty was affected by strain in Year 1 (OS > NZH > NZL; P<0.01), but not in Year 2. The greater live weight required to attain puberty in OS genotype animals must be recognized in target live weights for rearing of heifers. }, issn = {1176-5283}, author = {McNaughton LR and Morgan SR and Gore P and Verkerk GA and Holmes CW and Parkinson TJ} } @conference {41386, title = {Monitoring pain in animals using behaviour}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {355-358}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {The behaviour of an animal is used to identify and evaluate pain. However, simple active behaviours may not be sufficient for these purposes. Several different scales and experimental protocols have been developed for use in clinical and experimental circumstances. The use of control groups and different analgesic treatments has allowed the identification of behaviours related to particular painful stimuli. Pain threshold monitoring, self-administered analgesic trials and choice tests are furthering our understanding of an animal{\textquoteleft}s response to painful stimuli and procedures. These protocols combined with physiological, immunological and production indices are allowing for a better understanding of the effects of painful stimuli on animals. However, the interpretation of behaviour remains difficult and evaluating pain in a non-human species remains controversial. }, issn = {1176-5283}, author = {Stafford KJ and Mellor DJ} } @conference {41320, title = {Moving towards low-chemical farming with sheep and cattle: potential of a breeding approach}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {81-85}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {On livestock farms in New Zealand, some farmers are changing their sheep, beef cattle or dairy cattle enterprises towards specialisation in low-chemical or organic systems. A vital part of the animal{\textquoteright}s ability to perform under these systems is having the disease resistance genes available (or some other means to cope), as well as having the production and quality traits. In practice, animals are likely to be under a number of disease challenges at any one time, so breeders must concentrate their genetic selection practices on the most important health problems. Other (non genetic) means may also be critical in helping to protect the animal. This paper reviews the New Zealand evidence for genetic differences in resistance to various important diseases or metabolic stresses in sheep and cattle, and shows that genetic selection could be applied successfully if required. The paper also discusses some of the challenges in realising the goal of low chemical farming, such as finding a source of rams, bulls or semen. The diseases/stresses that are covered are: in sheep, nematode parasites, dags, fly strike, facial eczema (FE) and ryegrass staggers (RGS); in dairy cattle, mastitis, bloat, FE, RGS, nematode parasites and hypomagnesaemia; in beef cattle, RGS, nematode parasites and hypomagnesaemia. Some breed differences are mentioned, but at present the main New Zealand evidence of genetic variation is derived from heritability estimates. In sheep, average heritability estimates are: nematode parasites in lambs, 0.23 (repeatability 0.30); dags, 0.20 (repeatability 0.4); fly strike, 0.26 (Australian data); FE, 0.45; and RGS, up to 0.17, depending on the challenge level (repeatability 0.28). Corresponding heritability estimates in cattle are: clinical mastitis 0.06 (or somatic cell count 0.09); bloat 0.19 (repeatability 0.45); FE 0.56; RGS no published estimate; nematode parasites in calves 0.32; hypomagnesaemia 0.15. The simple mean of heritability estimates for 10 traits in sheep and/or cattle was 0.26 (0.28 excluding the outlier, mastitis, at 0.06), suggesting that responses should be achieved if directional selection is applied after performance or progeny testing. Knowing the genetic correlations among these disease traits is also important, because of the multiple disease challenges likely, but few of these correlations have yet been documented. Opportunities for ranking sires using the principles of Group Breeding Schemes or Sire Reference Schemes are discussed. }, issn = {1176-5283}, author = {Morris CA and Mackay AD} } @conference {41366, title = {New opportunities to improve forage- based production systems}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {273-277}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {

Pasture based grazing systems in New Zealand provide many benefits such as low costs of production but there are also limitations to current high stocking rate systems. These include inconsistent quality and composition of pasture and therefore animal diet. The requirements for high production and tolerance to frequent grazing limit the number of species which can be successfully grown. The rate of productivity improvement has declined in recent years and new methods of management are needed to increase production and meet changing market requirements. Altering methods of forage presentation has been shown to improve production of milk and meat from pasture by allowing animals to achieve a high daily intake of desirable species such as clover. Further new evidence of the capacity of animals to regulate their intake toward goals other than maximizing daily dry matter intake is presented. It is argued that new opportunities for increasing grassland productivity will need to consider the behavioural responses of animals grazing pasture.

}, issn = {1176-5283}, author = {Marotti DM and Chapman DF and Cosgrove GP and Parsons AJ and Egan AR} } @conference {41352, title = {Nitrous oxide, it{\textquoteright}s formation and place in farm green house gas balances}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {211-212}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {

Nitrous oxide is a troublesome greenhouse gas for New Zealand\’s agricultural sector to deal with. It is formed by a naturally occurring soil process that is fundamental to the global nitrogen cycle. Quantities emitted are very small in a productive sense but very significant in New Zealand\’s greenhouse gas inventory. Increasing protein production from land carries an associated risk of increasing N O emission because increased inputs of N are usually required. Attention 2 to the detail of whole system N cycling and greenhouse gas balances is therefore necessary if the challenge of increasing population and food demand is to be met without incurring hidden costs from atmospheric change.

}, issn = {1176-5283}, author = {Carran RA} } @conference {41324, title = {On-farm management to modify milkfat composition - a review of experiments undertaken at Dexcel to produce a spreadable butter directly from the cow}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {100-103}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {For many years it has been known from overseas studies that the composition and physical characteristics of milkfat are influenced by diet. The feeding of oilseeds had been shown to reduce the concentration in milkfat of short- and medium-chain-length fatty acids and to increase the concentration of long-chain unsaturated fatty acids. It was also reported that these changes resulted in softer milkfat and butter with improved spreadability at low temperatures. With this knowledge, a six-year collaborative research programme between the New Zealand Dairy Research Institute and Dexcel was undertaken to investigate the economic feasibility of producing a spreadable butter directly from the cow. The programme investigated the influence of each component in pastoral dairying that may possibly influence milkfat composition. These were: pasture, (location, defoliation interval, and species effects) on pasture lipid composition, grazed pasture effects (species and grazing rotation), supplementary feed effects (ruminally and non-ruminally protected oilseeds), frequency of feeding, and milking management. Following the study of each component the various components will be combined to develop a total farm management system to achieve the programme{\textquoteright}s goals. The goal of producing a spreadable butter directly from the cow has been achieved, but the programme has yet to develop a profitable farm system to produce the product under existing returns for milksolids.}, issn = {1176-5283}, author = {Thomson NA and Auldist MJ and Kay JK and MacGibbon AKH and Murphy JJ} } @conference {41331, title = {Organic beef in Japan - is there any room for New Zealand?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {128-132}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {In September 2001, an incident of mad cow disease (bovine spongiform encephalopathy) occurred in Japan. Japanese people now seek improved safety of beef meat and organic beef might fulfil part of this requirement. In this study, interviews were held with owners of a pasture-based beef production farm on the island of Hokkaido in Japan, which is widely recognized among the Japanese consumers as a {\textquoteleft}healthy and ecological{\textquoteleft}. The farming system is pasture-based, raising Hereford, Angus and crossbreeds, rather than the traditional Japanese Black breed. It is necessary to use grain-based concentrate feed when the animals are being finished. These feeds are fully imported, non-genetically modified, and {\textquoteleft}post harvest free feed (PHF){\textquoteleft}. Feeding imported organic grains to cattle for fattening is contrary to the Codex organic regulations settled in 2001. Therefore, it would appear difficult to achieve domestic organic beef meat production in Japan. There are opportunities for New Zealand beef exporters to expand their market in Japan. To achieve this expansion, there are two major issues to address. Firstly, intensive market promotion to the Japanese consumer will be necessary using New Zealand{\textquoteleft}s "clean and green" image and pasture-based finishing systems. Secondly, research work is necessary to develop special beef commodities which fit the Japanese consumer{\textquoteleft}s taste. }, issn = {1176-5283}, author = {Ozawa T and Lopez-Villalobos N and Blair HT} } @conference {41384, title = {Pain - Definition and Physiology}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {348-350}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {

Pain is defined as an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage. For a stimulus to be painful, it must be perceived consciously and found to be unpleasant. To describe how pain is transmitted from the site of stimulation to the parts of the brain responsible for conscious awareness, the term nociception is used. A nociceptive stimulus is one which will be felt as painful if and when it reaches the conscious parts of the brain. Nociceptors (pain receptors) are located throughout the body. Some are specific for pain whilst others are sensitive to things (like hot or cold) which may or may not be painful depending on the intensity. Two kinds of pain are transmitted to the central nervous system. The first is pin-prick pain. This is mild, specific to an area and is transmitted rapidly. The second is true pain. This can be severe, is only poorly localised and is transmitted to the central nervous system slowly. Pin-prick pain is the sensory arm of a valuable protective mechanism which alerts the animal to the presence of things which may cause injury. True pain can affect the function and psychological state of the whole animal and is a significant welfare issue if it is severe or prolonged. The first step in dealing with pain in animals is to recognise it. Animals are not able to communicate verbally and so cannot describe their feelings. In order to assess pain, we are forced to make assumptions about how the animal is feeling from its behaviour or physical responses. For example, if a cow is lame, it may be reluctant to walk, lame on the painful leg when it must walk, and show physiological changes in its nervous and endocrine systems. If the pain is prolonged or severe, the animal may become depressed, lose weight and show reduced productivity. Because the animal cannot say \"my leg hurts\", people working with animals have a responsibility to look out for signs of pain and to investigate their underlying cause.

}, issn = {1176-5283}, author = {Johnson CB} } @conference {41388, title = {Pain - its effects on immune function and growth in animal}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {363-367}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Pain, in both animals and humans, can induce wide-ranging biological consequences. In farmed livestock, two of the most important of these consequences are the potential impacts of pain on immune function and growth. In humans, the subjective experience of pain is correlated with decreases in immunocompetence and increases in the subsequent incidence of illness. In animals, procedures that can be readily assumed to be painful, and which produce behavioural and physiological stress responses, can cause immunosuppression and reductions in feed intake. Although transient pain may temporarily enhance immune function, chronic pain is immunosuppressive. The deleterious effects of pain on animal growth appear linked to the inflammatory response that accompanies tissue injury and to the direct impact of pain on feeding behaviour. The pro-inflammatory cytokines, (interleukin-1, interleukin-6 and tumour necrosis factor alpha) contribute to tissue catabolism, and act directly at the central nervous system to induce anorexia and lethargy. Although these behavioural and metabolic responses to painful conditions are adaptive in the short term, allowing the animal to rest its injury and mobilise body reserves to aid healing, ongoing pain responses have obvious negative consequences for animal productivity. Therefore, both animal welfare and productivity considerations suggest that the relief of any ongoing pain, as well as of acute pain, is important. }, issn = {1176-5283}, author = {Fisher AD} } @conference {41362, title = {Pasture versus total mixed ration during the periparturient period}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {252-256}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {

The effect of diet and genotype on metabolic indicators of energy status in the periparturient cow were investigated. Fifty-six dairy cows of two different genotypes (Overseas Holstein-Friesian (OSHF) and New Zealand Holstein-Friesian (NZHF)) were randomly allocated to two dietary regimens. Half of each genotype group received a pasture/pasture silage diet pre-calving and a pasture diet post-calving, while the other half received a total mixed ration (TMR) pre- and post-calving. Compared with NZHF, OSHF had higher concentrations of plasma non-esterified fatty acids (NEFA; P\<0.05) and glutamic acid dehydrogenase (GDH; P=0.09), an indicator of liver fat infiltration, 30 d post-calving. Genotype did not affect the concentration of either b-hydroxybutyrate (BHBA) or glucose in plasma. Cows grazing pasture pre-calving had greater (P\<0.05) BHBA concentrations, but plasma NEFA concentration and liveweight loss during the first 30 days of lactation were not different. In summary, a pre-calving TMR did not appear to improve the metabolic energy status of the cow pre-calving. These results suggest that provided sufficient nutrients are supplied in the diet, the homeorhetic mechanisms within the cow allow adaption to very different diets. This implies that an all-forage diet pre-calving is sufficient for dairy cows fed forage post-calving.

}, issn = {1176-5283}, author = {Roche JR and Kolver ES and Napper AR} } @conference {41385, title = {Physiological indices of pain-induced distress}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {351-354}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {

To date, most assessments of the pain and distress caused by dehorning of calves and castration plus tail docking of lambs have employed changes in plasma cortisol concentrations. Although this approach can aid selection of the most appropriate methods in animal welfare terms, the use of cortisol as the sole physiological index allows conclusions to be drawn only about those features of acute responses to treatment which are reflected in plasma cortisol concentrations. Accordingly, in addition to the well-established cortisol responses to these treatments, that last hours, we now report on adrenaline responses that last minutes, and noradrenaline responses with an intermediate duration are described. Blood pressure, heart rate, adrenocorticotropic hormone and cortisol responses to ring castration plus tail docking of lambs are described, and their relative sensitivity as indices of low-grade pain as the acute responses to treatment wane are considered.

}, issn = {1176-5283}, author = {Mellor DJ and Stafford KJ} } @conference {41377, title = {Practical considerations for diagnosis and management of Cu status of deer}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {315-318}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {

Accurate diagnosis and appropriate management are essential for effective maintenance of an adequate copper (Cu) status of farmed deer. Deer with liver and serum concentrations below 60 \µmol/kg fresh tissue and 5 \µmol/L, respectively, are at risk of clinical disease or reduced growth rate. Deer with adequate serum Cu may have low liver Cu concentrations, but those with low serum Cu usually have low liver Cu concentrations. No sex differences in tissue Cu concentrations have been reported. Tissue Cu concentrations fluctuate seasonally, being lowest in late winter-early spring, and commonly with greater reduction from autumn to spring in adults than in younger deer. There is insufficient known about the Cu metabolism of deer to enable a prediction of future Cu status to be made. Analysis of forage is warranted as an aid to establish the underlying cause of deficiency and to assist management decisions. Oral Cu oxide wire particles and injectable Cu/EDTA are licensed animal remedies for Cu supplementation in deer. Treatment frequency depends on tissue concentrations, dietary factors, production goals and nutritional management. Recent research shows high rates of Cu sulphate application to pastures and grazing chicory can also elevate deer tissue Cu concentrations. Monitoring the efficacy of supplementation using changes in liver Cu concentrations is essential.

}, issn = {1176-5283}, author = {Wilson PR and Grace ND} } @conference {41378, title = {Predicting copper status of cattle remains an engima}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {319-324}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {

Data are presented from several studies carried out by AgResearch and Massey University describing scenarios that affect the Cu status of grazing cattle. In all these studies, complex interactions between Cu, Fe, Mo and S make it difficult to predict Cu status. Increasing pasture Mo reduced percent absorption of dietary Cu in sheep by half (from 4.6\% down to 2.6\%). In contrast, the Cu kinetics in cattle could not be similarly simplified, so more sophisticated modelling calculations need to be applied. Even with moderate Mo intake (i.e. from pasture 0.8 mg Mo/kg DM), liver Cu content was quickly depleted in the cattle, reaching a low but stable level of 8 mg Cu/kg DM that appears to be a Mo-insensitive liver Cu store. In other trials, various Cu supplementation strategies have produced considerable but unexpected responses in liver Cu content. The risks and benefits of using liver Cu concentrations as an index of Cu status, and whether a multi-variable approach using tissue biomarkers, animal physiology, diet composition, and time of exposure is what is required to accurately predict the future Cu status for cattle are discussed.

}, issn = {1176-5283}, author = {Lee J and Knowles SO and West DM} } @conference {41308, title = {Predicting the onset of parturition during the late gestation in dairy cows using udder scoring and hormonal profiling}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {34-37}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Sixty-four cows were blood sampled and physical signs of impending parturition were scored daily from Day 272. Sampling and scoring ceased on Day 282 of gestation or when parturition occurred, whichever came about first. Mean udder development scores increased from 2.0 {\textpm} 0.76 ({\textpm} SD) on Day -10 (ten days prior to parturition) to 3.2 {\textpm} 0.72 ({\textpm} SD) on Day 0 (day of parturition) with 84\% of cows having an udder score of 3 or 4 on the day prior to parturition (Day -1). Teat distension, vulva swelling and oedema were not useful as indicators of imminent parturition. Udder score was the most useful predictor, but the low frequency of scores less than 2 and greater than 3 on any one day resulted in unstable models. Plasma samples were assayed for progesterone, PGF2a metabolites (PGFM), cortisol and oestradiol. Oestradiol concentration on Day 274 was a useful predictor of whether an individual cow would calve within eight days (P=0.02). Plasma oestradiol concentrations used to build models to predict whether a cow would calve within the next five days were accurate from Day 272 to 275 of gestation (P<0.05). Progesterone, PGFM and cortisol were unreliable indicators. }, issn = {1176-5283}, author = {Davis KL and Macmillan KL} } @conference {41299, title = {Presidential Address 2001 - What is wrong with the affluent, well-fed education society in which we live and work?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {1-2}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {The business of food production from animals, its attendant research and technology transfer industries, and science in general are all under attack from various factions within society. Generally, we see various causes come and - like fashions - go, but recently there has been an emergence of a number of attitudinal trends that seem to be {\textquoteleft}ganging up{\textquoteright} on the animal production sector. These appear to be increasing in number and intensity. It is as if the observation that {\textquotedblleft}Something is rotten in the state of Denmark.{\textquotedblright} {\textendash} so bluntly voiced by Marcellus in Shakespeare{\textquoteright}s Hamlet - could apply to some countries in the modern world, New Zealand included. As members of a society of animal production, we owe it to the livestock industry to counter these negative trends {\textellipsis} }, issn = {1176-5283}, author = {Barrell GK} } @conference {41325, title = {Producing a spreadable butter using modified milkfat}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {104-107}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {While traditional butter has been the spread of choice for many years because of the full flavour and excellent storage properties, since the advent of household refrigerators the lack of spreadability of butter when taken directly from the refrigerator has been seen as a negative characteristic. The approach taken in this study was to modify the composition of the milk from the cow through feeding trials carried out at Dexcel. However the final product must be able to be processed through a dairy plant and to have the performance that the customer requires. This means that it is not enough to know that the composition has changed but that the physical properties produced by these changes are advantageous. The goal therefore was to make the link between the properties required and to work to produce modifications that would produce those properties. This was achieved by defining the links between the product and the milkfat composition and making the physical properties such as solid fat content a target. The goal of producing a spreadable butter using modified milkfat was achieved however there is still a need to develop a profitable farm system. }, issn = {1176-5283}, author = {MacGibbon AKH and van der Does YE and Mabey BG and Deller GJ and Thomson NA} } @conference {41332, title = {Profitability of the use of new reproductive technologies in beef production systems}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {133-137}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Improvements in the productivity and profitability of beef breeding cows are highly desirable despite their valuable pasture management role. New reproductive technologies could help. The present work added a gross margin analysis to a previously reported biological model. Technologies, such as embryo transfer, sex ratio control, use of small cow- large calf breeds, were tested. At commodity beef prices, use of the new technologies in beef cows appeared to be mostly uneconomic, even if biological efficiency benefits could be captured, unless embryo prices were unrealistically low. The most profitable outcome was only 11\% more profitable than the status quo natural-mating system. However, profitability could be greatly enhanced if the returns on weaners born to the new technologies were greater than commodity returns. For example, at a mixed-sex embryo price {\textquoteleft}in the straw{\textquoteright} of $60 and assuming feed conversion and reproductive efficiency values similar to natural mating, use of embryo transfer broke even at $2.61/kg calf wean weight compared to a commodity return of $1.80. If {\textquoteleft}male only{\textquoteright} embryos were used, the breakeven return was $2.50. For $40 and $100 embryos, the respective breakeven premiums were 37 and 31\% and 62 and 54\%. The challenge, therefore, is to locate niche market returns not available to commodity production systems.}, issn = {1176-5283}, author = {Smeaton DC and Vivanco WH} } @conference {41345, title = {Ranking Romney sires on carcass value from a progeny test}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {183-187}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Interest in the meat-producing potential of rams of dual-purpose breeds such as the Romney has increased in recent years. To cater for this a group of Manawatu ram breeders have established a progeny test to determine sire differences in carcass value (CV) estimated as the sum of the value of individual carcass parts. In 2000-2001, detailed information was collected on 139 carcasses representing 12 sires. The average carcass weight and CV ({\textpm} sd) were 14.9 {\textpm} 1.9kg and $81.76 {\textpm} $10.76 respectively. A stepwise regression model with residual CV as the dependent variable was used to determine whether sire rankings on CV could be satisfactorily achieved by weighing only selected carcass parts. Weight of boneless leg (BL) explained the most variation with an r2 of 0.84. The addition of the weights of the frenched rack (FR) striploin (ST) each significantly (P<0.001) increased the amount of variation explained (r2 = 0.90), and increased the rank correlation between estimated and actual sire-group rankings from 0.71 to 0.95. A minimal model to rank the sires in this Romney progeny test is CV= -72.06+30.42*FR + 24.39*ST + 12.36*BL. Use of this model would avoid incurring the costs of weighing all carcass parts. }, issn = {1176-5283}, author = {PL Johnson and Purchas RW and Blair HT} } @conference {41375, title = {Recent developments in the detection and treatment of vitamin B12 deficiency in sheep and cattle at pasture}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {307-310}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {

Marginal Vitamin B12 deficiency is economically more important than a severe deficiency of the vitamin since the former can go unrecognised by the stockowner and hence uncorrected. This paper discusses recent work in this area by the authors, and reviews diagnostic procedures for the detection of Vitamin B12 deficiency in ruminants and developments in the treatment of this deficiency.

}, issn = {1176-5283}, author = {Judson GJ and Babidge PJ and Chen ZH and Sansom LN} } @conference {41348, title = {Reduction of tail length in New Zealand sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {195-198}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Literature evidence revealed several sources of genes that could be used to shorten the tails of sheep. Genes from the Northern short-tail group are preferable as there are no known detrimental effects on viability. Tail length from anus to tip, divided by the distance from anus to hock and calculated as a percentage was used to correct tail length for body size differences. Adjusted tail length of the progeny was best explained by additive effects for adjusted tail length of the sire (P<0.001) and dam breed (P<0.001). A small but significant interaction was also evident (P<0.01). Mean tail length was shortest for Finnish Landrace lambs (88mm) and longest for Wiltshire x Cheviot lambs (251mm). Cheviot lambs had long tails (226mm), while various crosses between Finnish Landrace and Cheviots suggest that mean tail length will be the average of the parents. The experiment suggests inheritance of a number of genes and that it will therefore be straightforward to produce genetically-docked tails using cross breeding followed by selection and interbreeding. }, issn = {1176-5283}, author = {Scobie DR and O{\textquoteright}Connell D} } @conference {41389, title = {Reproductive state differences in analgesic related systems and their influence on learning behaviours}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {368-371}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Kappa-opioids exert a more powerful analgesic effect in females than in male animals. In females, this is further enhanced close to and immediately post parturition. Learning behaviour is also altered in the female around this period. Recently it was demonstrated that changes in a brain receptor subunit (part of the glutamate NMDA receptor present in all mammalian brains), termed NR2B, accompanied these periods of apparent learning enhancement. In this paper, evidence is presented for a dependence of this increase in NR2B and learning ability on Kappa-opioid systems. Pharmacological antagonism of the Kappa-opioid system during the peri-parturient period prevents both an increase in NR2B and in learning behaviour. Application of Kappa-opioids at other periods increased NR2B numbers and learning behaviour in female animals and in male castrates co-treated with oestrogen. Intact males were unaffected. The data suggests a new concept linking pain perception and processing systems to reproductive state behaviours and learning abilities. }, issn = {1176-5283}, author = {Cook CJ} } @conference {41342, title = {Responses to poplar supplementation in ewes grazing drought pasture during mating}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {174-176}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Over the past 160 years, poplar and willow trees have been extensively planted on New Zealand pastoral land for shade and shelter, aesthetics and conservation purposes (Wilkinson, 1999). In North Island East Coast regions, some hill-country farmers are pruning the branches of poplar and willow trees to feed them to livestock during the late summer and autumn dry period, to supplement low-quality pastures. Drought poses a serious management issue for farmers in the East Coast regions of both the North and South Islands and predictions suggest droughts will become more frequent and severe in the future (Salinger, 2000). Supplementation with conserved forages, such as hay and silages, or grains such as barley, is a common management practice for farms suffering drought conditions (Leng, 1992). However, many East Coast hill-country farms have little or no flat land on which to produce hay or silage.}, issn = {1176-5283}, author = {McWilliam EL and Barry TN and Kemp PD and Lopez-Villalobos N and Cameron PN} } @conference {41376, title = {Role and importance of trace elements in New Zealand livestock. Fact and fiction}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {311-314}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {

In New Zealand as a result of extensive trace element supplementation animal response trials, an excellent database has been established on protocols to detect deficiencies, dietary trace element requirements, and the efficacy of many products to prevent deficiencies. However, situations still arise where the above information is not well evaluated or correctly implemented by some consultants and farmers.

}, issn = {1176-5283}, author = {Grace ND} } @conference {41351, title = {Ruminant methane emission measurements and estimates - from gut to globe}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {206-210}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {

Methane emissions from ruminants are New Zealand\’s largest source of greenhouse gas emissions. As a signatory to the United Nations Framework Convention on Climate Change and the Kyoto Protocol, New Zealand is committed to producing an accurate inventory of its methane emissions. Official estimates of methane emissions from ruminants have declined since 1990 but because of a failure to take account of changes in agricultural productivity these figures may be misleading. In comparison to Australia, the United Kingdom and the United States of America the methods used in New Zealand to calculate methane emissions comply less well with guidelines published by the Intergovernmental Panel on Climate Change although new methodologies are under development. Estimated errors in methane inventories are large (20-80\%) and although some of these errors can be reduced, large biological variation in the processes being quantified places a limit on this.

}, issn = {1176-5283}, author = {Clarke H} } @conference {41347, title = {Ryegrass staggers: genetics accounts for a six-fold difference in susceptibility between selection lines of lambs at Ruakura}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {191-194}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Ryegrass staggers (RGS) is a neuromuscular syndrome affecting susceptible ruminants when they graze perennial ryegrass (Lolium perenne L.) containing the mycotoxin-producing endophytic fungus Neotyphodium lolii. Genetic selection for divergence in RGS susceptibility began in 1993 at Ruakura in Romney-cross sheep, with single-trait RGS selection lines for resistance (R) and susceptibility (S) being established. Stock from both lines are repeatedly challenged when grazing together on high-toxin endophyte pastures, and scored for RGS. Lambs and {\textquoteleft}yearling{\textquoteleft} females (16 to 18 months of age) have been recorded each year, as well as breeding ewes and yearling rams in some years. Results up to the 2000 lamb crop are reported here, as well as preliminary records from the 2000 born yearling females. In the 2000 born lambs (n=61), 14\% and 88\% of the R and S lines showed clinical RGS, respectively (P<0.01). In the 1999 yearling ewes (n=48), corresponding percentages by line were 0 and 66\% respectively (P<0.01), whilst for the 2000 yearling ewes (n=18) percentages were 0 and 63\%, respectively (P<0.01). Line-crosses, born and reared together with the R- and S-line animals, had levels of clinical RGS between those of the corresponding R and S lines. From restricted-maximum-likelihood analyses, the single-record heritability for RGS in all stock classes was 0.17 {\textpm} 0.02, and the repeatability (between animals across years) was 0.28 {\textpm} 0.02. Breeding value estimates suggest that most of the divergence between lines has resulted from genetic change in the S line, but the genetic mechanism is not yet clear. Reasons for this asymmetry include: (1) greater genetic and phenotypic variation in the S line than in the R line, following a given challenge; (2) greater selection intensity applied in the S line; and (3) a major gene might be present, with an allele for resistance which is recessive or partially recessive. }, issn = {1176-5283}, author = {Aymes NC and Morris CA and Towers NR} } @conference {41358, title = {Salt supplementation of lactating cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {236-239}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {

Increased intensification of dairy production has contributed to a decrease in the sodium (Na) status of soils throughout New Zealand. This decline has the potential to detrimentally affect animal health and production. A trial was established to determine whether milk production responses would be obtained to sodium supplementation of cows receiving about 0.1\% (0.06-0.14\%) Na in pasture. The cows were in mid-lactation and were randomly allocated to either the control group or a group receiving 14 g Na/cow/day. Supplementation with 14 g Na did not increase milk yield or affect milk composition and there was no interaction with stocking rate. Serum Ca, Mg, Na, and Cl concentration were not affected by treatment, but serum K concentration decreased with Na supplementation. In summary: 0.1\% Na in the diet is sufficient for mid-lactation dairy cows producing 10-12 litres milk/cow/day (0.9 kg milksolids/cow/day) and a milk production benefit will not be achieved through Na supplementation.

}, issn = {1176-5283}, author = {MacDonald KA and Lile JA and Lancaster JAS and Coulter M and O{\textquoteright}Connor MB} } @conference {41333, title = {Seasonal variations in pasture quality on New Zealand sheep and beef farms}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {138-142}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Nineteen sheep and beef farmers in the Waikato, Tararua, Canterbury and Southland regions collected two pre-grazing pasture samples offered to either lambs or bulls once every month from autumn 2000 to autumn 2001. One sample of pasture on offer was collected to ground level and the other was hand plucked to represent pasture selected by animals. The samples were analysed by NIRS for chemical composition and dissected into morphological components. Energy concentration of herbage was lowest in autumn and highest in spring. Energy concentrations of offered pasture were 8.1, 9.2, 7.6 and 10.0 MJME/kg DM in autumn and 10.3, 11.6, 10.8 and 11.4 MJME/kg DM in spring in Waikato, Tararua, Canterbury and Southland, respectively. Crude-protein, fibre and soluble-carbohydrate concentrations reflected the changes in ME. Variations in dead material and reproductive stem were the main causes of changes in ME. Predicted liveweight gain of 350-kg bulls grazing pasture with a pre- and post-grazing herbage mass of 2500 and 1500 kgDM/ha respectively, were 0.4, 0.8, 0.0, and 1.1 kg/d in autumn, and 1.2, 1.5, 1.4 and 1.6 kg/d in spring, for Waikato, Tararua, Canterbury and Southland regions, respectively. It is concluded that high animal performance in summer and autumn may not be achieved in summer-warm regions without the addition of high-quality forages or supplements. }, issn = {1176-5283}, author = {Litherland AJ and Woodward SJR and Stevens DR and McDougal DB and Boom CJ and Knight TL and Lambert MG} } @conference {41380, title = {Sperm oviduct-epithelial-cell- binding assay: Development of an accurate sperm-counting method using flow cytometery and an evaluation of the sources of assay variance}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {330-333}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {

Survival of sperm within the cow reproductive tract is dependant on the binding of the sperm to the oviductal epithelial cells (OEC) and is a prime determinant of fertility. An assay of sperm survival was set up using the relative binding of sperm to cultured OEC on multi-well plates. A rapid accurate method of counting sperm in the presence of OEC was developed. A precise volume of cell suspension was mixed with a known number of fluorescent micro-beads and the mixture demembranated with detergent, stained with a DNA-binding fluorescence probe and analysed by flow cytometry. Correlations were obtained between flow cytometry and spectrophotometer measurements (R2 = 0.9815, P\<0.001) or manual haemocytometer counts (R2 = 0.9995, P\<0.001). Sperm was loaded into a cell culture well with confluent monolayers of OEC. After incubation sperm cells remaining in suspension in the well were removed. The difference in the number of sperm in the initial sample and that removed from the well indicated the number of sperm bound to OEC. While, there were large between-well variations for the same sperm sample, the assay was still able to distinguish differences between bulls in the binding ability of their sperm. Because a minimum of 10 wells per treatment are needed to statistically detect the difference, coupled with the high effort and time requirement in preparing the culture plates, the assay is impractical for large-scale experimental assays or for routine semen assessment.

}, issn = {1176-5283}, author = {Krzyzosiak J and McDonald RM and Vishwanath R and Smith JF} } @conference {41369, title = {Subclinical Johne{\textquoteright}s Disease in Sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {284-287}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {

This paper presents preliminary results from a 5-year study aimed at generating objective data on the effect of subclinical Johne{\textquoteleft}s disease on productivity in sheep. On two properties where Johne{\textquoteleft}s disease was considered to be a problem, replacement ewe lambs from a single generation were allocated to one of three groups. One group was vaccinated with the killed Mycobacterium avium subsp. paratuberculosis vaccine Neoparasec, another with the live vaccine Gudair, and the other group remained as unvaccinated controls. The vaccinated and control ewes were monitored over the ensuing four years for the following parameters: lesion size, live weight, fleece weight, scanning percentage, lamb production and weight of lambs weaned per ewe. Serology was also performed on a sample of animals from each group. On one property, the size vaccination-site lesions associated with Gudair declined at a more rapid rate than those associated with Neoparasec. However, results to date have failed to detect a significant difference in productivity between vaccinated and unvaccinated ewes in either flock, suggesting that subclinical Johne{\textquoteleft}s disease may not be an important cause of production loss in sheep. The trial is now in its final year.

}, issn = {1176-5283}, author = {Thompson KG and West DM and Anderson PVA and Burnham DL} } @conference {41361, title = {Total mixed rations versus pasture diets: Evidence for a genotype x diet on the concentration of amino acid-derived volatiles in milk}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {246-251}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {

The performance of overseas (OS) and New Zealand (NZ) Holstein Friesian (HF) dairy cows were compared on an all-pasture diet (Grass) or a total mixed ration (TMR). Dietary treatments had been imposed for two years prior to the 2000/2001 season for which these results are reported. The four treatments were NZ Grass (n=14); OS Grass (n=13); NZ TMR (n=14); and OS TMR (n=14). Genotype x diet interactions were observed for annual milk yield, milksolids yield, efficiency of milksolids production, liveweight gain during lactation, and the proportion of cows not in calf. Measurement of individual cow intake using alkane markers during early, mid, and late lactation identified when these genotype x diet interactions occurred. When fed TMR, OS HF performed better than NZ HF, but on grass NZ HF performed better than OS HF. This has implications for the selection of sires for the national herd, and for the use of different dairy cow genotypes in different dairying systems.

}, issn = {1176-5283}, author = {Kolver ES and Roche JR and de Veth MJ and Thorne PL and Napper AR} } @conference {41343, title = {Use of Lotus corniculatus to increase sheep production under commercial dryland farming conditions without the use of anthelmintics}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {177-178}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {Legumes are an important component of feeding systems in temperate zones to fix nitrogen and to produce high quality forage as a feed for livestock. However, marginal protein deficiency exists when ruminants are fed on fresh temperate forages due to high degradation rates of forage proteins in the rumen. Consequently, there is a large absorption of NH3 from the rumen, leaving absorption of essential amino acids (EAA) from the small intestine that is below animal requirements for these AA (Barry, 1982). Condensed tannins (CT) in Lotus corniculatus (Birdsfoot trefoil) reduce rumen protein degradability and increase EAA absorption from the small intestine (Waghorn et al., 1987). Separate feeding experiments with sheep have shown that CT in lotus increased wool production and milk secretion (Wang et al., 1996a\&b) and both ovulation rate during mating, and lambing percentage (Min et al., 1999: Min et al., 2001), all with no increase in voluntary feed intake (VFI). In addition, lambs fed lotus accumulated fewer dags than lambs grazed on perennial ryegrass (Lolium perenne)/white clover (Trifolium repens) pasture (Leathwick \& Atkinson, 1995). Each of these effects was measured in separate specific experiments. The objective of this study was to assess the effect of feeding Lotus corniculatus upon wool production and lamb weaning weight under commercial dryland farming conditions without anthelmintic drench input, using a systems approach, where effects upon animal productivity and parasites were measured in the same experiment. }, issn = {1176-5283}, author = {Ramirez-Restrepo CA and Barry TN and Lopez-Villalobos N and Kemp PD and Pomroy WB and McNabb WC and Harvey TG and Shadbolt NM} } @conference {41370, title = {Vaccination against Johne{\textquoteright}s Disease}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {288-289}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {

Vaccines are important tools to aid in the control of Johne{\textquoteleft}s disease. However, currently available live and killed whole organism vaccines have a number of drawbacks including hypersensitivity reactions at the injection site and sensitization to Mycobacterium bovis antigens. These problems lead to carcase downgrading and interference with TB control programmes. Alkaline phosphatase fusion methodology is being used to search for immunogenic cell surface associated and secreted proteins of a New Zealand field isolate of Mycobacterium avium subspecies paratuberculosis. The identification of immunogenic proteins of the bacterium will facilitate the development of a subunit vaccine. This type of vaccine contains only selected components of the organism and therefore it is likely to have fewer adverse side effects. In addition, it may be possible to design a vaccine that does not interfere with TB testing programmes.

}, issn = {1176-5283}, author = {Murray A and Dupont C} } @conference {41329, title = {A whole-farm model applied to a dairy system}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {120-123}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {The complex interactions between the biological, physical and management aspects of a farm can be represented mathematically using a computer model. A whole-farm model has been developed that links published sub-models for cow metabolism together with climate-driven pasture models, in a framework that allows for different management options. The model framework is written in VisualWorks Smalltalk, with submodels written in several programming languages linked to the framework using Microsoft COM protocol. Predictions of the whole-farm model have been compared with pasture and animal production data obtained from a dairy system trial at Dexcel in the Waikato. The system consisted of a herd of 19 cows, at a stocking rate of 3.2 cows/ha. The Whole Farm Model was used with Baldwin{\textquoteleft}s MOLLY cow model of metabolism, the McCall (1984) model of pasture growth, daily climate data and a management policy whereby daily activities on the farm were enacted by the framework. These activities included, for example, assignment of paddock for grazing, closure and cutting of paddocks for conservation, calving and drying off dates of each cow, and supplement feeding. At the end of each season the whole-farm model predicted 75\% of pasture growth compared with observed values assessed by visual assessment, 98\% of milk yield and 98\% of cow live weight. In addition to annual production by the whole farmlet, the whole-farm model can simulate individual animal and paddock production on a monthly and daily basis, so that patterns of change can be compared over the whole season. The whole-farm model is being used as a tool to design and analyse new dairy farm systems. }, issn = {1176-5283}, author = {Wastney ME and Palliser CC and Lile JA and MacDonald KA and Penno JW and Bright KP} } @conference {41311, title = {Winter dairy grazing systems: management practices and cow comfort}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {44-48}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {During winter, it is common practice to move dairy cows to a stand-off area. This project aimed to identify off-pasture management systems on farms and compare cow comfort on a variety of stand-off surfaces. A questionnaire was distributed in several dairying regions. The most common types of stand-off surfaces were concrete, or concrete in combination with another type of system. More farmers using woodchip surfaces reported that their cows laid down than those using concrete. The major health problem identified was lameness, and the majority of farmers believed that a woodchip pad worked best. Lying behaviours of 216 pregnant, non-lactating Friesian cows, on 18 farms in Waikato and Southland were recorded. Waikato cows were stood-off on woodchip pads, concrete and farm races. In Southland, covered and uncovered sawdust pads and crops were used. Cows spent longer (P<0.05) lying per day on woodchips (11.3 hrs) than on concrete (2.4 hrs) and races (4.1 hrs). Lying times for cows on covered sawdust pads (10.2 hrs) were not different from those on uncovered pads (11.5 hrs) or crops (11.2 hrs). A properly managed woodchip surface may cause less lameness and provide better opportunities for cows to rest than concrete surfaces or races. }, issn = {1176-5283}, author = {Stewart M and Fisher AD and Verkerk GA and Matthews LR} } @conference {41294, title = {Adapting the MOLLY cow model to fit production data from New Zealand animals}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {234-236}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {To assist in the planning of farm systems trials, Dexcel is developing a computer model of a pasture-based, rotationally grazed dairy system. The model includes published component models (or submodels) for cow metabolism and pasture growth, as well as climate and management information. It is currently being evaluated against production data obtained from the Whole Farm Efficiency Trial at Dexcel No 2 Dairy. The cow component being used is MOLLY, a dynamic model based on the underlying processes of ruminant digestion and metabolism. The parameters of MOLLY are based on animals that are efficient on high-energy diets. To make the computer model more accurate as a predictive tool for use in NZ, some of the parameters of the MOLLY submodel have been adjusted to fit the production data of NZ dairy cows on pasture, namely bodyweight changes and daily milk yields. MOLLY initially under-predicted by approximately 20\% the body weight of older cows (>4 years) for the pre-calving and early lactation periods. Resetting some parameters in MOLLY significantly improved the prediction of these bodyweight changes: to 2\% for the pre-calving period and 14\% for early lactation. Milk yield per cow was under-predicted in early lactation by MOLLY but the fit for each cow was improved by entering the observed peak daily milk value, although further fitting is required. We conclude that MOLLY is suitable for use as a research tool to gain insights into changes in metabolism of NZ cows grazed on pasture.}, issn = {1176-5283}, author = {Palliser CC and Bright KP and MacDonald KA and Penno JW and Wastney ME} } @conference {41262, title = {Age effects and interrelationships between wool characteristics of genotypes used to develop GrowBulk sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {100-103}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Groups of 10 ewes of four breeds (Romney, Dorset cross Romney, Texel cross Romney, (Dorset x Romney) cross (Texel x Romney) born in two years (1994, 1995) were used to investigate the changes of wool characteristics with increasing age. Each ewe was wool sampled at hogget shearing in October and at each subsequent annual shearing in July until 1999. Romney fleeces had higher clean fleece weight, lower core bulk, longer staple length, less fibre curvature and lower crimp frequency. All genotypes exhibited similar ageing patterns for each measured wool characteristic except fibre diameter variability. Days to form a crimp increased, staple length and core bulk did not change and fibre curvature and crimp frequency decreased with increasing age. Clean fleece weight and fibre diameter increased to a plateau between 2 and 4 years of age before declining. The repeatability of all individual characteristics decreased with increasing age. There were no consistent differences in the relationship between core bulk and a combination of fibre curvature and fibre diameter across genotypes within age groups. Crossing Dorset and Texel rams over Romney ewes to generate a specialty high wool bulk composite genotype did not influence the age trends and interrelationships between individual wool characteristics inherent in the base Romney flock. }, issn = {1176-5283}, author = {Sumner RMW and Upsdell MP} } @conference {41237, title = {Animal production research for the shellfish aquaculture industry}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {28-30}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Aquaculture is a globally significant food production industry. Aquaculture in New Zealand has grown rapidly over the past decade, and it is widely considered as an area of significant growth potential within the country{\textquoteright}s economy. The mussel industry is the biggest sector, followed by salmon, oyster and paua. The Mussel Industry Council has a Sextant database that allows continuous interactive planning among all stakeholders and demonstrates the crucial role of R\&D in the realisation of strategic goals. The industry is expected to grow at 7\% pa within the next decade. This growth will require new animal production activities such as hatchery spat production, selective breeding and husbandry for animal health and condition. These activities will be based on R\&D outputs such as the ability to condition broodstock, cost- effective methods for early spat rearing, and methods for the cryopreservation of gametes and embryos. To achieve these outputs, the industry supports research on the biology, ecology and genetics of the mussel, hatchery and nursery technology, shellfish selective breeding and cryopreservation, stress and disease physiology. New areas of research on shellfish production provide opportunities for the application of generic animal production expertise.}, issn = {1176-5283}, author = {Kaspar HF} } @conference {41258, title = {Biotechnology, farmers and the media}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {87-89}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {This study compared information farmers and the public are given about biotechnology, using stories from The Dominion and The New Zealand Farmer. 64\% of stories were in favour of biotechnology. Biotechnology benefits made up 38\% of the arguments in stories, followed by threats of not going ahead with biotechnology. Farmers were not well represented as sources. Two focus groups, one of rural producers, the other urban consumers, were asked to share their views about biotechnology. Urban consumers were more concerned about biotechnology than rural producers. Urban consumers wanted to know about dangers and safety while rural producers wanted to know about benefits. The study concluded wider debate is needed; farmers need to be actively involved; reporting needs to be more conscious; biotechnology proponents have to stop threatening people; rural producers have to understand their consumers better; and we should all ask more questions. }, issn = {1176-5283}, author = {Taylor MJ} } @conference {41250, title = {Black-backed gulls (Larus dominicanus) and their role in the spread of Salmonella Brandenburg}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {71-73}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {During the time sheep are aborting from Salmonella Brandenburg infection, black-backed gulls have the ability to contaminate stock water and pasture with S. Brandenburg. This enables these birds to play a significant role in the local spread of diseases caused by this organism. They also have the ability to spread other diseases, such as sheep abortions due to Campylobacter. }, issn = {1176-5283}, author = {Clark RG} } @conference {41230, title = {Can a mathematical model accurately predict intake of grazing animals? Testing the Q-Graze model}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {4-7}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {A decision support model, Q-Graze, was developed to assist farmers with grazing management decisions based on visual assessments of pasture quality. To evaluate the model{\textquoteright}s ability to predict dry matter intake and diet composition, it was tested against pre- and post-grazing herbage mass and composition data from a trial conducted at the Whatawhata Research Centre involving bulls and steers grazing mixed-species hill pasture. Q-Graze was able to predict apparent intakes of grass leaf, grass stem, legume, weed, dead material and total dry matter with means and residual standard deviations 6.4 {\textpm} 1.5, 0.6 {\textpm} 1.3, 1.3 {\textpm} 0.7, 1.2 {\textpm} 0.8, 1.5 {\textpm} 1.4 and 10.6 {\textpm} 2.3 kg DM per animal per day, respectively. These predictions accounted for R2 = 83\%, 15\%, 76\%, 73\%, 54\% and 55\%, respectively of the variation in the apparent intakes calculated from the data. This indicates that Q-Graze is able to predict herbage intake and diet selection of cattle grazing mixed hill-country pastures to a high degree of correlation. The limiting factor was the measurement error of pre- and post-grazing herbage mass, rather than the model design. Model testing for additional animal and pasture types is currently being undertaken. }, issn = {1176-5283}, author = {Woodward SJR and Lambert MG and Litherland AJ and Boom CJ} } @conference {41273, title = {Changes in plasma, milk and urinary magnesium concentrations in pasture-fed dairy cows in early lactation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {152-155}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Estimates of magnesium (Mg) balances and plasma Mg concentrations of 51 dairy cows were obtained at 2-weekly intervals from calving during the first 3 months of lactation (late August to early December). During that period estimated 24h Mg excretion increased from 1.1 to 3.2g Mg/d (P<0.001) and varied with age. Plasma magnesium concentrations in 10\% of samples were below the threshold (0.6 mM) at which productivity is considered to be impaired. Within cow repeatability for plasma Mg was 0.70 {\textpm} 0.048. Individual cows showed unique patterns in the relationship between plasma Mg and estimated urinary Mg output. Mean milk Mg concentration was 104 {\textpm} 0.54 mg/l, almost 20\% lower than published values used in estimates of net requirements for Mg. Individual cow repeatability for milk Mg concentration was 0.67 {\textpm} 0.082 which, together with the plasma data, suggest an important genetic component in Mg homeostasis. This will need to be accounted for in models of Mg metabolism. }, issn = {1176-5283}, author = {Thielen M and Sedcole JR and Sykes AR} } @conference {41286, title = {A comparison of dairy farming between New Zealand and Japan}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {203-206}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {The productivity and financial performance of dairy farms in New Zealand and Japan (Hokkaido) were analysed. Relative to Hokkaido, New Zealand has lower yield of milk solids per cow, but higher production per hectare because of their pasture grazing systems. The value of milk solid is much higher in Hokkaido than New Zealand (NZ$14.7 vs. NZ$3.5/KgMS), and the total expenses of producing milk solids are much higher in Hokkaido than in New Zealand (NZ$11.5 vs. NZ$3.0/KgMS). New Zealand has a lower variable cost, but higher fixed expenses and higher cash surplus ratio per farm compared with Hokkaido. There is also remarkably high interest expenditure in New Zealand caused by non-subsidised loan procurement from finance organisations. Total farm expenses per cow in New Zealand is only at about 1/10 of Hokkaido expenses. There is a marked difference in financial structures between the two countries, especially in turnover ratios of gross assets. The results suggest that it is important for dairy farmers in Hokkaido to consider not only cost savings achieved through grazing systems, but also to consider that grazing systems make only poor utilisation of capital. }, issn = {1176-5283}, author = {Ozawa T and Lopez-Villalobos N and Blair HT} } @conference {41281, title = {Controlled Calving with induction of parturition on Day 274 of gestation in dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {184-187}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {The response and effects of inducing parturition on Day 274 of gestation in dairy cows with synchronised conception dates was investigated in selected herds around Victoria. Cows (n=227) were injected with dexamethasone trimethylacetate (30 mg, i.m.) with 444 herdmates as controls. Randomisation was based on scored udder development. Blood samples taken on Days 272 and 274 had average plasma progesterone concentrations of 4.50 and 4.49 ng/ml respectively (P>0.05). Treated (T) cows calved an average of 2.61 {\textpm} 0.21 days before their due date, compared to 0.17 {\textpm} 0.20 days for control (C) cows (P<0.001). There were no differences in the proportion of cows displaying symptoms of milk fever, mastitis, paralysis or acute metritis. The incidence of retained foetal membranes at 12h postpartum differed between the two groups (3\% vs. 16\%; C vs. T; P<0.005). Control cows received more assistance at parturition (15\% vs. 10\%, P<0.05). There were no differences between groups for cow or calf mortality, or for any parameter of milk yield. The effect of treatment on subsequent fertility was minimal. }, issn = {1176-5283}, author = {Davis KL and Macmillan KL} } @conference {41261, title = {Correlations among beef carcass composition and meat quality traits from a genetic marker trial}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {96-99}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {A collaborative beef cattle project between AgResearch and Adelaide University is described, which had the aim of identifying genetic markers (DNA markers) for carcass composition and meat quality traits. Two extreme breeds were used, the Jersey and Limousin, and first-cross Jersey x Limousin bulls were mated to cows of both breeds to produce experimental animals in two herds, in New Zealand and Australia. The present paper provides information on relationships among some traits recorded in the New Zealand herd, with a total of 416 back-cross cattle of both sexes slaughtered as 2-year-olds at Ruakura in the springs of 1998 and 1999. The recorded data included hot carcass weight and the butcher-dissected weights of meat, fat and bone in the right side, expressed as percentages of side weight (MP, FP and BP respectively). The pH decline in the right striploin, removed from the carcass after dressing and maintained at a constant 15{\textdegree}C, was monitored to derive the initial (pH1), ultimate (pHu), and the rate of fall of pH. Average shear force (SAVG) and the half-life of the ageing rate (SHLF) were measured in striploin steaks cooked immediately after rigor and then at intervals until ultimate tenderness. Percentage weight loss (PWL) during cooking was recorded. Also measured in the striploin were the concentrations of three metabolic enzymes, lactate dehydrogenase (LDH), isocitrate dehydrogenase (ICDH) and 3-hydroxyacyl-Coenzyme A dehydrogenase (HAD), and the proteolytic enzymes m- and milli-calpain, and their inhibitor calpastatin (CAST). Glycogen concentration in the muscle at slaughter, expressed as the glycolytic potential (GLYP), was estimated from the sum of the concentrations at rigor of glucose, glucose-6-phosphate, lactate and residual glycogen. The range of pHu values was small, probably because all animals were regularly handled. Correlations, after adjustment for breed group, sire and slaughter group, included: MP with FP, -0.82; PWL with MP, 0.20; PWL with FP, -0.29; MP with enzymes LDH, ICDH and HAD, 0.22, -0.21, -0.03; FP with ICDH, 0.16; SAVG with SHLF, 0.48; SHLF with CAST, m-and milli-calpain, 0.28, -0.14, 0.03; CAST with m- and milli-calpain, 0.26, 0.38; GLYP with pH1 and pHu -0.01 and -0.17. Overall, HCW, MW and composition traits were not correlated with pH traits or SAVG, or m- or milli-calpain concentrations; HCW and MW were positively correlated with LDH and GLYP. }, issn = {1176-5283}, author = {Morris CA and Daly CC and Cullen NG and Hickey SM} } @conference {41278, title = {CowTrakker technology for improved heat detection}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {172-175}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Devices designed to detect motion (CowTrakker{\texttrademark}, Bou-Matic, USA) were attached to Holstein-Friesian cows of either NZ or overseas origin. Animals of each strain either grazed pasture or were fed a total mixed ration. Milk samples were collected twice weekly and progesterone content analysed to identify ovulation events. Cows had tail paint applied from 2 weeks after calving, and were observed twice daily at milking for oestrous activity. Recording continued until 6 weeks after the planned start of mating (PSM). Cows were artificially inseminated following a progesterone-based synchrony programme at PSM. CowTrakker{\texttrademark} data were analysed using four algorithms (T3/1, T3/3, T10/1 and T10/3), which varied according to the period of the rolling average used (3 or 10 days) and the standard deviations from that average (1 or 3). These measurements were related to behavioural observations and the occurrence of ovulation. There was a significant number of false positive events detected by the CowTrakker with all algorithms (sensitivity: 12.3, 46.9, 62.3 and 81.5\%; specificity: 67.1, 88.4, 95.4 and 99.0\%, for T3/1, T3/3, T10/1 and T10/3, respectively) as compared to behavioural observations alone (sensitivity: 71.6\%; specificity: 99.6\%). The CowTrakker{\texttrademark} was a useful heat detection aid, but must be used in conjunction with careful behavioural observations in order to interpret the high proportion of false positive events that are recorded.}, issn = {1176-5283}, author = {Verkerk GA and Claycomb RW and Taufa VK and Copeman P and Napper A and Kolver E} } @conference {41234, title = {Creep grazing, a method for investigating pre-weaned lamb diets?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {20-22}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Creep grazing as an experimental method offers potential as a research tool for investigating the diet of the pre-weaned lamb, without the confounding associated with both the ewe and lamb sharing the same pasture during lactation. Eighty- four Romney x Poll Dorset ewes with single or twin lambs were set stocked in a randomised block design (wooden gates used to create creep areas) at 15.2 ewes/ha, 4 weeks after lambing. Subterranean clover was established in four creep, and 2 shared areas in autumn. Herbage mass and composition were measured weekly in the creep and shared pasture areas. }, issn = {1176-5283}, author = {Hyslop MG and Moffat CAM} } @conference {41238, title = {Cryopreservation of shellfish sperm, eggs and embryos}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {31-34}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Cryopreservation of gametes and embryos plays a key role in the advanced areas of animal production. It will also play a central role in future aquaculture. The techniques to cryopreserve gametes are well understood in domestic animals such as sheep and cattle. In contrast, research on shellfish cryopreservation is scarce. A major limitation of previous shellfish work is that fertilisation or short-term survival has been taken as the measure of success, which has not been validated in terms of successful development and growth of larvae. This manuscript briefly describes the approach to the problem by this research team and highlights some of the similarities and differences between the procedures used with shellfish and domestic animal gametes.}, issn = {1176-5283}, author = {Smith JF and Pugh PA and Tervit HR and Roberts RD and Janke AR and Kaspar HF and Adams SL} } @conference {41248, title = {Deer and pigs as hosts of bovine tuberculosis, and their potential use as sentinels of disease presence}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {64-67}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Feral pigs and wild deer often have the highest local prevalences of bovine tuberculosis (Tb) of any of the wild animal species present in infected areas. Despite this, pigs have long been regarded as {\textquoteleft}spillover{\textquoteright} hosts that become infected mainly by scavenging infected carrion, rather than by transmission from other pigs. Deer, in contrast, appear capable of independently sustaining the disease when their densities are high, but not when they are low. Most infection in wild deer in New Zealand also appears to be spillover infection. As spillover hosts, both pigs and deer have the potential to be used as sentinels for identifying when and where Tb occurs in local possum populations. Within the constraints of local availability, pigs appear to be potentially more valuable as sentinels than deer. }, issn = {1176-5283}, author = {Nugent G} } @conference {41277, title = {Diet and genotype affect plasma calcium, magnesium and phosphorus concentrations in the periparturient cow}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {168-171}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {The literature is inconsistent with regard to the effect of diet in the periparturient period on the health and production of dairy cows, and there is little or no data on the effect of genotype. Fifty-six dairy cows of two different genotypes (Overseas Holstein-Friesian (OSHF) and New Zealand Holstein-Friesian (NZHF)) were randomly allocated to two dietary regimens. Half of each genotype group received a pasture/pasture silage diet pre-calving and a pasture diet post-calving, while the other half received a total mixed ration pre- and post-calving. Cows receiving the total mixed ration pre-calving had a lower (P<0.05) plasma calcium concentration on the day of calving and the day following calving. Conversely, cows of both genotypes offered pasture had lower (P<0.01) plasma magnesium and phosphorus concentrations pre- and post-calving compared with cows fed a total mixed ration. OSHF cows had lower plasma calcium (P<0.05) and magnesium (P<0.001) concentrations post-calving. Plasma phosphorus concentrations were unaffected by genotype. Herds with a high proportion of OSHF genetics are at an increased risk of parturient hypocalcaemia and hypomagnesaemia. Recommended daily allowances for these minerals may need to be increased to allow for this predisposition.}, issn = {1176-5283}, author = {Roche JR and Kolver ES and de Veth MJ and Napper A} } @conference {41231, title = {Digestion kinetics of mature grasses}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {8-12}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Digestion kinetics were measured for mature (green and non-senescent) components of five grass species using in sacco and in vitro incubations to define rates of degradation and nutrient release. The data will be incorporated into a dairy nutrition simulation model to identify limitations in nutrient supply to cows grazing mature pasture in late spring. Perennial ryegrass, tall fescue, Yorkshire fog, phalaris and paspalum were hand separated into leaf, stem and inflorescence for incubations. Percentages of fibre (NDF) in DM fractions ranged from 50-69\% (leaf), 63-75\% (stem) and 50-68\% (inflorescence). Crude protein concentrations in the DM of the respective fractions were 7.5-23.7\%, 3.8-8.3\% and 7.9-12.3\%. Soluble DM (\% of the total) determined after mincing accounted for 31-53\% of leaf, 26-55\% of stem and 20-48\% of inflorescence, and fractional (h-1) degradation of the insoluble DM was very slow, ranging from 0.034-0.113 (leaf), 0.025-0.036 (stem) and 0.033-0.072 (inflorescence). After 24 hours of in vitro incubation plant nitrogen content become limiting for fermentation in most instances. }, issn = {1176-5283}, author = {Chaves AV and Waghorn GC and Brookes IM and Burke JL} } @conference {41235, title = {Early indications that feeding Lotus will reduce methane emissions from ruminants}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {23-26}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Ruminant livestock produce at least 75\% of New Zealand{\textquoteright}s total methane emissions and are a major contributor of greenhouse gas emissions. Most ruminant methane arises from microbial activity in the rumen (methanogenesis) and is released through the mouth and nose. Methane production per unit feed intake or per unit production can be reduced by improving diet quality, for example, including legumes in a pasture diet. A preliminary investigation with wether sheep showed lower daily methane outputs per unit dry matter intake (DMI) when fed Lotus pedunculatus (a condensed tannin-containing legume) than ryegrass-based pasture or lucerne (14.5 vs. 20.4 vs. 19.0 gCH4/kg DMI). Friesian dairy cows fed either Lotus corniculatus silage or perennial ryegrass silage had similar total methane outputs (376.7 vs. 344.4 g CH4/cow/day; ns). However, methane emissions were lower from cows fed Lotus silage when expressed per unit DMI (26.90 vs. 35.13 g CH4/kg DMI; P<0.001) and per unit production (378 vs. 434 g CH4/kg milksolids; P<0.05) as a result of the higher intake and milksolids yield. The mitigation of methane emissions from animals fed Lotus species was due in part to a higher nutritive value relative to pasture but effects of condensed tannins on methanogenesis warrants further investigation. }, issn = {1176-5283}, author = {Woodward SL and Waghorn GC and Ulyatt MJ and Lassey KR} } @conference {41266, title = {The effect of condensed tannins in sainfoin (Onobrychis viciifolia) and sulla (Hedysarum coronarium) on the digestion of amino}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {116-119}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Two experiments were conducted in order to compare the effect of condensed tannins (CT) in sainfoin (Onobrychis viciifolia) and sulla (Hedysarum coronarium) on the flux of amino acids (AA) through the gastrointestinal tract of sheep. In each experiment, one group of sheep (PEG group; CT inactive) received an intraruminal infusion of polyethylene glycol (PEG) to inactivate the CT present in the forages, while the other group received an intraruminal infusion of water (Tannin group; CT active). The CT in sainfoin (38.1 g/kg DM) had no significant effect on apparent AA absorption from the small intestine. However, in the sulla-fed sheep, AA absorption in the small intestine was significantly increased by CT (P<0.05; CT = 64.4 g/kg DM). In both forages a shift in AA digestion from the rumen to the small intestine was seen with increased abomasal fluxes of AA in the Tannin group of sainfoin- (92 versus 101 g/day in the PEG and Tannin group, respectively; P<0.05) and sulla-fed (65 versus 83 g/day; P<0.001) sheep. Differences in the digestion and absorption of AA in the two forages may be associated with differences in chemical structure of the CT. }, issn = {1176-5283}, author = {Bermingham EN and Hutchinson KJ and Revell DK and Brookes IM and McNabb WC} } @conference {41292, title = {Effect of grain or buffer supplementation on milk solids yield and rumen fermentation patterns of cows grazing highly digestible herbage in spring}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {224-228}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Sixteen rumen-fistulated Holstein Friesian cows in early lactation were offered 40 kg herbage dry matter (DM)/cow/day (to ground level). The objective of the experiment was to investigate the economics of feeding cereal grain supplements to cows grazing highly digestible ryegrass herbage in spring and determine the impact of grain feeding on rumen conditions and milk composition. Six kilograms DM of cereal grain were offered to eight cows, while the other 8 cows did not receive grain. Superimposed on these grain supplementation rates were 0 or 300 g sodium bicarbonate in a 2x2 factorial design. The inclusion of grain in the diet reduced herbage intake (from 16.7 - 12.7 kg DM/day, P<0.01) and the neutral detergent fibre concentration of the total diet (from 410 g/kg - 325 g/kg DM). Grain feeding reduced milk fat concentration (from 41.7 - 34.3 g/kg, P<0.05) and increased milk protein concentration (from 32.8 - 34.6 g/kg, P<0.05). Grain feeding depressed the rumen fluid concentration of acetic acid and increased that of propionic acid, resulting in a lipogenic:glucogenic ratio (acetic + butyric:propionic acid ratio) below 3:1 for both grain treatments. The milk responses from cows consuming concentrates with highly digestible herbage in spring were low (-0.4 - 0 kg 4\% fat corrected milk/kg DM grain consumed) and did not improve the returns to farmers during the period of feeding. The most profitable use of concentrates is likely to come after spring calving cows have reached their peak and herbage quality begins to decline. }, issn = {1176-5283}, author = {Dalley DE and Roche JR and Grainger C} } @conference {41264, title = {Effect of incorporating East Friesian genes on wool characteristics}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {109-111}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {A study carried out on eight farms examined the effect of crossing the present flock (Corriedale or Romney) with East Friesians. Crossing East Friesian over Corriedales increased fibre diameter from 28.5{\textpm}0.1 {\textmu}m to 31.7{\textpm}0.2 {\textmu}m compared with straightbred Corriedales. Inclusion of up to {\textthreequarters} East Friesian breeding over Romneys reduced the fibre diameter from 36.3{\textpm}0.4 {\textmu}m to 31.4{\textpm}1.3 {\textmu}m compared with straightbred Romneys. The effect on bulk of crossing East Friesians over Corriedale was variable. Based on an average wool price of 500c/kg clean for 28 {\textmu}m Corriedale hogget fleece wool between 94/95 and 98/99, a change of 3.0 {\textmu}m is likely to reduce the expected wool price by approximately 7\%. Based on an average wool price of 400 c/kg clean for 36 {\textmu}m Romney hogget fleece wool, a change of 4.0 {\textmu}m is likely to increase the expected wool price by approximately 13\%.}, issn = {1176-5283}, author = {Reid TC and Booker J} } @conference {41276, title = {Effect of premating iodine supplementation of ewes fed pasture or a brassica crop prelambing}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {164-167}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {On two sheep farms with different winter feeding systems, namely pasture only (farm A) or pasture then swedes or swedes/turnips/kale for 6 to 8 weeks prelambing (farm B), 700 ewes/farm were randomly assigned to 2 groups of 350 animals to assess animal performance. About 5 weeks premating, one group was injected with 390 mg iodine (as Flexidine iodised oil) intramuscularly. Iodine supplementation increased and maintained serum and milk I concentrations for at least 210 days ({\textmu}g/L; farm A, serum 43 v 65; milk 72 v 197. Farm B, serum 29 v 45; milk 26 v 132), but did not affect potential lambing percentage at scanning, perinatal mortality, or lambing percent (farm A, 140 v 150\%; farm B, 138 v 130\%). On farm A no goitre was observed among the 77 lambs postmortemed, regardless of I treatment of the ewes. On farm B goitre was observed in 85\% of the 34 lambs postmortemed from untreated ewes, but not among the 36 lambs from treated ewes. In the following year, the trial was repeated with 50 ewes/group to monitor changes in I status, and the treatment significantly increased serum I over time but had no consistent effect on serum T4 and T3 concentrations. Supplementing ewes premating with long-acting injectable I prevented goitre in newborn lambs from ewes fed swedes or swedes/turnips/kale as a winter supplement. }, issn = {1176-5283}, author = {Grace ND and Knowles SO and Sinclair GR} } @conference {41289, title = {Effect of stage of lactation on the efficiency of Jersey and Friesian cows at converting pasture to milk production or liveweight gain}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {213-216}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {A study comparing Jersey (J) and Friesian (F) cows in early (EL), mid (ML) and late (LL) lactation and offered either ad libitumpasture (P) or restricted pasture allowance + a concentrate (PC) was conducted. Breeds were grazed at a similar live weight (LWT)/ha (1340 and 1850 kg LWT/ha for P and PC respectively). F cows produced 10\% more MS/cow/day than J cows. DM intake (DMI) on P was 13.6 kg DM/cow/day for F and 11.3 kg DM/cow/day for J cows but if expressed at constant LWT, J consumed more than F cows (30.3 versus 28.0 + 0.8 g DMI/kg LWT). During EL, J cows gained less live weight than F cows but in LL the reverse occurred. An interaction between breed and stage of lactation also occurred for the conversion efficiency of pasture DM to milkfat, protein, casein and MS. For the yield of milkfat, protein and casein J cows in EL were more efficient than F cows but in LL no breed effect on the conversion efficiency of pasture to these components occurred. The difference between breeds in partitioning feed to milk solids and liveweight gain at different stages of lactation suggests different management opportunities for each breed to more efficiently convert pasture to MS.}, issn = {1176-5283}, author = {Thomson NA and Kay JK and Bryant MO} } @conference {41271, title = {Effects of insulin on amino acid uptake by the mammary gland of the pasture-fed lactating ruminant}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {144-147}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Twelve lactating ewes housed indoors were allocated to one of two treatment groups (hyperinsulinaemic euglycaemic clamp (HEC) or control) in a randomised block design experiment. Mammary amino acid uptake from plasma and utilisation for milk protein synthesis was measured during the fourth day of the HEC using the arterio-venous concentration difference (A-V) technique. There was no change in milk protein output during the HEC (P>0.05). The HEC induced a significant decrease in arterial concentrations of all essential amino acids (EAA) except for histidine and an increase in the extraction efficiency of isoleucine (HEC, 61 {\textpm} 3\% vs. control, 52 {\textpm} 3\%, P<0.05) and leucine (HEC, 64 {\textpm} 3\% vs. control, 53 {\textpm} 3\%, P<0.05). There was no significant change in extraction efficiency of other EAA or mammary blood flow. The ratio of amino acid uptake from plasma to output in milk protein suggested deficits in uptake for some EAA in both treatments, especially histidine. These results indicate that the mammary gland can adapt to a changing arterial supply of amino acids to maintain milk protein output by increasing extraction efficiency and/or a greater reliance on amino acids supplied by erythrocytes and/or plasma peptides. }, issn = {1176-5283}, author = {Back PJ and Davis SR and MacKenzie DDS and Harris PM and Roy NC and Lee J} } @conference {41242, title = {Evaluation of an oestrone sulphate dipstick immunoassay for pregnancy testing mares}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {45-47}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Serum samples from 213 mares were received for routine pregnancy testing and analysed by a conventional oestrone sulphate (OS) enzymeimmunoassay (EIA) and a new OS dipstick immunoassay. OS concentrations, measured by EIA, in 122 of the samples were <10 ng/ml, indicating the mares were not pregnant. The same 122 samples also returned a {\textquoteleft}not pregnant{\textquoteleft} diagnosis when analysed by the dipstick immunoassay. The remaining 91 samples returned diagnoses of {\textquoteleft}pregnant{\textquoteleft} by the OS EIA, i.e., OS concentrations were >20 ng/ml. Of these, 89 also returned a {\textquoteleft}pregnant{\textquoteleft} diagnosis by the dipstick assay, but 2 returned a {\textquoteleft}not pregnant{\textquoteleft} diagnosis. Both these mares were found to be pregnant on follow up, indicating that the dipstick test had returned a false negative diagnosis in each instance. These results show that there is 100\% agreement between the conventional OS EIA and the new dipstick assay in diagnosing {\textquoteleft}non pregnancy{\textquoteleft}. However, the dipstick assay may return a small proportion (2.2\%) of false negative diagnoses relative to the EIA. Overall, the new dipstick immunoassay offers a practical alternative to the OS EIA for diagnosing pregnancy status in mares. }, issn = {1176-5283}, author = {Stewart J and Henderson K} } @conference {41251, title = {Experimental infection of pregnant sheep with attenuated Salmonella typhimurium}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {74-77}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Salmonellosis occurs in many animal species including sheep, and may cause pathology of the gut and possible abortion. If attenuated strains were to be used for future control, their establishment in the host and shedding pattern needs to be determined. Fifty-one pregnant ewes were obtained from the Lincoln University Research Farm and assigned randomly to five treatment groups. At approximately 1 month before lambing, the groups were given attenuated S. typhimurium (cya-, crp-) by different routes and doses as follows: 1010 colony-forming units (cfu) intranasally (i.n.), 109 cfu i.n., 1010 cfu subcutaneously (s.c.), 109 cfu s.c., and control (saline i.n. and s.c.). Selected animals were slaughtered at days 4 and 14 post infection for bacteriological culture from the mesenteric and retropharyngeal lymph nodes, intestinal contents and lamb stomach contents. The experimental organisms were isolated using selective cultures and identified by latex agglutination test and fermentation reactions. Following infection there were no changes in rectal temperature or significant clinical signs except two cases of abortion in the 1010 cfu s.c. group. The number of animals shedding organisms in their faeces decreased with time from 12 ewes at day 1 to one ewe at day 4 and day 7. Most of them were from the 1010 i.n. group. Subcutaneous injection of 1010 cfu induced abortion in two of 11 ewes, as organisms were detected in their faeces and the aborted lambs. However, no organisms were detected in faeces, intestinal contents or the lamb stomach contents of the ewes that were killed at days 4 or 14. In the two ewes that had received 1010 cfu i.n. and were killed at day 4, organisms were detected in the mesenteric and retropharyngeal lymph nodes. In summary, the administration of the attenuated S. typhimurium (cya-, crp-) at 1010 cfu caused asymptomatic short-term faecal shedding and abortion when given i.n. and s.c., respectively. }, issn = {1176-5283}, author = {Khalil AM and McFarlane RG and Shand NA and Leslie SE and Christensen NH} } @conference {41280, title = {Factors associated with the incidence of {\textquoteright}Phantom cows{\textquoteright} in Australian dairy herds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {180-183}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {A major cause of delayed pregnancy and reproductive wastage in Australian dairy cattle is the failure of cows to be re-inseminated within 24 days of an unsuccessful insemination. Four commercial herds were observed to determine the incidence of this syndrome. Those cows inseminated in the first three weeks of the mating season (n=721 cows) were observed for a subsequent return to service, and non-return cows were diagnosed for pregnancy. Overall, 45\% of cows were confirmed pregnant to first service, 37\% returned to service within 24 days, and 19\% were diagnosed as non-return, non-pregnant cows (Phantom cows). The majority of cases of Phantom cows (89\%) were explained as having: a) a CL but not returning for service; b) having an abnormally long return to service (25 to 39 days); or, c) reverting to an anoestrous state. Other cases (<5\% incidence) included ovarian cysts, pyometra and uterine adhesions. Repeated diagnoses of pregnancy identified few cases in which a pregnancy appeared to have failed (3.3\%). The incidence of Phantom cows was higher for CIDR-treated anoestrous cows than cows synchronised with prostaglandin, and lowest for those cows not treated. These observations form the basis for further study of this syndrome in Australian herds. }, issn = {1176-5283}, author = {Nation DP and Morton J and Cavalieri J and Macmillan KL} } @conference {41240, title = {The farming of game species .... horses for courses}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {38-41}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Pastoral-based animal industries utilise only a handful of domesticated species. The relatively recent development of farming "game" species (i.e., species traditionally harvested by hunting) has been largely prompted by changing first-world consumer demographics. Pastoral farming of red deer in NZ is often seen as a glowing example of diversification away from traditional livestock. In tropical regions, specific species adapted to local climate, vegetation and diseases include axis deer, sambar deer and rusa deer. In the arctic regions, reindeer are the species of choice due to their cold tolerance and food selection habits. Various species (e.g., antelope, buffalo, elephants, zebra, etc) form the basis of a growing game ranching industry in the dry savannah regions of Africa, structured around sustainable, low-density, multi-species grazing of rangelands that are generally unsuited to domestic livestock due to aridity or parasites/diseases (e.g., tsetse fly). Thus, there are many examples of successfully picking "horses for courses" ... game species suited to particular environments. Conversely, there is a danger that in the enthusiasm to promulgate particular systems around the world, there are occasions when "horses are on the wrong courses". Classic examples for this include attempts to farm (1) tropical species in temperate environments, (2) temperate species in tropical environments, and (3) species behaviourally and physiologically misaligned with pastoral environments. }, issn = {1176-5283}, author = {Asher GW and Pearse AJ} } @conference {41287, title = {Feed intake capacity in Holstein-Friesian cows which differed genetically for body weight}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {207-209}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {The feed intake capacity (FIC) of pregnant, non-lactating Holstein-Friesian cows, selected for either high (H) or low (L) breeding values for live weight (LW), was measured when fed to appetite on hay (7.5 MJ ME/kg DM in 1998) and on pasture (11.1 MJ ME/kg DM in 1999). The H cows were heavier than the L cows in both years (546 v 482 kg; 540 v 464 kg in years 1 and 2 respectively), and the H cows ate significantly (P<0.01) more feed than the L cows in both years (12.5 v 11.1 kg hay DM, and 13.1 v 11.6 kg pasture DM per day in years 1 and 2 respectively. Regression analysis showed that for each 100-kg increase in LW, daily DMI per cow increased by 1.43 and 1.81 kg respectively in 1998, and 1999. Regression analysis of the data after conversion into log10 , showed that DMI was proportional to LW0.66 and LW0.65 in 1998 and 1999 respectively. These results indicate that the genetically heavier cows ate more DM than the genetically lighter cows. Nevertheless, the difference between maintenance costs and FIC (or "net" FIC) may be similar for both strains, so that the smaller intake of the lighter cows does not disadvantage their productive capacity. }, issn = {1176-5283}, author = {Caicedo-Caldas A and Lemus-Ramirez V and Holmes CW and Lopez-Villalobos N} } @conference {41247, title = {Ferrets as vectors of bovine Tb in New Zealand: a review}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {60-63}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Feral ferrets (Mustela furo) are a serious pest of agricultural importance because they transmit bovine tuberculosis (Mycobacterium bovis ; Tb) to domestic livestock. They therefore pose a significant risk to New Zealand{\textquoteright}s international trade in dairy, beef and venison products The most likely route of infection to ferrets is oral, through killing and eating infected prey or scavenging infected carrion (particularly possums). Indeed, the prevalence of Tb in ferrets is positively correlated with possum abundance and infected possums. Male ferrets have a higher prevalence of Tb than females, and adult ferrets have higher prevalence than juveniles. It is still not clear whether Tb can cycle independently in feral ferrets in the absence of external (non-ferret) sources of infection (i.e., {\textquotedblleft}maintenance hosts{\textquotedblright}) or whether the disease is simply {\textquotedblleft}spillover{\textquotedblright} infection from other wildlife populations (predominantly possums). Available evidence suggests that ferrets are more likely to be spillover than maintenance hosts in most habitats in New Zealand. However, several aspects of the epidemiology of Tb in feral ferrets, and the ecology of feral ferrets, need to be investigated in order to resolve this debate.}, issn = {1176-5283}, author = {Byrom AE} } @conference {41257, title = {The film crew{\textquoteright}s here! Are you ready?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {86}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {The Reporter/Directorcontrols the story line and {\textquoteleft}angle{\textquoteright} (direction) the story will follow. They question the {\textquoteleft}talent{\textquoteright} (the scientist) and decide on what {\textquoteleft}shots{\textquoteright} (pictures) will be used to illustrate the words in consultation with director of photography. The Director of Photography/Camera Operatorwill make sure you are in focus, set up the framing of the picture and lighting and control the picture quality. The Sound Operatorwill capture all the sound, from interviews to lambs bleating and computers that go {\textquoteleft}bing{\textquoteright}. The sound operator controls sound quality - they don{\textquoteright}t like airport flight paths or lawnmowers! These people are mostly {\textquoteleft}freelancers{\textquoteright}. That is, they usually don{\textquoteright}t work for the actual film/production company. The standard filming day is 10 hours plus a 45-minute lunch break. Many of them like coffee and most smoke. }, issn = {1176-5283}, author = {Tompkins NB} } @conference {41260, title = {Genetic studies of resilience of Romney sheep to nematode challenge in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {92-95}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {"Resilience" in sheep can be defined as the ability to withstand nematode challenge, and to maintain acceptable health and productivity, with minimal reliance on anthelmintic treatment. One heritable component trait is Total Drench Requirement (TDR), which is measured in lambs managed on a regime of "drench-on-demand" (where Trichostrongylus and Ostertagia are the predominant nematode genera in New Zealand sheep). A breeding experiment was established in 1994, selecting for increased resilience in Romney lambs. Currently, breeding ewes in the experiment are subdivided between Ballantrae, where four genetically equivalent sub-groups graze separate farmlets year-round, under Non-Chemical versus Conventional management (AgResearch{\textquoteright}s Low-Chemical Farming Systems Programme), and Wallaceville, where an Elite Resilient line was re-established in 1999 alongside the Control Faecal Egg Count (FEC) line. Selection responses up to 1999/00 in the Elite Resilient-line lambs (relative to the Control line) included a 27\% greater post-weaning weight gain (GAIN: Dec. to Apr.), a 0.48 unit reduction in dags, and a 45\% reduction in TDR (Dec. to Apr.). A favourable genetic correlation (-0.54) was recorded between TDR and GAIN in lambs, whilst that between TDR and log FEC was -0.17 (not significant). Mean autumn weights in lambs at Ballantrae were 5.8 kg (18\%) lower in the Non-Chemical than Conventional treatment groups (P<0.01). Through intense genetic selection, 51\% of Elite-line ram lambs are now resilient enough for low-chemical or organic production systems. }, issn = {1176-5283}, author = {Morris CA and Bisset SA and Vlassoff A and Mackay AD and Betteridge K and Alderton MJ and West CJ and Devantier BP} } @conference {41252, title = {Headlines can be Headaches}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {78-79}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {With some alarm the author read the headline {\textquotedblleft}Scientists Boring{\textquotedblright} in Rural News in November 1997 (Keating, 1997). Fortunately for the New Zealand Society of Animal Production the page header was {\textquotedblleft}Grassland Conference{\textquotedblright}. The article, which started {\textquotedblleft}Agricultural scientists are boring the pants off dairy farmers {\textellipsis}{\textquotedblright}, gradually went further down hill explaining that {\textquotedblleft}The [Ruakura Farmers] conference was {\textquoteleft}old and outdated, inflexible and not meeting their needs. Lectures were long boring and often too theoretical{\textquoteright}{\textquotedblright}. The article{\textquoteright}s centrepiece claimed {\textquotedblleft}Farmers agreed it was better to have a good presenter talk about somebody else{\textquoteright}s research than to have a poor presentation from a good scientist.{\textquotedblright} The contracted papers that follow this introductory paper indicate steps that members could take to remedy this situation. First and foremost, the reader will note that the papers in this contract are written in layman{\textquoteright}s language, outside the guidelines for scientific writing. }, issn = {1176-5283}, author = {Scobie DR} } @conference {41255, title = {How to get an article published in print media}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {84}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {There are levels of exclusivity and there are ways to maximise the impact of your article or idea. I{\textquoteright}m not suggesting you attempt to seek money in exchange for your involvement in the article, but you can maximise its impact and uptake by offering a number of different papers their own exclusive angle.}, issn = {1176-5283}, author = {Leggett TW} } @conference {41274, title = {The importance of an accurate estimate of net endogenous loss of magnesium in ruminants}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {156-159}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Attempts to scale up to dairy cattle from a model of magnesium (Mg) metabolism in sheep has shown more rapid reduction in plasma Mg concentration than has been observed in practice when rates of Mg absorption are reduced. Nutrient requirement tables of agriculture research council (1980) provide an estimate for endogenous loss of 3 mg/kg LW/d and, because of the paucity of data, apply this value to sheep and cattle. Such a value represents over 40-50\% of the daily requirement for Mg of a typical New Zealand dairy cow even in early lactation. Moreover, the estimate is represented as a constant function of body weight. Net absorption of Mg in ruminants occurs largely in the rumen, but there is recent evidence suggests significant absorption occurs in the large intestine. Therefore, endogenous secretions into the gastrointestinal tract will be available for re-absorption in the large intestine. Under these circumstances it is important for modelling purposes to have an understanding of the true secretion of Mg from which net endogenous Mg losses and, therefore, maintenance needs can be predicted with accuracy. This paper argues from evidence in the literature that net endogenous losses of Mg are unlikely to be a constant. True secretion could be up to 15 times the net endogenous loss because of potentially large exchanges of Mg in different regions of the alimentary tract, which are probably a function of plasma Mg concentration. The case is made a new approach to estimation of maintenance requirement of Mg. }, issn = {1176-5283}, author = {Laporte JA and Bell ST and Sykes AR} } @conference {41270, title = {The influence of reproductive status on pituitary gland function in seasonally anoestrous red deer hinds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {141-143}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Changes in pituitary responsiveness to exogenous hypothalamic hormones were assessed during seasonal anoestrous in dry, pregnant and lactating hinds. Of the fifteen adult red deer hinds monitored, five were non-pregnant, five had their calves removed immediately after birth, and five suckled their calves. All hinds were given a single i.v. injection of hypothalamic releasing hormones (5mg each of GnRH, GRF and TRH) on four occasions between Nov/Dec (10 days prior to calving) and March. The pituitary response was determined from changes in plasma concentrations of LH, growth hormone, and prolactin in samples obtained by jugular venepuncture at 0, 15 and 30 min after injection. Reproductive state significantly (P<0.001) affected LH release with a mean response (over all sample dates) of 1.12 ng/ml in dry hinds compared with 0.85 ng/ml in hinds that had their calves removed and 0.60 ng/ml in lactating hinds. Neither growth hormone (average 5.65 ng/ml) nor prolactin (average 33.9 ng/ml) responses were affected by reproductive status. }, issn = {1176-5283}, author = {Fisher MW and McLeod BJ and Meikle LM and Martin SK} } @conference {41291, title = {Intake, live weight and feed-conversion efficiency of lactating Holstein-Friesian dairy cows which differ genetically in live weight}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {221-223}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {The objective of this study was to measure during mid lactation the effect of live weight on the metabolisable energy intake by cows in two lines of Holstein-Friesians selected for heavy or light mature live weight. Yields of milksolids and intakes of dry matter were estimated during two 3-day faeces collection periods. Live weights were measured once in each period. Intakes of pasture dry matter by individual cows were estimated using the alkane technique. Least-square means for live weight, daily yield of milksolids, intakes of dry matter, intakes of metabolisable energy and feed-conversion efficiency for the heavy and the light line were obtained. Linear regression coefficients of metabolisable energy intake on metabolic live weight and yield of milksolids were obtained. Mean values were 15.0 vs. 15.3 kg of dry matter eaten/cow daily, 532 and 488 kg live weight, 1.58 and 1.55 kg milksolids/cow daily, and 108 and 106 g milksolids/kg of dry matter eaten, for the heavy and the light line respectively. The partial regression coefficient of metabolisable energy intake on metabolic live weight was 0.65 MJME/kg LW 0.75 for both lines, similar to commonly reported values. Both lines had similar feed-conversion efficiencies. These data, from 73 grazing cows, generally support other data, and show that live weight does affect maintenance requirements as expected for cows in the heavy and light live weight lines. But they disagree with previous data because the heavy cows did not have higher intakes.}, issn = {1176-5283}, author = {Tolosa MX and Caicedo-Caldas A and Holmes CW and Lopez-Villalobos N} } @conference {41290, title = {Lactation curves for milk traits, live weight and body condition score for heavy and light Holstein-Friesian cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {217-220}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Two genetic lines of Holstein-Friesian cows divergently selected for heavy and light live weight but with similar genetic merit for farm profitability have been developed at Massey University since 1989. The objective of this experimental project was to evaluate differences in production, fertility and feed efficiency between the two lines when they are managed on grazed pasture and submitted to a seasonal system of reproduction. This paper describe the shapes of the lactation curves for yields of milk, fat and protein, live weigh and body condition score of the two lines using the gamma function. Parameters of the gamma function for each of the traits were estimated for each of 84 cows using daily yields of milk, fat and protein and weekly measurements of live weight and body condition scores recorded during the production season 1998-99. Live weights and body condition scores of mature heavy and light cows at calving were 495 and 436 kg and 4.7 and 4.8 units, respectively. Respective values for first-calving cows were 397 and 352 kg live weight and 4.9 and 4.9 units of body condition score. Peak yields of milk, fat and protein for mature heavy (27.6 litres, 1.30 kg and 0.90 kg) were higher than for mature light (25.6 litres, 1.21 kg and 0.86 kg) cows but differences were not significant. Peaks of yield occurred between 27 and 31 days after calving with no significant differences between lines of cows. There were no significant differences between lines for changes in body condition score and persistency of milk, fat and protein production during lactation of mature cows. Compared to mature cows, first-calving cows had lower peak yields of milk, fat and protein. First-calving light cows were the most persistent and maintained the highest body condition score during lactation. Total predicted yields of milk, fat and protein for mature heavy (4,048 litres, 194 kg and 133 kg) were not significantly different from those for mature light (3,774 litres, 182 kg and 127 kg) cows. These results show that there are no significant differences in the shape of the lactation curve for heavy or light mature cows, but first-calving light cows maintained higher body condition score in late lactation. }, issn = {1176-5283}, author = {Lopez-Villalobos N and Lemus-Ramirez V and Holmes CW and Garrick DJ} } @conference {41243, title = {Lipolytic response of New Zealand and overseas Holstein-Friesian dairy cows challenged with epinephrine}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {48-51}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Sixteen New Zealand Holstein-Friesians (NZ HF) and 15 overseas HF (OS HF) grazing pasture or fed a total mixed ration (TMR) were subjected to an epinephrine challenge during early lactation. A genotype x diet interaction trend (P=0.10) was observed; when grazing, OS HF displayed the greatest glycerol response, with the reverse occurring on TMR. No genotype or diet differences were observed for the glycerol or non-esterified fatty acid response. Dairy cows of both genotypes fed TMR produced a glucose response 31\% greater than both genotypes grazing pasture. These preliminary results suggest that genotype x diet-induced differences in the rate of lipolysis may occur in Holstein-Friesians during early lactation. These differences may be a function of small differences in energy balance. Feeding TMR was associated with a greater glucogenic response to epinephrine, which probably resulted from greater hepatic reserves of glycogen or simply a greater energy demand by the mammary gland. }, issn = {1176-5283}, author = {Kolver ES and Roche JR and de Veth MJ and Mackle TR} } @conference {41275, title = {Magnesium endogenous loss as a function of plasma magnesium concentration rather than a constant allows better development of magnesium models in ruminants}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {160-163}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {In the course of adapting an existing sheep model of magnesium metabolism for use with lactating dairy cattle it was found that the model failed to predict plasma magnesium concentrations in agreement with experimental data after scaling the model for animal size dependent parameters. An inspection of the model indicated that faecal endogenous Mg loss and Mg absorption from the hindgut were the model components requiring further development. Pooled data from Mg balance experiments were used to investigate the relationship between plasma Mg concentration, net faecal endogenous Mg loss and the apparent availability of magnesium. A mathematical relationship between Mg intake and faecal Mg output is presented. It was derived from the generalised non-linear case to allow for variability in both apparent absorption of Mg and faecal endogenous Mg loss. A balance trial simulation was carried out in which net faecal endogenous Mg was implemented as a linear function of plasma Mg concentration. The results of this simulation were in close agreement with the analysis of pooled balance trial data and suggest that net faecal endogenous Mg loss should be applied to the model as a function of plasma Mg concentration. In fact net faecal endogenous Mg loss is not useful in modelling since it is the net result of a true Mg secretion function being subject to reabsorption in distal regions of the tract. Post rumen magnesium exchanges are examined in the model by implementing net Mg exchanges in the small intestine and hindgut as separate secretion and absorption processes. The difficulties in isolating the true secretion and absorption functions in the hindgut are discussed in conjunction with an initial estimate of these functions. In the modified model the incorporation of a variable endogenous Mg secretion dependent on plasma magnesium concentration provides an additional mechanism for magnesium homeostasis which is sufficient to allow the model to scale between sheep and cattle. }, issn = {1176-5283}, author = {Bell ST and Laporte JA and Robson AB and Sykes AR} } @conference {41272, title = {Magnesium supplementation of lactating dairy cows in the summer and autumn}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {148-151}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {A series of three trials were established with 188 lactating dairy cows which were supplemented daily with either 0, 10 or 20 g Magnesium (Mg) during 18 weeks from January to May. Cows in each trial were allocated to treatments randomly in a cross-over design with each treatment lasting 2 weeks. This design was replicated three times during the 18 weeks. There was no treatment effect on serum Mg or milksolids (MS) production, (0.82, 0.82 \& 0.83 mmol/l or 0.78, 0.79 \& 0.77 kg MS/cow/day for 0, 10 \& 20 g Mg, respectively; averaged across all trials) and there were no farmlet-by-treatment interactions. Based on visual assessments of pasture intakes and pasture mineral analysis, mean pasture Mg intakes during all three trials ranged from 23 to 35g Mg/cow/day (SEM 1.14). Urine Mg-creatinine ratio of 50 cows during Trial 3 indicated that the urinary Mg concentration increased linearly with increasing dietary Mg (1.38, 1.87, 2.01 for the 0, 10 and 20 g treatments, respectively; SED 0.175). Trial three results suggest that Mg surplus to requirement was being voided by the cow and that it is unlikely that even at the higher stocking rates, a milk production response to Mg supplementation will occur in the summer/early-autumn period when Mg in diet is >0.18\%. }, issn = {1176-5283}, author = {MacDonald KA and Penno JW and Verkerk GA and Jago J and Dow BW} } @conference {41269, title = {Managing fertility in the New Zealand dairy herd}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {135-140}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Effective mating management remains crucially important to pastoral milk production systems in New Zealand (spring calving or autumn calving). The incidence of most diseases has decreased since the 1940s, but infertility, especially the {\textquoteleft}anoestrous problem{\textquoteleft}, has increased despite increased use of hormonal treatments and in association with genetic selection for increased yields of milk. The regular need to treat a high proportion of cows with hormones because they are not cycling at the start of mating should be seen as a sign of mismanagement in the system (genetics, health or feeding). {\textquoteleft}Good herd management{\textquoteleft} should be used to achieve good fertility with minimal use of hormone treatments; this will include: -good prevention and control of all diseases; all heifers must reach target live weights and puberty at 12 months; all cows must be at BCS 5 at calving, and be fed generously in early lactation; excellent heat detection must be maintained for the entire AI mating period; infertile cows must be culled, and fertility included in the Breeding Worth. These aspects of {\textquoteleft}good management{\textquoteleft} must be seen as essential factors in the maintenance of good herd welfare, and in the sustainable production of the high quality, clean and green dairy products required by the world markets. A number of commercial herds are showing that good fertility and good productivity can be achieved with minimum use of hormone treatments, with present-day cows. However, for some strains of cows, good feeding management may be impossible on a diet of grazed pasture. }, issn = {1176-5283}, author = {Holmes CW} } @conference {41259, title = {The media release}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {90-91}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Most important in the process of releasing many science stories is the media release. A clear and simple statement of facts in the form of a media release will reduce the errors in the final story. It provides the opportunity for input from scientists, colleagues, collaborators, managers and the all-important investors (who may not want the story or their involvement released). The media release could also be directly circulated to Members of Parliament or Ministers of the Crown, advisory committees and other scientists and non-scientists within the organisation including members of the board of directors. The help of a journalist to translate it into layman{\textquoteright}s language will also increase the chances of publication {\textellipsis} }, issn = {1176-5283}, author = {Scobie DR} } @conference {41288, title = {Milk yield, prolactin and IGF-1 in cows which calve in Autumn; preliminary report}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {210-212}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {The objective of this study was to investigate causes of reduced peak milk yield of autumn-calving cows. This experiment is part of a study that is comparing autumn- and spring-calving systems. Two groups of 17 multiparous, Friesian cows that had calved between April 1 and May 6 were fed either ad libitum on grazed pasture (G), or restricted pasture (10kg DM/cow/day) supplemented with maize silage (6kg DM/cow/day) (G + MZ) for a period of 21 days. Milk yield by cows on G increased by 6.2 litres over the 21-day period and was significantly higher (P< 0.01) than the yields of cows on G + MZ. Milk prolactin concentration had no significant association with milk yield. There were higher average plasma concentrations of IGF-1 in the G group (range 104-140ng/mL vs. 95-107ng/mL) that corresponded to higher average milk yields but IGF-1 concentration had no significant association with milk yield. Milk yield and milk prolactin concentration were negatively associated with condition score and plasma IGF-1 concentration was positively associated with condition score. }, issn = {1176-5283}, author = {Wrigley J and Holmes C and Lopez-Villalobos N} } @conference {41296, title = {Modelling the impact of milking frequency on lactation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {239-240}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Increasing milking frequency from the usual practice of twice-daily can enhance milk production and, thus, may be profitable in high-intensity dairy production systems. A decrease of milking frequency to once-daily decreases yield but may be used to alleviate nutritional stress, to conserve cow condition, or simply as a lifestyle choice. Published values in the literature indicate that reducing milking frequency from twice daily to once daily decreases yield by 7{\textemdash}34\%, and increasing milking frequency from twice daily to thrice daily increases yield by 7{\textemdash}20\% (Davis et al., 1999; Stelwagen, 2001). Additionally, milking frequency can influence the rate of decline in post-peak production in cows (Stelwagen, 2001). In order to further understand and quantify the manner in which milking frequency affects lactation, a mechanistic mathematical model of mammary function has been developed (Vetharaniam, Davis, Soboleva, Shorten \& Wake, Unpublished), based on mechanisms presented by Davis et al. (1999). As well as allowing analysis of the effect of milking frequency, this model also facilitated the exploration of some of the pathways through which nutrition influences mammary gland development (Davis et al. 2001). }, issn = {1176-5283}, author = {Vetharaniam I and Davis SR and Soboleva TK and Shorten PR and Wake GC} } @conference {41295, title = {Modelling the impact of nutrition and genotype on lactation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {237-238}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Dairy cows grazed on pasture experience variation in their nutritional status during lactation, as both pasture quality and availability vary seasonally. This has both immediate and long-term consequences on cow performance. Acute effects of nutrition are related to availability of nutrients for milk secretion, and are manifested in day-to-day variation in milk yields. Of further importance are the chronic effects of nutrition, which act on the development of the mammary gland, impacting on the persistency of lactation. Typically, cows in a New Zealand, pasture-grazing environment exhibit a decline in milk yield of around 10\% per month, after peak lactation, whereas cows fed a concentrate diet in Northern Hemisphere systems show declines of less than 4\%. Post-peak declines in milk yield are associated with a proportional and permanent decline in the number of secretory cells in the udder, and this decline is modulated by nutrition (Davis et al., 2000). Quantifying the milk-yield response of a cow to different nutritional regimes is useful from a breeding and selection point of view, but on its own does not give insight into which pathways are likely to be affected by nutrition, nor does it explain the origin of differences in responses between cows. To this end, mechanistic mathematical models that reflect the underlying biology of the udder are particularly useful. }, issn = {1176-5283}, author = {Davis SR and Vetharaniam I and Upsdell M and Kolver ES and Pleasants AB} } @conference {41244, title = {Monitoring adrenal activity in dairy cows under various feeding regimens using faecal glucocorticoid metabolites}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {52-55}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Adrenal activity in cattle can be measured by changes in plasma glucocorticoid concentrations. Cows treated with synthetic adrenocorticotrophic hormone (ACTH) to stimulate the adrenal cortex exhibited elevated plasma cortisol concentrations for 4-5h. Concentrations of faecal glucocorticoid metabolites (FGM) peaked between 8-9.5h after ACTH treatment, 2.5 fold higher than basal (P<0.05) and remained elevated for 13h (range, 11.1-16.1h). Faecal glucocorticoid concentrations were monitored in two strains of Holstein Friesian (HF) dairy cows farmed in New Zealand under two systems: NZ pastoral and North American concentrate-based. The overseas (OS) and New Zealand (NZ) HF were fed a pasture-based diet (Grass) or a total mixed ration (TMR) throughout lactation. Faecal samples were collected on four occasions during lactation. Faecal glucocorticoid concentrations of the cows fed Grass were consistently higher (P<0.05) than cows fed TMR. There was also a significant genotype effect; FGM concentrations of the NZ HF cows were higher than OS HF cows (P<0.05). In a separate study, no obvious trends were evident in FGM in NZ HF grazing pasture at three stocking rates (2.2, 3.2, 4.3 cows per hectare). Measuring FGM can be used to monitor acute adrenal activity in cows, but is more difficult to interpret as a measure of chronic stress. }, issn = {1176-5283}, author = {Morrow CJ and Kolver ES and MacDonald KA and Verkerk GA and Matthews LR} } @conference {41236, title = {Nutraceuticals}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {27}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Nutraceuticals can be defined as {\textquotedblleft}products isolated or purified from foods and generally sold in medicinal forms not usually associated with food, and have demonstrated physiological benefits or provides protection against chronic disease{\textquotedblright}.}, issn = {1176-5283}, author = {Keeley R} } @conference {41268, title = {Nutrition and lameness in pasture-fed dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {128-134}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {This review examines the potential for nutritional factors to contribute to the high incidence of foot lameness in New Zealand pasture-fed dairy cattle. Spring and autumn temperate pastures are highly digestible, contain high concentrations of rumen degradable protein and the effectiveness of neutral detergent fibre (NDF) may be too low to support optimum rumen function. Risk of laminitis and lameness increases with chronic ruminal acidosis and there is evidence for sub-optimal rumen pH in New Zealand cows. Inadequate uptake of trace elements and minerals may compromise hoof health, and there is evidence for lameness associated with the ingestion of high concentrations of anti-nutritional compounds. The clinical examination of lameness in pasture-fed cows must incorporate an investigation of the nutritional status of the cow in addition to environmental, management and animal factors. }, issn = {1176-5283}, author = {Westwood CT and Lean IJ} } @conference {41233, title = {Opportunities for enhancing the delivery of novel forage attributes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {16-19}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Allocating spatially separated forage choices to grazing animals overcomes constraints inherent in mixed pastures and sustainably delivers the required diet composition, satisfies their desire for mixed diets, and so offers a simple way to enhance the delivery of the benefits of current and novel forage attributes. Sheep offered grass and clover in this way increased daily dry matter intake by 265 g/day (25\%, P<0.05) compared with conventional pasture and sustained 60-70\% clover in their diet. Milk production by cows was boosted by 11\% (2.4 kg/cow/day, P<0.01).}, issn = {1176-5283}, author = {Cosgrove GP and Parsons AJ and Marotti DM and Rutter SM and Chapman DF} } @conference {41239, title = {Optimal utilization of genetic resources in aquaculture}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {35-37}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {This paper uses a vertically integrated salmon farming company as a case study to describe how quantitative genetics and decision support optimisation tools have been used in an aquaculture breeding programme. The complex tasks of maximising genetic progress while managing genetic diversity and avoiding inbreeding are considered at two levels. The first level relates to the management of a nucleus breeding structure for which long term genetic progress and management of genetic diversity are the primary objectives. The second level relates to the tactical selection among available broodstock candidates and their mating to avoid inbreeding. The importance of both effective data management systems and practical implementation of theoretical genetic principles is emphasised.}, issn = {1176-5283}, author = {Amer PR and Jopson NB and Dodds KG and Symonds JE and Hills J} } @conference {41246, title = {Possums as vectors of Tb in livestock}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {57-59}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Bovine tuberculosis (Tb) is the most important disease of livestock in New Zealand, and it occurs in cattle and deer herds at relatively high incidences by international standards. Brushtail possums are the major wildlife vector and maintenance host of Tb in New Zealand, and their infection is the single greatest barrier to the eradication of Tb from New Zealand livestock. The control of infected populations of possums underpins attempts to eliminate the disease from livestock. Possum populations infected with Tb occupy about 24\% of New Zealand, which is also where about 75\% of the reactor herds and Tb-infected cattle occur. Possums with Tb often exhibit lesions in their lungs and external lymph nodes and infection in these sites appears to be involved in the transmission of the disease to other possums. The mode of transmission of Tb from possums to livestock is unproven, but it is thought to occur when inquisitive stock encounter dying possums. }, issn = {1176-5283}, author = {Coleman JD} } @conference {41282, title = {Postpartum anoestrous interval and metabolic changes in heifers supplemented with pasture prepartum}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {188-191}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {The aim of this study was to determine whether supplementation with pasture from 6 weeks before calving would alter the postpartum anoestrous interval (PPAI) in heifers calving with low body condition score (BCS). Metabolic hormones and metabolites were measured during the pre- and postpartum period. Forty Friesian heifers were managed during the last five months of gestation to achieve a BCS (1-10) of 4.0 (restricted; R; n=27) or 5.0 (fully fed; FF; n=13) by 6 weeks prepartum. One group with low BCS then received pasture ad libitum until calving (restricted + fully fed; R+FF; n=12). Live weight (LW) and BCS were assessed weekly. Blood samples were collected weekly from 10 weeks prepartum to 10 weeks postpartum to measure glucose, urea, non-esterified fatty acids (NEFA), betahydroxybutyrate (BOH) and cholesterol content. The patterns of metabolites measured differed between groups at different times, future work to investigate the relationship these profiles and PPAI would be of value. The percentage of cows cycling as measured by an elevated milk progesterone concentration was 69\%, 75\% and 8\% for FF, R+FF and R groups, respectively. Fully feeding heifers, with low condition score, 6 weeks before calving decreased PPAI when compared to heifers receiving restricted feeding. }, issn = {1176-5283}, author = {Chagas LM and Morgan SR and Gore PJS and Clark BA and Verkerk GA} } @conference {41285, title = {Potential benefits from new reproductive technologies in commercial dairy herds; a case study simulation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {199-202}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {New reproductive technologies may provide the possibility to derive the egg component of embryos for dairy cow replacements from only an elite proportion of the dairy herd, or from heifers or calves, thereby creating opportunities for greater genetic gain. Using modelling, four possible selection strategies in two case study herds were compared over 10 years at annual replacement rates of 15, 20 and 25\%. In the different strategies, replacement calves were bred from: (1) AB bull + all herd cows, {\textquoteleft}status quo{\textquoteleft} vs (2) AB bull + only the top 25\% of herd cows vs (3) AB bull + the top 100\% of maiden heifers vs (4) AB bull + the top 100\% of heifer calves. Assumptions used included (1) an average bull breeding worth (BW) of $135, gaining by $5 per year. (2) A {\textquoteleft}high BW herd{\textquoteleft} average BW of $62 (almost in the top 10\% of all New Zealand herds). (3) A {\textquoteleft}low BW herd{\textquoteleft} average BW of $32 (nearly in the bottom 10\%). The model predicted that rate of herd genetic gain increased with replacement rate. The low BW herd gained more than the high BW herd using any of the strategies because it started from a lower base. The BW of the 2 herds converged over 10 years and this effect increased with selection pressure. After 10 years, BWs of 150 and 149 were predicted for the high and low BW herds respectively by using eggs from calves as in Strategy 4 above. This compared with Strategy 1 where herd BWs at year 10 were 130 and 120 respectively. }, issn = {1176-5283}, author = {Smeaton DC and Vivanco HW} } @conference {41249, title = {Potential transmission routes of rabbit haemorrhagic disease: Consequences for epidemiology of RHD in wild rabbits}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {68-70}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Rabbit haemorrhagic disease (RHD) was released in New Zealand in the spring of 1997 and has subsequently spread naturally and with the assistance of people to most, if not all, rabbit populations in the country (Parkes et al., 2001). The disease and its impact on rabbit numbers have been described for the initial epidemics in Otago rabbit populations (O{\textquoteright}Keefe et al., 1999), in ongoing cross-sectional studies at 10 sites in Canterbury and Otago (Parkes et al., 2001), and in a single longitudinal study in the Manawatu (Henning et al., 2000). In this paper we wish to discuss alternative ways the RHD virus (RHDV) might be transmitted to rabbits, report on the evidence from field and pen trials on various transmission routes, and speculate on the possible routes that fit the observed epidemiological data from our study sites in Otago and Canterbury. }, issn = {1176-5283}, author = {Parkes JP and Norbury GL and Heyward RP and Heath ACG} } @conference {41297, title = {Prediction of ruminal pH of dairy cows fed pasture}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {241-243}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Rumen pH as low as 5.6 has been reported in cows fed highly digestible pasture, however, incidences of sub-acute acidosis have not been well documented and there are no easy or reliable means for farmers to measure ruminal pH. This study collated animal and dietary parameters (81 treatment means), from 20 studies of lactating dairy cows fed pasture, to evaluate the relationship between ruminal pH and animal parameters, and identify suitable predictors of ruminal pH. Mean ruminal pH (5.6-6.7) was negatively correlated (P<0.05) with total volatile fatty acid concentration, milk yield, microbial N flow from the rumen, milk protein yield, milk fat yield, total non-structural carbohydrate content and acid detergent fibre content of the diet. No single dietary parameter, or group of parameters, was able to adequately predict ruminal pH. The increase in microbial nitrogen flow, milk, and milk fat production as ruminal pH decreased below 6.2 suggested that the performance of cows fed high quality pasture was not limited when mean ruminal pH decreased to 5.8. This implies that dairy cows fed pasture can tolerate a lower ruminal pH before sub-acute acidosis occurs than when forage-concentrate diets are fed. }, issn = {1176-5283}, author = {de Veth MJ and Kolver ES} } @conference {41229, title = {Presidential Address 2000: Animal products contribution to New Zealand{\textquoteright}s wealth}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {1-3}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {The 60th anniversary of the New Zealand Society of Animal Production is an appropriate occasion on which to acknowledge the massive contribution that animal products have made to the New Zealand economy. Maori used products from kiore and dogs as well as wildlife and fish. The first Europeans started with whaling and sealing, then moved to wool production before freezers on ships opened up world meat markets. More recently dairying and fishing have boomed and chicken, meat and egg, pork and deer industries have arisen. Add goat, ostrich, mussels, possums etc and you have a long, varied list of species and products. However it is the products from grazing sheep and cattle that have provided the bulk of New Zealand{\textquoteright}s export earnings over the last one hundred and fifty years. They continue to dominate to this day {\textellipsis} }, issn = {1176-5283}, author = {Bray AR} } @conference {41245, title = {Progress in controlling Bovine Tuberculosis in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {56}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Bovine tuberculosis (Tb) is the greatest disease problem facing the New Zealand cattle and deer industries. During the 1999/00 financial year, 1,212 (1.67\%) cattle and deer herds were infected at some point, eight times the international accepted level for freedom from infection. The source of infection for cattle and deer herds is predominantly wild animals, particularly possums and in some parts of the country, ferrets. Areas where wild animals act as a source of Tb infection for cattle and farmed deer are classified as Vector Risk Areas (VRAs). Currently 33\% of New Zealand{\textquoteright}s land area is classified as VRA. Reducing the density of Tb vectors in VRAs, to minimise contact with cattle and farmed deer, is therefore a core requirement for controlling bovine tuberculosis in New Zealand {\textellipsis} }, issn = {1176-5283}, author = {Livingstone P} } @conference {41254, title = {Is Public Relations just Spin Doctoring or is it Reputational Risk Management?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {82-83}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Public Relations has been described as {\textquoteleft}making the crap credible{\textquoteright}. Many would argue that promoting biotechnology and genetic engineering research in today{\textquoteright}s political environment definitely falls into this category. Indeed there may be a very thin line between promoting or defending such research. While such work may be labelled as {\textquoteleft}public relations{\textquoteright} by the traditionals, or {\textquoteleft}spin doctoring{\textquoteright} by the more cynical, a more valid and correct label for it would be {\textquoteleft}reputational risk management{\textquoteright}.}, issn = {1176-5283}, author = {Fernandez F} } @conference {41256, title = {Radio Interviews}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {85}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {The author is not a trained journalist, merely a farmer given the opportunity to get behind a microphone twice a week and produce a live show that runs an hour over lunchtime each Tuesday and Thursday, which is then replayed the following morning between 6 to 7am. The show is called {\textquoteleft}The Cockies Hour{\textquoteright} and is on Central FM, which broadcasts from Woodville to Hastings. The station is a commercial station, which has a few constraints and differences from a non-commercial station such as the state broadcaster, National Radio. However, both have many similarities.}, issn = {1176-5283}, author = {Wynn-Harris S} } @conference {41283, title = {Relationship between bulk milk urea nitrogen and reproductive performance of New Zealand dairy herds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {192-194}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {New Zealand dairy cows grazing lush spring pasture have relatively high plasma urea nitrogen levels as a consequence of the high soluble crude protein content of this rapidly growing pasture. The elevated plasma urea levels have been implicated as a cause of poor reproductive performance in dairy herds. The aim of this trial was to determine if the bulk milk urea nitrogen levels (BMUNs) collected during the period from calving and through mating were related to the reproductive performance of the herds. Bulk milk samples were collected twice a week from 127 farms during the spring of 1998. The farms were suppliers of the NZ Dairy Group and Kiwi co-operatives. Reproductive performance data was collected from all herds. BMUNs were determined spectrophotomically using Sigma blood urea nitrogen kits. The twice-weekly BMUNs were averaged for each farm and these weekly mean values were centred on the nominated week of mating (W=+1) for the individual farms. There were significant among-farm differences in BMUNs with individual weekly farm values ranging from 5.4 to 26.8 (mg/dl) and the mean (W-3 to W+5) value for farms ranging from 9.6 to 18.8 (mg/dl). There were significant between farm differences in reproductive performance. The percentage of cows submitted for AI in first 3 weeks of mating (\%SR21) ranged from 29.9 to 95.3\%. The percentage of SR21 cows conceiving to that AI (\%Preg1) ranged from 39 to 98.6\% and the percentage of all cows in the herd pregnant by the end of mating (\%Pregall) from 44.9 to 98.4\%. There was some indication of a relationship between reproductive performance and BMUNs in that the change in BMUN level from W-3 to W+5 was significantly correlated within geographic zones with \%SR21 and \%Pregall, correlation coefficients being 0.36 (P=0.013) and 0.37 (P=0.010) respectively. The corresponding correlation for \%Preg1 was only 0.21(P = 0.15). Thus farms for which BMUNs rose over the period W-3 to W+5 had higher reproductive performance than those in the same zone, which showed a fall. However, this accounted for very little of the overall variability. Farms were ranked on their reproductive performance and the average weekly BMUNs for the farms in each quartile calculated. There was no difference in the pattern of BMUNs for the different quartiles of each reproductive parameter. Thus, the measurement of BMUNs would appear to be of little value as an indicator or predictor of reproductive performance. }, issn = {1176-5283}, author = {Smith JF and Beaumont S and Hagemann L and McDonald RM and Peterson AJ and Xu ZZ and Duganzich DM} } @conference {41284, title = {Relationships between, milk production, nutrition and reproduction in benchmark herds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {195-198}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Inter-relationships between nutrition, milk production and reproduction in dairy cows were investigated in dairy herds with previous high reproductive performance. Ten herds were selected as {\textquoteleft}benchmark{\textquoteleft} farms from one area of the Waikato. Pasture and supplement intakes, and milk production were monitored on a herd basis. Bulk milk samples were taken weekly from calving through to the first three weeks of mating and assayed for levels of progesterone, urea nitrogen and b-hydroxybutyrate (BOH). Pre-mating oestrus, mating (AI) and pregnancy data were recorded. All data was expressed in relation to the planned date of mating (PSM) for each farm. Significant between farm differences were detected in all the reproductive parameters but there was no effect of supplement feeding. The mean proportion of cows cycling at PSM was 65.6 {\textpm} 3.3\% (range 50.5 to 81\%).The mean proportion of cows pregnant to AI at PSM + 3 weeks was 51.3 {\textpm} 2.1\% (range 43 to 61.5\%); at PSM + 6 weeks the mean was 74.5 {\textpm} 3.3\% (61 to 89.5\%); at PSM + 9 weeks it was 84.7 {\textpm} 2.2\% (74.9 to 91.6\%) and at PSM + 12 weeks it was 91.3 {\textpm} 1.2\% (85.6 to 95.4\%). Bulk milk progesterone rose linearly from a mean of 0.5 ng/ml at 8 weeks before PSM to 5.0 ng/ml at PSM and to 6.0 ng/ml three weeks later. The difference between farms at PSM ranged from (2.1 to 7.1 ng/ml). While the pattern of increase in bulk milk progesterone tended to mimic the overall pattern of oestrus activity, there was no relationship in the ranking of farms for these parameters at any time. Bulk milk BOH showed no consistent pattern over the period of measurement and levels ranged between farms in any one week from 0.01 to 0.05 mM. Bulk milk urea nitrogen concentration also showed little change on average (7.25 mM) over the pre-mating and mating periods. The significant between-farm differences in these bulk milk parameters did not appear to be related to reproductive performance. Metabolic indicators measured in bulk milk samples appear of little value for predicting reproductive performance at herd level. }, issn = {1176-5283}, author = {Smith JF and Verkerk GA and Clark BA and McKay BJ and Duganzich DM} } @conference {41267, title = {Reproductive physiology and management of high-yielding dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {120-127}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {The future efficiency of the dairy industry will undoubtedly be affected by the decline in fertility and reproductive efficiency in modern dairy cows. The cause of the declining fertility is probably a combination of genetic, physiological and management factors that have an additive effect on reproductive efficiency. Milk production per cow has increased and is one factor that is contributing to the problem. In addition to milk production, however, many other equally important factors may be involved. For example, the reproductive physiology of dairy cattle has changed in response to genetic selection for milk production and these changes may require different management strategies. Compared to traditional dairy cows, modern dairy cows have longer intervals to first ovulation, a higher incidence of anoestrus, abnormal luteal phases, lower blood progesterone concentrations, and greater embryonic loss. Reproductive decline can be reversed in dairy cows but a collective effort that includes more intense reproductive management, genetic selection for improved fertility, and new scientific discoveries will be necessary before the problem can be solved. }, issn = {1176-5283}, author = {Lucy MC} } @conference {41279, title = {Resynchronising returns-to-service in anoestrous cows in Victorian dairy herds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {176-179}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Many cows treated for anovulatory anoestrus in Victorian herds which fail to conceive to first insemination also fail to return-to-service 18 to 24 days later. A trial in 16 herds in the Maffra district determined whether treatments to re-synchronise returns-to-service could also increase submission rates for a second insemination in these cows. The 810 Holstein cows initially treated for anovulatory anoestrus provided 691 for inclusion in the study. A previously used CIDRTM device was re-inserted 12 to 14 days after first insemination with injected oestradiol benzoate (1mg ODB), and was removed 7 days later. Some cows received no further treatment (Group 1; n=357); the remainder were each injected with 0.5mg ODB 24h after device removal (Group 2; n=334). Conception rates were similar for the two Groups (1st insem: 29\% vs. 32\%; 2nd insem: 44.5\% vs. 46.4\%). The higher submission rate for synchronised second inseminations in Group 2 (40\% vs. 65\%; P<0.01) meant that the median interval from first insemination to conception was reduced from 42 days (Group 1) to 23 days (Group 2 ; P<0.01); pregnancy rates after 6 weeks of AI were increased from 51.5\% to 59.6\%, respectively (P<0.01). The injection of ODB given after device removal for resynchrony improved the efficacy of treating anoestrous cows in these Victorian herds. }, issn = {1176-5283}, author = {Eagles VE and Malmo J and Macmillan KL} } @conference {41253, title = {Scientists and the media: Attracting and avoiding attention}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {80-81}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {{\textquotedblleft}The public{\textquoteright}s right to know and the scientist{\textquoteright}s duty to inform are essential in a civilised democracy{\textquotedblright} {\textendash} a pompous statement made by Johnstone (2000). The author suspects that, generally speaking, there are two common views among scientists about the media. Most scientists actively dislike the media; some merely mistrust them. Despite that, the author continues to encourage scientists to overcome those views, jump in to the media bath, and talk about their work, their worries, and their hopes. If they fail to do that, others will decide what people should be told about scientific matters. }, issn = {1176-5283}, author = {Johnstone LA} } @conference {41263, title = {The search for quantitative trait loci affecting wool colour}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {104-108}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Farmers have been attempting to breed whiter wool for some time using quantitative and subjective genetic selection based on phenotypic traits. The improvement of wool colour using this form of selection has achieved limited success. The advent of DNA marker maps has introduced the possibility of more directly relating phenotypic and genetic variation. Work presented here has identified a total of ten potential quantitative trait loci (QTL) that are significant at the suggestive level, and one additional QTL that approached this significance threshold that influence wool colour. There have been five putative QTL identified for base colour or challenge colour brightness. Two QTL affecting challenge colour yellowness was identified, while three QTL identified were linked to predictive colour variation. An additional QTL that affected predictive colour has also been mapped to a non-specific location on chromosome 24. Several further key areas of research need to be addressed before the DNA markers can be developed for use in the improvement of wool colour. }, issn = {1176-5283}, author = {McKenzie GW and Maher AP and Dodds KG and Beattie AE and Henry HM and Hickford JGH and Montgomery GW} } @conference {41265, title = {Simulated impacts of new reproductive technologies on the productivity of beef production systems}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {112-115}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {A computer simulation model was developed to explore how new reproductive technologies could improve beef productivity through embryo transfer (ET), sex ratio control and use of small cow breeds pregnant to {\textquoteleft}high growth rate{\textquoteleft} calf genetics. Assumptions were made about conception rates, embryo losses, sex ratios, cow and calf survival, animal weights, and the feed requirements of small and large cows rearing large calves. A range of pregnancy rates from ET (40 to 67\%) were assumed compared to natural mating (67\%) and it was also assumed that a small cow breed, such as a Jersey, could rear calves to similar weights of those from Hereford x Friesian (H x F) cows. Cow efficiency values were derived as the estimated intake of metabolisable energy by the cow plus calf unit per year per kg of calf weaning weight. The model was based on averages with variance information from fieldwork used for @Risk analyses. In the model, H x F cows subjected to the new technologies such as ET (involving synchronised calving) and sex ratio control were up to 9\% more efficient than the {\textquoteleft}status quo{\textquoteleft} mating system. Using a small cow, however, gave gains in efficiency of up to 20\%. These benefits were highly dependent on the assumptions used, in particular ET pregnancy rate and cow and calf losses at calving, all of which, singly or together, above threshold values, could destroy the gains or even create losses in efficiency. }, issn = {1176-5283}, author = {Smeaton DC} } @conference {41232, title = {Tasmanian grass grub - a significant threat to pastoral farming in dryland regions}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {13-15}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Tasmanian grass grub, first recorded in Canterbury in 1920, is now well established in several areas of New Zealand. The adult beetles fly in January and lay their eggs in the soil after mating. After hatching, the larvae live in the soil and construct vertical tunnels from which they emerge at night to feed on and denude pasture plants. The effects of this pest on pasture were estimated by measuring pasture with larval densities ranging from 21-574 m{\texttwosuperior}. Larval infestation significantly reduced pasture mass in a linear fashion by around 5\% per 100 larvae. For example, at one site from July to September, pasture mass Y = -0.816X + 1852, R2 = 0.3; where Y = pasture mass (kg DM per ha) and X = larvae per m{\texttwosuperior}. Losses in stock carrying capacities have been estimated to vary between 0.5 and 5 stock units per hectare depending on the farm carrying capacity and larval damage to pasture, resulting in losses of up to $315 per hectare. }, issn = {1176-5283}, author = {Slay MWA and Fisher MW} } @conference {41293, title = {Toward a predictive model of supplementary feeding response from grazing dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {229-233}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Many experiments have measured the responses of grazing dairy cows to supplementary feeds, but few have studied the reasons for the large differences in responses between experiments. Data derived from two trials, in which supplementary feeds of either maize grain or a nutritionally balancing ration were offered to cows in early, mid, and late lactation in each of spring, summer, autumn and winter, were used to calculate the marginal milksolids responses to supplements. The data set created was subject to multiple regression analysis in an attempt to quantify the effect of the different variables on the magnitude of the response to supplementary feeds. The factor that was of greatest importance was the relative feed deficit (RFD) of the cows measured by the reduction in milksolids yield (kg MS/cow/day) of the respective control groups that had occurred when the restricted feeding treatments had been imposed. Total marginal milksolids responses were greatest when severe feed restrictions, relative to current feed demand, resulted in large reductions in milksolids yield of the control groups. Total marginal milksolids response increased (P<0.01) by 0.9g MS/MJME offered as supplement per 0.1 kg MS/cow/day RFD. Total marginal milksolids responses also declined (P<0.01) by 0.2 g MS/MJME offered as supplement as pasture allowance increased by 10 MJME/cow/day. }, issn = {1176-5283}, author = {Penno JW and MacDonald KA and Holmes CW} } @conference {41241, title = {Will the big birds fly?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {42-44}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Modern ostrich farming in New Zealand commenced in 1994 with importation of eggs. In 1997 the first processing of ostrich meat for the domestic market occurred. By 1999 there were estimated to be 2500 breeding hens, 12,000 chicks and 10,000 rising 1-year-old birds. The current domestic market for ostrich meat is about 100 tonne annually and there has been an increase of 70\% in the last 12 months. About 4000 yearling birds provide meat for the domestic market. Export of ostrich to Europe commenced in 2000. At current prices the limiting constraint is achieving 15 slaughter birds per hen each year. Slaughter birds need to be over 95 kg live weight. Quality of hen nutrition is considered a critical factor influencing embryonic mortality and chick survival. The target rate is being achieved by some farmers, but for this to be an industry average, further developments in breeding hen nutrition and young chick survival will be required.}, issn = {1176-5283}, author = {Thompson KF and Binks S} } @conference {41298, title = {y-glutamyl transpeptidase and amino acid transport for milk protein production in vivo}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {244-247}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Activity of the enzyme g-glutamyl transpeptidase (g-GT) (EC 2.3.2.2) a putative facilitator of amino acid (AA) transport in the mammary gland, increases before lactation and decreases at weaning, suggesting a role in AA transport for milk protein synthesis. The effect of g-GT inhibition by acivicin and supply of cyst(e)ine from N-acetylcysteine (NAC) on mammary AA uptake and milk production was studied in lactating goats. NAC increased (P<0.05) arterial supply of some AA but did not increase arterio-venous difference as a percentage of arterial supply (extraction \%) and did not alter milk protein yield. Acivicin decreased (P<0.05) milk protein yield but this effect was not found when NAC was administered in combination with acivicin. This indicates that NAC, by indirectly enhancing intracellular cysteine, countered the effect of acivicin inhibition, suggesting a role for g-GT in supply of cysteine for milk protein synthesis. }, issn = {1176-5283}, author = {Johnston SL and Roy NC and Davis SR and Tweedie JW and Kitson KE and Lee J} } @conference {41149, title = {Analysis of milk constituents by near infrared and visible light}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {19-20}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Herd testing, in which individual cow{\textquoteright}s production performance is measured, is infrequently carried out in New Zealand with at least a month between tests. A composite sample is collected from each cow and is analysed for fat, protein, and somatic cell count (SCC). The process is time consuming, and provides only a snapshot of these components. To create a more frequent, automated, on-farm system, sensors need to be developed that measure fat, protein, SCC, and other milk components inexpensively and easily. One potential measurement method which could be used in these devices is visible to near infrared (NIR) spectroscopy. The industry currently uses a range of sophisticated machines (Fossomatic, Foss, Hedehusene Denmark) for the determination of milk constituents. These machines homogenise milk and use infrared (IR) spectroscopy in the wavelength range 3500-9600 nm to determine fat, protein, and lactose concentrations. SCC is determined by an integrated flow cytometer. The NIR region (1000-2500 nm) has also been successfully used to determine constituents of milk and milk products (Rudzik \& W{\"u}st, 1998). Any inexpensive, on-line sensor based on NIR spectroscopy should function without the requirement for homogenisation and use low-cost silicon photodetectors, which are sensitive from 400-1100 nm. }, issn = {1176-5283}, author = {Whyte DS and Kunnemeyer R and Claycomb RW} } @conference {41205, title = {Behaviour response of calves to amputation dehorning with or without local anaesthesia}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {234-236}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {This study tested the hypothesis that the expression of some specific behaviours of calves following amputation dehorning is modified by use of local anaesthesia such that their behaviour is similar to calves which were not dehorned, during the period of action of local anaesthesia. The hypothesis was not supported and the behaviour of calves given local anaesthesia was similar to animals dehorned without anaesthesia during the two hours after amputation dehorning and not similar toanimals which were not dehorned. It is possible that the behaviours which were monitored (feeding, rumination, grooming,lying down, ear-flicks, head-shakes, tail-shakes) were not relevant to the pain experienced by calves after dehorning.However, there were significant differences between the behaviour of control animals and those that were dehorned. Thephysical change caused by dehorning and the bleeding that occur afterwards may influence these behaviours so that the additional effect of the pain caused by amputation does not modify it further.}, issn = {1176-5283}, author = {Stafford KJ and Mellor DJ and Ward RN and Cann B} } @conference {41197, title = {The benefits of sheep recording schemes for genetic research}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {198-202}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Recording schemes designed to provide genetic evaluations at the individual animal level contain basic pedigree and production records fundamental to genetic research. Accessibility, accuracy and consistency of their information and the flexibility of their database design to incorporate new indicator traits with prospects of providing a more accurate or more cost-effective identification of animals able to leave superior progeny influence their value to research. Much research is also likely to benefit from inclusion or access to industry data on animal products and their processing performance beyond the farm gate. Industry-wide evaluations of animals in different flocks can also identify useful contrasting animals for this research as well as for commercial exploitation. Examples of research using industry data from recording schemes are presented to demonstrate these features. They include estimates of non-genetic influences on animal performance, on methods of adjusting for their effects, estimates of phenotypic and genetic parameters, of genetic group and gene effects, of the effects of selection and culling and their impact on selection and crossbreeding strategies. Research embracing new molecular technologies is also discussed. Research of this sort can have high extension impact, especially that geared to early incorporation of results into the animal evaluation procedures of the scheme itself. }, issn = {1176-5283}, author = {Clarke JN and Garrick DJ} } @conference {41200, title = {Cattle behaviour: Comparison of measures of temperament in beef cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {214-217}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {The aim of the study was to evaluate three measures of cattle temperament which incorporate tests of human presence and separation from herdmates. The study utilised 134 heifers and 137 steers which were grazed as two single-sex herds. The cattle were rising 2-year-old, and were of either 3/4 Limousin x 1/4 Jersey or 3/4 Jersey x 1/4 Limousin breed-type. Flight distance was measured for each animal in the paddock and in the handling yards. A test of animal sociability measured the time taken by an animal to move to a pen containing herdmates. Each test was conducted on three occasions at intervals of one month. In contrast to the other two measurements, yard flight distance was highly repeatable with a repeatability coefficient of 0.51 between separate tests for heifers and steers. The repeatabilities for the paddock flight distance and sociability test were 0.36 and 0.34, respectively. In conclusion, the yard flight distance test represented an effective and repeatable measure of cattle response to humans. }, issn = {1176-5283}, author = {Fisher AD and Morris CA and Matthews LR} } @conference {41167, title = {Cloning and characterization of the bovine myostatin promoter}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {90-93}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Myostatin a TGF beta superfamily member has been shown to be present in high levels in the myogenic precursor cells of dermomyotome and in the adult muscle fiber. To identify cis-acting DNA elements involved in myostatin gene expression, we have isolated and sequenced several kilobases of the bovine myostatin promoter region. Sequence analysis of the 1.6 kb immediate upstream region of bovine myostatin revealed several muscle specific transcription factor binding sites such as E-boxes and an MEF2 binding site in this region. }, issn = {1176-5283}, author = {Sharma M and Martin JK and Jeanplong F and Thomas M and Spiller MR and Bass JJ and Kambadur R} } @conference {41212, title = {A comparison New Zealand and overseas Holstein Friesian heifers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {265-269}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {The performance of overseas (OS) and New Zealand (NZ) Holstein Friesian (HF) dairy heifers was compared when fed an all-pasture diet (Grass) or a total mixed ration (TMR) throughout lactation. The four treatments were NZ Grass (n=14); OS Grass (n=9); NZ TMR (n=15); and OS TMR (n=10). Compared with NZ HF, OS HF had a higher live weight and produced more milk, but milksolids yield, efficiency of milksolids production, and persistency of lactation were not different. Compared with HF fed Grass, HF fed TMR produced more milk and milksolids, were more efficient, had a greater persistency of lactation, and ended lactation with a greater body weight. The OS HF genotype was unable to maintain acceptable body condition and live weight on an all-grass diet. This raises serious questions regarding the sustainability and suitability of these genetics for seasonal all-pasture dairying systems. }, issn = {1176-5283}, author = {Kolver ES and Napper AR and Copeman PJA and Muller LD} } @conference {41213, title = {Comparison of selected reproductive characteristics in Overseas and New Zealand Holstein-Friesian cows grazing pasture or fed a total mixed ration}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {270-274}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Lactating overseas and NZ-derived Holstein-Friesian cows were fed either pasture or total mixed ration (NZGrass, n=14; NZ TMR, n=14; OSGrass, n=12; OS TMR, n=13). For cows ovulating before breeding began, mean postpartum anoestrous intervals (PPAI) were 39{\textpm}6, 29{\textpm}4, 27{\textpm}6 and 23{\textpm}2 d, respectively. Of 13 cows with PPAI 43d, four were NZGrass (P<0.02). Of seven with PPAI >43d, four were NZGrass (P<0.05). Growth of the first dominant follicle and corpus luteum through time, and day of emergence of the second follicle wave, measured by transrectal ultrasonography, did not differ between treatment groups. Feeding system affected mean plasma progesterone concentration at emergence of the second follicle wave and number of subordinate follicles recorded during the first follicle wave (4.5 {\textpm} 0.4 and 6.1 {\textpm} 0.5 ng/ml, P<0.02; 6.2 {\textpm} 0.6 and 4.1 {\textpm} 0.7 follicles/d, P<0.05; for grass and TMR, respectively). In summary, both genotype and feed system affected length of PPAI, while feed system influenced aspects of peripheral hormone profiles. }, issn = {1176-5283}, author = {Verkerk GA and Morgan S and Kolver ES} } @conference {41202, title = {Dairy farmer perceptions of the industry{\textquoteright}s {\textquoteright}clean and green{\textquoteright} image}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {222-225}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {The purpose of this research was to quantify how dairy farmers believed their practices contributed to (or harmed) NewZealand{\textquoteright}s {\textquotedblleft}clean and green{\textquotedblright} image. Dairy farmers (n=350) from eight regions of New Zealand were surveyed by mail.The majority of respondents (n=218) were mainly male (88\%), older than 40 years (65\%) and owner-operators (45\%) orsharemilkers (31\%). Some 81\% thought New Zealand dairy farming deserved its {\textquotedblleft}clean and green{\textquotedblright} image, 90\% said thisimproved the marketing of New Zealand dairy products internationally, and 72\% believed consumer perceptions of farmingpractices did affect their purchase decisions. The farming practices most strongly associated with a negative impact on the{\textquotedblleft}clean and green{\textquotedblright} image of dairying were: cows in muddy paddocks (81\% farmers), induction (71\%), bobby calves by theroadside (62\%) and tail docking (59\%). Enhancers of the image were pasture grazing by cows (87\%) and being outdoorsyear round (62\%). The majority of farmers believed larger herds (80\%), bloat drenching (79\%), dehorning (65\%), intensivefertiliser use (65\%), effluent disposal (58\%) and use of antibiotics (53\%) to have no effect on the {\textquotedblleft}clean and green{\textquotedblright} image.Concerns were expressed that a small group of farmers with poor management practice could seriously affect the industry{\textquoteright}s image.}, issn = {1176-5283}, author = {Billones R and Parker WJ and Kuiper D} } @conference {41210, title = {Dairy farming, nitrogen losses and nitrate-sensitive areas}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {256-260}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Dairy farms exhibit large nitrogen (N) fluxes throughout the soil/plant/animal system. These fluxes increase with increasing N inputs and farming intensity, and can lead to significant N losses into the environment. Under New Zealand grazed pastoral systems, the N losses occur predominantly from animal urine. Nitrogen can impact on water quality for human consumption or for aesthetics, recreational use and fisheries via enhanced aquatic plant or algae growth. In this paper, N flows in dairy farms in New Zealand are compared with those in the European Union (EU), where dairy farming is generally more intensive. In the EU, legislation is being used to reduce N losses from intensive dairy farming in nitrate sensitive areas through defined maximum rates of manure application. Progressive reduction in these rates will potentially reduce stocking rates on intensive EU farms such as in the Netherlands, where taxation of farm N surpluses is also used as a deterrent. New Zealand has a lower average farming intensity and lower N losses to the environment than in intensive EU farms. However, farmlet systems research has shown that high N inputs of c. 400 kg N/ha/yr can increase nitrate-N concentration in groundwater by up to twice the recommended maximum for drinking water. In nitrate sensitive areas, such as around Lake Taupo, it is desirable to minimise nitrate leaching and the associated lateral movement to surface water bodies. A range of on-farm options are discussed including limiting external N inputs, increasing N use efficiency via lower protein feed sources, reducing farm dairy effluent N losses, and avoiding direct deposition of excreta to land in autumn/winter using grazing-off or feed-pad systems. Off-farm, there is potential to intercept leached nitrate before it enters surface waters via riparian strips or trenches, or in-stream removal by aquatic plants. In nitrate sensitive areas, there is a need to use a whole catchment approach by examining all contributions to nitrate leaching and not simply targeting one agricultural practice such as dairy farming. }, issn = {1176-5283}, author = {Ledgard SF and de Klein CAM and Crush JR and Thorrold BS} } @conference {41225, title = {Dietary effects on gene expression of lipogenic enzymes in mammary gland of lactating mice}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {311-313}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {The effects of a fat-free or clofibrate-supplemented diet on gene expression of several lipogenic enzymes was investigated in mammary gland and liver of lactating mice. In lactating mammary gland, stearoyl CoA desaturase (SCD) mRNA expression was increased 2.1-fold (P<0.05) by feeding the fat-free diet, whereas clofibrate had no influence compared to control diet. Fatty acid synthase (FAS), acetyl CoA carboxylase (ACC), thioesterase II and lipoprotein lipase (LPL) mRNA levels in lactating mammary gland were unchanged after feeding the fat-free or clofibrate diets compared to control. In livers from lactating mice, the fat-free diet increased expression of SCD 5-fold (P<0.05) and FAS 10-fold (P<0.001) compared to control. ACC expression was unchanged by either the fat-free or clofibrate diet compared to control diet. These data show that, in lactating mammary tissue, expression of key lipogenic enzymes may be manipulated by diet, thus offering a potential means to modify milkfat composition. }, issn = {1176-5283}, author = {Singh K and Harley DG and Grigor MR and McFadden TB} } @conference {41186, title = {Differences in wool characteristics in lines of sheep with high or low levels of backfat thickness}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {159-161}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Relationships between backfat thickness and wool characteristics for lines of Coopworth and Southdown sheep, selected for or against backfat thickness, were studied between years and between different age classes. On average, the lean Coopworth line grew 230 g more greasy wool (P < 0.001), which was 1.7 {\textmu}m finer (P < 0.001) and less variable in diameter (P < 0.05) than the fat line. Other measured wool characteristics were not affected. The Southdown lines did not differ in fibre diameter, variability of diameter or curvature, within age groups. Southdown lambswool was finer (P< 0.001) than hogget or ewe wool (23.6 {\textpm} 4.9, 27.0 {\textpm} 5.6 and 26.7 {\textpm} 5.4). Fibre diameter differences observed in the Coopworth lines may have been a founder effect, as subsequent selection had little impact on it. Selection for leanness increased greasy fleece weight without affecting fibre diameter or staple length. }, issn = {1176-5283}, author = {Merrick NC and Baird DB and McEwan JC and Purchas RW} } @conference {41154, title = {Economic benefit of using a major gene in a nucleus selection programme with limits on inbreeding}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {41-43}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {This study investigates the commercial benefit of including information on an identified major gene in the estimation of breeding values for a breeding nucleus. Two types of selection (dynamic selection to maximise response with controlled inbreeding versus standard truncation selection) and two types of breeding value estimation (using versus ignoring information on a major gene) were compared over 15 generations. Selection strategies based on dynamic rules were commercially superior to strategies using truncation selection under comparable circumstances. Correction of the breeding values of selection candidates for the major gene resulted in extra genotype testing but was commercially superior to ignoring the major gene unless only small numbers of commercial males were sold. Small commercial breeding schemes adopting major gene selection will benefit from the application of selection algorithms that control inbreeding.}, issn = {1176-5283}, author = {Amer PR and Villanueva B} } @conference {41209, title = {The effect of pasture silage quality on milk production and liveweight gain of dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {253-255}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Farmers in NZ have recently been encouraged to increase the quality of pasture silage they harvest. However, there was no New Zealand information available to ascertain the benefits of improved silage quality when it was offered as a supplement to grazing cows. Identical twin sets were divided into three groups in the winter, spring, summer and autumn during the 1998/99 season. Each group was offered a low pasture allowance and in addition, were offered 3 kg (winter) and 5 kg (spring, summer and autumn) DM/cow/day, of High, Medium and Low-quality pasture silage (nominally 10.4, 9.4 and 8.3 MJ ME/kg DM, respectively) as a supplement to pasture. In spring, summer and autumn offering a high quality silage increased milksolids yield from 1.57 to 1.78, 1.09 to 1.28 and 0.63 to 0.89 kg/cow/day, respectively (P<0.05) relative to cows offered Low-quality silage. There were no consistent live weight responses due to pasture silage quality. The spring, summer and autumn measured milksolids response can be calculated as having a net return (at $3.50/kg MS) of 6.7, 5.1 and 8.3 cents per MJME/kg DM increase. }, issn = {1176-5283}, author = {MacDonald KA and Nicholas PK and Kidd JM and Penno JW and Napper AR} } @conference {41185, title = {Effect of sample preparation method on the validity of an early-life predictor of hogget wool bulk in genotypes used to develop GrowBulk sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {155-158}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Selection for wool bulk is normally undertaken in yearlings. In this study, a mixed-sex group of 170 GrowBulk sheep were wool sampled at 6 and 12 months of age. Measurements of fibre curvature and fibre diameter following degreasing a wool sample taken at 6 months of age with either water or solvent, explained 69\% and 67\% respectively of the variation in core bulk at 12 months of age. A combination of fibre curvature and fibre diameter measured following degreasing by either method was equally effective in predicting core bulk at 12 months of age. Precision of the predicted core bulk values was equivalent to direct core bulk measurement. Early-life prediction of core bulk from measurements of fibre curvature and fibre diameter taken close to the skin using consistent sample preparation methods, is a low-cost objective procedure to rank sheep for culling young sheep on wool bulk. }, issn = {1176-5283}, author = {Sumner RMW} } @conference {41221, title = {The effect of supplementation with 3-omega fatty acids on plasma metabolites and ovarian function of dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {297-300}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Two- year- old Holstein Friesian dairy cows (n=20) were allocated to receive either a rumen- protected fish oil supplement (omega group, n=10), starting between 5-6 weeks post-partum, or pasture only (control group, n=10). .Serum metabolites, including cholesterol, urea, glucose and beta-hydroxybutyrate (BOH) were measured weekly from calving through to week 11-12 post-partum. Within 2 weeks of the commencement of treatment, serum cholesterol concentrations had increased significantly in the omega group vs the control group, and continued to increase through to weeks 11-12 post-partum. None of the other serum metabolites measured showed any differences with treatment. However, levels of serum urea, BOH and plasma glucose showed significant variations from week to week . The size of the dominant follicles and corpus luteum were measured, using transrectal ultrasonography, on days 8 to 16 of both oestrous cycles. The corpus luteum of the second cycle was significantly larger in the omega group. The second oestrous cycle was interrupted through an oxytocin challenge carried out to measure prostaglandin synthesis, on day 16 of the cycle. After the oxytocin challenge, the omega group exhibited a longer interval to the next observed oestrus. These results suggest that supplementing dairy cows with 3-omega fatty acids will result in changes at the site of the ovary and uterus.}, issn = {1176-5283}, author = {Meier S} } @conference {41228, title = {Effect on milk characteristics to supplementing cows on a restricted pasture allowance with different amounts of either turnips or sorghum}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {320-323}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {The effect of supplementary feeding 0, 4 or 8 kg DM/cow/d of turnips or sorghum to cows offered a restricted pasture allowance (25 kg DM/cow/d) on milk characteristics (fat, protein and lactose, N fractions, serum proteins, fatty acids (FAP) and solid fat content (SFC)) was investigated. Thirty identical twinsets were used (10 cows/treatment) in a partial cross-over designed experiment comprising two, 10-day periods. Sorghum was higher in fibre (NDF, 65\% v 23\%), total lipid (3.5\% v 1.5\%) and similar for crude protein (9.6\% v 12.0\%) than turnips. Lipid composition differed between crops; turnips had more lauric (C12:0) and less linolenic (C18:3) fatty acids than sorghum. Differences in the chemical composition of the crop were reflected in different milk compositions. Milkfat content was lower for cows fed turnips than sorghum and the effect was greater (P<0.001) with increasing amount of turnips fed (5.5\%, 5.1\% and 5.0\% for 0, 4, and 8 kg DM/cow/d respectively). Milkfat composition also differed for cows fed turnips compared to sorghum. With an increased amount of turnips fed, short, medium and long-chain fatty acids increased (P<0.001) and total unsaturated fatty acids decreased (P<0.001). As a consequence, SFC (an indication of milkfat hardness) also increased. Conjugated linoleic acid (cis-9- trans-11-C18:2) declined (P<0.001) as the level of supplementation with crop increased. The effect was greater (P<0.001) with turnips than sorghum. Compared with the fat components in milk the treatments had minimal effect on milk protein and nitrogen fractions. Feeding cows turnips compared to sorghum decreased (P<0.001) milk urea levels and increased (P<0.001) casein: whey protein ratio. This ratio declined (P<0.05) with increasing rates of supplementation with sorghum. These results show that different feed types can change milk components that influence the efficiency of milk processing, physical characteristics and nutritive value of the final dairy products. }, issn = {1176-5283}, author = {Thomson NA and Clark DA and Waugh CD and van der Poel WC and MacGibbon AKH} } @conference {41150, title = {Effects of an extract from sulla (Hedysarum coronarium) containing condensed tannins on the migration of three sheep gastrointestinal nematodes in vitro}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {21-25}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {The effect an extract of sulla (Hedysarum coronarium) containing condensed tannins (CT) had on the viability of the infective third-stage larvae (L3) of three gastrointestinal nematodes (Haemonchus contortus, Ostertagia circumcincta and Trichostrongylus colubriformis) was tested by the larval migration inhibition (LMI) assay in vitro. The LMI assay measures the ability of test material to immobilize larvae and prevent their migration through 20 mm nylon mesh sieves. The extract from sulla was added to rumen (RF) and abomasal fluid (AF), collected from sheep fed lucerne (Medicago sativa) chaff, to provide concentrations of CT similar to those observed in the rumen and abomasal digesta of sheep fed CT-containing forages (50-1000 mg/ml). Incubation of L3 larvae in rumen and abomasal fluid containing the sulla extract reduced the migration of larvae compared to those in control incubations (no extract added). This study showed that the larvae of T. colubriformis were more resistant (PO. circumcincta (RF 59\%; AF 79\%) and H. contortus (RF 72\%; AF 81\%) were significantly (PT. colubriformis (RF 37\%; AF 26\%). Addition of 2 mg polyethylene glycol (PEG)/mg CT to the incubations partially reduced the effects of the sulla extract on larval migration, particularly in the rumen fluid, suggesting that CT was responsible for most but not all of the inhibitory effect of this extract. }, issn = {1176-5283}, author = {Molan AL and Alexander R and Brookes IM and McNabb WC} } @conference {41224, title = {Effects of chromium picolinate on milk production and plasma insulin concentration in dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {307-310}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Chromium picolinate (CrPic) is a biologically active molecule in which chromium is chelated to an isomer of niacin. It is claimed to reduce plasma cholesterol levels in humans, pigs and hens and to have beneficial effects on muscle and fat composition of humans, pigs and lambs. The metabolic responses recorded in lambs were similar to those observed in cows of high genetic merit for milk production, suggesting that CrPic may increase milk yields by altering aspects of glucose and insulin metabolism. The trial reported in this paper is work investigated the effect of supplementation with CrPic on milk yields and plasma insulin concentration in multiparous Friesian dairy cows grazing pasture. Preliminary measurements of milk yield and composition were made during a pre-treatment period of 1 week in 59 mixed-age dairy cows before separation into four treatment groups balanced for previous milksolids yield, live weight and condition. Beginning at peak lactation, groups received 0, 5, 20, or 100 mg CrPic/day administered once daily by oral drenching. Milk yields were measured and samples taken at weekly intervals for compositional analyses (fat, protein and lactose \%). Blood samples were taken from the jugular at weekly intervals for insulin analysis. Chromium Picolinate had no effect on milk yield or composition. Plasma insulin concentrations did not differ between treatment groups. }, issn = {1176-5283}, author = {Peterson SW} } @conference {41151, title = {Effects of condensed tannins and sesquiterpene lactones extracted from chicory on the viability of deer lungworm larvae}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {26-29}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {The objective of this study was to determine the effects of condensed tannins (CT) and a crude extract containing sesquiterpene lactones (CSL) extracted from chicory (Cichorium intybus) on the viability of the first (L1) and third stage (L3) larvae of deer lungworm, Dictyocaulus viviparus in vitro using the larval migration inhibition (LMI) assay. The CT and CSL immobilised larvae and inhibited their migration through 25 mm nylon mesh sieves. Incubation of L1 larvae in rumen fluid (collected from deer fed pasture) containing 100, 400, and 1000 mg CT/ml, inhibited 12\%, 28\% and 41\% of the larvae from passing through the sieves, respectively while the incubation of L3 larvae with rumen fluid containing the same concentrations inhibited 26\%, 37\% and 67\% of L3 larvae from passing through the sieves, respectively. CT were more effective (P < 0.001) at reducing the viability of lungworm L1 and L3 larvae when added to the rumen fluid (pH 6.6) than when added to the abomasal fluid (pH 3.0). L3 larvae were more sensitive to the action of CT than L1 larvae. Addition of 2 mg polyethylene glycol/mg CT eliminated most of the inhibitory effect of CT against L1 and L3 larvae especially during incubation in rumen fluid. The CSL extract showed similar inhibitory activity in both fluids, indicating that this extract was not affected by the pH of the fluid, and they were more effective against L3 than L1 larvae. }, issn = {1176-5283}, author = {Molan AL and Duncan A and Barry TN and McNabb WC} } @conference {41214, title = {Effects of diet on udder function and regression in Holstein-Friesian Cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {275-276}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {The rate of decline in milk yield after peak lactation is about 10\% per month, for cows in New Zealand grazing pasture diets, and less than 4\% per month in concentrate-fed animals in northern hemisphere environments. Much of the decline in milk yield after peak lactation is associated with a similar proportional loss of secretory cells from the udder and, once lost, these cells cannot be replaced until the dry period before the next lactation. Thus, we have found (unpublished data) that from peak lactation (October) to late-lactation in New Zealand, there was a loss of over 50\% of mammary DNA. Such a loss was also reflected in changes in udder volume (Davis et al., 1985) and also in changes in milk storage capacity in the udder (Davis et al., 1987). Differences in lactational persistency between concentrate and pasture-fed animals suggest that nutrition exerts a long-term effect on milk production through maintenance of mammary secretory cell structures, as well as function. In the present experiment, our hypothesis was that cows fed concentrate diets would maintain milk production better than cows fed pasture over the summer months and that this would be reflected in the functional udder capacity (FUC). FUC is a measure of mammary cell numbers and is highly correlated with milk production (Davis et al., 1987). Further work attempted to correlate changes in FUC with concentrations of blood hormones sensitive to diet. }, issn = {1176-5283}, author = {Davis SR and Farr VC and Auldist MJ and Kolver ES} } @conference {41211, title = {Effects of intensifying catchment land-use on the water quality of Lake Taupo}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {261-264}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Levels of the nitrogen-dependent phytoplankton in Lake Taupo are currently very low, so the clarity of the lakewater is exceptionally good. This is because loads of nitrogen to the lake from the catchment are currently low (averaging 3{\textendash}4 kg N/ha/yr). Changing to more intensive land-uses is likely to increase the nitrogen input. Converting 100{\textendash}250 km2 of sheep/ beef pasture to intensive dairying yielding 30 kg N/ha/yr would increase the overall nitrogen load to the lake by 20{\textendash}60\%. This could cause phytoplankton levels to increase by a similar proportion, so that water clarity would fall by 20{\textendash}40\%.}, issn = {1176-5283}, author = {Vant B and Huser B} } @conference {41159, title = {The effects of shearing Finnish Landrace x Romney ewes in mid-pregnancy on lamb survival, birth and other weights}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {58-60}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {In each of 2 years, 600 Finnish Landrace x Romney ewes were subjected to a range of nutrition levels in early to mid pregnancy. Half the ewes were then shorn at day 70 of pregnancy with a standard comb. In the first year (1997), shearing treatment had no impact on single lamb birth and weaning weights, which were 5 and 29 kg respectively. Treatment improved twin lamb birth weights by 0.2 kg (P< 0.10), and weaning weight 1.4 kg (P<0.10). In the second year (1998), shearing treatment benefited single lamb birth weight (0.2kg; P< 0.10), and weaning weight (1kg; P<0.01) and improved twin lamb birth weight by 0.2 kg (P<0.01). In both years, lambing rate and survival were not affected. Ewe weaning weight, also in both years, was slightly higher in the ewes shorn at day 70 of pregnancy (P< 0.05). }, issn = {1176-5283}, author = {Smeaton DC and Webby RW and Tarbotton IS and Clayton JB} } @conference {41177, title = {Effects of yarding and transport on muscle glycogen concentration in beef cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {124-125}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Low ultimate-pH of beef is desirable because it enhances shelf life, colour and tenderness. Pre-slaughter stress is thought to deplete muscle glycogen and in extreme cases lead to higher ultimate pH of beef. Seventeen-month-old steers were allocated to three treatments (n=15): Control (C, grazing on pasture), Yarded (Y, held for 24 hours in cattle yards) and Yarded plus Transported (YT, as for Y but also trucked for 4 hours during the 24-hour yarding period). The Y and YT animals lost weight (average 25.5 kg) during time off pasture. Plasma glucose and lactate did not differ across treatments. Plasma cortisol and creatine kinase concentrations were increased by YT and plasma non-esterified fatty acids concentration by both Y and YT. Despite these indicators of occurrence of mild stress, especially in YT, muscle (longissimus dorsi) glycogen concentration was not influenced by treatments. Results suggest that increased emphasis on improved animal handling during yarding and trucking of cattle is unlikely to markedly lower the incidence of high-pH beef. }, issn = {1176-5283}, author = {Lambert MG and Knight TW and Cosgrove GP and Death AF and Anderson CB} } @conference {41195, title = {E-Genetics. The role of the internet in genetic improvement}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {192-194}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {This paper reviews trends in the use of the Internet and e-commerce and outlines how this important new technology when coupled with modern Internet accesible databases will provide powerful new decision making tools to breeders andcommercial farmers.}, issn = {1176-5283}, author = {Lindsay P} } @conference {41223, title = {Endocrine control of milk protein production in well-fed dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {303-306}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {A hyperinsulinemic-euglycemic clamp was used to investigate the effect of insulin on milk protein synthesis in wellfed Holstein cows (n=4) with or without additional amino acids. Cows were fed a dry total mixed ration diet formulated to exceed requirements for metabolizable energy and protein. During abomasal water infusion, the insulin clamp increased milk protein yields by 15\% (+128 g/d; P<0.01); when combined with abomasal infusion of casein plus branched-chain amino acids, milk protein yield was increased by 25\% (+213 g/d; P<0.01). Concentrations of casein and whey proteins in milk were increased by insulin clamp treatments, with little change in their relative proportions. Providing amino acids without the insulin clamp had no effect on any production variables. Results confirm the important regulatory role of the endocrine system in milk protein synthesis and demonstrate the potential to produce milk protein is not fully expressed.}, issn = {1176-5283}, author = {Mackle TR and Dwyer DA and Bauman DE} } @conference {41216, title = {Experimental design for detection of quantitative trait loci for Facial Eczema in dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {281-283}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Three hundred and fifty farmers involved in the Livestock Improvement Corporation Sire Proving scheme (SPS) were surveyed, in May 1999, on the incidence of Facial Eczema (FE) in their herds. The SPS farmers were asked to score their 2- and 3-year-old SPS daughters on a five point scale; 1=not affected, 2=slightly affected, 3=severely affected (still alive), 4=culled due to FE and 5=died due to FE, and to comment on any calves or yearlings that were in categories 3 to 5. In the herds with at least one case of FE (50\% of respondees), 89\% of the animals were not affected, 5\% were slighty affected, 5\% severely affected and 1\% were either culled or died primarily from FE. Heritabilities of 3-17\% verified that FE in this dataset was controlled in part genetically and with the DNA bank for all SPS daughters, enables a QTL study to be undertaken. The proposed experimental design is an association study with the pooling of DNA for the 516 daughters that were scored 3 or higher. The control for the experiment would be paternal half sibs for each of the {\textquoteleft}affected{\textquoteright} daughters from the same herd, if possible. To detect linkage disequilibrium (LD) a panel of some 1000 microsatellites would be genotyped.}, issn = {1176-5283}, author = {Spelman RJ and Sellars MD and Sanders K} } @conference {41222, title = {Factors affecting the sex ratio of dairy cattle in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {301-302}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {The sexes of calves born in 1996 (n = 319,539) and 1997 (n = 408,381) to artificial insemination in selected herds were analysed to study the effects of region, dam breed, dam age, semen type, semen breed, semen age, and sires on the sex ratio of calves. There was a significant (P < 0.001) effect of semen type on sex ratio; frozen semen resulted in 1.66\% and 1.24\% more male calves than fresh semen, respectively, in the 1996 and 1997 seasons. There was also significant (P < 0.01) variation among sires in sex ratio, but the heritability estimate for sex ratio was low (h2 = 0.02). No other effects were significant. Industry-wide use of fresh semen will result in more heifer calves from which future replacements can be selected. }, issn = {1176-5283}, author = {Xu ZZ and Johnson DI and Burton LJ} } @conference {41164, title = {Food markets of the future}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {78-82}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Looking from New Zealand at the food markets of the future, presents our industries with something of a challenge. To those with an industry background, this may seem an overcautious view. We are not altogether inexperienced as a food exporter, and can date trading in food products to well before colonisation. Today, over half New Zealand{\textquoteright}s total merchandise exports are food products, and we can count most countries of the world as our markets for food products of some sort or other. So why would meeting these future markets be so challenging? First, our experience as a food exporter has largely been with commodities; only recently has New Zealand started to significantly differentiate and transform its exports into more sophisticated products. Second, the wealthy consumer markets even of today, are hugely more complex than they used to be, and consumers{\textquoteright} purchasing decisions are subject to many new influences, some almost totally unrelated to food, as such. Third, the control our exporters have over their food markets value chains is weak, and while this does not preclude us from participating, our returns are often constrained to f.o.b. margins, which will provide little more than a modest return on the capital we have invested in production systems. Last, some significant barriers to trade remain, in our most important markets. Some would describe these as intractable; suffice to say, progress in dismantling them has been painfully slow. All is not lost however. We are increasingly aware of the demands of future markets and, putting to one side the required action from our trading partners, we know what we need to do to lift our performance. Whether we have the will to change some historical behaviour and adequately re-configure the value chain in New Zealand remains to be seen; however, some radical surgery will be necessary. Of the many factors influencing the future shape of our food markets, technology is surely the most significant. E-commerce, and the dis-intermediation of our value chains that it is causing, is one example. The advances in food technology, biotechnology, and the ways in which we manage production systems are others. We need to understand and harness all these technologies. Market-related factors include rapidly changing lifestyles, the growing strength of food safety and animal welfare interest groups, and the need to be market-ready with consumer friendly, fresh products, all year round. New Zealand will need to do most things differently, and more quickly, to service our future markets with confidence. }, issn = {1176-5283}, author = {Christie R} } @conference {41147, title = {Formulating total mixed rations from forages - defining the digestion kinetics of contrasting species}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {9-14}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {The work described here is the first step in formulating forage-based TMR rations for dairy cows, based on digestion kinetics derived from in vitro and in sacco incubations. Kinetic information has been obtained from 23 contrasting fresh and conserved forages species, including temperate and tropical grass species, legumes (including Lotus spp. containing condensed tannins), herbs, silages, lucerne hay and maize grain. All forages were minced to a particle size similar to chewed material. Estimates of DM solubility (\% DM) and fractional dry matter degradation rates (h-1) determined by in sacco incubations include: white clover (39\%, 0.195), perennial ryegrass (45\%, 0.114), tall fescue (46.8\%, 0.051), paspalum (27\%, 0.068), sulla (51.4\%, 0.121), chicory (41.8\%, 0.260), pasture silage (41\%, 0.083), maize silage (28\%, 0.042). In vitro incubations resulted in five-fold differences between forages in net ammonia release, 2-3 fold differences in volatile fatty acid yield and a three-fold difference in acetate:propionate ratio. The data will be used in simulation models to identify optimal forage mixtures for meeting the nutritional needs of high-producing dairy cows. }, issn = {1176-5283}, author = {Burke JL and Waghorn GC and Brookes IM and Attwood GT and Kolver ES} } @conference {41207, title = {The future for small dairy farms: Constraints, plans and priorities}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {241-246}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Small dairy farms (<60 ha and/or <180 cows) represent about one third of New Zealand{\textquoteright}s dairy herds. Declining real returns for milksolids (MS) and inflation are continuing to squeeze their profitability to the extent that, without change, many are likely to exit the industry in the next decade. A mail survey of 1389 farmers was conducted to quantify their plans for the future, the constraints they faced in improving farm income and ways the dairy industry could assist them. A response rate of 41\% was achieved. The majority of respondents were over 45 years (74.4\%) with the average age being 51 years. Most (85\%) were happy with their farm location, but 48\% said they were dissatisfied with their farm size. However, few would sell to buy a bigger farm elsewhere (17.8\%) or to invest in non-farming activities (24.1\%) Only 24\% expected their children to continue dairying on the home farm. Few believed their own ability, others{\textquoteright} opinions or suitable learning opportunities were limiting their ability to improve farm income. Most believed expenses could be reduced very little (mean = 3.6\%). However, MS production could be increased compared to current levels to a greater extent (mean = 15.8\%, range 0 to 248\%). Factors restricting the improvement of farm income were: the economic and political environment (s=2) (s=median score, where 1=strongly agree and 5=strongly disagree), unfavourable actions of the dairy industry (2), lack of capital (3) and environmental limitations (3). Plans for 2009 included: retired from farming (s=3), (where 1=very unlikely and 5= very likely), on the same farm but no longer dairying (3), no or minor change (2) and have a bigger dairy farm (2). Farmers{\textquoteright} priorities for using a 10\% higher cash surplus were: debt repayment (s=4; as for previous scale), farm development (4), off-farm investment (3) and improvements to the family home (3). While potential exists to increase production on dairy farms with small herds, the survey indicates a considerable reduction in the number of these will occur over the next decade. }, issn = {1176-5283}, author = {Parker WJ and Rauniyar GP and Dooley AE} } @conference {41193, title = {Genetic improvement and importance to sheep and beef farming}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {184-188}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {The agricultural sector has undergone a large change in 15 years from 1985 to 2000. Changes in livestock numbers signpost the changes in agriculture and land use. Over 15 years of restructuring nothing has replaced agriculture{\textquoteright}s contribution to GDP. The agriculture sector change has led to a more efficient sector at all levels and of particular note is the significant increase in sheep productivity. Following from this the potential for further sheep genetic improvement is discussed using the Meat and Wool Economic Service{\textquoteright}s All Classes Sheep and Beef Farm to show farm potential. }, issn = {1176-5283}, author = {Davidson RM} } @conference {41184, title = {Genetic manipulation to modify wool properties}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {147-154}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Over many centuries, genetic selection of sheep for particular meat and wool traits has made steady progress andgiven producers the opportunity to choose from a broad spectrum of well defined breeds. Selection for specific features ofbody frame or fleece has resulted in the emergence of true {\textquotedblleft}meat{\textquotedblright} breeds (e.g. Poll Dorset, Suffolk, Texel) and other breedshighly valued for their fleece characteristics (e.g. Merino, Romney). Whilst such selection tends toward the outer limits ofgenetic variation among sheep, the sheep genome itself and natural mutation rates provide an inbuilt restriction to geneticchange and the appearence of new phenotypic varieties. In comparison, the use of transgenesis to add specific functionalsheep or non-sheep genes to the sheep genome has the potential to greatly expand the phenotypic range possible amongsheep. For example, in a preliminary sheep transgenesis experiment using a cortical type II keratin intermediate filamenttransgene, we have shown it is possible to alter fibre structure and properties. The fact genes from any species may be usedin the transgenesis process provides many experimental options simply not possible using the sheep genome alone. Thispaper is a discussion of some of the recent attempts to modify the genotype / phenotype of wool producing breeds usingtransgenesis. In particular, results of the earliest programmes designed to modify wool fibre properties and fibre growth rates are reviewed.}, issn = {1176-5283}, author = {Bawden CS and Penno NM and McLaughlan CJ and Walker SK and Hynd PI and Rogers GE} } @conference {41198, title = {Genetic parameters for improvement of dual-purpose flock productivity with constraints on mature ewe body weight}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {203-206}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {SIL provides opportunity for inclusion of information on mature ewe body weight in animal evaluations. This paper reports estimates of the parameters needed for these evaluations. Traits analysed were: weaning weight (WWT) and hogget liveweight in May (ALW); hogget yearling liveweight (HLW) and greasy fleece weight (HFW); and pre-mating body weights (ELW), number of lambs born (NLB) and greasy fleece weights of ewes at 2 to 5 years of age. EFW and especially ELW, were highly repeatable (>0.9), the pattern of genetic correlations suggesting that breeding ewes had reached maturity in these traits by 40 months of age. Direct and maternal genetic effects on WWT showed similar heritabilities (0.14{\textpm}0.02 \& 0.18{\textpm}0.02) and were positively correlated (0.20{\textpm}0.08). Maternal influences on traits measured at old ages were much reduced, direct heritabilities being similar to published estimates. WWT showed a high direct genetic correlation with LW8 and HLW (0.82{\textpm}0.02), but lower with ELW (0.70{\textpm}0.06 for 3-year old ewes). LW8 and HLW showed even higher direct genetic correlations with ELW (of the order of 0.90{\textpm}0.02). EFW was highly correlated genetically with HFW (0.80{\textpm}0.03), HLW (0.25{\textpm}0.04), ELW (0.23{\textpm}0.05) and LW8 (0.21{\textpm}0.04). Dual-purpose genetic response predictions were derived using SIL{\textquoteright}s recently revised relative economic values for a dual-purpose index. Its correlation with aggregate breeding value was 0.67. It predicted positive selection responses (per generation and standard deviation of selection pressure) in all traits: LW8 (2.1 kg), EFW (0.14 kg), NLB (0.038 lambs/ewe) and ELW (2.4 kg or 87\% of the predicted single trait response despite the negative economic weight for this trait). Restraining the response in ELW to zero required a ten-fold increase in the negative relative economic value for this trait, and reduced the correlation of the index with aggregate breeding merit to 58\% of its previous value. Such restriction greatly increased the relative contribution of fleece weight to economic response, made little difference to the contribution of NLB (although the absolute rate of progress was nearly halved), and reduced the contribution of growth; maternal effects on weaning weight became relatively more important. }, issn = {1176-5283}, author = {Clarke JN and Dobbie JL and Jones KR and Wrigglesworth AL and Hickey SM} } @conference {41227, title = {Genetics of milk characteristics in New Zealand dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {318-319}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Data collection was integrated with LIC{\textquoteright}s herd testing service using a sample of 102 herds involved in LIC{\textquoteright}s SireProving Scheme (SPS) in 1995. In addition to milk volumefrom herd testing, the concentrations of fat, crude protein(total nitrogen), casein, whey and lactose were determined.The data was collected from over 3,000 cows born in 1996and first calving in the 1998 spring season, these beingpredominantly the daughters of approximately 220 SPSbulls. The milk characteristics were measured at three herdtests on each cow, with each herd having a herd test in eachof the Sept/Oct, Nov/Dec and Jan/Feb periods. Hereafter,we refer to these three periods as stages of lactation.}, issn = {1176-5283}, author = {Johnson DL and Petch SF and Winkelman AM and Bryant M} } @conference {41162, title = {Global opportunities in agricultural trade}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {68-71}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {In the 21st century the central issue of global security and human destiny will be food, land and water. There is already evidence that most conflicts now arise as a result of shortages, misallocation or abuse of these vital keys to human survival and prosperity. Over the coming 50 years the world will add another New Zealand to its population every fortnight. Demand for knowledge about how to produce food and manage landscapes sustainably will be unmatched in human history. But two nations, Australia and New Zealand, are superbly placed to meet such a demand. Many of the answers the world is seeking already exist in our labs and on our farms. The challenge now is for us to build the world{\textquoteright}s leading knowledge export industry that specialises in sustainable food, land and water.}, issn = {1176-5283}, author = {Cribb JHJ} } @conference {41203, title = {Heat challenge of dairy cows in the Waikato: a comparison of spring and summer}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {226-229}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {This experiment was carried out at the Dairying Research Corporation, Hamilton, New Zealand, to evaluate the heat challenge imposed on dairy cows during spring and summer. The diurnal temperature profiles of 18 Friesian cows were recorded over five days in November and five days in January. Temperature-humidity index and black globe temperature were used to assess the potential of the environment to induce heat stress. Cows in January had higher maximum (39.5 versus 38.9 {\textpm} 0.09 {\textdegree}C), minimum (37.9 versus 37.6 {\textpm} 0.09 {\textdegree}C) and mean (38.6 versus 38.4 {\textpm} 0.05 {\textdegree}C) daily body temperatures than in November, corresponding with higher ambient temperatures and solar radiation in January. Temperature-humidity indices were highest in January between 09:30 h in the morning and 19:30 h at night and within the range reported to cause mild heat stress in dairy cows (72 to 78). Respiration rate (47 versus 37 {\textpm} 1.4 breaths/minute) and water intake (51 versus 18 {\textpm} 2.3 l/cow/day) were both higher in January than in November. }, issn = {1176-5283}, author = {Bluett SJ and Fisher AD and Waugh CD} } @conference {41158, title = {Herbage quality and growth rate of single and twin lambs at foot}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {55-57}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Single and twin lamb growth rates, herbage mass and quality were monitored 3-5 times from birth to weaning on 6 farms in the southern North Island. Lambs (n = 50-80/farm) were tagged and weighed at birth, and ewes (n = 20-50/farm) grazing with the monitored lambs were tagged and weighed from docking. The average live weight gain (LWG) from birth to weaning was 273 g/d (229-311) and 220 g/d (152-279) for single and twin lambs respectively (P<0.001) and remained relatively static over the lactation period. Mean herbage energy concentration averaged 10.5 MJME/kg DM during the first two months of lactation but had declined to 8.9 by weaning (P<0.001). In conclusion, twin lamb growth rates on hill country are considerably lower than those of single lambs. }, issn = {1176-5283}, author = {Litherland AJ and Lambert MG} } @conference {41206, title = {The human factor: Influence on livestock performance and welfare}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {237-240}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Research in the livestock industries in which animals have frequent contact with humans has shown that human-animal interactions can limit the productivity and welfare of these farm animals. Many of these interactions are routinely and, at times, habitually used by stock-people. While these interactions may appear harmless to the animals, this research has shown that the frequent use of some of these routine behaviours by stock-people can result in farm animals becoming highly fearful of humans. It is these high fear levels, through stress, that appear to limit animal productivity and welfare. This research has also shown that one of the antecedents of stock-person behaviour is the attitude of the stock-person towards interacting with his or her farm animals. Intervention studies in the dairy and pig industries have shown the potential of cognitive-behavioural intervention techniques designed to specifically target those attitudes and behaviours of stock-people that affect animal fear and, in turn, animal productivity. }, issn = {1176-5283}, author = {Hemsworth PH} } @conference {41189, title = {The impact of liveweight and liveweight change on wool staple tenacity in Romney hoggets}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {171-173}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Three lines of Romney sheep were selectively bred over 10 years for high or low staple tenacity, or were bred at random. Each crop of ewe and ram hoggets was weighed at strategic intervals throughout the year and staple tenacity was measured on mid side wool harvested in spring. Relationships of staple tenacity with live weight and liveweight change were examined by single and multiple regression analysis of data from a total of 2696 hoggets. The biggest single influence on staple tenacity in the ram hoggets was selection line, which accounted for 23.3 \% (P2, but only 50 \% of those with gains less than 20 g/day achieved that milestone. For the ram hoggets, the corresponding values were 66 \% and 38 \%. These findings provide a basis for liveweight targets to achieve chosen levels of staple tenacity in Romney hoggets. }, issn = {1176-5283}, author = {Smith MC and Bray AR and Baird DB} } @conference {41155, title = {Incidence of bearings in ewes that had a bearing the preceding lambing}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {44-46}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {In the summer of 1998/9, 220 mixed-age breeding ewes were obtained from eight North Island farms. Half of these ewes had had a bearing in 1998 (PB ewes) and the other half were flock mates that had not (NB ewes). Ewes were fed in excess of their requirements from eight weeks before lambing and ewe condition had increased by 0.4 CS units by lambing. At scanning 15\% of PB ewes were dry compared to 10\% of the NB ewes. Pregnant PB and NB ewes also had similar scanning percentages (151\% vs 142\% respectively). Twenty percent of PB ewes had a bearing in 1999 (17\% in single and 29\% in twin pregnant ewes) compared with 0\% in NB ewes (P<0.001). Pre-lambing bearings occurred 18 {\textpm}2 days (2-33 days) before lambing. There was a 5\% bearing incidence after lambing. Eleven percent of the ewes treated for bearings died before lambing and 78\% of surviving treated ewes produced a live lamb. In conclusion, high feeding levels in late pregnancy do not necessarily cause bearings. Ewes with bearings should be clearly identified and culled as they are more likely to have bearings the following year.}, issn = {1176-5283}, author = {Litherland AJ and Lambert MG and Knight TW and Cook T and McDougal DB} } @conference {41161, title = {Increased ovarian response following pre-synchrony of superovulated red deer (Cervus elaphus) hinds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {65-67}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {The effects of two modified superovulation protocols on ovarian response in red deer were compared to a standard protocol. Twenty mixed-age red deer hinds were allocated to one of three treatment groups during the breeding season: Group S (n=7) received our standard superovulation protocol of 12-days treatment with an intravaginal progesterone-releasing device (CIDR{\textquoteleft}, InterAg, NZ), eight injections of 0.45 mg ovine FSH (Ovagen, Immuno-Chemical Products Ltd., NZ) 12 h apart, beginning 72 h before CIDR removal with 200 iu eCG (Folligon, Intervet, Australia) added with the last injection. Group M1 (n=7) hinds received the same CIDR and eCG treatment, but Ovagen was delivered as four daily injections of 0.9 mg Ovagen dissolved in 30\% polyvinylpyrrolidone (PVP-40; Sigma Chemical Co, USA). Group M2 (n=6) hinds were pre-synchronised using a 12-day CIDR{\textquoteleft} treatment and then received seven daily injections of 0.9 mg Ovagen dissolved in 30\% PVP beginning four days after CIDR removal. A prostaglandin analogue (2 ml Estrumate, Pitman-Moore NZ Ltd, NZ) was administered concurrent with the sixth Ovagen injection. Ovarian response was highest in M2 hinds. Mean ovulation rates ({\textpm}S.E.M.) were 4.9 {\textpm} 0.83, 3.4 {\textpm} 0.70 and 8.7 {\textpm} 1.20 for S, M1 and M2 respectively (P>0.05). Two S and three M1 hinds were anovulatory following superovulation treatment, but all M2 hinds ovulated (P>0.05). Pre-synchrony of red deer hinds before daily injection of Ovagen is an effective superovulation protocol. However, further work is required to ascertain if viable embryos are produced following the extended period of FSH exposure. }, issn = {1176-5283}, author = {Scott IC and Asher GW and O{\textquoteright}Neill KT and Littlejohn RP} } @conference {41169, title = {Involvement of calpains in postmortem tenderisation: A review of recent research}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {99-102}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Tenderness is an important determinant of meat quality. Inconsistency and variability in tenderness have been identified as major problems for the meat industry (Morgan et al., 1991). It is well documented that tenderness improves during postmortem storage of meat but the mechanisms involved remain controversial. The general consensus is that proteolysis of structural muscle proteins causes tenderisation but alternative theories suggest that changes in the actin-myosin interaction (Goll et al., 1997) or a non-enzymatic effect of calcium on muscle proteins (Takahasi, 1999) or a rise in ionic strength (Ouali, 1990) may be involved. However, discussion of these theories is not within the scope of this review. With regard to postmortem proteolysis, the calpain system is thought to play a major role. Calpains are calcium-activated proteases with an optimum activity at neutral pH. In skeletal muscle, the calpain system consists three proteases, m-calpain, m-calpain and skeletal muscle-specific calpain, p94, and an inhibitor of m- and m-calpain, calpastatin. The involvement of calpains in postmortem tenderisation has been the subject of several reviews (Goll et al., 1991; Koohmaraie, 1988, 1992a, 1994, 1996; Ouali, 1990). Since these reviews, new information has become available which has provided answers to some of the questions on the role of calpains in postmortem tenderisation. The purpose of this review is to discuss some of these issues in the context of recent results. For further information on postmortem proteolysis and meat tenderness, or characteristics of the calpain system, the reader is referred to a number of excellent reviews (Penny, 1980; Greaser, 1986; Croall and DeMartino, 1991; Ouali, 1992; Sorimachi et al., 1994; Ono et al., 1998). }, issn = {1176-5283}, author = {Geesink GH and Ilian MA and Morton JD and Bickerstaffe R} } @conference {41156, title = {Lamb and ewe performance of East Friesian x Coopworths relative to pure-bred Coopworths}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {47-50}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Purebred East Friesians (EF) sires were used in both the 1996 and 1998 matings (n=2 and 4, respectively) to generate 62 and 66 progeny for the two years. These animals were compared with approximately 1000 COOP lambs in each year for growth, ultrasonic fat and muscle depths, wool, dagginess, host resistance to internal parasites, and reproductive performance. For the 1998 mating, one F1 sire and 24 F1 dams were mated to COOP ewes and rams respectively to produce approximately 73 paternal and 33 maternal backcross progeny. Twenty four EF cross ewes were mated in each of the 1998 and 1999 birth years, and reproductive performance recorded. On average, the EF cross progeny had a live weight advantage (P0.05) after adjustment for live weight, but EF cross progeny had significantly lower C and GR measurements. EF cross progeny had lower fleece weight at 12 months (-0.46kg; P<0.001) than COOP. Average dag score differed between sire breeds with EF cross having lower scores (0.4 verses 1.2) compared to COOP. Sire breed differences in resistance to parasites were not significant. Analysis of the limited EF backcross data indicated positive EF direct and maternal effects for weaning weight, negative EF direct effects for dag scores, and negative EF direct and maternal effects for fleece weight. EF cross ewes performed significantly better (P<0.001) in lambs born per ewe lambing than the purebred COOP for both 2-tooth (2.57 cf. 1.84) and mixed-age (2.76 cf. 1.98) classes. The high lambing percentage in EF cross ewes meant that more than 70\% of mixed-age ewes had three or more lambs per lambing, which could result in management difficulties. There was significant overlap in the sire-breed ranges for all traits, meaning selection of sire was more important than breed selection. }, issn = {1176-5283}, author = {Jopson NB and Dodds KG and Knowler KJ and Wheeler R and McEwan JC} } @conference {41160, title = {Lamb survival traits in Coopworth sheep selected for high or low backfat depth}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {61-64}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Consumer preferences for lean healthy meat have driven genetic selection for leanness in the terminal sire and dual purpose sheep industries over the last 20 years. The Invermay Coopworth lean and fat selection lines were established in 1980 to study the effects of selection for live weight adjusted leanness on carcass traits, and the correlated responses in other traits. This paper reports the findings of two year{\textquoteright}s data on lamb survival and performance in the lean and fat selection lines. Records were collected from 817 lambs comprising 325, 337 and 155 from the fat, lean, and a random-bred control line, respectively. Neo-natal mortality was not significantly different between the three lines, with approximately 93\% of lambs born surviving until tagging. Lamb survival from tagging until weaning differed significantly between the selection lines (P<0.05), with fat line animals having 10.9\% better lamb survival than lean line animals (95.5 verses 84.6\%), after adjusting for differences in year, birth weight, birth rank, skin thickness, wool length, age of dam, mothering ability and ewe udder volume. Fat line lambs were 0.9 {\textpm} 0.1kg (mean {\textpm} SEM) lighter than lean line animals, with control line animals intermediate. Udder volume (as measured by water displacement) did not differ between the three lines. Mothering ability (as measured by distance from ewe to the new born lamb during handling in the field) did not differ significantly between the lean and fat lines. Fat line lambs had thicker skins than lean line lambs at the same birth weight (P<0.01), but had no difference in wool length. The differences in lamb mortality between the lean and fat lines cannot be fully explained by differences in birth weight, indicating some physiological difference between the lines affecting survival. }, issn = {1176-5283}, author = {Jopson NB and Greer GJ and Bain WE and Findlay JA and McEwan JC} } @conference {41170, title = {Live animal contribution to beef tenderness}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {103-106}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Defining a production and processing system for beef that ensures a consistent and high quality eating experience remains a major challenge to the industry. While significant progress has been made in developing effective processing specifications to enhance quality and consistency, the control and manipulation of animal variability is not as well understood. By avoiding detrimental processing and ensuring a normal ultimate pH (>5.6), an analysis of the M. longissimus dorsi from 265 cattle failed to identify any significant toughness (<10kgf shear force) when the meat is allowed to reach final tenderness during conditioning. However, both the initial (at rigor) shear forces and rates of tenderisation were highly variable, and toughness can be attributed to insufficient ageing. Low initial shear forces were only partially explained by the structural properties of the raw muscle, and probably need to be understood in terms of the textural changes that occur during heating. }, issn = {1176-5283}, author = {Daly CC} } @conference {41199, title = {Livestock Improvement Corporation Lecture: Sustaining fitness and welfare in the dairy cow}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {207-213}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {The {\textquoteleft}Animal Welfare Problem{\textquoteright} is, in fact, two problems. One is the problem as perceived by the general (human) public. This tends to classify words like natural and grass as {\textquoteleft}good{\textquoteright}; words like intensive and high output as {\textquoteleft}bad{\textquoteright}. According to this simplistic world view, the New Zealand Dairy Industry ranks as good; an image which is your advertising industry reinforces by happy pictures of Jersey cows grazing peacefully, sometimes, quite shamelessly, with calves at foot! The other, quite distinct animal welfare problem is that perceived by the cows themselves, which cannot be reduced to pretty pictures. My address will consider only this latter problem; the impact of modern feeding, breeding and management practices on the welfare of the dairy cow herself. It is for you to decide how this information may be used for the good of the dairy cow and the good of the dairy industry. }, issn = {1176-5283}, author = {Webster AJF} } @conference {41157, title = {Liveweight gain of young sheep grazing tall fescue or perennial ryegrass swards of different white clover content}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {51-54}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {It is not clear whether the inherent qualities of tall fescue or the legumes grown with it are responsible for the wide range of liveweight gains in young sheep grazing these swards. The objective of this experiment was to determine the value of the white clover content in tall fescue swards relative to perennial ryegrass/white clover swards in respect to live weight gain in young sheep. Nine trials (ranging from 41 to 190 days) were conducted at AgResearch Poukawa and AgResearch Lincoln from spring 1995 to autumn 1997 using 15 animals as replicates in 19 treatments. Overall, live weight gains ranged from {\textendash}87 to 366 g/head/day. Even small increases in clover content had large positive effects on liveweight gain of young sheep grazing both perennial ryegrass and tall fescue. At the same pasture mass and composition, all spring grazing liveweight gains were significantly greater than those in autumn (P<0.001). Tall fescue swards appear to sometimes produce higher liveweight gains than perennial ryegrass-based swards, but this is by virtue of growing more white clover, particularly in spring.}, issn = {1176-5283}, author = {Hyslop MG and Fraser TJ and Smith DR and Knight TL and Slay MWA and Moffat CA} } @conference {41171, title = {Manipulating processing to generate meat quality attributes appropriate for diverse markets}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {107-109}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {The optimal processing conditions for different meat quality attributes can often be conflicting. For example, conditions that maximise the rate of tenderisation may be responsible for increased drip and cooking loss, a reduction in colour stability and changes in textural characteristics. The conditions for optimal processing can therefore be defined as those conditions that establish the best compromise between conflicting meat quality requirements for different end-uses or markets. Methods of defining processing specifications tailored to defined endpoints are considered, specifically through the control of the rate of rigor mortis onset using combinations of electrical inputs and chilling regime. }, issn = {1176-5283}, author = {Simmons NJ and Daly CC and Gilbert KV} } @conference {41165, title = {A multifaceted approach to providing consumers consistent meat tenderness}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {83-84}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {A comprehensive program of research on the physiological and genetic basis of variation in meat tenderness has beenundertaken. Key processes of tenderization have been identified; intervention and testing protocols have been devised andevaluated, including calcium chloride injection and in-line tenderness testing/classification. Genetic loci influencing meattenderness have been detected, and DNA markers developed to aid selection and eventual identification of the allelicvariation underlying these effects. This combined effort is leading to management and production approaches to providinga consistent, tender meat product.}, issn = {1176-5283}, author = {Smith TPL and Wheeler TL and Shackelford SD and Stone RT and Casas E and Bennett GL and Keele JW and Koohmaraie M} } @conference {41180, title = {Muscle glycogen and blood parameters in genetic strains of Angus cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {132-134}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Angus selection and control herds in two long-term breeding studies were compared for muscle glycogen and blood parameters pre-slaughter. Trial 1 involved 3 years of bulls (n=85) from a yearling-weight (W) selection herd and a control (C1) herd, differing by 19\% in yearling weight. Trial 2 involved one year of steers (n=45) from an experiment to increase age at puberty (A+ herd) or to reduce age at puberty (A- herd), relative to a control (C2) herd, with age at puberty differing from the C2 mean by 11\% (A+) and -10\% (A-). In Trial 1, muscle biopsies were taken for glycogen assay (Years 1 and 2), and blood samples were taken (Years 1-3) for creatine kinase, cortisol, lactate, non-esterified fatty acids (NEFA) and glucose; animals in Trial 2 (Year 2 only) were sampled at the same time as Trial 1. Samples were taken at 17 months of age (Year 1), 10 and 19 months (Year 2), and 19 and 20 months (Year 3, with an extra blood trait added). Muscle glycogen concentration was 19\% higher in the W than C1 herd (P<0.05), and it was significantly lower in the A+ herd than in the other two herds (P<0.001). Cortisol (P<0.05) and glucose concentrations (P<0.01) were lower in the W than the C1 herd; NEFA was higher in the C2 herd than in the A- or A+ herds (P<0.05). No other blood parameters differed between herds. Repeatabilities for the 5 main blood traits in Trial 1 ranged from 0.14 to 0.38, being highest for creatine kinase (if excluding outliers), but repeatabilities were all low in Trial 2 (highest value only 0.13). The main conclusions came from Trial 1, in which most data had been collected, namely that across-year differences were found for 3 traits between herds (muscle glycogen, cortisol and glucose). }, issn = {1176-5283}, author = {Morris CA and Lambert MG and Knight TW and Fisher AD} } @conference {41166, title = {Myostatin, a negative regulator of muscle growth, functions by inhibiting myoblast proliferation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {85-89}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Myostatin, a member of the transforming growth factor-b (TGF-b) superfamily has been shown to be a negative regulator of myogenesis. However, the molecular mechanism of myostatin function is, so far, not understood. Here we show that myostatin is synthesised and proteolytically processed in myoblasts and that myostatin functions by controlling the proliferation of muscle precursor cells. When actively growing C2C12 myoblasts were incubated with myostatin, the proliferation of myoblasts decreased with increasing levels of myostatin. Furthermore, we show that the myoblast inhibition by myostatin is reversible, such that, myoblasts retain the ability to proliferate after myostatin protein is removed. FACS analysis revealed that myostatin inhibited myoblast proliferation through preventing the progression of myoblasts from the G1 to S-phase of the cell cycle. Thus, we propose that the generalised muscular hyperplasia phenotype observed in animals that lack functional myostatin could be as a result of deregulated myoblast proliferation. }, issn = {1176-5283}, author = {Thomas M and Langly B and Berry C and Sharma M and Kirk S and Bass J and Kambadur R} } @conference {41163, title = {New Zealand{\textquoteright}s food exports in the 21st century: whither the green option?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {72-77}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Over the last 8 years, several major horticultural industries have engaged in a process of {\textquoteleft}greening{\textquoteright} their food exports. This has been achieved through the fostering of organic and/or Integrated Pest Management (IPM) systems. Our analysis indicates that the most successful greening strategy has taken a two-tier approach {\textendash} with a peak organic product, and a more mainstream product using IPM to create residue free fruit. The two-tier approach can be demonstrated to have advantages over an exclusive focus on either greening option. These industry developments have emerged partly in response to new niche markets for green and healthy foods. These markets are increasingly influenced by two emerging trends. First, is the emergence of {\textquoteleft}green protectionism{\textquoteright} as a political strategy in the EU and Japan. By switching from price support to environmental support payments, and raising barriers to food imports on the grounds of food safety and environmental concern, governments can achieve the politically advantageous outcome of serving the interests of both domestic rural producers seeking protection from cheap food imports, and urban middle class consumers concerned about food safety and the environment. The second emerging trend is the intensification of {\textquoteleft}food scares{\textquoteright} during the 1990s. Social scientific analysis would suggest that certain features of a food scare {\textquoteleft}lock in{\textquoteright} a scare for a prolonged period of time. Currently, scares involving BSE and GM foods are locked in and must be accounted for in strategy export decisions. Evidence from successful horticultural export strategies suggests that a wider range of food export industries should be contemplating a two-tier greening strategy to survive these emerging trends in the global market.}, issn = {1176-5283}, author = {Campbell H and Fitzgerald R} } @conference {41220, title = {Patterns of luteinising hormone release and embryo recovery following superovulation of cycling and anoestrous lactating dairy cows and in non-lactating cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {295-296}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Lactating dairy cows, either during postpartum anoestrus (LA; n=10) or returned to oestrous cyclicity (LC; n=10), and cycling non-lactating dairy cows (DC; n=10) were superovulated with follicle-stimulating hormone during a progesterone supplementation treatment, inseminated and embryos recovered non-surgically 7 days later. Blood samples were obtained during the period of oestrus to determine plasma concentrations of luteinising hormone (LH). Number of corpora lutea varied (14.6{\textpm}1.6, 8.1{\textpm}1.5, and 8.7{\textpm}1.9 for LC, LA and DC cows, respectively; P<0.02), but not the total number of all ova and embryos, or the total number of transferable embryos per cow. There were no significant differences between groups in either mean time from start of sampling to peak LH (37.0{\textpm}3.9, 34.5{\textpm}3.6 and 36.2{\textpm}4.5 hours for LC, LA and DC cows, respectively) or mean LH peak (12.5{\textpm}3.6, 16.6{\textpm}3.3 and 13.4{\textpm}4.2 ng/ml for LC, LA and DC cows, respectively).}, issn = {1176-5283}, author = {Verkerk GA and Taufa VK and Hooper R} } @conference {41208, title = {Performance by dairy cows grazing two perennial ryegrass cultivars}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {247-252}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {The effects of two high-endophyte perennial ryegrass cultivars ({\textquoteleft}Aries HD{\textquoteright} or {\textquoteleft}Yatsyn 1{\textquoteright}) on the performance of lactating dairy cows were investigated during a two-year trial. Spring calved cows (Year 1, n = 359; Year 2, n = 570) were allocated to one of two herds. Herds grazed the cultivars as part of each grazing rotation from November to May for the 1997/98 and 1998/99 seasons. Milksolids production was higher (P<0.001) from the Aries HD herd compared with the Yatsyn 1 herd (228 vs. 202 kg MS/herd/day, Year 1; 340 vs. 294 kg MS/herd/day, Year 2, Aries HD and Yatsyn 1 herds, respectively) (P < 0.001). Milk fat \% and protein \% did not differ significantly (P>0.1) between herds. Significantly (P<0.001) more body condition (+0.8 of one body condition score) and more live weight (+17 kg) was gained by cows grazing Aries HD during Year 2. Interval from start of mating to predicted conception tended to be longer for cows grazing Yatsyn 1 (+ 6 days) during Year 1 (P = 0.06). Significantly different cow performance from ryegrass cultivars that produce similar yields of dry matter may be due partly to differences in forage quality and endophyte toxins. Aries HD tended to be more digestible than Yatsyn 1 and was associated with lower concentrations of ergovaline, an alkaloid produced by Neotyphodium endophytes that has been associated previously with reduced animal performance.}, issn = {1176-5283}, author = {Westwood CT and Norriss MG} } @conference {41145, title = {Perspectives and role of Animal Production/Science in the New Millennium}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {1-4}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Last year, as my first function as president of NZSAP, I was privileged to attend the AAAP meeting held in conjunction with the 8th World Congress on Animal Production in Seoul Korea. The theme of this congress was {\textquotedblleft}Sustainability of animal production in the 21st century and the quality of human life{\textquotedblright}. Information presented showed that the world population will increase to and plateau at 9.5-10 billion by the year 2050, an increase of 60-70\% over the present population. I had known that the world population is experiencing a period of exponential growth but I had not fully comprehended the impact and immediacy of the problem. I, like so many others, have largely ignored such information as being too far away in both time and location to be of great concern. However, in 6 months time we enter the new millennium and 2050 does not now seem so far off. Whether we like it or not, we cannot remain blissfully ignorant of the world situation. Modern technologies ensure within hours we know about any major event that happens in any part of the world.}, issn = {1176-5283}, author = {Elvidge DG} } @conference {41219, title = {The pharmaceutical scientists{\textquoteright} role in animal production: An historical and future look at the evolving area of controlled drug delivery in animal production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {291-294}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {In the field of controlled-release veterinary drug delivery, the utilization of new routes of administration or the development of new delivery systems are of considerable interest. Indeed, because of the large number of production animals and the problems associated with the administration of drugs to these animals, the potential for utilizing novel routes of administration or for developing controlled release products are enormous. However, such a potential will only be fully realized if safe, practical and effective delivery systems are rationally designed and tailored to the end users needs through collaborative efforts between animal, veterinary and pharmaceutical scientists. The intent of this presentation is to summarize the state of the art of controlled release systems in the veterinary field. It also intends to provide an overview of recent developments in this area and to look toward the future to examine the directions in which veterinary pharmaceutics is heading. Examples of currently available and future veterinary controlled release drug delivery systems will be given and explained throughout the presentation including ruminal boluses, intravaginal devices, externally applied drug delivery systems, injectable and implantable systems.}, issn = {1176-5283}, author = {Rathbone MJ} } @conference {41174, title = {Pre- and post-rigor treatment of intermediate pH beef to reduce toughness}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {115-116}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {As injections of acid and calcium chloride solution reduce toughness in beef of normal pH (5.4 - 5.7) beef, these solutions may also tenderise intermediate pH (5.7 - 6.2) beef. Portions of intermediate-pH striploins from four bulls were allocated to the following treatments :- control, lactic acid (0.55 M, 10 \% w/w, injected within two hours of slaughter) or calcium chloride (0.3 M, 10 \% w/w, injected 20 hours after slaughter). The samples were stored at 15{\textdegree}C for 24 hours, then at - 1{\textdegree}C for a further nine days. 24 hours after slaughter the shear force of the lactic-acid-treated samples was nonsignificantly less than the control (12.7 vs 15.4 kgF). Nine days after slaughter, the lactic acid and control samples remained unacceptably tough, while the calcium chloride samples (7.5 kgF) were acceptable. Therefore, it may be possible to use calcium chloride to reduce intermediate pH toughness. }, issn = {1176-5283}, author = {Thomson BC and Auld MM and Simmons NJ} } @conference {41178, title = {Prediction of DEVCo cut weights from chilled ovine carcasses using single-frequency bioelectrical impedance measurements}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {126-128}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Single-frequency bioelectrical impedance (resistance and reactance) was measured from one hundred and thirteen chilled lamb carcasses. The carcasses were later cut into the DEVCo cuts and every cut was weighed. These cuts were: Legs, Loin, Rack, Shoulders, Shanks, Flap, Breast and Neck. The bioelectrical impedance data, together with carcass weight and temperature, were used to predict the weights of each of the DEVCo cuts. The best prediction was for the DEVCo Legs cut (adjR2 = 0.945), and the worst prediction was for the DEVCo Neck cut (adjR2 = 0.369). The data analysis revealed carcass weight to be the single best predictor of DEVCo cut weights, and that adding the bioelectrical impedance data did not improve prediction significantly. }, issn = {1176-5283}, author = {Jelenak A and Marchello MJ and Clarke RD} } @conference {41148, title = {Prediction of post-partum anovulatory interval in dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {15-18}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Changes in a range of metabolites and body condition parameters in lactating cows were measured during early lactation to determine if any key indicators or combination of key indicators could be used as a predictor of length of post-partum anovulatory interval (PPAI). Fifty-three cows in a range of body condition scores were involved in the trial which ran from calving to 10 weeks post-calving. Plasma non-esterified fatty acids (NEFA) and serum cholesterol, glucose, betahyroxybutyrate (BOH) and urea content were measured in weekly samples. Live weight and body condition score (BCS) were measured weekly.Cows were categorised into four groups. Three groups were based on the post-partum anovulatory interval (PPAI). PPAI was defined as the interval between calving and the first evidence of oestrus behaviour. The fourth group contained all the two-year-old cows only. There was a calving interval of 31 days from the first to the last cow to calve. The nadir for live weight for all groups occurred one week after calving. Animals with a shorter PPAI had higher live weights on all occasions, with live weight at week 5 having the strongest association with length of PPAI (P<0.001). Mean BCS was higher for animals with a PPAI<60 days. Plasma urea concentrations were associated with PPAI at weeks 3 and 4 (P<0.01). NEFA and glucose were correlated with PPAI at weeks 3 and 4 only, respectively. There was no association between cholesterol or BOH with PPAI. These results demonstrate that the selected variables do not contribute greatly to prediction of PPAI. Those measures which give the closest association with PPAI are live weight, BCS and age. }, issn = {1176-5283}, author = {Clark BA and Chagas LM and Gore PM and Dow B and Verkerk GA} } @conference {41173, title = {Preliminary beef carcass composition data from breed-crosses in a genetic marker trial}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {113-114}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {A collaborative project has been established in AgResearch and at the University of Adelaide to identify genetic markersfor carcass composition and meat quality traits in beef cattle. Two extreme breeds were used, Jersey (J) and Limousin (L).First-cross Jersey x Limousin bulls (X) were mated to cows of both breeds to produce three-quarter Jersey (XJ) and threequarter Limousin (XL) animals. A total of 261 and 155 back-cross cattle of both sexes were slaughtered as 2-year-olds atRuakura in the springs of 1998 and 1999, respectively. A further 400 cattle of the same back-crosses are under evaluationin Australia. Relative to the mean off-pasture weight and hot carcass weight of the XJ cattle slaughtered at Ruakura in1998 (404 and 202 kg), the corresponding XL means were 472 and 262 kg respectively, 1.8 and 2.6 phenotypic standarddeviations (s.d.) heavier. A series of carcass composition traits was obtained from the weights of saleable meat, trimmedfat and bone from individual joints on the right side of each animal, after 24 h in the chiller. Over all joints, the weights ofmeat, fat and bone (as a \% of their total) were 66.6, 9.6 and 23.8 for XJ and 71.7, 7.1 and 21.2 for XL, representingdifferences of 2.8, 1.4 and 2.2 s.d. units respectively. Weights of high value cuts (\% of side weight) were 50.4 for XJ and52.7 for XL, a 2.3 s.d. difference. Ratios of meat to bone were 2.80 for XJ and 3.93 for XL, a 5.5 s.d. difference. Standarderrors of all the above differences in s.d. units were 0.16. The largest differences between the two breed crosses for theabove traits were 2.8 and 5.5 s.d, for meat percent in the side, and for meat to bone ratio, providing good opportunities forgenetic marker studies. In the AgResearch animals, consisting of progeny from three sire groups, markers from over halfof the genome have been analysed so far. A significant marker has been identified for meat percent in the side. The twoinformative sires had the same genotype for this marker, and the difference between sire-derived alleles in their effect onmeat percent averaged 0.99 s.d. (F statistic for each sire, 45.47 and 8.84).}, issn = {1176-5283}, author = {Morris CA and Cullen NG and Bottema CDK and Crawford AM and Hyndman DL and Pitchford WS} } @conference {41146, title = {Preparation of fresh forages for incubation and prediction of nutritive value}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {5-8}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {In vitro and in sacco digestion offers a rapid and inexpensive method for evaluating nutritive value of ruminant feedstuffs. This study compared the conventional freeze dried and ground (FD) preparation with chopping to 6-mm lengths (C) and mincing (M) to represent chewed forage. In sacco and in vitro comparisons were made with perennial ryegrass (RG), white clover (WC) and Lotus corniculatus (LC). The mean proportions of large (>1.0mm) and soluble dry matter (DM) for the three forages were: M, 0.38 and 0.44; C, 0.76 and 0.21; FD, 0.35 and 0.34 respectively. Disappearance of DM and crude protein (CP) during the first 12 hours of rumen incubation was substantially lower for chopped forages. Minimal lag times before the onset of protein degradation were observed following mincing. Yields of ammonia from proteolysis in in vitro incubations were lowest for C and usually highest for M preparations. Preparation also affected yield but not proportions of VFA. These data show that ranking of forages for digestibility is affected by preparation and mincing appears to be a more suitable preparation for assays than chopping and freeze drying and grinding. }, issn = {1176-5283}, author = {Barrell LG and Burke JL and Waghorn GC and Attwood GT and Brookes IM} } @conference {41218, title = {Prevalence and incidence of subclinical mastitis in dairy ewes and goats}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {287-290}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {The prevalence and incidence of bacterial mastitis have not been determined for small milking ruminants in Vermont, USA. Milk samples were collected for bacteriology from each gland of 110 goats (6 herds) and 153 sheep (3 herds) within 24 hours of parturition and approximately 40 days later. The prevalence, incidence rate of new infection and the spontaneous cure rate were determined. Goats had a significantly higher prevalence of infection than sheep (P<0.05). Prevalance at parturition and 40 days later was 27.3\% and 25.5\% and 15.0\% and 9.1\% for goats and sheep, respectively. Prevalence of mastitis increased with age in goats (P = 0.08) but not sheep and differed among herds (P<0.05). It is concluded that there is variation among species and herds in the prevalence and incidence of mastitis}, issn = {1176-5283}, author = {McDougall S and Pankey JW and Delaney C and Barlow J and Murdough PA and Watts JL and Scruton D} } @conference {41217, title = {Prevalence of bacterial infection and somatic cell count of early postpartum milking goats}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {284-286}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {This trial aimed to identify the bacterial pathogens associated with caprine mastitis and to determine the prevalence of infection in early lactation. Milk samples for bacteriology and somatic cell count (SCC) were collected from both glands of 400 goats in four herds. Bacteria were isolated from 28\% (222/800) of the total glands sampled. Coagulase negative staphylococcus (12.9\%), Corynebacterium spp. (11.5\%) and Staphylococcus aureus (1.4\%) were the most prevalent isolates. Infected glands had a significantly higher SCC than uninfected glands (473 x 103 (399 -563 x 103) vs. 123 x 103 (112 -136 x 103), geometric mean SCC and 95\% confidence interval; P<0.05). Infection increased SCC and the degree of increase in SCC varied between pathogens }, issn = {1176-5283}, author = {Anniss F and McDougall S} } @conference {41181, title = {A program to assess the efficiencies of sheep-meat production systems: A teaching aid}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {135-138}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {A computer program written in Visual Basic within a spreadsheet was developed to illustrate how the efficiency of a sheep-meat production system varies when changes are made in any or all of 32 variables. System performance is expressed in monetary terms as either the efficiency (E) in dollars returns per dollar cost (with a break-even value of 1) or as a profit. Costs and returns for ewes, rams and lambs are taken into account, and all are expressed on a per ewe per year basis. A single per kilogram price for mutton is used, but for lambs, the proportion falling into various classes at any carcass weight is calculated using a specified GR/carcass weight relationship in a separate simulation program. Relationships within the E-program are based on published data, such as those in lamb feed requirement tables. This program has proved useful as an aid to evaluating some repercussions of making various combinations of changes to sheep-meat production systems. }, issn = {1176-5283}, author = {Purchas RW} } @conference {41183, title = {Reducing fat colour in beef by grazing steers on turnip bulbs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {143-146}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Feeding steers for 10 weeks on the residual turnip bulbs left after grazing the green tops off with lambs plus low carotenoid supplements, reduced carotenoid concentrations in the carcass fat by 38-43\% and fat colour by 14-31\% compared with steers grazing pasture. The steers on the turnip bulbs were fed a daily supplement of 0.5 x 10-1 IU of vitamin A in pelleted barley grain plus pasture silage, hay, and malting corms. The turnip bulbs comprised approximately 42-47\% of the diet. The growth rate of the steers on turnip bulbs was higher (P < 0.001) than for steers on pasture (0.71 kg head-1day-1 versus 0.45 kg head-1 day-1). There were no effects of grazing the steers on turnip bulbs on the other meat characteristics measured, including the odour and taste. }, issn = {1176-5283}, author = {Knight TW and Death AF} } @conference {41168, title = {The regulation of glycogen level in the muscle of ruminants by nutrition}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {94-98}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {This paper discusses recent work by the authors which has investigated the nutritional regulation of glycogenconcentration in skeletal muscle of sheep and cattle. Several experiments are summarised which show a clear relationshipbetween the level of glycogen in muscle and the intake of metabolisable energy. This translates into strong seasonal effectson the level of muscle glycogen in pasture fed cattle that correlate with live weight change. The clear message is thatanimals destined for slaughter should be on a high plane of nutrition as this will contribute to an increased level of muscleglycogen at slaughter and so help alleviate the problem of dark cutting meat. Acute regulation of glycogen is moreproblematical since the rate of glycogen repletion in skeletal muscle is relatively slow and the scope for rapid dietarychange in ruminants is constrained by the need to allow rumen adaptation to high starch/sugar diets. However the suddenintroduction of a high energy diet (based on cereal grain) in the presence of a {\textquoteleft}rumen modifier{\textquoteright} to reduce ruminal acidosiscan increase muscle glycogen concentration within 1 week of feeding. The ability to further modify glycogen level inskeletal muscle using carbohydrate and electrolyte products is discussed. In particular the possibility of using oral glycerol/propylene glycol as a means for increasing blood glucose and so glycogen synthesis is proposed. Experiments to examine the effectiveness of MgO as a means for reducing the stress response are also discussed.}, issn = {1176-5283}, author = {Pethick DW and Cummins L and Gardner GE and Jacobs RH and Knee BW and McDowell M and McIntyre BL and Tudor G and Walker PJ and Warner RD} } @conference {41175, title = {Relationship between intermediate pH toughness in the striploin and other muscles of the beef carcass}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {117-119}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Striploin (m. longissimus dorsi et lumborum) with ultimate pH values of 5.8 - 6.2 can be tough, and this toughness may persist despite prolonged ageing (> 45 days) although little is known about the effect of intermediate pH on other muscles. The aim of this work was to examine the relationship of intermediate-pH toughness in the striploin with other muscles. The shear force values were measured in seven muscles, collected from 20 heifers and aged at -1{\textdegree}C for 2, 7, 14, 30 or 60 days. The shear force of intermediate pH striploins after 2 days correlated with all other muscles except the chuck tender (m. supraspinatus) (Pm. longissimus thoracis) correlated with the striploin (P0.001). These results suggest that all muscles apart from the striploins and cuberolls from intermediate pH carcasses will tenderise to acceptable levels after 14 days of chilled storage. }, issn = {1176-5283}, author = {Simmons NJ and Auld MM and Thomson B and Cairney JM and Daly CC} } @conference {41187, title = {The relationship between wool follicle density and fibre diameter is curvilinear}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {162-165}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Records for wool follicle density and wool fibre diameter were obtained from ewes (n = 787) of 13 breeds and lambs (n = 543) of eight breeds and four crossbred combinations. The data were gathered as part of nine separate experiments from seven years. Mean fibre diameter ranged between 14 and 58 {\textmu}m, while follicle density covered the range 6.5 to 95 follicles/mm2. There was a significant curvilinear relationship (P < 0.001) between individual animal means for fibre diameter and follicle density. The relationship was significantly different between ewes and lambs (P< 0.001). Furthermore, the relationship between breed means for density and diameter were compared with equivalent data from literature sources. The relationship was effectively the same for all sources of data (P = 0.455). A restricted range of data could have led some literature sources to suggest a linear relationship! }, issn = {1176-5283}, author = {Scobie DR and Young SR} } @conference {41153, title = {Role of reproductive technologies in reducing the time lag associated with the commercial application of genetic discovery in the sheep industry}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {36-40}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {The recent and escalating emphasis on gene discovery has major implications for genetic improvement of the NZ sheep industry. However, the long lag phase in the dissemination of new genetic material through current breeding structures is a major impediment to rapid uptake of the improvements. Effective reproductive technologies are considered necessary for achieving the desired rates of dissemination but there is little evidence of their practical and economic values. To provide evidence, a series of modelling exercises were undertaken. This involved defining a particular commercial outcome (advancing the pattern of lamb kill in Otago/Southland by 1 month without changing lambing date), deciding on the relevant genetic trait to achieve this (terminal sires with a 20\% increase in mature size), modelling the rate of genetic gain using a number of breeding scenarios that included artificial insemination (AI) and multiple ovulation and embryo transfer (MOET), to determine the time required for sufficient commercial rams to be available to achieve the outcome. Selected scenarios were then chosen for more detailed modelling to ascertain the economic implications to the farm (Otago/Southland lamb finishing farm) and to the industry of adopting the technology. The advancement of the kill pattern by one month was worth $12,714 on the commercial farm. Based on a two-tiered breeding system (stud and commercial) without any reproductive technology it takes 26 years to achieve the outcome (assuming that the animal with this genetic advantage had been identified at the start). The use of AI at the stud level reduced this time by 11 years. The additional use of MOET on stud ewes gave a further reduction in time of 7 years and the application of AI using stud rams at the commercial level an additional 2 years. These results confirm the importance of reproductive technologies in reducing the lag phase in gene dissemination and their value to the industry. There is a need to further refine the efficiency and efficacy of the chosen technologies. }, issn = {1176-5283}, author = {Smith JF and Vetharaniam I and McCall DG and Tervit HR} } @conference {41215, title = {Rumen foam stability in cattle selected for low or high bloat susceptibility}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {277-280}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {A simplified method to measure foam volume (V infinity) and stability (1/k2) was used to investigate the influence of saliva on foam properties and its relationship to bloat susceptibility. Significant differences in V infinity and 1/k2 were observed between samples of rumen fluid (within-sample CVs were 9\% and 18\%, while between sample CVs were 57\% and 70\% for V infinity and 1/k2, respectively). Mixing bovine saliva with rumen fluid or diluted clover juice resulted in a large increase in V infinity and 1/k2 (4.6- and 7.8-fold, respectively). This effect was strongly synergistic as saliva alone produced essentially no foam. The assay was used to quantify the efficacy of a paraffin-based anti-bloat drench (V infinity and 1/k2 were decreased by up to 4-fold and 6-fold, respectively). Saliva from non-bloating cattle, four each from herds bred for low- or high-bloat susceptibility, was measured for the effect on the foam parameters of a rumen fluid sample. No significant differences due to herd-of-origin were observed. }, issn = {1176-5283}, author = {Hurd SA and Wheeler TT and Morris CA} } @conference {41172, title = {Search for a locus near to myostatin that increases muscling in Texel sheep in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {110-112}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {In close collaboration with three Texel breeders, we initially genotyped 36 rams with 5 DNA microsatellite markers that are known to map around the myostatin gene in sheep. Of these 36 rams, progeny of 12 polymorphic sires (4 from each flock) were selected for further analysis. This selection was made on the basis of each sire producing more than 40 offspring which were accompanied by parentage records, live weights at weaning and 8 months of age, and ultrasonic measurements of fat depth and rib-eye muscle dimensions. Final progeny numbers from the sires chosen ranged from 45 to 115 per sire. The data was analyzed by regressing the observed measurements on the probability of which paternal grandparental chromosome was inherited at the myostatin locus. The results suggest that the region of the sheep genome near the myostatin locus affects muscling (P<0.05) and fat depth (P<0.05) in the progeny of 4 of 12 sires tested. }, issn = {1176-5283}, author = {Broad TE and Glass BC and Greer GJ and Robertson TM and Bain WE and Lord EA and McEwan JC} } @conference {41226, title = {Seasonal variation of the fatty acid composition of milkfat from Friesian cows grazing pasture}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {314-317}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Information collected at the Dairying Research Corporation milk composition laboratories on the fatty acid composition of milkfat spanning 1994/95 to 1998/99 dairying seasons has been summarised. The data comprised 1350 determinations in 18 different experiments from 965 individual Friesian cows that calved in July/August and grazed solely on pasture. A seasonal effect on fatty acid composition was observed. In general, concentrations of fatty acid groups and individual fatty acids were similar in spring and autumn but differed in summer. The ratio of an estimate of preformed (total fatty acids >C 17:0 ) and an estimate of de novo- (total fatty acids 1 mmol/L during Weeks 1\&2 pp, compared to 52\% of other cows (P < 0.1). Levels of pBOH alone could not predict the length of the PPAI (r2 = 2\%). Logistic regression analyses confirmed age, calving live-weight and calving condition score as risk factors for prolonged PPAI. When these factors were considered with pBOH at Weeks 5\&6 pp, a predictive relationship was found (P < 0.05). Levels of mBOH and pBOH were related (r2 = 0.68; P < 0.001). These results support negative energy balance in early lactation as a risk factor for prolonged PPAI, along with age and live-weight and body condition score at calving.}, issn = {1176-5283}, author = {Verkerk GA and Guiney JC} } @conference {41080, title = {CF2000 - a new way of looking at the same information}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {79-81}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The CF2000 farm monitoring programme enables farmers to monitor factors relevant to their property and management, as well as enabling comparisons to be made with other members of the group through benchmarking. Data recording is divided into a compulsory core section and an optional section. Data is processed by a bureau, and the reports which include a variety of graphs showing an individual’s performance relative to the group, are returned to participating farmers along with comments from the farm-ers’ consultant. Members-only field days are held three times per year for educational and motivational purposes.}, issn = {1176-5283}, author = {McCorkindale AB} } @conference {41070, title = {Changes in unscourable discolouration of Romney wool samples during storage for one month}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {49-51}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Samples of four Romney fleeces were dried to 8\% moisture immediately after harvesting, then water was added to achieve moisture contents of 8, 19, 30, 41 or 52\% of the clean, dry wool weight. Additional samples were left untreated (11 \% moisture) or scoured (16\% moisture). CIE X, Y, Z and Y-Z measures of scoured wool colour were recorded after 0, 5, 12, 21 or 33 days storage at 3 or 20{\textdegree} C. There was no change in colour values of untreated and scoured samples during storage at 3 or 20{\textdegree} C. X, Y and Z values decreased linearly when moisture content increased (P<0.05), the effect being most marked at 20{\textdegree}C. A trend for Y-Z values to increase with moisture content was not significant. The findings indicate that if damp greasy wool is to be stored for a month or more before colour is measured, it should be dried at 30{\textdegree}C or less before storage, stored at cool temperatures, or scoured and dried before storage. }, issn = {1176-5283}, author = {Bray AR and O{\textquoteright}Connell D and Smith MC} } @conference {41094, title = {Compensatory growth in lambs undernourished from birth}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {111-113}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {There is evidence to suggest that lambs on restricted nutrition from birth fail to show compensatory growth. In this indoor trial, lambs were allocated to one of three treatments and fed on lamb milk formula, then sheep pellets. Lambs were started on high (H) or low (L) rates of intake from 3 days of age. Groups of L lambs were subsequently placed on H intakes (low-high; L-H) at 2, 4 and 8 months of age and killed at 4, 8 and 15 months of age respectively. At 15 months H lambs weighed 86.2 kg and L lambs 28.6 kg. The growth rates of L-H ranged between 224 and 242 g/d during compensatory growth. The H lambs averaged 186 and L lambs 50 g/d during the experiment. At slaughter, there was no difference between H and L-H lambs for hot carcass weight when adjusted for final live weight, and little change in the weight and length of M. semitendinosus. Hind limb dissection also demonstrated no effect of nutritional treatment on proportions of muscle, bone and fat in H and L-H lambs. These results suggest that lambs on restricted nutrition from birth retain their potential to grow if provided with improved nutrition.}, issn = {1176-5283}, author = {Bass J and Kirton A and Oldham J} } @conference {41091, title = {Contract References}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {103}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {CONTRCT REFERENCES Agricultural Research Council. 1980 The nutrient requirements of rumi-nant livestock. Commonwealth Agricultural Bureaux, Farnham Royal, England. Anon, 1999. The New Zealand sheep and beef farm survey 1996-97. Meat and Wool Economic Service of New Zealand. 71pp. Chamberlain, D.G.; Martin, P.A.; Robertson, S. 1996. Optimising com-pound feed use in dairy cows with high intakes of silage. Recent Developments in Ruminant Nutrition 3: 245-263. Dalton, D.C.; Knight, T.W.; Johnson, D.L. 1980. Lamb survival in sheep breeds on New Zealand hill country. New Zealand Journal of Agricultural Research 23: 167-173. Davis, G.H.; Kelly, R.W.; Hanrahan, J.P.; Rohloff, R.M. 1983. Distribu-tion of litter size within flocks of different levels of fecundity Proceedings of the New Zealand Society of Animal Production, 43: 25-28. }, issn = {1176-5283}, author = {Anonymous} } @conference {41071, title = {Dag formation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {52-54}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Dags are a major cost in sheep farming. This paper reports on differences in wool yield and mineral content of faeces associated with dag formation. Of 600 hoggets on a farm in Inland Canterbury, only three had dag scores greater than 0.5 in mid-March (mean dag score 0.030). After 10 weeks (mean dag score 0.4), 80\% of the animals recorded a dag score 0.5 or less and 40 animals (6.7\%) had dag scores of 2 or greater. In two other trials, wool samples showed no differences in wool grease, suint content or yield associated with differences in dagginess of the animals. Fresh faeces were collected from ewes from the Resistant (R) and Susceptible (S) FEC selection lines at Wallaceville which differ in dag formation. These lines did not differ in faecal dry matter, phosphorus, calcium, magnesium, sodium or potassium content. Lambs from these lines differed significantly in faecal potassium (mean = 13.8 mg/kg, R-S = 2.98 mg/kg (P<0.001)) and magnesium (mean = 5.7 g/kg, R-S = -0.82 g/kg (P<0.05)) contents. Faeces from lambs grazing low or high endophyte pasture also differed in potassium (12.8 vs. 15.3 g/kg, SED 1.18) and magnesium (7.6 vs. 6.0 g/kg, SED 0.67) content. These results point to differences in faeces associated with differing dag forming tendencies and may assist in explaining some of the mechanisms involved in dag formation. }, issn = {1176-5283}, author = {Cottle D and Reid TC} } @conference {41067, title = {Development of fibre and follicle characteristics related to wool bulk in hoggets of genotypes used to develop GrowBulk sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {39-42}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Wool fibre and follicle development was monitored in 40 hoggets born in 1996 comprising sex-balanced groups of Romney (R), Dorset x Romney (DR), Texel x Romney (TR) and DR x TR and TR x DR (DTR) sheep between 3 and 12 months of age. There was a significant curvilinear pattern of development for fibre curvature and follicle curvature for the DR, TR and DTR groups whereas values for the R group did not change significantly with time. Fibre diameter was not significantly different between the groups. A combination of fibre curvature and fibre diameter explained approximately 70\% of the variation in core bulk within all genotypes at hogget shearing for samples taken at points in time during growth of the fleece. The combination of fibre curvature and fibre diameter is a useful predictor of adult wool bulk to assist breeders of GrowBulk sheep. }, issn = {1176-5283}, author = {Sumner RMW} } @conference {41138, title = {Discriminating among animals for improved rewards from traditional meat cuts}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {269-271}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The influence of biological variation on animal numbers meeting specifications based on alternative indicators of carcass merit to GR and carcass weight (CW), and the value of live animal indicators in meeting particular goals were investigated. Percentages of carcasses achieving a two-trait (GR: 5.5 to 9.5mm; and CW: 15.5 to 17.5kg) and a three-trait (GR, CW and various leg lengths: T) specification were analytically derived over multivariate normal distributions. Two {\textquoteleft}populations{\textquoteleft} of sheep were considered; one with a mean CW, GR and T of 14.6kg, 6.8mm and 184mm, respectively, and the second with mean values of 15.5kg, 6.8mm and 186mm. Adding conformational traits reduced the proportion achieving the specification, with the reduction being greater if the correlations between traits were antagonistic. Analysis of potential carcass merit indicators from experimental dissection data indicated that 8\% of the variation in leg weight was associated with sire breed, sire, sex and birth rank effects, while 32\% was associated with animal variations in six linear indicators (high GR, low subcutaneous leg fat depth, high carcass length, T, high proximal leg circumference, and low total length of the leg joint). Together these two classes of indicators accounted for 36\% of the total variation among lambs. }, issn = {1176-5283}, author = {Jopson NB and Clarke JN} } @conference {41140, title = {A Dynamical Model of Body Composition in Sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {275-278}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A dynamical model describing the evolution of muscle, viscera and fat in response to different levels of energy intake over time in sheep is presented. The model shows responses consistent with observations of compensatory growth in sheep and cattle over a range of energy intake levels. Model parameters are derived from data measured by Ferrell et al., (1986) to investigate compensatory growth in lambs. The model is shown to generally reproduce the behaviour of the muscle, viscera and fat components of the lambs in this trial. The utility of the model for designing optimal nutritional management strategies for raising animals for slaughter is discussed, as well as the potential of the model to advance the understanding of animal nutrition by investigating different functional forms for relationships such as maintenance requirements. }, issn = {1176-5283}, author = {Soboleva TK and Oddy VH and Pleasants AB and Oltjen JW and Ball AJ and McCall DG} } @conference {41110, title = {Effect of long acting injectable vitamin B12 on the vitamin B12 status of the suckling lamb}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {168}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Treatment of lambs with a long acting microencapsulated injection of 3mg and 6mg Vitamin B12 at 3 to 4 weeks of age, at docking, will increase and maintain their Vitamin B12 status for at least 120 days. This new product has the advantage over intraruminal Co bullets which can only be administered to 10 to 12 week old lambs with a functional reticulorumen while the injectable water soluble Vitamin B12 is only effective for about 4 weeks and a Co drench is effective for about 10 days. }, issn = {1176-5283}, author = {Grace ND} } @conference {41106, title = {Effect of Lotus corniculatus and condensed tannins on milk yield and composition of dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {152-155}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Experiments at DRC have demonstrated birdsfoot trefoil (Lotus corniculatus) increases milk yield and milk protein concentra-tion of grazing dairy cows. An experiment was conducted in March 1998 to determine what proportion of the increased milk yield and milk protein\% was due to the condensed tannins (CT) in Lotus, and what proportion was due to factors typically associated with legumes (increased herbage intake and improved forage quality). Twenty Friesian cows were housed and fed twice daily on either perennial ryegrass or Lotus for 10 days. Five cows on each diet were also drenched with 1.2 l of 50\% polyethylene glycol (PEG) three times per day. PEG blocks the action of CT, preventing them binding to plant proteins. Milk yields (l/cow/d) were higher on Lotus (16.5) than on Lotus+PEG (13.8), ryegrass (10.2) or ryegrass+PEG (9.9) indicating that CT contributed to 42\% of the increased milk yield that resulted from feeding Lotus rather than ryegrass. CT had no effect on intake, since intakes (kgDM/cow/d) of cows fed Lotus (16.8) and Lotus+PEG (16.7) were similar and higher than for cows fed either ryegrass (14.7) or ryegrass+PEG (13.7). CT, however, accounted for all of the increase in herbage conversion efficiency as indicated by the higher efficiencies (ml FCM/MJ ME) of cows fed Lotus (147) compared with those fed Lotus+PEG (126), ryegrass (123) or ryegrass+PEG (127). CT accounted for 57\% of the increase in milk protein\% as cows fed Lotus (3.61) had higher protein\% than those fed Lotus+PEG (3.44), ryegrass (3.31) or ryegrass+PEG (3.30). Herbage or CT had no effect, however, on the casein or whey protein concentrations. CT had no effect on either milk fat or lactose concentration but cows fed Lotus had lower concentrations than cows fed ryegrass (P<0.05). Overall the trial showed legumes containing CT have potential as a forage for dairy cows.}, issn = {1176-5283}, author = {Woodward SL and Clark DA and Laboyrie PJ and Jansen EBL} } @conference {41062, title = {Effect of recipient breeds on birth and weaning weight, and wool follicle characteristics of Merino lambs born by embryo transfer}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {19-22}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {One hundred and eighty three embryos were collected from 29 donor Merino ewes and transferred as either a single or twins to Merino (MR), Coopworth (CR) and Romney (RR) recipient dams. A total of 107 lambs were weaned from these implants. A control group (MN) of 24 naturally conceived single and twin lambs were included for comparison. Follicle fibre diameters at birth were 16.7, 17.2, 17.7 and 17.6 mm (SED 0.4) for MN, MR, CR and RR respectively; while the fibre diameter of wool samples at birth for all dam groups was 16.5 mm (SED 0.3). Follicle fibre diameters at weaning were 16.5mm, 15.9, 16.3 and 16.1 (SED 0.6) for MN, MR, CR and RR respectively while the corresponding wool FDs at weaning were 16.3 mm, 16.1, 16.0, and 16.0 (SED 0.4). Weaning weight was similar in CR and RR, while CR weaned significantly heavier lambs than Merinos (recipients or naturally bred). The results suggest that crossbred dams improve weaning weights of Merino lambs born to embryo transfer but do not affect their wool follicle character-istics.}, issn = {1176-5283}, author = {Wuliji T and Dodds KG and Andrews RN and Aspinall J and Harrison T} } @conference {41064, title = {Effect of selection for fleece weight on liveweight, reproductive performance and wool characteristics in mixed age Romney ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {27-29}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {This paper presents the analysis of 3525 annual production records of mixed age Romney ewes in a fleece weight selected (HF) or control (RC) flock over 11 years. HF ewes were significantly (P<0.001) heavier than RC ewes for autumn live weight (8\%), winter live weight (9\%), spring live weight (7\%), greasy fleece weight (20\%) and clean fleece weight (19\%). Small but significant (P<0.01) flock differences were found for fibre diameter and yellowness. HF fleeces were coarser and more yellow than RC fleeces. HF ewes were significantly (P<0.01) higher than RC for ovulation rate (1.80 vs 1.73 SED 0.03), number of lambs born/ewes lambed (1.63 vs 1.56 SED 0.02), and number of multiple births/ewes lambed (60\% vs 54\% SED 2\%), but lower (P<0.01) for number of lambs weaned/lambs born (0.84 vs 0.88 SED 0.01). The results indicate that single trait selection for fleece weight enhances greasy and clean fleece weights, live weight and ovulation rate, with an associated increase in FD and yellowness of their fleeces. }, issn = {1176-5283}, author = {Wuliji T and Dodds KG and Andrews RN and Turner PR and Wheeler R} } @conference {41125, title = {Effect of very low sperm doses on pregnancy rates after AI in sheep.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {219-222}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Low sperm numbers and ambient temperature storage are two important factors in the successful AI system for dairy cattle in New Zealand. A critical evaluation of these factors with ram semen is required before the establishment of a similar AI system within the NZ sheep industry is feasible. A trial involving a total of 1262 Romney ewes was conducted in April 1998 to examine the effects of inseminate dose (25, 5, 1 and 0.5 x 106 sperm) of semen held for up to 9 h at 20{\textdegree}C in two diluents (RSD-1 and RSD-8). Ewes, synchronised with 3 types of CIDR devices were laparoscopically AI{\textquoteleft}ed with semen from either a Finn or a Romney ram at set times (49 or 56h) after CIDR removal. AI was spread over 4 days in each of two consecutive weeks. Rams were used on each alternative day. Ewes were checked for return to service to determine pregnancy. There was a significant (P<0.001) difference between rams in pregnancy rate (Finn =35.6 and Romney =52.5\%). There was an effect (P<0.001) of inseminate dose (25 = 55.5 {\textpm} 2.6\%; 5 = 45.2 {\textpm} 2.6\%; 1 = 37.2 {\textpm} 2.6\% and 0.5 = 37.5 {\textpm} 2.6\%). However there was a suggestion of an overall dose by ram interaction with the Romney semen maintaining higher fertility at lower dose levels. There were no effects of inseminator or of diluent. Time from CIDR removal to oestrus had a significant (P<0.05) effect. Time to onset of oestrus was affected by CIDR type. While there was no overall effect of CIDR type on fertility, there was a significant (P<0.05) interaction between sperm dose and CIDR type. These results indicate that acceptable (>50\%) fertility can be achieved with sperm dose rates as low as 1.0x106 if semen quality is satisfactory thus increasing the number of inseminates per ejaculate 20-50 fold. Improved synchrony methods seem imperative to obtaining better fertility from AI. }, issn = {1176-5283}, author = {Smith JF and Parr J and Murray GR and Clarke A and Oliver JE and McDonald RM and Duganzich DM} } @conference {41136, title = {Effects of ergovaline in endophyte-infected tall fescue on ewe fertility}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {263-265}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Ergovaline is one of the major toxins produced in tall fescue and perennial ryegrass pastures infected with wild type endophyte fungi. Animals grazing these pastures often have reduced productivity and in some cases lower reproductive performance. To date very little is known about the effects of ergovaline on sheep and in particular sheep fertility. A trial was conducted consisting of two groups (n = 20) of synchronised, Finnish landrace x Romney 2-tooth ewes. The groups were grazed on either of two lines of endophyte-infected tall fescue, one producing ergovaline (EV+) and the other ergovaline free (EV-) for two weeks and then mated on the treatments. Ovulation rate, conception rate, and numbers of lambs carried were recorded. Levels of serum prolactin and ergovaline in the pasture were determined. Ergovaline levels in the herbage were 3.30 {\textpm} 0.60 mg/g and 0mg/g in the EV+ and EV- pastures, respectively. Ewes grazing the EV+ treatment had significantly lower (P<0.05) ovulation rates and number of lambs carried to 90 days of pregnancy than the EV- group. Serum prolactin was significantly (P<0.001) reduced in the EV+ group. These results indicate that similar effects could be exhibited in ewes grazing endophyte-infected perennial ryegrass pastures containing ergovaline and further trials are being undertaken to examine this possibility. }, issn = {1176-5283}, author = {Kramer R and Keogh R and McDonald MF} } @conference {41092, title = {Effects of herbage mass and ewe condition score at lambing on lamb survival and liveweight gain}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {104-107}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Scanned, twin-bearing mixed aged ewes (n=1276) were set-stocked (7.5 {\textpm} 0.1 ewes ha-1) over the lactation period at either high or low condition score (CS) (2.51 vs 1.52) and high or low herbage mass (HM) (1160 vs 880 kg DM ha-1 ) in an experiment replicated on 5 farms in Wairarapa. Three farms lambed early (27 August to 4 September 1997) and were summer-dry and two lambed later (22 to 27 September 1997) and were summer-wet. High ewe CS may have improved lamb survival (167 vs 150\%, P=0.13) through reduction in estimated lamb mortality (17 vs 25\%, P<0.01) on late lambing farms where weather conditions were adverse at lambing, but had no effect on early lambing farms where lambing conditions were more favourable. Ewe CS had no effect on either lamb or ewe LWG. High HM may have reduced lamb mortality on early lambing farms (10 vs 14\%, P<0.05) where ewes were under greater nutritional stress than on late farms. Additional HM at set-stocking increased lamb LWG up to docking by 11 g d-1 per 100 kg DM ha-1 increase (P<0.03) on early farms but had no effect on late farms. Lamb LWG from docking to weaning was unaffected by set-stocking HM. The overall effect of an increase in set-stocking HM by 100 kg DM ha-1 was to increase lamb weaning weight by 2 kg on early farms. Additional HM at set stocking increased ewe LWG from birth to docking by 33 g d-1 per 100 kg DM ha-1 increase (P<0.001) but decreased LWG from docking to weaning by 18 g d -1 per 100 kg DM ha-1 increase. This response was similar on early and late lambing farms. On early farms there was a net increase in ewe liveweight at weaning of 1.6 kg for each 100 kg DM ha -1 increase in lambing HM. }, issn = {1176-5283}, author = {Lambert MG and Litherland AJ and McLaren PN} } @conference {41118, title = {The effects of stressors on lymphocyte populations and function in lactating dairy cows.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {195-197}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Increased stress in animals can lower immune system function and hence decrease resistance to disease. The objectives of the study were to determine the effects of two stressors on lymphocyte function in lactating dairy cows. Jersey cows were allocated to four, 7-day treatments in a 2 x 2 factorial plan. The factors were level of feeding (4\% bodyweight vs 3\% bodyweight) and lying time (free choice lying vs prevention of lying from 1500 to 0645 h daily). Blood samples collected during the pre-treatment and treatment periods were analysed for in vitro lymphocyte proliferative response and sub-populations. Lymphocyte proliferative response was not affected by feed level or lying time. Only minor changes occurred in lymphocyte sub-populations. Within the fully-fed cows, lying deprivation resulted in a greater proportion of CD8 (suppressor) cells. These data indicate that lymphocyte function in lactating cows may not be compromised by medium term restrictions in feeding and lying, and that any stress-induced decreases in cell-mediated immunity which occur in practice, are the result of more severe, or prolonged, conditions. }, issn = {1176-5283}, author = {Fisher AD and Verkerk GA and Stevenson RA and Wesselink E and Morrow CJ and Matthews LR} } @conference {41117, title = {The effects of stressors on milk composition in dairy cows.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {192-194}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The effects of two stressors (level of feeding: 4\% bodyweight, FI, and 3\% bodyweight, RI; and altered lying time: free choice, LF, and prevention of lying from 1500 to 0645 h daily, LD) allocated in a 2x2 factorial design on milk yield and composition of Jersey cows (n=32) were studied. Stressors were applied for 7 days following an 8-day pre-treatment period. Composite milk samples were collected at milkings on days 2-3 of pre-treatment and during the last 4 days of treatment. Fat\%, milk weight (am, pm and total daily) and mean daily yields of fat, casein, lactose and total milksolids were not affected by treatment. Protein\%, protein yield and casein\% were lower with RI (protein\%: 3.66 and 3.53, sem=0.02, P<0.01; protein yield: 0.54 and 0.50 kg, sem=0.01, P=0.05; casein\%: 2.84 and 2.77, sem=0.02, P<0.05 for FI and RI, respectively). There were no significant interactions between treatments. Protein content of milk was reduced by medium-term feed restriction, but lying deprivation had minimal effects. }, issn = {1176-5283}, author = {Verkerk GA and Fisher AD and Morrow CJ and Matthews LR} } @conference {41123, title = {Embryo and recipient contributions to pregnancy loss following the transfer of cloned embryos derived from foetal and adult somatic cells}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {211-215}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The purpose of this paper is to report on the reproductive outcomes following the transfer of cloned bovine embryos produced following somatic cell nuclear transfer. All recipients received two embryos. In Expt 1 (19 recipients), donor cells were derived from a 34 day old female foetus, while adult cows were used as the genetic donors in both Expt 2 ({\textquoteleft}Lady{\textquoteleft} from Enderby Island, 38 recipients) and Expt 3 (Elizabeth, a high genetic merit Friesian, 56 recipients). Overall, embryo survival rate to term was 12\%, with little affect of experiment. This compares unfavourably with the reported 30-35\% survival rate to term in embryos generated using in vitro production procedures without nuclear transfer. Of all transferred embryos, 36\% were competent to survive to term. Furthermore, only 36\% of the recipients were competent enough to support a pregnancy to term. We conclude that actual embryo survival is lower with nuclear transfer and IVP technology because both embryo and recipient competence is compromised. }, issn = {1176-5283}, author = {McMillan WH} } @conference {41079, title = {Establishment of a farm monitoring scheme for sheep farms}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {77-78}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {CF2000 (Clutha Farms 2000), and now NZFT2000 (New Zealand farm technology 2000), make big changes in sheep farm management and business skills available to the individual farmer on his own farm in easily understood, easily workable, and low cost form. The basis of management changes has changed from those based on traditional subjective and often anecdotal information, to a management system where decisions are made on factual timely information backed by latest technology and business abilities.}, issn = {1176-5283}, author = {Shaw CA} } @conference {41112, title = {The Evolution of Liveweight Variance in Angus Steers and Strategies for Control.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {173-176}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The effect of year of birth and nutritional treatment on liveweight variance in mobs of Angus steers from birth until approximately 30 months-of-age is examined. Significant (P<0.01) differences in liveweight variance at 30 months-of-age were recorded between years. The environment of the calves over the first 20 days of life appeared to affect the development of mob variance, steers which experienced early life on a sawdust pad showing higher variance at 30 months-of-age in liveweight and carcass weight. Restricted nutrition during the first winter of the steer{\textquoteleft}s life was associated with a significantly (P<0.05) higher variance in 30 month liveweight (standard deviation 24.0 v 37.8kg). Within mob, lower rates of liveweight change were associated with an increase in liveweight variance (r = -0.72). A mathematical model was used to assess the effects of controlled mating strategies on mob variance. Minor improvements were possible. The implications of controlling mob variance for farm quality assurance management is discussed. }, issn = {1176-5283}, author = {Pleasants AB and McMillan WH and Barton RA} } @conference {41086, title = {Ewe nutrition: decisions to be made with scanning information.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {93-94}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The ultrasonic scanning technology has provided farmers with a useful tool to determine potential lambing percentages well in advance of lambing. This paper outlines ways in which this information can be used to effectively target groups of ewes to maximise feeding efficiency. Underfeeding of the ewe flock can be partly alleviated by the early sales of non-pregnant ewes. Understanding the interactions between body condition and feeding in conjunction with scanning can lessen birthing problems through appropriate feeding regimes. Targeted feeding plans can ensure that both protein and energy needs are met for single, twin and triplet bearing ewes. Feed types such as brassicas, silage and grain can be targeted to specific periods throughout the pregnancy for optimal feed use once parity is known. }, issn = {1176-5283}, author = {Stevens DR} } @conference {41085, title = {Experiences of a pioneer in the commercial sheep pregnancy scanning business}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {91-92}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Since 1991, ultrasonic pregnancy scanning has developed from a tool used initially to identify dry ewes, into one that accurately identifies ewes carrying singles, twins and triplets. The use of scanning to determine litter size has expanded from stud flocks into a large proportion of commercial flocks. Satisfying the demand for pregnancy scanning has in eight years grown into an industry that employs about 90 scanner operators in the South Island during the peak of the season. Scanning is well established as a vital tool for the monitoring and management of breeding ewes. }, issn = {1176-5283}, author = {Farmer RJ and Davis GH} } @conference {41105, title = {Factors affecting behaviour, bruising and pHu in a deer slaughter premises}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {148-151}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Data from an on-going study at a deer slaughter premises were analysed. Over one year 3856 deer, primarily red x wapiti hybrids, from 101 farms were observed. During overnight lairage a mean of 14 (s.d. 7.6) antagonistic encounters/hr occurred. In the race immediately prior to stunning, rearing was the most common form of unsettled behaviour (17\% of deer). The incidence of unsettled behaviour differed between carriers (P<0.001). Bruising occurred in 24\% of carcasses, increased with load size (P<0.01) and poor weather conditions (P<0.05), and differed between carriers (P<0.05). Half (48\%) of all bruises were small and less than 5mm deep. Mean ultimate pH (pHu) was 5.65 (s.d. 0.139), and moderate-high pHu (>5.8) was prevalent in the shoulder (18.5\% of carcasses) followed by the loin (10.6\%) then the leg (5.6\%). Behaviour, bruising and pHu all differed significantly between farms and days (P<0.001). }, issn = {1176-5283}, author = {Pollard JC and Stevenson-Barry JM and Littlejohn RP} } @conference {41078, title = {Farm and Flock Monitoring - Introduction}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {76}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {in recent years, sheep farmers have embraced farm and flock monitoring as techniques to increase the profit-ability of their business. Clutha Farms 2000 (CF 2000) was established in South Otago to enable sheep farmers to monitor the performance of their farms. The standard re-cording format applied to each member’s farm has been the basis of benchmarking, whereby each member can com-pare their farm’s performance against that of other mem-bers farming in a similar environment. The early success of the scheme has encouraged other regions to set up simi-lar schemes and an umbrella organisation, FT 2000, has been formed to co-ordinate and encourage new groups throughout New Zealand. Ultrasonic pregnancy scanning as a quick and reli-able technique for identifying the number of foetuses car-ried by each ewe has opened new opportunities for the management of breeding flocks. The ability to separate mobs of ewes according to their pregnancy status has al-lowed farmers to run multiple-bearing ewes with greater confidence. Pregnancy scanning has also improved the monitoring of flock performance by highlighting losses between mid-pregnancy and tailing. For farmers who were previously unaware of the magnitude of their neonatal lamb mortality, the capacity to accurately measure this loss has motivated them to make greater effort to improve lamb sur-vival. An index relating scanning percentage to mating liveweight has been a useful basis for benchmarking flock prolificacy. This contract draws on the experiences of those who had a pioneering role in establishing farm and flock moni-toring, those who in various ways provide monitoring serv-ices, and farmers who use and benefit from monitoring. In keeping with the location of this year’s annual conference, the contract has a heavy southern bias, but as farm and flock monitoring are becoming increasingly available through-out New Zealand there is the potential to significantly im-prove the production and profitability of the entire sheep industry.}, issn = {1176-5283}, author = {Davis GH} } @conference {41081, title = {Farm financial monitoring}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {82-83}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The financial data gathered by Shand Thomson \& Co has highlighted the gap between the average and the top 10\% or top 25\% of farmers. The sharing of this information among farmers helps individuals identify the strengths and weakness of their usiness and is an important step in making the changes required to increase profitability.}, issn = {1176-5283}, author = {Johnstone WJ} } @conference {41142, title = {Farm of origin and finishing environment effects on beef quality attributes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {282-286}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {An experiment was conducted to test the hypothesis that finishing environment can affect beef quality attributes, including fat and meat colour, meat pH, subcutaneous fat depth (FD) and intramuscular fat (IMF) content of pasture-fed beef. 181 rising 2-year old Angus steers were obtained from 4 source farms and finished at 4 North Island locations. On 3 properties, home-bred cattle were compared to a common control line. On a fourth property, cattle from the 3 sources were compared to each other and to the control. FD, meat pH and meat colour were affected by location (P<0.01), but not source. Only source effects were significant (P<0.05) for IMF. Both source and location affected fat colour (P<0.01). Steers that were killed later had significantly (P<0.01) higher meat pH (r=0.33), darker meat (r=-0.24), greater IMF (r=0.26), higher plasma carotene levels at slaughter (r=0.38) and yellower fat b* (r=0.39). The results indicate that both farm of origin and finishing environment can affect meat quality. Both sources of variation appeared to be mediated, in part, by cattle growth rate. }, issn = {1176-5283}, author = {Smith DR and Smith NB and Muir PD} } @conference {41059, title = {Farm performance measurement - Linking monitoring to business strategy}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {6-13}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Farm monitoring and evaluation are elements within the control function of management. Control is directly linked to planning: through planning performance, targets are set and outcomes are measured and assessed relative to these. The use of formal monitoring by farmers has been lower than expected. To redress this, more emphasis is now being placed on tying farm performance measures (or indicators) to business strategy. The aim is to transparently connect day-to-day (operational) management to the goals of the manager/ owner. This shift in the focus of farm monitoring and evaluation concentrates performance measurement around a limited number of factors that are critical to the successful execution of strategy. Data collection and analysis is therefore directly integrated with adding value to the farm business. It also facilitates the correct application of benchmarking to continually improve performance through farmer learning. The balanced scorecard provides a mechanism to integrate farm monitoring results with farm mission, strategy and target performance in a condensed and easy to read format. This should further encourage farmers to monitor and benchmark their production and management systems in order to gain feedback for evaluating decisions (learning) and help them to continually update their strategy to sustain high performance.}, issn = {1176-5283}, author = {Parker W} } @conference {41083, title = {Farmer experience of farm monitoring}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {85-86}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Farm monitoring has played a key role in the dramatic increase in our farm production since 1995/96. Through farm monitoring we are now much more aware of the current performance levels of our flock. The basis for decision making has been greatly improved by having more factual information on livestock performance. Androvax and crossbreeding have been identified as the means to rapidly improve our lamb production}, issn = {1176-5283}, author = {Miller JR and Miller GL} } @conference {41088, title = {Farmer use and experience of ultrasonic pregnancy scanning}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {97-98}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Ultrasonic pregnancy scanning has enabled better feed allocation and lambing management of our breeding flock. In the past two years, scanning has also identified many of the triplet-bearing ewes but there is a need to develop more effective systems for managing these ewes. We attribute much of the 18\% increase in lambing percentage over the past four years to improved management based on scanning results. Scanning also has benefits in the genetic improvement of the flock and we envisage in the near future selecting all replacements from twin-bearing and triplet-bearing ewes that have lambed as hoggets and subsequently never had more than one single birth.}, issn = {1176-5283}, author = {McAtamney TJ and McAtamney S} } @conference {41131, title = {Fertility control of possums: The search for regulators of gonadal development and pituitary function}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {239-244}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The Possum Research Programme of the Reproductive Biology Group at the Wallaceville Animal Research Centre is focused in four specific areas, namely: (a) identifying growth factors and hormones associated with gonadal development during the first 200 days of life; (b) searching for possum homologues of a riboflavin carrier protein (RCP) and a gut epithelial receptor/transporter protein (FcRn); (c) elucidating the role of gonadotrophin-releasing hormone (GnRH) on pituitary gonadotrophin secretions and; (d) producing and testing reagents which might interfere with gonadal formation and function of the pituitary gland. Possum specific reagents and in vitro test systems have been developed and will be used to develop strategies for fertility control. }, issn = {1176-5283}, author = {Eckery DC and Fidler AE and Moore LG and McNatty KP} } @conference {41089, title = {Field data analysis of lamb survival and mortality rates occurring between pregnancy scanning and weaning}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {98-100}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Ultrasonic scanning for pregnancy diagnosis in commercial sheep flocks has highlighted the magnitude of lamb loss from scanning to docking or weaning. From seven ram breeding flocks in Landcorp Farming Limited, lamb survival rates were derived from the number of lambs per ewe present at six stages: pregnancy scanning, birth, born alive, 48h after birth, end of lambing and weaning. Differences in lamb survival rates between adjacent stages provided the mortality rates for five intervals: pregnancy scanning-birth; birth-born alive; born alive-48h after birth; 48h after birth-end of lambing; end of lambing-weaning. Flock-year affected lamb survival rate at all stages (P<0.001) but varied with ewe age and lamb birth/rearing rank (P<0.001). Mean lamb survival rates for 3- and 4-year-old dams were generally higher than those of other dam age groups. Triplet-reared lambs had consistently lower survival rates than single- or twin-reared lambs (P<0.001). Lamb mortality rates for the five intervals were 0.03, 0.08, 0.03, 0.03 and 0.04 lambs per potential lamb at scanning, respectively. Lamb mortality was highest at birth, with lower survival rate of triplet-born lambs compared with single- and twin-born lambs (0.82{\textpm}0.006 vs 0.93{\textpm}0.004 and 0.93{\textpm}0.002 lambs per potential lamb respectively; P<0.001). The results indicated when, and to what extent, lamb losses occurred in the field between pregnancy scanning and weaning, and the importance of applying appropriate ewe/lamb feeding and management policies to minimise lamb mortality rates. }, issn = {1176-5283}, author = {Nicoll GB and Dodds KG and Alderton MJ} } @conference {41065, title = {Fleece production patterns in Romney ewes: Effects of photoperiod, pregnancy and lactation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {30-33}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Twenty one Romney ewes were housed indoors for 12 months from February to determine the effect of season, pregnancy and lactation on wool growth. Ten ewes were naturally mated in April to lamb in September. The ewes were fed to maintain constant maternal body weight and a midside patch harvested monthly to determine clean fleece growth rates. An effect of pregnancy on individual fibre length growth rate, determined by autoradiography, occurred as early as 21-35 days after joining. During the second month of gestation, fleece production and mean fibre diameter fell below that of non-pregnant ewes and continued to diverge until parturition. Wool production rose in the non-pregnant group from August, but did not increase in lambing ewes until after parturition. These data suggest that pregnancy is associated with an early hormonally-mediated depression in follicle output superimposed on the decline associated with winter photoperiod. }, issn = {1176-5283}, author = {Pearson AJ and Kendall PE and Ashby MG and Wildermoth JE} } @conference {41058, title = {The future for the N.Z. Society of Animal Production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {1-5}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Genetics is the study of inheritance, and animal breeding is the application of knowledge in genetics to achieve improvement. In the context of animal breeding, a systematic framework (Harris et al., 1984) is typically employed to design improved breeding programmes. The steps involved in this systematic framework include the following. 1.Define the goal of the business. 2. Identify the list of traits that influence the goal. 3.Determine the relative (economic) importance of the traits in the list. 4.Measure those characteristics that allow individuals to be ranked then selected (or culled) in terms of their contribution to progress towards the goal. 5.Make preferential use of superior individuals as parents of the next generation }, issn = {1176-5283}, author = {Garrick DJ} } @conference {41060, title = {Genetic effects in GrowBulk sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {14-16}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {GrowBulk sheep are a strain of long-wool type sheep growing high bulk wool developed by introgressing high-bulk genes from Texel and Dorset rams into Romney ewes. Progeny selection was planned to minimise decreases in clean fleece weight. Rams have been released to four multiplier flocks. Genetic effects were evaluated in the nucleus and multiplier flocks using a restricted maximum likelihood animal model. Heritability estimates were 0.46{\textpm}0.05 for bulk and 0.30{\textpm}0.05 for clean fleece weight with a genetic correlation of -0.48{\textpm}0.09. The crossbred genotypes represented in the nucleus flock showed a range in average breeding merit for bulk of 27 to 31 cm{\textthreesuperior}/g, their weighted mean genetic superiority over contemporaneous Romneys being 5.3 cm{\textthreesuperior} /g. The first crop of commercial progeny by rams from this flock showed an average genetic superiority in bulk over their dams of approximately 4 cm{\textthreesuperior}/g. Genetic trends indicate that selection has been able to maintain the bulk advantage of the crossbreds while at the same time improving their fleece weight. }, issn = {1176-5283}, author = {Clarke JN and Sumner RMW and Cullen NG} } @conference {41097, title = {Genetic parameter estimates for lamb survival in Romney sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {121-124}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Lamb survival is a trait of economic importance in sheep production. Most lamb losses occur within 1 to 2 days of birth. Losses may be attributed to the lamb and to the behaviour of the dam. Maternal effects are environmental for the offspring but are genetic for the dam. ANIMALPLAN has separately evaluated individual and maternal attributes. Difficulties arise to genetically evaluate animals for survival because this trait has a binomial distribution whereas most analytical procedures assume normality. The objective of this study was to estimate heritabilities and genetic correlations for direct and maternal genetic effects on two underlying scales (probit and logit) for lamb survival in order to implement a new procedure of genetic evaluation. Variance components were obtained by Restricted Maximum Likelihood (REML) procedures after logit or probit transformation of the data with a linear mixed model using records from 25,874 lambs born over the period 1989 to 1995 in a prolific Romney flock. The lambs were the progeny of 218 sires and 6,771 dams. The model included fixed effects of sex, year, litter size at birth and age of dam and the random effects for direct genetic, maternal genetic and maternal environmental influences. Lambing and survival percentages were 178\% and 87\%, respectively. The estimates of heritability on the logit scale were 0.01, 0.03 and 0.04 for direct, maternal and total genetic effects, respectively. The proportion of total variance explained by maternal environmental influences was 0.09. The estimated genetic correlation between direct and maternal genetic effects was - 0.26. Similar estimates were obtained on the probit scale. Estimates will be lower for the observed scale. These results indicate a greater opportunity for improving survival by manipulating the environment rather than by selection. However survival analysis is an important component of quality assurance in a genetic improvement scheme. }, issn = {1176-5283}, author = {Lopez-Villalobos N and Garrick DJ} } @conference {41096, title = {Genetic progress in a Romney Group Breeding Scheme}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {117-120}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The Auckland Romney Development Group was established in 1968 and its aims continue to be to test and select rams for Group Members, and to breed rams for sale under conditions relevant to farming in the greater Auckland district. Breeding objectives include increased litter size (NLB), weaning weight (WWT), yearling live weight (YLW), yearling greasy fleece weight (YFW), and also increased facial eczema (FE) tolerance. Each year until 1993, members received selected nucleus-bred 15-month rams for use at home, and the next cut of nucleus rams and some elite homebred rams were offered as breeding stock for sale. From 1993, restricted maximum likelihood methods were introduced to calculate breeding values, and across-age ram selection was applied. At the same time, the nucleus ewes were re-distributed across all Members{\textquoteleft} flocks, and between-flock and between-year genetic links were maintained by movement of sires for mating. Estimates of total genetic progress by birth-year (obtaining data from Animalplan files, which were only available from 1986) were: WWT (1986-97) 1.83{\textpm}0.17 kg (7.8\% of the mean), YLW 2.76{\textpm}0.24 kg (6.4\%), YFW 0.23{\textpm}0.01 kg (7.3\%) and NLB (1986-95) 0.029{\textpm}0.015 lambs (1.8\%), and all flocks have contributed to the long-term genetic changes. Annual genetic trends over the period were approximately linear, except for YLW which appeared to show an increasing response rate. This is probably related to the extensive progeny testing carried out since 1994 to study sire families which appear to be elite for YLW, using progeny-test matings of rams to outside tester ewes. Segregation tests for a possible major gene have been carried out. Some evidence of bimodal distributions for YLW within sire was found, with a gene whose effect was +9\% of the mean, in heterozygotes. Since 1993, secondary selection decisions based on FE have been complicated by across-flock selection, but genetic progress for this trait appears to be linear, with a heritability estimate for log (gamma glutamyltransferase; GGT) of 0.34{\textpm}0.09. Over the birth years 1981-1997 there was genetic change in GGT by a factor of 0.71 (29\% improvement), compared with a factor of 0.30 (70\% improvement) over the same time period in the single-trait FE selection lines at Ruakura (Resistant versus Control lines). }, issn = {1176-5283}, author = {Morris CA and Amyes NC and Hickey SM} } @conference {41095, title = {A genetic test to identify carriers of the ovine Inverdale fecundity gene}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {114-116}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The Inverdale high fecundity gene (FecXI ) is carried on the sheep X-chromosome. This provides a convenient means of producing prolific single copy carrier ewes because all daughters of a carrier ram will inherit the gene. A single copy of the gene increases litter size by about 0.6 lambs per ewe lambing. However, ewes homozygous for the gene are infertile. Production of elite rams that carry the gene requires the ability to distinguish between non-carrier and single copy carrier animals. Three DNA markers flanking the gene in a 10 cM (centiMorgan) region have been used to develop a genetic test that can identify single and double copy carriers in most cases. The test relies on detecting inheritance of the Inverdale region of the X-chromosome in offspring of known carriers. Validity of the genetic test has been confirmed by progeny testing of rams and laparoscopy of ewes. The test has recently been adapted to DNA obtained from a few plucked wool follicles. }, issn = {1176-5283}, author = {Galloway SM and Cambridge LM and Henry HM and Van Stijn TC and Davis GH} } @conference {41132, title = {Has Rabbit Haemorrhagic Disease worked in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {245-249}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {This paper reports on some results of a field study of Rabbit Haemorrhagic Disease (RHD) since its illegal release in New Zealand in August 1997. The presence of fresh carcasses and seropositive rabbits of different ages were used to indicate the presence of RHD in rabbit populations, and changes in rabbit densities were used to infer its efficacy.Serological evidence from two Otago study sites where rabbits were sampled before and five times after the initial epidemic shows that (a) biociding left more seropositive, and so immunised, adult survivors than were left after a natural epidemic; thus natural epidemics are best if they persist, (b) the proportion of seropositive rabbits in cross-sectional samples declined over the 6 months after the initial epidemic, and (c) a second epidemic of RHD broke out naturally at both sites in September 1998. At 36 study sites around New Zealand, the initial 1997 epidemics caused declines in rabbit densities averaging 32{\textpm}23 \% (95\% S.E.) in the North Island and 56{\textpm}23\% in the South Island. However, success was not universal and rabbits increased at a few sites.Causes of failure at some sites have been attributed to poor-quality biociding where rabbits were vaccinated rather than infected.Variable kills were also seen in natural epidemics at sites where the initial rabbit densities were less than c. 25 rabbits seen /spotlight km, while consistently high kills were evident at intial densities above this threshold. Overall, rabbit numbers increased at most sites measured between winter 1998 and early 1999, despite second epidemics being confirmed at some of these sites. The optimal strategy to manage rabbits as pests of pastoral production in New Zealand cannot be determined because we cannot yet predict the behaviour of RHD, and we have insufficient information on the relationships between rabbit densities and their impacts on production, although a single unreplicated trial we did in Otago showed that the reduction in rabbit numbers due to RHD reduced the grazing impacts of rabbits by 77\%. Therefore, in the absence of any robust measure of benefits we cannot judge how much it is worth spending on conventional control. These information gaps are hindered by the old paradigm of rabbit control – “knock them down and hold them down”. If this strategy was ever the best for a boom-bust pest, it is certainly not so now that a biological control agent is at least partially successful and persistent. }, issn = {1176-5283}, author = {Parkes J and Norbury G and Heyward R} } @conference {41061, title = {Hogget wool traits of sheep breeds being used for crossbreeding with strong wool breeds - preliminary estimates from research studies}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {17-18}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Average fleece weight and wool quality characteristics for pure breeds were calculated from comparisons of pure breeds and crossbreeds with strong wool sheep in fifteen studies. The results for each breed reflect the sample of the breed selected for the studies, after removal of environment effects. Compared to the average Romney, fibre diameter was markedly lower in Merino (59\% of Romney, P<0.001) and Finn (72\%, P<0.001) but was not significantly different in Texel, Poll Dorset and East Friesian sheep. Staple lengths of other breeds were 53 to 77\% (P<0.05) of Romney values. Wool bulk was greater in Texel and Poll Dorset (both 49\%, P<0.001), and Merino (32\%, P<0.01). To provide a better basis for predicting effects of crossbreeding in breeding ewe flocks, more information is needed from the East Friesian breed. Also the observations need to be extended to adult ewes and need to be obtained from wider samples of the breeds and sheep farming environments, and account needs to be taken of heterosis and other effects. }, issn = {1176-5283}, author = {Bray AR} } @conference {41099, title = {The importance of date of birth records in genetic evaluation of deer}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {129-130}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {This paper addresses one particular difficulty associated with performance recording and genetic evaluation of deer, that is, the problem of recording pedigrees. A deterministic simulation was carried out using parameters based on deer populations where birthday has been recorded. For weaning weight, failure to record birth date resulted in reductions by 29\% and 19\% in selection accuracy, with selection on the records from the individual or from 20 progeny respectively. Corresponding reductions for yearling weight were 11\% and 5\% respectively. It was concluded that while genetic progress in deer will be compromised by lack of date of birth records, selection for growth traits can still be effective.}, issn = {1176-5283}, author = {Amer P and Garrick D and Nicoll G} } @conference {41076, title = {Improving lamb birth weight through mid-to-late-pregnancy shearing: a review of recent studies}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {70-72}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A series of five experiments have been conducted at Massey University to determine whether mid- to late-pregnancy shearing of ewes might provide an opportunity to increase lamb birthweights and enhance survival, particularly of multiple-born lambs, under New Zealand{\textquoteleft}s pastoral conditions. Although birthweight responses were seen in most studies, they were not consistent with respect to the magnitude of the response or its occurrence in singles vs twins. However, when comparison was made across studies there was a strongly negative relationship between the size of the response and the birthweights of control lambs (those from unshorn ewes). We conclude that responses to mid- to late-pregnancy shearing are likely to be greatest when fetal growth in unshorn ewes is limited by maternal constraint. }, issn = {1176-5283}, author = {Kenyon PR and Morris ST and Revell DK and McCutcheon SN} } @conference {41104, title = {Incidence of high pH in venison: Implications for quality}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {145-147}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Muscle ultimate pH (pHu) is known to influence eating quality, functional properties and safety in beef, lamb and pork. The extent to which muscle pH affects tenderness and the extent to which it can be {\textquoteleft}aged{\textquoteleft} out is different for lamb compared to beef and two studies have been carried out with venison in order to determine the implications for venison tenderness. Longissimus thoracis et lumborum (striploin) muscles from nine carcasses which went prematurely into rigor ({\textquoteleft}stiff{\textquoteleft} carcasses) had higher mean pH than muscles from nine control carcasses (5.93 vs 5.61, SED = 0.091 at 2 days postmortem (PM); 5.83 vs 5.56, SED = 0.100 at 7 days PM; 5.81 vs 5.54, SED = 0.096 at 21 days PM). A typical quadratic relationship was observed between tenderness and pH which explained non-significant differences in tenderness between the stiff and control muscles. The tenderness-pH relationship for venison striploins assessed at 2 days after slaughter was typical of that reported for unaged beef and lamb in that muscles with pH in the range of 5.8-6.2 were tougher (P< 0.05) than normal (5.5-5.7) and high (>6.2) pH muscles. The tenderness profile change after 7 and 21 days chilled storage at 4{\textdegree}C was similar to that reported for lamb in that all of the striploin samples tenderised to an acceptable level. Ten intermediate pH (5.8-6.2) biceps femoris (BF) muscles were tougher (P< 0.05) than ten normal pH (5.5-5.7) muscles at all times with chilled storage at 0{\textdegree}C for up to 6 weeks. The intermediate pH muscles that were frozen then thawed prior to assessment were significantly more tender than the chilled intermediate pH muscles, but still tended to be tougher than the normal pH muscles. Both the chilled and frozen intermediate pH muscles were significantly more variable in tenderness than the normal pH BFs. }, issn = {1176-5283}, author = {Stevenson-Barry JM and Carseldine WJ and Duncan SJ and Littlejohn RP} } @conference {41116, title = {Increasing milksolids production with supplementary feeds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {188-191}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Four farmlets were established at a stocking rate of 4.41 Friesian cows per hectare to compare rolled maize grain, maize silage and a nutritionally balanced ration as supplementary feeds for grazing dairy cows, for three complete seasons. Supplements were offered whenever it was estimated the herds were eating less than 15 kg DM/cow/day or were leaving a post-grazing residual herbage mass of less than 1800 kg DM/ha. Offering 1.3 to 1.5t DM/cow/year of supplement increased net herbage accumulation from 18.3 to 19.2 t DM/ha, however, this did not result in higher annual herbage intake. The use of rolled maize grain, maize silage, and balanced ration supplements increased production from 1188 kg milksolids (MS)/ha to 1763, 1602, and 1769 ({\textpm}69.6) kg MS/ha/year, with responses of 98, 77, and 99 g MS/kg DM, respectively. The magnitude of the response to the supplementary feed was directly proportional to the increase in metabolisable energy supplied by the supplement. Full lactation responses to supplementary feeds were two fold greater than those measured in short term feeding trials. Responses of 7.5g MS/MJME can be expected over the complete lactation when supplements are offered to dairy cows grazing restricted pasture. }, issn = {1176-5283}, author = {Penno JW and McGrath JM and MacDonald KA and Coulter M and Lancaster JAS} } @conference {41073, title = {Lack of effect of short term chromium supplementation in lactating Jersey cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {58-61}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The responses of dairy cattle to chromium (Cr) supplementation reported in the literature suggest that it has the potential to reduce the incidence of both mastitis and ketosis. The effect of Cr supplementation of pasture fed dairy cows in early lactation was studied. Ten lactating Jersey cows fitted with rumen fistula were infused with either Cr-yeast (n=4), casein (n=3) or buffer only (controls; n=3) directly into the abomasum. All cows were subjected to a hyperinsulinaemic euglycaemic clamp. Preliminary results show that there was no effect of Cr supplementation on milk yield, cortisol and b-hydroxy butyrate concentrations and somatic cell counts. }, issn = {1176-5283}, author = {Back PJ and Lee J and MacKenzie DDS and Davis SR and Harris PM} } @conference {41137, title = {Marker-assisted Selection for Meat Quality and the Ovine Calpastatin Gene}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {266-268}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The calpain-calpastatin system (CCS) comprises a family of calcium-dependent neutral proteases, the calpains, and calpastatin, a specific inhibitor of the calpains that regulates their activity in vivo. The CCS is found in most animal tissues and influences many important processes including muscle development and degeneration, meat tenderisation postmortem, cataract formation and fertility. The calpains have been shown to play the major role in postmortem tenderisation in beef, lamb and pork by degrading specific muscle structural proteins. The level of calpastatin immediately postmortem appears critical in determining the ultimate tenderness of aging muscles. Tenderness has been shown in consumer surveys and tasting panel tests to be the most important characteristic determining the overall eating quality of meat. In using a molecular genetic approach to studying meat quality in sheep we have chosen the ovine calpastatin gene (CAST) as a candidate gene for meat quality. We have described a three allele system of polymorphic variants (CAST a, b and c) in a region of the ovine CAST. Since 1995 we have carried out slaughter trials on small groups of Dorset Down hoggets and Dorset Down x Coopworth lambs to ascertain any association between meat quality traits and the molecular markers in CAST. Sheep with the genotypes of CAST aa, ab and ac were compared. These trials indicate an association of the CAST genotype ac with increased liveweight gain (+12-17\%,p >0.05), increased age-corrected carcass weight (+15-18\%, p>0.05), but also increased longissimus dorsi shear force (+4-12\%, nonsignificant) compared to sheep with the CAST genotype aa. }, issn = {1176-5283}, author = {Palmer BR and Morton JD and Roberts N and Ilian MA and Bickerstaffe R} } @conference {41127, title = {A methodology for dealing with uncertain outcomes when applying embryo technologies}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {226-228}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {High variability in number of embryos collected per donor has implications when programming recipients for {\textquoteleft}fresh{\textquoteleft} embryo transfer because decisions on the number of recipients required need to be made prior to collecting embryos. This paper describes a methodology for dealing with these uncertainties. The distribution of number of transferable quality embryos per donor was determined and conformed to a Poisson distribution. The distribution of the proportion of recipients that are suitable for transfer was assumed to be binomial. The model determined recipient numbers under 4 contrasting risk scenarios, and compared these with a simple arithmetic approach. The simple arithmetic approach is likely to expose programmes to high levels of risk. The proposed methodology enables practitioners to programme the number of recipients that is consistent with any level of risk they are prepared to take in having surplus embryos or recipients. The model could be extended to provide economic or utility maximisation endpoints. }, issn = {1176-5283}, author = {McMillan WH and Vivanco HW} } @conference {41122, title = {Milk production and production worth of anoestrous dairy cows compared with their cycling herd mates}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {208-210}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The primary aim of this study was to determine whether the milk production and production worth (PW) of anoestrous (AA) cows differed from that of their cycling (CYC) herd mates. In addition, a pilot survey was carried out to examine between herd factors, which may influence the percentage of cows diagnosed anoestrous. Individual production records were collated from 7786 cows in 26 herds, in which AA cows were identified following veterinary examination seven days before the planned start of mating. Milk production and PW did not differ between AA and CYC cows, after adjusting for herd, age and days in milk (P>0.05). The percentage of cows diagnosed AA varied from 13.4\% to 51.5\% among herds. Completed questionnaires were obtained from 19 herd owners regarding management factors in these herds. Stocking rates were higher in herds with a low percentage of anoestrous cows (<30\%AA) compared with those with a high percentage (>=30\%AA; p=0.05), but level of supplementary feeding was higher in herds with a low level of anoestrous (p=0.01). It is concluded that milk production and PW do not differ between AA and CYC cows. Nutritional supplementation after calving may influence the percentage of a herd still anoestrus before the start of mating. }, issn = {1176-5283}, author = {Rhodes FM and Morgan S} } @conference {41135, title = {Milk production from perennial ryegrass pastures containing different levels of endophyte}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {258-262}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {These experiments aimed to compare milk production in spring and autumn from perennial ryegrass pastures containing either low (L) (<10\%) or high (H) levels of endophyte infection at two pasture allowances. In October 1997 milk yield was higher (P<0.05) from L compared with H endophyte (15.1 v 14.4 kg/cow/day), similarly for fat yield (0.95 v 0.9 kg/cow/day), and milksolids (MS) (1.53 v 1.46 kg/cow/day), but not protein yield. In October 1998 there was no effect of endophyte level on milk, fat, protein and MS yield. In March 1998 milk yield was higher (P<0.001) from H compared to L endophyte (8.5 v 7.4 kg/cow/day), similarly for fat yield (0.53 v 0.48 kg/cow/day), protein yield (0.35 v 0.34 kg/cow/day) and MS yield (0.89 v 0.81 kg/cow/day). No carryover effects were recorded on milk yield or composition in any period.}, issn = {1176-5283}, author = {Clark DA and Thom ER and Waugh CD and Burggraaf VT} } @conference {41115, title = {Milk production response to replacement of carbohydrate with lipid and the addition of ruminally protected protein}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {184-187}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Cows grazing a restricted pasture allowance of 25 kg DM/cow/day during November (75 days in milk) were offered five supplementary feeds in a factorial experiment. The supplements were isoenergenic supplying an additional 68 MJME/cow/day but varied in whether the energy source was lipid or carbhydrate (rapeseed vs maize), crushed or whole rapeseed (cruide protein (CP), 20.6\%), or with and without ruminally protected protein (formaldehyde treated sunflower meal, 37.8\% CP). The CP contents of the pasture and the maize supplement were 14.7\% and 9\% respectively giving an average CP of the feed consumed of 13\%. Cows on the control treatment supplemented with maize grain produced means of 10.5 l/d of milk, 0.61 kg/d fat, 0.43 kg/d of protein and 1.03 kg/d of milksolids. Partial replacement of maize with 20 MJME/cow/day of rapeseed (CP of supplement, 11.8\%) increased daily milk (9.3\%), fat (8.6\%), protein (4.4\%) and milksolids (6.9\%) yields. Crushed rapeseed resulted in twice the yield increase as whole rapeseed. Additional replacement of maize with 13 MJME/cow/day of ruminally protected protein (CPO of supplement 18\%) resulted in further increases of 15.9\%, 16\%, 17.4\% and 16.8\% for milk, fat, protein and milksolids respectively. The response to ruminally protected protein was greater when incorporated with maize/crushed rapeseed than maize/whole rapeseed. Crushed rapeseed depressed fat and protein content in milk. Other supplements had no effect on fat, protein or lactose contents. Replacement of maize with crushed rapeseed and ruminally protected protein increased yields of milk (36.1\%), fat (32.9\%), protein (23.5\%) and milksolids (31.8\%) compared to maize alone. For cows 75 days in milk the results demonstrated that a dairy ration comprising 13-14\% CP provided insufficient protein to sustain full milk production. }, issn = {1176-5283}, author = {Thomson NA} } @conference {41098, title = {Milking performance of East Friesian Poll Dorset cross ewe hoggets}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {125-128}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The milking performance of East Friesian Poll Dorset cross and Poll Dorset hoggets in a commercial milking system was studied at Flock House Agricultural Centre. Hoggets were milked twice daily from 2-4 days post-lambing on a 30 bale rotary platform for about 102 days. Live weight of the Poll Dorset and East Friesian cross hoggets were similar (P>0.05), both groups increased in weight from 51.5 {\textpm} 0.7 to 61.8 {\textpm} 0.8 kg over the trial period. Mean daily milk yield of the East Friesian cross hoggets was significantly higher (P<0.01) than for the Poll Dorset hoggets, 1.13 {\textpm} 0.06 and 0.87 {\textpm} 0.08 l/ewe/day, respectively. Milk production of the East Friesian cross hoggets over the lactation period was 30\% higher in milk volume (113.1 {\textpm} 6.0 versus 86.8 {\textpm} 7.9 l/ewe) but had a lower milk solids content (18.19 {\textpm} 0.06 versus 18.48 {\textpm} 0.07 \%) resulting in a 25\% higher yield of milk solids (204 {\textpm} 3 versus 164 {\textpm} 4 g/ewe/ day) than Poll Dorset hoggets.}, issn = {1176-5283}, author = {Newman S-AN and Stieffel W} } @conference {41130, title = {Monitoring oestrus and ovulation in brushtail possums}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {236-238}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The time of ovulation following removal of pouch young (RPY) was determined in 240 possums by repeated laparoscopic observation of the ovaries, and in a subset of these animals (n=20) also from changes in vaginal mucus. In a separate experiment (n=18), the time of oestrus was estimated from an influx of epithelial cells and leucocytes in urine, and confirmed by mating and hormonal data. A preovulatory follicle was observed at laparoscopy in all animals that ovulated (n=138), but not in any that did not (n=102). An influx of neutrophils in vaginal mucus occurred in 12/20 possums, including 4 that failed to ovulate. An increase in epithelial cells in urine was observed in 9/12 possums that exhibited an LH surge. However, this change occurred after the time of the preovulatory LH surge in 6 of those animals and peak cell numbers varied widely between all animals. These studies confirm that although changes in the cell content of mucus and urine can retrospectively define stage of the oestrous cycle, they are of little value for predicting impending oestrus, the LH surge or ovulation}, issn = {1176-5283}, author = {McLeod BJ and Thompson EG and Crawford JL and Mahoney PM and Eckery D} } @conference {41141, title = {Mouse 3T3-L1 Fibroblast Cells as a Bioassay For Serum-Borne Adipogenic Factors}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {279-281}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {This study of the development of adipose tissue in sheep set out to investigate whether culture medium containing serum from Coopworth lean and fat selection lines had differential effects on proliferation and differentiation of mouse 3T3-L1 preadipocytes. Using fetal calf serum (FCS) as a positive control, the effects of serum from lean and fat lines of sheep and from goat and horse were compared by analysing total cell numbers, and protein and triglyceride (TG) levels per unit DNA in the mouse cell cultures. Differentiation was induced in all serum treatments. Mean cell numbers in cultures up to 13 days after differentiation were higher for sheep serum than for the other species (P<0.001). There was no significant difference (P>0.05) in protein content between FCS and serum from lean and fat sheep lines. Mean TG levels were significantly higher (P<0.001) for FCS than for the lean and fat selection lines, which did not differ significantly from each other (P>0.05). Significant differences in either proliferation or differentiation were not detected between the fat and lean sheep. }, issn = {1176-5283}, author = {Veenvliet BA and Littlejohn RP and Suttie JM and Broad TE} } @conference {41093, title = {Nutritional effects, in early pregnancy, on lamb production of Finnish Landrace x Romney ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {108-110}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {This study tested the hypothesis that in high fertility ewes, low nutrition in early to mid pregnancy could affect placental development in turn affecting foetal development, lamb birth weight and lamb survival. In 1997, 600 Finn x Romney ewes were randomised to 1 of 5 herbage allowance treatments applied over day 20 to 70 of pregnancy. Over the treatment period, mean herbage intake ranged from 0.69 to 2.04 kg DM/ewe/day resulting in ewe live weight changes of –36 to +60 g/ewe/day respectively (p<0.001). The result was a consistent but non-significant trend in birth weight with the lowest allowance ewes having single and twin lamb birth weights of 5.2 and 4.3 (SED 0.2) kg respectively. Corresponding birth weights for lambs from the highest allowance ewes were 5.3 and 4.4 kg. Lambing rate and lamb survival were not affected. In 1998, 4 nutrition treatments were applied from day 7 to 70 of pregnancy to 650 ewes randomised from either of 2 reviously generated mating weight groups. These treatments gave live weight changes of –84 to +35 g/ewe/day (p<0.001) from average herbage intakes of 0.70 to 1.96 kg DM/ewe/day. Birth weight of the single lambs (trial average 5.0 kg; SED 0.1) was not affected. However, twin lambs born from ewes from the lowest herbage allowance treatment were 0.35 kg lighter than those from the other treatments (p<0.01). Similarly, lambs born per ewes mated and lambs weaned per ewes present at lambing were also affected (p<0.05). We conclude that, in fecund ewes, nutrition in early pregnancy can affect twin lamb birth weight and lambing rate but only where the ewes are losing weight at more than 40 g/ewe/day or lose more than 4 kg from mating to mid-pregnancy.}, issn = {1176-5283}, author = {Smeaton DC and Webby RW and Tarbotton I} } @conference {41075, title = {Pasture digestion in response to changes in ruminal pH}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {66-69}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Four continuous culture fermenters were used to determine the ruminal pH required for the optimal digestion of pasture. Spring pasture was fermented at four controlled levels of ruminal pH (5.4, 5.8, 6.2 and 6.6) according to a 4x4 Latin square design. Decreasing pH from 6.6 to 5.4 reduced dry matter digestion by 14\%, neutral detergent fibre digestion by 11\%, total non-structural carbohydrate digestion by 5\% and microbial nitrogen flow by 18\%. A quadratic relationship was observed between ruminal pH and the true ruminal digestibility of dry matter (R{\texttwosuperior}=0.94, SE=2.06) and microbial nitrogen flow (R{\texttwosuperior}=0.66, SE=0.05). The ruminal digestibility of pasture dry matter was optimised at pH 6.35, and synthesis of microbial protein was optimised at pH 6.13. This experiment indicated that digestion was largely insensitive to pH across a broad range of pH (5.8 to 6.6), but that a large reduction in digestion occurred when mean pH was less than 5.8. }, issn = {1176-5283}, author = {de Veth MJ and Kolver ES} } @conference {41134, title = {Performance of dairy cows grazing pastures with or without ergovaline and lolitrem B in Northland.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {254-257}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Ergovaline and lolitrem B are alkaloids produced by Neotyphodium endophytes in ryegrass. These toxins are associated with poor animal performance in many situations but influences on milk production by dairy cows had not been determined in NZ except for short-term trials. An on-farm trial was set-up at Te Hana to measure milk production responses in 2 groups of 16 cows which were maintained on a) ryegrass-based pastures which contained wild-type endophytes which produced ergovaline and lolitrem B [+Ev] or on b) ryegrass pastures that were either free of endophyte or contained a novel endophyte which did not produce ergovaline or lolitrem B [-Ev]. The trial ran from October 1997 til mid-April 1998 and milk production was recorded for each cow at each milking for 10 consecutive days per month culminating in a herd test. There was no difference in milk production in October and November, but a difference of 25\% developed in December in favour of the -Ev group and substantial differences in production were maintained until the trial was terminated. Effects of ergovaline on cow performance are discussed in relation to environmental and behavioural factors.}, issn = {1176-5283}, author = {Keogh RG and Blackwell M and Shepherd P} } @conference {41129, title = {The prevalence of Wobbly Possum disease in a bush/farmland environment}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {233-235}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The prevalence of Wobbly Possum disease was monitored in wild-caught possums captured at 16 different sites. All animals were assessed for clinical signs of Wobbly Possum Syndrome from the time of their capture. Any that displayed symptoms were euthanased immediately and submitted for post mortem examination to confirm disease status. Of the 887 possums screened, 39 (4.4\%) were infected with the Wobbly Possum virus. These had been trapped at 10 of the 16 sites (prevalence 0\% to 23.3\%). There were no significant differences in the proportion of infected animals among sites. The interval from time of capture to diagnosis ranged from 7 to 21 days. The presence of Wobbly Possum infection was not related to geographical location, sex of the animal or liveweight at the time of capture. This study suggests that both the natural prevalence of Wobbly Possum Syndrome, and the rates of cross-infection within a site are low. }, issn = {1176-5283}, author = {Thompson EG and McLeod BJ} } @conference {41143, title = {The relationship between beef ultimate pH, breed of cattle, muscle glycogen and enzyme levels and animal behaviour}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {287-290}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {To determine the incidence of high ultimate pH (pHu) across farms 967 cattle were involved in a survey which showed 3\% of Angus, 21\% of Simmental cross and 60\% of the Friesians steers had an pHu above the acceptable maximum of 5.8. In further work, muscle (longissimus dorsi) biopsies samples were taken from 60 two-year-old Angus, Simmental cross and Friesian steers (n = 20 per breed) in late November and assayed for glycogen concentration and enzyme concentrations that indicated muscle fibre type. Behaviour measurements were made on all animals before slaughter. Individual measurements of carcass characteristics were made 22-24 hours after slaughter, including carcass weight, pHu, meat colour score, and fat depth (GR). Only one carcass had a pHu above 5.8 and there was no pHu difference between breeds (5.53, 5.55, and 5.58 for Angus, Simmental cross, and Friesian, respectively). There was no difference between breeds in the glycogen concentration in the muscle, although there were differences in enzyme concentrations that suggested differences between breeds in the proportion of the three muscle fibre types. Flight distance were small (4-7 m) but longer for Friesian than Simmental cross steers. There were no relationships between meat pHu and flight distance, glycogen concentration or muscle enzyme concentrations. Breed did not appear to effect pHu or muscle glycogen concentration. }, issn = {1176-5283}, author = {Webby RW and Fisher AD and Lambert MG and Turner P} } @conference {41068, title = {Relationship between wool sulphur concentration and wool characteristics}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {43-45}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {It is well established that naturally occurring wool sulphur concentration is lower in high wool-producing sheep, however little is known of the relationship between wool sulphur concentration and wool fibre characteristics. Mid-side wool samples were collected from ewe hoggets differing in lamb wool sulphur concentration. Wool from hoggets, which had lower wool sulphur concentrations as lambs, had longer staple lengths, were higher yielding and had lower loose wool bulk values. There was no relationship between wool sulphur concentration and mean fibre diameter or colour. An increase in length should have a positive effect on the price of wool, especially for second shear crossbred wools. At present the price premium for bulk is poorly defined, but is unlikely to have a significant impact on the value of these wools. These findings suggest that selecting animals for low lamb wool sulphur concentration will, if anything, positively affect the per kilo price of wool produced. }, issn = {1176-5283}, author = {Kenyon PR and Sherlock RG and Lee J and Blair HT} } @conference {41102, title = {The relationship of meat quality to age at slaughter and indicators of animal age in red deer stags and hinds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {137-139}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Groups of five stags and hinds were slaughtered in late summer (February/March) to examine the effects of age and sex of animal on meat quality. For both sexes the groups were the following ages: 1, 2, 3 and 5 years. In the 2 year old age group for stags there were three weight groups and additionally there was one group of 8 year old stags and one of 13 year old hinds. The group mean hot carcass weight (HCW) range was 51 to 119 kg for stags and 43 to 57 kg for hinds. The HCW{\textquoteleft}s tended to increase with age but the {\textquoteleft}light{\textquoteleft} and {\textquoteleft}medium{\textquoteleft} weight 2 year old males had lower (P< 0.05) mean HCW than all of the other male groups including the 1 year olds. The GR increase with age was much greater in stags than in hinds; 80\% of the stags 3 years and older and 27\% of the hinds 3 years and older graded over-fat. In both hinds and stags, GR was strongly related to carcass weight. Meat from 5 and 8 year old stags was much tougher (P< 0.05) than that from all other groups. Of all the attributes measured as possible indicators of animal age, only carcass neck a* value (redness) was able to accurately discriminate ages of animal and provided the best categorisation of animals into tenderness classes. }, issn = {1176-5283}, author = {Stevenson-Barry JM and Drew KR and Duncan SJ and Littlejohn RP} } @conference {41069, title = {Relationships of fleece and fibre traits with unscourable yellow discolouration in a survey of strong wool sheep flocks}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {46-48}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Wool samples were collected over two years from sixty two lines of sheep in flocks spread around New Zealand, to provide wool from a variety of strong wool genotypes and farming environments. Within-line relationships of unscourable discolouration with objective measured and subjectively assessed fleece and fibre traits were determined by correlation and regression analyses. The trait most highly correlated with the CIE measurement of yellow discolouration (Y-Z) within lines was Z (R2 = 0.58). CIE and Y values were more weakly correlated (R2 = 0.19 and 0.18, respectively) as was the maximum visibly assessed yellow score, and staple definition accounted for 33\% of the variation. Variation in other fleece and fibre traits within flocks was associated with Y-Z. The reasons why the scoured wool of some sheep in a flock show more discolouration than that of others were not found among the 38 traits examined in this project. }, issn = {1176-5283}, author = {Bray AR and Smith MC} } @conference {41120, title = {The Relevance of Applied Bio-Physical Research: A Case Study into Beef Breeding Cow Twinning Technology}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {201-204}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Science funders need to know that their investment in technology will be relevant and useful. Pre-trial social research and the involvement of potential users in project management, enables scientists to ensure that these conditions are addressed. This paper examines the development of twinning technology for beef breeding cows as an example. Preliminary social research in 1995 showed that users wanted information about the technology and its interactions with sheep production and lamb finishing. They also wanted to know the labour requirements, and new skills needed for producing successful results. A systems trial examining these issues commenced at Whatawhata Research Centre later that year. A mentor group was initiated at the start of the trial with farmers, scientists, funders, and a vet included. This group was involved in trial management over the three-year period of the trial. The trial has shown that it may be profitable for farmers to produce twin calves and grow them out to 18 months of age or older, providing that they can manage calving. Twinning cows were shown to be complimentary to sheep breeding and lamb finishing. The role of the mentor group was evaluated in a survey of group members in 1997. The group was shown to be of high value to the individuals involved, and to the livestock industry, through providing greater opportunities for farmers and scientists to learn from each other. However, there was some concern that the mentor group process could increase the costs of carrying out research.}, issn = {1176-5283}, author = {Parminter T and Smeaton D} } @conference {41084, title = {The results and success factors of nine group farm monitoring programmes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {87-90}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Results from 9 farmer groups located in the upper North Island and operating over the period of 1988 to 1998 showed that group farm monitoring has facilitated changes in farm practice performance and income. The process in-volved groups of farmers with associated consultants, veterinarians and scientists; and the detailed monitoring of a central farm for 3 to 4 years. Changes made on the monitor farm incorporated the optimisation of the farm system and the adaptation and use of new sheep and beef cattle farming technologies. Increases in production ranged from 8 to 37\%; and increases in farm revenue from 13 to 31\%. Changes to stock policies that better aligned feed demand and supply, in-creased growth rates of young animals and greater efficiencies in breeding ewe and cow performance were common contributors to improved performances. The group farm monitoring process emphasised the value of gathering and effectively using farm and product information and provided a collective learning environment for farmers within a group context. Critical success factors that have emerged from a decade of work experience associated with group process are highlighted and discussed in the paper.}, issn = {1176-5283}, author = {Sheath GW and Webby RW and Keeling P and Thomson RD and Page CR and Burton GT} } @conference {41103, title = {A review of forage grazing systems to produce venison according to market signals}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {140-144}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Grazing systems are described for producing venison carcasses weighing 50-65 kg (92-120 kg liveweight) in the spring by one ear of age (30 November), using red and hybrid (0.25 elk: 0.75 red) deer stags. Grazing perennial ryegrass/white clover pasture at 10cm surface height during autumn, winter and spring resulted in 73\% of young stags attaining the desired slaughter target, but variation between years was large (range 25-100\%), with a contributing cause being variation between years in winter growth rate. When red clover and chicory were grazed during autumn and spring, with pasture grazing during winter, the proportion of young stags attaining the desired slaughter target was consistently increased to 90-100\% and mean carcass weights were increased by 11 \& 17\% respectively. Largest responses in deer growth to red clover (26\%) and chicory (47\%) over perennial ryegrass - based pastures were seen during autumn. Both voluntary feed intake (VFI) and digestibility of the diet selected were higher for deer grazing chicory and red clover than perennial ryegrass-based pasture, with the largest effects seen during summer and autumn, when perennial ryegrass was of lowest nutritive value. In indoor studies, both the rates of ruminal degradation and outflow of chicory were greater than for perennial ryegrass, with similar results found for red clover. It was concluded that the faster breakdown and clearance of red clover and chicory from the rumen than perennial ryegrass explained their higher digestibility and VFI by grazing deer. Management of red clover and chicory to increase persistence on commercial deer farms and grazing systems to support year round supply of venison in a branded market strategy are also discussed. For successful venison production by 12 months of age, target growth rates during winter of 100g/day for red deer and 150g/day for hybrids are suggested. }, issn = {1176-5283}, author = {Barry TN and Wilson PR and Kemp PD} } @conference {41144, title = {A review of recent findings on myostatin - a gene which controls muscle growth}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {291-293}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The enlarged muscles of certain breeds of cattle, such as the Belgian Blue, result from a marked increase in the number of normal sized muscle fibres. Originally insulin-like growth factors (IGFs) were implicated in this myofibre hyperplasia. Recently it has been reported that mice lacking a myostatin gene, a member of the TGFb super family, have enhanced skeletal muscle mass resulting from increased muscle fibre number and size. Mutations in this gene have been found in double muscled cattle, indicating that myostatin is an inhibitor of muscle growth. Myostatin is expressed early in gestation and then maintained to adulthood in certain muscles. Myostatin expression in bovine muscle is highest during gestation when muscle fibres are forming and some of the myogenic regulatory factors have elevated expression over the same period as myostatin. Myostatin and MyoD, myogenic regulatory factors expressed in muscle have been shown to differ between normal and hypertrophied muscle cattle breeds. This evidence strongly suggests that lack of functional myostatin is associated with an increase in fibre number which then results in a marked increase in potential muscle mass in double muscled cattle.}, issn = {1176-5283}, author = {Bass J and Oldham J and Sharma M and Kambadur R} } @conference {41119, title = {Sealing of the bovine teat canal after dry-off.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {198-200}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Closed teats have proven more resistant to dry period mastitis than open teats. Natural rate of keratin plug formation within closed and open teats, and consequences of bacterial colonisation of the teat canal, were examined using 67 low somatic cell count cows. Cows were dried off without antibiotic therapy and teats assessed for closure status at 5, 10, 15 and 20 d after drying off. Weight and bacteriological status of the keratin plug was determined by reaming teats with a sterile pre-weighed tapestry needle 7 d prior to drying off and on one occasion post drying off. Initially (d 5), keratin weight for all teats increased by 100\% compared to lactating teats (4.89 mg/qtr). Between d 10-20, keratin weight from open teats (29\% of teats) was 34-55\% less than for closed teats. Subclinical infections in the teat canal significantly reduced likelihood of teats closing after drying off. }, issn = {1176-5283}, author = {Lacy-Hulbert SJ and Williamson JH and Day AM and Woolford MW} } @conference {41126, title = {Seasonal changes in the protein content and composition of ram seminal plasma}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {223-225}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Seasonal changes in ram semen composition are accompanied by changes in fertility of frozen semen. These changes in fertility are not all easily explained simply in terms of the changes seen in sperm numbers per ejaculate. The possibility that changes in the composition of seminal plasma may be involved in the seasonal changes in ram fertility needs to be considered. An experiment that examined the protein content and composition of seminal plasma was conducted. Semen samples were collected from 10 rams ( 5 each from the BV -ve and BV +ve selection lines for early lambing) and the seminal plasma separated by centrifugation. Samples were collected with AV in the first week of each month for 12 months (after a 4-day period of abstinence). The protein concentration was determined and the samples were subjected to electrophoresis by SDS-PAGE using mini gels. Seminal plasma samples from all rams for each month were analysed on the same gel for each of the 12 months. In addition samples for all 12 months for each ram were also analysed on the same gel. The seasonal changes in seminal plasma protein profiles were recorded. There was a seasonal change in the total protein concentration of seminal plasma with higher levels (36.9 vs 23.0 mg/ml, P<0.001) observed during the breeding season (January to June). In the rams selected for out-of -season breeding (BV-ve) protein levels were also elevated in December and again in June and July. Several protein bands that were present in seminal plasma from all rams during the breeding season were absent from a number of rams during the non-breeding season (August to December). Their absence was confirmed on larger format 1D SDS-PAGE gels. The majority of these proteins fell between 20 and 70 kDa molecular weight. The absence of these proteins from seminal plasma coincides with the time of the year when we observed poor maintenance of motility in fresh semen and a reduction in the velocity of frozen/thawed sperm from semen collected from the same rams. Further work is required to identify and characterise these proteins and to elucidate their function and role in ram fertility.}, issn = {1176-5283}, author = {Smith JF and Parr J and Murray GR and McDonald RM and Lee RS-F} } @conference {41066, title = {Seasonal wool growth patterns and the follicle and fibre characteristics of New Zealand feral sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {34-38}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Wool follicle and fibre characteristics, and aspects of their seasonality were assessed in feral sheep from the Hokonui Hills (Merino origin), Campbell Island (Merino x long-wool breeds) and Raglan Peninsula (Romney). Live weight, fleece weight, staple length, crimp frequency, fibre diameter, fibre curvature, follicle density and secondary to primary follicle ratio differed between breeds, reflecting their breed origins. Mean clean fleece weights of the feral breed groups were approximately half that of their modern counterparts. Factors contributing to the low productivity were reduced staple length and follicle density, and a brief cessation of growth by some follicles during spring. The mean amplitude of rhythms in seasonal wool growth and fibre diameter increased with age, and appear to have converged to similar values, contrasting with their modern breed counterparts. }, issn = {1176-5283}, author = {Pearson AJ and Ashby MG and Sumner RMW and Nixon AJ} } @conference {41072, title = {Separate grazing as a breeding management strategy for anoestrous cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {55-57}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The aim of this study was to compare the rate of resumption of oestrous cycles and fertility to first insemination between anoestrous cows grazed separately (Split) or grazed in the main herd (Control) for 28 days and untreated or treated with progesterone (CIDR) and ODB from 7 days before the planned start of mating. Oestrus was detected in 54.7\%, 46.3\%, 93.5\% and 86.8\% of cows (Control, Split, CIDR and Split+CIDR, respectively) by 28 days after start of treatment (P<0.05). Compared to controls conception to first insemination was no different in Split and CIDR groups, but was reduced in the Split+CIDR group (P<0.05). The percentage of cows pregnant by 28 days after examination was 26.4\%, 18.9\%, 42.1\% and 31.4\% for Control, Split, CIDR and Split+CIDR groups, respectively (P<0.05). There was no overall effect of separate grazing on milksolids production or cow liveweights, but milksolids did vary between herds (P<0.001). Separate grazing did not enhance the reproductive performance of anoestrous cows. }, issn = {1176-5283}, author = {Clark BA and Rhodes FM and McDougall S} } @conference {41063, title = {Sex and age effects on genetic parameters for wool production and qualities}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {23-26}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Heritabilities and genetic correlations were estimated for New Zealand Romney sheep from within the selected and control lines of a 25-year selection experiment for greasy hogget fleece weight and yearling body weight. Average repeatability of clean fleece weight in 1 to 5 year-old ewes was 0.56, 25\% higher than the average heritability of 0.44. The average genetic correlation among measurements at different ages was 0.89. Sexual dichotomy in the relative predictive power of hogget records was most apparent for greasy and clean fleece weights but was evident to some degree for bulk and brightness as well, due mainly to lower heritabilities in male compared to female hoggets. Average co-heritability of greasy hogget with adult clean fleece weights was 25\% lower for male (0.26) compared to female (0.35) hoggets, in this case due to a lower genetic correlation (0.69 vs 0.81) as well as a lower heritability (0.33 vs 0.43, respectively). A repeatability model seemed an adequate approximation for estimation of breeding merit for most wool quality traits studied but not for lifetime wool production. }, issn = {1176-5283}, author = {Clarke JN and Dobbie JL and Jones KR and Wrigglesworth AL and Hickey SM} } @conference {41108, title = {Source of excess nitrogen may affect nutrient partitioning in lactating ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {158-161}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {This experiment tested the hypothesis that the form of surplus nitrogen (ammonia or amino acids) affects nutrient partitioning in lactating ruminants. Nine, abomasally-cannulated, 4 year old Coopworth ewes (66.4 {\textpm} 5.9 kg liveweight), suckling twin lambs were offered a basal diet designed to meet their requirements for ME and MP in 12 equal portions at 2 h intervals for two periods of five weeks. During both periods, ewes were allocated to one of three groups; continuous abomasal infusion of 2 l water/day (control), infusion of 150 g sodium caseinate (20g N) dissolved in 2 l water or 85 g ammonium bicarbonate (15 g N) in 2 l water. Liveweight change of ewes and lambs, ewe milk production and composition and nitrogen balances were measured. Treatments had no significant effect on ewe dry matter intake, in vivo dry matter digestibility or ewe liveweight change. Rela-tive to control, casein infusion increased milk production (33\%) and lamb liveweight gain (by 26\% from 132 to 166 g/day) but had no effect on milk composition. In contrast ammonia infusion decreased milk production (15\%), reduced milk protein concentration (from 63 to 56 g/kg), increased milk fat concentration (from 66 to 75 g/kg) and reduced lamb liveweight gain (from 132 to 66 g/day). The N apparently utilised (dietary N + infusate N – faecal N – urine N) was apportioned (milk N : body N) in ratios of 0.86 : 0.14, 1.0 : 0 and 0.52 : 0.48 for control, casein and ammonia infusions respectively. It is concluded that excess N in the form of ammonia diverted protein from milk production to body retention, thus the form of surplus N may affect nutrient partitioning in lactating ewes.}, issn = {1176-5283}, author = {Malik B and Nicol AM and Van Houtert M} } @conference {41100, title = {Suitability of serum oestrone sulphate measurement to verify pregnancy in red deer}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {131-133}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The mean {\textpm} s.e.m. concentration of oestrone sulphate (OS) in serum from 31 non-pregnant red deer was 2.0{\textpm}0.2 ng/ml. The value 3 standard deviations above this mean was 6.2 ng/ml which represents the highest serum OS concentration likely to be found in non-pregnant deer. Only 2 out of 40 serum samples obtained from 15 deer between 118 and 182 days pregnant had an OS concentration >6.2 ng/ml, the overall mean {\textpm} s.e.m. value for the 40 samples being 2.4{\textpm}0.3 ng/ml. On days 195 and 209 of gestation, 5 of 10 deer and 7 of 9 deer respectively had serum OS concentrations above 6.2 ng/ml; the mean {\textpm} s.e.m. concentrations on days 195 and 209 being 7.2{\textpm}1.3 ng/ml and 14.9{\textpm}3.4 ng/ml respectively. These results show that mean serum OS concentrations rise markedly in red deer during late gestation, and that by day 209 serum OS concentrations have risen above 6.2 ng/ml in most hinds. Measuring serum OS concentrations in the last month before expected calving may offer an alternative to ultrasonography for verifying pregnancy status in red deer. }, issn = {1176-5283}, author = {Henderson KM and Beatson N} } @conference {41128, title = {Synchrony of onset and cessation of breeding activity in brushtail possums (Trichosurus vulpecula) in coastal Otago, New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {229-232}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The onset of breeding was monitored in 117 female brushtail possums trapped at a single location between December and May, with reproductive status being determined at the time of capture. The cessation of breeding activity was monitored in captive animals in which reproductive status was determined in October (N=38), November (N=39) and January (N=30), by laparoscopic observation of their reproductive tracts. Comparison was made between animals that had pouch young removed (RPY) 7-9 days previously, and possums that had not had pouch young present for at least 40 days. Only 1/57 possums trapped over the period from 1 December to 31 March had recently bred. In contrast, 49/60 (82\%) possums captured between 1 April and 6 May, were either pregnant or had new-born pouch young. In spring (mid-October) 45\% of possums continued to cycle, only 13\% were cycling in late November and all were anoestrous in January. There were no relationships between liveweight or RPY and reproductive status. }, issn = {1176-5283}, author = {McLeod BJ and Thompson EG and Crawford JL} } @conference {41109, title = {Tactical supplementation of beef finishing cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {162-167}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The impact of high quality supplementary feeds on cattle growth rates was investigated in 2 experiments. The first experiment was conducted during late summer (8 weeks) and involved 5 treatments which were replicated twice: no supplement, 2 and 4 kg rolled maize grain/hd/d; and 2.3 and 4.6 kg DM/hd/d high quality pasture silage. The second experiment was conducted during late winter (8 weeks) and involved 3 treatments which were replicated twice: 0, 2 and 4 kg/hd/d rolled maize grain. Rising 2 year steers were used and all pre- and post-grazing pasture masses were similar between treatments within each experiment. During the summer experiment pasture quality was poor and steer liveweight gains for the 5 treatments were: -0.04, 0.44, 0.55, 0.29 and 0.36 kg/hd/d respectively. In contrast, pasture quality was high during the winter experiment and liveweight gains were: 0.93, 1.09 and 1.25 kg/hd/d respectively. The combined results of this experimental series show a consistent liveweight gain response to supplementation of high quality feeds, under both low and high quality pasture conditions. A general response of 0.15-0.20 kg liveweight gain/kg DM grain can be expected. Given current grain prices in New Zealand, its use as a tactical supplement in beef finishing systems will be confined to overcoming variable forage supply and attaining supply contract premiums. Pasture silage is an alternative supplement for summer, but high quality is a pre-requisite. }, issn = {1176-5283}, author = {Boom CJ and Sheath GW} } @conference {41133, title = {Toxicity effects of 1080 on pregnant ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {250-253}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {There are no data on the potential for 1080 used for pest control to cause delayed deaths or impaired productivity in livestock following multiple, sub-lethal doses. Recent losses of late-gestation ewes exposed to weathered 1080 baits has also led to speculation that pregnant ewes may be unusually sensitive to the toxin. To address these data gaps, groups of 20 Perendale ewes, non-pregnant or pregnant with twins, were administered either a single (0.25 mg/kg) or multiple oral doses (0.05 mg/kg over 3 consecutive days) of a 1080 cereal pellet. The highest mortality occurred in the single dose groups (pregnant 45\%, non-pregnant 21\%) compared to the multiple dose groups (pregnant 35\%, non-pregnant 0\%). There was no mortality in the control group of pregnant ewes. Log-linear modelling showed highly significant treatment effects (P = 0.0003) and differences (P = 0.045) in acute mortality rates between pregnant (40\%) and non-pregnant ewes (10\%), which was linked to increased bioavailablity. There were no differences in the incidence of metabolic diseases, lambing percentages, lamb survival, or growth rates between dosed and undosed pregnant ewes. This study demonstrated that extra care should be taken to avoid exposure of pregnant ewes to even small bait fragments, but also provides further evidence that there are no long-term health effects in animals that survive accidental 1080 poisoning. }, issn = {1176-5283}, author = {O{\textquoteright}Connor CE and Milne LM and Arthur DG and Ruscoe WA and Wickstrom M} } @conference {41087, title = {Ultrasonic pregnancy scanning - a tool for change}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {95-96}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The advent of ultrasonic pregnancy scanning has provided new opportunities for the management of breeding ewes. Major benefits of scanning are better allocation of feed resources and improved management at lambing, as well as being a tool to improve the genetic merit of flocks. Scanning results are also the catalyst for farmers focusing more clearly on their flocks{\textquoteleft} relative reproductive performances either informally through comparing scanning percentages and fertility indices with neighbours, or formally through comprehensive farm monitoring reports. }, issn = {1176-5283}, author = {McCorkindale AB} } @conference {41090, title = {Use of ultrasonic pregnancy scanning information for farmer extension}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {101-102}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Ultrasonic pregnancy scanning is a new technology that provides sheep farmers with information that can significantly improve flock performance. The effective use of this information requires participation from the scanner operators, consultants, scientists, veterinarians and company representatives. Farmer networks such as the Sheep Council and monitor farms also have an important role in maximising the benefits to individual farmers by sharing knowledge and experience on the management changes made possible by pregnancy diagnosis. }, issn = {1176-5283}, author = {Geenty KG} } @conference {41113, title = {Validation of body condition scoring by using ultrasound measurements of subcutaneous fat.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {177-179}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Visual assessment of body condition score (BCS) is used to aid individual cow and herd management, but the assessment is subjective and does not estimate actual body tissue reserves. Ultrasound (US) measurements of external fat reserves may be more objective. To quantify fat reserves at differing BCS{\textquoteleft}s, fat depth was measured by US on 87 mixed aged Friesian dairy cows on 6 occasions during a year. The US measurements were made at the 12th rib (RIB) and mid-way between the hip and pin bones (HIP). Animals were weighed (LW) and their BCS assessed visually at the same time. Mean BCS was greatest in early summer at 4.5 and lowest in late summer at 3.6. Mean RIB varied from 2.2 mm in mid spring to 3.6 mm in early winter, while mean HIP varied from 1.6 mm in early summer to 4.2 mm in early winter. Changes in BCS and LW were positively correlated. Age and growth in 2 year old animals did not appear to affect this relationship. BCS was positively correlated to both RIB and HIP fat depth. The correlation coefficient varied with time, being smallest in late summer (r = 0.37 \& 0.26 for RIB \& HIP respectively) and greatest in late lactation (r = 0.69 \& 0.82 for RIB \& HIP respectively). The ability of RIB \& HIP measurements to predict BCS was low when BCS was <4.5, but predictability increased as fat depth and body condition increased. Cows at lower scores may deposit or deplete fat internally while having few external fat deposits. Because large changes in liveweight (LW) occurred without changes in BCS, or US, it is possible that fat deposits are internal or intramuscular rather than subcutaneous, and therefore not detectable from external inspection. Since most BCS values are <4.5 for lactating cows, the value of ultrasound to assess fat depots in lactating dairy cows is limited; however it may be of some value with cows of BCS >4.5. }, issn = {1176-5283}, author = {MacDonald KA and Verkerk GA and Penno JW} } @conference {41077, title = {Variation in lamb survival within farm and between farms}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {73-75}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Variation in lamb loses between scanning and docking were investigated in 1997 in a survey and an on farm study. Ultrasonography results on MA ewes showed a range from 130 to 191\% foetuses scanned/ewes present. Ewe weights at joining ranged from 54 to 70 kg. Survival of multiple and single was 78\%, and 92\% respectively. Differences between scanning and docking comprised 21\% ewe deaths, 49\% dead lambs and 30\% missing /unseen. Paddock docking results were 157\% to 188\% for ewes with 2 lambs and from 90\% to 109\% for 1 lamb. Paddocks were assessed on the basis of slope, aspect, shelter, hazards and disturbance. Lack of shelter on easy contours, disturbance and steep slopes appeared to exacerbate lamb deaths. Adverse weather was not a factor in the year of this study. }, issn = {1176-5283}, author = {Tarbotton IS and Webby RW} } @conference {41082, title = {Vital components of industry-wide benchmarking}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {59}, year = {1999}, month = {Jan}, pages = {84}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {For the full benefits to be realised from farm monitoring and benchmarking it is essential that it is available to all farmers at an affordable price. The data must be relevant to participants, easily collected, and processed into a form that is easily understood. NZFT2000 is an example of how these principles can be put into practice for the benefit of individual sheep farmers and the whole sheep industry. }, issn = {1176-5283}, author = {Rohloff RM} } @conference {41030, title = {Amylin causes hypocalcaemia in lactating goats - Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {209-210}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Amylin is a 37-amino acid peptide, structurally related to calcitonin-gene-related peptide (CGRP), adrenomedullin and calcitonin (CT). It is co-secreted with insulin from the pancreatic {\ss}-cell. There is increasing evidence from rodent models that amylin may play an important role in the regulation of mineral metabolism, particularly Ca (Cooper, 1997). However, such a role has never been investigated in a ruminant model. The aim of this study was, therefore, to investigate a role for amylin in the regulation of Ca and metabolism of other minerals in lactating goats.}, issn = {1176-5283}, author = {Min SH and Farr VC and Lee J and Cooper GJS and Davis SR} } @conference {41000, title = {Arterio-venous differences of amino acids across the mammary gland of cows fed fresh pasture at two levels of dry matter intake}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {98-101}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Four cows housed indoors in metabolism stalls were used in a cross-over experiment to test the effect of two levels of dry matter intake on amino acid metabolism during early lactation (October). Fresh ryegrass/white clover pasture was offered ad libitum or at 75\% of the ad libitum intake during 2 experimental periods. Concentrations of essential amino acids (EAA) in arterial and mammary venous plasma were determined as indicators of the uptake and utilisation of individual AA for milk protein synthesis in the mammary gland. The relative concentrations of free EAA (expressed as \% of total EAA) of lysine, tyrosine, leucine, phenylalanine, methionine, tryptophan and histidine were lower in arterial plasma than those in the milk protein, suggesting these as limiting EAA. Using extraction rates of plasma as an indicator of potentially limiting amino acids, leucine, lysine and methionine appeared, in that order, as the most limiting amino acids in the ad libitum animals. In the intake restricted animals, the order of limitation appeared to change to methionine, lysine and leucine. }, issn = {1176-5283}, author = {Pacheco-Rios D and McNabb WC and Cridland S and Barry TN and Lee J} } @conference {41054, title = {The assessment of natural means of controlling loose wool feltability and yarn shrinkage.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {291-293}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Midside wool samples from Romney and {\textthreequarters} Romney {\textonequarter} Merino cross ({\textonequarter}M) hoggets were tested for loose wool feltability. Romney samples were also hand spun and yarn shrinkage measured. Sire progeny groups accounted for 6.5\% of the variation among samples in loose wool felting (P<0.10) and 12\% in yarn shrinkage (P<0.05). Fibre traits most highly correlated with feltball diameter were loose wool bulk (r = 0.65 for Romneys and 0.73 for {\textonequarter}M), crimp frequency (r= 0.53 and 0.41 respectively) and lustre (-0.30 and -0.40 respectively). Loose wool bulk (r= -0.25) and greasy fleece weight (r=-0.40) were most correlated to yarn shrinkage. These results suggest that low-shrinkage wools could be produced by selecting rams on shrinkage of yarn. Loose wool feltability might also be changed by direct or indirect selection. }, issn = {1176-5283}, author = {Kenyon PR and Wickham GA and Blair HT} } @conference {41001, title = {Balancing pasture and maize silage diets for dairy cows using urea, soybean meal or fishmeal}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {102-105}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Four treatment groups of 10 Holstein-Friesian cows were established at the DRC No. 2 dairy in the spring, summer and autumn of 1996/97 to test the efficacy of providing urea, soybean meal or fishmeal supplement to overcome the protein deficiency that occurs when cows are supplemented with large amounts of maize silage. Pasture allowance was manipulated to achieve an average pasture dry matter (DM) intake of 6.6kg/cow/day for each group. Treatment groups were supplemented with 75 MJ ME/cow/day as either 7.0kg DM of maize silage, 7.0kg DM of maize silage plus 90g of urea, 5.2kg DM of maize silage plus 1.4kg DM of soybean meal, or 5.8kg DM of maize silage plus 1.0kg DM of fish meal. The addition of urea as a source of non-protein nitrogen had no effect on milk, milkfat or milk protein production. Soybean meal increased milk protein production by 0.06kg/cow/day in both summer and autumn (P<0.01). Fishmeal increased milkfat production by 0.07 (P<0.01) and 0.08kg/cow/day (P<0.05) in summer and autumn and increased milk protein by 0.06 (P<0.01), 0.10 (P<0.01) and 0.08kg/cow/day (P<0.001) in spring, summer and autumn, respectively.}, issn = {1176-5283}, author = {MacDonald KA and Penno JW and Kolver ES and Carter WAC and Lancaster JAS} } @conference {41012, title = {Calpain and calpastatin activity in muscle from genetic lines of lambs selected for divergent levels of fatness.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {143-145}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {There is widespread interest in the extent to which genetic factors influence meat quality. In this study we examined meat quality characteristics and the activity of the calpain protease system in M. longissimus lumborum (LL) from backfat selection lines of Southdown lambs. The high fat line produced heavier carcasses with greater soft tissue depth GR. LL from the high fat line animals had a lower ultimate pH and was significantly more tender at 24h post-mortem using the MIRINZ tenderometer but not the Warner-Bratzler peak force. There was a decline in m-calpain and calpastatin activity but not m-calpain in the 9h post-mortem. There were no significant differences in the levels of the calpains or their inhibitor between high and low backfat lines. However, when the results were adjusted for pH, the 20 min calpastatin levels were highest for the sire group that had the highest peak force value. }, issn = {1176-5283}, author = {Morton JD and Bickerstaffe R and Purchas RW} } @conference {41032, title = {Calpain and tenderness comparisons in M. longissimus dorsi samples from weight-selected and control Angus cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {214-217}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Meat samples (M. longissimus dorsi) from a control Angus herd (ACO) and associated selection herd (AS1) were compared for calpain/calpastatin concentrations and shear-force tenderness, after the herds had been subjected to 22 to 24 years of random replacement or selection for increased adjusted yearling weight. The objective was to monitor changes in meat tenderness at fixed slaughter date resulting from genetic selection, and associated changes in muscle calpain or calpastatin concentrations. Bull calves (n=94), from 3 successive calf crops raised on pasture, were slaughtered immediately after arrival at the abattoir at about 20 months of age on one day each year (May 1995, 1996 and 1997). Carcasses were electrically stimulated, weighed and hot boned. Meat samples for calpain/calpastatin analysis were taken within 30 minutes of slaughter from the M. longissimus dorsi, with further samples after 24 hr of ageing at 10{\textdegree}C. Shear-force tenderness was assessed on the same muscle at intervals from 24 hr until one month of ageing at -1{\textdegree}C. Calpastatin, milli- and micro-calpain activities were assayed using casein as a substrate. Yearling live weights, hot carcass weights and muscle weights were respectively 19.0\%, 16.5\% and 17.3\% greater in the AS1 than the ACO herd (all P<0.001). The AS1 samples were on average 8 to 16\% more tender than ACO samples (P<0.05) on days 1 and 3 post mortem, but there were no significant herd differences in tenderness at later ageing times. The between-animal repeatability of shear-force tenderness from days 1 to 28 was 0.44{\textpm}0.07. Millicalpain concentrations were significantly lower in the AS1 than ACO samples by an average of 13\% (P<0.001), and there were smaller differences in microcalpain and calpastatin between herds in the same direction. These results show that early post mortem tenderness, millicalpain and possibly microcalpain and calpastatin concentrations were associated with genetic differences in growth. }, issn = {1176-5283}, author = {Morris CA and Speck PA and Cullen NG and Dobbie PM} } @conference {41031, title = {Is carcass classification useful or necessary?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {211-213}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The need for a N.Z. Meat Producers Board (NZMPB) supervised classification system for export carcasses has been widely debated by the farming community and elsewhere while the Producers Board Acts Reform Act (1997) has been discussed through parliament. Supervision of the export carcass classification is one of the remaining NZMPB (recently renamed Meat New Zealand) functions with the classification being undertaken by company graders. As meat companies select the carcasses most suited to provide the meat/cuts for particular meat export orders, they argue that a national carcass classification system is unnecessary. Today most carcasses are sold as cuts rather than as entire carcasses. Carcass exports provided the main reason for the initial development of a national classification system to facilitate trading overseas {\textquoteleft}sight unseen{\textquoteleft}. However carcass grading/classification also provides a common language of communication which, when associated with a payment system, allows producers to compare prices from different exporters and provides market signals as to the type of carcass most required. Export carcass classification indicates composition and yield of saleable meat. NZMPB supervising graders are seen as giving a independent check on company graders, a feature disliked by some processors but endorsed by most producers. A uniform national system as is current in New Zealand also provides good data on which to base any future production plans. If based on objective measurements, a national classification system could also be run concurrently with any company system with a computer printing out the results of both systems. It is important that producers receive back factual information on the carcasses they are growing with information on how well they fit market requirements. The recent passage of the Producer Board Acts Reform Act (1997) has noted that the compulsory carcass classification for beef is to be reviewed or phased out in one year and sheep classification system is to be reviewed in two years. Unless the Meat Industry Association agrees with their retention, they will be phased out. If this happens, it may place too much power in the hands of the industry player currently having access to most of the market information and farmers will have no way of comparing between processors. }, issn = {1176-5283}, author = {Kirton AH} } @conference {41016, title = {Cost-benefit analysis of commercial use of the Inverdale prolificacy gene}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {157-160}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The Inverdale prolificacy gene is one of several potential major genes currently being explored for commercial application to the New Zealand sheep industry. We calculated economic benefits of two strategies to breed Inverdale carrier stud rams using gene flow methodology. Strategy 1 involves continuous transition matings from a conventional stud flock to generate Inverdale carrier ewes while Inverdale carrier ewes are self replacing in Strategy 2. Strategy 1 involved less DNA testing per ram sold, resulting in a $140 saving in testing costs at $50 per test. Reduction in conventional genetic response was also lower for Strategy 1 (<5\% as opposed to 24\% for Strategy 2) although Strategy 1 requires closer monitoring of animal identification and some Inverdale rams must be kept to produce carrier ewes. Commercial Inverdale use was shown to be highly beneficial in an existing terminal sire mating system with an added value over a normal ram of $3350 per Inverdale ram purchased. This was also highly cost effective with an expected DNA test price of $50 to $75 per sheep genotyped. }, issn = {1176-5283}, author = {Amer PR and McEwan JC and Dodds KG and Davis GH} } @conference {40972, title = {Current status of a candidate gene marker for bloat susceptibility in cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {10-12}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Pasture bloat costs New Zealand{\textquoteleft}s dairy industry at least $25M annually. We have previously shown that a salivary protein is increased in abundance in saliva from cattle that have been selected for low susceptibility to bloat compared with those selected for high susceptibility. We have now obtained the cDNA sequence for two closely related forms of this protein, which we term bSP30a and bSP30b. These share 83\% sequence identity at the amino acid level, but at best only 28-30\% homology with salivary proteins from other species. Analysis of genomic DNA by PCR suggests that the two forms of bSP30 are coded on two separate genes. However, the function of bSP30 and how it might influence susceptibility to bloat remains as yet unknown. }, issn = {1176-5283}, author = {Wheeler TT and Haigh BJ and Wilkins RJ and McCracken JY and Morris CA} } @conference {41051, title = {The determination of sulphur in wool using near infrared reflectance spectrometry}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {281-283}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A method and calibration for estimating sulphur (S) concentration in wool using near infrared reflectance spectrometry (NIRS) is described. The NIRS measurements were calibrated against wet chemistry determinations of wool S (R{\texttwosuperior} = 0.81, relative standard error {\textpm} 3.7\%, n=339). The first derivative spectra with 14 partial least squares terms gave the lowest cross-validation error for the calibration using an independent set of wool samples (R{\texttwosuperior} = 0.78, cross-validation error {\textpm} 0.11, n=66, mean 2.88 g S/100g wool). The correlation spectrum gave a series of approximately equally weighted peaks from about 1300 - 2400 nm, corresponding to -NH stretching and bending modes (protein). The -SH absorption between 1736 and 1746 nm could also be identified. Although scouring differences contributed to marked spectral differences in the visible region (yellowness was related to the first 3 principal component scores) these did not affect the overall S calibration. Uses for the calibration include wool S as an indicator of lifetime wool production, changes in wool composition in response to supplemented cysteine or energy intake, and the relationship between wool S and wool characteristics. }, issn = {1176-5283}, author = {Corson DC and Martin W and Lee J} } @conference {41042, title = {Development of an experimental herd for investigating maternal contributions to fertility in recipient cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {248-251}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {In order to develop an experimental resource to understand the biology of superior recipients, each of 155 contemporary yearling heifers received 2 in vitro-produced embryos on 6 occasions during a 30-month period. The number of foetuses present were determined at Day 60 of pregnancy, and pregnancies terminated. Heifers were ranked for their aggregate pregnancy performance, and the highest and lowest 25 were retained. Mean pregnancy rates of all recipients ranged from 0.20 - 0.67 depending on transfer occasion. The mean {\textpm} s.e. pregnancy rate of the High and Low groups were 0.77 {\textpm} 0.07 vs. 0.11 {\textpm} 0.06 respectively (P<0.001). No significant differences were observed between the two groups in oestrous cycle progesterone profiles or follicular dynamics. We conclude that repeated twin embryo transfer can be used to identify recipients of high and low potential fertility, and that uterine, rather than simple ovarian parameters, may be better correlates with high pregnancy rate.}, issn = {1176-5283}, author = {McMillan WH and Donnison MJ and Cox SF} } @conference {40981, title = {Differential effects of short-term once-daily milking on milk yield, milk composition and concentrations of selected blood metabolites in cows with low or high pasture intake}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {41-43}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Forty-eight Friesian cows were subjected to ad libitum grazing (pasture allowance 45 kg/cow/day) or restricted grazing (pasture allowance 16-18 kg/cow/day) in a cross-over experiment during spring. Mean milk yields for ad libitum and restricted cows after 10 day treatment periods were 21.4 and 16.2 l/day respectively. All cows were then subjected to once-daily milking (ODM) for 2 days. ODM reduced milk yield and casein:whey protein ratios but increased concentrations of fat, serum albumin, immunoglobulin G, whey protein and somatic cells. Effects of ODM were greater in fully fed and thus higher-producing cows. In blood, ODM decreased concentrations of non-esterified fatty acids and urea, but increased concentrations of glucose. Milk yield and composition were significantly affected by short-term ODM, but the effect was less in cows producing below their peak due to feed restriction. There were metabolic indications that ODM reduced the nutritional demands of milk production.}, issn = {1176-5283}, author = {Auldist MJ and Prosser CG} } @conference {40984, title = {Diurnal variation in concentration of Beta-lactoglobulin in bovine milk.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {49-51}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Two trials were conducted to define the variation in concentrations of b-lactoglobulin (b-LG) in bovine milk following different milking intervals. In the first, milk samples were collected from three herds of 20 cows. At the time of sampling in early summer, one herd was in each of early, mid and late lactation (30, 120 and 210 days post calving, respectively). Average b-LG concentrations were 41, 37 and 50\% higher (p<0.05) after a 16h than 8h milking interval for early, mid and late lactation, respectively. In the second trial, bulk milk was sampled from four herds of 12 cows. All cows were at the same stage of lactation and the milking interval was 16:8h. Samples were collected on three separate occasions when cows were on unrestricted pasture intake and once when intake was restricted by 50\%. On unrestricted pasture intake, concentrations of b-LG were 11\% higher in milk collected after 16h than 8h milking interval, whilst on restricted intake, concentrations were 44\% higher. There were no differences in concentrations of a-lactalbumin (a-LA). Both trials show a significant difference in b-LG levels in milk collected after 16h versus 8h milking interval, although only 71\% of all samples collected in the first trial exhibited this difference and it was less in the second trial using bulk milk. }, issn = {1176-5283}, author = {McLaren RD and Auldist MJ and Prosser CG} } @conference {41033, title = {The Effect of Blood Sampling Site on Measures of Stress in Dairy Cattle - Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {218-219}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Stress has a negative impact on livestock production. Several physiological indicators currently exist to identify when animals are experiencing stress. Recently it has been suggested that the site of blood sampling may influence clinical pathologic parameters in rodents (Nasir et al., 1996). Because of the difficulty interpreting multiple physi-ological measures of stress and their high variation within animals we conducted a study to 1) determine the effect of blood sampling site on physiological measures of stress in dairy cows and 2) identify new quantifiable indicators of stress.}, issn = {1176-5283}, author = {Morrow-Tesch J and Whitehead K} } @conference {40988, title = {The effect of calving season on milk production. A system study.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {61-63}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A 3-year trial is being conducted at No1 Dairy Farm, Massey University, to compare the effect of calving season on the whole system of production, and the results of the first year are presented here. Three different systems were implemented by stocking each farmlet (40 ha) with Friesian cows which calved either in Autumn (A), in Spring (S) or 50\% in A and 50\% in S (A/S). Average stocking rate (SR) was 2, 2.25 and 1.95 cows per ha, respectively. A larger area was conserved as silage in A than in A/S and S, which also affected pasture growth rate in Spring. More supplements (t DM/cow) were fed in A (1.2) than in A/S (0.8) or in S (0.4). The higher yield of milk solids (MS) per cow for cows which calved in Autumn compensated the lower stocking rates of those herds and resulted in similar levels of production per ha (705-725 kg MS) for all three systems. These first year results suggest that similar levels of production per ha can be achieved with different calving systems and they emphasise the importance of farm systems studies as a research tool. }, issn = {1176-5283}, author = {Garcia SC and Cayzer FJ and Holmes CW and MacDonald A} } @conference {40987, title = {The effect of dairy herd management and milking practices on milk quality.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {56-60}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A mail survey to 200 dairy company suppliers in July 1996 received a 46\% response. Certain practices (e.g. SAMM (Seasonal Approach to Managing Mastitis) plan) reported by seasonal supply farmers were compared with their company{\textquoteright}s milk quality records for the 1995/96 year. An indicator of udder health was Bulk Milk Somatic Cell Count (BSCC). Mean BSCC (1995/96 lactation) for survey respondents was 217,000 cells/mL. 35\% achieved a seasonal average BSCC<150,000 cells/mL; 3\% had BSCC>400,000 cells/mL. Milksolids per hectare was significantly (p<0.01) and negatively correlated with BSCC. "Low BSCC" suppliers (<120,000 cells/mL) reported using similar dairy husbandry and milking procedures to the 65\% of suppliers with BSCC above 150,000 cells/mL. 45 \% with BSCC<250,000 cells/mL consciously used the SAMM plan compared to 22\% among those with BSCC>250,000 (p<0.05). Farm dairy hygiene, detection and treatment of mastitis infection (lactating or dry cow therapy), drying-off and culling of selected cows remain important practices for maintaining milk quality. }, issn = {1176-5283}, author = {Londono-Gutierrez P and Anderson WJ} } @conference {41038, title = {The effect of grazing management on pasture and animal production late Autumn to Early-Spring period in a one year Bull Beef Grazing System.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {236-238}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The aim of this trial was to improve pasture growth rate and animal liveweight gains in the late autumn and early spring on a one year bull beef production system. The trial was conducted at the Tuapaka bull unit, Massey University, from 1 April to 30 September 1997. It compared three contrasting managements, operating on a total of 165 bulls stocked at 2.6 bull/ha. Treatment 1 followed a grazing plan based on the average pasture growth rate for the region, the animal requirements needed to achieve performance targets, and pasture mass targets (2700-2800 kg DM/ha and 1500-1600 kg DM/ha for late autumn and early spring, and 3000-3200 kg DM/ha and 1100-1200 kg DM/ha for winter for pre-grazing and post-grazing, respectively). Treatment 2 was managed according to the same pre-grazing and post-grazing targets. In this treatment the pasture targets were monitored daily, and bulls were shifted when the post-grazing targets were achieved. No supplement was used in Treatments 1 and 2. Treatment 3 followed traditional Tuapaka management, based on a 50 day rotation over the late autumn and winter, a 30 day rotation in August, and set stocking in September. Supplement was fed to this treatment as required in the winter. The overall liveweight gain (0.84 {\textpm} 0.02, 0.87 {\textpm} 0.02, 0.74 {\textpm} 0.01 kg LW/head/day for Treatments 1, 2, and 3 respectively) and final liveweight (354.7 {\textpm} 3.54, 359.8 {\textpm} 3.65, and 335.6 {\textpm} 3.27) were similar for Treatments 1 and 2 which were both significantly higher (P<0.001) than Treatment 3. Net herbage accumulation was significantly different (P<0.01) between Treatment 1 (6147 {\textpm} 369.3 kg DM/ha), Treatment 2 (7062 {\textpm} 319.9 kg DM/ha), and Treatment 3 (5277 {\textpm} 334.08 kg DM/ha). It was concluded that it is possible to improve both pasture production and bull beef performance when grazing is based on the management of prescribed sward conditions. }, issn = {1176-5283}, author = {Coutinho HB and Matthews PNP and Morris ST} } @conference {40997, title = {Effect of luteolysis on control of ovarian follicles using oestradiol benzoate and progesterone in cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {89-91}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {This study aimed to determine whether progesterone from intravaginal insertion of a CIDR device could substitute for luteal progesterone and facilitate oestradiol benzoate (ODB)-induced control of ovarian follicle waves in the event of luteolysis. Luteolysis was induced by an injection of prostaglandin-F2a on Day 13 of the oestrous cycle in 24 lactating dairy heifers. Concurrent treatments on Day 13 were: i) 1 mg ODB i.m. (ODB1); ii) CIDR for 6 days (CIDR); iii) 1 mg ODB i.m. plus CIDR for 6 days (ODB1/CIDR); or, iv) 2 mg ODB i.m. plus a CIDR for 6 days (ODB2/CIDR). Examination of the ovaries using ultrasonography showed that oestrous cycles comprising 2 follicle waves predominated among ODB1 and CIDR groups; whereas combination treatments produced mostly 3-wave cycles (p<0.05). Day of ovulation was 15.4 {\textpm} 0.3, 21.2 {\textpm} 0.2 and 22.5 {\textpm} 0.2 for ODB only, CIDR only and 1 or 2 mg ODB plus CIDR cows, respectively (p<0.01). The interval from day of emergence to ovulation of the ovulatory follicle was less (p<0.01) in cows treated with ODB only (6.0 {\textpm} 0.3 days), or ODB plus a CIDR (7.2 {\textpm} 0.6 days), compared to a longer interval in those receiving a CIDR only (11.0 {\textpm} 0.8 days). These results showed that progesterone from a CIDR device was able to facilitate ODB-induced follicle wave turnover at the time of luteolysis in lactating dairy heifers. }, issn = {1176-5283}, author = {Burke CR and Morgan S and Clark BA and Rhodes FM} } @conference {41020, title = {Effect of maternal nutrition during early and mid gestation on fetal growth}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {175-177}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Two studies were conducted to examine the effects of maternal nutrition during early and mid-gestation on fetal growth. In the first, crossbred heifers were managed for High (H, 0.6 kg/day) or Low (L, 0.1 kg/day) live weight gains from mating until day 140 of gestation. Treatments were then reversed so that effects of nutrition during early gestation were not confounded by differences in maternal live weight at calving. Maternal liveweights (kg, Mean{\textpm}SE, n=30/group) were (L vs H) 350.6{\textpm}4.9 vs 394.3{\textpm}5.3 (P<0.001) at day 140 of gestation and 393.5{\textpm}5.3 vs 394.4{\textpm}5.8 (P>0.05) at term. Calf birth weights (L vs H) were 30.9{\textpm}0.7 vs 29.9{\textpm}0.8 kg (P>0.05). In the second study, 60 Romney ewes were allocated to three nutritional treatments, 0.5 maintenance (M), 1.0M or 1.5M from days 21 to 101 of gestation. At day 101, ewe liveweights were 45.8{\textpm}1.4, 56.8{\textpm}1.4 and 69.1{\textpm}1.4 kg respectively (P<0.001). Fetal weights at slaughter (day 101 of gestation) were 1249.9{\textpm}40.6, 1280.8{\textpm}38.0 and 1379.8{\textpm}35.2 g respectively (P<0.05). These results indicate that, although the fetus places a relatively small nutritional demand on the dam in early gestation, fetal development can in some situations be influenced by maternal nutrition, particularly when dams are over- rather than under-fed. }, issn = {1176-5283}, author = {Cooper K and Morris ST and McCutcheon SN} } @conference {41024, title = {Effect of pasture supplemented with methionine on wool growth and selected growth parameters}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {189-191}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The effects of a supplemental oral drench of rumen-protected methionine (Mepron{\textregistered}) on wool growth and weight gain was studied in 2-3y non-mated Romney ewes during nine months from March to December. Three groups of 20 sheep received either 0, 4 or initially 8 (later 2) g of methionine daily. The ewes were rotationally grazed as a single mob on ryegrass-white clover pasture with winter restrictions. Pasture availability was monitored weekly. Mid-side wool samples were taken at two-monthly intervals and analysed for yield. Full fleece samples were collected during end of trial shearing and analysed for yield, fibre diameter, colour, staple length, crimp and style. Sheep were weighed weekly and herbage intakes estimated in August and November. Blood samples for plasma cysteine determinations were collected in June, August and November. There were no significant differences between the control and 4g/d groups in clean wool growth from mid-side patches (mean 1260 mg/cm{\texttwosuperior}/d), greasy fleece weight (4.12kg) or final live-weights (63.1kg). Average estimates of pasture intake were non-significantly lower in supplemented sheep in August but approached significance in November (P<0.11). There were no treatment effects on wool growth rate or wool characteristics even though Mepron increased (P<0.05) plasma cysteine concentrations (umolar) (control 40.5 vs 4g/d 45.3) in June and in August (25.9 vs 31.1) but not in November. Weight-adjusted back-fats depths were lower in both supplemented groups compared to controls (P<0.05). We conclude that simple deficiencies in sulphur-containing amino acids were not limiting for wool production in these grazing sheep. }, issn = {1176-5283}, author = {Purchas BJ and Waghorn GC and Wickham GA} } @conference {41021, title = {Effect of prior ram-ewe contact on the ability of rams to stimulate early oestrus}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {178-180}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Ram-ewe contact when ewes are in anoestrus may reduce the ram{\textquoteleft}s ability to stimulate oestrous activity in ewes. Conversely, oestrus ewes increase the ram{\textquoteright}s ability to stimulate ewes, possibly by increasing plasma testosterone concentration (T). On 25 November, 400 Romney ewes and 12 Dorset teasers were each randomised into 2 groups. One group of ewes and rams were joined while the others were isolated from the opposite sex. On 14 January (day 0) half of each group of ewes was joined for 35 days with either rams which had been previously exposed or not exposed to ewes, and mating marks were recorded each week. In a second experiment, 16 Romney rams were introduced (day 0) to oestrus or non-oestrus ewes and bled on days -1, 0, 2 and 5, and the blood plasma analysed for T. Rams not previously exposed to ewes stimulated more ewes to exhibit oestrus by day 35 than rams previously exposed to ewes (46\% vs. 30\%; P<0.01). Ewes previously exposed and those not exposed to rams responded similarly to ram stimulation, and by day 35 there was no difference in percentage of ewes mated. Both oestrus and anoestrus ewes increased T in rams on day 0. On day 2, T had returned to day -1 levels for rams with anoestrus ewes but increased further in rams with oestrus ewes (0.67 vs. 2.34 ng/ml; P<0.05). }, issn = {1176-5283}, author = {Knight TW and Ridland M and Litherland AJ} } @conference {41003, title = {The effect of secondary compounds of birdsfoot trefoil and red clover on dairy cow grazing preferences}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {110-112}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The responses of grazing animals to specific plant secondary compounds were examined in trials in which dairy cows grazed spaced plants of either birdsfoot trefoil (Lotus corniculatus L.) with high and low concentration of extractable condensed tannins (2.54 and 0.62 \% in the DM respectively for high and low tannin genotypes), or red clover (Trifolium pratense L.) with high and low formononetin concentration (0.68 and 0.29 \% in the DM respectively for high and low formononetin genotypes). Plants were established in 4 linear sequences of 26, each providing three blocks (replicates) of balanced sets of 2 plant species, 2 concentrations of test components, and plants either not trimmed or trimmed to minimise physical differences between genotypes within species. The sequences were grazed by four trained cows and selective behaviour was determined by the number of grazing bites per plant. Observations were repeated in March (P1) and April (P2). On average, animals grazed more on non-trimmed than on trimmed plants (7.6 vs 3.1 {\textpm} 0.711 bites/plant in P1, P=0.0001; and 8.4 vs 3.6 {\textpm} 0.858 bites/plant in P2, P=0.0002), but did not show clear discrimination between red clover and lotus (6.3 vs 4.4 {\textpm} 0.711 bites/plant in P1, P=0.053; and 6.3 vs 5.7 {\textpm} 0.858 bites/plant in P2, P=0.620). However, though the distribution of bites between red clover plants with high and low formononetin was similar (7.2 vs 5.5 {\textpm} 0.76 bites/plant in P1, P= 0.130; and 7.3 vs 5.3 {\textpm} 1.08 bites/plant in P2, P= 0.191), they showed strong preference for low condensed tannin concentration in lotus ( 2.1 vs 6.6 {\textpm} 1.11 bites/plant in P1, P= 0.0068; and 3.9 vs 11.1 {\textpm} 1.35 bites/plant in P2, P= 0.069). }, issn = {1176-5283}, author = {Poli CHEC and Hodgson J and Arnold GC and Cosgrove GP} } @conference {41010, title = {Effect of sire genotype on lamb growth and carcass productivity}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {136-139}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The growth and carcass traits of 774 lambs out of Romney ewes and sired by Suffolk (S), Landcorp Lamb Supreme (LS), Texel (T) and Romney (R) rams were compared when slaughtered on five occasions (groups 1 to 5): November 1995, February, March, May and July 1996. Forty carcasses per slaughter group were dissected into commercial cuts of saleable meat, fat trim and bone. S- and LS-sired lambs had heavier pre-slaughter liveweights than T-sired lambs (38.4 {\textpm} 0.27, 38.5 {\textpm} 0.26, vs 36.3 {\textpm} 0.27 kg respectively; P<0.001), which in turn were heavier than R-sired lambs (35.0 {\textpm} 0.29 kg; P<0.001). S-sired lambs had heavier hot carcass weights than both LS- and T-sired lambs in slaughter groups 4 and 5 (+0.9 to +1.9 kg; P<0.01); R-sired lambs were significantly lightest in all slaughter groups (-0.7 to -3.9 kg; P<0.05). S- and R-sired lambs had greater adjusted GR tissue depths than LS-sired lambs in later slaughter groups. T-sired lambs were generally intermediate between LS- and R-sired lambs. R-sired lambs produced less weight of saleable meat than S-, LS- and T-sired lambs (by 1.4 to 1.7 kg; P<0.01). Lambs sired by Landcorp{\textquoteright}s terminal sire breeds out-produced those sired by the company{\textquoteright}s maternal R sire breed. S-sired lambs exhibited rapid growth early in the season, but increased fat levels later in the season compared with LS-and T-sired lambs. }, issn = {1176-5283}, author = {Nicoll GB and Skerritt JW and Dobbie JL and Grimwood TJ} } @conference {41023, title = {Effect of sperm dose, diluent type and timing of insemination on pregnancy rates in sheep.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {186-188}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Low sperm numbers and ambient temperature storage are two important factors in the successful AI system for dairy cattle in New Zealand. Similar technologies with ram semen are required before the establishment of a similar AI system within the NZ sheep industry is feasible. A trial involving a total of 1200 Romney ewes was conducted in April 1997 to examine the effects of inseminate dose (50, 25, or 5 x 10--6 sperm) of semen held for up to 9 h at 20{\textdegree}C in two diluents (RSD-1 and Tris + egg yolk). In the first half of the trial ewes were laparoscopically inseminated with semen from Finn rams at set times (49 and 56 h) after CIDR removal, while in the second half of the trial ewes were inseminated with semen from Romney rams following the detection of oestrus, after CIDR removal, resulting in insemination times of 26, 44 and 49 h post removal. Returns to service in the cycle following AI were recorded and ewes were scanned for pregnancy 50 days post AI. There was a significant difference between ram breeds in pregnancy rate (Finn 63.2 \% v Romney 50.2 \% ; P<0.05). There were no effects of inseminate dose nor of diluent. Time to onset of oestrus was affected by ewe live weight (P<0.05) with the heavier ewes showing a trend for an earlier onset but there was no overall effect of ewe weight on fertility. The effect of time to onset was reflected in an effect of time from CIDR removal to AI in the second half of the trial, with ewes AI{\textquoteright}d within 30h of CIDR removal having a 10\% lower fertility. These results indicate that acceptable fertility can be achieved with semen dose rates 5 to 10 fold less than normal, thereby increasing the number of inseminations available per ejaculate. Improved synchrony methods seem imperative to obtaining better fertility from AI. }, issn = {1176-5283}, author = {Smith JF and Parr J and Murray GR and Clarke A and Oliver JE and Duganzich DM} } @conference {41004, title = {The effect of stage of lactation and season on milksolids response to supplementary feeding of dairy cows.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {113-116}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A factorial design was used to determine the effect of offering cows (n=8) in early, mid, and late lactation 50 MJME/cow/day of rolled maize grain (T2) or a nutritionally balanced supplement (T3) in spring, summer, autumn and winter at a restricted pasture allowance. The average milksolids production of the early, mid and late lactation groups was 1.16, 1.10, and 0.96 kg MS/cow/day ({\textpm} 0.013), respectively. When compared to a non-supplemented control (T1), offering T2 and T3 supplements increased MS production from 0.91 to 1.14 and 1.13kg MS/cow/day (P<0.01), respectively. The milksolids responses to T2 was 150g MS/cow/day greater in summer and winter than in spring and autumn (P<0.05). Stage of lactation, or form of supplement, had no effect on milksolids response (P>0.05). These results suggest that the milksolids response to supplementary feeding was determined by the extent supplementary feeding increased total ME intake. }, issn = {1176-5283}, author = {Penno JW and Holmes CW and MacDonald KA and Walsh BJ} } @conference {41027, title = {Effect of zinc oxide treatment for facial eczema on the copper status of Romney sheep grazing ryegrass pastures}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {199-201}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The copper (Cu) status of grazing Romney sheep was monitored following treatment with zinc oxide (ZnO). In a series of experiments sheep of various ages were treated with ZnO as either an oral drench weekly for one year, or as an intraruminal controlled release bolus (Time CapsuleTM , AgResearch) once (on day 0) or twice (on day 0 and 40), in two consecutive years. Measurements of Cu status included Cu concentrations in liver, kidney and muscle in all animals, and liver metallothionein (MT) in sheep dosed with ZnO orally. Drenching of two-year old wethers with 12 g ZnO/week for 52 weeks did not significantly change Cu liver concentration compared to untreated control animals (mean {\textpm} SD, 1.93 {\textpm} 0.88 and 1.67 {\textpm} 0.87mmol cu/kg FW, respectively). However, administering a single 42-day intraruminal ZnO bolus to six-month old lambs resulted in decreased liver Cu concentrations after 40 days (0.96 {\textpm} 0.06 compared to 1.33 {\textpm} 0.07 mmol Cu/kg FW in controls; P<0.001). When lambs which were growing at 100g/day were treated with a second ZnO bolus and evaluated after an additional 40 days, Cu liver concentrations were reduced by a further 20\% but this change was not statistically significant (P=0.07). The variable effects of different forms of Zn treatment on liver Cu concentration are discussed in terms of duration of the dose, age of the animals, DM intake, initial Cu pool size in the liver, and Cu/Zn-binding MT. Under most conditions the benefits of ZnO as an effective facial eczema control are likely to outweigh any short term reduction in liver Cu. }, issn = {1176-5283}, author = {Rounce JR and Knowles SO and Grace ND and Lee J} } @conference {41025, title = {The effects of a cation-anion balanced diet on calcium and phosphorus metabolism in growing lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {192-194}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {During the past decade, there has been renewed interest and research in the role of the dietary cation-anion balance (DCAB) in controlling Ca and P homeostasis. Two diets differing in DCAB (either high DCAB, 250 meq/kg DM, or low DCAB, -100 meq/kg DM) were fed to 10 Romney lambs. Feeding low DCAB decreased urine pH by 2.0 pH units; from 8.2 (SE=0.45) to 6.2 (SE=0.50), indicative of the anticipated changes in the ionic balance associated with alterations in the dietary CAB. Plasma concentrations of Ca and P, and whole-body Ca and P balance (intake-excretion) were similar for both groups of sheep. Reducing the dietary CAB caused a 7-fold increase in the urinary excretion of Ca (low DCAB 0.75 g/day vs high DCAB 0.11 g/day; P=0.001).The apparent absorption of Ca in the low DCAB and high DCAB groups were 1.6 and 1.3 g/day, respectively, although there was no significant difference between the two groups. These data indicate that lowering the DCAB increases urinary excretion of Ca of growing lambs without affecting Ca balance due to an alteration in the movement of Ca to and from bone. Similar changes in Ca absorption and utilisation have been observed in dairy cows, suggesting that the growing lamb is a suitable model for future studies in the regulation of Ca homeostasis in dairy cattle. }, issn = {1176-5283}, author = {Wilson KL and Min S and Revell DK and Lee J and MacKenzie DDS and Cottam YH and Davis SR} } @conference {41029, title = {The effects of Insulin-nutrient supply interactions on ewe lactation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {205-208}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Six lactating abomasally cannulated ewes were subjected to a hyperinsulinemic euglycemic clamp with or without casein supplementation in a two period crossover design experiment. There was a significant response in milk (1169 {\textpm} 46 g/d vs 952 {\textpm} 46 g/d, P<0.001) and milk protein (66.4 g/d {\textpm} 2.7 g/d vs 54.2 g/d {\textpm} 2.7 g/d P<0.006), yield from casein supplemented ewes. There was no overall effect of the clamp on milk and milk protein yield, while the interaction was also non-significant. However, there was a significant reduction in feed intake (P<0.001) as the clamp continued, which may have compromised milk and milk protein response. There was also a significant period effect across all the measured parameters, which could also be a stage of lactation effect, due to the rapid decline of milk production during ewe lactation. In this study, in contrast to concentrate-fed cows, the utilisation of this technique did not increase milk protein yield in pasture fed lactating ewes. }, issn = {1176-5283}, author = {Back PJ and MacKenzie DDS and Davis SR and Harris PM} } @conference {40994, title = {Effects of oestradiol benzoate by injection at CIDR insertion for the treatment of postpartum anovulatory anoestrus in dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {82-84}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The effect of an intramuscular (im) injection of oestradiol benzoate (ODB) at insertion of an intravaginal progesterone-releasing device (CIDRTM, InterAg, NZ) during hormonal treatment for postpartum anoestrum in dairy cattle was investigated. Inclusion of injected ODB at CIDRTM insertion in synchronisation programmes for cycling cows can increase fertility, possibly by initiating an emergence of a new ovarian follicle wave with resultant improved oocyte competence. A total of 882 cows, of mixed age and breed from 18 herds, were examined and diagnosed as anoestrous during the week preceding each herd{\textquoteright}s planned start of mating. Cows were allocated randomly as controls or to receive 0.5 or 1 mg ODB (Oestradiol Benzoate Inj., Intervet, Netherlands) by im injection at CIDRTM insertion. The device was removed after 7 days, and any cow which was not observed in spontaneous oestrus within 48 h received 1 mg ODB im (CIDIROLTM Injection, InterAg, NZ). Cows with an observed heat within 12 days of CIDRTM removal were defined as responders, and returns to service in the subsequent 30 days were recorded. There were no significant differences between the control, 0.5 and 1 mg ODB treatments for either the proportion responding (89.5\%, 89.4\% and 90.9\%, respectively) or returning (52.3\%, 50.3\% and 55.4\%, respectively); however the proportions of cows observed in spontaneous oestrus varied by treatment (P<0.01; 28.5\%, 22.9\% and 17.2\% for control, 0.5 and 1 mg ODB treatments, respectively). Conception rates were not significantly affected by treatment (35.9\%, 42.5\% and 43.2\% for control, 0.5 and 1 mg ODB treatments, respectively). Of cows which did not become pregnant to the induced oestrus, 21.7\%, 20.7\% and 29.9\% for control, 0.5 and 1 mg ODB treatments respectively, returned to service with an interval of more than 24 days. These observations suggest that an injection of ODB at CIDRTM insertion may alter follicle wave patterns in cows with PPA, but that this may not result in increased conception rate, and might be detrimental to ovarian activity in a proportion of cows. }, issn = {1176-5283}, author = {Verkerk GA and Taufa VK and Morgan S and Clark BA and Macmillan KL} } @conference {40989, title = {Effects of selection and crossbreeding on industry returns from whole milk powder, butter and casein in the New Zealand dairy industry}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {64-67}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The effects of selection and crossbreeding on New Zealand dairy industry return were evaluated with a deterministic simulation model over 25 years. Several crossbreeding strategies involving Holstein-Friesian (F), Jersey (J) and Ayrshire (A) cattle were evaluated. These strategies were straightbreeding, upgrading to F (UPGF), upgrading to J (UPGJ), upgrading to A, and two- and three-breed rotational crosses. Total production of milk, fat, protein, lactose and ash were calculated assuming that 12,000 kg dry matter/ha was eaten for 1,224,911 ha. Yields of standardised whole milk powder (WMP), casein and butter were calculated. For the base year all the protein was utilised in WMP and for subsequent years, some increases in protein were sold in the form of casein. Casein and WMP were valued at $6.00 and $3.31 per kg respectively over the 25 years, whereas butter was valued at $3.00 per kg for base year production levels and $0.45 per kg for marginal increases in production. Production for the base year was 9,874 million l milk, 467 million kg fat, 359 million kg protein and 464 million kg lactose which yielded 1,263 million kg WMP and 157 million kg butter for an industry return of $4,646 million. Relative to the base year, UPGF resulted in the largest increase in WMP (128 million kg, 10\%), the lowest increase in casein (36 million kg) and increased returns by $639 million (14\%). UPGJ resulted in the lowest increase in WMP (73 million kg, 6.0\%), the largest increases in butter (67 million kg, 43\%), casein (65 million kg) and returns ($662 million, 14\%). Two-breed rotational (F,J) resulted in product flows for WMP and butter that were above the intermediate between UPGF and UPGJ but return that was equal to UPGJ. Selection within-breed in combination with crossbreeding can increase industry returns. However, the net financial outcome of all changes must be assessed taking into account farm expenses, income from culled stock and factory costs in processing milk with different composition in order to determine optimum crossbreeding strategies. }, issn = {1176-5283}, author = {Lopez-Villalobos N and Garrick DJ and Spelman RJ and Holmes CW and Blair HT} } @conference {41055, title = {Effects of sire and body site on wool colour measurements in Romney x Perendale progeny}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {294-297}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Six Romney rams were selected, three for "Bright" and three for "Yellow" wool, using estimates of breeding values for base wool colour. Six hundred Perendale ewes were randomly allocated to these rams in a single sire groups and joined for one mating cycle. Female progeny (n=280) were identified and grazed in one mob until weaning then split into two, one on Invermay and the other on Woodlands. Shoulder wool strip samples were collected at 3, 9, 12 months of age, two-tooth and as 2 year old ewes. The wool characteristics of yield, fibre diameter, resistance to compression and tristimulus colours were measured. No significant sire effect was found for tristimulus Y values at any sampling interval. A significant (P<0.05) tristimulus Y-Z difference was found for two tooth fleeces in progeny of Yellow sires compared with Bright (5.3 vs. 4.4 SED 0.4). Belly and back site wool was significantly (P<0.05) more yellow (Y-Z 7.8 and 6.1) than other body sites, belly wool was also lower (P<0.05) for brightness (Y 47.9) than other sites. The most significant source of variation in tristimulus Y and Y-Z values was contributed by body regions of fleece, emphasising the importance of effective skirting of fleeces. }, issn = {1176-5283}, author = {Wuliji T and Dodds KG and Andrews RN and Turner PR and Wheeler R} } @conference {41007, title = {Evaluating the business risk associated with feeding supplements to dairy cows on pasture}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {125-127}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The beta analysis technique provides a practical tool for evaluating the business risk associated with feeding supplements to dairy cows. The break-even cost, the expected profitability and the probability of making a profit can all be derived by predicting the marginal milksolids (MS) response, and applying prices for MS and supplements. The range of possible outcomes is simulated from specified maximum and minimum values, and the associated response distribution for each of these variables. The profitability of feeding maize silage on a market milk supply dairy farm was used to demonstrate the possible application of formal risk analysis to dairy herd management with a 50\% spring: 50\% autumn calving pattern. To be profitable, the marginal response to maize silage has to be maximised when no milk premium is paid, but, in the months when a premium is earnt, the risk of not making a profit is small. }, issn = {1176-5283}, author = {Laborde D and Shadbolt NM and Parker WJ} } @conference {41013, title = {Examination of selection index weights for lamb production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {146-149}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Economic values for lamb production have historically been derived with the assumption that lambs are slaughtered at a constant age. However, Landcorp Farming Limited slaughters lambs when they reach a set carcass weight. After weaning, heavier lambs are given preferential feeding and slaughtered when they reach a predicted carcass weight of 15kg. In this study index weights for weight of fat (FAT) and weight of lean (LEAN) in the carcass are calculated based on the different costs and returns associated with finishing lambs at a set weight. The nonlinear profit function was responsible for a positive index weight being derived for FAT. This result highlights the problems with using FAT and LEAN as selection criteria for lamb production. It is pointed out that FAT and LEAN are not breeding objectives for sheep production, and that it may be possible to use selection criteria better related to the profit function. }, issn = {1176-5283}, author = {Skerritt JW and Amer PR and Nicoll GB} } @conference {41040, title = {Exercise effects on muscle glycogen concentration in beef cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {243-244}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Low ultimate-pH of beef is desirable because it increases shelf life and has beneficial effects on colour and tenderness. Industry recommendations are that beef animals are not exercised strenuously prior to trucking, as this may trigger depletion of muscle glycogen and lead to higher beef pH. In 2 experiments, 400-500 kg 18-month-old steers were exercised at a range of intensities up to 5 km distance at 8 km/hr. Biopsy samples from the longissimus dorsi muscle were taken and glycogen concentration measured. Although plasma lactate levels were elevated by exercise there was no significant depletion in muscle glycogen concentration (average 17.7 mg/g tissue). Depletion may have occurred had animals been heavier and fatter, or if the exercise regime had been more severe. Alternatively, it may be that at the level of exercise imposed (which was severe by farm-practice standards), animals also needed to be emotionally stressed in order to precipitate a depletion of glycogen, through a combination of muscle contractile and adrenergic reactions. }, issn = {1176-5283}, author = {Lambert MG and Knight TW and Cosgrove GP and Anderson CB and Death AF and Fisher AD} } @conference {40971, title = {Experimental designs for Quantitative Trait Loci detection in the New Zealand dairy industry}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {6-9}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Detection of loci that affect quantitative traits such as milk production has been undertaken with daughter and granddaughter designs in the N.Z. dairy industry. Two other experimental designs, selective DNA pooling of trait extremes and the use of first cross Holstein-Friesian{\textendash}Jersey bulls, offer the opportunity to detect more loci than the current two designs. Selective DNA pooling involves the collective pooling of DNA from daughters at each extreme (high and low) of the trait distribution. A sire family of 100,000 daughters with DNA pools created from the top and bottom 1\% of progeny pooled has the same power (probability of detection) as approximately 5,000 progeny being individually genotyped with less than 1\% genotyping effort. Crossbreeding in the New Zealand dairy industry opens up the opportunity to identify QTL alleles that contribute to the genetic differences between the two breeds. Identification of breed specific QTL alleles can be achieved at a power of 90\% based on some 600-1500 progeny from matings of F1 Holstein-Friesian x Jersey bulls to F1 cows.}, issn = {1176-5283}, author = {Spelman R and Lopez-Villalobos N and Garrick D} } @conference {40993, title = {Factors influencing the prevalence of postpartum anoestrus in New Zealand dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {79-81}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The aim of this study was to determine the association between age, interval from calving (PPI) and breeding worth (BW) and prevalence of postpartum anoestrus (AA), as well their effect on response to hormonal treatment by anoestrous dairy cows. Individual cow details were collated from 6649 cycling and 2446 AA animals in 29 herds. Probability of AA was influenced by herd and was negatively related to PPI and age (p<0.001); but was not related to BW (p>0.05). Response of AA cows to treatment with progesterone and oestradiol benzoate was evaluated using a subset of 1482 anoestrous cows. Within 7 days of treatment, oestrus was detected in 87.1\% cows and conception rate to insemination during this period was 42.2\%. Oestrous response varied between herds but was not influenced by BW, PPI or age (p>0.1). Conception rate was positively related to PPI (p<0.001), but was not influenced by BW or age (p>0.1). It is concluded that in commercial dairy herds the likelihood of a cow being AA is greatest in young and recently calved animals, but is not influenced by breeding worth.}, issn = {1176-5283}, author = {Rhodes FM and Clark BA and Nation DP and Taufa VK and Macmillan KL and Day ML and Day AM and McDougall S} } @conference {40979, title = {Future opportunities in livestock production and biomedicine from advances in animal cloning}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {32-35}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Recent international advances in animal cloning technology have enabled the production of offspring from cultured cells derived from either embryos, foetuses or adults. When the current nuclear transfer process becomes more efficient, there will be three main applications for agriculture. These include: (1) the rapid dissemination of animals with the desired genetic characteristics; (2) the use of cloning for phenotypic evaluation of animals; and most significantly, (3) the production of genetically modified animals. Nuclear transfer will be combined with gene targeting technology to introduce precise genetic modifications to the cultured cells in the laboratory, resulting in the production of cloned transgenic farm animals. It is anticipated that this will herald a new era in biotechnology, with opportunities to generate animals for various biomedical applications and with modified livestock production characteristics. }, issn = {1176-5283}, author = {Wells DN and Misica PM and Tervit HR} } @conference {41011, title = {Genetic parameters for liveweight and live animal ultra-sound fat and eye muscle dimension in a synthetic terminal sire breed}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {140-142}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {During 1993-97, approximately 7000 lambs were weighed at weaning (WW), re-weighted (LW) and ultrasonically scanned for subcutaneous fat depth (FD) and eye muscle dimensions (depth (MD) and width (MW)) at 6 months of age. Animals belonged to Landcorp{\textquoteleft}s {\textquoteleft}Lamb Supreme{\textquoteleft} terminal sire breeding programme, derived in 1989-91 from mainly Romney ewes mated to Romney, Wiltshire, Coopworth, Texel and Poll Dorset sires selected for fast growth and leanness. Records representing the selection criteria were analysed by univariate and multivariate animal-model REML methods able to take account of the effects of selection on variance components. Heritabilities were higher for LW (0.33 {\textpm} 0.03) than WW (0.28 {\textpm} 0.03) and litter contributions (as a proportion of phenotypic variance) lower (0.29 {\textpm} 0.02 and 0.44 {\textpm} 0.02, respectively). Heritability estimates for all traits were similar in both sexes except for MW, which was higher in females (0.34 {\textpm} 0.05) than males (0.23 {\textpm} 0.05). Averaged across sexes, estimates were: FD (0.30 {\textpm} 0.03), MW (0.29 {\textpm} 0.04) and MD (0.33 {\textpm} 0.03), litter contributions being lower for FD (0.13 {\textpm} 0.02) than MW (0.22 {\textpm} 0.01) or MD (0.19 {\textpm} 0.02). MD was closely related genetically with MW (0.97 {\textpm} 0.01), but less closely associated with LW (0.44 {\textpm} 0.06) than was MW (0.57 {\textpm} 0.05). Both muscle traits showed similar genetic correlations with FD (0.48 {\textpm} 0.07 for MW; 0.43 {\textpm} 0.07 for MD). Parameter estimates indicated positive genetic trends for LW (regression of estimated breeding values on year of birth) more than two-fold higher than those previously published, and with little concomitant increase in FD. }, issn = {1176-5283}, author = {Clarke JN and Nicoll GB and Mowat CM} } @conference {41039, title = {Grain supplementation of finishing beef cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {239-242}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Low pasture quality in summer-autumn and feed deficits during winter are major constraints to achieving consistently high growth rates in beef cattle finishing systems. Two experiments were run to investigate the tactical use of grain supplementation as a tool to overcome performance constraints during these seasons. The first experiment was conducted during January-March (8 weeks) and involved 4 supplementation treatments: 0, 2, 4, and 6 kg grain supplement/hd/d. The second experiment was conducted during July-August (8 weeks) and also involved 4 supplementation treatments: 0, 1, 2, and 4 kg/hd/d. Rising 2 year steers were used in these experiments and pre- and post-grazing herbage masses were similar for all treatments within each experiment. During the summer experiment, steer liveweight gains were 0.05, 0.43, 0.65 and 0.80 kg/hd/d for the 4 supplementation levels respectively. During the winter experiment, average liveweight gains were 0.89, 1.08, 1.30 and 1.35 kg/hd/d. After grain supplementation ceased, liveweight advantages were eroded by compensatory gain occurring in the lower supplementation treatments. The average liveweight response to grain was similar in both experiments (0.18 kg liveweight gain/kg DM supplement), but was highest and most consistent at the 2 kg/hd/d supplementation rate. Acidosis was evident in 1 replicate of the highest supplementation treatment in each experiment. The use of a grain supplement can give reliable weight gain responses and could be valuable as a tactical tool to ensure that time and market bound supply contracts are fulfilled during difficult seasons. The use of this practice in systems that supply to commodity markets is unlikely to be economic. }, issn = {1176-5283}, author = {Boom CJ and Sheath GW} } @conference {41043, title = {Growth and carcass composition of Angus steers raised together from birth and managed on two post-weaning nutritional}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {252-255}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Two groups of 33 Angus steers aged 270 days and weighing 179 {\textpm} 2.1 kg were allocated after weaning to 2 pasture regimes designed for high (H) and low (L) mean Liveweight. When the treatments finished after 138 days liveweights were 242 {\textpm} 3.7 kg (H) and 218 {\textpm} 3.7 kg (L). Both H and L groups were then grazed together on pasture until slaughter at 30 months of age. At slaughter fat depth at the 12th rib, weight of kidney and channel fat, ribeye area, and the trimmed fat, bone and lean (90\% visual lean) were measured from the right side of the carcass. Carcass weight was the same for both treatment groups (258 {\textpm} 2.5 kg). The L group had faster liveweight gain than the H group for 283 days after treatment, but not thereafter. Steers from the L treatment had more kidney and channel fat (P<0.02). A significant (P<0.01) regression coefficient of 0.05 {\textpm} 0.019 for carcass weight on kidney and channel fat weight existed for steers in the H group, but not the L group. Rate of live weight gain before weaning was significantly (P<0.01) related to the weight of trimmed bone and lean at slaughter. Differences between animals in live weight gain at the end of the treatment period affected the weight of kidney and channel fat in the L group (P<0.01), and the weight of trimmed fat in the L group (P<0.05). These results are discussed in context of effects of growth rate on tissue development in cattle. }, issn = {1176-5283}, author = {Pleasants AB and Barton RA and Ball AJ and Oddy VH} } @conference {40990, title = {Growth curves and productivity of Holstein-Friesian cows bred for heavy or light mature live weight}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {68-72}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {This paper presents data for live weights (LW) from birth to maturity, and for yields of milk and milksolids (MSY) per lactation, from two lines of Holstein-Friesian cows bred for heavy (H) or light (L) mature LW. Compared with the Brody, Gompertz and Logistic functions, the Von Bertalanffy function provided the best fit to the LW data, and prediction from this function has been used in the following analyses. The breeding values (BV) for LW of the sires (H: 86.3 kg; L: 31.0 kg) and maternal grandsires (MGS) (H: 55 kg; L: 38 kg) used to develop the H and L LW lines were higher (P<0.001) for the H line than for the L line, and they were significantly associated with the actual birth weight (H: 41 kg; L: 35 kg) and mature live weight (H: 520 kg; L: 467 kg) of the cows. The heavy sires also had significantly higher BV for yield of milk (H: 1037 l; L: 737 l), milkfat (H: 33.0 kg; L: 27.5 kg), and milk protein (H: 31 kg; L: 22 kg), and the H cows produced more milk (H: 4708 l; L: 4323 l), and MSY (H: 364 kg; L: 348 kg) than the L cows. However, L sires had slightly higher (P = 0.07) value for Breeding Worth than the H sires (H:37; L:46), and there were only small differences in yields of milk or MSY between the two lines when these were expressed per kg of LW, per kg of LW0.75 or per tonne of dry matter required (H: 84 kg MSY/tonne DM; L: 87 kg MSY/tonne DM). The results indicate that the extra MSY by the H cows (+ 16 kg) almost compensated for the effect of their extra LW (+ 46 kg), so that the H cows were only slightly less efficient than the L cows, as predicted by their respective sire{\textquoteright}s Breeding Worth. }, issn = {1176-5283}, author = {Garcia-Muniz JG and Holmes CW and Garrick DJ and Lopez-Villalobos N and Wickham BW and Wilson G and Brookes IM and Purchas RW} } @conference {41057, title = {Growth factors and their role in wool growth: a review}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {303-311}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Wool follicles develop as a consequence of interactions between cells of the epidermis and dermis during intrauterine life. Fibre growth in mature follicles is believed to be governed predominantly by exchanges of signals between these cells and the matrices in which they are embedded. Over the last decade, increasing numbers of growth factors have been implicated in such communications. In particular, these include members of the epidermal growth factor (EGF), fibroblast growth factor (FGF), insulin-like growth factor (IGF), and transforming growth factor-beta (TGF-β) families. Their actions have been shown in studies of skin cells in culture, gene manipulation and physiological experiments with isolated follicles or whole animals. A picture is beginning to emerge of orchestrated morphogenic, mitogenic and differentiative influences between follicle cells, and between cells and their extracellular matrices. When combined with growing technological capability, increases in our understanding of cellular signalling will present novel opportunities for the industry to usefully alter wool growth and fibre characteristics.}, issn = {1176-5283}, author = {Nixon AJ and Moore GPM} } @conference {41008, title = {Herbage intake, grazing behaviour and feed conversion efficiency of lactating Holstein-Friesian cows that differ genetically for liveweight}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {128-131}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Two experiments were carried out to compare the feed conversion efficiency at high pasture allowances in early (EXP1) and mid-lactation (EXP2) of genetically heavy (H) or light (L) Holstein-Friesian cows (H = 487, L = 410 kg, P<0.001). Average milksolids (MS) yield was not significantly different in EXP1 (H = 1.73, L = 1.64 kg MS), but the H line had higher MS yield than the L line in EXP2 (H = 1.70, L = 1.54 kg/cow/day, P<0.001). The mean individual dry matter intakes (DMI, kg/cow/day), measured using the n-alkanes technique, were higher for H cows in both EXP1 (H = 15.5 and L = 13.9; P<0.05) and EXP2 (H = 12.2 and L = 10.8; P<0.05). However, herbage intake was not significantly different between the H and L cows when adjusted to a common MS yield. Feed conversion efficiency (g MS/kg DMI) was slightly higher for the L cows during EXP1 (H = 114, L = 120, P = <0.1), but not different for H and L cows during EXP2 (H = 144, L = 143). The calculated bite size of the H cows was on average 0.095 g DM/bite (pooled for the two experiments) heavier (P<0.05) than that of the L cows, but the L cows showed a consistently faster rate of biting than the H cows (H = 51, L = 56 bites/min, P<0.05). Although the H cows had higher MS yield than the L cows, especially in EXP2, the higher MS yield was not associated with increased efficiency, presumably because the H cows required more energy for maintenance than the L cows. }, issn = {1176-5283}, author = {Laborde D and Garcia-Muniz JG and Holmes CW} } @conference {41028, title = {Iodine deficiency: an emerging problem in New Zealand sheep flocks.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {202-204}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Iodine supplementation before mating had a significant positive effect on ewe fertility in a Manawatu Romney flock, with 14\% more lambs born to supplemented than to control mixed aged ewes. The survival of newborn lambs was enhanced in the iodine-supplemented group when compared with the control group, accompanied by a significant difference between the thyroid:body weight ratios of dead newborn lambs in the supplemented and control groups (0.28 and 0.48 g/kg respectively)(p=0.005). During the spring of 1997, high perinatal lamb mortality rates (25\%, 50\% and 66\%), despite favourable lambing weather conditions and adequate ewe nutrition throughout pregnancy, were investigated in three other Manawatu sheep flocks. The mean lamb thyroid:body weight ratios of dead newborn lambs were greater than 0.4 g/kg and hyperplastic colloid goitre was identified histologically. Goitrogens in the pasture were believed to be an important predisposing factor. Modern varieties of white clover present in New Zealand pastures contain extremely high concentrations of thiocyanate goitrogen precursors, therefore, iodine deficiency may be an emerging problem. }, issn = {1176-5283}, author = {Sargison ND and West DM} } @conference {41009, title = {Management decision rules to optimise milksolids production on dairy farms}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {132-135}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A review of grazing management research has provided a series of decision rules for the management of seasonal calving pastoral dairy farm systems. These rules have been used at the DRC No. 2 Dairy to remove subjectivity from the management of farm systems research. Cows are dried off with sufficient time for second calvers and mixed age cows to achieve condition scores of 5 and 4.5 by 1 June. Target pasture average herbage mass at calving is 2200 kg DM/ha. Optimum grazing management during autumn/winter, spring and summer has been shown to increase milksolids production by 29, 70 and 41 kg MS/ha, respectively. Grazing management during late spring must meet the dual objectives of generously feeding the herd, while maintaining pasture quality. Conserved pasture supplements should be fed in late autumn/early winter to meet cow condition, grazing management, and herbage mass objectives. Substantial increases in animal productivity can be achieved by sound farm management during periods of feed deficit. }, issn = {1176-5283}, author = {MacDonald KA and Penno JW} } @conference {40995, title = {Manipulating patterns of ovarian follicle development in cattle with progesterone and gonadotrophin releasing hormone to produce oestrous cycles with two or three follicle waves}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {85-87}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {This study tested the hypothesis that oestrous cycles with two follicle waves created using progesterone, could be converted to oestrous cycles with three follicle waves using gonadotrophin releasing hormone (GnRH). Oestrus (Day 0) was synchronised in 24 Friesian cows. On Day 2, a progesterone containing device (CIDR) was inserted into the vagina of 16 cows for 10 days. Eight of these animals received 8{\textmu}g of buserelin (GnRH) at device removal. Eight untreated animals formed the Control group. Daily transrectal ultrasonography showed that the oestrous cycles of the cows treated only with a CIDR device had two ovarian follicle waves compared to 1/8 in CIDR+GnRH and 3/8 in Control groups (p<0.01). The average length of the oestrous cycle was shorter in the CIDR-only group (19.3 {\textpm} 0.5 days), compared to the CIDR+GnRH (20.9 {\textpm} 0.2 days) and Control (22.3 {\textpm} 1.1 days) groups (p<0.05). These results demonstrate that strategic administration of GnRH can convert progesterone induced two-wave oestrous cycles into a three-wave pattern. }, issn = {1176-5283}, author = {Clark BA and Rhodes FM and Burke CR and Morgan SR and Macmillan KL} } @conference {41052, title = {Mature Merino ewe production performance in an ultrafine fibre diameter selected and a control flock}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {284-287}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Mature Merino ewe data (1988 to 1995) from 1407 ultrafine (UF) fibre diameter selected and 249 random controls (CF) totalling 3213 and 765 records respectively were analysed. Mean fibre diameter (FD) was significantly (P<0.001) lower in UF compared with CF (17.7 mm vs. 20.0 SED 0.04). Mean FD decreased in UF adult ewes by 0.16 um ({\textpm}0.02) per year relative to CF. There were no differences for autumn live weight but UF was significantly lower for spring live weight (P<0.05) and fleece weight (P<0.01) and higher for fleece yield (P<0.01) than CF. There were significant (P<0.001) age effects for all of these traits. For those ewes born during the project (1990-1994), the number of lambs born per ewe was slightly higher for CF than UF (1.17 vs. 1.14 SED 0.04) but not significant. CF wool had greater tensile strength, bulk and yellow but lower crimp frequency (all P<0.01) than UF wool. Selection for ultrafine wool in Merino sheep has shown FD was significantly reduced without negative effect on liveweight and reproduction. }, issn = {1176-5283}, author = {Wuliji T and Dodds KG and Andrews RN and Turner PR} } @conference {40999, title = {Milk progesterone concentrations at selected times following oestrus and insemination in relation to the success of pregnancy}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {95-97}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Positive relationships between concentrations of progesterone in milk and subsequent pregnancy rates suggest that measurement of milk progesterone concentration at selected times following insemination may facilitate identification of cows for strategic progesterone supplementation to enhance the probability of pregnancy. This study investigated some factors associated with variation in milk progesterone concentration. Following a standard oestrus synchronisation treatment with CIDR-BTM devices (InterAg, NZ), cloprostenol (Estroplan injection, Parnell Laboratories NZ Ltd, NZ) and oestradiol benzoate (CIDIROL Injection, InterAg, NZ) every cow artificially inseminated (AI) at 72 h after CIDR-BTM withdrawal (Day 0) was enrolled in the trial. Milk samples (fore-milk: Herd 1, n = 153, Holstein-Friesian; HF; composite: Herd 2, n = 50 HF and 76 Jersey; J) were taken 4, 8 and 22 days after AI to measure milk progesterone concentration. Pregnancy to the insemination was confirmed by rectal palpation 60-70 days later. Lower milk progesterone concentrations were found in fore-milk (Herd 1) than composite samples (Herd 2), but followed a similar pattern of change throughout Days 4, 8 and 22. Neither return to service, nor pregnancy status was associated with altered milk progesterone concentration on Days 4 or 8, but levels on Day 22 were higher (P<0.001) in pregnant cows. Mean milk progesterone concentrations were higher (P<0.001) in J than HF in Herd 2 on Day 8. Absolute milk progesterone concentration on Day 4 or 8 following AI did not predict the probability of pregnancy establishment, but the difference between milk progesterone concentration in the two samples was of predictive value on a herd, but not an individual cow, basis. Milk collection methods and breed effects need to be considered when developing milk progesterone concentration as a predictor of pregnancy establishment. Although the non-parametric analyses showed that non-pregnant animals tended to have lower milk progesterone concentration, the requirement for analysis of at least two samples will limit its use as a practical means to identify the subset of cows for which strategic progesterone supplementation might be considered. }, issn = {1176-5283}, author = {Verkerk GA and Macmillan KL} } @conference {41017, title = {Modelling the Feed Requirements of Cross-Bred Sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {161-164}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Feed requirements of flocks of ewes from Romney dams mated to either Romney , Border x Dorset, Finn x Texel, or Texel x Dorset sires (R, BD, FT, TD), were estimated from assumed profiles of live weight and reproductive performance. These were constructed by extrapolating data collected from four flocks of 500 ewes each, born in 1994 and run under a common management system at Limestone Downs (a large Waikato sheep/beef property). Annual feed requirements for R, BD, FT and TD ewes (plus 25\% replacements) were estimated to be : 670, 809, 766 and 740 kg DM/ewe; equivalent ewe numbers for the same annual intake: 1000, 829, 875 and 906 ewes; g lamb weaned/kg DM consumed: 37, 43, 47 and 40 g/kg DM. Live weight and reproductive profiles for ewes sired by East Friesian rams were also constructed by extrapolating data from East Friesian-cross ewes born at Limestone Downs in 1996 and mated as hoggets in 1997. Estimates of annual feed intakes, equivalent ewe numbers and g lamb weaned/kg DM consumed for East Friesian-cross ewes (plus 25\% replacements), mated first as hoggets (EFH) were: 925 kg DM/ewe, 725 ewes and 56g/kg DM; or mated first as two-tooths (EF): 907 kg DM/ewe, 739 ewes, and 50g/kg DM. The increased feed demand for high producing ewes occurred mainly from late pregnancy until weaning. }, issn = {1176-5283}, author = {Brookes IM and Lowe KI and Garrick DJ} } @conference {41034, title = {Monitoring some muscoid fly populations on Massey University sheep farms in the Manawatu}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {220-223}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Over three summers (1993-94, 1996 and 1996-97), four fly-traps were placed at each of two locations on Massey University farms. Caught flies comprised eight species, of which four are commonly involved in flystrike. Australian sheep blowfly (Lucilia cuprina) numbers caught varied dramatically between years. At the season peak, numbers in 1996 and 1996-97 were three and one and a half times higher, respectively, than in the first year. Average weekly fly catch increased rapidly over a 2-3 week period from near zero to a peak (in years 1996 and 1996-97) of about 30 flies for L. cuprina and from near zero to a peak (in 1996-97) of about 75 flies for Chrysomya rufifacies in February/early March. Peaks presumably reflected emergence of adult flies from the previous year{\textquoteright}s pupae that overwintered in the soil. Five of the eight species showed a second peak about four weeks after the first. The second peak most likely reflects emergence of a second generation. Minimum temperature explained a significant proportion of variation (up to 48\%) in fly numbers. Rainfall and wind run were less important. Further work is required to provide robust indicators of potential rises in fly numbers. }, issn = {1176-5283}, author = {Cottam YH and Blair HT and Potter MA} } @conference {41036, title = {New Zealand beef industry structure and opportunities to improve income}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {228-230}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {As a product, beef can be classified as suiting table or processing requirements. The aim of this study is to quantify the volume and value of table and processing beef arising from herds of beef or dairy origin to identify opportunities for increasing industry revenue from improving table beef harvest relative to processing products. A deterministic model was developed to calculate product flows and income from processing and table beef derived from beef and dairy herds over a 20 year horizon. The dairy herd contributed 52\% of beef, 60\% of processing grade beef and 45\% of total beef income. Processing grade beef comprised 58\% of total product by weight. Beef-breed steers and Holstein-Friesian (F) bulls were the largest contributors of any cattle class to table and processing grade beef and total industry revenue. Improving the harvest of table beef by 1\% from F bulls would increase beef industry revenue by 0.7\%, a similar increase in revenue that could be achieved from beef-breed steers. The relative contribution of beef and dairy origin cattle to beef revenue is insensitive to table beef premiums over processing beef. Any improvement strategy within the beef industry should be considered with dairy-origin beef animals in mind. }, issn = {1176-5283}, author = {Charteris PL and Garrick DJ and Morris ST} } @conference {40980, title = {Once-Daily Milking of Dairy Cows : An Appraisal}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {36-40}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Once-daily milking offers the opportunity for a quantum change in the operation of the dairy farm. In particular, once-daily milking provides the major opportunity to reduce costs and increase labour productivity. New Zealand cows (particularly Jerseys) already possess an advantage in favour of once daily milking - that they produce a relatively concentrated milk and therefore have the capacity to accumulate >24 hours-worth of milk production. Nevertheless, short-term trials indicate an average production loss of 21\% for once-daily relative to twice-daily milking. Full-lactation trials suggest greater losses of 35-50\%, although the productivity of commercial farms milking once-daily throughout lactation is consistent with much smaller losses. There is evidence that cows can adapt to longer milking intervals and this coupled with increased herd size and care to maximise milk removal may restrict yield losses on the farm to less than 10\%. Apart from the production loss, other negative consequences of once-daily milking include changes in milk composition, a reduction in milk processing quality and increased somatic cell count. Further, it is not known to what degree, if any, cow comfort is compromised by once-daily milking. If it becomes possible to identify more tolerant breeds or individuals, it may be feasible to reduce milk yield losses still further and ameliorate the changes in milk composition. }, issn = {1176-5283}, author = {Davis SR and Farr VC and Stelwagen K} } @conference {40976, title = {Out-of-season breeding in thyroidectomized red deer hinds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {20-24}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Thyroid hormones are required for the neuroendocrine processes that cause the onset of the non-reproductive state each spring in red deer. To evaluate the feasibility of achieving out-of-season breeding using thyroidectomized (THX) hinds and a THX stag, oestrous behaviour and ovulation were compared in THX (n=9) and thyroid-intact control hinds (n=6) following synchronization of oestrous cycles with CIDRs and joining with a THX, vasectomized stag in the breeding and non-breeding seasons. In the control group, oestrus and ovulation were recorded in all (100\%) and none (0\%) of hinds during May (breeding season) and October (non-breeding season) respectively (P<0.05), however in THX hinds oestrus and ovulation occurred in a proportion of the animals (33-55\%) and this incidence was not affected by season (P>0.05). Time of onset after synchronization and duration of oestrus were not significantly affected by thyroidectomy or season (P>0.05). To determine if pregnancy could be established in THX hinds in the non-breeding season, all 15 hinds were synchronized for oestrus using CIDRs plus 200 I.U. PMSG and joined with a fertile, THX stag in early December. Any hinds not mated on this occasion were resynchronized using CIDRs plus 400 I.U. PMSG and again joined with a fertile, THX stag. While the lower dose of PMSG was generally ineffective in inducing oestrus (i.e. only 2 THX hinds mated), 50\% of control and 71\% of THX hinds which received 400 I.U. PMSG exhibited overt oestrus. In all, seven out-of-season calvings (3 from thyroid intact and 4 from THX hinds) were obtained from 10 matings (all 3 unsuccessful matings occurred in THX hinds). These results imply that although thyroid gland secretions switch off reproductive activity at the end of the breeding season, they do have a supportive role in the expression of overt oestrus and occurrence of ovulation. }, issn = {1176-5283}, author = {Anderson GM and Barrell GK} } @conference {40996, title = {Ovarian volume is a predictor of the resumption of spontaneous oestrous cycles but not the response to the treatment of anoestrus.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {88}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {This study examined the use of a classification system for ovarian activity as a predictor for both the spontaneous resumption of oestrous cycles and for reproductive per-formance after treatment for anoestrus.}, issn = {1176-5283}, author = {Nation DP and Rhodes FM and Day AM and Macmillan KL} } @conference {41037, title = {A participatory evaluation of out-of-season beef cattle finishing systems in the lower North Island.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {231-235}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Beef cattle slaughter in New Zealand continues to be strongly seasonal, despite various initiatives by meat processing companies to alter the pattern of supply of cattle for slaughter. The farmer{\textquoteleft}s perspective of out-of-season (OOS) production systems (August -October supply) and the biological and financial feasibility of these was investigated through a participatory approach to farm system modelling. Three case farms were modelled using STOCKPOL and alternative cattle policies that provided a greater proportion of cattle for slaughter in OOS and shoulder (November - December and June - July) months were investigated with the farmers. Even with premiums 20\% above schedule, farmers were unwillings to change policies to OOS. They were concerned about increased business risk, poorer feed quality, increased pasture pugging, greater workload over the busy lambing/calving period, poorer overall suitability to the property and conflict with personal preference. They were more receptive to policies that would increase shoulder production and this factor combined with off-farm improvements in technology for delivering fresh products to overseas destinations may be sufficient to gain new or greater access to high value markets. }, issn = {1176-5283}, author = {Sherlock TJ and Parker WJ} } @conference {41047, title = {Performance of Romney and One-Quarter Merino x Three-Quarters Romney sheep on Wanganui hill country}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {266-269}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The performance of hoggets of part-superfine-Merino ancestry born in 1994 and 1995 were compared with straightbred Romneys (R) in a highly selected nucleus flock on a hill country property, near Wanganui. All animals were born to R ewes. In addition to R, {\textonehalf} Merinos ({\textonehalf} M) were born in 1993 and {\textonequarter} Merino ({\textonequarter}M) in 1994 and 1995. The {\textonequarter}M and R sheep born in 1994 did not differ significantly in hogget greasy fleece weight, live weights, growth rates, or faecal egg and nematode counts. Midside fleece samples collected at two-tooth ewe shearing in late February 1996 showed that the {\textonequarter}M sheep were finer, more yellow, more-bulky and had shorter wool than the R sheep. For {\textonequarter}M and R sheep born in 1995, the {\textonequarter}M genotype had a lower hogget greasy fleece weight, weaning weight and 12 month live weight. The {\textonequarter}M hogget wool was finer, brighter, less yellow, bulkier and shorter than the R midside wool. Clean scoured yield was not significantly different. }, issn = {1176-5283}, author = {Everett-Hincks JM and Wickham GA and Blair HT} } @conference {40970, title = {Possible impact of New Technologies On Dairy Cattle Breeding}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {1-5}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The aim of this paper is to draw together a variety of existing and emerging technologies and to look at how they interact and how they may impact on genetic improvement.}, issn = {1176-5283}, author = {McClintock AE} } @conference {41045, title = {Pregnancy diagnosis of twinning beef cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {259-261}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Technology now exists to make beef cows twin-pregnant. Accurate detection of pregnancy status is a prerequisite for differential management of twin and single-bearing cows. Calving outcome for about 50 beef cows was compared with predicted outcome by foetal counting using transrectal ultrasonography at day 50-70 of pregnancy, and veterinary palpation to confirm pregnancy at day 111-156. The trial ran for 4 annual calvings, and different combinations of scanning operator and equipment were used in each year. Overall accuracy of prediction of calving outcome ranged from 74-94\%, and did not differ for cows carrying singles or twins. Prediction accuracy was highest in the 2 years where scanning equipment provided a high degree of visual detail, and the operator was experienced in distinguishing foetal abnormalities. It was concluded that the combination of early foetal counting using ultrasound, and later determination of wet/dry status by palpation, could lead to levels of accuracy close to those being achieved by competent commercial scanning operators for sheep. }, issn = {1176-5283}, author = {Lambert MG and Perkins NR and Devantier BP and Knight TW and Betteridge K} } @conference {41015, title = {Preliminary results of selecting sheep for resistance or susceptibility to ryegrass staggers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {154-156}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Ryegrass staggers (RGS) is a neurotoxic disease in ruminants caused by the mycotoxin lolitrem B, found in endophyte-infected swards of perennial ryegrass (Lolium perenne L.). This paper reviews genetic studies on the incidence of RGS at Ruakura, and the early responses to selection achieved since 1993. Using a coarse 0 or 1 criterion only, the incidence of RGS each year was recorded on weaned lambs (born in 1988-92), 2-tooths and all mixed-aged ewes, between January and March of each year 1989-93. Clinical cases of RGS occurred in 17 of 25 contemporary groups, with incidences per group up to 0.16. With 3587 records from 2307 animals representing 232 sires, animal-model restricted maximum likelihood estimates of heritability and across-year repeatability for RGS incidence were 0.068 {\textpm} 0.028 and 0.24 {\textpm} 0.05 respectively. Breeding value data were used to screen ewes and 2-tooths in 1993 into resistant and susceptible selection flocks, and to allocate elite rams for mating. Over the 1993-97 mating years, 14 and 12 rams have been used in the two flocks, respectively (11 of these twice or more). There was no significant effect of gender on incidence of RGS. From the most recent completed recording year (i.e. 1996-born lambs), 82 resistant-flock and 56 susceptible-flock animals had RGS incidences of 0.20 and 0.75 respectively (P<0.001). One hundred and eighty-five first-crosses between the two selection lines were also generated in 1996 and 1997, which may eventually provide more evidence on the mode of inheritance. The selection flocks are being continued. The selection response so far indicates that genetic differences in RGS susceptibility can be achieved while using recording under extensive conditions. }, issn = {1176-5283}, author = {Morris CA and Towers NR and Amyes NC and Wheeler M} } @conference {40992, title = {Prevalence of clinical mastitis in 38 Waikato dairy herds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {76-78}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The apparent prevalence of clinical mastitis was determined in 38 spring calving dairy herds as part of a larger field trial conducted on behalf of Boehringer Ingelheim NZ Ltd between the 8th of July and the 21st of August, 1997. A total of 798 quarters from 595 cows were diagnosed by herdowners as having clinical mastitis. Bacterial culture was performed on all clinical quarters and antibiotic sensitivity testing was performed on selected bacterial isolates. Clinical mastitis was diagnosed in an average of 10.0\% ({\textpm} 0.8\%, range 0.9\% to 21.4\%) of calved cows within the herds. No bacteria were cultured from 28.2\% of clinical quarters. Of the quarters from which bacteria were cultured, 74.7\% were Streptococcus uberis, 10.2\% were coagulase negative staphylococci, 4.7\% were Coliforms, 4.1\% were Streptococcus dysgalactiae, 2.9\% were Staphylococcus aureus and 3.3\% were other species of bacteria. Penicillin resistance was detected in 25\% of 44 Staphylococcus aureus isolates, 0\% of 10 Streptococcus uberis isolates and 100\% of 12 E. coli isolates. }, issn = {1176-5283}, author = {McDougall S} } @conference {41041, title = {Productivity and Profitability of Twinning Beef Cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {245-247}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Twinning Hereford x Friesian beef cows were run in farmlets with breeding ewes at Whatawhata Research Centre. The additional inputs and outputs of twinning cows were compared with those of single calving treatments. This was carried out in a farm systems environment so that the feed-back mechanisms inherent in biological systems could operate. Typically, the twinning beef cows lost 15\% of their foetuses during pregnancy and had (in the most recent year) a calf survival rate of 80\%. Comparable figures for single calving cows were 5 and 95\% respectively. Twin calves weighed 200 kg at weaning compared to 240 kg for singles. The twin cow farmlets required 250 kg extra DM/cow and 5.7 extra hours of labour/cow at calving. The sheep were not measurably affected by cow treatment. Gross margin analyses using these and other trial data indicated that twinning cows were $44/cow less profitable than single cows. Further analyses showed however, that the twinning cow system would breakeven with the singles if any one of the following changes were possible, (1) twin calf wean weight 220kg, (2) twin calf survival 89\%, (3) twin foetal loss 5\%, (4) labour differences dropped from 5.5 (above) to 2.1 hours/cow. When all the breakeven values were assumed to have occurred at the same time, twin cows were $120/cow more profitable than single cows. This is the money available to pay for extra risk and the extra cost of getting a cow twin pregnant (at day 60) compared to single pregnant. }, issn = {1176-5283}, author = {Smeaton DC and Clayton JB} } @conference {41056, title = {Prolactin receptors are highly expressed in wool follicle dermal papillae.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {298-302}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Seasonal variation in wool growth has major impacts on production and fibre characteristics. These changes in wool follicle output are driven, at least in part, by circulating prolactin. We therefore localised prolactin receptors (PRLR) in skin from Wiltshire sheep over a wool follicle cycle induced by prolactin. PRLR expression was visualised by in situ hybridisation, immunocytochemistry and radioligand binding. The three approaches showed concordant distributions of PRLR and its mRNA. PRLR mRNA was most abundant in the dermal papilla, but also evident in the outer root sheath, hair germ, skin glands and epidermis. Expression in the hair germ was up-regulated in telogen. Location of PRLR in the dermal papilla and outer root sheath indicates action of prolactin directly on the growth controlling cells within wool follicles. These spatial and cycle-related patterns of PRLR expression contribute to the growing knowledge of the control of wool growth and its application in the wool industry. }, issn = {1176-5283}, author = {Nixon AJ and Choy VJ and Ford CA and Pearson AJ} } @conference {40983, title = {Rates of recovery of milk yield and composition following milking intervals of varying length}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {47-48}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {In order to examine the rate of recovery of milk yield and composition following an extended milking interval, 20 cows were milked out with the aid of oxytocin and subjected to single intervals of either 16, 24, 32 or 40h. Cows were then milked frequently with the aid of oxytocin during the subsequent 26h. Milk secretion rate was depressed to 67 and 56\% of pre-treatment (twice-daily milking) rates by the 32 and 40h treatments, and rates of recovery were slow, extending beyond 26h post-treatment. Milk fat and protein contents did not differ significantly among treatment groups while lactose content was reduced by the 32 and 40h intervals, recovering by 26h post-treatment. It was concluded that the udder is particularly sensitive to milk accumulation beyond 24h and that this leads to impairment of the {\textquoteleft}synthetic machinery{\textquoteright} in the udder. The prolonged effect on milk lactose concentrations with the longer intervals suggests that there was a sustained change in the integrity of tight junctions between secretory cells, leading to increased permeability of the mammary gland. Rates of recovery of yield and composition were relatively slow, taking >24h in spite of enhanced rates of milk removal. }, issn = {1176-5283}, author = {Farr VC and Stelwagen K and Davis SR} } @conference {40974, title = {Recent improvements in flow cytometric sorting efficiency of X and Y-chromosome bearing sperm of domestic animals: a review.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {16-18}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {In mammals the only method known to reliably separate X and Y sperm for producing offspring of a specific sex is flow cytometric sorting. This method is based on the observation that X-chromosome bearing sperm of domestic animals contain 3.5-4.2\% more DNA than Y-chromosome bearing sperm. Relative DNA content is determined by quantitative staining with Hoechst 33342 and DNA content measured using a modified cell sorter. The major constraint to widespread application of this technology has been the slow sorting rate. Using modified standard speed cell sorters, sample flow rates average 2,000 sperm/sec with 25-35\% orientation. Recently, a high speed sorter (MoFlo{\textregistered}) modified for sperm sorting has been used and increases sorting rate by approximately 5-fold. Further, an orienting nozzle has been developed which increases the percentage of sperm that are orientated thus increasing the sort rate by a further 2 to 3-fold. Combined, these improvements have increased the production of sorted sperm from approximately 0.3 x 106/h with conventional sorters to at least 4 x 106/h with the high speed sorter. Preliminary testing suggests that purity of sort and sperm viability are not compromised by increased sorting rates. Pregnancies have been established in pigs and cows with sorted sperm from a modified MoFlo fitted with a novel nozzle. The improvements outlined here greatly enhance the Beltsville Sperm Sexing Technology and make it realistic to consider trials using sex sorted sperm for conventional AI as well as deep uterine AI in cattle. }, issn = {1176-5283}, author = {Gurnsey MP and Johnson LA} } @conference {41044, title = {The relationship between carotenoid concentration and fat colour in beef carcasses}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {256-258}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Relationships between carotenoid concentration, chromameter (L* a* b*), and subjective measurements of fat colour were calculated from 15 mobs of cattle. Carotenoid concentration accounted for 60\% of the variation in b* (n=514), but b* accounted for only 16\% of the variation in subjectively measured fat colour (n=732). Neither the inclusion of other variables (e.g. carcass weight or fat depth) nor transformation of the data substantially improved these relationships. }, issn = {1176-5283}, author = {Knight TW and Death AF and Boom CJ and Litherland AJ} } @conference {41022, title = {Relationships between laboratory measures of ram sperm competence and field fertility.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {181-185}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Previous work has show poor relationships between the maintenance of sperm motility and fertility after AI of ram semen. New laboratory tests of sperm competence have been developed but their relationship to fertility needs to be established. Two large scale trials involving the laboratory evaluation of straws of frozen semen from different rams and the field AI of ewes with the same batches of semen were conducted. In Trial A, 1671 ewes were AI{\textquoteleft}d with 52 batches of semen from 26 rams on 6 farms. In Trial B 6872 ewes were AI{\textquoteleft}d with 137 batches of semen from 34 rams on 25 farms. In Trial A, there was no linkage between farms while in Trial B the same batch was used on more than one farm and most farms had more than 1 batch from more than 1 ram. Laboratory evaluation involved: visual motility assessment post thaw and time taken to drop to 5\% motility when incubated at 38{\textdegree}C, 8 parameters of velocity and direction of motility using CASA; \% live and \% acrosome intact and sperm concentration. These parameters were measured immediately post-thaw and in Trial B a repeat measurement was made after 6h at 38{\textdegree}C. In addition, in Trial A the relative IVF value was determined. In Trial A there were significant (P<0.05) between farm and ram within farm effects on fertility (\% pregnant) but no ejaculate within ram effect. Significant (P<0.001) differences were seen in all semen parameters except initial motility, time to 5\% and concentration. Parameters correlated with fertility were IVF and \% live and together these accounted for 44 \% of the variation. In Trial B, there were effects of farm on fertility (P<0.001) and breed of ram (P<0.05), residual ram variation was non-zero but not significant. There were significant differences between rams and between ejaculates within rams in concentration, visual motility, \% live, velocity and directional parameters. The number of live and motile sperm inseminated was correlated (P<0.001) with fertility. Significant (P<0.05) correlations were also obtained between two CASA parameters; the \% live and \% visual motility, after 6h of incubation. Multiple regression equations were derived that accounted for between 62 and 75 \% of the variation between rams. }, issn = {1176-5283}, author = {Smith JF and Parr J and Murray GR and Clarke A and McDonald RM and Duganzich DM} } @conference {40991, title = {Reproductive performance of Holstein-Friesian cows differing genetically in live weight}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {73-75}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The reproductive performance of two genetic lines of Holstein-Friesian cows bred for heavy (H) or light (L) mature live weight (LW) was evaluated from 1992 to 1997. The interval calving to ovulation was shorter (P<0.05) for H cows (28 {\textpm} 3.2 days) than for L cows (L: 31 {\textpm} 2.5 days), but the difference between the lines in the interval calving-first heat was not significant (H: 50 days; L: 43 days). However, in the cows older than 2 years old, the H cows had a lower conception rate at first service than the L cows (H: 58\% vs. L: 70\%) which extended the conception and calving pattern of the H cows. The possible reasons for those differences in the reproductive performance are discussed as topics for further research. }, issn = {1176-5283}, author = {Laborde D and Holmes CW and Garcia-Muniz JG and Wichtel J} } @conference {40978, title = {Reticular Groove Contraction in Yearling Cattle Detected by Breath Test}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {29-31}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A novel method was used to detect the incidence of reticular groove contraction in yearling cattle. Following its oral administration, 13C octanoic acid is absorbed from the intestine, metabolised by the liver and the 13C label excreted in the CO2 of breath. Contraction of the reticular groove should result in a quicker and greater peak appearance of 13C in breath, than when swallowed material is delivered into the reticulo-rumen. Mean breath 13 C enrichment after drenching with NaCl was greater (P<0.001) than with water. Mean increases in enrichment after sucking molasses and label were greater than drenching with water (P<0.001) and NaCl (P<0.05). These results are consistent with sodium and sucking stimulating reticular groove contraction and support the use of this method as a simple, repeatable, non-radioactive and non-invasive means of detecting the route taken of orally administered therapeutic agents or nutrients. The test, for example, would identify those animals at risk by rumen bypass of anti-bloat agents. }, issn = {1176-5283}, author = {McLeay LM and Carruthers VR and Neil PG} } @conference {41014, title = {The role of cysteine in the increased parasite susceptibility of Romney sheep selected for hogget fleece-weight.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {150-153}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {To investigate the potential role of cysteine in the increased parasite susceptibility of sheep selected for increased wool production, ten sheep from both fleece-weight-selected (FW) and randomly-selected (C) Romney lines received either 2g of supplemental cysteine per day, or saline, via abomasal infusion. Following drenching to remove any pre-existing parasites, all sheep were dosed with Haemonchus contortus and Trichostrongylus colubriformis infective larvae. Cysteine infusion elevated plasma cysteine levels by an average of 65\% (P<0.0001). Off-pasture faecal egg counts (FEC) were higher in FW than C sheep (645 versus 200 eggs/g, P<0.01). No significant effects of line or infusion treatment on FEC were observed following the trial infection, though on days 52, 57 and 58, FEC in sheep receiving saline were at least twice those of sheep receiving cysteine. Total H. contortus counts were greater in FW than C lines of sheep (1208 versus 1055, P<0.05), while total numbers of T. colubriformis did not differ between lines or infusions. This study confirms the greater susceptibility of FW sheep to internal parasites, and suggests cysteine may influence certain aspects of immunocompetency in sheep. }, issn = {1176-5283}, author = {Miller FM and Blair HT and Reynolds GW and Revell DK} } @conference {41019, title = {The role of milk production in dryland lamb production systems}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {170-174}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A farmlet study was carried out over 2 years to examine the role of milk production in dryland lamb production systems. Poll Dorset and Romney ewes were used to represent high and low levels of milk production and mated to produce reciprocal cross lambs. High and low fecundity treatments were included in replicated farmlets of 2.9 ha and stocked at 15 ewes/ha. Mean lambing dates were 5th and 8th August with lambs drafted for slaughter from mid October. In Year 1, Poll Dorset ewes produced 44\% (singles) and 88\% (twins) more milk in peak lactation than their Romney counterparts. In late lactation, Poll Dorsets produced 41\% (singles) and 169\% (twins) more milk. In Year 2, the advantages were 19\% (singles) and 18\% (twins) in peak lactation and 78\% (singles) and 67\% (twins) in late lactation. Increased milk production had small effects on lamb growth rates in the low fecundity treatments (Year 1: 338 vs 328 g/d; Year 2: 317 vs 300 g/d for the respective high and low milk treatments). In the high fecundity farmlets, dam breed differences were larger (Year 1 :280 vs 244g/d ; Year 2: 307 vs 283 g/d, respectively). Number of lambs drafted by the 2nd December were also similar in low fecundity groups (Year 1: 93\% vs 95\%; Year 2: 90\% vs 93\%, respectively). Greater numbers of lambs were drafted off high fecundity Poll Dorsets than Romney dams (56\% vs 23\%) in Year 1 but not in Year 2 (85\% vs 81\%). The greater effect of milk on lamb growth in high fecundity treatments in Year 1 was attributed to poor spring feed conditions and the buffering ability of high milk producing ewes. }, issn = {1176-5283}, author = {Muir PD and Wallace GJ and McCall DG and Dodd CJ} } @conference {41002, title = {Ruminal utilisation of pasture nitrogen in response to increased level of dietary starch inclusion}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {106-109}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Four diets based on high quality pasture were formulated using additions of starch to contain 12.8, 19.6, 26.3, or 33\% total nonstructural carbohydrate and were evaluated using four continuous culture fermenters during four 10 day periods. The true ruminal digestibility of organic matter was not changed by diet but the digestibility of neutral detergent fibre and crude protein linearly decreased, and the digestibility of total nonstructural carbohydrate linearly increased, as the level of starch inclusion increased. Production of NH3 N was reduced linearly from 35.2 to 14.2 mg/dl (P<0.001) and the flow of non-NH3 N as a proportion of total N flow increased linearly from 66\% to 83\% (P<0.001) as inclusion of starch increased. The quantity of microbial N and non-NH3 N flowing from continuous culture was unchanged. The experiment indicated that if the amount of organic matter digested is not appreciably increased by the inclusion of nonstructural carbohydrate then the linear increase in ruminal utilisation of pasture N arises more from a reduced pasture N intake than an improvement in microbial protein synthesis.}, issn = {1176-5283}, author = {Kolver ES and Muller LD and Varga GA} } @conference {40977, title = {Sampling strategy for estimating dairy-pasture quality}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {25-28}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Rapid determination of pasture quality using near infrared reflectance spectroscopy (NIRS) makes it feasible for farmers to incorporate forage composition in feed budgeting and feed supplementation decisions for grazing animals. In grazed pastures, heterogeneity in the distribution of the mass and quality, necessitates a sampling strategy to accurately predict the diet. A single paddock was systematically sampled by selecting 60 sites according to a pre-determined grid. At 12 of these sites, 4 separate but adjacent samples of 150 x 150 mm were taken from within a 300 x 300 mm quadrat. To characterise vertical heterogeneity, the herbage at each of the 60 sites was cut sequentially into 4 equal strata, the depth of each being one-quarter of the canopy surface height at that site. These samples were used to derive a statistically-based 3-dimensional characterisation of variability of herbage mass and of several parameters of herbage quality determined using NIRS. This description was used to calculate the number of samples necessary to estimate parameters to arbitary, pre-determined levels of accuracy of {\textpm} 50 kg DM/ha for herbage mass in each stratum, {\textpm} 50 g/kg protein (PROT), acid detergent and neutral detergent fibre (ADF; NDF), {\textpm} 20 g/kg for soluble carbohydrate (CARB), {\textpm} 25 g/kg for in-vitro dry matter digestibility (DIG) and {\textpm} 0.5 MJ/kg for metabolizable energy (ME). A minimum of six samples bulked together is necessary to estimate PROT, CARB, NDF and ADF to the specified level of accuracy, and this number was similar for each stratum. Twelve samples are required to estimate ME and DIG for each of the 3 upper strata, but in the lowest stratum with greater variability, 48 and 19 samples would be required for ME and DIG, respectively, to reach the same accuracy. A sampling strategy should take the suggested number of samples by systematically covering the paddock area. Uncertainty in the depth of sampling because of the necessity to sample before grazing has little effect on the number of samples required or on the accuracy of estimates, providing the lowest stratum is not penetrated during either sampling or grazing.}, issn = {1176-5283}, author = {Cosgrove GP and Betteridge K and Thomas VJ and Corson DC} } @conference {41048, title = {Seasonality of wool growth in Waikato and Southland of Romney sheep selected for high fleece weight}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {270-273}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Wool growth rate was estimated for a total of 525 Romney ewes born in 1991 and 1992 between 5 and 28 months of age. Both year born groups contained sheep from three flocks selected over an extended period for increased hogget fleece weight and their respective Control flock. One flock was located in the Waikato, one in Southland and one split between the two locations. Following adjustment for live weight the seasonality of wool growth rate in Southland was significantly greater than in the Waikato reflecting the sensitivity of Romney sheep in recognising small changes in the length of daylight between the two locations. Selection for increased hogget fleece weight resulted in a greater increase in relative wool growth rate during the winter than during the summer. }, issn = {1176-5283}, author = {Sumner RMW and Wuliji T and Dobbie JL and Andrews RN and Upsdell MP} } @conference {41018, title = {Sheep breeding: an enterprise budgeting decision support model for on-farm planning.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {165-169}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {In selecting a sheep breeding strategy farmers need to evaluate the likely physical and financial outcomes relative to continuing the existing policy. The strategy should be assessed in terms of the new status quo production levels and costs and prices at this time, and the possible associated effect of changes in product attributes relative to market requirements. To assist farmers evaluate alternative breeding scenarios a spreadsheet-based enterprise budgeting model was developed. The input data and output are summarised to a one-page template to allow the user to assess the sensitivity of returns to different market and production scenarios for a particular farm situation. A flock at current performance levels and those in 5 years, following genetic and management improvement, is compared to a crossbreeding strategy to illustrate the model{\textquoteright}s application. }, issn = {1176-5283}, author = {Parker WJ and Dooley AE and Garrick DJ} } @conference {40973, title = {A simplified method for typing DRB alleles in deer}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {13-15}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Major histocompatibility complex (MHC) genes present foreign antigens to the immune system and polymorphism in these genes may have a key role in the variability of the host response to pathogenic challenge. The DRB genes are part of the MHC class II family whose proteins present foreign antigenic peptides on the surface of the macrophage for recognition by the CD4+T cells of the immune response. The genes are highly variable with over 100 different variants found in some species. The goal of this study was the development and testing of a simplified system for differentiating between the different DRB alleles already identified in red deer. The typing method chosen used DNA hybridisation to discriminate between the DRB alleles. The RNA from each deer was extracted from cultured leukocytes. Reverse transcription followed by PCR was used to amplify the DRB region. Amino-linked oligonucleotides representing variable regions of the DRB region were covalently bound to a nylon membrane and probed with end-labelled PCR product. The degree of binding of the labelled PCR products to the membrane-bound oligonucleotides was used to discriminate between the different DRB genes amplified. This proved to be a simple and robust method of typing which eliminated any requirement for electrophoresis. }, issn = {1176-5283}, author = {Linscott EM and Mackintosh CM and Griffin JFT and Crawford AM} } @conference {40998, title = {Some Effects of Using Progesterone and Gonadotrophin Releasing Hormone on the Reproductive Performance of Inseminated Cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {92-94}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The administration of progesterone (P4) within 3 days following insemination can reduce pregnancy rates. In contrast, an injection of gonadotrophin releasing hormone (GnRH) at about 12 or 13 days after insemination can increase them by around 10\%. This field trial tested the hypothesis that the negative effects reported for the P4 treatment on fertility could be eliminated by strategically injecting GnRH to convert the two ovarian follicle waves per cycle created by using P4, into three wave ones, with increased fertility. A total of 830 cows in 13 dairy herds received comparative treatments involving: (i) the insertion of a P4 intravaginal device 2 or 3 days after first insemination (1st insem.) for 10 days, with an injection of 10 mg of GnRH at device removal (P4 + GnRH); (ii) the same GnRH treatment but without P4 pre-treatment (GnRH); and, (iii) no post-insemination intervention (Control). Pregnancy status and conception date were confirmed by rectal palpation of uterine contents Calving data were recovered from 10 herds to monitor gestation length, dystocia and calf birth weight. The conception rates to 1st insem. were highest for the 255 cows treated with GnRH (64\%; p = 0.05), but similar in the other two groups of 273 and 302 cows (57\%). Second insemination results were not affected by the treatments; neither were final pregnancy rates. Birth weights were higher for bull than heifer calves (36.9 vs 33.0kg; p<0.01), but were not affected by treatment. The results of this trial showed that the P4 + GnRH treatment did have normal fertility and that GnRH injected 12 or 13 days after first insemination could increase conception rates. }, issn = {1176-5283}, author = {Taufa VK and Macmillan KL and Day AM and Ashcroft MJ and Morgan S} } @conference {40975, title = {Techniques for extraction of proteins for enzymatic measurements from ram spermatozoa and sheep muscle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {19}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A method for the preparation of enzyme active representative homogenates of muscle is described. This method was also valuated for spermatozoa and it was observed that the protocol needs to be adapted for various tissue types.}, issn = {1176-5283}, author = {Upreti GC and Oliver JE and Clarke AG and Clarke JN and Smith JF} } @conference {41035, title = {To shear or not to shear lambs?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {224-227}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Poll Dorset x Romney cross lambs (n = 80) were allocated according to sex (ewe, ram) and liveweight to either shorn or unshorn treatments. Pelts were recovered at slaughter, processed to dyed crust leather and scored for visual traits. At the pickled pelt stage, shorn lambs exhibited lower grain strain scores in the main panel (2.4 vs 4.3, P = 0.01). Rib score (2.3 vs 1.9, P = 0.014) was greater for shorn lambs. The fat score of ewe skins was higher (2.6 vs 1.9, P<0.001) and they produced thicker leathers (0.85 vs 0.79 mm, P = 0.025) with more delamination (2.6 vs 2.2, P = 0.004). While shearing risks scarring the pelt, there are trade-offs with other faults in the pelts of shorn or unshorn lambs. The decision on whether to shear lambs or not should be based on the relative costs of the faults. }, issn = {1176-5283}, author = {Scobie DR and Bray AR and Cooper SM} } @conference {41049, title = {Unravelling the causes of wool yellowing: Part I Involvement of a water soluble component}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {274-276}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The change in yellowness (D Y-Z) of wool samples maintained in an environment intended to stimulate yellow discolouration was determined in two experiments. In the first experiment, DY-Z was determined following one of six treatments - no extraction (control), solvent wax extraction (-W), aqueous suint extraction (-S), extraction of wax and suint (-WS), removal then reapplication of wax and suint (+WS), or detergent washing (D). Removal and reapplication of wax and suint, or removal of wax alone resulted in similar yellowing to the control (D Y-Z mean{\textpm}SD); (control 1.6{\textpm}1.2; +WS 1.5{\textpm}2.8, p = 0.92; -W 2.1{\textpm}1.3, p = 0.37). Detergent scouring, and removal of suint, or both wax and suint, reduced wool yellowing (D 0.6{\textpm}2.2, p = 0.24; -S 0.5{\textpm}1.6, p = 0.09; -WS 0.3{\textpm}1.3, p = 0.04). In the second experiment, greasy wool from two chimaeric sheep producing both Lincoln and Merino wool types yellowed to a similar extent (Y-Z post challenge; mean{\textpm}SD) (Lincoln 7.3{\textpm}1.5; Merino 6.5{\textpm}1.1; p = 0.45), suggesting that the fleece environment influences the propensity for yellow discolouration when distinct wool types are grown together. The data presented here support the hypothesis that a water soluble component of the fleece is involved in wool yellowing. }, issn = {1176-5283}, author = {Winder L and Rea A and Scobie D and Bray A} } @conference {41050, title = {Unravelling the causes of wool yellowing: Part II Involvement of bacteria}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {277-280}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Wool was collected from five sheep with a propensity for wool yellowing. Sub-samples, from which the wool tip had been removed, were cut into 2cm lengths and incubated at 40{\textdegree}C for 6 days to provide an environment conducive to wool yellowing (YCT).Five treatments were applied to sub-samples of each fleece prior to YCT. Four sub-samples were gamma irradiated in an attempt to kill all bacteria present on the fleece (-B), the remaining subsample was not irradiated. Two -B sub-samples were re-inoculated with bacteria collected from the original fleece samples (+B). Each of the +B and -B samples was then either incubated at 0\% humidity (-H) or 100\% humidity (+H) for the YCT. Wool yellowness (Y-Z) was measured before and after YCT using standard methods. No relationship was apparent between the number of bacterial colonies in the original fleece (plated onto nutrient agar), and the pre-YCT Y-Z (R2=0.20; P=0.06), Y-Z after the YCT (R2=0.19; P=0.06), or the change in wool Y-Z during the YCT (R2=0.07; P=0.27). Gamma irradiation eliminated bacteria from the wool samples but increased their Y-Z pre-YCT (mean {\textpm} S.D, non-irradiated 2.46{\textpm}0.55; irradiated 4.35{\textpm}0.43; P<0.001). Discolouration of wool (Y-Z) was increased by humidity during YCT (-H 1.06{\textpm}0.45, +H 4.96{\textpm}1.46; P<0.001). At 100\% humidity, reinoculation with bacteria increased wool Y-Z during YCT (+B 6.13{\textpm}0.87; -B 3.78{\textpm}0.75; P<0.01). This effect of reinoculation was lost at 0\% humidity. The interaction between humidity and reinoculation was significant (P<0.05). This study supports the hypothesis that bacteria are involved in the yellow discolouration of wool in the presence of high humidity.}, issn = {1176-5283}, author = {Winder L and Baronian K and Webber J and Muller B} } @conference {41006, title = {Use of {\textquoteright}Barkant{\textquoteright} turnips and {\textquoteright}Superchow{\textquoteright} sorghum crops to increase summer-autumn milk production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {121-124}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {{\textquoteleft}Barkant{\textquoteleft} turnips and {\textquoteleft}Superchow{\textquoteleft} sorghum were compared as summer-autumn crops for lactating cows. Crops were fed at three levels (0, 4 and 8 kg DM/cow/d) to supplement pasture offered at a constant allowance. Sixty twin cows were used in two experimental periods in February and March 1997. Feeding 4 or 8 kg DM/cow/day increased milksolids (MS) yield/cow by 29\% or 36\% for turnips, and 26\% or 32\% for sorghum compared with pasture alone. Turnips gave responses of 58g and 45g MS/kg DM offered, at the lower allowance, in summer and autumn respectively, compared with 45g MS/kg DM in both seasons for sorghum. For both crops, increasing allowance from 4 to 8 kg further increased MS yield. Crop utilisation was lower on sorghum than turnips but substitution rates for turnips were higher than for sorghum at both allowances in both summer and autumn. This means that although both crops have a {\textquoteleft}pasture sparing{\textquoteleft} effect, sorghum contributed more to increased per cow intake. }, issn = {1176-5283}, author = {Harris SL and Clark DA and Waugh CD and Copeman PJA and Napper AR} } @conference {40982, title = {Use of once daily milking compared with treatment with progesterone and oestradiol benzoate (ODB) in anoestrous cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {44-46}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The aim of this study was to compare the rate of resumption of oestrous cycles and fertility to first insemination of anoestrous cows examined 7 days before the planned start of mating (PSM), which were milked once (OAD) or twice daily (TAD) for at least 28 days and untreated or treated with progesterone and oestradiol benzoate (ODB; CIDR). By 28 days after the start of treatment, oestrus was detected in 65.8\%, 76.6\%, 93.5\% and 97.9\% of cows (TAD, OAD, TAD+CIDR and OAD+CIDR, respectively) (p<0.001). Conception rates to first insemination were lower in CIDR treated than untreated cows (40.4\% vs 50.3\%; p<0.05), but were not affected by milking frequency. The mean ({\textpm} sem) interval from PSM to conception was shorter in CIDR treated than untreated cows (12.8 {\textpm} 1.2 vs 19.0 {\textpm} 1.3 days; p<0.001). Daily milk yield decreased by 6.1 {\textpm} 0.2 and 2.2 {\textpm} 0.2 litres; and milk solids by 0.46 {\textpm} 0.02 and 0.19 {\textpm} 0.02 kg (p<0.001) in cows milked OAD and TAD, respectively, over the treatment period. Once daily milking increased the rate of spontaneous resumption of oestrous cycles in anoestrous cows compared with TAD, but was associated with a significant decrease in milk production. Compared to treatment with progesterone and ODB, OAD resulted in a longer interval from PSM to conception. }, issn = {1176-5283}, author = {Rhodes FM and Clark BA and Macmillan KL and McDougall S} } @conference {41005, title = {Using nitrogen fertiliser to increase dairy farm profitability}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {117-120}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Five farmlets were established to investigate the profitability of using nitrogen fertiliser (N) to increase pasture supply and milksolids production. Farmlets were stocked with 3.34 (low) or 4.42 (high) Friesian cows/ha and received 0, 200 or 400 kg N/ha/year. Total annual pasture production was increased by 1.76 and 0.97 t DM/ha when 200 kg N/ha was applied and by 3.2 and 3.6 t DM/ha using 400 kg N/ha at the low and high stocking rate, respectively. Annual milksolids production increased by 142 and 218 kg MS/ha after the application of 200 and 400 kg N/ha, respectively. Increasing stocking rate from 3.34 to 4.42 cows/ha reduced milksolids production by 99 kg MS/cow. Applying 200 kg N/ha at the lower stocking rate increased economic farm surplus by $148/ha. Increasing stocking rate reduced total milksolids production and profitability at both rates of N. }, issn = {1176-5283}, author = {McGrath JM and Penno JW and MacDonald KA and Carter WA} } @conference {40986, title = {The value of monozygotic twins in milk composition experiments.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {55}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Monozygotic (identical) twins have for many years been used to increase the statistical power of experiments in a range of scientific disciplines (Dick and Whittle,1951). In dairy cows, variation within identical twinsets for a given biological parameter is usually substantially less than the variation between unrelated cows or between fraternal twinsets (Hancock 1953; Brumby and Hancock, 1956). Thus the number of identical twins required in an experiment is often considerably less than the number of unrelated cows necessary to achieve the same statistical precision. The experiments described here were conducted to quantify the twin efficiency values of a range of milk composition parameters.}, issn = {1176-5283}, author = {Auldist MJ and Mackle TR and Hooper RJ and Henderson HV} } @conference {41026, title = {Variation in copper metabolism between two flocks of Romney sheep in response to increasing dietary intake of copper}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {195-198}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Differences in the Cu status of two flocks of Romney lambs were observed which suggest that lines of sheep having distinct Cu metabolism have been identified. As part of a larger study relating Cu intake to Cu status of grazing lambs, changes in concentrations of Cu in liver, plasma and other tissues, and in erythrocyte Cu/Zn superoxide dismutase (SOD) were monitored for 176 days in two flocks of 50 sheep. The animals grazed on ten experimental paddocks treated with 0, 0.4 or 4 kg Cu/ha which resulted in mean pasture herbage Cu concentrations of 8 (Control), 13 (Low), and 41 (High) mg Cu/kg DM. At the start of the experiment these lambs, sourced from two Wairoa farms, had markedly different liver Cu reserves (1270 v 190 mmol Cu/kg FW, flocks H and L respectively) which could not be attributed to Cu supplementation. This difference between flocks was maintained throughout the 176 day study for sheep grazed on control pastures, through day 99 for sheep on the low pastures, and for 51 days in sheep on the high paddocks. High copper intakes increased liver Cu concentrations to as much as 4800 mmol (300 mg) Cu/kg liver FW after 99 days, with no signs of chronic Cu toxicity. Initial flock differences in liver Mo concentration (14.7 v 20.6 mmol Mo/kg FW, n=10, P<0.05) disappeared by day 51. The first measured SOD activity (day 51) in flock H was 17\% greater than that of flock L (1600 v 1370 U/g Hb, n=21, P<0.01) and this flock difference was maintained through day 142 and day 99 for sheep grazing control and low pastures, respectively. SOD activity was found to be a reasonable predictor of liver Cu stores only in sheep having low to moderate Cu intake. Had the differences in initial liver Cu concentration and in blood Cu/Zn SOD activity of the two flocks been merely a reflection of the Cu and Mo status of their respective Wairoa farms, the disparity would have been expected to diminish much more quickly than was observed in this study. Factors controlling Cu metabolism are heritable. Trials selecting for differences between flocks in liver Cu concentration are needed to establish whether these flocks are genetically distinct in the way they metabolise Cu. }, issn = {1176-5283}, author = {Knowles SO and Rounce JR and Grace ND and Lee J} } @conference {40985, title = {Variation in milk whey composition throughout lactation in cows of different Beta-lactoglobulin phenotypes.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {52-54}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The association between b-lactoglobulin (β-LG) variants and milk composition throughout lactation was determined by sampling from 44 Friesian cows (22 homozygous for b-LG AA and 22 homozygous for b-LG BB) in early (day 6 postpartum), established (1-3 months postpartum) and late lactation (on the day of drying off). Results indicated that differences between β-LG AA and BB phenotype milk (expressed as a percentage of the level in phenotype AA) in concentrations of bovine serum albumin (BSA; -15.9\%, -32.0\%, -42.5\%) and b-LG (5.9\%, 16.0\%, 32.2\%), in early, established and late lactation respectively, increased steadily as lactation progressed. The differences in a-lactalbumin concentrations were less variable (1.2\%, -9.0\%, -9.1\%). These results provide new evidence that compositional differences are not seen between b-LG AA and BB phenotype milk until established lactation.}, issn = {1176-5283}, author = {Turner S-A and Auldist MJ and Molan PC and Prosser CG} } @conference {41053, title = {Wool fibre diameter effects on yarn bulk independent of core bulk}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {288-290}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The curvature and diameter of fibres influence the core bulk of raw wool, which in turn is used as an indicator of yarn bulk. The compressional properties of fibre masses are difficult to predict from first principles, therefore the direct effect of fibre diameter and curvature on the bulk of semi-worsted yarn was investigated. Wools with similar core bulk (28 cm{\textthreesuperior}/g) in which fibre diameter ranged from 18.5 to 40 mm were processed into semi-worsted yarn and measured for yarn bulk. Contrary to popular belief, fine wool of the same core bulk produced yarn with higher bulk than stronger wool. However, with a correlation coefficient of -0.9 between mean fibre diameter and mean fibre curvature the influence of these two attributes on yarn bulk cannot be separated. Closer examination of the data shows that for these wools, which were selected to have constant core bulk, the variation in yarn bulk can be predicted slightly more accurately by the variation in mean diameter than the variation in mean fibre curvature between the samples. Rather low R{\texttwosuperior} values and the size of the coefficients in the regression equations indicate that the influence either fibre diameter or fibre curvature has on yarn bulk at 28 cm{\textthreesuperior}/g core bulk is small. Wool type also had little effect on the relationship between core bulk and yarn bulk at this level of core bulk. }, issn = {1176-5283}, author = {Maddever D and Bray A} } @conference {41046, title = {Wool follicle traits of half Merino half Romney F1 , and backcross three-quarters Merino quarter Romney gene mapping flocks}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {262-265}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Wool follicle traits and mean fibre diameter (MFD) of {\textonehalf} Merino {\textonehalf} Romney F{\textonesuperior} (MR), and {\textthreequarters} Merino {\textonequarter} Romney backcross (MRM) were compared. Skin and midside samples were collected from 25 ewes and rams of MR and 420 MRM progeny. MRM was lower than MR for MFD by 3.0 mm, follicle fibre area (FFA) by 162.4 mm{\texttwosuperior}, and diameter (FFD) by 4.1 mm, but greater for total follicle density (DEN) by 21.7 mm-2 , primary density (PD) by 0.8 mm-2 , and secondary to primary ratio (SPR) by 4.8 units. Most traits had significant differences (P<0.05) for birth year, breed and sire group, but only PD and SPR were significant for sex and birth/rearing rank. FFD was positively correlated (P<0.001) with MFD (r = 0.22), and the relationship had a common slope of 0.7, but intercepts were significantly different (P<0.01) across birth years (i.e. 13.5, 12.0, and 10.9 mm for born 1991, 1992, and 1993). }, issn = {1176-5283}, author = {Andrews RN and Beattie AE and Dodds KG and Wuliji T and Montgomery GW} } @conference {40908, title = {Accumulation of cadmium in kidney and liver tissue in the suckling Romney lamb from parturition to early weaning.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {137-138}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {In earlier work we investigated the accumulation of cadmium (Cd) in the developing foetus and compared the movement of Cd with that of zinc (Zn) into the liver and kidney. Concentrations of Cd in foetal tissue were ex-tremely low, although there was a small flux across the placenta at about 100d of development concomitant with that for Zn. There was no relationship of foetal Cd with the Cd status of the mother. It was only after parturition that Cd concentrations in liver and kidney started to increase (Rounce et al.,1995). We also showed that the rate of Cd accumulation in weaned animals was greatest at an early age when growth rates were also at or near their peak (Lee et al.,1996). The aim of this study was to define Cd accumulation in tissues of Romney neonates, as affected by relative Cd concentrations in pasture and milk from partu-rition to weaning.}, issn = {1176-5283}, author = {Rounce JR and Grace ND and Lee JL} } @conference {40883, title = {Across-breed genetic evaluation of New Zealand dairy goats.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {43-45}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The New Zealand dairy goat industry consists of 187 herds (33,500 does), from which 60 herds (12,600 does) supply milk for the Dairy Goat Co-operative. Most of the milk is used to manufacture whole milk powder for niche markets. Farm profitability can be increased through identifying and selecting superior animals for traits of financial importance such as milk yield. Across-breed estimated breeding values (EBVs) for milk yield adjusted for days in milk (MYA), unadjusted milk yield (MYU) and days in milk (DIM) of Saanen, Nubian, British, Toggenburg and crossbred dairy goats spread across 20 herds were estimated by Best Linear Unbiased Prediction (BLUP) procedures. A repeatability model was used to analyse the first eight lactation yields and included effects of herd-year-month, parity, additive genetic and permanent environment. Coefficients of breed composition and heterosis (assuming equal heterosis among any of the breeds) and days in milk were considered as covariables. Heritability and repeatability were 0.36 and 0.63 respectively. Evaluations were based on 6,517 lactation records of 3,856 does and 83 sires. Average milk production was 548 litres over an average lactation spanning 200 days. Pure-bred Saanen does had longer lactations (DIM) and out-produced other breeds in MYA and MYU. Two year old does produced an extra 150 litres of milk compared to one year old does. Peak production was at 5 years of age then production declined gradually. Young does had longer lactations than old does. Average EBVs for different breeds compared to a Saanen base were for MYU Nubian -291, British -242 and Toggenburg -106 litres, MYA -177, -193 and -51 litres and DIM -40, -17 and -19 days for each breed respectively. First cross heterosis was 105 litres (19\%) for MYU, 52 litres (9.5\%) for MYA and 18 days (9\%) for DIM. This first prototype evaluation allows the selection of does and bucks based on their estimated genetic merit and provides for routine genetic evaluation in the future. }, issn = {1176-5283}, author = {Singireddy SR and Lopez-Villalobos N and Garrick DJ} } @conference {40926, title = {Age at castration after puberty has no effect on carcass weight.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {196}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Bulls grow faster than steers but produce meat with lower quality, which presents fewer marketing opportuni-ties. Castration post-puberty improves several attributes of meat quality compared with bulls and theoretically it could be used to exploit the faster growth rates of bulls. How-ever, the 23 kg liveweight advantage of bulls over steers, when surgically castrated at 17 months-of-age, was lost in the subsequent 5 months to slaughter, because of poorer post-castration growth rate (Cosgrove et al.1996). It was not clear whether this was because of stress from surgical castration, or physiological effects associated with their age at castration. This trial examined the effect of age at castration on subsequent growth rate and carcass character-istics at slaughter.}, issn = {1176-5283}, author = {Cosgrove GP and Knight TW and Death AF and Lambert MG} } @conference {40896, title = {Agricultural ethics - a role in animal production?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {88-90}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Science and farming benefit society in innumerable ways, but like other human activities, are subject to value judgements of what is and is not acceptable. In addition to traditional measures of efficiency and profitability, the acceptability of agricultural practices is also determined by requirements of food safety, resource use, environmental and animal welfare criteria, and by social and philosophical views. Since moral issues may be difficult to deal with, and are determined by a wide array of influences ranging from philosophers to the media, it is important that we establish a means of clarifying them. Agricultural ethics provides such a common framework or language. This includes tradition and common sense (our common morality), and consideration of the rights of individuals and of the consequences of our actions. In addition, the role that virtues and myths play in determining the acceptability of agricultural practices can be incorporated. }, issn = {1176-5283}, author = {Fisher MW} } @conference {40907, title = {Is beef with yellow fat healthier for you than beef with white fat?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {134-136}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Fat samples were collected from 20 Angus grass fed steers 24 hours after slaughter. Fat colour was measured with a Chromameter (b* values) and the carotenoid concentration and fatty acid (FA) composition of the fat were analysed. Carotenoid concentration in the fat was low (1.54 {\textpm} 0.11 mg/g fat) compared to that found in vegetables. As b* values, and therefore the yellowness of the fat increased the proportion of saturated FA decreased (r = -0.58; P<0.001) and mono-unsaturated FA increased (r = 0.68; P<0.0001). The relationship was not as strong for carotenoid concentration even though the correlation between carotenoid concentration and b* values was high (r - 0.86; P<0.001). The conclusions were that the potential health advantages of beef with yellow fat compared to beef with white fat were small, especially as the relationships appeared to only apply within a herd. }, issn = {1176-5283}, author = {Knight TW and Death AF} } @conference {40900, title = {Behavioural of dairy heifers during adaptation to milking}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {105-108}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Effects of prior handling on behaviour of heifers at milking was studied in 42 Friesian heifers (reared on nurse cows, Herd A) and 36 monozygotic twins (calfeteria-reared, Herd B). Herd A heifers were allocated to 3 treatments: No Handling (N) - no handling or parlour experience; Limited Handling (L) - moved through the parlour during two sessions; or Familiarised (F) - 14 sessions during which animals were tamed, moved through the parlour and handled around the udder. Herd B heifers were allocated to N or F only. Behaviour at various stages of milking was observed during the first 14 milkings. Despite significant variation between individuals, all Herd A heifers significantly decreased moves and kicks from Period 1 (milkings 1 - 7) to Period 2 (milkings 8 - 14), and improved milk letdown but treatments were not significantly different at the various stages of milkings. However in Herd B, pre-milking handling and experience of the milking environment consistently reduced the frequency of adverse responses by heifers at most stages of milking. }, issn = {1176-5283}, author = {Bremner KJ} } @conference {40931, title = {Brief Communication: Increased litter size elicits cell proliferation in the lactating murine mammary gland}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {207-208}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Milk quality of dairy cows decreases both as lactation progresses and as milk yield declines (Lucey, 1996). De-clining milk yield has been associated with a diminishing population of secretory epithelial cells (Knight and Wilde, 1993). One approach to enhancing the persistency of lactation is to stimulate a wave of proliferation of epithelial cells within the gland. A new generation of epithelial cells could increase milk yield and might also improve the overall quality of the milk.}, issn = {1176-5283}, author = {Auldist D and McFadden T and MacKenzie DDS and Nicholas K} } @conference {40930, title = {Brief Communication: Seasonal and lactational influences on milk composition in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {205-206}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {In New Zealand, seasonal calving has created marked variations in the volume and composition of milk supplied to processors across the season. As a consequence, there are also seasonal variations in the manufacturing properties of the milk (Kefford et al.1995). In particular, milk from later in the season can have manufacturing properties which are different from those of early and mid-season milk. Milk from this time typically has elevated concentrations of blood proteins, low casein:whey ratios and an altered min-eral balance (Lucey, 1996). The 2 major factors attributed to causing this phenomenon are the stage of lactation (SOL) of the cows, and seasonal influences which affect both pasture and cows. In a seasonally-calving dairy sys-tem, the precise contributions of these factors to the re-ported changes in milk composition are difficult to define because of the confounding influences of other factors. The aim of the investigation presented here was to separate the respective effects of season and SOL on milk composition.}, issn = {1176-5283}, author = {Auldist MJ and Walsh BJ and Thomson NA} } @conference {40892, title = {Bulk and fibre diameter affect leather and woolskin quality of lamb skins}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {77-80}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Poll Dorset x Romney lambs were chosen from a group of 300 on the basis of measured diameter and bulk. The selected lambs made up four groups of twenty, that had the four possible combinations of low (LD) or high diameter (HD) (29 or 32 um), and low (LB) or high bulk (HB) (22 or 26 cm{\textthreesuperior}/g). Pelts were recovered at slaughter, assessed for woolskin tanning, processed to dyed crust leather and scored for the grain surface defect known as pinhole (1 to 5, best to worst). Suitability for woolskins was greatest for the high bulk groups (LDHB, 20; HDHB, 18), and least for the HDLB group (5), with the LDLB group intermediate (13). More pelts were found to exhibit pinhole in the high bulk groups (HDHB, 16; LDHB, 16 vs HDLB, 8; LDLB,10) and mean pinhole scores were higher (p <0.001) for these groups (HDHB, 2.5; LDHB, 2.4, vs LDLB, 1.7; HDLB, 1.5). Woolskins are a more appropriate product for finer and bulkier wool types, whereas less bulky wools of high diameter lend themselves to leather production, because they are unsuitable for woolskins and less prone to pinhole. }, issn = {1176-5283}, author = {Scobie DR and Cooper SM and Passman A and Young SR} } @conference {40872, title = {Can protein utilisation from pasture be improved?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {4-8}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Although temperature pasture plants usually contain sufficient protein to potentially support most types of animal production, this protein is utilised for ruminant production with relatively low efficiency because of the losses that occur via microbial deamination in the rumen. These processes are well understood, yet procedures that should theoretically improve protein capture, such as the addition of soluble carbohydrate or protected protein to the diet, are frequently not effective. The paper considers reasons for this situation. It also examines several additional reasons why plant protein utilisation may be impaired, such as high rumen degradability, hepatic detoxification of absorbed ammonia and its associated costs in terms of amino acid catabolism, and the relationship between amino acid supply to the duodenum and tissue amino acid requirements. The paper evaluates whether an enhanced supply of individual amino acids, or mixtures of amino acids, to the tissues might increase the production of meat, milk and wool. It also considers whether we have enough information to be able to assess the likelihood of using specific enhanced amino acid supply or novel combinations to manipulate product quality. The efficacy of various mathematical models of protein digestion and metabolism are evaluated in relation to our current knowledge of the subject. }, issn = {1176-5283}, author = {Ulyatt MJ} } @conference {40965, title = {A candidate gene approach to animal quality traits.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {294-296}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A variety of animal quality traits, particularly those associated with meat and wool production and disease resistance, have been the subject of sophisticated genetic analyses. Investigation of the biochemistry and physiology underlying disease or production traits has implicated particular proteins and hence genes as "candidates" for having major phenotypic effects. This makes the candidate gene approach a useful complement to animal genome mapping of markers and QTLs. We have applied the candidate gene approach for the sheep quality traits of meat tenderness and footrot resistance. A three allele system detected by polymerase chain reaction - single strand conformational polymorphism (PCR-SSCP) has been observed for the ovine calpastatin gene. Calpastatin is the specific inhibitor of the ubiquitous calcium-dependent proteases u-calpain and m-calpain. There is very strong population genetic and protein assay data in cattle to inversely correlate post-mortem calpastatin levels with meat tenderness. Assay of post-mortem calpastatin levels in aging lamb confirms an important regulatory role for calpastatin in sheep meat aging. Data sets from preliminary experiments testing the association of the three allele ovine calpastatin system with meat tenderness values and other meat quality characteristics show significantly different fillet tenderness, early post-mortem calpastatin and u-calpain levels between ewes with different calpastatin genotypes. The early post-mortem calpastatin levels and the longissimus dorsi pH at 24 hr post-mortem of sheep representing two different genotypes was also significantly different. The major histocompatibility (MHC) proteins of vertebrates have a role in presenting peptide fragments from pathogenic organisms to the systemic immune system. It is hypothesised that a component of resistance in sheep to footrot is based on an effective systemic immune response and hence controlled by MHC presentation. Sixteen alleles have been identified at the ovine MHC class II DQA2 locus and 8 at the DQA1 locus. A significant (p=0.001) association between footrot status and DQA2 genotype was observed in a halfsib family challenged with the disease under standardised field conditions. }, issn = {1176-5283}, author = {Palmer BR and Hickford JGH and Bickerstaffe R} } @conference {40927, title = {Cattle diet preference and species selection as influenced by availability.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {197-198}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Diet composition is partly determined by selective grazing. In general, cattle show a preference for a mixed diet (Cosgrove et al., 1996), with partial preference for legumes over grasses (Parsons et al., 1994). This work was conducted to determine if cattle modify their dietary pref-erence as the availability of a preferred species decreases.}, issn = {1176-5283}, author = {Torres-Rodriguez A and Cosgrove GP and Hodgson J and Anderson CB} } @conference {40889, title = {Changes in fibre and follicle characteristics related to wool bulk during the lifetime of Perendale ewes.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {65-69}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Wool and skin samples were collected annually at hogget shearing in October and thereafter in July for a further four shearings, from a total of 32 Perendale ewes born in 1990 and 1991 within lines selected for or against wool bulk. Time to form a crimp, follicle curvature and the proportion of para-meso cortical cells, increased towards an asymptote with increasing age. Proportion of fibres with a bilateral arrangement of cortical cells was maximal at 2 years of age and clean fleece weight, staple length and fibre diameter were maximal at 3 years of age. Fibre curvature decreased linearly, crimp frequency and follicle length decreased curvilinearly but wool bulk did not change with increasing age. The repeatability of individual characteristics decreased with increasing age. There was no significant difference in the relationship between core bulk and a combination of fibre curvature, fibre diameter and fibre diameter variation within each age group. }, issn = {1176-5283}, author = {Sumner RMW and Dick JL} } @conference {40949, title = {Changes in the activities of plasma membrane bound sperm enzymes during semen processing.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {251}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The physico-chemical changes in spermatozoa that take place during semen processing and storage regulate the fertilising ability of spermatozoa. Spermatozoa1 motil-ity, traditionally used as a marker of fertilising ability, does not indicate the true fertilising ability of spermatozoa (Smithet al., 1993),although motility is required for in vivo fertilisation. In this study we have monitored changes in activities of spermatozoa1 enzymes at various stages of semen processing. In future, these changes could be corre-lated to fertilising ability. It is also anticipated, that the information on these enzymes would improve our under-standing of basic sperm physiology.}, issn = {1176-5283}, author = {Oliver JE and Upreti GC and Duganzich DM and Smith JF} } @conference {40959, title = {Characterisation of muscle development in double muscled and normal bovine fetuses.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {278-281}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Double-muscled (DM) cattle have increased numbers of muscle fibres and most muscles are heavier, although certain muscles are reduced in weight relative to non-double-muscled animals. This study was undertaken to investigate whether this differential muscle growth seen in the adult was apparent during foetal growth. Foetuses with presumptive DM phenotype were compared to presumptive non-double-muscled controls (NDM), at four gestational ages. Body weight (p0.05). Heifers offered a high feeding level after 200 kg produced 9.6 kg more milkfat (P<0.01) and 6.6 kg more protein (P<0.01) than heifers offered the low feeding regime. These data suggest that Friesian heifers produce an additional 0.12 kg MS over their first lactation for each additional 1 kg liveweight gained during rearing. }, issn = {1176-5283}, author = {Penno JW and MacDonald KA and Bryant AM} } @conference {40912, title = {Effect of mil production and liveweight of feeding balanced or unbalanced supplements to cows grazing restricted summer pasture}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {151-153}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {To test whether supplementing summer pasture with a balanced ration would improve milk production and liveweight compared to supplementing with silage, four groups of 12 cows were offered with grazed pasture (P), P plus silage (S), P plus a ration which balanced the diet for crude protein (CP) and carbohydrate (PB), or P plus a ration which balanced the diet for neutral detergent fibre (NDF), non structural carbohydrate (NSC) and CP, (CB). The S, PB and CB treatments produced similar milk and milk protein yields, which were higher (P<0.01) than P. Milk fat yield for PB and CB was higher (P<0.001) compared to P but not compared to S. The average liveweight gain for S and PB was 16 kg higher (P<0.01) than P. No improvement in milk production was observed to feeding supplements which balanced either total carbohydrate and CP or NDF, NSC and CP compared to silage supplements. }, issn = {1176-5283}, author = {Neil PG and Thomson NA} } @conference {40918, title = {Effect of nitrogen fertiliser and concentrate feed on dairy production.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {172-175}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Over three dairy seasons (1993/94-1994/95) the input of additional N fertiliser (149 kg N/ha) and dairy meal (570 kg meal/cow) was evaluated in dairy farm systems with calving commencing on 20 June. Four farm systems were evaluated: Control LS (no extra N fertiliser, stocking rate, 3.6 cows/ha), NLS (21 kg N/ha after every grazing September to January, 3.6 cows/ha), NHS (N fertiliser same as NLS, 4.2 cows/ha) and NMHS (N fertiliser same as NLS, dairy meal fed at 0.5-3.0 kg/cow/day depending on pasture availability, 4.2 cows/ha). Each farmlet received a base application of 100 kg N/ha; 40 kg N/ha in March and 60 kg N/ha in July. The additional 146 kg N/ha increased (P<0.01) milksolids production by 107 kg/ha, or an additional 0.73 kg MS/kg of N fertiliser applied. The increased milksolids resulted mainly from increased pasture conserved (average of 192 kg DM/cow) which when fed out in summer/early autumn resulted in an increased lactation length of 17 days. A comparison of the NHS and the NMHS treatments showed that the feeding of dairy meal (ME, 13.7 MJ/kg DM and 11.1\% crude protein) increased (P<0.01) milksolids production by 77 kg/cow. An increase of 136 g MS/kg of meal fed. The advantage to meal feeding occurred throughout lactation but more in late lactation where lactation length was extended by 35 days. The greater proportion of the response to additional feed inputs from an increase in lactation length rather than an increase in production/cow/day. }, issn = {1176-5283}, author = {Thomson NA and Johnson RJ and Clough J and McCallum DA} } @conference {40922, title = {The effect of protein supply on the periparturient parasite status of the mature ewe.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {186-189}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Thirty two twin - and thirty two single - bearing ewes (W = 50.6 {\textpm} 0.13 and 48.9 {\textpm} 0.11kg respectively) were individually penned indoors nine weeks before lambing. Four dietary groups, balanced for pregnancy status were established utilising a 2x2 design for energy (E) and protein (P) levels. These were E1P1; E1P2; E2P1; and E2P2 (groups 1 - 4 respectively) and were based on a lucerne hay and barley diet. E1 and E2 were designed to promote 0 and +50g/d gain in maternal bodyweight, respectively. P1 and P2 contained approximately 120 and 200gCP/kg DM, respectively, the difference achieved through the inclusion of fishmeal in P2 diets. From seven weeks prior to and until parturition all ewes were trickle infected with 10,000 Teladorsagia circumcincta and 7,000 Trichostrongylus colubriformis larvae per day. Faecal egg counts were determined weekly from five weeks prior to and until three weeks after parturition when worm burdens were determined. Geometric mean faecal egg counts (epg) and worm burdens were 1610 and 145 epg and 12020 and 1540 worms, respectively, on low and high protein diets (P<0.01 in both cases) and 310 and 750 epg (NS) and 2290 and 8090 worms, respectively (P<0.01) in single compared to twin-bearing ewes. There was no effect of energy level. The periparturient breakdown in resistance to parasitic infection thus appears to be counteracted by protein supplementation. Supplementation of the ewe may provide an alternative parasite control strategy by reducing pasture contamination and may have greatest effect in prolific flocks. }, issn = {1176-5283}, author = {Donaldson J and Van Houtert MFJ and Sykes AR} } @conference {40950, title = {The effect of stage of cycle, oestrous synchronisation method and large follicles on superovulatory response in Merino ewes.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {252-255}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Superovulatory response to a single injection of PMSG (300ui) and of oFSH (3.6mg Ovagen{\textregistered}) given at either day 11, 16 or 18 after ovulation and a 7 day CIDR-G{\textregistered} or 30mg FGA sponge treatment was studied in Merino ewes. Follicle populations just before the administration of exogenous gonadotrophin and total ovarian response to treatment at day 5 of the next cycle were determined using transrectal ultrasound and laparoscopy respectively. The stage of the cycle had no significant effect on follicle population at the time of superovulation treatment or superovulatory response. Compared to FGA sponges, CIDR-G treatment reduced the number of 4-5mm follicles (2.83 {\textpm} 0.89 vs. 1.0 {\textpm} 0.3, P<0.05), the incidence of ewes with follicles >=4mm (100\% vs. 50\%, P<0.05) and tended to increase superovulatory response (6.3 {\textpm} 3.7 vs. 10.3 {\textpm} 3.5, P<0.1). Ewes were classified according to the absence (n=4) and the presence (n=17) of a large follicle (>/=4mm diameter) at the time of superovulation treatment. Ewes without a large follicle had higher superovulatory response (13.8 {\textpm} 2.7 vs. 5.0 {\textpm} 1.3, P<0.05) and tended to have lower numbers of anovulatory follicles (0.5 {\textpm} 0.7 vs. 1.8 {\textpm} 0.3, P<0.1). These results suggest that the presence of a large follicle at the time of exogenous gonadotrophin treatment reduces superovulatory response in ewes and that the incidence of such follicles may be reduced by the use of a 7 day CIDR-G treatment. }, issn = {1176-5283}, author = {King BJ and Hinch GN} } @conference {40879, title = {Effect of the Inverdale gene (Fec X) on fleece characteristics in Romney sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {29-32}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The effect of the Inverdale gene (FecX) on wool production traits was measured in a trial where Romney carrier rams (I) were crossed and backcrossed with high fleece weight-selected (HF) Romney ewes, and Romney non-carrier rams (+) with unselected (RC) Romney ewes. The trial generated 248 female progeny in five genotype subgroups: non-carrier (++){\textonehalf}RC and {\textonequarter}RC; heterozygous (I+){\textonehalf}HF and {\textonequarter}HF; and homozygous (II) {\textonequarter}HF. The live weight, fleece weight, wool characteristics and reproductive performance of these genotype subgroups were compared, and from corresponding genotype subgroups of male progeny (n = 307) were also evaluated for early growth and fleece traits. No differences were found for birth, hogget shearing and two-tooth live weights among genotypes. Greasy fleece weight was significantly (P<0.05) higher for I+{\textonehalf}HF ewes shorn as lambs (9\%), hoggets (8\%) and two-tooths (10\%) compared with ++{\textonehalf}RC. The important wool characteristics of yield, fibre diameter, bulk, staple length and staple crimp did not differ significantly between genotypes. The ovulation rate (combining subgroups with the same Inverdale genotype) was significantly (P<0.05) higher for I+ (2.3) than ++ (1.5) progeny (SED: 0.3). The results suggest that introgression of FecXI into fleece weight selection flocks will improve prolificacy in these flocks while ensuring high fleece weight. }, issn = {1176-5283}, author = {Wuliji T and Davis GH and Dodds KG and Andrews RN and Wheeler R and Turner PR} } @conference {40898, title = {The effect of the presence of steers on the behaviour of grazing yearling bulls.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {96-99}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Elements of the behaviour of sub-adult grazing bulls can lead to physical damage to animals, pastures and farm structures. We tested whether the presence of steers would modulate bull behaviour. In two experiments, 32 fourteen-month-old Friesian bulls (average live weight 346kg) and 32 Friesian steers (341kg liveweight) in groups of 10 to 32 animals were rotationally grazed on permanent pasture at a stocking rate of 23 cattle/ha for 12 to 16 days. The incidence of agonistic behaviour (mounting, teasing, butting, pushing, displaying) was monitored by continuous recording during two, 3 hour observation periods each day at 2 day intervals}, issn = {1176-5283}, author = {Nicol AM and Meikle AJ} } @conference {40929, title = {The effect of time-of-calving on dairy production.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {204}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The adoption of seasonal calving in New Zealand has lead to marked irregularities in the supply of milk to processors in terms of both quantity and quality. The need to accommodate peak milk flow means that manufacturing plants are under utilised for most of the year. Further, there are difficulties manufacturing high quality products early and late in the season. This study presents data from an all-year-round calving system which may help to overcome the above mentioned problems.}, issn = {1176-5283}, author = {Auldist MJ and Thomson NA and Walsh BJ} } @conference {40952, title = {Effect on time of year of treatment and selection for out-of-season breeding on the superovulatory response in ewes.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {258}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Previous results (Greaney, et al.,1991.) indicate that season of year has little effect on the response parameters of MOET although interactions between breed and season were recorded. Flocks within a breed have been selected for differences in seasonal lambing patterns based on ewe lambing date (Smith, et al.,1992). This trial reports the effects of this selection on the production and quality of embryos following superovulation at two times of the year as part of the cryogenic conservation process for these flocks.}, issn = {1176-5283}, author = {Smith JF and McGowan LT and Murray GR and Parr J and Pugh PA and Tervit HR} } @conference {40911, title = {The effects of methionine supply on milk composition and production of dairy cows in mid- lactation.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {147-150}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A trial assessing the production response of dairy cows to supplementation with methionine (Met) was conducted indoors over a 21-day period with 26 Friesian cows in mid-lactation and individually fed fresh perennial ryegrass/white clover pasture. Group 1 (n=9) received twice daily oral methionine (15 g/d) that was protected from rumen degradation (RPM; Lactet); Group 2 (n=9) was given a continuous intravenous infusion of free Met (15 g/d; MET-i.v.); and Group 3 (n=8) was given no methionine supplement (Control). Supplementary methionine tended to slightly depress feed intake but milk yield tended to be higher (P=0.08) for the MET-i.v. group compared with the Control and RPM groups (18.5 {\textpm} 0.48 vs 17.1 {\textpm} 0.45 and 17.2 {\textpm} 0.38 kg/d {\textpm} SE). Compared with the control group, there was a trend for Met (both MET-i.v. and RPM) to reduce milkfat concentration and to increase the concentration of casein. Neither lactose or whey nitrogen (N) concentrations were affected by the treatments. Methionine supplementation did not affect yields of total protein nor protein components; however, when protein and casein yields were adjusted to equal crude protein intake, Met supplemented cows produced significantly (P=0.05) more total protein and casein per unit of N ingested. These results suggest that post-ruminal Met supplementation improved the efficiency with which dietary protein was converted to casein in the pasture-fed dairy cow. More research is required to investigate which AA, individually or in combination, are likely to limit milk protein synthesis in the mammary gland of the pasture-fed dairy cow. }, issn = {1176-5283}, author = {Pacheco-Rios D and McNabb WC and Hill JP and Barry TN and MacKenzie DDS} } @conference {40905, title = {Effects of Mimosa Bark extract containing condensed tannins on rumen metabolism in sheep and milk production by grazing cows.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {126-129}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A Mimosa Bark extract (MB) was given to sheep and cattle to provide condensed tannins (CT) at levels which increased growth in lambs. The effects on rumen metabolism in sheep and milk production in grazing cows were studied in two experiments during spring 1994. MB contained 507g CT/kg bark and was administered as a water suspension (280g/litre). In Experiment 1, six rumen fistulated wethers were offered fresh pasture for two periods of 10 and 14 days, during which each sheep was drenched twice daily with 12.5 ml of either water or MB suspension (4.1 g CT/kg pasture DM intake), in a cross-over design. MB did not significantly affect DM intake, in sacco DM disappearance or apparent digestibility of DM or nitrogen (N), but ruminal ammonia-N and plasma urea concentrations were significantly decreased (P<0.05). In Experiment 2, 30 Friesian cows grazing mixed pasture were allocated to one of three treatments: undrenched control (C) or twice daily drenching with 90 (L) or 180 (H) ml of MB suspension (1.8 or 3.6 g CT/kg pasture DM intake) for three weeks. No significant differences in yields of milk or milk constituents were observed. Live weight and condition score changes did not differ significantly. Plasma urea concentrations were significantly lower (P<0.05) in treatment H than in treatment C. These results indicate that drenching with MB, at daily rates of 4 g CT/kg pasture DM intake, reduced ruminal protein degradation in sheep and cattle, but did not increase milk production. }, issn = {1176-5283}, author = {Mashudi and Brookes IM and Holmes CW and Wilson GF} } @conference {40913, title = {Effects of pasture intake and grain supplementation on milk nitrogen fractions}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {154-156}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Effects of underfeeding and supplementation on detailed milk components for 18 identical twin sets calving in July/August were assessed. Three treatments; 65\% ad libitum pasture (R), 65\% ad libitum pasture + 5.0 kg of cereal grain (S) and ad libitum pasture (F) were imposed in early (E), mid (M) and late (L) lactation. Milk was analysed for contents of fat, lactose and 12 nitrogen components. Treatment effects were generally greatest in E and M and often absent in L. Differences between F and R were significant by at least P>0.05, for 10, 7 and 2 of the 12 nitrogen components for E, M, L. Comparable differences for F-S were for E 6, M 5 and L 1. Changes were small in absolute terms and the extreme differences in type and level of feed suggest there is limited opportunity to manipulate nitrogen components in milk by feeding practices used in NZ. }, issn = {1176-5283}, author = {Petch SF and Bryant AM and Napper AR} } @conference {40933, title = {Effects of season-of-lambing, stage of lactation and ewe-age on the milk volume and composition of machine-milked Dorset ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {212-215}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Dorset ewes from the Flock House sheep milking flock were used to investigate the effects of season-of-lambing, stage-of-lactation and ewe-age on milk yield and composition. Lambs were removed 4 days after birth and ewes machine milked twice a day. Age of ewe effects were significant (P<0.05) for total and daily milk yield, duration of lactation and concentration of milk solids. Total milk yield increased from two (77 {\textpm} 4 L/ewe) to four years (108 {\textpm} 3 L/ewe) of age and declined in ewes five years and older (78 {\textpm} 4 L/ewe). The concentration of milk solids was highest for ewes five years and older. Ewes lambing in Spring and Winter had higher (P<0.05) total milk yields, durations of lactation and daily yields of milk solids, but lower daily concentrations of milk fat and total milk solids, than Summer and Autumn lambing ewes. Average concentrations of milk fat, milk protein and total milk solids increased as lactation progressed, while lactose concentration, daily milk yield and yield of milk solids decreased. Milk yield, milk solids concentration and milk solids yield can be modified by ewe-age, season-of-lambing and stage-of-lactation. }, issn = {1176-5283}, author = {Gosling LS and Knight TW and Newman S-AN} } @conference {40939, title = {Efficacy of an anoestrous treatment for dairy cows is reduced if administered within 3 weeks of calving.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {228-230}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The effect of treating dairy cows with anovulatory anoestrus (n=660) at various intervals post-partum was investigated. Treatment consisted of priming with progesterone using an intravaginal device (CIDR-B) for 6 days, with an injection of oestradiol benzoate 24h after device removal. The mean interval from treatment termination to conception tended to be greater for cows calved less than 3 weeks at diagnosis than contemporaries calved at least 3 weeks (32.8 6.3 vs 23.7 {\textpm} 1.1 days; p<0.1). Final empty rate was higher for cows diagnosed and treated within 3 weeks post-partum (39\% vs 13\%; p<0.001). Survival analysis accounted for the higher empty rate to determine the probability of pregnancy over time. Cows calved less than 3 weeks at treatment had a lower probability of pregnancy than contemporaries calved at least 3 weeks (p<0.01). This study found a negative effect of treating anoestrous cows within 3 weeks post-partum. Further work should define the nature of this problem and the value of delaying treatment until at least 3 weeks after calving. }, issn = {1176-5283}, author = {Nation DP and Macmillan KL and Taufa VK} } @conference {40895, title = {The ethically improved sheep concept.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {84-87}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The need to improve animal welfare and reduce chemical residues to maintain the competitive position of our sheep products is unquestionable. However sheep producers perceive that the required actions are in conflict with production, so there have been few recent changes which allay consumer concerns. This paper discusses possibilities for producing more attractive products without substantial reductions in production or increases in costs. It identifies gene pools that should be exploited to develop a polled sheep with a short tail, that is devoid of wool on the head, legs, belly and breech. It reviews evidence that shows such animals require less handling and chemical treatment, and produce more lambs. It is proposed that these traits be accumulated into "Ethically Improved Sheep". The concept of ethically improved sheep is not presented as a prescribed combination of breeds. There are a number of breed sources of each trait, and other traits should be introduced as they become available or important in the future. This would permanently reduce the need for husbandry practices that emulate the same effects, thus reducing input costs, pre-empting any bans and forestalling any trade barriers based on current husbandry practices. }, issn = {1176-5283}, author = {Scobie DR and Bray AR and O{\textquoteright}Connell D} } @conference {40897, title = {Evaluation of a vaccine to control bull behaviour}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {91-95}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {To determine the effect of Vaxstrate{\textregistered}, an anti-GnRH vaccine, on the development of bull behaviour, 90 Friesian bull calves were either castrated at 2 months of age (steers, S), immunised against GnRH at 2, 2.5, 4 and 7.5 months of age (immunocastrates, I2), at 4, 4.5 and 7.5 months of age (I4), at 7.5 and 8 months of age (I7.5), or left intact (bulls, B). Immunocastration delayed the prepubertal increase in testosterone. There were no differences in behaviour between immunocastration treatments. Mounting behaviour and paddock damage for immunocastrates and steers were lower than for bulls until 13 months of age, after which there was no difference between immunocastrates and bulls, and both were higher than steers. Bulls had a higher frequency of agonistic behaviour than both immunocastrates and steers; there was no difference between immunocastrates and steers until 16 months of age, when immunocastrates scored higher than steers. Immunisation against GnRH before puberty temporarily delayed the development of sexual and agonistic behaviour of young bulls and could provide a practical alternative to traditional methods used to control bull behaviour. }, issn = {1176-5283}, author = {Jago JG and Bass JJ and Matthews LR} } @conference {40948, title = {Evaluation of different staining techniques for determination of membrane status in spermatozoa.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {246-250}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Changes in the composition and integrity of spermatozoal membranes occur both during the normal capacitation and acrosomal reactions involved in the fertilization processes and as a result of different handling and storage procedures. Techniques to monitor these changes are essential to any study on methods of sperm preservation and such techniques should be both accurate, simple and rapid to apply. A series of tests were conducted to evaluate a range of staining techniques to measure the integrity of the sperm plasma membrane (permeable membrane indicates non-viable sperm) and to measure the status of the acrosomal membrane (indication of capacitation and acrosomal reaction). The possibility of a combination of stains to provide simultaneous answers to both parameters was also attempted. Semen both fresh and frozen from both rams and bulls was used. The stains evaluated were: Nigrosin-Eosin (NE), Nigrosin-Eosin- Giemsa (NEG), Hoechst 33258 vital stain as both wet and dry mounts, Carboxyfluorescein and Propidium Iodide (CF-PI), SYBR-14 and Propidium Iodide (SYBR-PI), Pisum sativum -fluorescein isothiocynate (PSA-FITC), Chlortetracycline (CTC) and a FITC- labelled monoclonal-antibody (Mab) to an acrosomal protein. The techniques were graded for their accuracy, ease of use, equipment requirements and also for repeatability or adaptability to spermatozoa in different media. No single or combination of techniques proved suitable for both plasma and acrosomal membranes and most techniques varied in their suitability for different semen preparations. }, issn = {1176-5283}, author = {Smith JF and Murray GR} } @conference {40936, title = {Expected pregnancy rate in recipient cattle, sheep and goats derived using a model incorporating embryo and maternal contributions to embryo survival}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {218-221}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Pregnancy rate to term after embryo transfer (ET) in cattle ranges from 30-50\%. A model is proposed which partitions embryo survival into independent and binomial embryo and maternal components. Parameters for these two components can be used to calculate expected pregnancy rates. In 35 out of 36 sets of data in which pregnancy data were recorded following contemporary single and twin ET, or single and twin ovulation, expected pregnancy rate was either within 5 percentage units or one standard deviation of observed pregnancy rate. Pregnancy rate changes in single ET recipients or single ovulating females are equally sensitive to changes in the embryo and maternal components. In contrast, pregnancy rate changes in twin ET recipients or twin ovulating females are more sensitive to changes in the maternal component. In conclusion, these data suggest that the model adequately describes embryo survival and pregnancy rates. Accordingly, research to improve the maternal component seems warranted in order to improve reproductive success. }, issn = {1176-5283}, author = {McMillan WH} } @conference {40901, title = {Farmer groups, a measure of their effectiveness}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {109-111}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {From 1993 to 1995 changes in sheep and beef cattle farmer learning styles; their beliefs about group interactions and their beliefs about the farm system were measured in three groups located in the upper North Island. The groups were each part of a group farm monitoring programme involving scientists from the Whatawhata Research Centre. Using a survey questionnaire, the study sought to identify ways of improving the delivery of technology to group members. Most group members expressed a preference for logical learning experiences (50\% of those surveyed) followed by problem solving (32\%), action (12.5\%), and social interaction (5.5\%). Belief maps which illustrate group interactions identified problems in group cohesion. Farm system belief maps identified distinct categories of farm system components, viz.: performance related technologies; relatively non-complex technologies; relatively complex technologies. Over time, beliefs about stock policies became more closely related to farm performance indicators such as profit. }, issn = {1176-5283}, author = {Webby RW and Paine MS} } @conference {40964, title = {Finding QTL{\textquoteright}s without markers: experience with FINDGENE.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {290-294}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {FlNDGENE is a mixed inheritance model computer program which can analyse extensive animal pedigrees. It partitions the observed variance into fixed effects. polygenic inheritance, a two allele major locus effect and a residual envimnmental variance. It do-es not require genotype information. Data from three New Zealand sheep experiments where faecal nematode egg count (FEC) information had been collected were examined by this method. They included a long term selection experiment for FEC in Rornneys at Wallaceville, another in Perendales at Ruakura, and a randomly mated Coopworth flock at Woodlands Research Station. All PEC traits were initially transformed using the function log.(x+lOO). The final model included the effect of sex/year contemporary group, birthday and polygenic inheritance in addition to a 2 allele Mendelian gene effect. Results from all three data sets suggested a dominant a{\textquoteright}utosomal gene for host susceptibility was affecting strongyle PEC values in the summer/autumn period with estimates of 0.37,0.69 and 0.72 log eggs/g for the single allele effect from Romney, Perendale and Coopworth flocks respectively. Corresponding values for dominance were 0.47,0.44 and 0.88 log eggs/g with susceptible allele frequency 0.14.0.55 and 0.69. When considered together, these results suggest that at least one QTL is affecting the development of host resistance to internal parasites in young sheep. The identification and characterisation of this QTL may result in useful novel methods of internal parasite control.}, issn = {1176-5283}, author = {McEwan JC and Morris CA and Bisset SA and Kerr RJ} } @conference {40923, title = {Free and conjugated levels of zearalenone in ewes mated on grass dominant pasture or chicory.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {190}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Zearalenone is an oestrogenic mycotoxin commonly found in New Zealand pastures (di Menna, and et al., 1987). Ingestion of zearalenone by sheep causes reductions in reproductive performance (Smith, and et al.,1990). It is likely that high zearalenone concentrations in pasture around mating will often be sufficient to affect reproductive per-formance of the ewe. Chicory pastures contain very low zearalenone concentrations and therefore have potential as a feed for ewes prior to and during mating. The aim of this trial was to determine the levels of free and conjugated zearalenone in the blood and urine of ewes grazed on either grass-dominant pasture or chicory prior to and during the mating period, and assess any subsequent effects on reproductive performance.}, issn = {1176-5283}, author = {Kramer R and Keogh RG and Sprosen JM and McDonald MF} } @conference {40963, title = {Genetic analysis of meat quality in cattle.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {288-289}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Geneticlinkagemapsenablescientists toidentify regionsofthegenome thatinfluenceproduction related traits. Sufficientnumber of polymorphic markers (5 1800) are available for a genome-wide quantitative trait loci (QTL) search and subsequent use of markers forselection.Selectionforcarcass traitshasbeen limitedb-xausecurrent marketsystemsdonotprovidecarcass information to thecattle producer. Information obtained from mapping studies will allow producers to select for carcass traits and other traits that are difficult and expensive to measure in production settings. Mapping information will also be used to identify the molecular mechanisms controlling the genetic component of carcass traits and other quantitative traits.}, issn = {1176-5283}, author = {Kappes SW and Stone RT and Smith TPL and Keele JW} } @conference {40876, title = {Genetic studies of bloat susceptibility in cattle.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {19-21}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Bloat costs the dairy industry about $50 million per year and one of the possible long- term solutions is to breed cattle for reduced susceptibility. Studies on two herds established at Ruakura in 1972/73, and selected divergently for high susceptibility (HS) or low susceptibility (LS) to bloat, have shown that: (1) bloat score on any single day of serious challenge has a heritability of 0.19{\textpm}0.04; (2) the within-animal repeatability of scores across days is 0.44{\textpm}0.02; (3) divergence of bloat score between herds has now reached 2.4 genetic standard deviations; (4) the recent response rate in the HS herd has been approximately linear whilst the LS response has plateaued; (5) 75\% of the HS herd and 2\% of the LS herd are at risk of death from bloat if left untreated. Alternative definitions of the bloat syndrome have been investigated; one of these (maximal bloat score) has a heritability of 0.30{\textpm}0.06. Using this definition, a mixed-inheritance segregation analysis was undertaken, which led us to the conclusion that a major gene for susceptibility was segregating as an autosomal recessive. The implication is that the use of non-carrier AI sires in industry could minimise the bloat problem in one generation, by avoiding production of all homozygous double-recessive progeny. }, issn = {1176-5283}, author = {Morris CW and Cullen NG} } @conference {40938, title = {Gestation length in Pere David{\textquoteright}s and red deer hybrids}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {225-227}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {P{\`e}re David{\textquoteleft}s deer (PD) have a 49 day longer gestation than red deer (283.4 {\textpm} 6.1 (SD) and 234.4 {\textpm} 3.4 days). In F1 hybrids (PD sire), male progeny had a longer gestation than females (268.8 {\textpm} 6.4, n=10 and 262.0 {\textpm} 4.5, n=10, P<0.01), both greater than the mid-parent mean of 259 days. The male and female progeny of F1 sires and red dams had a gestation length of 249 {\textpm} 5.5 (n=275). Segregation analysis suggests two normal distributions with a difference in means of 7 days. In the reverse hybrid (F1 dams), the gestation length of 242.5 {\textpm} 3.3 days (n=19) was significantly shorter than the backcross hybrid progeny of F1 stags. The control of gestation length in PD hybrids is clearly very complex although we have found evidence of two linked markers which individually account for 2.4 and 2.7 days of the difference in gestation length. }, issn = {1176-5283}, author = {Goosen GJ and Fennessy PF and Pearse AJ and McEwan KM} } @conference {40885, title = {Growing wool in tissue culture - which sheep breed is best?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {48-50}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Individual wool follicles were isolated from adult sheep and maintained in tissue culture for three days. Follicles from Merino, Poll Dorset and Suffolk animals were classified as fine wool types and were compared with follicles from Romney, English Leicester and Drysdale animals which were termed a coarser wool type. There were significant differences in both follicle survival and the rate of fibre growth between coarse and fine follicle types maintained in vitro. Only 48\% of follicles from animals with fine fibre types survived in tissue culture. In contrast, 84\% of follicles from coarse fibre types remained viable in vitro (P<0.01). The fibre growth rates of viable follicles was also significantly different between fibre types (P<0.01). Follicles isolated from animals classified as fine fibre types had a fibre growth rate of 108 {\textpm} 16um per day compared with 170 {\textpm} 12um per day fibre growth by animals with coarser fibre types. In vitro fibre growth by animals with large, straight follicles such as those from the English Leicester and Drysdale animals was greatest and a high proportion remained viable. Furthermore, follicles from these animals were easy to isolate relative to finer fibre types. Dissection of finer follicles was considerably more difficult, due to the decreased follicle size, curvature and high follicle density; factors which may be responsible for their reduced viability in vitro. }, issn = {1176-5283}, author = {Winder LM and Scobie DR and Bickerstaffe R} } @conference {40884, title = {Growth and onset of puberty in two genetically different lines of Holstein-Friesian cows, selected for either heavy or light body weight}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {46-47}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Heavier body weight affects dairy farm profitability through its effects on extra dietary energy requirements for maintenance and growth and on extra income from culled cattle; therefore it is now included in the new Animal Evaluation System used with New Zealand dairy cattle. The selection of two lines of Holstein-Friesian cattle began in 1989 using proven sires with either high (H) or low (L) estimated breeding value (EBV) for live weight (LW), but which were all of high genetic merit for milk solids yield. This paper reports on the onset of puberty and the pattern of growth from birth to first calving of heifers from these two genetic lines of cattle.}, issn = {1176-5283}, author = {Garcia-Muniz JG and Holmes CW and Wickham BW} } @conference {40920, title = {Growth of friesian calves offered three allowances of milk replacer.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {179-181}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Milk and milk products are a more expensive source of dietary nutrients than pasture and cereal based supplements. Therefore restricting milk intake could reduce the cost of rearing replacement cattle. Friesian calves (n=60) were allocated to three balanced treatment groups receiving a High (29.8 kg), Medium (21.8 kg) or Low (16.6 kg) allowance of milk replacer (MR). Calves offered the Low allowance were weaned from MR at day 42, while the other two groups were weaned from MR at day 49 of the trial. Calves were weighed at days 0, 49, 70 and 119 following a 12 hour fast. The liveweight gain of the High group was greater (P<0.05) during days 0-49 and 49-119 than the Medium and Low groups. The calves on the Medium and Low MR allowance were 3 kg lighter on day 49 and 7 kg lighter on day 119 than those of the High MR allowance. Differences in growth rates between treatment groups prior to day 49 were smaller than would be expected from the large difference in metabolisable energy intake from MR. Furthermore, reducing MR allowance did not increase meal intake as was expected. It is likely that the calves partially compensated for a lower MR intake by increasing pasture dry matter intake. When choosing to restrict the level of nutrition offered to the young calf, the effect on animal performance both before and after weaning must be recognised. }, issn = {1176-5283}, author = {MacDonald KA and Penno JW} } @conference {40882, title = {Heritability of resistance to flystrike in New Zealand Perendale sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {41-42}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The cost of fly strike to sheep farmers is considerable. Apart from animal deaths, other costs include: labour and chemicals for control, reduced wool value and poorer animal performance. Also, there is a cost in animal suffering and potential for chemical contamination of wool. Furthermore, fly resistance to currently available forms of chemical control is increasing. A complementary approach to controlling fly strike is to enhance the animal{\textquoteright}s genetic resistance via selection. }, issn = {1176-5283}, author = {Brandsma JH and Blair HT} } @conference {40916, title = {The impact of turnips on dairy production as evaluated by component trials, simulation modelling and farm systems research.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {165-168}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A comparison of different methods (component trials, systems modelling and whole farm trials) for evaluating dairy farm inputs is made using the example of turnips grown on-farm as a summer forage. Component studies conducted at the Taranaki Agricultural Research Station and at DRC showed respectively increased (P<0.01) milksolids production of 36 and 66 g milksolids (MS)/kg turnip DM. Modelling the use of turnips using a farm management model (UDDER) has shown the practice to be profitable in a dry year if the crop exceeds 8.0 tonne DM/ha and in a normal year, 10.0 tonne DM/ha. A programme designed to demonstrate the value of turnips on summer milksolids production (More Summer Milk) showed on 3 farms over 2 years a decrease of 16 kg MS/ha. The sowing of 7-9\% of the farm into turnips (DM yields varied from 6.5 - 11.5 tonne DM/ha) resulted in less pasture conserved (180 kg DM/ha) and, by the commencement of feeding turnips; reduced milksolids production (0.2 kg/ha/day), lower average pasture cover (360 kg DM/ha) and lower cow condition score (0.2 units/cow). Feeding turnips resulted in a small increase in milksolids production, insufficient to compensate for the initial production loss. UDDER simulated the farm situation prior to feeding turnips reasonably well but the response to turnip feeding was higher than occurred on-farm. The results highlight that the impact of a forage crop on dairy production cannot be predicted from short-term feeding trials or currently available farm systems models. }, issn = {1176-5283}, author = {Thomson NA} } @conference {40915, title = {Incorporating turnips into the pasture diet of lactating dairy cows.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {161-164}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Turnips have become a popular forage crop in New Zealand and Australia for supplementing dairy cows grazing pasture during the summer and autumn. However, it is unclear what combination of turnips and summer pasture best meets the dietary requirements of lactating dairy cows. New information was therefore gathered on the digestibility of turnips fed in conjunction with summer pasture and this was used in the ration balancing model, SPARTAN, to determine the optimum combination of turnips and summer pasture for a {\textquoteleft}large{\textquoteleft} dairy cow (500 kg, 17 l/d) during mid-to late-lactation. Twelve wethers (n = 3/group) were used to determine the in vivo digestibility of four diets with a summer pasture (P):turnip (T) dry matter (DM) ratio of: 100P:0T, 75P:25T, 50P:50T and 0P:100T. The DM digestibilities of the diets, fed at 1.0 kg DM/d, were 65, 71, 81 and 89\%, respectively. As the portion of turnips in the diet increased so too did the dry matter intake (0.64, 0.78, 0.77 and 0.93 kg DM/d, respectively). Relative to pasture, turnip was low in fibre and crude protein but high in available carbohydrate. The optimum portion of turnips, on a DM basis, when fed in conjunction with summer pasture was 21\% of the dietary intake. For the average New Zealand dairy cow, this equates to 3-5 kg turnip DM/d. A 100\% turnip diet would not meet cow requirements because of the low fibre and protein content of turnips, but a 100\% pasture diet could, providing it was reasonable of quality (ca. 65\% DMD and at least 17\% crude protein) and available in sufficient quantity not to restrict cow intake. }, issn = {1176-5283}, author = {McFerran R and Singh V and Parker WJ and Morris ST} } @conference {40875, title = {An Index to assist multiple trait selection of terminal beef sires in the UK}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {15-18}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A selection index with the objective of achieving economic improvements in saleable meat yield, calving ease and feed intake has been used in the UK beef industry since the mid 1980{\textquoteleft}s. In this paper, an improved index, which incorporates estimated breeding values for traits currently recorded in UK pedigree beef cattle, is described. The recorded traits are taken as birth weight, calving ease, gestation length, 400 day weight, ultrasonic fat and muscle depths, and muscling care. The breeding objective is made up of commercial carcass traits, calving ease and gestation length and is directed exclusively towards terminal sire buyers. When all available traits have been recorded in pedigree beef cattle herds, calving traits (birth weight, gestation length and calving ease) explain approximately 30\% of the variability in index scores, with the remainder explained by the growth and carcass traits. The expected economic superiority of progeny from the top 40\% of bulls ranked on the index, over the average bull, is {\textsterling}2.48 for carcass weight, {\textsterling}.79 for carcass conformation score, {\textsterling}-.05 for carcass fat score, {\textsterling}.37 for gestation length and {\textsterling}.24 for calving case. The overall economic superiority of progeny from the top 40\% of bulls ({\textsterling}3.82 is reduced by 17\% if both ease and gestation length are not recorded and by 10\% if ultrasonic scanning traits are not recorded. Two component indices (for calving and production trait groups respectively) are also proposed to allow commercial bull and semen buyers to adjust emphasis on the two groups of traits depending on their individual production circumstances. In conclusion, the new index incorporates new selection criteria, and a more rigorously defined and transparent breeding objective which should maximise future benefits from performance recording and Best Linear Unbiased Prediction (BLUP) genetic evaluations in UK beef cattle. }, issn = {1176-5283}, author = {Amer P and Simm G} } @conference {40940, title = {Induction of Parturition in Dairy Cows - A Survey from spring 1996 in the Waikato region.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {231-233}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Data were gathered relating to the practice of induction of premature parturition from farms in the central Waikato during spring 1996. A standard two-injection glucocorticoid treatment regime was employed. The reproductive tract of each cow receiving this treatment was examined 3 - 5 days post partum. Additional information relating to cow management was collected by interviewing participating herd-owners. Preliminary data relating to subsequent reproductive performance of a subset of the cows are also presented. Accurate data were obtained for a total of 691 cows on 31 dairy farms. The mean induction rate was 10\% (range 2 - 24\%) of the cows in each herd. The distribution of the ages of induced cows was skewed, with 25\% of cows being 3 yr old. Of the 35\% of cows which calved to a single injection of glucocorticoid, 76\% were within 30 days of full term based on expected calving dates. Inadequate progress in udder development following the first injection was seen in 11\% of cows, of which 78\% were more than 30 days premature. Only 56\% of cows completed the routine two-injection regime. Dystocia requiring at least moderate intervention occurred in 15 cows (2\%). There were no cows with retained foetal membranes (RFM) on 33\% of farms, but the overall incidence of RFM in cows receiving routine induction was 14\%. No intervention was required for 43\% of these, which resolved spontaneously within 48 h of calving. Milk fever was the complication most frequently reported (overall incidence 2.8\%) and contributed to 3 of the 6 reported deaths. Preliminary data from 11 farms indicated that 7\% of cows were not presented for re-breeding. Only 12\% required treatment for anoestrum. The mean calving to 1st service interval was 64 {\textpm} 2 days, and 53\% had appeared to hold to 1st service. }, issn = {1176-5283}, author = {Verkerk GA and Goble G and McDougall S and Woods M and Clark B and Macmillan KL} } @conference {40893, title = {Influence of reducing wool fibre diameter away from the winter minimum, on fibre length after carding}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {81-82}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The length of fibres after carding is strongly influenced by the minimum fibre diameter (MinFD) in winter in Low Staple Tenacity (LST) and High Staple Tenacity (HST) Romney sheep. In this study a further weakness was induced by a temporary reduction in fibre diameter at a point away from the winter minimum, and the influence on fibre length after carding (barbe) was determined. Forty adult rams of four genotypes (LST, HST, Drysdale and Merino) were offered a restricted diet for 14 days in early February. Fibre diameter was reduced over the treatment period in LST (by 26\%), HST (19\%), Drysdale (5.5\%) and Merino (0.5\%). Barbe was only significantly associated with MinFD during treatment in LST (r{\texttwosuperior}=0.62, P<0.01) and not at all with change in fibre diameter. For each 1 um reduction in MinFD during treatment, barbe was reduced by 1-3mm. }, issn = {1176-5283}, author = {Smith MC and Bray AR} } @conference {40894, title = {An investigation of techniques used to predict fleece rot incidence in sheep.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {83}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Fleece rot is a bacterial exudative dermatitis in sheep (Burrell, 1988) which occurs when the skin has been con-tinuously wet for 4 - 9 days. It is a major predisposing factor to the incidence of bodystrike - a form of flystrike -with a high genetic correlation of 0.9 (Atkins and McGuirk, 1979). This trial investigated the possibility of using fleece colour characteristics to predict the incidence of fleece rot in sheep.}, issn = {1176-5283}, author = {Keown A-M and Reid TC} } @conference {40921, title = {Lamb and hogget growth on different white clover and ryegrass cultivar mixtures in southern New Zealand.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {182-185}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Lamb and hogget liveweight gains from five different white clover/ryegrass mixtures were compared at AgResearch, Gore from 1992-1995. The mixtures involved comparisons between white clover cultivars (Huia and Demand), ryegrass endophyte types (endophyte-free and 187BB which produces no lolitrem B) and ryegrass species (Marsden and Greenstone hybrid ryegrasses and Pacific perennial ryegrass). Averaged over 3 years, Marsden/Demand produced significantly greater lamb growth rates and final carcass weights (15.0 cf. 14.1 kg) compared with Marsden/Huia pastures. The advantage in lamb production from Demand based pastures was directly linked to the higher yields of white clover.}, issn = {1176-5283}, author = {Young OA and Widdup KH} } @conference {40924, title = {Liveweight gain and parasite resistance of lambs treated with slow-release albendazole capsules.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {191}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {It has been reported that non-parasitised lambs treated with an oral oxfendazole drench had higher live weight gain and a reduced immune response to gastrointestinal para-sites than untreated controls (Stankiewicz et al., 1994). The aim of this trial was to determine whether treating lambs with controlled-release albendazole capsules had any ef-fect on the performance of non-parasitised lambs fed a low or high protein diet and on subsequent resistance to larval challenge.}, issn = {1176-5283}, author = {Niezen JH and Robertson HA} } @conference {40886, title = {Localisation of transforming growth factor Beta1-like immunoreactivity in foetal and mature skin from Romneys and Merinos.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {51-56}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Skin samples removed from sheep foetuses at weekly intervals during gestation were studied to examine how between breed differences in follicle development are induced. Immunocytochemical methods were used to examine the localisation of the peptide transforming growth factor-Beta1 (TGFb1 ). Our observations indicate general localisation of TGFb1 in the skin between 83 and 104 days of gestation in both Romney and Merino breeds. This coincides with the maturation of primary follicles and the development of sebaceous and sweat glands. TGFb1 immunoreactivity was maintained in primary follicles (particularly the presumptive inner root sheath cells in lower regions of the bulb), sweat gland and sebaceous gland but by day 134, a more discrete localisation was observed in the inner root sheath (IRS), outer root sheath (ORS) and sebaceous gland with intense immunoreactivity in the sweat gland. The timing of the localisation and the lack of difference between the breeds suggest that variation in the TGFb1 level is unlikely to have a regulatory role in primary and secondary follicle initiation but may play a role in regulating the diverse differentiation pattern of various cell types within the follicle. The intense immunoreactivity in mature sweat glands suggests a possible osmoregulatory role for TGFb1 in the skin. }, issn = {1176-5283}, author = {Hocking-Edwards JE and Thomas DG and Birtles MJ and Harris PM and McCutcheon SN and Wickham GA} } @conference {40942, title = {Manipulating Ovaries{\textquoteright} Follicle Wave Patterns Can Partially Synchronise Returns to Service and Increases the Pregnancy rate to Second Insemination}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {237}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The recognised roles of oestradiol in the bovine oestrous cycle include stimulating behavioural symptoms of oestrus, facilitating spontaneous luteolysis and initiating the ovulatory surge of LH. An important ancillary role with progesterone is to inhibit the release of gonadotrophins (Burke et al.,1996). Oestradiol administered by injection or per vaginum can perturb follicle development with consequent effects on responses to superovulation (Bo et al.,1994) and on synchrony patterns (Macmillan et al.,1993). The hypotheses which were tested in the following trial were that injecting a low dose of oestradiol benzoate (1mg ODB) at about mid-dioestrus during the cycle follow-ing first insemination: (i) would not reduce the pregnancy rate to this insemination; but (ii) would alter the pattern of returns to service; and (iii) could affect the pregnancy rate to the second insemination.}, issn = {1176-5283}, author = {Macmillan KL and Taufa VK and Day AM} } @conference {40962, title = {Mapping Productive Traits in Livestock - Introduction}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {287}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {In the last 7 years a large scale world-wide effort has produced genetic linkage maps of most important livestock species. As a result of this we now have the tools to follow the inheritance of every piece of every chromosome in any pedigree, breed or selection line CIOSS. In addition the methods that enable us to analyse the genes and DNA contained within the chromosomes have undergone many incremental improvements so that it is now a realistic research goal to find and characterise the genes responsible for multigenic or quantitative traits in livestock species.}, issn = {1176-5283}, author = {Crawford A} } @conference {40947, title = {The measurement of ovine follicle stimulating hormone (FSH) bioactivity utilizing a recombinant human FSH receptor bioassay.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {243-245}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Recently a bioassay for human FSH has been described based on FSH stimulation of cyclic AMP production by a Chinese hamster ovary (CHO/FSH-R) cell line stably expressing the human FSH receptor (FSH-R cells). In this study, the viability of this bioassay for measuring ovine FSH was examined. Freshly thawed FSH-R cells were bulked up in culture, and aliquots of 250,000 cells/well dispensed into 48 well culture dishes and incubated overnight at 37{\textdegree}C. The assay culture media was then replaced with 0.25 ml fresh media (α-MEM + 0.1\% BSA + 0.25 mM 3-isobutyl-1-methyl-xanthine) containing varying doses of FSH preparations, and the cells incubated for 4 h at 37{\textdegree}C. The assay culture media was then removed and stored frozen at -20{\textdegree}C until assayed for cyclic AMP by radio immunoassay.}, issn = {1176-5283}, author = {Young W and Henderson K and Hudson N and Moore L and Albanese C} } @conference {40899, title = {Measures of stress and growth suppression in surgically castrated bulls}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {100-104}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The effects of surgical castration of pre- and post-pubertal bulls on measures of stress and growth were investigated in two separate experiments. In Experiment 1, 17-month-old Friesian bulls (n = 6 per treatment) were either left untreated (Controls), handled and administered local anaesthetic (Handled), or handled, administered local anaesthetic and surgically castrated (Castrates). In Experiment 2, 5-month-old Friesian bulls (n = 10 per treatment) were either left untreated (Controls) or surgically castrated without local anaesthetic (Castrates). Castrates in Experiment 1 had higher (P<0.05) plasma cortisol concentrations 7 and 14 days after treatment compared with Handled bulls and lower (P<0.01) gains in body weight for 14 days compared with Controls. There were no effects of treatment on plasma non-esterified fatty acid, b-hydroxybutyrate and urea concentrations. Castrates in Experiment 2 had higher (P<0.05) plasma concentrations of cortisol and the inflammatory protein haptoglobin for 7 days after treatment compared with Controls. The feed intake and weight gain of Castrates were also lower (P<0.05) than that of Controls during the week following treatment. It is concluded that the castration of cattle causes stress, resulting in a check in growth which is possibly mediated via a reduction in feed intake. }, issn = {1176-5283}, author = {Carragher JF and Knight TW and Death AF and Ingram JR and Matthews LR} } @conference {40932, title = {Metabolic changes in the mammary gland of sheep prior to, and at, parturition.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {209-211}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Four sheep fitted with an indwelling catheter in the femoral artery and a transit time ultrasonic flow probe around the left pudendal artery (supplying the mammary gland) were used to quantitate changes in mammary blood flow (MBF) in late pregnancy and lactation, and to determine the extraction of glucose and oxygen by the mammary gland. Mammary vein blood samples were collected by venipuncture. Considerable variation existed in the pattern of change in MBF between individual sheep. In two animals, MBF through the pudic artery fitted with the flow probe doubled to 600 mL/min on the day of lambing (DL), while in the other two sheep, MBF varied little in response to lambing. Possible explanations for this difference between individuals are discussed. Glucose extraction trebled on DL from 6.0 to 18.7\% (P<0.01) and remained high during lactation in relation to milk output. Oxygen extraction by the mammary gland peaked during the last week of pregnancy (at 45.7\%) and during lactation it was related linearly to milk output. }, issn = {1176-5283}, author = {Revell DK and Harris PM and Cottam YH and Reynolds GW and Lee J} } @conference {40906, title = {Methane emission from grazing sheep and cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {130-133}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Measurements of methane emissions from individual sheep and dairy cows grazing typical New Zealand perennial ryegrass/white clover dominant pastures are reported. These are the first measurements reported from grazing sheep, and among the first from grazing cattle. The measurement technique, using a marker gas (sulphur hexafluoride), enables emission rates to be determined from analyses of "breath" samples collected while grazing. More than 250 measurements of daily methane emission from 50 sheep (8 months old) were made, with flock-mean emission 18.9{\textpm}0.8 g/d. Emissions were weakly correlated with feed intake, and they represented a 4.6{\textpm}0.1\% average loss of gross dietary energy. The corresponding mean emission based on 40 measurements of daily emissions from 10 lactating dairy cows was 263{\textpm}10 g/d, approximately 6.2\% of estimated gross energy intake. A notable feature was the large inter-sheep variability in daily methane emission (range 140\%) that could not be attributed to variable intake. This would appear to suggest an appreciable diversity of methanogenic response to digestion, and may be significant in the search for strategies to control emissions of this greenhouse gas. }, issn = {1176-5283}, author = {Ulyatt MJ and Lassey KR and Martin RJ and Walker CF and Shelton ID} } @conference {40914, title = {Milksolids response in early lactation to condition score and concentrate feeding}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {157-160}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Effects of condition score (CS) at calving and concentrate supplementation over early lactation on milksolids production (MS), liveweight, CS change and intake were investigated in spring 1995. Differential feeding before calving resulted in high CS (HCS) and low CS (LCS) herds of 5.6 and 4.7 (P<0.001) respectively. After calving (10 August) the HCS and LCS herds were split (n=10) and either fed (+) or not fed (-) 3 kg DM/cow/day of rolled barley for 48 days. During the treatment period each herd was offered a similar pasture allowance of 22 kg/cow/day. A 27 day carryover period followed with no supplementation. Treatments were grazed separately throughout. During supplementation the liveweight gain (P<0.01) and change in CS (P<0.05) was greater for LCS than HCS. Cows on + concentrate gained more liveweight (P<0.01) than - concentrate. CS at calving had no effect on milk yield or composition. Concentrate increased (P<0.001) milk, fat and protein yields and protein \%. Feeding 144 kg DM/cow of concentrate increased (P<0.001) milksolids by 16.5 kg/cow. No significant interaction occurred between CS at calving and concentrate but for HCS cows the response to feeding concentrates was 21.2 kg MS/cow compared to the response for LCS cows of 11.8 kg MS/cow. During the feeding period, pasture intake was greater (P<0.05) for LCS (12.5 kg/cow/day) than HCS (11.0 kg DM/cow/day). Concentrate had no effect on pasture intake. No treatment effect on pasture intake occurred in the carryover period. These results suggest, that at the pasture allowance post calving of 22 kg DM/cow/day, a CS at calving of 4.7 is adequate to sustain similar milksolids production in early lactation as cows calving with CS of 5.6. }, issn = {1176-5283}, author = {Mudford CJ and Thomson NA and Holmes CW} } @conference {40956, title = {Muscle distribution in lamb progeny from several breeds.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {267-270}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Leg and shoulder composition (fat, muscle and bone) and some linear fat and muscle distribution measurements were taken on 458 lambs produced by 39 strains and breeds of ram born in 1992, 1993 and 1994. Lambs were either Romney or Romney-cross. Texel-cross lambs had the highest proportion of muscle in the leg and shoulder cuts with the Poll Dorset-cross lambs having a similar amount. Southdowns, American Suffolks and Romney strains had least muscle, and apart from the American Suffolk, also had most fat. The fat selected Southdown-cross had the highest \% carcass fat. There was no significant difference between any of the sire groups in the proportion of the major defatted leg primal cuts. All genotypes had a similar leg muscle cut distribution, breed differences being only in the relative proportions of muscle to fat and bone. The Texel-cross had the highest weight (at the same carcass weight) of psoas muscle and the ultrasonically selected Poll Dorset progeny had the highest proportion of measured lean as longissimus muscle. }, issn = {1176-5283}, author = {Kirton AH and Duganzich DM and Mercer GJK and Clarke JN and Dobbie JL and Wilson JA} } @conference {40941, title = {Non-invasive pregnancy determination in mares by enzymeimmunoassay of estrone sulphate concentrations in faeces.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {234-236}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Measurement of faecal estrone sulphate by enzymeimmunoassay was evaluated as a non-invasive means of monitoring pregnancy status in mares. Faecal samples from non-pregnant mares had a mean {\textpm} s.e.m. estrone sulphate concentration of 23 {\textpm} 0.9 ng/g (N=242). In pregnant mares, mean faecal estrone sulphate concentrations increased progressively during the first half of gestation. The values rose from a mean {\textpm} s.e.m. of 49 {\textpm} 4 ng/g (N=121) for samples collected <80 days post-mating, to 122 {\textpm} 9 ng/g (N=30) for samples collected 161 to 180 days post-mating. Thereafter, faecal estrone sulphate concentrations remained relatively constant for the remainder of pregnancy. From 150 days post-mating onwards, <2\% of faecal samples from pregnant mares had an estrone sulphate concentration below 66 ng/g which was the value 3 standard deviations above the mean value found for non-pregnant mares. Following foaling or foetal death, faecal estrone sulphate concentrations returned quickly to non-pregnant levels. Using this estrone sulphate enzymeimmunoassay, mares may be confirmed pregnant once faecal estrone sulphate concentrations rise above the 66 ng/g cut-off value. Those mares in which faecal estrone sulphate concentrations have not risen above 66 ng/g by 150 days post-mating may be considered to be non-pregnant. Measurement of faecal estrone sulphate thus offers a convenient, non-invasive means of monitoring pregnancy status. }, issn = {1176-5283}, author = {Henderson KM and Perkins NR and Wards RL and Stewart JI} } @conference {40960, title = {Nutritional effects on Beta-carotene concentrations in the fat of beef cattle.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {282-285}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Yellow fat reduces the acceptability and value of beef table cuts within the high priced Asian markets. The concentration of carotenoids in fat, leads to this yellowness. A systems experiment which ran for 2 years, studied the effects of nutrition and age on fat carotenoid concentration (FCC). In each year, rising 1-year (R1) and 2-year (R2) Angus steers were offered either full access to winter and spring feed (fast rotation, FR); or were nutritionally restricted during winter (slow rotation, SR) and then given full access to feed during spring. Fat biopsy samples were collected every 4 months and carotenoid concentration determined. FCC increased as animals became older. The effect of the nutritional growth path was to increase FCC during winter where feeding was restricted, particularly in the R1 steers. In both years, the SR systems compensated during spring, with both live weight and FCC being similar for the 2 nutrition treatments by the end of spring. From a practical perspective, farmers who seek to supply beef with satisfactory fat colour should not restrict feeding during the period of 3-4 months prior to slaughter. The experiment also provided data which allowed FCC to be followed from weaning through to slaughter for individual animals. These data provided the opportunity to investigate the prediction of carcass FCC based on earlier fat measurements. Correlations (r) ranged from 0.31 at 24 months to 0.71 at 3 months before slaughter. Correlations are not sufficiently strong to justify early selection of cattle for targeted markets and growth paths. However, there is opportunity for processors to use fat biopsy and objective colour measurement techniques in the selection and purchase of cattle for high priced markets. }, issn = {1176-5283}, author = {Boom CJ and Sheath GW} } @conference {40943, title = {Oestradiol Concentrates the Synchrony Pattern in Heifers Treated with Progesterone and Prostaglania F2alpha.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {238}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Oestradiol has been successfully used to synchronise oestrus and ovulation in anoestrous dairy cows first treated with progesterone for at least 5 days and then injected with oestradiol benzoate (ODB) during the following 24 to 48 h (Macmillan et al., 1994). The ovulatory effects are associ-ated with the ability of oestradiol to induce a surge of LH, especially during pro-oestrus. Although oestradiol has been injected in the period of pro-oestrus following an injection of prostaglandin F2α(PGF), this form of oestra-diol use has not been advocated even though the precision of synchrony is enhanced (Macmillan, K.L.; Burke, C.R.,1996).}, issn = {1176-5283}, author = {Macmillan KL and Taufa VK} } @conference {40917, title = {Optimum white clover content for milk production.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {169-171}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Nine Jersey and nine Friesian cows in late lactation and housed indoors were fed diets containing either 20, 50 or 80\% white clover with the balance perennial ryegrass. During the first 10 days cows were fed ad libitumand during the second 10 days feeding was restricted to 75\% of metabolisable energy requirement. Milk yields of cows fed 50\% and 80\% clover diets ad libitumwere not significantly different but were 18\% greater (P<0.05) than for cows fed 20\% clover. During restricted feeding, when intakes were not significantly different, milk yields of cows fed 50 and 80\% clover were again not significantly different but were 10\% higher (P<0.10) than for cows on 20\% clover. Clover content had no effect on milk composition. The experiment indicated increased yields weredue mainly to increased intakes associated with high clover diets, and also the higher nutritive value of the clover. Results showed the optimum clover content for milk production was 55-65\%.}, issn = {1176-5283}, author = {Harris S and Clark D and Jansen E} } @conference {40966, title = {Parasite resistance: A genome scan approach to finding markers and genes.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {297-300}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A systematic approach for finding regions of the genome that are important in the control of productive traits has only recently become available. The advent of microsatellite markers for sheep and other domestic ani- mals (Crawford et al. 1991) and their subsequent place- ment on linkage maps (Crawford eta/. 1995, Kappa et al 1997) has provided a set of highly informative markers densely spread across the genome. With these reagents we now have the ability to follow the inheritance of each region of every chromosome in any cross. Providing we have pedigrees in which genes which have an important influence on the trait of interest are segregating, we can systematically identify the regions of the genome in- volved. This process has become known as the genomic scan. }, issn = {1176-5283}, author = {Crawford AM and Green R and Cuthbertson RP and Wright C and Vlassoff A and Squire DR and West CJ} } @conference {40910, title = {Plasma potassium - an indicator of protein catabolism in deer?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {144-146}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Elevated plasma potassium (K+ ) concentrations well outside the normal range for deer have been reported during the rut. The effects of season and nutrition on plasma K+ concentration were examined in two experiments in farmed red and fallow deer. In Experiment 1 castrate and entire red stags were fed ad libitum on pasture and blood sampled fortnightly over 11 months. Except for a transitory peak at the beginning of Experiment 1, red entires and castrates showed no abnormal plasma K+ concentrations over the 11 month period. In Experiment 2, a castrate group of fallow bucks were fed to lose a similar amount of live weight as entires over the rut. When plasma K+ concentration was expressed as a function of changes in muscle weight there was a significant negative relationship (P<0.05) in the castrates. There was no relationship in the entires, although the measure of change in muscle weight could have been confounded by changes in water content of the musculature over the rut. The occurrence of hyperkalaemia in deer was variable. Further work is required to clarify the conditions that lead to its expression. }, issn = {1176-5283}, author = {Jopson NB and Fennessy PF and Thompson JM} } @conference {40968, title = {Positional cloning to identify genes.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {302-304}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Target genes, identified by their phenotypic effect, can be located by positional cloning. Current genetic maps in livestock species lack the necessary detail for direct application in these projects. Fine maps of each target region must be developed using a variety of strategies. These include chromosome specific libraries and comparative mapping. A physical map of the region is generated by identifying overlapping clones containing large DNA inserts. All genes from the region are sought and candidate genes identified. The resources being developed in livestock projects, including the search for the Booroola (FecB) locus, and complete expression maps for the human genome will greatly facilitate future positional cloning projects in livestock. }, issn = {1176-5283}, author = {Montgomery GW and Lord EA and Lumsden JM} } @conference {40874, title = {Progeny performance of industry and index selected Angus bulls.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {12-14}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The Department of Lands and Survey (LS) introduced an objective-based, open nucleus Angus breeding program in 1976 to produce bulls for its commercial properties. Previously, commercial sires were purchased from numerous industry sources (IND). To demonstrate the usefulness of objective selection and to determine performance differences between the two sire sources, 600 mature Angus cows and heifer replacements were randomly mated to either LS or IND bulls beginning in 1976. Replacement female offspring from these matings were then randomly mated to either LS or IND bulls to produce second generation offspring (GEN2). Herd size was maintained and matings continued through 1986. Growth performance of all GEN2 animals was recorded through weaning. After weaning, only female performance was recorded. Least-squares methodology was used to determine differences between the two genetic sources (IND or LS). Traits measured were weaning weight (WW); cow ratio, calf weaning weight per 100 kg of cow weight (CR); yearling weight (YW); and 18 month weight (18M). The statistical model for all traits included year of birth (YOB), sire source of calf (CSS) and dam (DSS), sex (where applicable), age of dam (AOD), age at weighing, and the interactions of YOB and CSS, YOB and DSS, AOD and CSS, AOD and DSS, and CSS and DSS. Calf{\textquoteleft}s sire source was significant (P<.01) for WW and CR, and approached significance for YW (P<.1) but was not significant for 18M (P>.1). Dam{\textquoteleft}s sire source was not significant for any trait (P>.1) nor was the interaction of CSS and DSS (P>.1). The WW of progeny with LS maternal grandsires and LS sires was 4.6{\textpm}1.8 kg greater than progeny with IND sires and IND maternal grandsires. Differences in weights taken subsequently were smaller. Although not statistically important, in a production scenario where all male progeny were sold at weaning, benefits of the introduction of an objective-based, breeding scheme were evident. }, issn = {1176-5283}, author = {Enns RM and Nicoll GB} } @conference {40873, title = {Progress with selection to change age at puberty and reproductive rate in Angus cattle.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {9-11}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Trying to improve beef cow pregnancy rate by genetic selection within a breed is generally considered to be slow and difficult. We have investigated a promising option which involves selecting to change age at puberty in heifers and then exploiting the genetic correlation with lifetime pregnancy rate. Angus herds were established from a common foundation population in the early 1980s, and were then selected from 1984 for reduced age at puberty (AGE-) or increased age at puberty (AGE+), with a control herd for comparison. Relative to the AGE+ herd, heifers born in the AGE- herd in 1993 and 1994 were 83 days (=20\%) younger at puberty (P<0.001), and their half brothers had 2.0 cm (=6.6\%) greater scrotal circumference (P<0.001). Corresponding live weights in the AGE- herd were 17\% less at puberty (P<0.001), not significantly different between herds at birth, weaning or 8 months of age, and 3.5\% higher as yearlings (P<0.01) than in the AGE+ herd. Conception rates for the 1992-95 matings were 91.2 and 71.2\% (P<0.001) for AGE- and AGE+ yearling heifers, but not yet significant at 89.6 and 85.0\% respectively for older cows. Restricted maximum likelihood estimates of heritability for age at puberty and scrotal circumference (mean of 3 measurements) were 0.27{\textpm}0.04 and 0.48{\textpm}0.05, with a genetic correlation of -0.29{\textpm}0.10. Phenotypic standard deviations for age at puberty in the AGE- and AGE+ herds were 51 days for each herd. However, within-herd heritabilities for age at puberty were 0.32{\textpm}0.11 and 0.13{\textpm}0.14 for the AGE- and AGE+ herds, respectively, which suggests to us that different modes of inheritance should be investigated in each herd. }, issn = {1176-5283}, author = {Morris CA and Wilson JA} } @conference {40903, title = {Protein-tannin complexes are susceptible to proteolytic degradation.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {116-119}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {In vitro studies were carried out to determine the factors that affect formation and dissociation of the protein-tannin complex (PTC) under conditions simulating those found in the digestive tract of the ruminant. For this study purified condensed tannins (CT) from the following tropical plants were used: Acacia harpophylla, Acacia aneura, Acacia saligna, Acacia holosericea, Tipuana tipu, Albizia chinensis, Flemingia macrophylla, Grevilea robusta, Casuarina cristata, Casuarina cunninghamiana, Azadarachta, Leucaena leucocephala, Leucaena pallida and Leucaena diversifolia. English spinach was selected as the source of soluble protein and during the growing phase, the plants were exposed to a 14C-CO2 atmosphere for 48 h. Following exposure, the foliar protein ribulose 1,5 biphosphate carboxylase/oxygenase, (rubisco) was isolated. The radioactive labelled protein was incubated with the isolated samples of CT for 2h at 39{\textdegree}C. The mixtures were then centrifuged and the percentages of bound protein (precipitate) and unbound protein (fluid phase) were determined. Formation of the protein-tannin complex (PTC) occurred over a range of pH 3-7. Above this pH 7, no PTC was formed. To determine the effects of pH on the dissociation of the PTC, the precipitate was incubated with buffers over a range of pH 3-9. It was found that acidic or alkaline pH was responsible for only 8 and 14\% of the dissociation of the PTC, respectively. However, addition of abomasal and intestinal fluid from both sheep or cattle increased dissociation of PTC to more than 60\%. Further analysis showed that pepsin and trypsin are largely responsible for the dissociation which occurs with the abomasal and intestinal fluids respectively. }, issn = {1176-5283}, author = {Diaz-Hernandez A and Nixon MJ and Ball FM and Leng RA and Rowe JB} } @conference {40890, title = {The relationship between compounds causing scourable diffuse yellow and the yellowness of clean and greasy wool.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {70-72}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {As part of a study of the chemistry of wool yellowing, a pilot survey was conducted to examine the frequency of occurrence of two yellow compounds previously isolated from the suint of a few yellow fleeces. The relationship between the amounts of these compounds present and the degree of discolouration was examined in clean and greasy wool from Merino (n = 48), Halfbred (n = 12), Corriedale (n = 26), Romney/Crossbred (n = 52), Cheviot (n = 10) and Perendale sheep (n = 8). The numbers of samples analysed, the mean yellowness (tristimulus Y-Z) and the relative proportions of the two yellow compounds detected are given in Table 1. Because not all the data was obtained for all samples, the number of data points used in each analysis may vary from those in this table. Of the 172 wool samples examined, one yellow compound was present in all of them, and a second yellow compound in 91\%. There was little relationship between the amounts of these compounds and the yellowness of the greasy wool. Furthermore, there were no significant relationships between the amounts of either compound and the yellowness of the clean wool. The results suggest that the coloured compounds isolated are universally distributed in the wool of New Zealand sheep and may be responsible, in part, for the degree of yellow discolouration in greasy wool. They would appear to have little, if any, impact on the colour of clean wool. }, issn = {1176-5283}, author = {Wood JE and Reid TC} } @conference {40935, title = {Removal of cisternal milk following milk accumulation for 9 hours does not increase total yield during once-daily milking}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {217}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Once-daily milking (ODM) of dairy cows in New Zealand results in a yield loss of 15-25\% (Carruthers V.R. et al.,(1993)). This loss is not associated with the total storage capacity of the udder, although some studies have shown that increase in the volume of milk in the cistern is associated with reduced yield loss during ODM (Knight C.H. and Dewhurst R.J. (1994)). The following experi-ment was undertaken to determine whether removal of cisternal, but not alveolar milk, at the p.m. milking, de-creased the production loss during ODM.}, issn = {1176-5283}, author = {Farr VC and Davis SR and Stelwagen K} } @conference {40945, title = {The responses of lactating cows treated for anoestrus to an oestradiol capsule or an oestradiol injection.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {241}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Postpartum anovulatory anoestrus is a mjor form of infertility among cows in dairy herds inNew Zealand. The currently recommended treatment involves a 5-day prim-ing with progersterone (P4) released from a CIDR TM device (InterAg, NZ), with a 10 mg gelatin of oestradiol benzoate (ODB) and 1 g lactose capsule (CIDR TM; InterAg, NZ) placed in the grooved surface of the device preceding device insertion, and an injection of ODB (CIDIROLTM ; InterAg, NZ) given intramuscularly at 24 to 48h following device removal.}, issn = {1176-5283}, author = {Taufa VK and Macmillan KL and Nation DP and Day AM and Ashcroft MJ} } @conference {40904, title = {Responses to protected amino acids or protected protein in dairy cows grazing ryegrass pastures in early lactation.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {120-125}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Two-hundred-and-four Friesian dairy cows (4-9 years old) were allocated to 1 of 9 groups at calving (n=22-23) in August-September 1995. All cows grazed ryegrass pastures at a stocking rate of 3.1 cows/ha and received some maize silage and barley for the first weeks after calving. In addition, they received one of three experimental supplements in early lactation (weeks 2-11) or mid lactation (weeks 12-22) or late lactation (weeks 23-33). Experimental supplements were 1 kg/d barley only (BAR), 1 kg/d barley with 17 g/d protected methionine/lysine (BML) or 1 kg/d protected protein meal (PPM). Individual pasture intake was estimated twice (5 days) during each lactation stage with sub-groups of cows (n=8) using the alkane technique. Preliminary results for cows in the early and late lactation groups are presented. In cows supplemented in early lactation, supplement intake was lower than anticipated (BAR, BML and PPM: 0.73, 0.67 and 0.41 kg/d respectively). Mean pasture intake (17.4 kg dry matter [DM]/d), milk solid production (2.07 kg/d) or changes in live weight (+23 kg) and body condition (+0.02) did not differ between groups. Gross milk composition and milk protein composition were also unaffected. In cows supplemented during late lactation, supplement intake was 0.83, 0.84 and 0.68 kg/d for groups BAR, BML and PPM respectively. Mean pasture intake (14.3 kg DM/d), milk solid production (1.49 kg/d) and change in live weight (+11 kg) during the period of supplementation did not differ between groups. Although further work with higher levels of supplementation with protein or amino acids is required, these results suggest that neither MP supply nor methionine/lysine supply were limiting milk production in dairy cows grazing ryegrass-based pastures during early or late lactation. }, issn = {1176-5283}, author = {Rusdi and Van Houtert MFJ} } @conference {40961, title = {The role of calsequestrin in muscle function.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {286}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Meat quality depends on muscle quality which is related to the regulation of muscle function by the contrac-tion-inducing ion, calcium. If the process of Ca 2+ uptake, sequestration or release at the level of the muscle cell is interrupted or altered, there is a loss of muscle quality. Two well-characterized conditions that result directly from al-tered Ca2+ regulation are porcine malignant hyperthermia and chicken crook neck syndrome.}, issn = {1176-5283}, author = {Trumble W and Wesson C and Jones KR and Uljee AE and Wrigglesworth AL} } @conference {40888, title = {Seasonal changes in fibre and follicle characteristics related to wool bulk in Perendale ewes.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {61-64}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Wool bulk is one of six key characteristics that describe processing performance and the final potential of wool products and is largely influenced by fibre crimp and fibre diameter. Measurements of seasonal variation in wool growth, and fibre and follicle characteristics associated with wool bulk were made over 19 months in Perendale ewes within lines selected for or against wool bulk to assess their potential impact on processing performance. Wool growth rate, mean fibre diameter, mean follicle depth and follicle activity displayed a minimum value in July and a maximum in December-January. Mean fibre curvature and follicle curvature grade had an opposing seasonal trend with a maximum in winter and a minimum in summer. The opposing seasonal cycles for fibre curvature and fibre diameter, compensated each other across seasons with no change in the expression of wool bulk throughout the year. }, issn = {1176-5283}, author = {Dick JL and Sumner RMW} } @conference {40953, title = {Seasonal Patterns in Production and Quality of Semen of Rams from Flocks Selected for or against an Early Breeding Season.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {259}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Seasonal patterns of semen production and sperm quality from rams of different breeds have been previously reported (Colas, 1979). Flocks within a breed have been selected for differences in seasonal lambing patterns based on ewe lambing date (Smith, et al.,1992). This trial reports the effects of this selection on the production and quality of semen from rams in those flocks.}, issn = {1176-5283}, author = {Smith JF and Parr J and Smith JK and Briggs RM and Duganzich DM} } @conference {40880, title = {Sheep breeding objectives and selection criteria of Wairarapa and Tararua sheep farmers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {33-36}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The adoption of recommended breeding practices, such as the use of performance recorded rams and objective selection of flock replacements, by sheep farmers is believed to be poor. This issue was investigated through a stratified random interview survey of 74 Wairarapa and Tararua wool growers. Equal emphasis was placed on breeding for wool and meat production by 73\% of the farmers surveyed. Only 23\% quantified their breeding objectives numerically in terms of wool production, lambing performance or carcass weights. Criteria, scored on a 4 point "importance" scale (1 = No; 4 = Great), for ewe hogget selection were: structural soundness (3.8 {\textpm} 0.1; mean score {\textpm} se) absence of black fibres (3.7 {\textpm} 0.1); visual body size (3.5 {\textpm} 0.1), wool characteristics (3.0 {\textpm} 0.1) and face cover (3.0 {\textpm} 0.1). Fleece and live weight recording was used by 22 and 54\% of the farmers, respectively, for ewe hogget selection. Ram selection criteria were similar as those for ewe hoggets, with measured fleece weight (3.4 {\textpm} 0.1) and selection index (3.1 {\textpm} 0.1), both being rated lower on average than structural soundness, conformation and body size. Farm management consultants and WoNZ Production Officers were rarely consulted for advice on ram selection (mean score 1.2 and 1.1 on 5-point scale) in comparison to ram breeders (2.9) and other farmers (1.8). The decision on whom to purchase rams from was most commonly made on the basis of the breeder{\textquoteleft}s reputation (29\%) and similarity of farm type (19\%). Price (1\%) and breeder advertisements (1\%) were not identified as important determinants of whom to buy rams from. Overall, the survey confirmed a general lack of objectivity in sheep breeding and selection decisions. More effective ways of promoting the value and use of objective sheep breeding information to sheep farmers are required. }, issn = {1176-5283}, author = {Gavigan RG and Parker WJ} } @conference {40958, title = {Short-Term Grain Feeding and its Effect on Carcass and Meat Quality.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {275-277}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Forty-five crossbred steers weighing 540-580 kg were assigned to three treatment groups. Group 1 received pasture only for 58 days; Group 2 grazed at a similar herbage mass to Group 1 and were supplemented with 4 kg/hd/day of a concentrate ration; Group 3 were on a feedlot and fed 8 kg/hd/day of concentrate together with 2.0 kg/hd/day of straw. Groups 2 and 3 each had a 28 day pre-conditioning period followed by a 30 day concentrate feeding period. Final fasted liveweight, liveweight gains, and carcass weights for concentrate, concentrate plus pasture and pasture alone groups were 546 {\textpm} 9, 548 {\textpm} 9, 547 {\textpm} 8 kg; 0.33 {\textpm} 0.09, 0.42 {\textpm} 0.09, -0.05 {\textpm} 0.09 kg/hd/day and 293 {\textpm} 7, 315 {\textpm} 4 and 313 {\textpm} 4 kg, respectively. The concentrate plus pasture and pasture only fed groups had greater fat depths. Ultimate pH was slightly lower in concentrate fed than pasture fed cattle but there were no differences in fat colour or tenderness as measured in the laboratory. Plasma carotene levels were significantly lowered by a factor of 10 in the concentrate fed group compared to the grass fed group, but this did not affect fat colour when measured subjectively at the meat processing plant or objectively in the laboratory. Apparently feeding concentrates for 30 days is insufficient to affect fat colour characteristics. }, issn = {1176-5283}, author = {Morris ST and Purchas RW and Burnham DL} } @conference {40925, title = {Sire by finishing environment interactions for carcass and meat quality traits in beef cattle.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {192-195}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Genotype by environment interactions can result in bulls having different genetic merits applicable to different environments. Beef cattle have traditionally been finished on pasture in New Zealand. The desire to meet perceived market requirements for meat quality has encouraged progeny testing and led to feedlotting. The objectives of this study were to evaluate sires on the basis of performance of their pasture-finished steer progeny, their feedlot-finished steer progeny and to compare the assessments of these sires from offspring in each environment. Fourteen Angus sires had progeny in both environments comprising 54 pasture-finished steers and 148 feedlot-finished steers. Estimated Breeding Values (EBVs) of each sire were obtained separately for eight traits that were measured for both pasture and feedlot progeny. Product-moment correlations between sire EBVs based on pasture-finished progeny and EBVs based on feedlot-finished progeny averaged 0.11 (range -0.16 meat colour to 0.50 subcutaneous fat depth). The expected distributions of these correlations between EBVs were obtained by simulation for a range of null hypotheses determined by the true genetic correlation between performance in the two environments using Monte Carlo simulation. The expected distributions of correlations between environments were determined for differing numbers of progeny per sire and for the effect of preselecting prior to entering the progeny test. The distributions of correlations were used to determine whether the low observed correlations between EBVs estimated from each environment were likely to have arisen from chance sampling or were truly indicative of genotype by environment interaction. Based on actual progeny numbers per sire in each environment there were significant (P=0.05) sire by finishing environment interactions for most traits analysed. Increasing the number of progeny per sire would increase the chance of detecting such interactions, in that case separate progeny testing programmes for each environment may be necessary. }, issn = {1176-5283}, author = {Charteris PL and Garrick DJ and Morris ST} } @conference {40957, title = {Sources of variation in the ultimate pH of M. longissimus from prime steers.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {271-274}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The ultimate pH (pHult) of beef is an important quality determinant, that can be affected by pre-slaughter muscle glycogen concentrations. The two trials reported here evaluated relationships between pre-slaughter conditions and behaviour of mobs ofsteers processed at Manawatu Beef Packers Limited and the subsequent incidence of high-pH beef. Trial 1 involved 405 2- and 3-year steers in 12 mobs, with a mean ({\textpm}sd) carcass weight of 341.2 ({\textpm}28.2)kg. Cattle were held for either c. 3h prior to slaughter (1/2of each mob) or c. 27h. Mean carcass weight was lower for the 27h-mobs (P < 0.01), but the extra 24h holding time had no effect on mean pHult , bruising score, carcass fat depth, or meat colour. The percentage of carcasses with a pHult> 6.0 varied from 0 to 27\%, but was not closely related to any of the pre-slaughter conditions monitored (eg. feeding levels, conditions during yarding, loading and transport,weather conditions, and conditions at the plant).}, issn = {1176-5283}, author = {Purchas RW and Keohane BE} } @conference {40902, title = {Technology design and marketing: Case studies for beef cattle breeding}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {112-115}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {An assessment of farmer beliefs and attitudes to predict likely use of new beef breeding cow technologies was undertaken with farmers from Northland, King Country, and Hawke{\textquoteleft}s Bay. In workshops, farmers evaluated the use of twinning through embryo transfer, artificial insemination with sex-sorted encapsulated semen, and terminal sires. The proportions of farmers likely to use the technologies to some extent, were 55, 72, and 83\% respectively. Farmers identified the important interactions that would be expected to occur if the technologies were introduced into typical beef farming systems in their area. Attitudes towards each technology and towards selected technology attributes, indicated important considerations for future development of the technologies. These included their ability to: improve breeding cow returns; achieve easy care calvings; and integrate with sheep enterprise management to provide leafy feed for lambs. Consideration of these attributes in technology research, development, and marketing, is likely to improve technology uptake. }, issn = {1176-5283}, author = {Parminter TG and Wilkinson RS and Tarbotton IS and Carter JC and Perkins AML and McMillan WH and Smeaton DC} } @conference {40871, title = {Time to change{\textquoteright}}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {1-3}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The topics discussed in the fifty-six Presidential ad-dresses preceding this one can be broadly categorised into those that are personal statements on personal research areas and those that are {\textquoteleft}tub-thumping{\textquoteright} about the Society or agricultural research in general. In recent times, Presidents Sykes ( 1986), Jury (1990) and Nicol (1992) have all thumped their tubs and exhorted the Society to change both in attitude and modus operandi. Alas, their exhortations have had little impact. They pointed the direction but we did not follow. So it is my intention to try again, for the simple reason that if we do not change, we will not survive as a Society, or maybe even as animal scientists. }, issn = {1176-5283}, author = {Davis SR} } @conference {40967, title = {Translation of information between human and livestock gene maps using a deer interspecies hybrid mapping panel.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {301-302}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The burgeoning knowledge associated with the gene maps of humans and mice can provide key information for the identification of genes underlying production traits in livestock. In tbeo~~, it should be possible to tramlate information associated with a human chromosomal location to a chromosome location in sheep, cat\& or deer. However, in practice, livestock gene maps often require more comparative links to make accurate \&anslation possible. We have taken a novel approach to livestock comparative mapping by using an interspecies hybrid mapping panel to map both gene loci and sheep and cattle microsatellites. The panel comprises DNA from 346 l/4 Pere David{\textquoteright}s deer (Ekxphurus dnvidinnuj 3/4 red deer (Cervus elaphur) backcross progeny of male FI P\&e David{\textquoteright}s deer x red deer hybrids. We are using this deer mapping resource to relate the sheep, cattle and human gene maps and by mapping key markers from each.}, issn = {1176-5283}, author = {Tate ML and Mathias HC and McEwan KM and Anderson RN} } @conference {40881, title = {The use of fly attractants to encourage flystrike for sheep selection purposes.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {37-40}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The incidence of flystrike in New Zealand flocks is about 3\% in most years. This low level of prevalence makes it difficult to discriminate between potential flock replacements based on naturally occurring flystrike. Selection decisions could be improved if either the rate of flystrike could be raised artificially or an easily measured trait that has a higher level of occurrence could be found. The second approach is used in Australia where fleece-rot has both a higher incidence rate than flystrike and is highly genetically correlated to susceptibility to flystrike. However, the incidence of fleece-rot in New Zealand dual-purpose sheep is not sufficiently high to allow its use as an indirect indicator. In a effort to find a means of artificially increasing the incidence of flystrike, groups of hoggets were brought indoors and exposed to the Australian green fly Lucilia cuprina. In total, 5 trials (10 animals/treatment) were run to compare: the susceptibility of Romney vs Perendale sheep, using wetting, dung or homogenised liver as attractants. Wetting was applied along the back from a watering can while the other attractants were applied to a patch on the shoulder, mid-back and rump. About 2000 gravid flies were released into a fly-proof room along with the penned sheep. The main results of these trials were: a) It was very difficult to get an established maggot population on clean wet sheep; few eggs were laid and no cases of established strike occurred; b) Dung acted as a moderately successful attractant; maggots were hatched on the sheep but none developed to the skin penetrating stage; c) Liver acted as a very successful attractant and maggots developed on all treated sheep. No between-breed differences occurred with wetting, dung or liver attractants. Further studies are required to refine the use of attractants. In particular, an attractant that is less powerful than homogenised liver but more potent than wetting or dung is required before moving onto large-scale field trials. }, issn = {1176-5283}, author = {Blackwell GL and Potter MA and Cottam YH and Blair HT} } @conference {40946, title = {Use of pregnant dairy cows in product development of the intravaginal progesterone releasing (CIDR) device.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {242}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {This study aimed to confirm that pregnant cows could be used to study release rates of progesterone (P4), the hormone of {\textquoteleft}pregnancy{\textquoteright}, from the CIDR device without compromising pregnancy. The seasonal nature of the New Zealand dairy operation presents only a brief window for large scale CIDR studies, if the treatment system is limited to non-pregnant cows.}, issn = {1176-5283}, author = {Burke CR and Burggraaf S and Bunt C and Rathbone M and Macmillan KL} } @conference {40951, title = {Use of teaser ram effect to advance lambing date in a farm systems study}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {256-257}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The normal onset of seasonal oestrous behaviour in Romney derived breeds can be advanced by the use of teaser rams and social facilitation. This technique was used, as part of a farm systems trial, to advance the start of lambing from September 1 to August 1. In the first year, the use of Dorset rams at ratios of 0, 3, 6 and 9 per 100 ewes resulted in 0, 72, 81 and 86\% respectively of ewes ovulating at the silent oestrous. In the following year, a ratio of 8\% was used in combination with CIDRs after the silent oestrous. This extra manipulation gave no advantage in terms of ewes lambing and ewes lambing multiples. Use of Coopworth rams instead of Dorsets and priming the teaser rams by exposure to oestrogen treated spayed ewes likewise had little impact. Over all years, teasing resulted in a similar proportion of ewes lambing (87\%) compared to the later lambing non-teased groups (89\%). However, the early groups had only 37\% multiple births compared to the late lambing ewes (48\%, P<0.01). The 31 day advance in start mate date in the early ewes resulted, on average, in a 27 day advance in mean lambing date (P<0.01). When weaned on the same date the early lambs were 2.27 kg heavier than the late lambs (P<0.01). }, issn = {1176-5283}, author = {Smeaton DC and Webby RW and Sheath GW} } @conference {40887, title = {Volume measurement of wool samples.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {57-60}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A rapid procedure for measuring the volume of wool samples was developed, using a gas pycnometer. Volume was measured on midside wool samples, harvested monthly, from thirteen sheep breeds representing a range of wool medullation categories. Clean sample weights between two and ten grams and the fourth sequential volume measurement are recommended. Volume was also calculated, using the sample mass and the theoretical density of wool. Measured and calculated volumes were the same for non-medullated wools (p=0.20), but not for highly medullated wools, the measured volume was 25\% greater than the calculated volume (p<0.001). }, issn = {1176-5283}, author = {Merrick NC and Scobie DR} } @conference {40862, title = {The accumulation and clearance of equol in the blood of ewes grazed on either high or low formononetin red clovers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {373-377}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Formononetin is the major red clover phytoestrogen responsible for reproductive dysfunction in sheep. Formononetin is metabolised in the rumen to equol which is significantly more oestrogenic. This study was conducted to characterise the accumulation of conjugated and free equol in the blood of ewes grazed on either high formononetin (cv Pawera, 0.57\% of dry matter) or low formononetin (cv G27, 0.25\% of dry matter) red clovers over a 1, 2 or 3 week period and the subsequent clearance of equol after removal from the red clover. Seventy mixed age ewes were divided into 7 treatment groups (n=10). Each group grazed either Pawera or G27 red clover for 3, 2 or 1 week or ryegrass (control group) prior to mating as one flock on ryegrass pasture. All ewes were regularly blood sampled. Once mated, the ewes were laparoscoped and returns to service recorded. Conjugated equol concentrations in both Pawera and G27 ewes increased over the first 2 days to 23.97 }, issn = {1176-5283}, author = {Kramer R and Keogh RG and McDonald MF} } @conference {40762, title = {Across breed evaluation of dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {12-15}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = { Genetic analysis of dairy cattle has been undertaken using an animal model including pedigree records since 1940 and performance records since 1986. The animal model analyses all breeds and breed crosses simultaneously allowing accurate estimation of hybrid vigour effects for milk production, liveweight, four survival traits and 16 linear type traits. The animal model allows the effects of induction, age at calving and herd- year-season to be taken into account when estimating an animal}, issn = {1176-5283}, author = {Harris BL and Clark JM and Jackson RG} } @conference {40806, title = {Animal behaviour and stress: impacts on meat quality}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {162-166}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Animal behaviour can deleteriously affect meat quality through three different pathways: exertion/activity, physiological stress responses and perceptions of welfare. In this review of published work we will describe each pathway, and discuss methods for minimising their impacts on both the physicochemical and animal welfare aspects of meat quality. We conclude that whereas the physicochemical quality of meat can be improved by some post-slaughter carcass handling treatments, public perceptions of meat quality can only be enhanced by improved animal handling practices to reduce stress.}, issn = {1176-5283}, author = {Carragher JF and Matthews LR} } @conference {40765, title = {Assessing the value of breeding technologies to dairy farmers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {22-24}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The adoption of technologies for breeding dairy cattle requires estimating the financial return to dairy farmers in conjunction with assessing the financial implications to the breeding company. This paper describes a procedure currently used by the Livestock Improvement Corporation. The net on-farm income generated as a result of the new technology is calculated. This is discounted to a Net Present Value allowing for the cost of the technology. A positive NPV indicates the adoption of the technology is of benefit to the dairy farmer. The breeding company also should assess the funding implications of any change. Typically this is expressed in terms of the increase/decrease in price of products and services.}, issn = {1176-5283}, author = {Rendel J and Jackson R and Harris B and Allison T and Shannon P and Burton L and Tempero H} } @conference {40767, title = {Assessment of female traits for genetic improvement of fertility in dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {27-31}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = { The objective of the present study was to investigate the suitability of various fertility traits for describing the reproductive performance of dairy cows in New Zealand. Using a data set from herds participating in the Livestock Improvement Sire Proving Scheme over the 1986/87 to 1992/93 seasons, the following female fertility traits have been investigated. Based on the start of mating (STOM) in a particular herd, the intervals from STOM to first mating (SMFM) and to the successful mating (SMCO) were calculated and compared to the internationally used traits that are based on the calving date, such as, calving to first mating (CFM) and calving to successful mating (days open, DO). Further traits considered are age at calving (AC), number of matings per conception (NS), first to successful mating (FMCO), calving interval (CI) and two traits that indicate whether a cow became pregnant within 21 or 42 days of STOM (PR21, PR42). The traits defined for the unique conditions in New Zealand, SMFM, SMCO, PR21 and PR42 emphasize the economic importance of reproduction to dairy production. The comparison to overseas studies using DO, FMCO and CI showed that New Zealand dairy cows had a better fertility performance than overseas cows.}, issn = {1176-5283}, author = {Grosshans T and Xu ZZ and Burton LJ} } @conference {40766, title = {Associations between milk protein genetic variants and production traits in New Zealand dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {24-27}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Records on 7574 first lactation cows were used to investigate the associations between milk protein genetic variants and 305-day milk, fat, and protein yields. Friesians, Jerseys and Ayrshires and their crosses were represented in the data. Milk samples were typed for 3 casein (CN) proteins as1-CN (B,C), b-CN (A1, A2), k-CN (A,B) and 1 whey protein b- lactoglobulin (LG) (A,B). The model used to describe the data included the additive genetic effect of animal and the four protein phenotypes. The interaction between breed and as1-CN phenotype and between breed and b-CN phenotype was significant (P<0.05) for milk, fat and protein yields while the interaction between breed and k-CN phenotype was significant (P<0.05) only for protein yield. The interactions associated with the as1-CN and k-CN phenotypes were scale effects while the interactions associated with b-CN resulted from reranking of protein phenotype across the breeds. Friesian and Jersey as1-CN BB cows had higher (2.8\% and 0.8\%, respectively) milk production and lower (0.3\% and 1.2\%, respectively) protein production than BC animals while the differences between the phenotypes for fat production were small. The b-CN A2 allele was associated with increased production in the Friesians with A2A2 cows producing approximately 2\% more milk, fat and protein than A1A1 cows. The opposite effect was found in Jerseys where A2A2 cows produced 3-4\% less milk, fat, and protein than A1A1 cows. The B allele of k-CN was associated with a 0.6 to 3.5\% increase in production. The b-LG BB phenotypes produced approximately 1.3\% less milk and protein and 1.2\% more fat than the AA phenotypes. The dominance effect was not significant (P<0.05) for any of the protein phenotypes. }, issn = {1176-5283}, author = {Winkelman AM and Wickham BW} } @conference {40823, title = {An attempt to create an {\textquoteright}anoestrous cow{\textquoteright} model by restricting feed allowances in non-lactating cyclic cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {233-235}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {This experiment aimed to characterise the ovarian response to reducing live-weight (LWT) with the view of creating nutritional anoestrus in cyclic cows. The ovaries of 8 non-lactating 3 yr old Friesian cows were ultrasounded daily during 5 synchronised oestrous cycles (Rounds 1 to 5) over 12 months. An initial live-weight of 445 }, issn = {1176-5283}, author = {Burke CR and Verkerk GA and Macmillan KL} } @conference {40851, title = {Brief Communication: Alpaca management in the Central North Island of New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {342-343}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The high South American altiplano is not the ideal environment for alpacas but was forced onto them by the introduction of sheep and cattle to the Inca pastures following the Spanish conquest. In New Zealand they are being farmed in a variety of areas and seem to respond dramatically to our normal farming methods. Warm, humid areas can cause problems with eczema and staggers. Alpacas produce a semi-precious fibre of various colours, which at present is causing processing difficulties in New Zealand due to the small quantities, so we are concentrating on increasing herd numbers. Alpaca management can be closely allied to sheep farming, with the exception of their mating and breeding. They are induced ovulators and can be mated in either pens or paddocks. Pen mating gives better control but is more work, while paddock mating has the disadvantage of prolonging the breeding season. Alpacas will breed at any time of year, but we have found that the autumn suits them best and they are remated two weeks after birthing. Alpaca twins are extremely rare. They are a hardy, easy care animal that will do well on untopdressed native pastures and when run in isolation seldom get internal parasites, but can pick up lice or mites. We are still learning what suits alpacas best, bearing in mind that these are very adaptable animals that do not need alterations to their environment to suit any specific needs.}, issn = {1176-5283}, author = {Nelson ID} } @conference {40821, title = {Brief Communication: Automatic oestrus detection from milking data - a preliminary investigation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {228-229}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The solid fat content of milkfat has a major influence on the hardness of butter produced at dairy factories. The aim of this work was to study the variation in the solid fat content of milkfat from thirty herds in the factory collection area on a single dayto determine the extent of variation in the milk supply. The solid fat content of the milkfat at 10{\textdegree}C varied from 49.6\% to 59.8\% between the individual herds. This variation in the milk from different herds is as large as the entire seasonal change observed in the bulked factory silo milk, indicating significantvariation in the properties of the milkfat within the factory supply on a single day. Low solid fat content at 10{\textdegree}C was correlated with milk of low fat percent (r = 0.78, P< 0.0005) and high protein-to-fat ratio (r = -0.75, P< 0.0005). Though there was substantial variation in the solid fat content within the breeds, milkfat from Friesian herds had a significantly lower solid fat content than milkfat from Jersey herds (mean {\textpm} S.E., 54.4 {\textpm} 0.6 and 57.1 {\textpm} 0.6 respectively, P = 0.004). There appears to be considerable potential for exploitation of the natural variation in the properties of milkfat inherent in the New Zealand dairy herds. }, issn = {1176-5283}, author = {Sherlock RA and Smith LA and Mitchell RS} } @conference {40781, title = {Brief Communication: Binding of nuclear proteins to the bovine alpha- lactalbumin gene promoter}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {68-70}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The production of milk during lactation requires tran-scriptional activation of milk protein genes. This is facili-tated by the binding of nuclear factors to the gene promoter. The DNA binding activity of some of these factors appears to be controlled by lactogenic hormones, although many aspects of this process are not understood. Determining the precise molecular mechanism of transcriptional control and which nuclear factors are involved will facilitate the manipulation of milk composition. Recently, a transcrip-tion factor called Stat5 has been shown to be required for the activation of the rat β-casein gene (Schmitt-Ney et al., 1991), the sheep β-lactoglobulin gene (Burdon et al.,1994) and the rat whey acidic protein gene (Li and Rosen, 1995). This protein is activated during late pregnancy and through-out lactation in the mammary gland of mice (Schmitt-Ney et al.,1992). We have used the Stat5 DNA recognition sequence in this study to investigate the activity of Stat5 in the bovine mammary gland.}, issn = {1176-5283}, author = {Kuys YM and Snell RG and Wheeler TT} } @conference {40775, title = {Brief Communication: Effect of atropine on milk protein composition of dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {51-52}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Milk production by dairy cows and yield of the compo-nents, fat, protein and lactose are closely related to nutritional intake. The individual proteins in milk respond differently to a change in nutritional status, giving rise to significant differ-ences in milk protein composition (DePeeters and Cant, 1992). For instance, Gray and Mackenzie (1987) noted a decrease in α-lactalbumin and increase in serum-derived proteins, serum albumin and immunoglobulin, in animals on restricted pasture for 10 days. Although β-lactoglobulin concentration decreased, the response was not significant. Treatment of concentrate-fed dairy cows with a single injection of atropine caused a similar, though temporary, decrease in milk yield, total protein and α-lactalbumin content of milk (Roets and Peeters, 1981). Changes in other milk proteins were not evaluated. The observed responses arise from the ability of atropine to rapidly and specifically depress plasma amino acids used for milk protein synthesis and provide a means of experimentally manipulat-ing supply of substrates for milk protein synthesis. The present study was designed to evaluate the use of atropine in pasture-fed cows.}, issn = {1176-5283}, author = {Prosser CG and McLaren RD} } @conference {40812, title = {Brief Communication: Effect of dietary vitamin A on plasma carotenoid concentration and fat colour in cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {193-194}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {In two trials using cattle grazing green pasture, daily supplements of 1x106 IU vitamin A decreased plasma carotenoid (PC) concentration by 43- 58\% over 28-31 days. Neither increasing the dose of vitamin A to 2.5 x 106 IU nor continuing the supplement for 83 days further reduced PC concentrations. These decreases in PC concentrations were not accompanied by decreases in carotenoid concentration in the subcutaneous fat or fat colour. This was possibly because PC concentration was still too high to allow a loss of carotenoids from the fat depots. }, issn = {1176-5283}, author = {Knight TW and Death AF and Wyeth TK} } @conference {40859, title = {Brief Communication: Effect of lipids on ram spermatozoal motility}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {365-366}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Lipids from egg yolk, milk and coconut were toxic to ram spermatozoal motility. The toxicity of egg yolk lipid was associated with the neutral lipid fraction. Motility was prolonged in the presence of coconut lipid.}, issn = {1176-5283}, author = {Upreti GC and Hicks K and Oliver JE and Briggs RM and Duganzich DM and Smith JF} } @conference {40774, title = {Brief Communication: Effects of milk stasis and feed withdrawal on capillary exchange capacity in the goat mammary gland}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {49-50}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The lactating mammary gland is critically dependent upon the provision of nutrients and hormonal stimuli from the blood to sustain milk synthesis. This is reflected in the high correlation between mammary arterial blood flow (F) and milk yield (MY). During established lactation in goats, frequent milking with oxytocin results in a higher blood flow to the mammary gland (Prosser and Davis, 1992). Conversely, MY and F decrease during both milk stasis (Stelwagen et al. 1994) and feed withdrawal (Davis and Collier, 1985). It has yet to be determined whether these decreases in the blood supply cause the decreases in MY or are as a result of a decrease in demand for blood by the secretory tissue.}, issn = {1176-5283}, author = {Farr VC and Davis SR and Prosser CG} } @conference {40855, title = {Brief Communication: The effect of inorganic ions on ram sperm motility using Computer Assisted Sperm Analysis (CASA)}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {353-354}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The role of specific inorganic ions in the maintenance of ram sperm motility in a chemically defined ram semen diluent (RSD-1) was examined. A preliminary experiment identified that magnesium was required to maintain motility. Significant treatment and incubation effects were observed for all motility parameters (P<.05). RSD-1 (treatment T1) was modified to provide a series of treatments. Effects measured were the substitution of MgCl2 (T2) or MgSO4 (T3) and the elimination of KH2PO4 (T4) or NaHCO3 (T5). A total of 10 ejaculates were analysed using the Hobson Sperm Tracker (HST) over a period of 7 days. Semen was cooled to 15 C after dilution with treatment diluents and reheated to 38 C after 1 hr and 5 days storage. Motility was measured after incubation at 38 C for 0, 24, and 48 hours. Treatments had a significant (P<0.001) effect on the velocity parameters and the percentage of motile sperm. Treatments T4 and T5 had greatest depression in motility parameters with fresh semen while T5 also had an effect with stored sperm. Substitution of the MgSO4 (T3) reduced the velocity parameters in the fresh semen e.g. mean Curvilinear velocity (VCL) values (}, issn = {1176-5283}, author = {Briggs RM and Upreti GC and Smith JF and Duganzich DM} } @conference {40773, title = {Brief Communication: The effect of somatostatin infusion on milk yield of goats}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {47-48}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Somatostatin is a hormone widely distributed among tissues which, depending upon species, will inhibit growth hormone release from the pituitary gland and modulate the release of insulin from the pancreas (e.g. Davis, 1975; Maglad et al.,1983). The physiological function of somatostatin in rumi-nants is largely unknown. Certainly effects of somatostatin on the function of the gastro-intestinal tract have been reported (Barry et al.,1985). However, somatostatin ap-pears not to modulate basal growth hormone release in ruminants (Davis, 1975). }, issn = {1176-5283}, author = {Davis SR and Farr VC and Myung KH and Prosser CG and Spencer GSG} } @conference {40837, title = {bST: An assessment of potential response for pasture based dairy farms in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {289-291}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Potential response of lactating dairy cows to bovine somatotropin (bST) was estimated ex ante for 12 geographically distinct pastoral regions of New Zealand. The estimation process was as follows. First, seasonal pasture growth data were collected or, where such data were unavailable, seasonal pasture growth was estimated from published climate data using the GROW model. The UDDER model was then used to generate, from the pasture growth information and average regional stocking rate, seasonal pasture mass profiles for an }, issn = {1176-5283}, author = {Ekanayake PMB and Matthew C and Bailey WC} } @conference {40814, title = {The calpain proteolytic system in different types of ovine skeletal muscles and relationship to meat tenderness}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {198-200}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The calpain system is involved in postmortem tenderisation of meat. Muscle type also influences tenderness and aging rate. This study investigated the extent to which differences in the calpain system may account for differences in tenderness. Calpain and calpastatin activities were measured from 12 different ovine muscles. Shear force was determined on muscle aged at 15 C for 1, 2, 3 and 4 days postmortem and ultimate pH measured. Calpastatin, }, issn = {1176-5283}, author = {Singh K and Dobbie PM and Simmons NJ and Bass JJ and Thomson BC and Speck PA} } @conference {40857, title = {Calving performance after embryo transfer-induced twinning - a summary of 30 studies}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {358-361}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Twin calving in beef cows has been proposed as a strategy to increase the biological as well as economic efficiency of beef production. The aim of this paper is to summarise the calving performance of cows induced to calve twins following embryo transfer using data from 30 published studies. The pooled data shows that 45, 28 and 27\% of recipients give birth to either 0, 1 or 2 calves resulting in 82 calves born/100 recipients and 47\% of calving cows producing twins. Overall mean embryo survival rate was only 41\%. Compared with recipients which received in vitro-produced embryos, a higher proportion of recipients that received either a pair of in vivo-derived embryos or a single such embryo in conjunction with AI were pregnant (60 vs 43\%) or produced twin calves (52 vs 39\%). In addition, more calves were born (90 vs 60\%). Considerable variation exists in all parameters, particularly the proportion of number of calves born.}, issn = {1176-5283}, author = {McMillan WH} } @conference {40866, title = {Characterisation of beef cattle breeding industry structure}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {386-389}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The structure of the beef cattle industry, from a breeding viewpoint is characterised by registered herds from which bulls are sold to: other registered breeders, commercial beef cattle farmers and dairy farmers. This project characterised New Zealand}, issn = {1176-5283}, author = {Charteris PL and Garrick DJ} } @conference {40868, title = {A comparison of two methods of castration of post-pubertal beef cattle and their effect on behaviour, growth and ultimate pH}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {394-397}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {This study aimed to evaluate the effect of surgical and immunocastration of post-pubertal beef cattle on their sexual and aggressive behaviour, growth and meat quality. Forty mixed-breed bulls were assigned to one of four treatments (n = 10): steers (S) castrated at 11 months of age, late castrates (LC) surgically castrated at 17 months of age (Day 1), immunocastrates (I) vaccinated against GnRH at 17 months of age (Day 1) and entire bulls (B). Sexual and aggressive behaviour was monitored at monthly intervals and prior to slaughter, animals were weighed and blood sampled fortnightly. All treatments were slaughtered at 22 months of age after which carcass composition and meat quality (pHu) were assessed. Plasma testosterone concentrations declined to the level of steers by Day 14 for late castrates and by Day 28 for immunocastrates and remained lower than for entire bulls through to slaughter. Entire bulls had a heavier hot carcass weight (HCW) than I, LC and S. Immunocastrates were heavier than LC and S. Treatment had no effect on pHu although late castrates tended to have a higher mean pHu than immunocastrates and steers. From Day 0 to slaughter, rates of sexual and aggressive behaviour declined significantly for bulls, late castrates and immunocastrates to be similar to steers. There was a tendency for bulls to show higher levels of both sexual and aggressive behaviour during lairage.}, issn = {1176-5283}, author = {Jago JG and Matthews L and Bass JJ and Knight TW} } @conference {40842, title = {A comparison of unbred and once-bred lamb production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {307-309}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The once-bred lamb (OBL) production system involves mating ewe lambs at 8 months of age to be slaughtered at approximately 15 months of age after rearing a lamb. This study compared the performance of bred ewe lambs (}, issn = {1176-5283}, author = {Johnston JB and Morris ST and Purchas RW and McCutcheon SN and Parker WJ} } @conference {40764, title = {A computationally feasible test day model with separate first and later lactation genetic effects}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {19-21}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {In a two step analysis test day effects were estimated within herd with adjustment for across herd effects and then the adjusted data were analysed across herd. Genetic effects were defined for each of 10 months in milk within first and later lactation and for milk, fat and protein giving 60 traits. The rank of the genetic (co)variance matrix (G) was reduced to 6 such that G retained the information to evaluate the selection objective. A repeatability model allowed for multiple lactations with each lactation, conceptually, expressing all 60 traits, but missing observations for 30 or more. A canonical transformation was applied to create uncorrelated traits. Missing values were replaced by their expectations at each round. Because of the rank reduction, only 6 canonical traits were solved for. This system should make evaluations more stable by removing biases due to genetic differences in persistency and rate of maturity. }, issn = {1176-5283}, author = {Wiggans GR and Goddard ME} } @conference {40760, title = {Dairy cattle breeding in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {8}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The New Zealand dairy industry has undertaken a substantial amount of research and development on the economic, genetic, and reproductive aspects of cattle breeding. Much of this research has been conducted within Livestock Improvement and has not been widely published. The purpose of this contract is to bring together a series of papers which provide a summary of the achievements in cattle breeding and identify challenges and directions for the future. They complement the Livestock Improvement lecture by Dr Michel Georges, in which he discusses the use of markers assisted selection as a potential tool to increase rates of genetic gain. The paper by Spelman et al.,reports the results of the first efforts to identify the contribution that this technology can make in New Zealand{\textquoteright}s dairy cattle breeding schemes. }, issn = {1176-5283}, author = {Wickham B} } @conference {40827, title = {Dairy cow performance on limpograss (Hemarthria altissima)}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {245-250}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Limpograss is a perennial subtropical grass which has the potential to produce a bulk of standing feed (34 t DM/ha/yr) for consumption by cattle during summer. To assess the value of limpograss for lactating dairy cows, two experiments were conducted comparing limpograss and mixed temperate pasture diets. In both experiments a four day adjustment period was allowed before milksolids yield was assessed on three of the following ten days. Forage samples were taken for nutritional value assessment. During March 1994, two groups of six Friesian cows on once a day milking late in lactation were pen fed diets of freshly harvested limpograss (Hemarthria altissima) or temperate pasture at equal intakes of 13.1 }, issn = {1176-5283}, author = {Woods PW and Couchman JN and Clark DA} } @conference {40844, title = {Development of fibre and follicle characteristics related to wool bulk in Perendale sheep over the first year of life}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {314-318}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The pattern of wool fibre and follicle development was monitored for 20 Perendale lambs from lines selected for or against wool bulk. There was no significant difference in characteristics associated with wool bulk between selection lines at birth. These characteristics followed a curvilinear pattern of development with most of the change taking place between birth and 14 weeks of age then reaching a plateau by 35 weeks. The different rate of developmental change for each bulk line meant that by 14 weeks the high line had a greater follicle curvature grade, shorter follicle length, shallower follicle depth, more para-meso cortex and a higher fibre curvature. Together fibre curvature, fibre diameter and fibre diameter standard deviation explained around 70\% of the variation in hogget wool bulk from 25 weeks of age. From these results it is suggested that the potential of a sheep to produce high bulk wool can be assessed using fibre curvature and fibre diameter from 6 months of age which allows hogget mating and/or early culling to be practised.}, issn = {1176-5283}, author = {Dick JL and Sumner RMW} } @conference {40813, title = {Differences in the post mortem kinetics of the calpain system in meat from bulls and steers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {195-197}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {This experiment investigated differences in meat tenderness as defined by shear force between bulls and steers, and how these related to differences in the post mortem kinetics of the components of the calpain system. Strip loins (m. longissimus dorsi) from bulls with acceptable (pH < 5.7) ultimate pHs were compared with strip loins from prime steers. Samples were aged for 1, 3, 7, 13, 24, 48 and 72 hours at 15 C. The activities of calpastatin and (}, issn = {1176-5283}, author = {Thomson BC and Dobbie PM and Simmons NJ and Singh K and Speck PA} } @conference {40819, title = {Dynamic programming applied to the dairy cow replacement decision}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {221-223}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {This research addresses the question }, issn = {1176-5283}, author = {Crequer JG and McArthur ATG} } @conference {40786, title = {The effect of albendazole controlled release capsules and moxidectin injection treatment on faecal egg count and body weight of 18 month old ewes in the autumn}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {87-90}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Sixty 18 month old Romney ewes were drenched orally with ivermectin at twice the recommended dose rate (400}, issn = {1176-5283}, author = {Kempthorne R and Familton AS and McAnulty RW} } @conference {40832, title = {Effect of body covers on the liveweight gain of heifer replacement calves and yearlings, and the liveweight gain and milksolids production of dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {266-269}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Body covers are used on dairy stock in an attempt to increase production by reducing the amount of energy required for thermoregulation. Experiments were undertaken to determine the production response to covering calves, yearlings and cows at several sites representing different climatic conditions of the dairying districts of New Zealand. Calves (n=435) were randomly allocated to covered or uncovered treatments on 5 farms in 1993 (n=249) using PVC covers and 4 farms in 1994 (n=186) using Jute covers. Calves were covered for approximately 6 weeks prior to weaning. The difference in total liveweight gain between the covered and uncovered calves within farms ranged from +2.6 kg (}, issn = {1176-5283}, author = {MacDonald KA and Penno JW} } @conference {40830, title = {Effect of calving liveweight on milk yield and composition and daily dry matter intake in Friesian and Jersey heifers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {260-262}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Milk yield and composition were measured weekly throughout lactation, and daily dry matter intake (DMI) on 7 occasions, for Friesian (n=16) and Jersey (n=16) heifers calving at either high (H) or low (L) liveweights. During the 8 weeks pre-partum, heifers were fed to achieve calving liveweights of 404 (H Friesian), 354 (L Friesian), 334 (H Jersey) and 277 (L Jersey) kg. All heifers were fully fed on pasture as one group for the whole of lactation. Calving liveweight had no effect on average DMI over the season. Average DMI was higher for Friesians than Jerseys while average liveweight- corrected DMI was slightly greater for Jersey than Friesians. Average daily milk yields and yields of lactose were lower for L than H heifers. Solids- corrected milk yields and yields of milkfat and protein were unaffected by calving liveweight, but milkfat \% and protein \% were higher for L than H heifers. The Friesians had higher milk yields, and yields of protein and lactose, but lower milkfat \% and protein \% than Jerseys. No effect of restricted feeding during late pregnancy in heifers was demonstrated on milk solids production in the subsequent lactation.}, issn = {1176-5283}, author = {Mackle TR and Parr CR and Stakelum GK and Bryant AM and Macmillan KL and Auldist MJ} } @conference {40826, title = {Effect of feeding turnips to dairy cows grazing limited amounts of pasture in mid to late lactation on milksolids production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {242-244}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Three groups of 20 cows were allocated to one of three feeding treatments. A control group was offered only a restricted pasture allowance. Treatments groups were offered pasture and turnips at either 4 or 8 kg DM/cow/day. Cows offered 4 kg DM/cow and 8 kg DM/cow of turnips produced 265 g MS/c/day (}, issn = {1176-5283}, author = {Penno JW and Bryant AM and Napper AR and Copeman PJA} } @conference {40784, title = {The effect of Fenbendazole on the immune system of lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {80-83}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Measurement of lymphocyte blastogenesis and antibody production were used to determine the effect of a benzimidazole anthelmintic on the immune response. Both parasitized and parasite-naive (n=12) lambs, 6 months of age, were treated with fenbendazole (5mg/kgBW) and compared with untreated control animals. All animals (n=24) were given bovine virus diarrhoea (BVD) vaccine the day following anthelmintic treatment. Heparinised blood samples were collected 0,3,7,14 and 21 days after the anthelmintic treatments. The entire treatment regime was repeated at Day 28. No effects on immunity were apparent after the initial dosage with fenbendazole. However, peripheral lymphocytes from lambs (parasitized and parasite-naive) collected 14 days after the second administration of fenbendazole treatment, had significantly lower stimulation indices compared to control animals, when cultured in vitro with concanavalin A (Con A) (P<0.01), phytohaemagglutinin (PHA), and lipopolysacchride (LPS)(P<0.05). In addition, stimulation to Con A was depressed 7 days after the second treatment. The primary and secondary humoral responses to BVD vaccination, as measured by serum neutralisation titre, were similar among groups. The repeated use of anthelmintics from the benzimidazole group may interfere with immune responsiveness in young sheep. }, issn = {1176-5283}, author = {Parish SJ and McFarlane RG and Familton AS and Abell TJ} } @conference {40800, title = {Effect of iodine supplementation on milk iodine concentrations and productivity of dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {143-145}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Iodine (I) concentrations in New Zealand pastures are low and may be inadequate to meet the I requirements of lactating dairy cows. A trial was undertaken with 400 cows to determine the effects of a single intra-muscular injection of 2000 mg I (in popyseed oil) given at the beginning of lactation on cow performance. The pasture I concentration ranged between 0.17-0.26 mg I/kg DM during of the trial and the supplement increased serum thyroxine (T4) and milk I concentrations for 76 (P<0.05) and 170 (P<0.01) days respectively. Iodine supplementation did not affect milk yield milk composition or number of services per conception. To increase I status and maintain milk I concentrations at or above 40 }, issn = {1176-5283}, author = {Grace ND and Waghorn GC and Mills AR and Death AF} } @conference {40847, title = {Effect of lamb shearing on fine wool Merino hogget performance}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {328-331}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The effect on hogget productivity and wool processing performance of shearing Merinos for the first time as lambs was investigated. A flock of 200 fine wool Merino lambs were randomly separated into two lines. One line was shorn as lambs in late summer and both lines were shorn the following spring as hoggets. There were no differences in live weight at hogget shearing or in flystrike incidence and internal parasite levels. Total wool production was greater from the twice shorn hoggets compared to those shorn only once, with the hoggets shorn twice producing about 0.4 kg more wool. However the differences in hogget wool quality, processing and product performance when lamb wool was removed and the extra wool production did not cover the discounted wool values due to shorter wool staple length and the extra costs of shearing. At current price relativities justification for first shearing Merinos as lambs must relate to management advantages pertaining to individual properties. }, issn = {1176-5283}, author = {Newman S-AN and Maddever DC and Sumner RMW} } @conference {40824, title = {Effect of nitrogen fertiliser and supplements on pasture production and milksolids yield from dairy farm systems}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {236-238}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Seven farmlets of 6.48 ha grazed by Friesian cows at stocking rates of either 3.24 or 4.48 cows/ha were used to evaluate the effect of high rates of nitrogen fertiliser (N) and rolled maize grain on milksolids (MS) production. Annual applications of 213 and 379 kg N/ha increased annual net herbage accumulation by 3350 and 4650 kg DM/ha respectively. At 3.24 cows/ha extra DM resulted in a three fold increase in pasture conservation, providing silage for use in late lactation, and increasing production by 72 kg MS/cow. The extra pasture reduced the amount of supplement required at 4.48 cows/ha. Offering supplementary feed when cows were over grazing or being under fed resulted in an extra 43g milkfat and 47g milk protein/kg DM at the low stocking rate and 45g milkfat and 36g milk protein/kg DM at the high stocking rate. Responses to extra feed were greatest when used to extend lactation. Increased stocking rates will be necessary to maintain pasture utilisation when large amounts of extra feed are introduced. }, issn = {1176-5283}, author = {Penno JW and Bryant AM and MacDonald KA} } @conference {40843, title = {Effect of selection for early lambing on the testicular diameter of the male offspring}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {310-313}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Testicular size has been linked to reproductive efficiency and changes in testicular size could provide an early indicator for the choice of ram lambs to be used in flocks selecting for out-of-season breeding ability. For 3 years, 20 ram lambs from each of the BV(DL)-ve (earlier lambing) and BV(DL)+ve (later lambing) flocks at Ruakura were monitored for testicular diameter (TD) and liveweight (LWT) from weaning until November the following year. In 1991 and 1992, BV(DL) class and season of birth were confounded while in 1993 both BV(DL) classes were represented in both seasons of birth (Autumn and Spring). At the same age Autumn born BV(DL)-ve rams had larger (P<0.05) TD than did Spring born BV(DL)+ve rams in all years. For the 1993 born lambs, the shape of the TD growth curve was different for each BV(DL) x season of birth sub-class (P<0.001). However, at any single age point the within sub- class variation in TD (rsd = 4.6 mm) was such that no meaningful selection for BV(DL) could be made within rams for that season of birth. Liveweight interacted with TD and this effect was also influenced by the season of birth. These data indicate that while TD is influenced by season of birth, the difference in TD between ram lambs of divergent BV(DL; selection for out- of-season breeding ability) was not sufficient for TD to be a useful parameter for early selection. }, issn = {1176-5283}, author = {Smith JF and Parr J and Duganzich DM} } @conference {40848, title = {The effect of shearing by cover comb or blades on the resistance of sheep to cold, windy and wet conditions}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {332-333}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Four pairs (total 8 sheep) of Romney mixed-age ewes were housed indoors and fed chaffed lucerne hay at a level equivalent to 1.2 times maintenance. Oxygen consumption was measured in two open circuit calorimeter chambers on days -3, -2, 0, 2, 6 and 10 with day 0 being day of shearing. On each measurement day, oxygen consumption was measured under two sets of climatic conditions (cold plus wind, followed by cold plus wind plus rain). Differences in live weight, fleece weight and liveweight gain of the ewes were not statistically significant. The difference in the rate of oxygen consumption (litres/kg0.75/hour) between cover comb and blade shorn-sheep was not significant during the cold+wind conditions. However, when }, issn = {1176-5283}, author = {Burnham DL and Holmes CW and Morris ST and Parker WJ and Kidd RI} } @conference {40780, title = {Effect of Streptococcus uberis infection on milk characteristics of individual quarters}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {65-67}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Composite 24 h milk samples were collected for detailed milk analysis from each quarter of ten cows known to be free of intramammary infection. Milk yield and concentration of lactose and serum albumin (BSA) were significantly higher (P<0.001), and chloride ions significantly lower (P<0.001), in hind compared with fore quarters. Four cows developed clinical intramammary infection when subsequently challenged in the left hind quarter with Streptococcus uberis. For all parameters measured, i.e. protein, lactose, somatic cell count (SCC), BSA and immunoglobulins (IgG), milk from the infected quarter differed significantly from the uninfected quarters. No effect of infection was observed in quarters adjacent to the infected quarter, except for SCC, which increased significantly (P<0.001) in the uninfected hind quarter. Milk proteolytic activity in the infected quarter increased significantly (P<0.001) due to increased conversion of plasmin to plasminogen.}, issn = {1176-5283}, author = {Lacy-Hulbert SJ and Woolford MW and Nicholas G and Stelwagen K} } @conference {40846, title = {Effect of wool length and season of shearing on the propensity of Romney, Coopworth and Perendale wool to yellow}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {324-327}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Propensity of wool to yellow is defined as its yellowness after incubation for 14 days at 40 C and 100\% relative humidity. It was determined for mid-side wool samples from Romney, Coopworth and Perendale ewes shorn in summer and/or winter. All samples had a high propensity to yellow (mean Y-Z after challenge 13.0 SD 3.2). The breed ranking from lowest to highest was Perendale, Romney and Coopworth (12.4, 13.1, 13.6, respectively; SED 0.2). Wool shorn in winter was less susceptible to yellowing than wool shorn in summer (11.7 vs 14.4; SED 0.26) and short wool was less susceptible than long wool (12.0 vs 14.1; SED 0.26). There was a highly significant interaction between wool length and time of shearing. Propensity to yellow of wool sampled at hogget shearing was not a significant predictor of propensity to yellow of the adult fleece wool. The measurement was repeatable between some, but not all, successive shearings of adult ewes. This suggests that the method used may be useful in selecting adults to reduce yellowness by breeding.}, issn = {1176-5283}, author = {Reid TC and Sumner RMW and Sedcole JR and Botica KJ} } @conference {40794, title = {Effects of condensed tannins on animal performance in lambs grazing Yorkshire fog (Holcus lanatus) and annual ryegrass (Lolium multiflorum)}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {118-121}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A comparative study was undertaken in Uruguay from August to early November 1994 to investigate differences in animal performance between lambs rotationally grazing mixed swards of annual ryegrass (Lolium multiflorum) and white clover (Trifolium repens) or Yorkshire fog (Holcus lanatus) and Trifolium repens. The effects of condensed tannins (CT) on lamb production were assessed by twice daily oral administration of polyethylene glycol to half the lambs on each sward combination. Lambs grazing on Yorkshire fog swards had higher clean wool growth (1470 vs 1280 }, issn = {1176-5283}, author = {Montossi F and Hodgson J and Morris ST and Risso DF} } @conference {40825, title = {Effects of feeding silage and extending lactation on the pastoral dairy system}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {239-241}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Short lactation length is one of the main reasons for the low milk yield per cow in New Zealand. This experiment used replicated farmlets to measure the effects of extending the lactation, and feeding extra silage on the dairy farm system. On the 4th April 54 lower yielding cows were dried- off and divided into two equal herds (D). The remaining 64 cows were also divided into two equal herds, and milked for another 54 days (M). Each of the four herds was grazed on a self- contained farmlet, at 2.9 cows/ha. D herds received only grazed pasture (16 kg dry matter (DM)/cow/day allowance), while M herds received pasture (30 kg DM/cow/day allowance) plus silage (5.5 kg DM/cow/day). At the end of the experiment the M system produced 57.7 kg milksolids (fat+protein) per cow, but had lower (P<0.05) average pasture cover (by 584 kg DM/ha) and lower (P<0.001) body condition scores (by 0.33/cow) than the D system. Extra milk can be produced from extra days in milk, but the extra feed required must be planned and monitored very carefully, to prevent losses in body condition and pasture cover. }, issn = {1176-5283}, author = {Pinares C and Holmes CW} } @conference {40867, title = {Effects of post-pubertal castration and diet on growth rate and meat quality of bulls}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {390-393}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {By castrating bulls post-puberty and then finishing before slaughter it may be possible to obtain both the higher growth rate of bulls but the meat quality of steers. Of 50 crossbred bulls, 20 were castrated at 10 months-of age (steers) and 20 castrated at 17 months-of age (castrates). One month after the latter castration, all animals commenced a 100 day finishing period and were slaughtered at the end. Ten steers and 10 castrates were fed a diet of 50\% barley : 50\% silage while the rest grazed brassica crop and pasture. Bulls were 20 kg heavier than steers at post-pubertal castration (388 }, issn = {1176-5283}, author = {Cosgrove GP and Knight TW and Lambert MG and Death AF} } @conference {40799, title = {Effects of potassium on potential difference across the rumen wall and magnesium metabolism in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {138-142}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Several in vitro studies have indicated that the potential difference (p.d.) across the rumen wall is important for magnesium (Mg) absorption and that increases in p.d. as a result of high rumen potassium (K) concentration may reduce Mg transport. The aim of this work was to provide quantitative data on the relationship between p.d. and Mg absorption in the live animal and on diurnal variation in p.d. Twelve rumen cannulated ewes, weighing 45}, issn = {1176-5283}, author = {Wachirapakorn C and Sykes AR and Robson AB} } @conference {40777, title = {Effects of stage of lactation and season on udder development and milk yield in pasture-fed cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {58-60}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Effects of stage of lactation and season on mammary development and milk yield were determined in three herds of lactating Friesian cows (n~25 cows/herd) during June and July 1995. The herds in early, mid or late lactation calved in Apr-95, Jan-95 or Oct-94, respectively. Milk yield, in June, was higher in early and mid than in late lactation (16.1, 15.3 and 11.7 kg/d respectively, P<0.001). In July, yield was highest in early lactation and significantly lower with each successive stage of lactation (14.0, 12.5 and 10.4 kg/d, P<0.02). Yield decreased from June to July (14.4 to 12.3 kg/day, P<0.001) under increasingly severe nutritional/environmental influences. Udder capacity was higher in early and mid lactation than in late (16.1, 16.2 and 14.3 L, P=0.07), and decreased 18\% from June to July (17.1 to 14.0 L, P<0.001). These results suggest that loss of mammary capacity is an important cause of declining milk production due to stage of lactation and season. }, issn = {1176-5283}, author = {Eichler SJ and McFadden TB} } @conference {40763, title = {Estimation of lactation yield from repeated measures of test day yields}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {16-18}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Test day production records were combined into a measure of lactation yield for the purposes of genetic evaluation of lactation production in dairy cattle. The lactation yield estimation adjusts for test day environment, standardises lactation length, takes account of culling and weights test day records according to number of tests, stage of lactation at test and intervals between tests. Any combination of tests can be used allowing for inclusion of records in progress or incomplete lactation in genetic evaluation. }, issn = {1176-5283}, author = {Johnson DL} } @conference {40778, title = {Evaluation of milk EPDs in Angus dams with actual milk production and calf weaning weights}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {61}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Evaluation of milk EPDs in Angus dams with actual milk production and calf weaning weights written By: Worrell MA, Thompson CE, Grimes LW, Skelley GC, Williams RH}, issn = {1176-5283}, author = {Worrell MA and Thompson CE and Grimes LW and Skelley GC and Williams RH} } @conference {40828, title = {Evaluation of the Cornell Net Carbohydrate and Protein System for dairy cows fed pasture-based diets}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {251-254}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {This study evaluated the Cornell Net Carbohydrate and Protein System (CNCPS) for dairy cattle consuming pasture-based diets. Data was obtained from four grazing, and four indoor pasture feeding experiments (23 dietary treatments) with dairy cattle in New Zealand and the United States. ME requirements for maintenance were adjusted to account for grazing activity. The model gave a reasonably good prediction of changes in condition score (R2=0.79, slope not significantly different from 1), energy balance (R2=0.76, slope not significantly different from 1), blood urea nitrogen (BUN) (R2=0.91, underprediction bias of 0.4\%), microbial nitrogen flow (R2=0.83, slope not significantly different from 1), and milk production. The model underpredicted DM intake (R2=0.80, 11\% bias), and overpredicted ruminal pH (R2=0.47, 1.8\% bias). These results indicate that the CNCPS can be used to make realistic predictions of ruminal fermentation and performance of dairy cows offered good quality pasture.}, issn = {1176-5283}, author = {Kolver ES and Barry MC and Penno JW and Muller LD} } @conference {40791, title = {Ewe maternal behaviour score and lamb growth: Ten years on}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {107-109}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Maternal Behaviour Score (MBS) has previously been positively associated with lamb weaning weight. This study further investigated the effects of MBS and other ewe behaviours on the growth rate of 111 Scottish Blackface lambs to weaning. Four variables which had a significant effect on growth rate in a stepwise regression analysis were: birthweight (p<0.05), pre-lambing and early post-lambing ewe liveweights (p<0.001) and MBS (p<0.05). The relationship between MBS and lamb growth rate was not linear. An increase in MBS from 2 to 3 was associated with the greatest increase (10\%) in growth rate. MBS was correlated to the frequency of ewe calling (p<0.01) and ewe head up, alert posture (p<0.01) observed during undisturbed field interactions. These behaviours are used to maintain contact between the ewe and lamb, and are indicators of ewe awareness. Therefore, MBS is a good indicator not only of lamb growth but also of the strength of the pre-weaning ewe-lamb relationship.}, issn = {1176-5283}, author = {O{\textquoteright}Connor CE} } @conference {40864, title = {Factors influencing induced oestrus in the ewe at the start of the breeding season}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {381}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The objectives of this study were to monitor the physiological events associated with decreasing liveweight in Bos indicusheifers and to determine the characteristics which best predicted the onset of nutritional anoestrus. Eleven post-pubertal Brahman heifers received a diet resulting in a liveweight loss of 0.7 kg/day. Changes in ovarian morphology were monitored using daily transrectal ultrasonography. Liveweight was recorded twice weekly. Heifers became anoestrus after 98 {\textpm} 9 days, following a decrease in liveweight of 68.6 {\textpm} 4.9 kg, equivalent to 21.5 {\textpm} 1.5\% of initial weight. At this time, maximum diameters of ovulatory follicles and corpora lutea (CL) had decreased by 16.7 {\textpm} 3.9\% and 23.7 {\textpm} 3.1\%, respectively. Onset of anoestrus was best predicted by liveweight and maximum diameter of CL when expressed as proportions of initial liveweight and size of CL. The percentage decreases in liveweight and maximum diameter of CL to give a 50\% probability of anoestrus were 21.0\% (95\% confidence interval = (17.7, 27.4)) and 23.0\% (16.7, 37.0), respectively.}, issn = {1176-5283}, author = {Fenton LS and Shackell GH and Ramsay ML and Dodds KG and Reid PJ and McLeod BJ} } @conference {40785, title = {Faecal nematode egg counts and facial eczema susceptibility in Romneys}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {84-86}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A study was carried out in two groups of flocks to estimate the relationship between susceptibility to facial eczema (FE) and susceptibility to nematode parasites. Faecal egg count (FEC) data on lambs born in 1989- 92 from 53 sire groups were collected on the Ruakura Romney flocks which have been divergently selected for resistance/susceptibility to FE. In addition, the Romney flocks selected at Rotomahana/Tokanui Stations for resistance/susceptibility to FEC were sampled to provide the converse (i.e. FE data) on lambs born in 1988 and 1989, and representing 43 sires. Faecal samples for FEC were collected from lambs in January and March (separated by an anthelmintic treatment) and the FEC data were analysed using a loge transformation. FE susceptibilities, using the enzyme gamma- glutamyltransferase (GGT) as an indicator, were obtained in the FE flocks at Ruakura after an oral sporidesmin challenge in May, and in the FEC flocks at Tokanui after unintentional field challenge; the GGT data were also analysed using a loge transformation. The weighted average heritabilities of loge GGT and loge (FEC+100) were 0.44}, issn = {1176-5283}, author = {Morris CA and Towers NR and Watson TG and Wheeler M and Amyes NC and Hosking BC} } @conference {40835, title = {A farm level model to aid decisions regarding the feeding of concentrates to dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {280-284}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {In recent years dairy farm consultants in New Zealand and Australia have regularly been asked to provide advice to farmers on whether the feeding of concentrates to lactating cows on pasture diets is likely to be economic. The outcome of such a decision is complicated because its effects on milk production, liveweight change, pasture growth and decay, and herd reproductive performance are influenced by variables pertaining to the particular farm and herd involved. Some responses to concentrate inputs are immediate; others occur in the long term. Information on each response variable was integrated into a manual decision support framework to provide a practical decision aid for consultants and farmers. A spreadsheet template was then developed to reduce calculation time and allow a wider range of feed and herd situations to be evaluated. The total economic benefits, and hence breakeven price for concentrates were found to be heavily dependent on the long term moblisation of liveweight gained, utilisation of extra pasture grown and changes in the herd}, issn = {1176-5283}, author = {Neaves PJ and Parker WJ and Holmes CW} } @conference {40796, title = {Frequency distribution of sward height on pastures grazed by cattle alone or co-grazed with sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {125-129}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Pasture height is increasingly employed in feed planning as a measure of pasture availability. The frequency distribution of pasture height on a ryegrass/white clover pasture grazed by steers has been shown to be a double normal distribution representing }, issn = {1176-5283}, author = {Kitessa SM and Nicol AM} } @conference {40802, title = {Future directions for meat research and development in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {147-150}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {If meat research, from production through to the marketplace, is not adequately funded, then much of the research needed to improve New Zealand}, issn = {1176-5283}, author = {Kirton AH and Purchas RW} } @conference {40805, title = {Genetic improvement of meat quality in sheep and cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {157-162}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Genetic variations in body composition are apparent as differences among breeds, crosses, selected strains and sire groups. Crossbreeding, use of terminal sires and selection within breeds has tended to concentrate on total meat output rather than quality, despite consistent consumer signals against fat. Evidence suggests that, in males selected using live animal ultrasound measurements of fat and muscle depths, about half of the selection pressure available to improve growth rate should be sacrificed in order to maximise economic response through decrease in carcass fat content. Genetic variations in lean/fat partitioning to different regions and muscles of the carcass, and in traits affecting the wider sensory appeal of cooked meat, are also important to the range and consistency of meat products. Indirect live animal indicators are vital to minimising the high cost of progeny testing. Meat product tenderness is one example. Much of the variation is under the control of the calpain system for which genetic differences have been found among breeds and crosses, related families, selection lines, and in strains segregating for major genes and genetic markers (e.g. calpastatin and the CSSM18 and TGLA122 markers of the callipyge gene in sheep). Decreased post mortem tenderness is associated with decreased proteolytic enzyme activity which in some cases is related to increased lean growth rates in the live animals as well. Between and within muscle variations in actin/myosin interactions, lipid, myoglobin contents and solubilities can also give rise to genetic variations in tenderness, meat flavour, colour and the heat gellation properties of myosin. The biochemical basis of these effects suggests useful indicator traits (e.g. LDH and ICDH enzyme activity associations with fibre type, intra-muscular fat and haem iron contents) which are likely to offer innovative genetic solutions to long-term industry competitiveness.}, issn = {1176-5283}, author = {Clarke JN and Morris CA and Speck PA and Upreti GC and Nicoll GB} } @conference {40770, title = {Genetic parameters for fertility traits in seasonal dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {38-41}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Genetic parameters for female fertility traits in New Zealand dairy cattle have been estimated using a data set of herds participating in the Livestock Improvement Sire Proving Scheme. In total, 66294 records of both pure and crossbred Friesian, Jersey and Ayrshire cows in their first lactation were used. The highest heritability estimates were .134, .058, .037, .037, .029 for age at calving (AC), interval from start of mating (STOM) to first mating (SMFM), interval from STOM to conception (SMCO), pregnancy rate at day 21 or 42 after STOM (PR21) or (PR42), respectively. Low heritabilities were obtained for first mating to conception (FMCO), calving interval (CI) and number of services (NS) (<.017). Genetic correlations between CI and either SMFM or SMCO where high (.920 or .957). Genetic correlation between SMCO and PR21 or PR42 is close to one. Therefore the later three traits are identical from the selection point of view. For AC, genetic and phenotypic correlations with milk production traits were high and unfavourable. Antagonistic genetic correlations also existed between milk yield and the fertility traits and between SMFM, SMCO, FMCO or NS and fat or protein yield. The unfavourable genetic correlations between milk production and fertility traits strongly suggest that fertility performance should be incorporated into the breeding objectives of New Zealand dairy cattle. Based on their heritability estimates, their genetic coefficients of variation and their genetic correlations with production and other fertility traits, it is recommended that SMFM and PR21 (or its more easily obtainable equivalent trait 2-to-24-day non-return rate, 2-24NRR) should be used as selection criteria. In addition, the incidence of use of treatment programmes for overcoming fertility problems, such as induction of calving and anoestrus treatment, should also be incorporated into the selection index.}, issn = {1176-5283}, author = {Grosshans T and Xu ZZ and Burton LJ and Johnson DL} } @conference {40815, title = {Growth and carcass characteristics of lambs sired by Texel, Oxford Down and Suffolk rams}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {201-204}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Three hundred and twelve lambs (160 ram, 152 ewe) sired by Texel (n = 118), Oxford Down (n = 94) and Suffolk (n = 100) rams and out of Romney ewes were grazed at Poukawa Research Station, Hastings, to evaluate comparative growth characteristics and carcass composition. Lambs were sourced from a range of commercial properties and sires. Representative samples from each breed and sex were slaughtered after 84, 112 and 145 days on trial. Fasted liveweight gain were significantly (P<0.001) higher for Suffolk-cross (107 g/d) and Oxford Down-cross (101 g/d) lambs than for Texel-cross lambs (84 g/d). At a constant hot carcass weight (HCW) of 19.2 kg, Texel-cross lambs had a significantly (P<0.01) lower GR (mean 12.0 mm) than Suffolk-cross (14.1 mm) and Oxford Down-cross (13.3 mm) lambs. Carcasses were boned to a commercial specification which maximised the removal of bone and fat. At a carcass weight (CW) of 19.2 kg Texel-cross lambs had a significantly (P<0.001) higher saleable meat yield (SMY; 647 g/kg CW) than Suffolk-cross (634 g/kg) and Oxford Down-cross (629 g/kg) lambs. Texel-cross and Oxford Down-cross lambs had a higher proportion of the SMY in high value cuts (HVC) than Suffolk-cross lambs. At a CW of 19.2 kg Suffolk-cross lambs (395 g HVC/kg SMY) had a lower yield than Texel-cross (402 g/kg; P<0.001) and Oxford Down-cross (400 g/kg; P<0.05) lambs. There was no breed by sex interaction, but ewe lambs yielded a significantly higher proportion of HVC in their SMY (402 v 396 g/kg for ewe and ram lambs respectively, P<0.001). At a CW of 19.2 kg eye muscle area was significantly higher (P<0.001) for Texel-cross lambs (13.5 cm2) than for Suffolk-cross and Oxford Down- cross (both 12.7 cm2) lambs, with no sex differences.}, issn = {1176-5283}, author = {Cruickshank GJ and Muir PD and MacLean KS and Goodger TM and Hickson C} } @conference {40790, title = {Heart rate response as a measure of stress and welfare in cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {103-106}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Problems exist in welfare quantification of stressors due to variation in animal responses. A theory, based on adaptation to repeated exposure of a stressor, is proposed for objective assessment of welfare. Cattle of three ages were exposed repeatedly to transport, or aspects of transport. Cattle aged 6 weeks showed a declining tachycardic response to repeated transport (p<0.05). Cattle aged 3-6 months showed no consistent pattern of heart rate response to transport, although bradycardia was observed in some animals. Bradycardia was also observed in 2 year old bulls, the incidence of which declined with repeat exposure to trailer loading. Heart rate decreased over transport in bulls unfamiliar with trailer loading (p<0.05), while no change in heart rate was seen in bulls familiar with a trailer.}, issn = {1176-5283}, author = {Jacobson LH and Cook CJ} } @conference {40820, title = {Herd-to-herd variations in the properties of milkfat}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {224-227}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The solid fat content of milkfat has a major influence on the hardness of butter produced at dairy factories. The aim of this work was to study the variation in the solid fat content of milkfat from thirty herds in the factory collection area on a single day to determine the extent of variation in the milk supply. The solid fat content of the milkfat at 10 C varied from 49.6\% to 59.8\% between the individual herds. This variation in the milk from different herds is as large as the entire seasonal change observed in the bulked factory silo milk, indicating significant variation in the properties of the milkfat within the factory supply on a single day. Low solid fat content at 10 C was correlated with milk of low fat percent (r = 0.78, P< 0.0005) and high protein-to-fat ratio (r = -0.75, P< 0.0005). Though there was substantial variation in the solid fat content within the breeds, milkfat from Friesian herds had a significantly lower solid fat content than milkfat from Jersey herds (mean }, issn = {1176-5283}, author = {MacGibbon AKH} } @conference {40822, title = {Hormonal induction of oestrus during the early postpartum period and the subsequent effects of nutrition on ovarian activity in dairy heifers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {230-232}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Our working hypothesis was that a significant period of severe underfeeding of dairy heifers during early lactation would not prevent the continuation of normal length oestrous cycles following hormonal induction of oestrus and ovulation in the early postpartum period (pp; 26.0 ( 0.7 d pp). Each of 16 Friesians (F) and 15 Jerseys (J) was treated with a CIDR device for 5 days, with one injection of prostaglandin-F2a the day before device removal and another injection 1.0 mg oestradiol benzoate 24 h after removal. The feed allowances of 8 F and 7 J heifers were reduced over the following 3 oestrous cycles, to a level where live-weights and milk yields were depressed finally by up to 15\% and 36\%, respectively, compared to fully fed contemporaries. Ovarian ultrasonography and monitoring of concentrations of milk progesterone (mP4) during the 1st (Cyc 1) and 3rd (Cyc 3) oestrous cycles showed that 3 Fs (1 FH and 2 FL) did not respond to initial treatment, and remained anovulatory throughout. Another 3 heifers (2 FL and 1 JL) became anovulatory after an initial positive response. The size of the first dominant follicle (DF1) and concentrations of mP4 were reduced by restricted feeding, but only during Cyc 3. This study has shown that a hormonal treatment can induce oestrus and ovulation in the majority of heifers which have been calved between 20 and 30 days. Subsequent restrictions in feeding level may convert some cycling heifers into an anoestrous state, although most will continue to cycle.}, issn = {1176-5283}, author = {Burke CR and Macmillan KL and Verkerk GA} } @conference {40833, title = {Improving the efficiency of pasture-based dairy production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {270-275}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {New Zealand dairy farmers have not achieved the increases in milk production that parallel those of other countries and this has led to a re- evaluation of the opportunities to use feed inputs to complement pasture diets for dairy production. An improved understanding of the chemical composition of pastures, a re-examination of pasture growth dynamics, and recent experimental evidence and farmer experience suggests that there is potential to increase milk production from pasture through strategic inputs of feeds to increase dry matter intake and improve the nutrient balance of the cow}, issn = {1176-5283}, author = {Lean IJ and Parker WJ and Kellaway RC} } @conference {40789, title = {Influence of different proportions of Lotus corniculatus in the diet of lambs on dags, flystrike and animal performance}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {99-102}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The relationship was investigated between the number of days each fortnight spent grazing Lotus corniculatus (lotus) or ryegrass/white clover and dags, flystrike and growth rates in lambs. Lambs which grazed lotus for 7 or more days each fortnight had significantly fewer dags (86-113g) and significantly higher live-weight gains (160-104 g/day) than lambs grazed on ryegrass/white clover (154g, P<0.01 and 73g/day, P<0.05 for dags and live- weight gain respectively). Lambs which grazed lotus continuously had significantly higher live-weight gains than lambs which grazed lotus for 7 or less days each fortnight. Flystrike was positively correlated with dags although this was less obvious over time-period 1 when the incidence of flystrike was low. The incidence of flystrike differed significantly between treatment groups ((2 P<0.001), ranging from 36\% of lambs struck in the all ryegrass/white clover groups to 7\% in the all lotus groups. Wool growth, faecal dry matter content and faecal nematode egg count (FEC) did not differ between treatments. These results confirm the potential of lotus as a tool in the management of dags and flystrike but indicate that lambs will need to be grazed on lotus for 7 or more days each fortnight in order to realise significant benefits. }, issn = {1176-5283}, author = {Leathwick DM and Atkinson DS} } @conference {40793, title = {Influence of level of feeding and stage of lactation on proteolytic activity in bovine milk}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {114-117}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Using a Latin square cross-over design, twelve sets of identical Friesian or Friesian x Jersey twin cows during spring (early lactation: 42 }, issn = {1176-5283}, author = {Nicholas GD and Prosser CG and Stelwagen K and Mackle TR} } @conference {40798, title = {Magnesium metabolism in sheep subjected to sodium or water loading}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {133-137}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = { Six rumen-cannulated ewes, averaging 48}, issn = {1176-5283}, author = {Wachirapakorn C and Sykes AR and Robson AB} } @conference {40771, title = {Manipulation of gene expression in transgenic mice using ribozymes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {42-44}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {This study describes the creation and analysis of transgenic mice carrying a ribozyme or RNA enzyme that specifically targets the bovine a- lactalbumin (a-lac) mRNA transcript. Using a MMTV-LTR promoter-based construct, mammary specific high-level expression of a bovine a-lac- targeted ribozyme was obtained in three out of twelve lines of transgenic mice created. When crossed with mice transgenic for the bovine a-lac gene (0.4 mg of a-lac.ml-1 of milk), expression of the ribozyme resulted in a reduction in the levels of the target mRNA to 50\% of that observed in the non-ribozyme transgenic littermate controls. This activity was specific to the bovine a-lac transcript as no reduction in the levels of the endogenous murine a-lac mRNA was observed. These results demonstrate the feasibility of ribozyme-mediated down-regulation of highly-expressed transcripts in transgenic animals. }, issn = {1176-5283}, author = {L{\textquoteright}Huillier PJ and Vilotte JL} } @conference {40782, title = {Measurement of cell death by in situ end labelling of ruminant mammary gland tissue}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {71-76}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Apoptosis was examined by in situ end labelling (ISEL) of DNA in ewe and cow mammary sections representing the cycle of mammary development, lactation and regression. Labelled nuclei, identifying apoptotic dying cells, were found in tissues from all developmental stages. Generally, apoptosis was low in tissue from virgin animals, moderate in 3 and low in 2 week udders from prepartum ewes and mid pregnant cows, moderate to high in udders from 1 week post partum ewe udders, moderate to low in lactating ewes and cows and slightly higher in involuting ewe and cow udders. Apoptosis was also generally higher in alveoli in stasis than in lactating alveoli. A dramatic finding was that there was intense labelling with both 35S and DIG in the lumenal contents of some alveoli in stasis/involution particularly with animals in later lactation. This suggested that there was a significant amount of ragged DNA ends in the lumen of these alveoli.}, issn = {1176-5283}, author = {Molenaar AJ and Wilkins RJ and Davis SR} } @conference {40817, title = {Measuring body composition by fast neutron activation analysis}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {212-215}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The recent availability of a small compact sealed tube neutron generator, incorporating an associated-particle alpha detector, makes it feasible to measure the concentrations of C, N and O in the body with a very low dose of ionising radiation. We describe this new technique and the equipment needed to use it for measuring body composition. Calibration data from a prototype instrument relate the counts of gamma rays due to C, N \& O from phantoms to the number of incident 14 MeV neutrons and phantom mass. Applying the technique to one 29 kg Romney wether hogget, we estimated it contained 0.69 kg N, 5.52 kg C and 16.5 kg O. These results indicate that the technique holds promise for monitoring the body composition of paediatric and malnourished patients and for measuring the body composition of young experimental animals such as goats, pigs or sheep.}, issn = {1176-5283}, author = {Wolff JE and Mitra S and Garrett R and Webb PA} } @conference {40797, title = {The metabolic cost of hepatic ammonia detoxification}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {130-132}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The quantity of ammonia removed from portal blood by the ovine liver was measured using four sheep prepared with in-dwelling catheters in the hepatic region and fed either lucerne pellets (L) or white clover (WC) at 900 gDM/day. Following blood sampling, plasma ammonia and oxygen concentrations were determined. The portal ammonia concentration and flow were significantly (P<0.01) affected by the diet (304 and 646 }, issn = {1176-5283}, author = {Greaney KB and Reynolds GW and Ulyatt MJ and MacKenzie DDS and Harris PM} } @conference {40829, title = {Microbial protein synthesis and milk production in cows offered pasture diets differing in non-structural carbohydrate content}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {255-259}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The effect on ruminal fermentation and milk production of increasing the proportion of non-structural carbohydrate (NSC) in a pasture diet was investigated in early (Trial 1) and late (Trial 2) lactation. Twenty four cows in Trial 1 and 15 cows in Trial 2 were offered pasture (P), 85\% P plus 15\% protein/NSC mixture (PR), and P+10\% (Trial 1) or P+15\% (Trial 2) NSC (PE) in a latin square design. All diets were isonitrogenous and P and PR were isoenergetic. PE but not PR increased microbial protein synthesis and decreased rumen ammonia and milk urea levels compared to P in both trials. In Trial 1, neither PE nor PR increased milk yield or milk solids output compared to P. Nitrogen but not dry matter digestibility was reduced on PR and PE compared to P. Ruminal degradation of casein, but not of pasture, was increased on PR and PE compared to P. In Trial 2 the milk yields of cows offered PE and PR were greater than those offered P, and greater on PE than PR. Increasing the ratio of carbohydrate to protein was more effective in improving nitrogen utilisation in the rumen than was increasing the proportion of NSC.}, issn = {1176-5283}, author = {Carruthers VR and Neil PG and Dalley DE} } @conference {40783, title = {Milk cortisol concentrations as an indicator of stress in lactating dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {77-79}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The aim of this study was to compare cortisol concentrations in plasma (PCC) and milk (MCC) following administration of exogenous ACTH1-24 or activation of the hypothalamo-pituitary-adrenal axis by a stressor (transport) in cows. Fifteen cows in mid-lactation were assigned to treatments with ACTH1-24 (0.05 mg Synacthen}, issn = {1176-5283}, author = {Verkerk GA and Phipps AM and Matthews LR} } @conference {40838, title = {Milk production from pastures and pasture silage with different levels of endophyte infection}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {292-296}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Perennial ryegrass (Lolium perenne L.) pastures in New Zealand contain the fungal endophyte (Acremonium lolii). This association produces a range of toxins; some, such as lolitrem B and ergovaline have been associated with ryegrass staggers, decreased serum prolactin, heat stress and decreased milk yield. Grazing trials with lactating cows have given equivocal results in terms of milksolids yield. Two experiments examined the effects on autumn milk production of supplementing cows grazing pasture with grass and grass/clover silages containing different endophyte concentrations on autumn milk production. Forty cows were used in a 2 x 2 factorial experiment with low (L) and high (H) levels of endophyte in both pasture and silage. In Experiment 1 (28 March - 6 April 1995) cows were grazing clover free pastures and supplemented with either L or H endophyte grass silage. In Experiment 2 (7-12 April 1995) cows were grazing pastures containing about 17-25\% white clover and supplemented with either L or H endophyte grass/clover silage. At the first milk sampling three days after treatments started in Experiment 1, milk yield from cows given L pastures was 6.9\% higher than from those grazing H endophyte pastures (P=0.006), and 4.1\% more when L rather than H endophyte silages were given (P=0.10). These effects were additive so the cows fed L endophyte silage and L endophyte pasture produced 11.3\% more than those fed H silage and H pasture (P=0.002). The effect of pasture endophyte on milk yield was still evident after seven and ten days of treatment, with 10.3\% more milk from L than from H endophyte pastures (P=0.01). Milk protein yields paralleled milk yields after seven and ten days but there was an endophyte x silage interaction (P=0.05) for milkfat yield and protein and fat yields were not effected by treatment. In Experiment 2 when clover was included in the diet there were no significant effects from either pasture or silage endophyte status on any milk yield components. A comparison of milksolids yield from Experiment 1 and Experiment 2 shows that changing to diets containing white clover increased milksolids by 6.4, 13.9 and 21.9\% for the L/L, L/H and H/L pasture/silage combinations, respectively, but only increased milksolids by 2.7\% for the H/H pasture/silage combination. We conclude that endophyte in both pasture and pasture silage can have a transitory effect on milk and protein yield during the autumn and the nutritional benefits of white clover for increasing milksolids was much reduced by endophyte in both pasture and silage diets. }, issn = {1176-5283}, author = {Clark DA and Thom ER and Waugh CD} } @conference {40834, title = {Nitrogen application to dairy pasture - the effect of rate and timing of spring nitrogen applications on the concentration of pasture nutrients}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {276-279}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Nitrogen (N) fertiliser was applied to ryegrass/white clover dairy pasture in late winter/early spring. Four rates of N (0, 20, 40, 80 kg N as urea) were applied to pregrazed and premown pasture with a residual herbage mass of 1000 kgDM/ha-1 (stubble height of 1.5 cm). Samples were collected from separate 2m2 plots 2, 4, 6 and 8 weeks after N application to detect nutrient changes over time from N appli}, issn = {1176-5283}, author = {Moller S and Edwards NJ and Parker WJ and Hodgson J and Wilson GF} } @conference {40779, title = {Oestrogenic effects on in vitro co-culture of mammary explants and epithelial cells}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {62-64}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Mechanisms of oestrogen stimulation of mammary development were examined using ewe lambs treated with oestradiol (0.1mg/kg BW/day for 7 days; n=5) or controls (n=5). Mammary explants were incubated with [3H]- thymidine to determine effects of oestrogen on epithelial cell proliferation. Also, explants of mammary stroma and parenchyma were co-cultured with a mammary epithelial cell line (MAC-T) to determine the ability of the explants to stimulate MAC-T growth. Oestrogen increased proliferation of ewe mammary epithelial cells (P < 0.02). In co-cultures, addition of mammary explants increased growth of MAC-T cells (P < 0.01), but there was no effect or interaction of tissue type (stroma vs. parenchyma) or oestrogen (P > 0.10). Proliferation of mammary explants was negatively correlated with growth of MAC-T cells in co-cultures (r = -0.41; P < 0.07). These results confirm the importance of oestrogen and mammary stroma in regulating mammary epithelial proliferation but fail to show a requirement for mammary stroma to mediate oestrogenic effects on epithelial cells. }, issn = {1176-5283}, author = {Ellis S and McFadden TB and Akers RM} } @conference {40845, title = {Optimising of the challenge test for the susceptibility of wool to yellow discolouration}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {319-323}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The pattern of wool fibre and follicle development was monitored for 20 Perendale lambs from lines selected for or against wool bulk. There was no significant difference in characteristics associated with wool bulk between selection lines at birth. These characteristics followed a curvilinear pattern of development with most of the change taking place between birth and 14 weeks of age then reaching a plateau by 35 weeks. The different rate of developmental change for each bulk line meant that by 14 weeks the high line had a greater follicle curvature grade, shorter follicle length, shallower follicle depth, more para-meso cortex and a higher fibre curvature. Together fibre curvature, fibre diameter and fibre diameter standard deviation explained around 70\% of the variation in hogget wool bulk from 25 weeks of age. From these results it is suggested that the potential of a sheep to producehigh bulk wool can be assessed using fibre curvature and fibre diameter from 6 months of age which allows hogget mating and/or early culling to be practised.}, issn = {1176-5283}, author = {Aliaga JL and Sanderson RH and Maher AP and Reid TC} } @conference {40861, title = {Ovarian follicle development in the red deer hind}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {370-372}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Ovaries were recovered either 0, 12, 24 or 36 hours or 10 days after CIDR withdrawal, from 25 hinds in which oestrus had been synchronised. All follicles > 2 mm diameter were dissected free of stromal tissue and their health assessed on the basis of oocyte and theca condition, follicular fluid oestradiol content, granulosa cell numbers and oestradiol synthesis. Hinds had an average of 26.6 + 3.45 follicles > 2 mm, of which about half were healthy and 1-3 were oestrogenic. Every animal had at least 1 healthy follicle > 7.5 mm diameter. Over the follicular phase, the percentage of healthy follicles ranged from 46-66\%, but this did not change significantly with time. Neither did the mean diameter of the largest oestrogenic follicle change over the follicular phase. In summary, the total number of antral follicles varied widely, but every hind had at least one large healthy follicle present, irrespective of stage of the oestrous cycle.}, issn = {1176-5283}, author = {McLeod BJ and Meikle LM and Heath DA and McNatty KP and Fisher MW and Whaanga AJ} } @conference {40858, title = {Partial failure of multiple ovulations - a question of uterine efficiency or embryo quality?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {362-364}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Amongst individuals that produce multiple ovulations, and conceive, a variable proportion fail to deliver all potential offspring at term. This source of reproductive inefficiency has been termed partial failure of multiple ovulation (PFMO). In the case of twin ovulators, PFMO is manifest as single births. Most reports in the literature have attributed PFMO to uterine capacity or efficiency factors. An alternative model is proposed, in which it is assumed that a given reproductive outcome is determined by independent binomial effects of embryos and uterine/maternal factors. Using this model, it can be demonstrated that PFMO in twin ovulators can only occur because one of the two embryos is not competent to survive - that is, the uterine/maternal component plays no role in determining variation in PFMO. It follows that in pregnant farm animals with twin ovulations 100\% twin births is possible, but is only constrained by low embryo quality. All published data examined to date in sheep cattle and goats are consistent with this alternative model.}, issn = {1176-5283}, author = {McMillan WH} } @conference {40853, title = {Patterns of oestrus vary with different forms of synchrony}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {347-349}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The original objective of a trial conducted in 3 herds of Friesian heifers was to compare pregnancy rates obtained when each animal was synchronised and then inseminated at about 50 h after removal of a subcutaneous ear implant (CrestarTM) or an intravaginal device (GenermateTM). Because most of the heifers in the CrestarTM group were in oestrus before any of the herdmates treated with the GenermateTM system, the CrestarTM treated heifers were inseminated at either 28 h or 50 h after implant removal. Over the 3 herds, 64\% of 153 heifers treated with Crestar were in oestrus by 28 h after implant removal compared to 7\% of their GenermateTM treated (n=155) herdmates (P<0.01). The average pregnancy rate to first insemination of 56.3\% was similar for both synchrony treatments, and for the two insemination times in CrestarTM treated heifers. The earlier onset of oestrus in heifers treated using the CrestarTM system was possibly associated either with persistent and dominant ovarian follicles, or to the injected oestradiol valerate producing behavioural symptoms of oestrus. Nonetheless, inseminating heifers with a shortened interval to oestrus at 28 h rather than 50 h after implant removal may avoid reductions in pregnancy rate which occur with inseminations made after the end of oestrus, or with heifers which ovulate a persistent dominant follicle. }, issn = {1176-5283}, author = {Macmillan KL and Taufa VK and Morris GR} } @conference {40759, title = {Perspectives for marker assisted selection in dairy cattle breeding - Livestock Improvement Corporation Lecture}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {5-7}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Animal breeders have been manipulating genes for cen-turies, in the sense that by selecting the best performing individuals as the parents for the next generation, they have increased the frequency of favourable alleles and concomi-tantly decreased the frequency of unfavourable alleles at genetic loci influencing the traits of interest. With the intro-duction, in the fifties, of complex biometrical methods to estimate breeding values from own performances and per-formances of relatives, so-called {\textquotedblleft}mass selection{\textquotedblright} has ma-tured into an extremely powerful methodology. Modern breeding programs are largely responsible for the dramatic increase in the efficiency of livestock production that society has witnessed during the second half of this century.}, issn = {1176-5283}, author = {Georges M} } @conference {40869, title = {Plasma carotenoid concentrations early in life can be used as a selection criterion for fat colour in heifers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {398-399}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Plasma carotenoid (PC) concentrations were measured at 2-5 month intervals in 20 Hereford x Jersey (HJ) and 20 Hereford x Friesian (HF) once bred heifers from 10-35 months-of-age. Half of the heifers were slaughtered at 31 months-of-age and the rest at 35 months-of-age. The colour of the subcutaneous and intermuscular fat was measured using a chromameter and c* values were calculated. Subcutaneous and intermuscular fats in HJ heifers were yellower (i.e. they had higher c* values) than in HF heifers. Regression equations that included breed, date of slaughter and PC concentrations at 10-12 months-of-age, accounted for 56\% of the variation in c* values for subcutaneous fat and 40\% of the variation in c* values for intermuscular fat (P<0.001). }, issn = {1176-5283}, author = {Death AF and Knight TW and Purchas RW and Morris ST and Burnham DL} } @conference {40810, title = {Postmortem changes in pH and shear force in three commercial bull beef cuts}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {184-186}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {This experiment investigated the differences between fillet, strip loin and rump cuts obtained from carcasses of pasture-fed bulls. Four samples of each cut were collected on two different occasions and aged at 15 C for 2, 24, 48 ,72 and 120 hours. The pH of the fillet and rump cuts did not change post-slaughter. The pH of the strip loin was higher at slaughter but declined over time and by 48 hrs post-slaughter there were no differences in the pH value of the three cuts. Shear force was determined using a MIRINZ tenderometer. The fillet had the lowest shear force and the rump cut had the highest. There were no differences in the activities of the components of the calpain system at 2 hours post-slaughter. These results suggest that the differences in meat quality and particularly ultimate tenderness, between the three cuts were not due to differences in the activities of the components of the calpain system or pH }, issn = {1176-5283}, author = {Thomson BC and Dobbie PM and Singh K and Speck PA} } @conference {40761, title = {Potential for profitable use of DNA markers in the New Zealand Dairy Industry}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {9-11}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = { Annual genetic advance in merit of dairy cattle can be assessed from selection in four pathways: Bulls to breed Bulls (BB); Cows to breed Bulls (CB); Bulls to breed Cows (BC); and Cows to breed Cows. It is usually assumed that breeding merit is determined by actions of a very large number of genes, each having a small effect (infinitesimal model of inheritance). In practice, the number may be finite, with a few genes (known as QTLs) having large effects. DNA technologies allow young animals to be tested for particular QTLs using markers. Benefits of marker assisted selection were calculated for one additive QTL over a range of sizes (allele values of 0.25, 0.38, or 0.5 genetic s.d.) and initial gene frequencies (0.01, 0.10, 0.35). Testing was conducted in the BB, BC and CB pathways. Strategies were compared using the Net Present Value of the stream of productive benefits less costs for a 30 year horizon, assuming one genetic s.d. is worth $160. Superior rates of advance were sometimes achieved at greater cost than benefits. At a cost of $10 per genotype assessment it was never profitable to genotype small QTLs. The largest QTL could be profitably used to screen young bulls before progeny testing except at the lowest starting frequency. In some circumstances, selection for a QTL resulted in improved medium term response but reduced long-term response. Knowledge of the size and frequency of QTLs and a pre-defined time horizon will be essential to discriminate between profitable and costly applications of this technology. }, issn = {1176-5283}, author = {Garrick DJ and Spelman RJ} } @conference {40863, title = {Predicting the onset of nutritional anoestrus in Brahman heifers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {378-380}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The objectives of this study were to monitor the physiological events associated with decreasing liveweight in Bos indicus heifers and to determine the characteristics which best predicted the onset of nutritional anoestrus. Eleven post-pubertal Brahman heifers received a diet resulting in a liveweight loss of 0.7 kg/day. Changes in ovarian morphology were monitored using daily transrectal ultrasonography. Liveweight was recorded twice weekly. Heifers became anoestrus after 98 }, issn = {1176-5283}, author = {Rhodes FM} } @conference {40816, title = {Prediction of carcass tissue weight in vivo using live weight, ultrasound or X-ray CT measurements}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {205-211}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Twenty-one Dorset Down ewe hoggets (49.4kg body weight, 9months old) were scanned by ultrasound and X-ray computer tomography (CT). Total carcass tissue (fat, muscle and bone) weights were assessed by the Cavalieri procedure from 16-18 CT slices per animal. Additional CT slices were taken at four anatomical reference sites; 7th thoracic (TV7), 2nd lumbar and 5th lumbar vertebrae (LV5), and mid-shaft of the femur. Subcutaneous fat depth and muscle depth were assessed over the last rib using ultrasound. Body weight, ultrasound measurements and reference slice carcass tissue areas were used to predict total carcass tissue weights by multiple regression techniques. In combination with BW, single CT slices predicted tissue weight more accurately than ultrasound measurements with BW for fat (R2=72-84\% vs. 63\%) but not for muscle (R2=79-87\% vs. 83\%) or bone (R2=62-66\% vs. 65\%). The best combination of two CT slices was TV7 \& LV5. In combination with BW these improved prediction accuracy further (fat, R2=92\%, muscle, R2=91\%, bone, R2=71\%). It is possible that data from a single CT slice predict carcass tissue weight less accurately than expected due to anatomical registration errors despite CT producing better quality images than ultrasound. These errors are attributed to scanning protocol constraints for CT equipment. Two or more CT slices need to be scanned in order to predict tissue weight more accurately than ultrasound.}, issn = {1176-5283}, author = {Young MJ and Nsoso SJ and Logan CM and Beatson PR} } @conference {40808, title = {Processing for meat quality}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {172-175}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The factors which constitute quality of meat will vary according to its end use. In this sense, quality can be defined as }, issn = {1176-5283}, author = {Chrystall BB and Daly CC} } @conference {40818, title = {Profitability of rotational crossbreeding programmes in commercial dairy herds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {216-220}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Dairy farm profitability can be increased through the use of superior cows in the lactating herd. Genetic superiority is determined by additive genetic effects and heterosis (present in crossbred animals). Profitability is the difference between income (sale of milk, bobby and salvage animals) and costs (related to the number of cows in the herd and the land area farmed). At comparable production, bigger cows consume more feed reducing their profitability per unit feed consumed. Previous studies have identified the high productivity of first-cross cows comprising Holstein- Friesian (F) and Jersey (J) breeds. In a self-replacing herd, first-cross (F1) animals will not be continuously available unless some straightbred animals are maintained. One approach for exploiting heterosis in a self-replacing herd, is to make use of rotational crossbreeding. This paper reports profitabilities of some rotational crossbreeding programs in comparison to farming straightbred dairy animals. A model was used to estimate on an annual basis, the nutritional, biological and economic performance of whole herds consuming 12,000 kg dry matter per ha. Expected performances for straight- and cross-bred cows comprising F, J and Ayrshire (A) breeds, were obtained using estimates of breed and heterosis effects derived from Livestock Improvement}, issn = {1176-5283}, author = {Lopez-Villalobos N and Garrick DJ} } @conference {40787, title = {Progress on genetic studies of resilience to nematode parasites in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {91-93}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Recent studies on 3- to 7-month-old lambs have shown that there is genetic variation in the ability to withstand the effects of roundworm challenge and thus maintain acceptable performance (high growth, low dags) when left undrenched for extended periods. This trait is generally referred to as resilience. The heritability of resilience has proved to be low (three years}, issn = {1176-5283}, author = {Morris CA and Bisset SA} } @conference {40856, title = {Prospects for overcoming the physiological limits of dairy cow fertility}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {355-357}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Conception rates to a single first insemination in cycling dairy cows often range between 55\% and 75\% . This paper outlines the physiological processes that define this outcome and where possible gains could be made. While herd management issues do influence the outcome of a reproduction progamme quite significantly, the main impetus of this review is to identify some opportunities that could raise the threshold level of fertility in New Zealand dairy herds.}, issn = {1176-5283}, author = {Vishwanath R and Xu ZZ and Macmillan KL} } @conference {40804, title = {Proteases and meat quality}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {153-156}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Consumers judge the quality of meat at the point of sale on colour, visible fat content and odour. However, on eating meat, characteristics such as juiciness, flavour and texture also assume importance. Supermarket surveys of customer preferences have indicated that tenderness is the single most important meat quality characteristic that in-fluences whether consumers are repeat buyers. In New Zealand, the industry standard for tenderness is that shear force must be less than 11 kg F for exported meat. The meat industry recognises, however, that 11 kg F is the upper limit for shear force and that for discerning markets, tenderness values of <5 kg F are required if the markets are to be retained or improved.}, issn = {1176-5283}, author = {Bickerstaffe R} } @conference {40801, title = {Quality Meats From The NZ Beef And Sheep Industries - Consistent quality meat products}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {146}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Meat quality has different definitions for different people and in different countries, depending on their posi-tion in the value chain. However, the consumer who repre-sents the endpoint of the chain has clearly signaled inconsistent quality of meat as a major consideration in the declining purchases of red meat.}, issn = {1176-5283}, author = {Speck PA and Kirton AH and Clarke JN} } @conference {40870, title = {Reducing animal numbers in experiments}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {400-401}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Plasma carotenoid (PC) concentrations were measured at 2-5 month intervals in 20 Hereford x Jersey (HJ) and 20 Hereford x Friesian (HF) once bred heifers from 10-35 months-of-age. Half of the heifers were slaughtered at 31 months-of-age and the rest at 35 months-of-age. The colour of the subcutaneous and intermuscular fat was measured using a chromameter and c* values were calculated. Subcutaneous and intermuscular fats in HJ heifers were yellower (i.e. they had higher c* values) than in HF heifers. Regression equations that included breed, date of slaughter and PC concentrations at 10-12 months-of-age, accounted for 56\% of the variation in c* values for subcutaneous fat and 40\% of the variation in c* values for intermuscular fat (P<0.001).}, issn = {1176-5283}, author = {Chamove AS and Edwards HP} } @conference {40831, title = {Reduction in SCC and colostrum levels in milk after calving}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {263-265}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Somatic cell count (SCC) and immunoglobulin G1 (IgG1) content were determined in mammary secretions of 15 Friesian x Jersey cows and 5 heifers at each milking for 10 d following natural calving. Milk yields for cows on d 1 were 20.2 l/d, declined sharply on d 2 to 14.4 l/d, then increased slightly, reaching 17.9 l/d by d 10. In contrast, heifer milk yields were low on d 1 (6.6 l/d) but increased steadily to 11.9 l/d by d 10. The SCC and IgG1 levels were extremely high on d 1 (1.50 x106 cells/ml and 24.0 g/l IgG1) but declined rapidly within 48 h of calving. Average SCC and IgG1 reduced below the penalty levels by d 4 for cows, and d 5 for heifers, confirming that milk should be withheld from the bulk tank for 4 d and 5 d after calving for cows and heifers respectively. Individual cows may exceed these levels for short periods.}, issn = {1176-5283}, author = {Lacy-Hulbert SJ and Malcolm DB and Copeman PJA and Woolford MW and Franks R} } @conference {40849, title = {Relationships between adult liveweights and velvet weights in farmed Red deer}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {334-337}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Deer farmers with velvetting herds are interested in: selection of stags for superior lifetime performance; selection of stags and hinds to produce improved sons; and management of the stag herd to increase returns from velvet. Knowledge of genetic and phenotypic relationships between weights of velvet harvested at different ages and between liveweights and velvet weights will allow benefits from selection and some management practices to be quantified. This paper reports estimates of these relationships from a study involving some 2,021 stags representing 92 sire progeny groups distributed over five farms. Heritability estimates for velvet weight at successive ages from 2 to 8 year old stags ranged from 0.43 to 0.85. The average estimated genetic correlation between velvet weights in successive years was 0.97 but declined to 0.75 as the number of years between harvests increased. Phenotypic correlations were consistently lower than genetic correlations. Treating log- transformed velvet weight as a repeatable trait resulted in an estimated heritability of 0.36 with a repeatability of 0.64 and s.d. of 0.11 (log scale). Average velvet production in kg (Y) can be predicted from age in years (X) from the following equation: log10(Y) = -0.37 + 0.33*X - 0.044*X2 + 0.002*X3 Within a cohort of stags of the same age, heavier stags produced more velvet, with an average genetic correlation of 0.74 and phenotypic correlation 0.44. The genetic correlation between liveweight of hinds at 2 years of age and velvet weight at various ages averaged 0.5. Comparing different cohorts of stags of the same age, there was no relationship between average liveweights and average velvet weights. As stags aged, the average weights of velvet and liveweight increased. Describing velvet weight in kg (Y) as a non-linear function of weight in kg (X) the allometric equation was Y = 0.21*X1.4, indicating velvet weight is later maturing than liveweight. }, issn = {1176-5283}, author = {Garrick DJ and Van Den Berg GHJ} } @conference {40809, title = {Repeatabilities of blood plasma metabolites and their associations with leanness in genotypes showing a wide divergence in carcass composition}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {180-183}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Strain differences in lean : fat partitioning were typified by a marked contrast in a lean growth index giving equal but opposite emphasis to the weights of protein and fat, in line with previous publications. Strains showed characteristic differences in blood metabolites which did not necessarily reflect genetic variations within a strain and correlated responses to within-breed selection for changes in body composition. High repeatabilities of blood metabolites within a strain were found for pasture-fed lambs aged between 5 and 14 months for samples collected on the same day following overnight fasts of 20 vs 24 hours, but were lower for samples taken from fasted animals at different ages. Between-age within- strain repeatabilities (averaged across two trials) were moderate for plasma urea (0.24) creatinine (0.38) and non-esterified fatty acids (0.18), but low for beta-hydroxybutyrate (0.09). Similar moderate heritability estimates were found for urea and creatinine. Although standard errors were very high for this small dataset based on only 12 sires, estimates for carcass composition were in broad agreement with other more reliable published values. Also in line with other results, sire-progeny variations in urea and beta- hydroxybutyrate were more positively related to carcass protein than carcass fat, while the reverse was true for creatinine. Metabolically contrasting pairs of metabolites showed potentially useful predictive associations with sire- progeny variations in protein:fat partitioning.}, issn = {1176-5283}, author = {Clarke JN and Binnie DB and Dobbie JL and Jones KR and Mowat CM and Purchas RW and Uljee AE} } @conference {40769, title = {Reproductive efficiency in lactating dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {34-37}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Both genetic improvement and milk yield of dairy cows are dependent on a high reproductive performance. Under normal situations, oocyte fertilisation rates following insemination at the appropriate time are high (>90\%) and gross genetic defects in embryos are estimated to be around 10\%. This means that the biological limit of conception rate should be around 80\%. Such a performance has rarely been realised in practice, with 60\% being a normal target for lactating cows in New Zealand dairy herds. At a herd level, reproductive performance is best measured by the percentage of cows pregnant within a period after start of the breeding season and this is determined by the combination of submission rate and conception rate. Major factors that affect reproductive performance in New Zealand dairy herds include anoestrus, errors in heat detection, fertilisation failure and embryo mortality. Given adequate nutrition, herd management is undoubtedly the major determinant of reproductive efficiency. The low reproductive efficiency in dairy cows creates a bottleneck to genetic improvement and is a major factor affecting milk production efficiency. }, issn = {1176-5283}, author = {Xu ZZ and Burton LJ} } @conference {40852, title = {Reproductive senescence in aged red deer hinds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {344-346}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {This study reports on the performance of some of the original animals used to establish the Invermay deer farm. These comprised a selection of some of the original 1973 animals, 21 hinds of unknown age and 19 of the first hind calves born at Invermay in that year. Reproductive performance, expressed as the percentage of hinds weaning calves, decreased slowly from 90\% at 6 and 7 years of age, to 50\% at 17 years, then dropped markedly with only one calf being successfully reared in each season when the hinds were 19 and 20 years. Similarly, few (5/21) of the older unknown-age hinds raised calves when > 17 years old. When blood sampled twice-weekly during the breeding season (rising 21 years of age), only 6/12 of the known-age hinds had significant plasma progesterone concentrations, with only 3 animals displaying anything like normal cyclical patterns. In addition, most had elevated plasma LH concentrations. Post mortem examination revealed that all these hinds had small reproductive tracts and very few ovarian follicles at this age. Despite an ability to live beyond 20 years, these results suggest that waning reproductive performance with age may be due to ovarian failure.}, issn = {1176-5283}, author = {Fisher MW and McLeod BJ and Mockett BG and Moore GH and Drew KR} } @conference {40792, title = {The role of the vagal innervation of the gut in insulin release in lactating ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {110-113}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The vagal innervation of the pancreas and upper gastrointestinal tract has been implicated in the release of insulin in response to hyperglycaemia in several mammalian species. Therefore the role of the vagal innervation of the abomasum and upper small intestine in the release of insulin and its effect on glucose metabolism was studied in lactating ewes because of the importance of glucose for milk synthesis and secretion in ruminants. Vagal fibres innervating the abomasum, pylorus and duodenum were sectioned in 3 lactating ewes (VAG); 3 control lactating ewes underwent sham- operations (SHAM). Seven and 14 days after the surgery, all animals were given an intravenous injection of glucose (100 mg/kg BW) and jugular blood samples collected for glucose and insulin determinations. Plasma glucose concentration (mean }, issn = {1176-5283}, author = {Herath CB and Reynolds GW and MacKenzie DDS and Davis SR and Harris PM} } @conference {40860, title = {Seasonal changes in FSH and LH concentrations in ewes with gonadal hypoplasia: Evidence that steroid-independent mechanisms control seasonality in sheep?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {367-369}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Current hypotheses for the control of seasonality are based on the premise that seasonal changes in sensitivity to ovarian steroid hormones drive changes in reproductive status. Most studies have used the ovariectomised, oestrogen-treated ewe as an experimental model, but such animals may be influenced by previous entrainment or exposure to gonadal steroids. This study uses an infertile animal - the homozygous Inverdale ewe - as a unique }, issn = {1176-5283}, author = {McLeod BJ and Kyle SE and Ramsay MR} } @conference {40839, title = {Seasonal effects on fetal growth in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {297-300}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Previous studies have shown that autumn-born lambs are lighter (by 0.4 to 1.0 kg) at birth than spring-born lambs, an effect which is associated with impaired placental development in ewes mated to lamb in the autumn. As previous studies have focused on near-term fetal weights and birth weights, the objective of this study was to determine the pattern of growth throughout gestation in lambs destined to be born in the autumn or spring, and to examine associated changes in placental development. Mature N.Z. Romney ewes were randomly assigned to groups mated in December (n=23) or March (n=28) and managed on pasture in both seasons for similar live- weight profiles from mating to day 140 of gestation. Ewes were slaughtered at day 56, 84, 112 or 140 of gestation, and measures of fetal and placental weight were determined. Fetal weights (kg) of December- versus March- mated ewes were: d56 (0.040 }, issn = {1176-5283}, author = {McCoard SA and Peterson SW and Jenkinson CMC and Campbell JW and McCutcheon SN} } @conference {40772, title = {Sequence variations in genes coding for bovine Beta-lactoglobulin and alpha S1-casein}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {45-46}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The techniques involved in searching for bovine milk protein variants by the direct sequencing of genes are discussed. Examples are drawn from our studies of two major milk protein genes, b-lactoglobulin and aS1-casein. In the former case it was possible to subdivide the A and B variants even further according to point mutations found in the promoter region of the gene, while in the latter case, a New Zealand aS1 casein type A variant in Friesians was shown to arise from a point deletion in the gene which differs significantly from a mutation reported to give rise to the same type A variants in the German Red breed. The potential of this analytical approach for analysing milk protein genes is discussed.}, issn = {1176-5283}, author = {Wilkins RJ and Davey HW} } @conference {40768, title = {Sperm numbers, semen age and fertility in fresh and frozen bovine semen}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {31-34}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The consequence of a seasonal mating pattern is that a significant amount of semen from the top sires is required during this intensive mating period to satisfy the demand. To utilise semen from these top sires efficiently, liquid semen technology has been extensively used in New Zealand. This paper describes the essential physiological differences between liquid and frozen semen and their relative advantages and disadvantages. Alternative technologies such as freezing semen in bulk and later rediluted for use as liquid semen can be used to overcome the constraints of an intensive mating season. }, issn = {1176-5283}, author = {Vishwanath R and Pitt CJ and Shannon P} } @conference {40840, title = {Structural characteristics of the sheepbreeding industry and implications for genetic and reproductive technologies}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {301-303}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The structure of the sheep breeding industry needs to be understood and documented in order to assess the possible gains resulting from the implementation of genetic and reproductive technologies. This paper reports a structural description of the sheep industry, which apart from census information obtained every 5 years has received little attention since 1948. The proportion of the national flock represented by the minor and }, issn = {1176-5283}, author = {Stewart JB and Garrick DJ} } @conference {40788, title = {Supplementary feeding and gastrointestinal nematode parasitism in young grazing sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {94-98}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Young Merino wethers (n=240) were allocated to 1 of 8 treatments in a replicated field experiment. Animals grazed semi-improved pasture and received supplements for 14 or 28 weeks based on fish meal (F14, F28), sunflower meal (S14, S28) or oat grain (O14, O28). Unsupplemented parasite-free (C-) and parasitised animals (C+) were included as controls. Animal performance and parasite status were evaluated. During weeks 1-14 faecal egg counts (FEC) were below 120 eggs per gram (epg), due to low larval intake from pasture. Cumulative live-weight gain (LWG) over this period was increased as a result of supplementary feeding from 8.6 (mean C- and C+) to 11.4 kg (F14; P<0.01) or 9.9 or 9.7 kg (S14 and O14 respectively; P>0.05). From week 15 animals were dosed fortnightly with 6000 Trichostrongylus colubriformis and 2000 Haemonchus contortus larvae. Lucerne hay was fed twice weekly from week 17 onwards (2 kg/sheep/week). The FEC increased to about 5900 epg in week 28 for groups C+, F14, S14, O14 and O28 and about 3000 epg for groups F28 and S28 (P<0.05). Cumulative LWG from weeks 15-28 for groups C-, F28, S28 and O28 (0.9, 1.1, 0.6 and 1.4 kg respectively) was higher than for groups C+, F14, S14 or O14 (-1.2, -1.7, - 2.2 and -0.9 kg respectively; P<0.05). Supplementation with F, S and O during parasite infection enhanced the resilience of grazing sheep to gastrointestinal nematodes, while supplementation with F and S appear to have reduced peak FEC.}, issn = {1176-5283}, author = {Van Houtert MFJ and Barger IA and Steel JW} } @conference {40795, title = {The use of a novel approach to determine the influence of sward characteristics on the discriminatory grazing behaviour of dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {122-124}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Dairy cows were offered choices of patches of vegetation (0.8m2) on a perennial ryegrass (Lolium perenne L.) sward providing combinations of five levels of sward height (8.9 - 19.6 cm) and three levels of herbage bulk density (1.3 - 1.6 mg DM/cm3) in linear sequence. Four cows were used, each of which grazed two out of a balanced set of eight sequences, each sequence being replicated three times in a set of 27 patches in linear sequence. Animal responses were monitored in terms of grazing time and number of bites per patch. Bite number per patch increased from zero to 54 (SEM }, issn = {1176-5283}, author = {Griffiths WM and Hodgson J and Holmes CW and Arnold GC} } @conference {40841, title = {Use of bovine oocytes for the evaluation of ram semen}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {304-306}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {In vitro fertilisation (IVF) is one of a range of procedures used to evaluate the fertility of ram semen. This paper reports on the development of a heterologous IVF test, using bovine oocytes for the evaluation of frozen ram semen. An initial comparison of frozen bull (B) and ram (R) sperm with bovine oocytes using either TALP or SOF media showed a significant (P<0.001) species by media interaction on the percentage of fertilised oocytes (B-TALP 88.2}, issn = {1176-5283}, author = {Smith JF and Murray GR} } @conference {40776, title = {Utilisation of methionine by the mammary gland of the lactating goat}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {53-57}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The goat milk protein, a-lactalbumin, contains no methionine residues, hence if 35S label is supplied to the gland in the form of labelled methionine only, the appearance of 35S in a-lactalbumin gives a measure of transsulphuration of methionine to cysteine within the gland. Two lactating Saanen goats were surgically modified with catheters implanted in the mammary milk vein, femoral and external pudic mammary artery, and jugular vein to enable infusion of 35S-methionine, into either the whole body (jugular) or directly into the gland, and repetitive blood sampling. Specific radioactivity of methionine in the blood and milk proteins was determined at hourly intervals for 9 hours. Radioactivity of 35S was determined in a-lactalbumin when 35S-methionine was supplied directly to the gland via the mammary artery, but could not be detected when supplied via the jugular vein. Analysis of mammary tissue from the latter experiment did however show the appearance of 35S label in the intracellular cysteine pool which was derived from methionine. Both approaches suggested that transsulphuration within the gland, although small, may be important especially when supply of methionine to the gland is high. The fractional extraction of plasma methionine by the gland for two goats was 46.4}, issn = {1176-5283}, author = {Lee J and Treloar BP and Sinclair BR and Prosser CG and Davis SR and Harris PM} } @conference {40850, title = {Variation in fleece characteristics over the body of alpacas}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {338-341}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Variation in fleece characteristics over the body of alpacas was examined in order to determine the optimum sampling site to provide an estimate of overall fleece properties. Fibre samples were taken from the neck, shoulder, midside, mid-back and rump positions on 35 mature female alpacas. Yield was significantly (P<0.0001) lower on the neck and back and higher on the rump than on the shoulder and midside sites, 91.1, 91.0, 94.4, 94.0, 93.2 \% (se 0.3) respectively. Staple length varied significantly (P<0.001) between all sites. Fibres on the neck were considerably shorter than at other sites, with staple length at the neck only 56.7 mm compared to the other sites where length was between 80 and 100 mm. Staple length increased from rump (81.9 mm) to shoulder (99.6 mm) and from the back (86.4 mm) down the midside (92.8). Fibre diameter did not vary over the fleece (mean 33.3 }, issn = {1176-5283}, author = {Newman S-AN and Paterson DJ} } @conference {40811, title = {Variation in meat pH in steers and association with other carcass attributes: analysis of a commercial database}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {187-192}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Measurements of meat pH on 16905 steer carcasses supplied to the Richmond Asian Beef Programme in the 1993/94 and 1994/95 seasons were analysed for variability between suppliers and associations between pH and other carcass attributes. Carcass measurements were made 12 hours or later after slaughter. Factors evaluated included carcass weight, carcass grade, marbling level, age of cattle, mob size, and use of growth promotants. The frequency distribution of meat pH was highly skewed, with 92\% of carcasses falling within the range of 5.2 to 5.8, and the remainder forming a long tail above 5.8, ranging to an extreme value of 7.1. For carcasses falling in the pH range of 5.2 to 5.8, pH showed a highly significant positive association with meat colour. As pH rose above 5.8, the slope of the relationship increased and the percentage of carcasses in the darkest meat colour category rapidly approached 100\%. In the range 5.2 to 5.8, pH showed highly significant negative (P< 0.0001) associations with degree of marbling and carcass weight. After adjusting for carcass weight and marbling score, pH showed a significant positive association with age of cattle. The percentage of carcasses with a pH above 5.6 was 38\% for carcasses with a marbling score of 1. For every unit increase in marbling score (up to 5), the percentage of carcasses above a pH 5.6 specification declined by approximately 5\%. However, the proportion of carcasses with pH above 5.8 showed little association with marbling. Similarly, effects of weight and cattle age on pH were much more apparent near the mean pH (5.61) than at pH values at and above 5.8. Mob size had a small but highly significant(P<0.001) effect on the frequency distribution of pH, with smaller mobs tending to have lower pH. The effect of smaller mob size was more evident near the high pH range than in the middle of the frequency distribution. For mobs of 15 or fewer cattle, 94\% of carcasses had a pH of 5.8 or less. For mobs larger than 15, 91\% of carcasses met this specification. }, issn = {1176-5283}, author = {Smith DR and Wright DR and Muir PD} } @conference {40807, title = {Variation in sheepmeat odour and flavour}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {167-172}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Sheepmeat odour and flavour has received only spo-radic interest from flavour researchers probably because the species has only minor importance in the huge beef and pork dominated markets of North America and Japan. The characteristic odour and flavour of sheepmeat is one of the reasons its consumption is very low in these affluent markets (Young et al.,1994).}, issn = {1176-5283}, author = {Young OA and Braggins TJ} } @conference {40854, title = {Varying the form of oestradiol administration in anoestrous cows previously treated with progesterone}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {350-352}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The hypothesis tested in this field trial was that 1 mg oestradiol benzoate (ODB) could be equally effective where administered to anoestrous animals either by intramuscular injection or in a gelatin capsule per vaginum. The ODB treatment was administered to 412 cows in 8 dairy herds 24 h after the end of a 6-day priming treatment with progesterone, also administered per vaginum. By 48 h after ODB administration, 87\% of injected animals had been detected in oestrus and inseminated compared to only 44\% of herdmates receiving the gelatin capsule (P<0.01). Re-examination of those animals not detected in oestrus by 13 days after ODB treatment showed that 30\% of capsule-treated animals were still anoestrus and another 10\% had ovulated without being detected in oestrus. Comparable percentages for the injected animals were 3\% and 2\% respectively (P<0.01). The vaginal treatment was also associated with a reduced pregnancy rate to first insemination (31.7\% vs 47.7\%; P<0.05). The reduced efficacy associated with the vaginal administration of ODB to anoestrous animals most probably involved a prolonged rate of absorption which did not stimulate behavioural oestrus or an ovulatory surge of LH but did reduce fertility in those animals which were inseminated.}, issn = {1176-5283}, author = {Macmillan KL and Taufa VK and Day AM} } @conference {40803, title = {A view of the markets for beef and lamb and potential opportunities}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {151-153}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {This paper identifies some of the changes that have occurred in New Zealand}, issn = {1176-5283}, author = {Burtt A and Francis L} } @conference {40758, title = {We couldn{\textquoteright}t do it without {\textquoteright}em!}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {1-4}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The job I found most difficult during my tenure as President of this Sociery,was writing tomembers whose abstracts had not been accepted for the conference. The irony is, that a term as President carries with it the implicit responsibility of presenting a paper that does nut go through a selection process. Even more ironical is that in 1976, the incumbent President Alan Kirton noted in his annual report to the AGM, the consensus of the management committee was that in future the Presidential address should be an optional rather than an obligatory feature of the conference. }, issn = {1176-5283}, author = {Shackell GH} } @conference {40836, title = {A whole farm approach to feed planning and ration balancing using UDDER and CAMDAIRY}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {285-288}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The potential of New Zealand cows for milk production remains substantially under-utilised as a consequence of pasture-based feeding systems. One means to increase per cow production is to balance pasture diets to provide the correct quantities and ratios of nutrients to meet target levels of milksolids production, but this needs to be done in a manner which is profitable and consistent with good pasture management. The dairy farm simulation model, UDDER, was used to evaluate supplementation strategies for early and late lactation in order to increase milk yields per cow and the farm gross margin. A sample of diets from UDDER were then tested with a ration balancing model (CAMDAIRY) to identify nutrient limitations to milk production. Undegraded protein (UDP) was limiting in all diets. It was concluded that, ration balancing would be useful aid to feed management on New Zealand dairy farms, but in practice could only be sensibly used if feed and animal monitoring systems are in place to determine the type(s) and period(s) of supple}, issn = {1176-5283}, author = {Uribe JV and Parker WJ and Dake CKG and McDonald A} } @conference {40865, title = {Winter feeding of twinning beef cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {382-385}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A grazing trial was conducted in southern North Island hill country during 1994, to determine the influence of pasture allowance during winter on cow/calf performance of 40 twin- (T) and 40 single-calf (S) bearing Friesian-cross beef cows. Groups of T and S cows were grazed at low (L), medium (M) and high (H) pasture allowances for the last 4 months of gestation. Average LW in late autumn was 467 kg, and change up to 4 weeks pre- calving was LS -7.8\%, MS -2.4\%, HS +1.5\%, LT -8.1\%, MT -3.0\%, HT - 3.5\%, suggesting S cows responded to a increased pasture allowance in late gestation, but T only to M and no further to H. Blood serum bOH concentration, which was used as a measure of energy status, was not influenced by allowance treatment, but T (2.2 mmol/l) had higher concentrations than S (0.9). Twinning cows had a shorter gestation length than S cows (277 vs 284 d). Twin calves were lighter at birth (30.9 vs 44.2 kg), had lower perinatal survival (73 vs 96\%), and grew more slowly to 4 months of age than single calves (0.76 vs 1.11 kg/d). Our results suggest that }, issn = {1176-5283}, author = {Lambert MG and Devantier BP and Betteridge K and McMillan WH and Pugh PA} } @conference {40727, title = {Adapting cattle from pasture to brassica diets}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {251-254}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Strategies for adapting cattle from pasture to brassica diets were compared. Groups of 20 Friesian weaner bulls were offered three diets at a fixed daily allowance of 12\% of liveweight as drymatter on offer, for a six week period during February and March 1994. Animals continuously grazing pasture and a Wairoa brassica crop were compared to a group receiving half their allowance as pasture and half as Wairoa brassica, in separate night and day breaks. Unfasted animal liveweights were measured each week for the duration of the trial. Utilisation and botanical compositions were estimated from quadrat harvests to ground level before and after grazing. Liveweight differences among treatments at the start (overall mean 178.9 kg) and at the finish of the trial (overall mean 207.4kg) were non statistically significant (P>0.09), although growth paths differed between treatments. Both groups receiving brassica initially lost weight, the effect being most pronounced after the first week when growth rates were -0.28 kgLW/day in brassica, 0.36 kgLW/day in pasture, and -0.77 kgLW/day in the mixed diet (P<0.05). During the final week of the trial growth rates were 1.12 kgLW/day, 1.86 kgLW/day and 1.44 kgLW/day for brassica, pasture and mixed diets respectively (P<0.05). Overall average growth rates did not differ significantly (P>0.10). Large areas of crop will be required to fully realise the benefits of short term rapid growth rates. }, issn = {1176-5283}, author = {Woods PW and Couchman JN and Barlow HA} } @conference {40691, title = {Alkane technology estimates of summer and winter herbage intake of four specialty carpet wool breeds, Romneys and Merinos}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {130-132}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Groups of between 12 and 39 mixed age alpaca females with young at foot, and similar numbers of non-lactating Wiltshire Horn sheep, were grazed in three sets of paired plots of mixed perennial ryegrass/white clover/Yorkshire fog/cocksfoot pastures. Each pair of plots was grazed twice over a period of four months (January-June) in order to compare patterns of grazing behaviour and diet selection. All pastures contained substantial proportions of dead material. Grazing behaviour was recorded manually over 24 hours in each period, and diet selection assessed from marked grass tillers and clover nodes set out on long transects in each plot. Alpacas and sheep spent similar time grazing (8.7 vs 8.5 }, issn = {1176-5283}, author = {Champion SC and Robards GE and Lindsay AR and Friend MA} } @conference {40717, title = {Antibody class-specific immune responses in ovine milk measured by ELISA}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {218-220}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Hodgkinson AJ and McQuoid MR and Hodgkinson SC} } @conference {40670, title = {Apple pomace as a supplement to pasture for dairy cows in late lactation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {67-69}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Eye muscle dimensions of meat and fat together with live or carcass weight are important selection criteria for the improvement of carcass traits in sheep. The use of B-mode ultrasound may offer scope for more efficient progeny testing procedures. Two trials examined the use of ultrasound for estimating eye muscle width (A) and depth (B) between the twelfth and thirteenth ribs on live animals, and their carcasses immediately following slaughter and up to nine hours later. These estimates were then compared with ruler measurements on the eye muscle cut surfaces. Correlations between the various estimates of B were high (r = 0.80 to 0.96). While the correlation between the live scan of A and its ruler measurement was 0.75, the correlations between carcass scans and ruler measurements were 0.40 to 0.61. This was due to difficulty in maintaining acoustic coupling over the length of the probe, which was flat relative to the curved carcass surface. A new curved offset offers excellent prospects for overcoming this problem. }, issn = {1176-5283}, author = {Edwards NJ and Parker WJ} } @conference {40685, title = {Assessment of lamb meat quality in Sydney and Melbourne}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {114-116}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Over two years at Whatawhata Research Centre mixed age Hereford x Friesian beef cows pregnant with either one or two calves were compared in a feed intake study. Pasture dry matter (DM) intake by the cows was estimated using slow- release, chromic oxide, rumen capsultes. Twin pregnant/suckled cows ate similar amounts per day as }, issn = {1176-5283}, author = {Hopkins DL and Ferrier GR and Channon HA and MacDonald BA} } @conference {40667, title = {The behaviour of calves tail docked with a rubber ring used with or without local anaesthesia}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {58-60}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The concentrations of cholesterol and triglyceride in blood plasma were compared in two genetically distinct herds of Angus cattle. Any concentration differences between the herds should indicate a realised genetic response to selection for yearling weight. Seventy-four yearling Angus cattle from the Waikite weight selection and control herds were blood sampled after a 24-h fast in July, September and November 1993 (heifers twice, bulls three times; n=178 samples). Plasma cholesterol concentrations averaged 2.73 and 2.91 (s.e.d. 0.08) mmol/l in the two herds, respectively (P<0.05), and triglyceride concentrations averaged 0.296 and 0.316 (s.e.d. 0.015) mmol/l, respectively. There was a 30kg (14\%) difference in yearling live weight between the two herds (P.001). Both metabolites showed moderate between-animal repeatabilities, 0.52+0.11 and 0.37+0.16 respectively, and there was a positive phenotypic correlation of 0.40 between cholesterol and triglyceride concentrations within herds. These results show that a 14\% higher weight-for-age as a result of selection was associated with a 6\% lower plasma cholesterol concentration. This was consistent with our previously observed cholesterol difference in cooked beef from the same herds. }, issn = {1176-5283}, author = {Petrie NJ and Stafford KJ and Mellor DJ and Bruce RA and Ward RN} } @conference {40718, title = {Bio-impedance monitoring of genital tissues of cows as an aid in cattle reproductive management - a review}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {221-223}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Lehrer AR and Lewis GS and McMillan WH and Aizinbud E} } @conference {40728, title = {Brief Communication - The cost of producing feedlot beef in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {255-256}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {In recent years there has been considerable interest in feedlotting as a means of producing beef carcasses with more desirable characteristics (eg. improved fat colour, marbling). This paper outlines the cost of feeding heavyweight cattle on a feedlot ration and the likely premiums required to meet this additional cost. In three experiments Angus steer were fed 70\% grain diets ad libitum for at least 14 weeks. In experiments 1, 2 and 3, respectively, steers grew from 621 to 761 kg, 574 to 674 kg and 563 to 657 kg, over 70, 68 and 71 day period, respectively. Feed intakes averaged 15.2 kg of dry matter per day and were 2.2\% of bodyweight. Average liveweight gain was 1.60 kg/day and average feed conversion efficiency was 9.5 kg feed per 1 kg of liveweight gain. Based on typical New Zealand feed costs, the average daily feed cost was $3.44 per head and the premium required to recoup the feed cost alone would need to be $1.18 per kg of total carcass weight. Approximately $1.48 per kg would be required to cover all costs. }, issn = {1176-5283}, author = {Muir PD and Smith NB and Wallace GJ} } @conference {40688, title = {The Calpain System - genotype, nutrition and their interactions}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {123}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Three groups of pregnant (3rd trimester) cows grazing low Se pastures were given daily Se intakes of 0.44, 0.94 and 1.44mg respectively as pasture plus a drench. A significant relationship between blood Se concentration (nmol/l) [y] and daily Se intakes (mg/day) [x] was described by the equation Y=147(44.0+(359(42.1)X***. Given that a mean blood Se concentration of 250 nmol/l reflects an adequate Se status, that is there is no production response to Se supplementation, then the daily Se intake of pregnant cows was determined to be 0.29mg or pasture should contain 0.037mg Se/kg DM to prevent Se deficiency. }, issn = {1176-5283}, author = {Speck PA and Singh KK and Thomson BC and Dobbie PM and Mercer GK and Bass JJ and Simmons N and Binnie B and Clarke N} } @conference {40671, title = {Calving patterns in dairy heifers following single {\textquoteright}set-time{\textquoteright} inseminations and re-synchrony preceding second inseminations}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {70-71}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Retail audit studies were undertaken in both Sydney and Melbourne to establish benchmarks for quality at the retail level. Midloins were obtained from ticketed carcasses at 14 retail outlets in Sydney, on 3 occasions (2x3) during the same week in March 1994. In Melbourne, midloin samples were obtained from non-ticketed carcasses in 38 and 40 retail outlets in June 1993 and January 1994 respectively. Using an L* value of 32 and a pH value of 5.8 as criteria of acceptability it was found that similar numbers of unacceptable samples occurred in both cities. Using a Warner Bratzler (WB) shear force of 5 kg as an indicator of unacceptable toughness, 15\% of samples from Sydney were unacceptable compared to 5\% in Melbourne. Carcass age significantly (P<0.001) influenced the WB values for Sydney samples. When WB values were adjusted to 1 or 3 day old equivalents 27\% and 6\% exceeded 5kg respectively. The results indicate that management options (such as aging), and objective measurement of carcass and meat quality can be applied to increase knowledge and improve the overall quality of lamb and its reputation with consumers. }, issn = {1176-5283}, author = {Cliff SC and Morris GR and Hook IS and Macmillan KL} } @conference {40672, title = {Characteristics of seasonal dairy farms achieving high per cow production in the lower North Island of New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {72-75}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The accuracy of multi-frequency bioimpedance analysis (MFBIA) as a predictor of carcass composition in lambs was assessed in a small study. Impedance and its}, issn = {1176-5283}, author = {Crawford HK and Gray DI and Parker WJ and Edwards N} } @conference {40741, title = {Commercial performance of sheep carrying the Inverdale gene (FecX)}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {294-295}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The progeny testing of 12 Romney rams from a family in the Woodlands high prolificacy flock provided an opportunity to improve the 88\% lambing percentage from the 3200 ewe flock on a Southland farm. Over four years, ewes with the Inverdale gene averaged an extra 35 lambs weaned per 100 ewes jointed. The little size averaged 2.38 for Inverdale ewes, with 11\% having singles, 45\% twins, 39\% triplets and 5\% quadruplets. More than 80\% of Inverdale ewes reared>lamb, and the second generation Inverdale ewes reared larger and more lively lambs. Weaning weights at 12 weeks of age averaged 22kg, which, due to the large number of lambs reared as multiples, was lighter than the commercial flock. However, by eight months of age Inverdale and commercial hogget weights were similar. High feeding levels during lactation have been critical to the success of the Inverdale flock. }, issn = {1176-5283}, author = {Gray AJ and Davis GH} } @conference {40726, title = {Comparison of cervical, transcervical and laparoscopic insemination of ewes with chilled stored and frozen ram semen}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {248-250}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A technique for transcervical artificial insemination (TAI) of the ewe has been reported as an alternative to laparoscopic intrauterine insemination (LAI). This study evaluated the techniques under New Zealand conditions. Romney ewes (365) were treated in February for 14 days with CIDR}, issn = {1176-5283}, author = {Smith JF and Parr J and Beaumont S and Oliver JE and Upreti GC} } @conference {40660, title = {A comparison of protocols for the photoperiodic induction of synchronised wool follicle growth cycles}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {35-38}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {This study endeavoured to characterise the effects of breed and calving liveweight (CW) on postpartum (pp) ovarian activity in 16 Friesian (F) and 16 Jersey (J) heifers. Half of the animals within each breed were differentially fed (High vs Low: H vs L) during the 8 weeks before calving to achieve CWs (24 h pp) of 404 (FH), 354 (FL), 334 (JH) and 279 (JL) kg. They were fully fed as one group after calving. Ovarian ultrasonography showed that the FL group had the longest postpartum anovulatory interval (PPAI) of 77 days compared to 47 days among other groups. The second dominant follicle pp emerged 6 days later in FL heifers. Breed, but not CW, affected follicle patterns in the first normal oestrous cycle. Underfeeding of Friesian heifers during late pregnancy extended the PPAI whereas Jerseys were not affected to the same extent. }, issn = {1176-5283}, author = {Craven AJ and Parry AL and Ashby MG and Pearson AJ} } @conference {40698, title = {Compensatory growth in cattle - revisited}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {157-160}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Perendale flocks bred for divergence in lambs}, issn = {1176-5283}, author = {Nicol AM and Kitessa SM} } @conference {40757, title = {Contract Summary}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {332}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Rohloff M} } @conference {40696, title = {Cortisol response to ACTH in lambs selected for or against fatness: Effects of maturity and fasting}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {150-153}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Lambs grazing the tannin containing pasture species Lotus corniculatus (cv Goldie) were compared with lambs grazing a high endophyte ryegrass (cv Nui) in order to assess the effectiveness of lotus at reducing dags and flystrike. Two trials of the same design were run consecutively, between January and April 1994. Each of 4 paddocks, 2 of lotus and 2 of ryegrass, were set stocked for 32 and 42 days (respectively for trials 1 and 2) with 62 lambs. Half of the lambs in each paddock were drenched fortnightly with a combination anthelmintic. Lambs were examined for flystrike three times each week and samples were collected for fly identification before strikes were treated with insecticide. Lambs which grazed lotus suffered less flystrike than those grazed on ryegrass in both trials (32\% of 51\%; P<0.01 and 1.5\% cf 7.4\%; P<0.05 for trials 1 and 2 respectively). Drenching reduced flystrike in trial 1 (from 57\% to 26\%; P<0.01), but not in trial 2 (4.8\% cf 4.1\%; NS). Flystrike was strongly correlated with dagginess (R2=97\%). Mean dry weight of dags was reduced by grazing lotus rather than ryegrass (79g cf 108g; P<0.01 in trial 1 and 9.7g cf 14.3g; NS in trial 2) and by drenching (68g cf 118g; P<0.01 in trial 1 and 8.8g cf 15.2g; NS in trial 2). Lambs grazing lotus had significantly (P<0.01) higher faecal dry matter content than those grazing ryegrass. We conclude that lotus has considerable potential for a future role in the integrated management of flystrike and dags. }, issn = {1176-5283}, author = {Veenvliet BA and Littlejohn RP and Stuart SK and Suttie JM} } @conference {40710, title = {Dagginess and flystrike in lambs grazed on Lotus corniculatus or ryegrass}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {196-198}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Leathwick DM and Atkinson DS} } @conference {40700, title = {Development of a management system to intensify and increase beef production in a range suckler herd in Israel - {\textquoteright}the Amaziah project{\textquoteright}}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {165-168}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Repeated sheep treatment with the anthelmintic drug benzimidazole (BZ) resulted in selection of genetically benzimidazole-resistant (BZ-R) nematodes, which code for a specific allele of isotype 1Beta-tubulin. The presence of this allele was tested in the Waikato ovine nematode, using an allele specific PCR. Two isotype allele specific oligomers for O. circumcincta (O.c.) Beta-tubulin gene were designed. The last base at the 3}, issn = {1176-5283}, author = {Lehrer AR and Kahn HE and Kreitzer J and Gacitua H and Mizrachi Y and Kali J} } @conference {40664, title = {Differences in propensity of wool to develop yellow discolouration in flocks of Perendale sheep selected for and against}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {46-49}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {CONFIRM is a recently developed test kit for verifying pregnancy in dairy cows on the basis of the concentration of oestrone sulphate (OS) measured in a milk sample taken at least 120 days after mating/insemination. In this study, the performance of CONFIRM was evaluated using milk samples from non-pregnant cows returning a }, issn = {1176-5283}, author = {Reid TC and Botica KJ and Sumner RMW} } @conference {40739, title = {Discovery of the Inverdale gene (FecX)}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {289-290}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Selection for ovulation rate in a screened prolific flock identified a prolific family of Romneys in 1984 that descended from one ewe, and progeny tests for her male descendants carried out from 1985 to 1990 indicated the presence of a major gene (Inverdale) on the X- chromosome. One copy of the gene increases ovulation rate by about 1.0 and litter size by about 0.6. However, research in 1991 found that ewes with two copies of the gene have small non-functional {\textquoteright}streak{\textquoteright} ovaries and are infertile. Many of these infertile ewes develop tumour-like structures on their ovaries and these are currently the subject of intensive research. In 1993 a prolific Romney flock in Tokoroa, with no known connection with A281, was also found to have the Inverdale gene. The place of the Inverdale gene in industry will be to increase prolificacy in ewe flocks mated to terminal sires, and a research programme has been established to identify a genetic market for ram breeders. }, issn = {1176-5283}, author = {Davis GH and McEwan JC and Fennessy PF and Dodds KG} } @conference {40675, title = {Early lactation response of dairy cows to pasture under two different nitrogen fertiliser regimes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {82-84}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Near-infrared (1100-2500 nm) reflectance spectra were measured on 128 beef ribeye samples using a scanning monochromometer and calibrated against standard laboratory analysis to develop a rapid method for measuring intramuscular fat of beef. A pilot run was conducted on 38 frozen ribeye samples, ranging in fat content from 94 to 325g/kg dry weight, to evaluate sample preparation methods (frozen slices, thawed slices, coarse mince. After scanning of subsamples, fat content of the sample was then measured using Soxhlet extraction. Standard error of calibration (SEC) was 9g/kg dry weight for spectra collected from minced samples compared to 25g/kg for frozen slices and 15g/kg for thawed slices. A second set of 90 frozen ribeye samples (fat content range 56-305 g/kg dry weight) was used to test and improve this calibration, using 3 subsamples of minced beef per sample. The ability of the initial calibration equation to predict fat content of these samples was poor. A more robust calibration was then attempted by pooling the data from the two sets. The SEC of this extended set was 16 g/kg dry weight (10\% of the sample set mean) and the multiple R2 of calibration was 0.92. The standard error of prediction for new samples was estimated from internal cross-validation runs as 19 g/kg. Prediction of fat content of an independent validation set of 24 samples had a standard error of 20 g/kg dry weight. Analysis of the calibration results suggested that a major source of error in the calibration was hererogeneity between subsamples, with the standard deviation of prediction of different subsamples from the same ribeye being larger than the standard error of cross validation. These results indicate that Near-Infrared reflectance spectroscopy may provide a rapid objective method for estimating intramuscular fat of beef. }, issn = {1176-5283}, author = {Mackle TR and Parr CR and Bryant AM} } @conference {40729, title = {Effect of allowance and the rate of adaptation of weaned calves to two brassica types}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {257-260}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Groups of 10 Friesian bull calves averaging 142 kg were offered Winfred forage brassica (62\% leaf) at allowances of 3, 6, 9, 12 or 15\% of bodyweight (BW) for 6 weeks. Similarly, groups of 8 Friesian bull calves averaging 150 kg were offered Wairoa forage brassica (67\% leaf) at allowances of 3, 5, 7, 9 and 12 \% of bodyweight. Calves were weighted weekly and offered fresh allowances each week. The two experiments were conducted between January and March of the same year but were not run concurrently. There was a significant effect (P<0.01) of allowance on liveweight gain for calves offered Winfred, with calves on the lowest allowance (3\% of BW) growing at 0.90 kg/day, compared to 1.20 kg/day for calves grazing the other four allowances. Calves grazing the low allowance (3\% of BW) utilised 77\% of the total crop, but only 43\% of the stem. On the other hand, calves grazing the low allowance of Wairoa utilised 90\% of the total crop and 72\% of the stem without suffering a liveweight penalty. There was no effect of allowance of Wairoa on calf growth rate and overall, calves on Wairoa grew at an average of 1.03 kg/day. Choice of a leafy type of brassica maybe important if the objective is a high degree of utilisation coupled with good animal performance. Alternatively, on }, issn = {1176-5283}, author = {Muir PD and Wallace GJ and Slay MWA} } @conference {40715, title = {The effect of anthelmintic treatment of ewes during pregnancy}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {211-213}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Familton AS and McAnulty RW and Thompson KF and Sedcole JR} } @conference {40694, title = {Effect of continuous stocking of breeding ewes at different sward surface heights during the late summer-autumn on herbage intake and productivity}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {141-144}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {This study aimed to raise GnRH antibodies in young bulls (immunocastration) and determine the subsequent effect on behaviour, sexual development, carcass characteristics and meat quality. Thirty Friesian bull calves were assigned to one of three groups balanced by liveweight (control bulls, immunocastrates and steers). At nine months of age (Day 0) immunocastrates were vaccinated against GnRH (Vaxstrate) and boosted one month later (Day 31). Following immunisation there was a rise in GnRH antibody titre and a decrease in testosterone. Control animals gained significantly more weight than immunocastrates and steers in the first 157 days. Overall there was no difference in weight gain between controls and immunocastrates. Mean scrotal diameter of immunocastrates decreased from Day 31 to Day 110 and then rose to reach a diameter similar to those of the control bulls by Day 322. Leg wear scores were lower for treated animals compared to controls until Day 230 of the trial, although these differences were not significant. Immunocastrates had a significantly higher mean ultimate pH than both control bulls and steers. Bulls were significantly leaner than immunocastrates, and both groups were leaner than steers. }, issn = {1176-5283}, author = {Panggabean AU and Morris ST and Parker WJ and McCutcheon SN} } @conference {40713, title = {Effect of control of internal parasitism on productivity of Merino breeding ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {205-208}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Sumner RMW and Watson TG and Hosking BC} } @conference {40725, title = {Effect of diluent type and storage time on the pregnancy rate of ewes inseminated laparoscopically with chilled ram semen}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {245-247}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Five trials involving 879 ewes were conducted in November, December 1993, February, March and April 1994. Ewes were synchronised with CIDR}, issn = {1176-5283}, author = {Smith JF and Parr J and Murray G and Oliver JE and Beaumont S and Upreti GC} } @conference {40708, title = {The effect of immunological castration on behaviour and growth of young bulls}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {190-192}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Jago JG and Lasenby RR and Trigg TE and Claxton PD and Matthews LR and Bass JJ} } @conference {40674, title = {Effect of level of nutrition on age of puberty and reproductive performance of Friesian heifers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {79-81}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Muscle proteolysis is controlled by a number of enzyme systems. The reported effects of the calcium dependent proteinases (or calpains) on myofibrillar structure have led to the speculation that this enzyme system may have an important role in regulating muscle growth and the post mortem ageing process. Although at present there is no clear economic incentive, meat quality has to be taken into account since the white meats of poultry and pork are out competing the traditional red meats of lamb and beef. Meat quality attributes may largely depend on slaughtering and post mortem ageing regimes, however, variability also originates from the biological characteristics of muscles which are undoubtedly environmentally and genetically controlled. The aim of the present experiment is to examine the effect of genotype, nutrition and their interactions on the calpain system. Progeny from 3 sire breeds (Texel, Fat Southdowns and Lean Southdowns) were weaned in December and placed onto one of two growth paths until May (high (H) or low (L) rate of gain), from May until July these groups were further divided into groups HH, HL, LL and LH. Animals were slaughtered at the Ruakura commercial slaughter facility, samples for calpain analysis were taken from the distal portion of the longissimus dorsi of the animal within 20 minutes of slaughter. The assays were performed as outlined by Dobbie et al., (1995). Calpain-I differed significantly (p<0.05) between genotype (Texel 0.57 SDFat 0.50 SD Lean 0.41 U/g (SED 0.060). Calpastatin was significantly (P<0.05) affected by plane of nutrition immediately after weaning. (H:2.61 L:2.35 U/g SED 0.126). The results taken together suggest that complex physiological interactions exist between genotype and nutrition with respect to the calpain system. }, issn = {1176-5283}, author = {Penno JW and Macmillan KL and Bryant AM} } @conference {40731, title = {Effect of Monensin capsules on blood metabolites near calving in twin- pregnant and single-pregnant beef cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {265-267}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The aim of this study was to test the hypothesis that Rumensin capsules administered during late pregnancy would have equally beneficial effects in single- and twin-pregnant beef cows, on circulating levels of beta- hydroxy butyrate (BOH), magnesium (Mg) and glucose. Forty cows, half of which were twin pregnant, were treated with either a single Rumensin capsule from a mean of 66 d prior to calving, or remained as untreated controls. Plasma samples were taken on d66, 38, 23, 13 and 5 prior to calving. Rumensin lowered BOH concentration by the second sampling time (0.53 vs. 0.765 mmol/l, P<0.01) and maintained this concentration until calving. Rumensin was without effect on Mg or glucose concentrations. The effects of Rumensin were additive to those of pregnancy status (twin vs. single) for all three metabolites thus confirming our hypothesis. Rumensin may therefore be useful in the late pregnancy management of twin pregnant cows. }, issn = {1176-5283}, author = {McMillan WH and Oakley AP and Hewitt W} } @conference {40669, title = {Effect of nitrogen fertiliser and summer rotation length on milk production in a dry Waikato summer.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {64-66}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Muscling is considered important by the New Zealand meat industry. As Texel cross lambs contain more muscle than most other sheep genotypes, a muscling trial was undertaken using Texel and Oxford cross and High Romney mixed sex lambs. Eighteen lambs were slaughtered from each breed. The muscle, bone, subcutaneous and intermuscular fat were separated from the leg and shoulder of the 54 right sides. The leg comprised on average 64.4\% lean in the High Romneys, 66.2\% in the Oxford cross lambs and 67.4\% in the Texel cross lambs (p<0.05). The corresponding figure for shoulder lean 58.8\% (Romney), 59.9\% (Oxford) and 62.1 (Texel) (p<0.05). The eye muscle area (cm2) for these lambs was 9.8 (Romney), 11.0 (Oxford) and 11.7 (Texel). The muscle:bone ratio (weights) for 4 leg muscles to the femur were 7.0 for the Romneys, 7.6 for the Oxford and 8.3 for the Texel cross lambs (p<0.10). Only 2 non Texel lambs were classed E under the European classification system. }, issn = {1176-5283}, author = {Penno JW and Bryant AM and Carter WA and MacDonald KA} } @conference {40652, title = {Effect of once daily milking (ODM) on enzyme activities in the bovine mammary gland}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {12-13}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Maintenance diets containing two levels of energy (9.6 v. 11.5 MJME per kg DM) and two levels of protein (10.7 v.21.7 g nitrogen per kg DM) were fed to four groups, each of ten Romney (five low and five high staple tenacity) and four Drysdale yearling rams, for six weeks from mid March. Protein supplementation increased protein intake by 114\% (P<0.001). It increased clean wool growth in the treatment period (6.2 v. 10.2 g.um- 2.d-1, P<0.001), more so in Drysdales than Romneys (89 v. 46\%; P<0.001). It also increased mean fibre diameter (38.1 v. 34.3 um, P<0.001) without changing the proportion of fibre that was medullated. Responses to the nutrient supplements were similar in low and high staple tenacity Romney rams. It is concluded that during the photoperiod-induced decline in wool growth in autumn, sheep on a maintenance diet responded to the increase in dietary protein with an increase in the volume of fibre and volume of keratin produced with no net change in the proportion of fibre medullated. }, issn = {1176-5283}, author = {Farr VC and Stelwagen K and Kerr MA and Davis SR and Eichler SJ} } @conference {40650, title = {Effect of once-daily milking and bovine somatropin administration in Friesian cows on milk protease activity}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {7-8}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Samples of wool from Perendale hoggets born at Whatawhata Research Centre in 1989 from ewes selected for and against loose wool bulk were tested for propensity to yellow. After storage in a laboratory for two years, wool from the high bulk line was significantly more yellow than wool from low bulk line. When the greasy wool was incubated at 40 degrees and 100\% relative humidity, differences in all three tristimulus values between high and low bulk wool were significant. Tristimulus Y and Z decreased and Y minus Z increased when clean wool samples were subjected to more extreme challenges similar to those which may occur during processing. These changes did not affect the differences in colour between the selection lines. These results suggest that management changes may be required to restrict yellowing of high bulk wool during growth and storage. Simultaneous selection for reduced propensity to yellow and increased bulk may reduce the genetic progress attainable in either characteristic. }, issn = {1176-5283}, author = {Stelwagen K and Whyte JH and Zavizon B and Prosser CG and Davis SR and Farr VC and Politis I} } @conference {40706, title = {The effect of peramine ingestion in pen-fed lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {186}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Little research has been done on within breed differences in seasonality of reproduction in rams. We took 16 Dorset x Romney rams (8 BV+ and 8 BV-, selected on the basis of their breeding value for date of lambing derived for the lambing performance of their female relatives). These rams were housed indoors under natural light conditions and fed a ration of pellets and hay. Semen samples, testis diameter and body weight measurements were taken weekly. Blood samples were taken monthly (every 20mins for 26hrs, and then every 10mins for a further 4hrs following a 1 ml IV injection of 0.001 mg GnRH). Samples were assayed for oLH and oFSH. The trial ran from September 1993 to August 1994. More BV- (early lambing group) rams (70\% vs 25\%) produced ejaculates in the first 3 months of the trial. The BV- rams had significantly (P<0.001) lower ejaculate volumes than the BV+ rams with both showing significant (P<0.001) seasonal changes. There were significant (P<0.01) seasonal effects on semen concentration with a January maximum of 6300 x 10 6 sperm/ml and a minimum in July of 3350 x 10 6 sperm/ml. There was a seasonal effect on testis diameter (55mm in Dec-Feb and 38mm in July). There was a significant (P<0.05) seasonal shift in live weight between Feb-Apr (70kg) and July 58kg). There was significant (P<0.01) seasonal effect on basal LH levels and LH pulse frequency, but there were no detectable BV effects. The BV- rams had greater pulse amplitude and longer durations of peaks than did the BV+ animals. LH response to GnRH was significantly different only in Nov (BV- rams showed greater area under the curve 162}, issn = {1176-5283}, author = {Pownall DB and Familton AS and Field RJ and Fletcher LR and Lane GA} } @conference {40679, title = {The effect of season and Beta-lactoglobulin phenotype on milk composition}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {94-96}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {128 carpet wool ewes, Romneys and Merinos of between 12 and 30 months of age, were set stocked for 13 months on a property at Oberon NSW. Live weights (LW) for Carpetmasters, Drysdales, Romneys and Tukidales were similar with Elliottdales being slightly lighter and the Merinos lighter again, giving rise to significant breed effects for maximum live weight (LW MAX) and minimum live weight (LW MIN). Wool growth (WG) of each breed was similar during winter, with significant differences between breeds appearing during summer. Breed had a significant effect on amplitude of live weight (LW AMP) and wool growth (WG AMP). There is a strong positive correlation between LW MAX and LW MIN and negative correlations between LW MIN and LW AMP, and minimum wool growth (WG MIN) and WG AMP. Regression analysis for predicting WG from LW and change in LW was unsuccessful with low R2(\%) values especially during winter. It appears that nutritional influence on WG during winter may be minimal. }, issn = {1176-5283}, author = {Hill JP and Paterson GR and Lowe R and Wakelin M} } @conference {40697, title = {Effect of selection for early lambing on the expression of hogget oestrus activity}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {154-156}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The effect of grazing parasitised ewe lambs on herbages with and without condensed tannins (CT}, issn = {1176-5283}, author = {Smith JF and Parr J and Murray G and Harris C and Duganzich DM} } @conference {40720, title = {Effect of selection for early lambing performance on the seasonal patterns of gonadotrophin levels; response to GnRH and semen characteristics}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {228-231}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Brewer JC and Briggs RM and Parr J and Wilkins RJ and Smith JF} } @conference {40711, title = {The effect of six herbages on liveweight gain, wool growth and faecal egg count of parasitised ewe lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {199-201}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Robertson HA and Niezen JH and Waghorn GC and Charleston WAG and Jinlong M} } @conference {40722, title = {The effect of stocking rate and breed on the period of postpartum anoestrum in grazing dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {236-238}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The effects of stocking rate (low, L; and high, H), breed (Jersey, J; and Friesian, F) and age (2, 3, >3 years old) on the intervals from calving to first ovulation and to first oestrus were assessed in pasture grazed dairy cattle using a 2 x 2 design. Cows in the FH herd had longer intervals from calving to first postpartum ovulation (C-ovn1; 49.2 vs 24.7, 31.1 and 29.4 days) and C-hl (47.1 vs 32.5 days) intervals than older cows, with 3 year old cows intermediate. The high stocking rate herds had reduced CS, liveweight and milk production compared to the low stocking rate herds. Condition score and milksolids production were inversely related to the C-ovnl and/or C-hl intervals. Increased stocking rates were associated with longer periods of postpartum anoestrum. }, issn = {1176-5283}, author = {McDougall S and Burke CR and Williamson NB and Macmillan KL} } @conference {40677, title = {The effect on incidence of bloat of changing pasture herbage mass and species}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {88-90}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The study involved 128 animals (19 Carpetmasters, 20 Drysdales, 19 Elliottdales, 20 Merinos, 23 Romneys and 27 Tukidales) maintained on improved pastures at Oberon, on the central tablelands of NSW. For the intake measurements, animals were stratified on liveweight into five groups within breed, and one animal selected from each group at random for dozing with controlled-release alkane capsules. The intake of Romneys (1.30 kgOM/day), Merinos (1.20) and Tukidales (1.18) was significantly (P<0.05) higher than that of Carpetmasters (0.98), Drysdales (0.78) and Elliottdales (0.80). There was no significant interaction between breed and season, with all breeds having a lower (P<0.01) intake in July (0.63) kgOM/d) than February (1.43 kgOM/d). When the intakes were expressed in terms of metabolic liveweight, there was again a highly significant difference between the intake in February and July (0.078 and 0.040 kgOM/g/LW0.75, respectively). On a metabolic liveweight basis breed differences also still existed, with Merinos (0.082) having higher (P<0.05) intakes than the other breeds. }, issn = {1176-5283}, author = {Carruthers VR} } @conference {40673, title = {Effects of breed and calving liveweight on postpartum ovarian activity in pasture-fed dairy heifers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {76-78}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {There is little information available on the muscle biology of deer and how this affects meat quality. The reported effects of the calcium dependent protease system (calpains and their inhibitor calpastatin) on protein turnover in vivo and myofibrillar structure posts mortem suggest it may have a pivotal role in regulating muscle growth and meat tenderisation. This study examines inter-muscle variation in the calpain system under two physiological conditions in red deer and its relation to meat tenderness. Nine muscle samples from 3 stags in rut (IR) and 3 out of rut (OR), were processed for calpain and calpastatin analysis within 20 minutes of slaughter. Tenderness of aged muscles was determined by measurement of ultimate shear force. The majority of the inter-muscle differences in the calpain system were associated with calpastatin activity. A positive relationship between muscle calpastatin levels and meat ultimate shear force was found. }, issn = {1176-5283}, author = {Burke CR and McDougall S and Macmillan KL} } @conference {40682, title = {Effects of genotype and nutrition on sheep carcass fat and eye muscle development between weaning and 14 months of age}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {104-107}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Although several studies have implicated cortisol in the control of body composition in sheep, the precise mechanisms are unclear. Cortisol basal concentration and response to an ACTH challenge was studied in Coopworth wethers selected for (Fat) or against (Lean) fatness in both the fed and 48 hour fasted states at two stages (15 and 33 weeks). The aim was to investigate whether fasting, age or genotype would influence cortisol secretory parameters. Mean basal cortisol concentration was higher for fasted than fed lambs (13.6 versus 8.9 ng/ml, p<0.001), but did not differ significantly with genotype or overall stage of development. Maximal cortisol response to ACTH was greater for the fat than the lean genotype, at both 15 weeks (86.3 versus 65.3 ng/ml, p<0.01) and 33 weeks (108.2 versus 91.1 ng/ml, p<0.01) of age. Maximal cortisol response was also significantly greater with fasting and increasing age, but the effect of fasting on cortisol increase was greater at 15 than 33 weeks of age. Clearance of cortisol was significantly slower after fasting, but unaffected (p>0.05) by genotype and development. Basal cortisol concentrations was not associated with differences in body composition between the fat and lean genotypes. However the larger maximal response in the fat genotype may indicate that the adrenal gland plays a role in determining body composition. }, issn = {1176-5283}, author = {Binnie DB and Clarke JN and Clayton JB and Mowat CM and Purchas RW} } @conference {40655, title = {Effects of induced parturition on mammary function}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {21-22}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Four 6.4 ha farmlets each stocked with 24 high genetic merit Friesian cows were used to determine the effect of nitrogen fertiliser (N), and a long summer grazing rotation on pasture and milk production in summer. Treatments were 0 )-N) or 50 kg N/ha (+N) in December, January and March and a 16 day (16) or 40 day (40) rotation. Treatments started 15 December, following a two week uniformity period, and ran until 29 April. On the 16 and 40 day rotations N increased net herbage accumulation by 0.8 t DM/ha, and milksolids (MS) production by 92 and 38 kg/ha respectively. Across both nitrogen treatments, the 40 day rotation increased net herbage accumulation by 1.7 t DM/ha. The MS production was 39kg/ha greater on the -N40 than the -N16 treatment whereas that of the +N16 and +N40 did not differ significantly. The N and long rotation treatments also resulted in higher average herbage mass and cow condition at the end of the experimental period. It is concluded that N in early summer and a long summer rotation are useful management practices to reduce the effects of summer dry periods. }, issn = {1176-5283}, author = {McFadden TB and Verkerk GA and Clark BA and Hovey RC and Macmillan KL} } @conference {40740, title = {Elucidation of the genetic nature of the Inverdale gene (FecX): Segregation with a twist}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {291-293}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A major gene, affecting a quantitative trait in farmed livestock, is usually detected by observing segregation of the gene within families such as half-sib sire families. In the case of the Inverdale, a maternal family was observed to contain some highly prolific ewes. Progeny testing of four rams from this family revealed two rams with prolific progeny, but segregation amongst these progeny was not apparent. The data appeared to be consistent with the hypothesis of an X-linked major gene, but were not conclusive. A further progeny test involving six sons and five maternal grandsons of a putative Inverdale ram was undertaken. Three of the maternal grandsons but no sons had prolific daughters, confirming the X-linked hypothesis. Further major gene searches should consider X-linked as well as other modes of inheritance. The mode of inheritance, and effect of one and two copies of the Inverdale gene, have important consequences for its use in research and production. }, issn = {1176-5283}, author = {Dodds KG and Davis GH and McEwan JC and Fennessy PF} } @conference {40680, title = {Endocrine manipulation of the pregnant animal and growth of her offspring: a review}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {97-100}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The Stockpol model was designed for decision support on New Zealand sheep and beef cattle farms. It indicates the biological feasibility of a livestockj system and provides the opportunity for users to test alternative livestock policies. An evaluation of the Stockpol model was made using 44 data sets from farmlet trials at Gore, Ballantrae and Whatawhata Research Centres and data from Massey University}, issn = {1176-5283}, author = {Spencer GSG} } @conference {40737, title = {Establishing a flock for gene mapping in wool traits}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {285-288}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A gene mapping flock for wool traits was established by backcrossing of Merino cross Romney (F1) to both parental breeds. The objectives for this flock were to investigate the segregation of wool and skin characteristics in crosses between the Merino and Romney and to investigate methods for the analysis of genetic markers and quantitative trait loci. Analysis of Merino backcross animals showed no evidence of major genes segregating for any of the wool traits studied. The analysis estimated a finite number of genes affecting fibre diameter and bulk. A genetic marker study of these family groups may provide more powerful analysis for the presence of genes affecting wool traits that may be segregating in these crosses. }, issn = {1176-5283}, author = {Wuliji T and Montgomery GM and Dodds KG and Andrews RN and Beattie AE and Turner PR and Rogers J} } @conference {40699, title = {Estimated pasture intake and cow output of single and twin calving beef breeding cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {161-164}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Thirty-eight adult Merino breeding ewes were drenched with Ivomec and given a controlled release anthelmintic (benzimidazole) capsule in August 1992 and December 1993. Mean FEC in the Untreated group peaked over lambing at 600epg in 1992 and 800epg in 1993. Mean FEC in the Treated group remained below 50epg during the active period of the capsule. The Treated ewes had a higher survival rate, were heavier, grew more wool from late July 1993 and weaned more and heavier lambs in 1993 than the Untreated ewes. At a mean Merino wool price of 500c/kg greasy, returns from the increased wool production more than equates with the anthelmintic treatment cost. Increased returns would be gained from improve ewe survival and increased lamb production. }, issn = {1176-5283}, author = {Bown MD and Clayton JB and McMillan WH and Smeaton DC} } @conference {40678, title = {Evaluation of {\textquoteright}CONFIRM{\textquoteright} as a method to verify pregnancy in dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {91-93}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A total of 24 mature rams and ewes (>2.5 yrs) from a line selected for high backfat thickness and an unselected control line were used to investigate the relationship between maintenance efficiency and body composition in mature sheep. Over a 6 week period the sheep were fed daily a pelleted ration at levels to maintain liveweight. At the end of this period the weights of total fat, carcass lean, viscera and of the empty body (fleece free) were estimated from X-ray computed tomographic images. After adjustment for empty body weight the control line required 5\% more feed to maintain liveweight (P<0.05) than sheep from the fat line and males required 19\% more feed (P0.05) than females. After adjustment for differences in either total fat or carcass lean weight, there were no significant difference (P>0.05) in feed requirements between the lines. This indicated that although a genetic change in body composition did alter maintenance feed requirements at maturity, the efficiency of maintaining a unit weight of either fat or carcass lean remained the same. After adjustment for differences in total fat and carcass lean weight, rams still required 11\% more feed than ewes to maintain liveweight. Adjusting for visceral weight had no effect on feed requirements to maintain the mature sheep. It was proposed that differences in the turnover rates of adipose tissue or carcass lean contributes to the higher maintenance feed cost observed for the mature ram. }, issn = {1176-5283}, author = {Henderson KM and Camberis M and Macmillan KL} } @conference {40709, title = {Evaluation of large scale trapping of flies as a means of reducing the incidence of flystrike in lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {193-195}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Atkinson DS and Leathwick DM} } @conference {40683, title = {Evaluation of muscling using Texel and Oxford cross Romney and Hight Romney lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {108-110}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Selection for out-of-season breeding ability could be enhanced if an early indication of the trait was available. The onset of hogget oestrus has been proposed as such a trait and has been examined for 362 ewe progeny coming from early and late-lambing selection lines over 3 years. In each year the early lambing (BV-) hoggets had an earlier (P<0.05) mean date of onset of oestrus than the hoggets from the late-lambing (BV+) line. In 1992 and 1993 this effect was confounded by the season of birth such that nearly all the BV- animals were autumn born (AB) and the BV+ animals born in the spring (SB). In 1993 animals from both lines were produced in both seasons. Their mean day of first oestrus in 1994 (expressed as day of year }, issn = {1176-5283}, author = {Kirton AH and Mercer GJK and Clarke JN and Dobbie JL and Duganzich DM and Wilson JA} } @conference {40695, title = {An evaluation of the Stockpol model}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {145-159}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The potential of large scale bin trapping of flies as a means of reducing the incidence of flystrike was evaluated. Two 5 ha paddocks of similar soil type and pasture species composition, but more than 500 m apart, were used. From Nov. 16 to Dec. 24 flies were trapped in paddock 1 using four 2001 bin traps baited with sheep}, issn = {1176-5283}, author = {Webby RW and McCall DG and Blanchard VJ} } @conference {40754, title = {Ewes for more dollars and flexibility}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {326-327}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {New Zealand{\textquoteright}s national lamb weaning percentage has hovered around 100\% since 1960. This is a disappointing figure considering the number of sheep recording and performance analysis packages that are available to ram breeders. The present "average" NZ ewe probably drops about 1.20 lambs. Assuming 14\% lamb losses from birth to weaning, and 6\% ewes that die or are dry, each ewe mated weans about one lamb that grows at about 200g per day. One obvious way of improving these figures is to increase lambing percentage. For example, introducing 1/4 Finnish Landrace genes into the base flock has the potential to increase lamb drop by 20\%. However, lamb growth rates must also be improved. Incorporating genetically superior milk producing breeds into the dam side as well will also increase lamb growth rates, resulting in lambs with the ability to grow at 250g per day or better. Ewes that produce 30\% less wool than their contemporaries, but at the same time wean an extra 0.2 lambs that are 20\% heavier than the flock average, can increase nett sheep-derived income by around 20\%. The advantages are not just an immediate improvements in gross margins. Additional to this is the increased flexibility in management policies that result from having faster growing lambs that can be weaned earlier to provide better carcass weights or bigger replacements. This flexibility can be enhanced by introducing breeding programmes that utilise terminal sire breeds to further improve profitability. The major advantage of this more productive ewe is that it breaks the 100\% lambing "poverty trap". }, issn = {1176-5283}, author = {Walpole D} } @conference {40712, title = {Faecal nematode egg counts and haematology in Perendale ewes near lambing}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {202-204}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Watson TG and Hosking BC and Morris CA and Hurford AP} } @conference {40692, title = {Feed requirements for maintenance of mature rams and ewes from lines selected for differences in body composition}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {133-136}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Brief communication: no abstract supplied}, issn = {1176-5283}, author = {Ball AJ and Thompson JM and Hinch GN and Fennessy PF and Blakely AR} } @conference {40721, title = {Field scale evaluation of semen diluents for cervical AI in sheep: An attempt at technology transfer}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {232-235}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No Abstract Supplied}, issn = {1176-5283}, author = {Smith JF and Aspinall J and Oliver JE and Murray G and Smith JK and Upreti GC} } @conference {40746, title = {Genetic markers in Inverdale (FecX) sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {307-309}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The Inverdale gene (FecX) is carried on the sheep X-chromosome. Males carrying the Inverdale gene always pass a copy to their daughters, but not to their sons. Females carrying a single copy will pass the gene on to half of their offspring (both male and female). Progeny testing to determine which rams carry the gene, and which offspring have inherited, is time-consuming. Successful management of the Inverdale gene will require a simple, quick inexpensive test to distinguish carriers and non-carriers. A research programme has been initiated to develop a DNA test using DNA markers which will identify carrier animals at birth. Our initial strategy to find suitable markers was to build a map of genes and DNA markers on the sheep X-chromosome as a framework for looking for the Inverdale gene. We have determined the relative positions of twenty genes and DNA markers on the X-chromosome by looking at the pattern of inheritance of the X-chromosome markers in sheep pedigrees established in flocks at Invermay and Tuatapere. We estimate that 80\% of the chromosome has been eliminated in our search to the Inverdale gene. Efforts are now directed towards identifying the particular region of DNA in which the Inverdale gene might lie. Suitable markers must be close enough to the Inverdale gene to be always inherited with Inverdale. Once such markers are identified a test can be developed to determine the Inverdale status of animals. Adaptation of the current techniques will enable DNA to be isolated from a few drops of blood, a mouth swab, or the ear tissue from a newborn animal. }, issn = {1176-5283}, author = {Galloway SM and Hanrahan V and Potts MP and Hill DF} } @conference {40732, title = {Genetic parameters of lifetime wool production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {268-271}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Heritabilities and genetic correlations were estimated from the selected and control lines of a 25-year selection experiment for hogget greasy fleece weight (GFW). The heritability of GFW was higher in the selected than the control line and in female hoggets (0.48) compared with males (0.32). Inter- age genetic correlations were less than unity, and higher in fleece weight selected animals. Average genetic correlations between hogget and adult records were higher in ewe than ram hoggets. Together these parameters gave co-heritability estimates (pooled across lines) for greasy hogget with clean adult ewe fleece weights of nearly half the average magnitude in males (0.21) compared with female (0.36). These results have important repercussions to the design of effective selection strategies for improvement of lifetime wool production. }, issn = {1176-5283}, author = {Clarke JN and Dobbie JL and Hickey SM and Jones KR and Wrigglesworth AL} } @conference {40705, title = {Grazing behaviour of alpaca and sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {183-185}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Differences between breeds in seasonal breeding activity have been linked to seasonal shifts in both LH levels and the magnitude of oestradiol negative feedback. Studies were undertaken to determine the endocrine differences in ewes of the same breed with high or low breeding values (BVs) for date of lambing. Forty-eight ewes (24BV- early lambing and 24BV + later lambing) were selected from the flocks and 16 ewes (8 of each BV class) were ovariectomized (ovx) and implanted with silastic implants containing oestradiol- 17Beta. All ewes were bled 2 x week for a 12 month period commencing in November to provide data on basal LB. The ovx ewes were subjected to rapid sampling (every 20 min for 24 h) using automated sampling equipment, on 5 occasions approximately 1 month after each equinox and solstice in that year and samples were analysed for LH pulse frequency. Basal LH levels showed a seasonal shift with the ovx ewes having a greater amplitude of change than the entire ewes. LH levels in the ovx ewes were lower in November to January, and higher in March, April, May and June; and lower again in August, September, October than in entire ewes. There was no evidence of a major difference in pattern due to BV. In the ovx ewes the values for the BV- animals tended to be lower than those for the BV+ ewes during March through July. At the initial rapid bleed no animals showed pulse activity. In April the BV- group had more pulses per 24 h (6.0 v 2.8). In July there was no difference in proportion having pulses (8/8) nor in the pulse frequency (5.3 v 5.6/24 h). In October the BV- animals had a higher pulse frequency (2.8 v 1.0), while the proportion of animals (3/8) exhibiting pulses was the same. More BV- ewes had pulses in January (6 v 3) and of those with pulses the BV- group had higher frequency (7.7 v 4.7). These data confirm the seasonal shifts in basal LH levels and in LH pulse frequency. Selection for earlier lambing had no effect on the pattern of basal levels. In the ovariectomized ewe the differences in LH pulse frequency due to BV detected in October and final bleed in January were not as marked as expected for the differences in the breeding activity of the two flocks but they confirm that differences in sensitivity to oestradiol 17Beta negative feedback are associated with differences in the onset of breeding season of ewes selected for earlier lambing within one breed. It would appear that selection for earlier lambing has disturbed the association between day length and LH pulse activity and the sensitivity of the pituitary to GnRH. }, issn = {1176-5283}, author = {Sharp P and Knight TW and Hodgson J} } @conference {40733, title = {Growth Hormone (GH) secretory patterns in genetically lean and fat sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {272-274}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The pattern of GH secretion was studied in Coopworth sheep which have been selected for low (Lean) or high (Fat) ultrasonic backfat depth over 15 years. At each of two developmental stages (February and May) Lean and Fat ram lambs were fed ad libitum or fasted for 48 hours (n=6 per treatment). Animals were blood sampled via an indwelling jugular cannula every 10 minutes for six hours, then slaughtered and the pituitary glands removed and weighted. Mean GH was greater for Lean than Fat animals (2.82 versus 1.42 ng/ml, p<0.001), in February than in May (2.47 versus 1.62 ng/ml, p<0.001) and for fasted than fed animals (2.48 versus 1.62 ng/ml, p<0.001). Analysis of GH secretory patterns showed that peak frequency for Lean animals was more than twice that for Fat animals (2.64 versus 1.17 peaks/6 hours, p<0.001). There was no difference in the peak amplitude. In line with their higher GH concentrations, Lean animals had significantly heavier pituitaries than Fat animals (0.74 versus 0.52 g, p<0.001). Selection for leanness in Coopworth sheep has altered the GH secretory pattern of the animals. The pituitary weight may explain some of these changes in GH secretion. }, issn = {1176-5283}, author = {Francis SM and Veenvliet BA and Littlejohn RP and Stuart SK and Suttie JM} } @conference {40745, title = {Hormone secretion patterns associated with increased ovulation rates or with ovarian dysfunction in Inverdale (FecX) ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {304-306}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Ewes that are heterozygous (I+) carriers of the Inverdale gene (FecX) have increased ovulation rate, whereas ewes that are homozygous (II) for the gene are infertile and have {\textquoteright}streak{\textquoteright} ovaries in which normal follicle development does not occur. A proportion of ewes with streak ovaries develop structures that have some characteristics of ovarian tumours. We have monitored the growth of ovarian structures and (c) assess the effectiveness of using hormone concentrations to identify the genotype of individual ewe lambs. No differences in hormone secretion related to differences in ovulation rate were evident between I+ and non-carrier (++) Inverdale ewes (mean ovulation rates 3.1+/-0.22 ng/ml) nor inhibin concentrations of gonadotrophins were consistently elevated (FSH 16.9+/-1.8 ng/ml; LH 4.5+/-0.5 ng/ml; N+14) and were comparable to those observed in ovariectomised ewes. In contrast, inhibin was always undetectable (<3.0I.U./ml). These patterns of hormone secretion often change markedly when ovarian structures develop, with inhibin concentrations increasing acutely, which in turn causes FSH levels to fall. To assess the potential of using these differences to identify II genotype, Inverdale ewe lambs were blood-sampled at two, five or seven months of age. Over 95\% of II Inverdale ewe lambs had genotype assigned correctly (confirmed by laparoscopy) on the basis of plasma FSH concentrations alone. }, issn = {1176-5283}, author = {McLeod BJ and Kyle SE and Ramsay MR and Manley TR} } @conference {40735, title = {Impact of breeding technologies on the genetic gain of Merino flock}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {278-280}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Several breeding technologies are available to sheep breeders for increasing the rate of genetic progress in their flocks. The relative merits of these technologies depends on the selection objective and other breeding and management circumstances. This paper investigates the effects of artificial insemination (AI), progeny testing and an open-nucleus flock, on a breeding programme for fine woolled merinos. The selection objective was to decrease Mean Fibre Diameter (MFD) while maintaining Clean Fleeceweight (CFW). Two population structures were considered: a)Maintaining a closed nucleus flock of 1000 breeding ewes b)Operating an open-nucleus breeding scheme sourcing a proportion of replacements from the progeny of 5000 contributing ewes. For each structure, the benefits of AI and progeny testing were investigated individually and in combination. For the range of options considered, selection resulted in a reduction of one micron in MFD every three to five years, with no reduction in CFW. All other things equal progeny testing decreased the genetic progress possible by 0.04-0.06 u/year. An open-nucleus breeding scheme increased the rate of genetic gain by 0.06 u/year with progeny testing or 0.03 u/year in the absence of progeny testing. AI increased genetic progress by 0.06 u/year. The combination of AI and an open nucleus provided the maximum potential rate of genetic gain (0.36 u/year). To optimise the age structure for this combination of breeding technologies, the nucleus flock comprised 60\% two-tooth ewes. These results describe the impact of breeding technologies on the rate of genetic gain. To determine their cost-effectiveness, the marginal genetic gain provided by any individual technology must be weighed up against the costs and management constraints that the technology imposes. }, issn = {1176-5283}, author = {Sherlock RG and Garrick DJ} } @conference {40752, title = {Importing a sheep which offers more - the East Friesian}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {321-323}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The development of more productive sheep is possible through selection within breeds and crossbreeding or by importing new genetic material. The introduction of new breeds involves complex and time consuming development of import protocols, and health testing of source flocks and individuals prior to entry into NZ. Repeat health testing of sheep (and/or recipient ewes receiving embryos) and long scrapie surveillance protocols are required prior to release. Of the new breeds, the East Friesian with large body size, high fecundity and milk production, leanness and moderate wool production will likely prove the catalyst for a sheep milking industry, and will be a component of a productive meat and wool dam. Early data confirm that the East Friesian offers considerable opportunities in these areas. }, issn = {1176-5283}, author = {Allison AJ} } @conference {40730, title = {Induction of early post-calving ovulation and oestrus in suckled beef cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {261-264}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The aim of this study was to compare the efficacy of exogenous progesterone, either without or with a single injection of gonadotrophin releasing hormone (GnRH), at initiating early post-calving ovulatory and oestrous activity. Six days (d)after the first post-partum follicle had attained dominance cows were allocated to either an untreated control group; treated with a progesterone-impregnated CIDR}, issn = {1176-5283}, author = {McMillan WH and Hall DRH and Oakley AP} } @conference {40743, title = {Industry use of the Inverdale gene (FecX)}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {298-300}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The Inverdale gene (FecX) offers the sheep industry the potential to markedly increase production at little cost. However, the characteristics of the gene mean that appropriate breeding structures are essential. The recommended structure is a stratified crossbreeding system. The three tier breeding structure consists of: (1) a ram breeder producing rams known to carry the Inverdale gene; (2) a ewe breeder producing carrier ewes by mating carrier rams across dual purpose breed ewes; and (3) a lamb producer who mates a meat breed ram with carrier ewes to produce lambs for slaughter. Some farmers may choose to have two, or all three tiers on a single property. If the gene was used to maximum extent possible in Romney and Romney derived breeds, some 40\% of all breeding ewes would contain a single copy of the gene and these would produce 31\% more lambs for sale per ewe mated. Conservative estimates of the benefits to the New Zealand farmer are approximately $29m per annum. }, issn = {1176-5283}, author = {McEwan JC and Davis GH and Fennessy PF and Dodds KG} } @conference {40651, title = {Influence of milking frequency and feeding level on plasmin activity and casein degradation in milk}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {9-11}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Wool samples from 28 Merino wethers, 31 Corriedale ewes, 37 Perendale ewes and 30 Coopworth ewes were examined for propensity to develop yellow discolouration in relation to the mean fibre diameter and its variability. The propensity of wool to develop yellow discolourations was estimated by two techniques, namely, an incubation technique which measures the colour developed in the wool fibre during an incubation in the laboratory, and the predictive technique described by Aitken et al., 1994. Correlations between propensity to yellow (Y-Z) and mean fibre diameter were low in the Corriedale, Perendale and Coopworth samples, but high in the Merinos. Correlations between propensity to yellow and standard deviation of fibre diameter were also low in the Corriedales, Perendales and Coopworths, but moderate in the Merinos. The correlations between Y and Z and the fibre diameter statistics following similar trends to those for Y-Z. All correlations between propensity to yellow and coefficient of variation of fibre diameter were low. Thus while the propensity to discolour during growth is positively related to fibre diameter in fine wool, no such relationship exists in medium and coarser wool. This provides a further reason for Merino breeders to produce a fine fleece type. }, issn = {1176-5283}, author = {Prosser CG and Nicholas G and Stelwagen K and Lacy-Hulbert SJ and Woolford MW and McFadden TB} } @conference {40676, title = {Influence of once daily milking and restricted feeding on milk characteristics in late lactation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {85-87}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Ninety 1991 drop Merino wethers, thirty from each of fine, medium and strong wool strains were randomly allocated on the basis of stratified live weight within strains to one of three treatment groups. The first treatment involved grazing ample good quality natural or irrigated pasture (H) throughout the experiment so that the sheep remained in good to excellent condition throughout. The second involved grazing restricted amounts of pool quality nature pasture (L) throughout the experiment so that the sheep remained in backward store condition. As a control, a third group (C) grazed natural pasture such that the sheep subject to seasonal variations in pasture quality and quantity and their condition varied from store to forward store throughout the experiment. Intake was estimated on two occasions; in February 1994, and July 1994, by dosing with controlled-release alkane capsules. Pasture samples were taken at these times based on observation of sheep grazing patterns. However, later analysis showed that the pattern of alkanes in the collected herbage was different to the alkane pattern in faecal samples, indicating that the herbage samples were not truly representative of the herbage consumed by the sheep, particularly at the summer sampling. Actual intake (AI) (expressed as kgOM/day }, issn = {1176-5283}, author = {Lacy-Hulbert SJ and Woolford MW and Bryant AM} } @conference {40687, title = {Inter-muscle variation in the calpain system of red deer:- implications for meat tenderness}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {120-123}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A grazing trial using 24 Red and 24 Hybrid (0.75 Red; 0.25 Elk) deer weaners was conducted from 1st March to 12th December 1993, to compare the feeding value of chicory (Cichorium intybus L) with that of perennial ryegrass (Lollium perenne)/white clover (Trifolium repens) pasture for increasing venison production by one year of age. The deer were rotationally grazed using dry matter allowances of 6, 6 and 7 kg DM/head/day in autumn, winter and spring respectively. Relative to deer grazing pasture, deer grazing chicory had higher voluntary feed intake (VFI), slightly lower grazing (ie. eating) time and substantially lower ruminating time. Hybrid deer had faster liveweight gain (LWG) than Red deer and were heavier at the end of all seasons (P<0.01). LWG was greater on chicory than on perennial ryegrass/white clover pasture during autumn (P<0.01) and there were forage x genotype interactions for liveweight at the end of autumn and spring, with Hybrid deer (especially stags) being heavier when grazed on chicory. Carcass weight for Red and Hybrid stags was 64.9 and 73.0 kg when grazed on chicory and 56.6 and 57.0 kg when grazed on perennial ryegrass/white clover pasture. Grazing chicory advanced the date of first cut velvet antler by 28 days and increased the weight of total (first cut+regrowth) velvet antler. It is concluded that grazing chicory increased venison production, especially in Hybrid stags with increased growth potential, and increased velvet antler production. }, issn = {1176-5283}, author = {Dobbie PM and Singh KK and Thomson BC and Mercer GK and Bass JJ and Speck PA} } @conference {40747, title = {Inverdale as a model}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {310-311}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The Inverdale gene (FecX) is extraordinary. Located on the X- chromosome, it increases ovulation rate in the heterozygous state, but in the homozygote the ewe has undeveloped or "streak" gonads and is sterile. The phenotype is almost certainly due to the action of the gene in early embryonic/foetal development. The Inverdale may be valuable model for investigation of similar phenotypes in other species, especially the human female. Identification of the gene itself will enable substantial progress in understanding mechanisms of ovarian and follicle development. However, even without knowledge of the specific gene function, there are the areas where the phenotype itself may be of real value. Two such areas are the "tumour-like" structures in the homozygote as a model for ovarian tumours and the "steroid-free" environment of the homozygote as a model for investigating the regulation of seasonality in sheep. }, issn = {1176-5283}, author = {Fennessy PF} } @conference {40748, title = {The Inverdale prolicacy gene: contract summary}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {312-313}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {none supplied }, issn = {1176-5283}, author = {Duffy RG} } @conference {40738, title = {The Inverdale prolificacy gene in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {289}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {none supplied }, issn = {1176-5283}, author = {Davis GH} } @conference {40742, title = {Living with the Inverdale gene (FecX) in a Romney flock}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {296-297}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {This paper discusses a Romney flock where the Inverdale gene was identified in 1993, but it almost certainly traces back to a 1968-born ewe that had triplets in four successive lambings. It appears that the first Inverdale ram used in the flock was a triplet son of this ewe, born in 1970, because several ewes born in 1972 produced triplets or quadruplets. The breeding programme has been based on all ewes being given the same treatment, and thus multiple rearing ewes had to perform well if their progeny were to be selected. Carrier ewes have the range of qualities present in the larger population and the same management practices, production objectives and procedures can be applied to them as to non- carrier sheep. The only difference is the enhanced prolificacy and the management requirements that may impose. Records show that they maintain condition well and have a long life expectancy. }, issn = {1176-5283}, author = {Hanna MM} } @conference {40716, title = {Maternal antibodies and immune responsiveness in growing lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {214-217}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McQuoid MR and Hodgkinson AJ and Hodgkinson SC} } @conference {40703, title = {Metabolic changes of cadmium and zinc in kidney and liver tissue during foetal development in Romney and Merino sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {176-178}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Diseases affecting mucosal surfaces, especially gastrointestinal disorders, cause high mortality rates in young domestic livestock. Hyperimmune milk products, using milk secretions from ruminants immunised systemically with enteric pathogens, have been shown to confer passive immunity against such disorders but the results are variable. To study the type and titre of immunoglobulin (Ig) classes produced in milk secretions after immunisation with gut pathogens, we have developed ELISAs for the estimation of ovine IgG and IgA antibodies directed against E. coli. Utilising an indirect ELISAs technique, the method involved coating antigen onto microtitre plates then sequential addition of test sample dilutions (containing primary antibody), anti-class-specific antibody and anti- species horse radish peroxidase labelled antibody. Colorimetric end point detection employed 3, 3}, issn = {1176-5283}, author = {Rounce JR and Lee J and Treloar BP and Grace ND and Sinclair BR} } @conference {40656, title = {Mitogenic activity of lamb mammary fat pad in vitro is distinct from that of mouse mammary fat pad}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {23-25}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Apple pomace, a by-product of the apple juicing industry, was assessed as a supplementary feed for lactating dairy cows during autumn. Cows were offered a base diet of 6 kg DM/cow/day from grazed pasture and one of three supplement treatments; control (7 kg DM/cow/day grass silage); apple pomace (AP) (3 kg DM/cow/day grass silage plus 4 kg DM/cow/day fresh AP); and AP+"balancer" (3 kg DM/cow/day grass silage plus 3 kg DM/cow/day fresh AP plus 1 kg DM of by-pass protein meal supplement ("balancer"). Treatment groups each comprised 10 mixed age Friesian-Jersey crossbred cows which were fed the supplement(s) in their respective groups in two equal portions following morning and evening milkings. Groups were grazed independently on similar pastures between these times. Herd test milk yields over the 28 day supplementary feeding period were greater for the AP and AP+"balancer" groups (14.1 \& 14.7 litres/cow/day, respectively) than for the control group (12.1 litres/cow/day; P<0.001). Milk protein yields were lower for the control than the two AP groups (0.43 vs 0.54 \& 0.57 kg/cow/day for control, AP and AP+"balancer", respectively; P<0.01). Yields of milkfat (0.58 vs 0.70 vs 0.77 kg/cow/day) and milksolids (1.01 vs 1.24 vs 1.34 kg/cow/day) differed between all three treatment groups (P<0.05). Cow condition and bodyweights were similar between the three treatment groups at both the start and end of the trial. Apple pomace was therefore shown to be a useful supplement for dairy cows in late lactation. }, issn = {1176-5283}, author = {Hovey RC and McFadden TB and MacKenzie DDS} } @conference {40736, title = {MOET in ultrafine Merinos: An experimental evaluation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {281-284}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Results of experimental MOET programme in elite ewes selected from within an ultrafine Merino flock are presented. Of the treated ewes, 60\% provided transferable donors with a mean of 16.7 ovulations and 10.4 embryos recovered, 7.8 embryos transferred, 3.9 lambs born and 3.1 lambs weaned per donor ewe. The wool produced by hoggets from this elite embryo transfer group was 0.9 um (P0.01) finer than that from their contemporaries in the ultrafine selection flock and 2.5 um (P0.01) finer than a random Merino control group. The improvement in fibre diameter was better than expected from the selection differentials, but not significantly so. The h2 estimates for liveweight, clean fleece weight, fibre diameter and yield in three flocks of fine woolled Merinos were 0.50, 0.32, 0.39 and 0.58 respectively. The MOET programme was successfully applied to increase the number of progeny from elite ultrafine Merino ewes. }, issn = {1176-5283}, author = {Wuliji T and Aspinall J and Land JTJ and Shackell GH and Dodds KG and Andrews RN and Rogers J} } @conference {40658, title = {Monitoring wool fibre diameter and length changes using gel emulsion autoradiography}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {28-30}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The ability of New Zealand cows to achieve high milksolids production has been well documented, but less than 1\% of New Zealand dairy herds consistently achieve more than 350 kgs milksolids (MS) per cow per season. A survey was undertaken to characterise seasonal dairy farms in the lower North Island that had achieved an average production of at least 348 kg MS per cow over three seasons (n=31 farms from 1162 suppliers). Thirty of these farmers were interviewed. The farmers averaged 51 +/- 11 years of age and had 31 +/- 10 years of dairy farming experience. The average herd size of 164 (range 52-515) cows was milked on 66.5 hectares (2.48 cows/ha). Milksolids production of 386 +/- 28 kg per cow was achieved from an average lactation length of 274 +/- 10 days. Peak MS production ranged from 1.16 to 2.09 kg/day. Production equated to 881 kg MS/ha and 56,800 kg MS/farm. Friesian and Friesian x Jersey cross cows predominated (87\% of herds). Hay, silage, nitrogen, and grazing young stock off the milking area were used to increase the feed available to the milking herd. In pasture equivalent terms this equated to 315 kg DM/cow as hay, 342 kg DM/cow as silage and 198 kg DM/cow from nitrogen-boosted pasture. Concentrates and summer crops were each used by nine farmers to provide additional feed to their herds. There was a significant correlation between total feed inputs and days in milk )r+0.49, P<0.01). Per cow production was associated with soil fertility (r=0.48, P<0.01), and peak milk production (r=0.68, P<0.001). A wide range of management systems were used to achieve high per cow production, but a common aim was to feed cows as well as possible. }, issn = {1176-5283}, author = {Friend MA and Robards GE} } @conference {40756, title = {Mount Linton wools - now and beyond 2000}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {330-331}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {At Mount Linton Station the emphasis in wool production is moving away from the concept of quantity alone, towards a philosophy of quantity and quality. The quality component is being driven by end-user requirements. With this in mind we are working closely with a specific company, Summit Wool Spinners in Oamaru. We are also investigating the possibilities for producing specialty crossbred wools, examples of which include the creation of "branded" lines produced under an appellation standard and "chemical-free" wool. The demands of the manufacturer are having an increasing impact on the genetics and ram breeding elements of Mount Linton{\textquoteright}s wool production system. The change of emphasis towards quality wool production and the genetic requirements for parasite resistance resulting from reduced pesticide use, will put increasing pressure on our ram-breeding enterprises. By capitalising on the large numbers of animals we have available we can meet the challenge of concentrating on producing high quality wool products for specialist markets. To achieve this, the linkage between the farm and the end-user is vital to the future of Mount Linton Wools. }, issn = {1176-5283}, author = {McGregor A} } @conference {40689, title = {Near-infrared reflectance analysis of intramuscular fat in beef}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {124-126}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {In adult sheep, cadmium (Cd) accumulates in both liver and kidney tissue in an age dependent manner. To quantify the accumulation of Cd in the developing foetus and investigate the relationship with the Cd status of the maternal parent, liver and kidney samples were collected from both Romney and Merino foetuses, approximately fortnightly, from 60 days after conception up to parturition, and from the suckling lamb, weekly over three weeks. Matching liver and kidney samples were also obtained from the dam. Tissue sub-samples were analysed for metallothionein-mRNA by dot blot hybridisation of total RNA extracts to assist in identifying regulatory aspects of Cd accumulation in hepatic foetal tissue and any relationship with Zn. Cadmium concentrations (means }, issn = {1176-5283}, author = {Smith DR and Smith NB and Muir PD} } @conference {40749, title = {New sheep: a catalyst for change}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {315}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Since the completion of the latest GATT negotiations a lot of reflection has been devoted to new opportunities that will be offered to New Zealand{\textquoteright}s primary industries, but there is a more subtle issue that is less frequently mentioned. The effects of competition will be felt by every sector of every industry. In a country committed to freer trade and in a world increasingly moving in the same direction, no industry will be able to lay claim to more land, water, research resources or investment than it can justify by way of return. For the sheep industry, this means looking beyond mere survival, towards shaping the future by making the best possible use of resources devoted to it. Sheep farming must become more than just a default land use. }, issn = {1176-5283}, author = {Fennessy PF} } @conference {40751, title = {New sheep - a catalyst for change}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {318-320}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {New sheep may be alternative breeds brought in from other environments, new synthetic breeds developed by crossbreeding or as specific crossbred combinations, or new strains of existing breeding populations developed by selection for production traits, identifiable genes or gene complexes. Changing gene frequency is the main underlying feature of all these approaches to genetic improvement. Selection of parents is the common operational ingredient. New products have been a major factor in changing the breed structure of our sheep industry. New more productive breeds have also been produced utilising the complementary features of existing breeds, but with little widespread development of crossbreeding systems based on first cross ewes. Improved reproductive rate from selection or use of new fecund genotypes offers much scope for specialised production of quality market lambs, especially when stratified production a major stimulus to the improvement of terminal sire breeds. They are re-focusing the balance of emphasis on lamb growth and carcass and encourage a search for unique genetic effects on meat quality traits. }, issn = {1176-5283}, author = {Clarke JN} } @conference {40653, title = {Nitric oxide and the control of mammary blood flow}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {14-16}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {This study monitored the behaviour of calves docked with a rubber ring with or without local anaesthesia. Forty five 3 to 4 month old Friesian heifer calves were divided equally into three groups viz control (C), docked following local anaesthetic (L). After treatment the calves were returned to a paddock where their behaviour was monitored continuously for 5 hours with scan sampling every 10 minutes. Standing, walking, grazing and ruminating behaviours were similar in the 3 groups. Within 30 minutes of the treatment tail shaking, and vocalization occurred in 10 and 5 R calves and of them 2 calves continued to tail shake and vocalise for a further 60 minutes. Tail shaking and vocalisation occurred in 7 and 5 of the L calves respectively at 150 minutes. Two of these calves vocalised at 180 minutes and one at 210 minutes following treatment. C calves did not shake their tails or vocalise. These observations suggest that milk distress was experienced by approximately two thirds of docked calves. }, issn = {1176-5283}, author = {Lacasse P and Farr VC and Davis SR and Prosser CG} } @conference {40701, title = {Nutritive value of chicory (Cichorium intybus L) for venison production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {169-173}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Results from farmlet studies indicated that anthelmintic treatment of ewes during pregnancy virtually eliminated ewe parasite faecal egg counts and lead to significantly higher lamb weaning weights. The objective of this study was to develop strategies to enable the rearing of lambs within minimal anthelmintic administration. There were four farmlets, with paired units on dry and irrigated land (5 and 6.4 ha respectively) with mixed aged flocks of 60 or 80 ewes respectively. One flock on each pair of farmlets, termed treated flock, were treated with a continuous anthelmintic release bolus in March prior to mating and again 100 days later in June. The control flock of each pair was given an oral anthelmintic post-lambing in line with local farmer practice. In March of both years faecal egg counts (FEC) were similar for all flocks and averaged between 40 and 160 eggs per gram (peg). For bolus treated flocks average FEC declined to 0 after treatment and remained below 32 peg until September. In contrast the control flocks had significantly higher (P<0.001) egg counts at levels of 50 to 600 epg throughout winter, but exhibited the classic periparturient peak in 1993 only. From October all flocks had similar FEC}, issn = {1176-5283}, author = {Kusmartono and Barry TN and Wilson PR and Kemp PD and Stafford KJ} } @conference {40744, title = {Ovarian characteristics in Inverdale ewes heterozygous (I+) and homozygous (II) for the Inverdale gene (FecX)}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {301-303}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The Inverdale gene (FecX) affects ovarian development, during both foetal and adult life. There is evidence for affects on germ-cells, the follicle and the corpus luteum. In I+ewes, follicles ovulate at a small diameter with fewer granulosa cells and the resulting corpora lutea are individually smaller compared to those in control (++) animals. This appears to be due to the granulosa cells in I+ follicles being more responsive to follicle-stimulating hormone (FSH) and acquiring receptors for luteinising hormone (LH) earlier than in cells from ++ ewes. These differences between I+ and ++ ewes in ovarian characteristics occur in the absence of any obvious differences in the peripheral plasma concentrations of FSH and LH or the ovarian secretion rates of inhibin, oestradiol and progesterone. In II animals, ovarian follicular growth is impaired at the primary stage of growth during foetal, neonatal and adult life. No normal follicles beyond this stage of growth have been observed. II animals also have castrate levels of FSH and LH and undetectable plasma levels of ovarian steroid or inhibin. In ~35\% of II animals, abnormal surface-visible structures have been observed with a morphology consistent with that of a sertoli-cell or sex-chord stromal tumour. These structures, which secrete inhibin, appear to develop from clusters of oocyte-free follicles. }, issn = {1176-5283}, author = {McNatty KP and Smith P and Hudson NL and Lun S and Heath D and Shackell G and Corrigan K} } @conference {40649, title = {Partitioning of milk accumulation between cisternal and alveolar compartments of the bovine udder: relationship to production loss on once-daily milking}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {5-6}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Colour is an important characteristic affecting wool price. Canary yellow wool incidence is low in dry years but individuals can be classified according to their degreee of susceptibility to wool yellowing based on results of wool incubation test. Australian Merino, Corriedale and New Zealand Romney populations were tested. A number of 603, 1269 and 476 progenies and 21, 52 and 24 sires were used for these populations, respectively. Susceptibility to wool yellowing (YPC), greasy (GFW) and clean fleece weights (CFW), yield (Y) and mean fibre diameter (MFD) were analysed in a sire model. Heritability values for YPC were 0.21+/-0.11, 0.28+/-0.08 and 0.19+/- 0.07 for Merino, Corriedale and Romney, respectively. Genetic correlations between YPC and other traits were 0.04+/-0.31 with GFW, - 0.10+/-0.31 with CFW, -0.11+/-0.29 with Y and 0.51+/-0.29 with MFD for Merinos; 0.30+/-0.18, 0.17+/-0.19, -0.12+/-0.18 and 0.33+/-0.19, - 0.12+/-0.18 and 0.33+/-0.19 for Corriedale, respectively, and 0.77+/- 0.22, 0.44+/-0.31, -0.70+/-0.35 and 0.25+/-0.30 for Romney, respectively. Phenotypic correlations were negligible among this traits for these three populations, except for YPC and Y (-0.33+/-0.10). Selection strategies to reduce wool yellowing susceptibility will differ between genotypes. Low frequency of susceptible sheep in Merino population showed little justification for including YPC in genetic programmes for this particular breed only. }, issn = {1176-5283}, author = {Farr VC and Davis SR and Copeman PJA and Carruthers VR and Knight CH} } @conference {40681, title = {Plasma cholesterol and triglyceride concentrations in yearling Angus cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {101-103}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The Stockpol model was designed for decision support on New Zealand sheep and beef cattle farms. It indicates the biological feasibility of a livestock system and provides the opportunity for users to test alternative livestock policies. An evaluation of the Stockpol model was made using 44 data sets from farmlet trials at Gore, Ballantrae, and Whatawhata Research Centres and data from Massey University{\textquoteright}s Riverside farmin the Waiarapa. These data covered a range of sheep and beef finishing systems. The main test compared the measured pasture growth rate with that required by Stockpol to predict the monthly pasture cover recorded in the data. Measured and required pasture growth rates differed significantly (<0.01) in July, August and September. The model was conservative and required an average of 5.1 kgDM/ha/day more growth over these months than was measured. In other months the differences were small and non significant. When animal demand was adjusted to mimic pasture cover, adjustments of minus 22\% from July to September were required. Overall it was considered tha Stockpol can be used with confidence for analysing options for farmer decision making. Areas for further improvement of Stockpol have been defined as the pasture growth model in early spring. Aspects of the animal demand in early spring also need to be tested more vigorously. The evaluation emphasised the importance of consistent input data for use in models. For example, the pasture measurement technique was different at each of the four sites studied. This may explain some of the variation between predicted and measured data.}, issn = {1176-5283}, author = {Morris CA and Cullen NG and Upreti GC} } @conference {40648, title = {Presidential address: some advantages of corporate animal production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {1-4}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Staple tenacity is an estimate of the peak force to break a staple of a certain cross-sectional area at the point of break. Staple strength is a measure of peak force to break a certain weight of staple. Using the density of wool and the length of staple broken, both estimates can be converted to force per unit linear density (N/ktex). The relationship between these two estimates was examined. Midside wool samples were collected at shearing from 164 ewe hoggets from lines of New Zealand Romneys that have been selected for or against staple tenacity, and a randomly selected control line. Five staples from each sample were measured for staple strength and staple tenacity. This was accomplished by defining the cross-sectional area at the break point, breaking the staple to estimate peak force and then cutting the portion of the staple from between the jaws and determining the weight of clean wool after scouring. The High staple tenacity line had a significantly higher staple strength (P<0.001) and staple tenacity (P<0.001). Although a similar weight of greasy wool was removed from between the jaws for each selection line (P=0.336), the weight of clean wool was significantly greater in the High staple tenacity line (P=0.003). Covariate analysis revealed that the fitted relationships between staple strength and staple tenacity for the three selection lines had similar slopes (P=0.822) but significantly different intercepts (P=0.029). Staple strength is thus biased relative to staple tenacity in these lines, because of the differences in weight of wool between the jaws, for staples which are all the same cross-sectional area at the point of break. Staple tenacity is therefore more useful for some purposes than staple strength and vice versa, and care should be taken when drawing comparisons and conclusions and when considering which to use. }, issn = {1176-5283}, author = {Nicoll GB} } @conference {40707, title = {Quantitative indicators of stress in stress-susceptible and stress- resistant breeds of pigs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {187-189}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Spencer GSG} } @conference {40654, title = {Regulation of lactose production by ovine mammary acini in culture}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {17-20}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Five sets of rising five year old Holstein-Friesian non-lactating identical twin cows were studied from February to April 1994. One member from each twin pair had been tail docked at 18 months of age while the other member had its tail intact. The animals were observed weekly at three different times of day; 7am, 12 noon and 3pm. At low fly levels there were no significant differences in the frequencies of either front (eg. leg stamping) or rear (eg. tail flicking) focused fly- induced behaviours between the two treatments. At high fly levels there were no significant differences in front focused behaviours but the docked animals performed significantly more rear focused behaviours than the non-docked cows (eg. 96 vs 34 tailflicks at 12 noon, p<0.05). The adrenocorticol responses to intravenous injection of 0.05mg ACTH (Synachthen, CIBA-GEIGY) or saline was assessed four times throughout the experiment. The animals were blood sampled at time - 1min, 50 and 120 min relative to the time of injection of ACTH or saline. There were no significant differences in plasma cortisol concentrations in response to ACTH injection between treatments. Tail docked cows had elevated levels of fly induced behaviour but did not have an altered adrenal cortex function. This suggests that behaviour is a more sensitive indicator of the effects of fly predation than adrenal response to ACTH. Sensitive physiological indicators of chronic stress need to be developed for the assessment of husbandry practices. }, issn = {1176-5283}, author = {McFadden TB and Callaghan MR and Davis SR} } @conference {40686, title = {Relationship between bioimpedance and muscle mass in chilled lamb carcasses}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {117-119}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {East-Mediterranean natural pastures are characterised by extreme seasonal variation in nutritional value. High quality green standing pasture is available only during the rainy season (Dec-May), whereas during the rest of the year the standing pasture is dry and of low quality. The main objective of this study was to investigate the potential of increasing weaning rates and weaning weights on a commercial beef suckler herd under the above conditions. The main 3 means to achieve this were: (I) increasing stocking rate, (ii) intensive trough-feeding, during the dry pasture season, of rations based on recycled wastes, and (iii) short calving periods. Main input-output data in the 1st and 10th year of the study, respectively, were as follows: herd size: 424, 624 cows; stocking rate 0.19, 0.29 cow/ha of pasture; trough-fed ration; 1, 2 metric tons DM/cow/year; energy in trough- fed ration: 7.5, 8.8-9.6 MJ ME/kg DM; percent cows calving in the first 2 months of the calving season (Aug. + Sept.): 35, 89; percent cows weaning (of exposed to mating bulls): 73, 86; avg. calf weaning weight 206, 259 kg LW; total weaned calf crop: 64, 138 metric ton LW/year. These data present a potential model for improving the efficiency and increasing the volume of range beef production under Mediterranean-type pasture conditions. Studies are in progress on intensive beef production (I) by suckler herds in full confinement - fed year-round on rations composed mainly of recycled wastes, (ii) by dual-purpose cattle - in dairy herds under milk quotas, and (iii) under desert conditions based on grazing or trough-feeding forage irrigated with saline water and/or purified recycled sewage water. }, issn = {1176-5283}, author = {Hopkins DL and Hegarty RS} } @conference {40659, title = {The relationship between cortical structure and fibre diameter in primary and secondary wool fibres of yearling Perendale sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {31-34}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The effects on bloat of herbage mass and of removing Poa from pasture was investigated. Twelve paddocks were paired on pasture composition in autumn and Poa seedlings were removed from one paddock in each pair. Each paddock was halved and two levels of herbage mass were established. The resulting treatments, high herbage mass with Poa (H+P), high mass without Poa (H-P), low mass with Poa (L+P), and low mass without Poa (L-P), were grazed by four groups of six cows of high susceptibility to bloat over four 12-day periods in spring. Herbage mass was 814 kg DM higher (P<0.001) before grazing and 518 kg DM/ha higher (P<0.001) after grazing on H versus L.Poa content (\% DM) was higher and white clover in +P compared to -P (Poa 11 and 2\%, P<0.001; clover 16 and 26\%, P<0.001). The average bloat score was highest on L-P and least on H+P and was 2.4 times greater on L than H and 5.5 times greater on -P than +P. Results indicated that bloat could be manipulated by altering herbage mass, but any effect on bloat of Poa was confounded with changes in white clover content. }, issn = {1176-5283}, author = {Dick JL and Sumner RMW} } @conference {40702, title = {The relationship between daily Se intakes and blood Se concentrations in pregnant dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {174-175}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {In ruminants protection against environmental pathogens in the early post-natal period is largely dependent on passively-acquired immunity from maternal colostrum since evidence suggests placental transfer of antibody does not occur. Our overall aim is to develop antibody based treatments for protection of neonatal animals. In this study we have re-examined aspects of maternal antibody transfer to offspring especially in the light of recent evidence that feeding specific antibodies to neonatal rats decreases subsequent immune responses to the corresponding antigen. In experiment 1, pregnant ewes immunised with model antigen (human growth hormone) were terminated at 135 days gestation and blood samples collected from the ewe and fetus. Analysis of fetal plasma by antibody dilution/tracer binding assay procedures produced no evidence of antibody transfer to the fetal circulation via the placenta. In a further study the kinetics of specific antibodies were examined in lambs from immunised ewes. One group of lambs was permitted to suckle from the ewe for the duration of the trial (40 days) whereas the other group was permitted initial sucklings only, separated from the ewe 24 hours post partum and then fed a milk substitute. Analysis of specific antibodies titres revealed a very similar trend in both the amount of antibody transferred to lamb plasma and its persistence with the half-life for both groups calculated at approx. 13 days In the second experiment lambs from ewes immunised during pregnancy against E.coli and fed specific antibodies via maternal colostrum as neonates were compared to a matched control group of lambs derived from non-immunised ewes for subsequent immune responses against the same antigen. Peak antibody titres as analysed by ELISA were lower in lambs from immunised ewes than in control group lambs (mean titre (-log 10) 5.29 }, issn = {1176-5283}, author = {Grace ND and Mills AR and Death AF} } @conference {40665, title = {Relationship between wool colour and fibre diameter in four breeds of sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {50-53}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The influence of season on the composition of milk from approximately 200 Beta-lactoglobulin (B-LG) AA and 200 B-lactoglobulin BB phenotype cows was determined for the 1992/93 and 1993/94 seasons. Marked seasonal fluctuations were observed in all components measured: protein, casein, whey protein, ash, lactose, alpha-lactalbumin, B-LG, alpha/s- casein, Beta-casein, k-casein (k-CN), bovine serum albumin, calcium, magnesium, sodium, potassium, chloride, and phosphate. Significant differences in composition were observed between the AA and BB phenotype milks, with the Beta-LG BB phenotype milk containing more total protein, casein, fat, and total solids, whereas the Beta-LG AA phenotype milk contained more whey protein, Beta-LG, and had a higher ratio of Beta- LG to k-CN. Such differences in composition could have a marked effect on the physicochemical characteristics of these milks. The higher concentration of casein found in the Betal-lactogloblin BB type milk should make this milk type more suitable for the manufacture of cheese and casein. }, issn = {1176-5283}, author = {Reid TC and Botica KJ} } @conference {40693, title = {The relationship between wool production, live weight and liveweight change in four specialty carpet wool breeds, Romneys and Merinos}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {137-140}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Changes in plasma concentrations of cortisol, ACTH and free fatty acids were evaluated as quantitative indicators of stress in pigs of stress- susceptible and stress-resistant breeds. The changes in these concentrations following loading, transport and subsequent resting in lairage were examined. Resting concentrations of cortisol were higher (P<0.01) in stress- susceptible Pietrain pigs (44.0 }, issn = {1176-5283}, author = {Champion SC and Robards GE} } @conference {40690, title = {The relative intake of three Merino strains under different grazing regimes estimated using alkane technology}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {127-129}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {As part of a study measuring the effect of a variant of insulin-like growth factor-1 (long-arg3-IGF-1; LR3IGF) on tissue amino acid utilisation in sheep, changes in plasma Cu, Fe and Zn concentrations were observed. LR3IGF-1 was infused continuously over 21 days into the skin of 6 sheep using a bilateral arterio-venous preparation. Another 6 sheep were infused in the same way with saline only (controls). Feed intakes were the same for both groups. Arterial blood samples were obtained prior to the start of treatment and at 1, 7, 14 and 21 days. Plasma samples were prepared and analysed for concentrations of endogenous IGF-1, insulin, cerulophasmin, macro-elements (Ca, Mg, Na, P and S) and the trace elements, Cu, Fe, Mn and Zn. Plasma concentrations of the macro-elements were unchanged over the treatment period and were not significantly different between the two groups. However there was a significant effect of treatment (P<0.001) and treatment x time interaction (P=0.024) on the Cu concentration in plasma. After 7 days the Cu concentration in plasma of the LR3IGF-1 group increased from 1.06}, issn = {1176-5283}, author = {Friend MA and Robards GE and Lindsay AR and Champion SC} } @conference {40724, title = {Reproductive performance of synchronised lactating dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {242-244}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The objective of this trial was to evaluate the reproductive performance of lactating dairy cows following oestrous synchronisation with a combination of progesterone, oestradiol and prostaglandin. Cycling cows in 11 herds were randomly divided, with restriction to age, calving date, condition score and breed, into synchronised (n=1332) groups. Those in the synchronised group were each treated with an EAZI-BREED}, issn = {1176-5283}, author = {Xu ZZ and Burton JR and Burton LJ and Macmillan KL} } @conference {40704, title = {Response of trace element concentrations in plasma of sheep to chronic infusion of a recombinant variant of IGF-1}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {179-182}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Bio-ijmpedance (BI) is the opposition of biological tissues to the flow of an alternating low electrical current. Tissue BI is quantitatively inversely related with tissue hydrational status. Several reproductive events of importance in the management of the cow are characterised by changes in fluid content and electrolyte concentration of the genital tissues; these changes can be detected and quantified by genital tissue BI monitoring. The objective of this presentation is to review existing and potential applications of monitoring genital tissue BI in cows as aids to cattle reproductive management. The main application is genital BI monitoring to determine the optimal insemination time. It is based on the fact that intravaginal and vulvar tissue BI decline ca 10-30\% during the peri-ovulatory stage of the ovarian cycle. Genital BI measurements can also be used to detect pending calving as well as post partum reproductive disorders: vulvar BI, measured with chronically implanted electrodes, declines ca 15 d before, and remains low until calving. During ca 40d post-calving, vulvar BI increases gradually and stabilises at about the time of resumption of ovarian luteal cyclicity. Intravaginal BI during the first 4-6 weeks post-calving is significantly lower in cows with reproductive disorders than in }, issn = {1176-5283}, author = {Lee J and Rounce JR and Hocking-Edwards JE and Harris PM} } @conference {40657, title = {The role of endogenous insulin-like growth factors-1 and -2 on lactation in rats}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {26-27}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Records were obtained for 1617 heifers in 26 herds using the Genermate}, issn = {1176-5283}, author = {Spencer GSG and Hodgkinson SC and Berry CJ} } @conference {40719, title = {Seasonal changes in LH profiles of ewes selected for and against an early lambing date}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {224-227}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Smith JF and Briggs RM and Parr J and Johnson DL and Duganzich DM} } @conference {40662, title = {Seasonal patterns of wool growth in Romney sheep selected for high and low staple tenacity}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {42-45}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Twenty Jersey and 12 Friesian cows were individually offered freshly cut pastures that had received either 100-150 kg nitrogen (N)/ha (HN) or 25 kg N/ha (LN) as urea, either ad lib. or restricted to 70\% of ad lib. Treatments were imposed for 2 consecutive 14-day periods during September and October 1993. Effects of N fertiliser on the chemical and botanical composition of pasture were minor. There were no significant effects of N fertiliser on mean fat corrected milk yield, (19.9 kg/day 4.0\% FCM), milk yield (16.2 kg/day), milk fat \% (5.6\%), milk fat yield (0.9 kg/day), or liveweight change (-0.59 kg/day). Milk protein yield (P.0.05) and protein \% (P<0.05) and protein \% (P0.01) were greater for LN than for HN treatment groups (0.58 vs 0.56 kg/cow/day and 3.6 vs 3.5\% respectively). Voluntary DMI was also affected by N fertiliser for cows on ad lib. pasture allowance (14.0 vs. 14.6 kg DM/cow/day for HN and LN treatments; P<0.01). The application of N fertiliser in winter/early spring, had only minor effects on pasture intake or milk yield and composition in early lactation. }, issn = {1176-5283}, author = {Woods JL and Bray AR and Rogers GR and Smith MC} } @conference {40734, title = {Selection for beef quality traits}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {275-277}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Records on 24 146 Angus and 5 632 Hereford carcasses processed at Manawatu Beef Packers between March 1993 and August 1994 which had been evaluated for beef marbling standard (BMS), beef fat standard (BFS) and beef colour standard (BCS) were used to derive overall meat quality score. Overall meat quality score in the Japanese grading system is determined by the lowest grade from: semi-objective assessment for BMS, BFS and BCS; and subjective assessment for meat brightness, firmness and texture, fat lustre and quality. Subjective measures of meat and fat quality are not routinely recorded at this plant and therefore overall meat quality score could only account for the three recorded items. The majority of Angus and Hereford carcasses (84.0 and 82.9\%) had an overall meat quality score of 1 (inferior) and no carcasses had score 5 (excellent). This study reports the effects of selection to improve Japanese overall meat quality score by single trait improvement of the three meat quality attributes. A change of one grade in BMS (or BFS) for Angus carcasses decreased the proportion of score 1 carcasses to 12.8\% (or 74.7\%) and improved overall meat quality score from an average of 1.17 to 1.96 (or 1.29). A change of one grade in BMS (or BFS) for Hereford carcasses decreased the proportion of score 1 carcasses to 16.1\% (or 66.8\%) and changed overall meat quality score from an average of 1.18 to 1.90 (or 1.35). Selection based on a well-designed progeny test would take 5 (or 9) years to improve BMS (or BFS) by one grade. Biological factors introduce a lag of at least six years from the start of test matings until there can be widespread harvest of beef animals with improved meat quality. Selection for BMS can improve overall meat quality score more effectively and more rapidly than selection for other meat quality traits. }, issn = {1176-5283}, author = {Charteris PL and Garrick DJ and Morris ST and Wright LA} } @conference {40714, title = {Sensitive PCR for detecting Benzimidazole resistant sub populations of ovine nematodes in the Waikato}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {209-210}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Lehrer S and Davey H and Watson T and Wilkins RJ} } @conference {40750, title = {Sheep farming - beyond survival}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {315-317}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {none supplied }, issn = {1176-5283}, author = {Campbell R} } @conference {40753, title = {Sires for more valuable lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {324-326}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Specialist terminal sire breeds offer several advantages to the commercial farmer, particularly their ability for rapid change in relevant traits in response to market signals. The production, survival and disease resistance benefits resulting from the hybrid vigour in the crossbred progeny have also widely documented. Terminal sires breeds also provide for efficient utilisation of between breed differences in carcass quality and mature weight. However, terminal sires are presently under utilised by the NZ sheep industry. In future this situation is expected to change. Long term trends suggest that carcasses will be paid for on the basis of weight of lean meat. In addition, terminal sire breeders are increasingly using performance recording systems allied with methods of estimating carcass composition, both of which have markedly improved in recent years. Terminal sire breeds are the logical method to distribute major genes affecting growth and carcass quality. The identification, characterisation and "packaging" of these genes will become increasingly routine. }, issn = {1176-5283}, author = {McEwan JC and Davis GH and Fennessy PF and Clarke JN} } @conference {40723, title = {Some effects of using progesterone and oestradiol benzoate to stimulate oestrus and ovulation in dairy cows with anovulatory anoestrus}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {239-241}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Anovulatory anoestrus (AA) is a major form of infertility in pasture- fed dairy cows in New Zealand and is most frequently treated by injecting equine chorionic gonadotrophin (eCF) after pre-treatment with progesterone (P4). The effectiveness of this treatment varies between herds. Injecting oestradiol benzoate (ODB) from 24 h to 48 h following PA4 and ODB priming can also induce oestrus and ovulation in AA cows. Two field trials compared responses in 572 cows with AA treated with P4 alone, P4 + eCG and P4 + ODB. The P4 was administered per vaginum for 5 or 7 days using a CIDR device. An injection of 1 mg ODB at 48 h after device removal in Trial 1 increased the insemination submission rate during the following 4 days from 55\% among cows treated with P4, or P4 + eCG to 75\%, and reduced the incidence of non-responding cows from 21\% to 3\%. In Trial 2, the comparable results to ODB treatments were 86\% inseminated and 3\% not responding. The increased submission rates were not due to the ODB producing oestrus without ovulation. Consequently, 42\% of anoestrous cows treated with ODB conceived during the first week of AB, 75\% conceived after 6 weeks of AB and only 5.5\% were finally not pregnant. Comparable figures for herdmates treated with P4 but not injected with ODB were 29\%, 66\% and 12\% respectively. Injecting a low dose of ODB from 24 to 48 h after P4 pre-treatment can be used to successfully treat AA in dairy cows. }, issn = {1176-5283}, author = {Macmillan KL and Taufa VK and Day AM and McDougall S} } @conference {40661, title = {Staple tenacity versus staple strength}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {39-41}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Six nutritional regimes were applied to 134 Friesian heifers to determine the effects of differential rearing on productive and reproductive performance. Cycling animals were identified at 11.5 and 15 months by measuring progesterone in consecutive weekly blood plasma samples. Heifers were synchronised using CIDR devices and artificially inseminated for two cycles, followed by six weeks of natural mating. At 11.5 months, 95\% of the high (268 kg LW), 65\% of the medium (242 kg LW), and 2\% of the low (186 kg LW) nutrition groups were cycling. At 15 months, all heifers in the four high groups were cycling compared to only 82\% of heifers in the two low groups was probably enhanced by the CIDR progesterone treatment stimulating puberty in non-cycling heifers. Friesian heifers should average 300 kg to ensure all animals are cycling normally prior to the start of mating. }, issn = {1176-5283}, author = {Scobie DR and Merrick NC and Bray AR} } @conference {40668, title = {Tail docked dairy cattle: fly induced behaviour and adrenal responsiveness to ACTH}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {61-63}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Romney crossbred lambs (n=711) sired by selected Southdown high fat (SD+), low fat (SD-) and Texel rams were grown from weaning to 14 months of age under high(H), medium (M) or low (L) nutrition. A random half of H and L groups were run with the L and H groups respectively from 8 months onwards. Samples of lambs were slaughtered at 3, 5, 8, 11 and 14 months of age. Whereas there were significant carcass weight differences between nutrition and were almost always fatter than the SD- and Texel lambs. All genotypes showed markedly reduced levels of fat development during the post-weaning and winter periods, with highest levels in spring. Eye muscle width was more nutritionally responsive than eye muscle depth and, in relation to carcass weight changes, was greatest in winter. }, issn = {1176-5283}, author = {Phipps AM and Matthews LR and Verkerk GA} } @conference {40684, title = {Ultrasonic scanning of lamb carcasses for non-destructive carcass quality measurements}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {111-113}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Compensatory growth in cattle has been regularly reviewed (Allden, 1970; O}, issn = {1176-5283}, author = {Binnie DB and Farmer RJ and Clarke JN} } @conference {40755, title = {Using genetic variation for greater profit}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {328-330}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Over 20 years ago, cooperative group breeding schemes screened large gene pools to establish ram breeding flocks. This process invariably exploited differences between animals within a breed and not differences between animals regardless of breed. This paper describes the establishment and operation of Landcorp Farming Limited{\textquoteright}s Lamb Supreme (LS) terminal sire breeding programme and presents results of a comparative slaughter trial for discussion. In 1989 and 1990 Landcorp screened a total of 3,685 ewe hoggets from 501,000 animals. The progeny from 3 years{\textquoteright} mattings of these screened- in ewes constituted the nucleus flock of the LS programme. The progeny of rams from this flock mated to commercial Romney ewes were compared with straightbred Romneys (R) in a slaughter trial in three slaughters from January to May 1994. At the three slaughter dates, LS lambs had heavier pre-slaughter liveweights and carcass weights than R lambs and were no fatter when adjusted to the same mean carcass weight. Net returns averaged more per LS cross lamb than per straightbred R lamb. }, issn = {1176-5283}, author = {Nicoll GB} } @conference {40666, title = {Wool growth responses in Drysdale and high and low staple tenacity Romney sheep to nutrient supplementation in autumn}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {54-57}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {With the increasing sensitivity towards the use of growth promoters in animal husbandry, the search is on for }, issn = {1176-5283}, author = {Bray AR and Merrick NC and Smith MC and Scobie DR} } @conference {40663, title = {Wool yellowing susceptibility: Heritability, genetic and phonotypic correlations with productive traits in Australian Merino, Corriedale and New Zealand Romney sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {55}, year = {1995}, month = {Jan}, pages = {45}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Forty-two identical twinsets were milked either once (ODM) or twice (TDM) daily and offered pasture and silage, either to appetite (H) or restricted to 50-60\% of this level (L) for the last 5 weeks of the 93/94 season. Pretreatment, uninfected cows produced 8.45+/-0.28 1 milk/d (mean +/- S.E) with a mean somatic cell count (SCC) of 37.1+/-3.3 x 10/3 cells/ml). Milk yields were significantly reduced (P<0.001) by L nutrition and by ODM. LogSCC was significantly increased (P<0.05) by L nutrition, due to reduced milk volumes but was not affected by ODM. Concentration of the serum-derived proteins, immunoglobulin G and bovine serum albumin, increased significantly for L nutrition and ODM. This suggests that involution had been accelerated in these animals, whose average daily milk yield was below 5 1/d. In late lactation milking should be discontinued for cows with milk yields of less than 5 1/d as involution may be initiated below this yield. }, issn = {1176-5283}, author = {Benavides MV and Young MY and Beatson PR and Maher AP and Reid TC} } @conference {40616, title = {Accounting for scale effects in genetic evaluation of dairy cattle.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {276-280}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Lactation records of dairy cows calving between 1986 and 1989 were obtained from the Livestock Improvement Corporation of the New Zealand Dairy Board. There were milkfat yields from 2,004,854 lactations in 83,805 contemporary groups. The data were divided into three equal-sized subsets based on average level of production (scale) in the contemporary group; these being (kg milkfat {\textpm} sd) High (H), 172 {\textpm} 28; Medium (M), 152 {\textpm} 26; and Low (L), 139 {\textpm} 25. The objectives of this study were to provide evidence of heterogenous variance and to identify the best of three methods to stabilise the variance of milkfat yields for use in the genetic evaluation of New Zealand dairy cattle based on a best linear unbiased prediction procedure using an across breeds animal model which will be implemented in July 1996. The methods investigated for the accounting of scaling were adjustment based on: contemporary group standard deviation (SD); contemporary group means (MEAN); and logarithmic transformation (LOG) of milkfat yield. The overall correlation between contemporary group means and standard deviations was 0.44. This value was reduced to 0.31 in SD-transformed data, -0.27 (MEAN) and -0.24 (LOG). Correlations between breeding values for sires estimated from the independent data sets using a mixed model but without adjustment for scale were 0.76, 0.73 and 0.78 in the L-M, L-H and M-H comparisons. These were lower than expected correlations of 0.85, 0.85 and 0.87, reflecting inaccuracies in sire evaluation when scaling is ignored. Calculated correlations were similar for SD and MEAN (0.78, 0.75 and 0.80; 0.78, 0.74 and 0.78), but LOG reduced the calculated correlations (0.73, 0.69 and 0.75). Results confirm the problem of scaling on genetic evaluation of New Zealand dairy cattle and indicate other methods need to be studies to correct the scaling problem. }, issn = {1176-5283}, author = {Lopez-Villalobos N and Garrick DJ and Harris BL and Blair HT} } @conference {40596, title = {Animal Production in eastern Turkey}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {189-192}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = { AB: Subsistence village livestock farmers in the eastern provinces farm approximately 30\% of the sheep and cattle of Turkey. Stock are housed for winter and grazed on communally owned and managed pastures for the remainder of the year. Typically farmers have 1 to 6 cows and 30 to 100 sheep or goats. A survey of 91 farmers showed that 55\% of the cattle were of the local Anatolian breed and 37\% were of exotic cross. Calving interval averaged 12.5 months, excluding the 10\% barren cows. Female progeny were retained as herd replacements, males were sold between 8 and 18 months old to specialist cattle finishers who feed cattle indoors and aim to make a US$50 to US$120 margin per beast in a 4 to 6 month period. Sale of surplus lambs and milk products are the main sources of income for sheep farmers. Flocks averaged 80\% to 100\% lambing with lamb mortality ranging between 5\% and 40\%, depending on the level of winter feeding. Technology exists in Turkey for the improvement of winter feeding, and intensive lamb finishing, but technology transfer is constrained lack of experienced staff and limited training in livestock production of extension staff. }, issn = {1176-5283}, author = {Thompson KF and Hart ND} } @conference {40549, title = {Anthelmintic resistance in the New Zealand Animal Production Industries}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {1-4}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Enzymeimmunoassays (EIAs) for oestradiol-17b and progesterone were developed using antibody-coated microtitre plates, and steroid-horseradish peroxidase conjugates as steroid {\textquoteright}tracers{\textquoteright}. The characteristics of standard curves and the precision of measurements were comparable between the EIAs and corresponding radioimmunoassays (RIAs). The applicability of the EIAs was demonstrated by using them to measure oestradiol-17b and progesterone concentrations in media sampled daily from cultures of bovine granulosa cells. The EIAs detected the characteristic switch in cellular steroidogenic capacity from oestradiol-17b to progesterone production typical of cultured granulosa cells. There was a significant linear correlation (P<0.001) between the EIAs and RIAs in the concentrations of steroids measured in granulosa cell culture medium by the two immunoassay formats. These findings may encourage other laboratories to consider converting "in-house" RIAs to EIAs, thereby eliminating the potential health and environmental hazards associated with the radioisotopes required for RIA. }, issn = {1176-5283}, author = {Watson TG} } @conference {40621, title = {Anti goat IGF binding protein 3 antibodies from chicken egg yolk}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {297-300}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The use of chickens for the production of highly specific antibodies to mammalian proteins offers a number of advantages over more conventional methods. Antibody responses to IGFBP-3 immunogen were apparent in the serum of chickens after only two inoculations with low levels of the immunogen. These specific antibodies subsequently appeared in the chicken egg yolk at levels of approximately 40\% of those estimated in serum. A simple, rapid and reproducible two step method for the extraction and purification of the immunoglobulin fraction from egg yolk using octanoic acid is described. Relatively large quantities of specific antibodies can be obtained by these procedures. Egg yolk antibodies generated in this study will be used to develop an ELISA for measuring levels of IGFBP-3 in plasma and other body fluids. This approach is designed to overcome some of the difficulties associated with the use of ligand blotting analysis to quantify IGFBPs. }, issn = {1176-5283}, author = {McLaren RD and Prosser CG} } @conference {40630, title = {Biological efficiency: How relevant is this concept to beef cows in a mixed livestock, seasonal pasture supply context?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {333-336}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Efficiency, defined as the ratio of output to input, can be calculated for any product, and for any of the resources employed to generate that particular product. "Weight of calf weaned per unit cow liveweight" is commonly used to measure biological efficiency in the beef cow herd, based partly on the assumption that feed intakes and hence costs are related to liveweight. A more direct measure, and the one used here, is "weight of carcass produced per unit of feed intake". The biological efficiency of the traditional beef breeding cow, determined in this manner, is low compared to that of other beef cow systems (e.g. twinning cows, once-bred heifers). This is primarily because of the relatively low reproductive rate in traditional cow herds and the high proportion of annual feed consumption used to maintain the breeding female and her replacements. A simple output/input ratio may not, however, be appropriate for the mixed sheep and cattle systems which are widely used in New Zealand. For these systems, where a competitive or complementary relationship may exist between enterprises, a more complex efficiency ratio that contains elements of the whole farm system is likely to be more appropriate. Furthermore, in a seasonal pasture production system, where the supply of feed is likely to limit production at certain times of the year, feed does not have fixed value. Feed costs therefore become an important component of the efficiency equation. Utilisation by other livestock of a scarce resource (e.g. winter feed) is also likely to have an influence on the economic efficiency of the system. For example, if biological efficiency is ignored then output (weight of calf weaned) may be increased simply by increasing cow size but with no consideration of the extra feed inputs necessary to maintain larger cows, or the pressure that additional feed requirements may place on other components of the system at particular times of the year. In this paper, the relevance of biological efficiency is explored by comparing both biological and economic efficiencies of four cattle systems - traditional beef cows, beef x dairy cows (with and without twinning) and once-bred heifers - alone and in mixed sheep and cattle policies. We conclude that biological efficiency is a relevant concept, primarily because its components (carcass weigh and feed consumed) are also important determinants of economic efficiency. However marked differences between systems in the value of the carcass produced and/or feed consumed can lead to a poor correlation between the efficiency ranking of systems by biological and economic criteria. }, issn = {1176-5283}, author = {Morris ST and Brookes IM and Parker WJ and McCutcheon SN} } @conference {40619, title = {Blood and urinary metabolites in cattle differing in susceptibility to bloat}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {289-292}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Blood samples from 159 animals of known susceptibility to bloat were analysed for a range of proteins, minerals, acid base status, hormones and enzymes. Urine samples from the cows and heifers were analysed for minerals and osmolality. Each animal was sampled once only in a fed state. An increase in bloat breeding value of one unit (increasing susceptibility) was significantly associated (P<0.05) with a decrease in liveweight of 28 ({\textpm}6) kg and increases in blood of 0.26 ({\textpm}0.07) U/1 pepsinogen, 0.33 ({\textpm}0.14) mmol/l urea, 29.5 ({\textpm}11.3) nmol/1 Se, 4.9 ({\textpm}1.2) mmol/l red blood cell K, 0.5 ({\textpm}0.2) g/l beta globulin, and 13.9 ({\textpm}6.1) pmol/l gastrin. The data suggest there may be some physiological or metabolic differences between high and low susceptible animals either arising during the selection and breeding programme or which contribute to the susceptibility mechanism. }, issn = {1176-5283}, author = {Carruthers VR and Morris CA} } @conference {40577, title = {Bovine growth hormone and its effects on the local production of prostacyclin I2 and mammary blood flow in dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {111-114}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Our objective was to test the hypothesis that bovine growth hormone (bGH) can induce the secretion of vasodilators by the bovine mammary gland. Three adult lactating cows were surgically implanted with catheters in the left costoabdominal artery, in the left subcutaneous abdominal vein (milk vein) and in a lymph duct afferent to the left supramammary lymph node. In addition, a transit time flow probe was implanted on the left pubic artery. Cows were injected s.c. with either saline or 25 mg of bGH according to a crossover design. Samples from arterial and venous blood and from lymph fluid were collected from 2 hours before to 16 hours after the injection. Mammary blood flow was recorded at each sampling. Injection of bGH induced a gradual increase in mammary blood flow in lactating cows while it remained constant after the saline injection. Venous concentrations of 6-keto-prostaglandin F1a, a stable metabolite of the vasodilator prostacyclin I2, were not affected by bGH injection. However, lymphatic concentrations of the prostacyclin I2 metabolite increased when cows were injected with bGH. The time course of the increase in plasma IGF-I concentration was similar to that of mammary blood flow and 6-keto-prostaglandin F1a. In conclusion, a local release of prostacyclin I2 may be responsible for the bGH-induced increase in mammary blood flow. IGF-I might mediate this effect of bGH. }, issn = {1176-5283}, author = {Lacasse P and Block E and Couture Y and Petitclerc D} } @conference {40556, title = {Cadmium accumulation in liver and kidney of sheep grazing ryegrass/white clover pastures}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {31-34}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Pastures growing on soils fertilised with phosphatic fertilisers accumulate cadmium (Cd) in their plant tops in proportion to substrate concentrations. Sheep grazing pastures absorb some of this Cd. To quantify the rate with which Cd is accumulated in sheep tissue, three replicated 0.4 ha blocks were fertilised with either 333 kg/ha of single superphosphate only (control) or amended with CdSO4 to give 274g Cd/ha (high-Cd), and set stocked with 10, three months old Romney wether lambs. Cadmium (Cd) concentrations were determined in liver, kidney, proximal duodenal and skeletal muscle tissue of sheep, ingesting either (means {\textpm} s.e.) 266{\textpm}22 (control) or 746{\textpm}58 (high-Cd) ug CD/day from three to six months or 290{\textpm}21 and 721{\textpm}72 ug Cd/day over six to eighteen months. Cadmium concentrations in kidney and liver tissue increased markedly over the first three months: 0.042{\textpm}0.006 to 0.32{\textpm}0.03 (Control) and 0.57{\textpm}0.04 (high-Cd) ug Cd/g fresh tissue, and 0.04{\textpm}0.006 to 0.12{\textpm}0.02 (Control) and 0.31{\textpm}0.06 (high-Cd) ug Cd/g fresh tissue, for kidney and liver respectively. Although total Cd content continued to increase, as organ size increased, over the next 12 months daily accumulation rates in both tissues were much lower compared with those over the first three months. For example, daily Cd accumulation in kidney decreased from 0.25{\textpm}0.002 to 0.06{\textpm}0.01 and 0.47{\textpm}0.04 to 0.32{\textpm}0.05 (ugCd/d) for sheep from the control and high-Cd pastures respectively. Total Cd content in kidney and liver combined accounted for approximately 0.25\% of total Cd ingested by sheep age three to six months but this significantly decreased to 0.1\% in sheep age six to eighteen months. At higher Cd intakes increased metallothionein protein synthesis in kidney and liver tissue enabled animals to be more efficient in sequestering Cd. This resulted in reduced accumulation of Cd in muscle tissue of sheep on the high- Cd pastures (2.0{\textpm}0.04 and 5.0{\textpm}0.08 ng Cd/g) compared with those grazing the control pasture (4.0{\textpm}0.6 and 14{\textpm}5 ng Cd/g) in animals from the first and second periods respectively. The results from this study show that it is the first few months after weaning that fastest uptake into kidney occurs and therefore strategies to reduce Cd absorption and subsequent accumulation, e.g. by increasing zinc in the diet, should focus on young animals. }, issn = {1176-5283}, author = {Lee J and Grace ND and Rounce JR} } @conference {40598, title = {Carcass, liver and kidney characteristics of lambs grazing plantain (Plantago lanceolata), chicory (Cichorium intybus), white clover}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {197-200}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Plaintain (Plantago lanceolata L.) is being evaluated in New Zealand as a potential pasture species because of its supposed medicinal attributes. Seventy six, four month old Coopworth ram lambs were rotationally grazed on either plantain (PL), chicory (Cichorium intybus L.; CH), white clover (Trifolium repens L.; WC) or perennial ryegrass (Lolium perenne L.; RG) for 82 days from January to April, 1993 at an allowance averaging 1.8 kg green DM/lamb/day. At slaughter treatment differences in carcass weight were apparent (16.8, 18.3, 20.1 and 15.6kg, respectively, for PL, CH, WC and RG). After adjustment for body size no differences in carcass characteristics were apparent between treatments. However, differences still existed for liver and kidney size. WC lambs were the heaviest at slaughter and had the largest livers after adjustment. In contrast, kidney size did not follow liveweight with PL lambs having the largest kidneys after adjustment. Serum urea and creatinine levels indicate that renal function was not impaired in PL lambs relative to RG lambs. }, issn = {1176-5283}, author = {Deaker JM and Young MJ and Fraser TJ and Rowarth JS} } @conference {40622, title = {Characterization and regulation of cationic amino acid transport in bovine mammary epithelial cells - Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {301-302}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied }, issn = {1176-5283}, author = {Kiaei M and Prosser CG and Grigor MR} } @conference {40593, title = {Chiapas sheep - wool production and animal health in a unique sheep breed}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {177-180}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {In the Highlands of Chiapas, in southern Mexico, over 10,000 Indian families from the Tzotzil-speaking group manage small flocks of Chiapas sheep, a unique local breed. Sheep flocks are managed by the Indian women with all animal health care based on traditional herbal remedies. The University of Chiapas (UNACH) is conducting a research programme to investigate the biological basis of traditional sheep husbandry systems and to improve wool production. Animal health research tested the effectiveness of some common herbal remedies. In 4 sheep flocks, garlic (Allium sativum) and Mexican tea epazote (Chenopodium ambrosioides) were administered orally either separately or together. The most effective treatment was the combined 5g garlic + 5g epazote, which significantly reduced (P<0.01) the number of eggs of gastrointestinal nematodes by 66 {\textpm} 8\% and 61 {\textpm} 28\% at 1 and 2 weeks after treatment. Reductions in Eimeria spp. oocysts by 43\% in 2 different treatments (5g garlic at 3 weeks post-treatment and 5g garlic + 5g epazote at 2 weeks post- treatment) were just below the accepted 50\% effectiveness level. These preliminary results have clarified the need for controlled research trials, testing dose rate and frequency of these herbal treatments. Three colour phenotypes of Chiapas sheep have been identified: W-white, BL- black and BR-brown. Wool is subjectively graded by shepherdesses as good (G), medium (M) or poor (P) and 12 month fleece weights show differences between the wool grades - mean annual fleece weight (kg) was higher (P<0.01) for G (1.38{\textpm}0.10) than P (0.95{\textpm}0.10) with M intermediate (1.11{\textpm}0.10). Twenty-seven sheep were examined with the aim of determining which objective fibre characteristics were used in the subjective assessment of wool grade. Mean fibre diameter was coarse (35.7 microns) and did not differ between wool grade or colour phenotype. Staple length differences (mm) were highly significant (P<0.001) between G, M and P (97.3 vs 77.6 vs 63.4) but not colour phenotypes. Kemp levels (\%) were higher (P<0.001) for BL (10.24{\textpm}1.4) vs W (2.32{\textpm}1.4) and BR (2.19{\textpm}1.4); and \% medullation for BL was 12.14 (P<0.02) compared to 5.19 and 2.77{\textpm}1.87 for W and BR respectively. These results show that the most consistent fibre characteristic distinguishing the different wool grades is staple length of the long fibres, which could be related to differences in seasonal fleece growing patterns. The results for fibre characteristics differences between colour phenotypes has helped to objectively characterise these phenotypes and provided a valuable insight into the general fibre characteristics of Chiapas sheep. }, issn = {1176-5283}, author = {Perezgrovas R and Parry A and Peralta M and Zaragoza L and Trow D and Pedraza P} } @conference {40565, title = {Comparative performance of Angus cattle and swamp buffalo fed ad libitum either a lucerne hay and concentrate ration or pasture hay.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {67-70}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Voluntary intake and liveweight gain of Angus cattle (CAP) and swamp buffalo (B) were compared on 2 feeds; ad lib., lucerne hay (L) + 1 kg concentrate/animal/day (LC) and ad lib. pasture hay (P) in a 2 x 2 Latin square designed trial. The two hays had similar ME values; L, 8.5 and P 8.7 MJ/ME/kg DM, but differed (P<0.05) in protein content; L, 14.6\% and P 10.1\%. The concentrate was 13.5 MJ ME/kg DM and 14.1\% protein. Animals were fed in a feed-lot with individual pens/treatment. Intake was assessed on a group basis for all treatments and individual animal intake was assessed for the P treatments only using slow release chromium capsules. Two, 4 week experimental periods were preceded by a 2 week feed adjustment period. Liveweight gains showed a species x fed interaction (P<0.001) with individual treatment gains (kg/day) of; 0.80, -0.54, -0.02, -0.09 for CLC, CP, BLC, and BP groups respectively. Cattle consumed (group assessment) more (P<0.05) L Hay than buffalo; 127 vs 99 g DM/kg LWT0.75. The intake of P hay was similar for each species; 102 and 100 g DM/kg LWT0.75 for C and B respectively. The release of CR2O3 from the capsules were similar for the two species (1.56 g/day). Intakes of P hay assessed by the marker techniques differed (P<0.05); 100 and 88 g DM/kg LWT0.75 for the CP and BP treatments respectively. The difference in performance of the two species on P may have been the result of the marginal (for cattle) protein levels. No explanation is given for the poor performance of buffalo on the LC ration. }, issn = {1176-5283}, author = {Thomson NA and Death AF and Power MT} } @conference {40588, title = {Comparison of methods for measuring fibre diameter of Romney Wool}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {155-158}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Wool from lines of Romney sheep selected on the basis of staple strength was measured for mean fibre diameter using both the airflow apparatus and an Optical Fibre Diameter Analyser (OFDA). For wool from "low strength" and "control" selection lines, airflow measurements tended to be upwardly biased in relation to the OFDA measurements, while for wool from the "high strength" line the airflow measurements tended to be downwardly biased. Two sources of bias are known in the literature, medullation and standard deviation. In this work the latter seemed to be more important, which may be a consequence of the relatively low level of medullation present in these wools (8.6\%). For research work the OFDA is put forward as the preferred instrument. }, issn = {1176-5283}, author = {Scobie DR and Merrick NC and Saville DJ} } @conference {40601, title = {A comparison of the carcass and meat quality of Awassi-cross and Texel-cross ram lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {209-214}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The Awassi is a fat-tailed sheep breed from the Middle East that has recently been imported into New Zealand for live-sheep export and for milk production. The aim of the current trial was to compare the carcass and meat quality of Awassi-cross and Texel-cross ram lambs. There were 36 lambs in each sire-breed group with an equal number from Romney and Poll Dorset ewes. Lambs were allocated at random within breed-cross groups to groups of 9 that were slaughtered in either May or August to give an overall mean carcass weight of 19.7kg. The Awassi-sired group had a lower dressing-out percent (44.4 vs 44.8; P<0.01), similar GR tissue depths (7.6 vs 8.4 mm) but more weight-adjusted leg fat (537 vs 446g. P<0.001). The most clear-cut difference was in carcass shape with Awassi-cross lambs having longer carcasses (1068 vs 1013 mm), longer legs, and longer, heavier leg bones at a constant carcass weight (all P<0.001). The shape difference at a common carcass weight was also reflected in the Awassi-cross lambs having lower leg muscle to bone ratios (3.49 vs 3.88), muscle weight (2047 vs 2172 g), and muscularity values (0.436 vs 0.488) than the Texel-cross lambs, and shallower longissimus muscle depths (28.0 vs 29.8 mm)(all P<0.01). Differences between Awassi and Texel-sired lambs in tenderness (shear values) and colour (L*,a*,B* values) of the semimembranosus muscle were not significant. Differences between dam-breed groups were generally small, although, relative to the Poll Dorset, the Romney-cross group had lower weight-adjusted longissimus depths (28.2 vs 29.6 mm) and leg muscle to bone ratios (3.57 vs 3.80(both P<0.01). When adjusted to the same carcass weight, lambs slaughtered in August had lower dressing-out percentages (42.6 vs 46.6), lower GR depths (6.7 vs 9.3 mm, longer carcasses (1063 vs 1018 mm), and poorer leg muscularity (0.450 vs 0.474) than those slaughtered in May (all P<0.02). In this study Awassi-cross carcasses were inferior to those of Texel-cross lambs in terms of composition and shape, but differences in meat quality not apparent. }, issn = {1176-5283}, author = {Holloway IJ and Purchas RW and Power MT and Thomson NA} } @conference {40628, title = {The complementary contribution of the beef cow to other livestock enterprises}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {323-328}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {This paper reviews potential benefits of beef cows to other livestock enterprises on a sheep and beef farm. These benefits may include general benefits of cattle such as improved sheep performance via improved pasture quality. They may also include benefits specific to cows such as the efficient use of low quality feed and feed demand patterns which match pasture production. A linear programming model is used to quantify complementary benefits of breeding cows to the total farm economy. This is done by comparing the profit from finishing only policies with those that include breeding cow and finishing cattle policies. When the marginal benefit in farm profit is all attributed to the breeding cows their worth is between 5 and 26\% greater than estimated by an enterprise analysis which does not account for complementarity. However, complementary benefits cease when returns from finishing reach $16/su greater than cows. Field system trials are required to validate these conclusions. }, issn = {1176-5283}, author = {McCall DG} } @conference {40632, title = {Current and emerging reproductive technologies for beef breeding cows.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {345-350}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Reproductive technologies may be defined as any technology which impacts on the reproductive potential of the herd. Reproductive technologies applicable to beef breeding cows can broadly be classified into those requiring either a low, medium or high technical input. The examples of {\textquoteright}Low Technology{\textquoteright} options discussed are: age at first joining, breed/cross or strain of cow, time of calving, and pregnancy diagnosis. In traditional breeding cow herds, cow productivity can be increased by modest amounts (5-10\%) if only single-option {\textquoteright}low tech{\textquoteright} changes are implemented. However, these fundamental technologies need to be well developed before higher technologies can be successfully applied. Two examples of {\textquoteright}Medium Technology{\textquoteright} strategies that have been available for some time include oestrous synchronisation and multiple suckling. Oestrous synchronisation has the potential to facilitate an increase in the number of herds adopting yearling heifer mating. Twin suckling through fostering an additional calf has been demonstrated to significantly increase the number of calves weaned per cow. Emerging {\textquoteright}High Technology{\textquoteright} options include: twinning, controlling the sex of calves at conception and cloning. Future developments in embryo technologies are vital in many of the emerging reproductive technologies for beef cows. }, issn = {1176-5283}, author = {McMillan WH} } @conference {40625, title = {The current status of the beef breeding cow in New Zealand mixed livestock production systems.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {311-314}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The total beef breeding cow herd in New Zealand, currently numbers 1.45 million head. Of the total beef herd, breeding cows make up only 30\%. In 1975 when numbers peaked at 2.31 million, breeding cows made up 37\% of the total beef herd. Despite the decline in the New Zealand breeding cow herd, beef production now exceeds 1975 levels. Per head carcass weights have increased and there is an increasing contribution of beef cattle from the dairy industry. Pastoral land loses to forestry are expected to exceed 500,000 ha in the next decade, much of this from areas grazed by breeding cows. The beef breeding cow is complementary to the performance of other stock classes. Her seasonal feed demand profile, her ability to utilise surplus often low quality feed, buffer herself against periods of low feeding and to be a source of equity and income stabilisation is highly regarded by farmers. Compared to a traditional self replacing beef breed herd, a dairy beef cross breed herd where all replacements are sourced from the dairy industry will return up to 43\% more revenue per hectare. With the development of new technology there is growing potential for the beef breeding cow to compete at all levels of the beef production line. }, issn = {1176-5283}, author = {Webby RW and Thomson RD} } @conference {40634, title = {Determining the number of calves in early pregnancy using real-time ultrasound imaging in beef cows induced to twin.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {353-356}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Details of the timing of pregnancy loss following induced twinning are unknown. The aim of this study was to evaluate real-time ultrasound as a method of determining early pregnancy status (0, 1 or 2 foetuses) in beef cows induced to twin using AI and ET. A 7.5 Mhz ultrasound probe was used intra- rectally to count foetuses in 2 experiments. In Exp. 1, 57 heifers were examined between 25 and 60 days of pregnancy and then slaughtered. In Exp. 2, up to 103 cows were examined between Day 25 \& 60 of pregnancy, and final pregnancy status was confirmed using calving records. In Exp. 1, the accuracy of Day 25, Day 45 and Day 60 predictions of 2 foetuses was 100\%, 20\% and 100\%, and 1/24, 5/33 and 1/33 twin pregnant heifers were predicted. The accuracy of correctly predicting twin outcomes was 33, 50 and 33\% at the same 3 stages of pregnancy, but only 3, 2 and 3 twin pregnancies occurred, respectively. In Exp. 2, there was generally little difference between the accuracy of predicting twin pregnancies and the accuracy of the prediction. Thus, at Day 25, 35 and 45 and 60, the accuracies were approximately 20, 47, 52 and 45\%. Twenty recipients eventually calved twins. We conclude that real-time ultrasound imaging up to Day 60 is not an accurate technique for determining twin pregnancy status of cows. Loss of concepti between scanning and term did contribute substantially to this poor result in Exp. 2, but not in Exp. 1. }, issn = {1176-5283}, author = {McMillan WH and Oakley AP and Hall DRH} } @conference {40571, title = {The effect of block and paddock grazing in winter on cow behaviour, cow performance and herbage accumulation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {91-94}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Two management methods for wintering dry cows on pasture (block and paddock) were compared at the Taranaki Agricultural Research Station over a 45 day period. Treatment effects on aggressive behaviour, grazing behaviour and liveweight gain were measured in addition to effects on pasture treading damage and subsequent herbage accumulation. The block grazed group had an area of 25 m2/cow/day, and were confined to a new area (0.1 ha) of pasture each day. The paddock grazed group had an area of 125 m2/cow/day, grazing the total paddock area (0.5 ha) over five days. There were 32 cows and 8 heifers in each treatment group. Agonistic activity in the paddock group was 50\% lower in week one and 28\% lower in week six, than the block group. Paddock cows and heifers gained more liveweight (p<0.01) than block cows and heifers; 0.22 and 0.24 kg/animal/day more respectively. Herbage accumulation over the subsequent three months (July - September) was 290 kg DM/ha lower (p<0.05) on the paddock grazed areas compared to block grazed areas. Paddock grazing reduced agonistic activity among heifers and cows and gave higher liveweight gains. Some of this advantage could possibly be negated by lower herbage accumulation in the subsequent three months. }, issn = {1176-5283}, author = {Judd TG and Thomson NA and Barnes ML} } @conference {40579, title = {Effect of breed on plasma carotene concentration in New Zealand dairy heifers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {119-120}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Factors affecting plasma carotene concentration were investigated in New Zealand dairy heifers. Blood samples were collected from 4000 dairy heifers in spring in November 1992. Significant (P<0.001) variation was found in plasma carotene concentrations due to region, breed and farm. Values for individual cows ranged from 1.7 to 56.2 ug/ml. Purebred Jersey heifers had the highest plasma carotene levels (18.2 {\textpm} 0.4 ug/ml), purebred Friesians the lowest (14.4 {\textpm} 0.2 ug/ml), crossbreds were intermediate with 50\% Jersey and 50\% Friesian significantly different from the purebreds (16.9 {\textpm} 0.6 and 15.4 {\textpm} 0.4 ug/ml respectively). }, issn = {1176-5283}, author = {Newman S-AN and Knight TW and O{\textquoteright}Neill KT and Death AF and Ridland M} } @conference {40568, title = {Effect of contrasting spring grazing management on summer-autumn pasture and milk production of mixed ryegrass-clover dairy swards.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {79-82}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Research at Massey University has shown that a spring grazing management laxer than the conventional intensive grazing allowing some early ryegrass seedhead development before close grazing at anthesis ("Late Control") may result in improved summer-autumn pasture production. Comparisons between conventional and late control spring grazing managements for dairy cows were carried out, on a paddock scale, during 1992/93. Late control swards showed enhanced dry matter production before (24.5\% increase - P<0.05) and after (32.0\% increase - P<0.10) the control grazing in early December. Concomitant measurements of animal performance revealed that the increased pasture production during the summer-autumn period could be effectively converted into milk by dairy cows, and resulted in an increase in milk-solids production of about 10\% per cow (P<0.10). The implications of these results to dairy management systems are discussed in the context of pasture responses to spring management and alternative conservation strategies. }, issn = {1176-5283}, author = {Da Silva SC and Hodgson J and Matthews PNP and Matthew C and Holmes CW} } @conference {40570, title = {The effect of different perennial ryegrass cultivars on dairy animal performance}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {87-90}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A study at the Taranaki Agricultural Research Station investigated possible limitations to dairy production due to recently released ryegrass cultivars. Dairy animals grazed pure swards of either Yatsyn-1, Embassy, Vedette or Pacific in a series of three trials from February 1992 to April 1993. Three ryegrass cultivars (Yatsyn-1, Embassy and Vedette) were infected with the endophyte Acremonium lolii. Pacific was infected with an Acremonium endophyte, strain 187B. In trial 1 (autumn 1992) liveweight gain of dairy calves grazing the respective cultivars over eleven weeks were monitored. Trial 2 (spring 1992) and trial 3 (summer/autumn 1993) were each conducted over 3 consecutive 8 day periods using dairy cows. Liveweight gain and ryegrass staggers were monitored in trial 1, and milk volume and composition in trials 2 \& 3. Herbage mass before and after grazing, dry matter disappearance, botanical composition, lolitrem b, in-vitro digestibility and crude protein levels were measured on each occasion, and ergovaline levels in trial 3. Ryegrass cultivar had no effect on calf liveweight gain. Ryegrass staggers were encountered in calves grazing Yatsyn-1, Embassy and Vedette but not in Pacific. In spring and in February and March of the summer/autumn trials, ryegrass cultivar had no effect on milk production or composition. Milksolids production from Yatsyn-1 was lower (P<0.05) than from Vedette and Pacific in April. Lolitrem content of Pacific was lower (0.14 ug/g grass) and ergovaline content higher (0.99 ug/g grass) in comparison to the other ryegrasses. There was no difference between cultivars in pasture utilisation, botanical composition, digestibility or crude protein levels. It is concluded that ryegrass cultivar or endophyte strain had little effect on dairy animal performance. }, issn = {1176-5283}, author = {McCallum DA and Thomson NA} } @conference {40586, title = {Effect of level of nutrition and season on fibre growth in alpacas}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {147-150}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The effect of nutrition on fibre production varies with species and response to nutrition may also be influenced by season. This study examined the effect of feed allowance and season on fibre growth in alpacas. 14 one- year-old alpacas were pen-fed a pelleted lucerne diet at a maintenance or ad lib intake level for 11 weeks in summer (January - February) and winter (July - September). Intake, liveweight gain and fibre growth rate were measured. Voluntary feed intake was 45\% higher in summer than in winter, 68 vs 47 {\textpm} 2 g DM/kg0.75/day. Estimated maintenance requirements from this trial were 31.11 g DM/kg0.75/day or 0.276 MJ ME/kg0.75/day. There was a positive relationship between feed intake, liveweight gain and fibre growth rate. Increased feed allowance resulted in higher liveweight gain and increased fibre growth rate. Differences in fibre length growth between maintenance and ad lib feeding levels, 0.36 and 0.33 {\textpm} 0.02 mm/day respectively, were not significant (P=0.07). Feeding level had no effect on fibre diameter. Fibre growth rate was greater (0.77 vs 0.62 {\textpm} 0.04 mg/cm2/day) and fibre diameter coarser (33.7 vs 31.3 {\textpm} 0.9 {\textmu}) in summer than winter. The rate of response of fibre growth to increased feed allowance was the same in summer and winter. }, issn = {1176-5283}, author = {Newman S-AN and Paterson DJ} } @conference {40583, title = {The effect of long-day photoperiod treatments on plasma prolactin and wool follicle activity in New Zealand Wiltshire sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {135-138}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Exposure of NZ Wiltshire sheep to a long-day photoperiod during late winter/spring has previously been shown to alter wool follicle growth patterns. The present experiment was undertaken to evaluate the plasma prolactin and wool follicle response to treatment with either 1, 2 or 3 months of long days. Four groups of six, NZ Wiltshire ewes were subjected to long-day photoperiod (16L:8D) for 1 month (LD1), 2 months (LD2), 3 months (LD3) or natural photoperiod (control), commencing on the 3 August, after which they were released from light treatment into natural (indoor) spring daylength. Weekly jugular blood samples were assayed for prolactin (PRL) and skin biopsies were histologically assessed for wool follicle activity. Circulating PRL concentrations were low in all treated and control sheep at the start of the experiment (19 {\textpm} 2 ng/ml). In treated sheep mean PRL concentration increased (P<0.05) above control levels (8 {\textpm} 1 ng/ml) within 1 week after exposure to long days (52 {\textpm} 4, 51 {\textpm} 5 and 55 {\textpm} 2 ng/ml for LD1, LD2 and LD3, respectively). PRL concentrations remained significantly higher than controls (P<0.05) for the duration of each treatment reaching maxima of 148 {\textpm} 27 ng/ml, 180 {\textpm} 43 ng/ml, and 199 {\textpm} 33 ng/ml for LD1, LD2 and LD3 respectively. In LD2 and LD3 treatments, PRL concentrations declined to control levels by 3 and 2 weeks after treatment had ceased, respectively, but in the LD1 treatment PRL remained significantly above (P<0.05) control levels until between 2 and 3 months after treatment. Primary follicle activity (PFA) decreased in response to long-day treatment (P<0.01) reaching minima of 47 {\textpm} 9\%, 36 {\textpm} 6\%, and 33 {\textpm} 11\% in LD1, LD2, LD3 sheep, respectively. Secondary follicle activity (SFA) responses were most marked in the LD2 and LD3 treatments where they fell below (P<0.05) control levels reaching minima at 2 months into treatment (66 {\textpm} 15\% and 58 {\textpm} 13\% for LD2 and LD3, respectively). Both PFA and SFA increased to over 90\%, within 1 month after release into natural light, in all treatments groups (except PFA for the LD1 group which took 2 months after release to reach over 90\%). In support of previously reported trials an increasing level of plasma PRL was followed by a decline in follicle activity. The optimal time frame to achieve an effective synchronised follicle regression was between 2 and 3 months of long- day treatment. The long-day treatment system produced a complete follicle growth cycle in temporal synchrony and is therefore a potential model for the investigation of structural and biochemical processes surrounding transitions between active and resting stages of fibre growth. }, issn = {1176-5283}, author = {Craven AJ and Parry AL and Wildermoth JE and Pearson AJ} } @conference {40585, title = {The effect of manipulation of plasma prolactin concentration on cashmere growth in spring}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {143-146}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Domperidone was administered to cashmere goats at 2.5 mg/day either by a daily subcutaneous injection at 1000 hours (INJ, n=6) or by a subcutaneously fitted osmotic minipump (OSP, n=6). There was an untreated control group (C, n=5). The treatments commenced on 13 September 1991 and continued for 14 days. Daily plasma prolactin concentrations at 1200 hours measured across the 14 days of treatment were 612{\textpm}32, 73{\textpm}35, and 60{\textpm}34 ng/ml in INJ, OSP and C groups respectively (P<0.001), while daily plasma PRL concentrations at 1000 hours, immediately prior to the injection, were 33{\textpm}6, 72{\textpm}7 and 60{\textpm}8 ng/ml in INJ, OSP and C groups respectively (P<0.01). Mean downlength was lower in INJ goats (34{\textpm}4mm) than OSP goats (51{\textpm}4mm) and C goats (46{\textpm}4mm). A greater percentage of fleece by weight was shed earlier (P<0.05) in INJ compared to the C group. Primary follicle activity also increased earlier (P<0.001) in INJ goats when compared to C and OSP goats. There was no effect of OSP on fibre growth and no overall effect of INJ on guard hair length, shedding score, presence of newly erupted cashmere fibres, and secondary follicle activity. In conclusion, DOM administered at 2.5 mg/day for 14 days by injection, but not by osmotic pump, perturbed fibre growth in primary and not secondary follicles. }, issn = {1176-5283}, author = {Litherland AJ and O{\textquoteright}Neill KT} } @conference {40592, title = {Effect of nutrition on fine wool production in Merino wethers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {173-176}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The potential to reduce fibre diameter of wool from Merino sheep using feeds that are readily available and cheaply produced in New Zealand was investigated. Two hundred and twenty fine wool two year old and mature Merino wethers were allocated to four feeding treatments for 12 months. The four feeding treatments were 1) silage, 2) silage and grass, 3) grass allocated three times per week, and 4) grass allocated once per week. Monthly liveweight, wool growth rate and fibre characteristics were measured. At the trial conclusion annual fleece production was determined and wool samples from each treatment group combined for line analysis. Liveweights fluctuated over the trial period indicating the difficulty of controlling feed intake accurately under pasture conditions. Wethers on the silage treatment had significantly lower fleece weights (2.4 kg) and finer fibre diameter (17.0 {\textpm} 0.2 and 17.6 {\textpm} 0.3 m for 2 year old and mature wethers respectively) than other treatments (3.2 kg, 17.6 {\textpm} 0.2 and 18.6 {\textpm} 0.3 {\textmu} for 2 year old and mature wethers respectively). Staple strength ranged from 17 to 36 N/ktex, with weakest wool from the silage treatments. Bulk values were low, ranging from 24.0 to 27.3 cm3/g. Wool was processed by a Japanese company for super high grade men{\textquoteright}s clothing fabric. The treatment groups were processed separately and evaluated at all stages from greasy wool to fabric. Little difference was found between the treatments except for the wool from the young silage treatment which had a superior fabric handle but was inferior at other processing stages. }, issn = {1176-5283}, author = {Newman S-AN and Paterson DJ and Haack NA} } @conference {40574, title = {Effect of once daily milking and concurrent somatotropin (bST) on production and mammary tight junction permeability in cows - Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {101-102}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied }, issn = {1176-5283}, author = {Stelwagen K and Davis SR and Farr VC} } @conference {40567, title = {The effect of pasture height on herbage intake and ewe production under continuous stocking management during the autumn.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {75-78}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A replicated trial design with ewes continuously stocked on mixed ryegrass/white clover pastures at three target sward surface heights (SSH) of 4, 6 and 8 cm, and 16 ewes per sward treatment (total 96 ewes), was carried out from February through to April 1993. Herbage intake was assessed indirectly from faecal output measured using chromium controlled release capsules and the in vitro digestibility of herbage samples obtained from oesophageal- fistulated sheep run with the ewes. Intake measurements were taken before and after the rams were joined with the ewes. Pasture measurements for the 4, 6 and 8 cm SSH treatments were: SSH, 4.12 vs 6.18 vs 7.97 cm (PSE 0.54 cm, P<0.05); mass, 3358 vs 4291 vs 5231 kg DM/ha (PSE 389 kg DM/ha, P<0.1); dead mater content, 38.9 vs 26.7 vs 40.4\% (PSE 5.8\%, NS); and organic matter digestibility, 68.0 vs 71.9 vs 63.8\% (PSE 1.21\%, P<0.0001). Organic Matter (OM) intakes fro the 4, 6 and 8 cm SSH treatments were 1.39 vs 1.86 vs 1.06 kg OM/ewe/day (PSE 0.08 kg OM/ewe/day, P<0.05) for the pre-mating intake and 1.26 vs 1.34 vs. 1.09 kg OM/head/day (PSE 0.06 kg OM/ewe/day, NS) for the mating intake period. Production responses of the ewes for the 4, 6 and 8 cm SSH treatments were: liveweight gain, 72 vs 83 vs. 73 g/day (PSE 5 g/day, NS); and wool growth rate, 1.37 vs 1.44 vs 1.42 mg/cm2/day (PSE 0.03 mg/cm2/day, NS). These results suggest that, in the autumn, maximum herbage intake and ewe performance on ryegrass - white clover pastures can be obtained at a sward height of about 4 cm, and that pasture digestibility and dead matter content in the pastures are the major limiting factors at this time of year. }, issn = {1176-5283}, author = {Burnham DL and Parker WJ and Morris ST} } @conference {40578, title = {The effect of peripartum administration of ovine prolactin on lactogenesis in autumn-lambing ewes.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {115-118}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Two routes of oPRL supplementation were used to elevate peripheral or local concentrations of PRL in autumn-lambing ewes which, based on previous results, were expected to have low plasma PRL concentrations and milk yields relative to spring-lambing ewes. Administration of 10 mg oPRL directly into the gland or subcutaneous injection of 0.5 mg/kg oPRL did not increase the milk yields, or change the composition of milk, compared to controls. These results suggest that the circulating and intramammary concentrations of PRL in autumn-lambing ewes are not limiting lactogenesis. However, because the plasma prolactin concentration in the ewes was unexpectedly high, it was not possible to reach firm conclusions regarding possible effects of supplementary oPRL in ewes with naturally low plasma PRL concentrations. Nevertheless, the results indicate that raising the intramammary concentration of PRL around the time of parturition, in ewes with circulating PRL concentrations characteristic of normal spring-lambing ewes, does not enhance lactogenesis. }, issn = {1176-5283}, author = {Peterson SW and MacKenzie DDS and McCutcheon SN and Lapwood KR} } @conference {40609, title = {Effect of selection for greasy fleece weight on the components of fleece weight in New Zealand Romney sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {243-246}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Variation in the clean fleece weight (W) between ewe hoggets born in 1988 from the Massey University fleece weight selected (FW) and control (C) flocks was related to variation in four components: predicted skin surface area (S), mean number of fibres (follicles) per unit area of skin (N), mean fibre cross-sectional area (A) and mean staple length (L). Mean W ({\textpm}pse) was 3.34 and 2.48 {\textpm} 0.07 kg for the FW and C lines, respectively. Of the components, L (147 and 126 {\textpm} 3.1 mm; P<0.001), N (29.6 and 27.0 {\textpm} 0.83 fibres/mm2; P<0.05) and A (1096 and 1002 {\textpm} 28.0 {\textmu}m2; P<0.05) were significantly greater in the FW line (n=27) when compared to the C line (n=22). The difference in W between the two lines was apportioned into contributions from the various components using the percentage deviation technique. The influence of combined components, wool weight per unit area (N x A x L), fibre volume (A x L) and total number of fibres (S x N) on W was also examined. The most important contributor to the difference in W between lines was L with A and N being less important; the contribution of S was relatively small. Wool weight per unit area had far more influence on between line differences in W than wool growing surface area (S) and fibre volume was more important than the total fibre number. Attempts were also made to assess the relative importance of the components of fleece weight between sheep within each line. The standardised partial regression coefficients of log transformed values of each component on W were; for the selected line, L = 0.26, A = 0.36, N = 0.16, S = 0.38; for the control line, L = 0.08, A = 0.58, N = 0.45, S = 0.53. High values of S relative to the other components of W suggest that the size of animal is more important in determining the phenotypic differences in fleece weight within the line than the genetic differences between lines. }, issn = {1176-5283}, author = {Liu AH and Wickham GA and Blair HT} } @conference {40584, title = {The effect of whole body cysteine supplementation on cysteine utilization by the skin of a well-fed sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {139-142}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Research, in both New Zealand and Australia, is being directed towards enhancing the sulphur amino acid supply of sheep by either plant or animal modification. This study investigated the effects of such improved systeine supply in well-fed sheep on both whole body and skin metabolism of cysteine.. The level of cysteine supplementation chosen (2g/d) represented about a 50\% increase in absorbed cysteine. Cysteine was supplied by jugular infusion to avoid loss during gut absorption. At this level of cysteine supplementation a preliminary trial on sheep fed either 700 g or 1250 g lucerne chaff showed no significant effect on wool production but a significant increase in wool sulfur (S) concentration over a one month period of treatment. In a second trial, two groups of five, 40kg, cryptorchid Romney sheep were offered 1200 g/d of lucerne chaff and one group was supplemented with 2g/d cysteine for five days prior to measurement, with the other group receiving saline only. Cysteine supplementation increased whole body cysteine utilization (irreversible loss of 35S-cysteine) from 4.7 {\textpm} 0.4 to 6.4 {\textpm} 0.3 g/d, while appearance of 35S-cysteine in the oxidation pool increased by 37\%. Cysteine supplementation resulted in an increase in circulating cysteine concentration (33.8 {\textpm} 5.6 to 51.1 {\textpm} 12.0 {\textmu}M) but blood flow to the skin patch (measured by dye dilution) was reduced from 0.29 {\textpm} 0.03 to 0.21 {\textpm} 0.02ml. min-1.g-1 skin. Hence the cysteine flux through the skin (blood flow times concentration) was unchanged. Nevertheless uptake of 35S-cysteine by the skin increased with supplementation from 12.8 {\textpm} 2.7 to 22.8 {\textpm} 2.7\%, resulting in a significant increase in skin utilization of cysteine for protein synthesis. The results suggest that enhancing cysteine supply within the sheep does not proportionately improve cysteine availability for protein synthesis. Instead a large proportion of the extra supply is oxidised. Additionally, although enhanced whole body cysteine supply does not improve skin cysteine supply (or flux), increased arterial cysteine concentration appears to stimulate skin cysteine transport into cells so that increased cysteine utilization for protein synthesis is still achieved. }, issn = {1176-5283}, author = {Harris PM and Lee J and Sinclair BR and Treloar BP} } @conference {40554, title = {The effect on oesophageal groove closure of water and mineral solutions drenched to cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {23-26}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The fate of mineral solutions when drenched was assessed in cows slaughtered after drenching using a dye visible in gut contents. Seven groups of 10 cows were drenched with water or solutions of magnesium oxide, magnesium chloride, magnesium sulphate, sodium chloride, sodium bicarbonate or zinc oxide in Trial 1. Frequency of closure was higher (P<0.05) for sodium bicarbonate (60\%) than for magnesium oxide or magnesium chloride (10 to 20\%). Five cows drenched with water alone showed bypass of the rumen. In Trial 2 four groups of 6 or 7 cows were drenched with water or solutions containing selenium. Hydromin or copper sulphate. Frequency of closure was higher (P<0.05) for copper sulphate (70\%) than for water or selenium (0\%). The results suggest that bypass of the rumen in response to drenching may contribute to apparent failures of bloat drenches, particularly when certain minerals are added to the drench. }, issn = {1176-5283}, author = {Carruthers VR and Phipps DE and Bakker RJ} } @conference {40603, title = {The effects of condensed tannin in Lotus corniculatus upon nutrient metabolism and upon body and wool growth in grazing sheep.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {219-222}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Lotus corniculatus containing 23 g/kg DM of extractable condensed tannin (CT) and 35 g total CT/kg DM was fed to sheep in two experiments. In both experiments half the sheep received supplementation with polyethylene glycol (PEG), which binds and inactivates CT, enabling the effects of CT to be quantified by comparing control sheep (CT operating) with PEG sheep (CT inactivated). Experiment 1 was conducted indoors, with sheep held in metabolism crates and fed hourly to determine the effects of CT upon apparent digestibility and upon plasma irreversible loss (IRL) rates of methionine, cystine and inorganic sulphate, using 35S labelling. Experiment 2 as a field trial with weaned lambs given a restricted allowance of either lotus corniculatus (CT-containing) or lucerne (non CT-containing), with or without PEG supplementation. In Experiment 1, CT slightly lowered the apparent digestibility of organic matter (0.77 vs 0.80; P<0.1), hemicellulose (0.61 vs 0.67; P=0.118) and markedly reduced nitrogen apparent digestibility (0.72 vs 0.80; P<0.01), but had no effect upon cellulose digestibility. CT increased the IRL of plasma cystine (13.1 vs 7.0 mmol/min; P<0.05) and reduced the IRL of plasma inorganic sulphate (36.8 vs 48.1 mmol/min; P<0.01) but had no effect upon plasma methionine IRL. In Experiment 2, live weight gain and wool growth were similar for sheep grazing lucerne (with and without PEG supplementation) and for sheep grazing lotus with PEG supplementation. In sheep grazing lotus, action of CT increased wool production (12.1 vs 10.9 g/d; P<0.05) and slightly increased live weight gain (203 vs 188 g/d; P=0.07). These experiments showed that CT in Lotus corniculatus increased the amount of cystine available for body synthetic reactions and increased wool growth.}, issn = {1176-5283}, author = {Wang Y and Waghorn GC and Douglas GB and Barry TN and Wilson GF} } @conference {40569, title = {Effects of herbage allowance and a high protein supplement on performance of dairy cows grazing on autumn-winter pastures}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {83-86}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Two experiments were conducted to assess aspects of the feeding value of winter pasture for lactating dairy cows. During May 1989, three groups of 10 Friesian cows were offered daily herbage allowances of 43 (High, H), 20 (Medium, M) and 13 (Low, L) kg dry matter (DM) per cow, for a four week period in early lactation. Daily herbage intakes, assessed by cutting pastures before and after grazing, were 12.4, 9.1 and 7.6 kg DM per cow, respectively. "Covariance adjusted" daily milk yields (15.6, 12.4 and 9.4 litres/cow), milkfat yields (0.64, 0.54 and 0.41 kg/cow) and protein yields (0.50, 0.36 and 0.28 kg/cow) differed significantly (P<0.01) between treatments. Responses/kg extra herbage DM eaten were 1.0 and 1.9 litres, 31 and 84 g milkfat and 43 and 52 g protein for the H-M and M-L increments, respectively. Apparent liveweight gains and proportion of cows showing oestrus were also positively related to allowance. During June 1990, two groups of 15 Friesian cows in early lactation were transferred from a herbage and grass silage ration to a high herbage allowance of 63 kg DM/cow daily. The yields of milksolids and especially protein immediately increased substantially (P<0.01); the protein concentration increasing from 3.02 to 3.70\%. For a period of two weeks, the cows in one of the groups (Treatment) also consumed 2.7kg DM daily of a high protein concentrate supplement (Brewers{\textquoteright} grain and soyabean products). Daily milk yields (Control 20.3, Supplemented 22.5 litres), milkfat yields (C 0.87, S 0.94 kg) and protein yields (C 0.75, S 0.82 kg) were increased significantly (P<0.05) by the supplement. Herbage intakes were measured and substitution rates of 0.71 and 0.45 kg pasture DM/kg concentrate DM were estimated using two alternative techniques. The combined results indicate that the nutritive value for milk production of winter pasture is relatively high, provided that a high daily allowance is offered from pastures with more than 2,000 kg DM/ha pre-grazing mass. However, the relatively large increase in milk production caused by the concentrate supplement suggests that aspects of its nutritive value may constrain high levels of milk production where allowance is high. }, issn = {1176-5283}, author = {Suksombat W and Holmes CW and Wilson GF} } @conference {40613, title = {Effects of milking frequency and machine stripping on milk yields of Dorset ewes - Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {261-262}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No astract supplied}, issn = {1176-5283}, author = {Knight TW and Gosling LS} } @conference {40618, title = {Effects of once daily milking in late lactation on cows with either low or high initial somatic cell counts}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {285-288}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The present study was carried out in order to measure the effects of once daily milking on somatic cell count (SCC) of cows which had either low SCS or high SCC at the start of the experiment in late lactation. Thirty six cows were used, 18 with low SCC and 18 with higher SCC. Nine cows from each group were randomly allocated to once or twice daily milking for the four week experimental period in March. The yields of milk, fat, protein and lactose were significantly reduced by once daily milking (P<0.01) in both groups. However, the effects of once daily milking on yields was larger for high SCC cows (interaction P<0.01). Once daily milking significantly increased the concentration of protein (P<0.001) in both groups and fat (P<0.01) in only the low SCC group. Once daily milking significantly reduced the concentration of lactose, the effect being larger in the high SCC group (interaction P<0.001). SCC (per ml) was increased by once daily milking, but the effect was significant only in the high SCC group (interaction P<0.10). The total number of cells produced per day were not affected by once daily milking. These results show that SCC can be used with confidence to identify subclinically infected cows in later lactation milked once or twice a day. The results also show that cows with a low incidence of subclinical mastitis can be milked once daily in later lactation, with much less effect on yield of milk and its constituents than would be expected in cows with a higher incidence of infection. }, issn = {1176-5283}, author = {Kamote HI and Holmes CW and MacKenzie DDS and Holdaway RJ and Wickham BW} } @conference {40604, title = {Effects of pre-lamb and conventional full-wool shearing on the productivity of ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {223-226}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The effects of pre-lamb and conventional (post-weaning) annual shearing of ewes on their productivity and that of their lambs were studies over a three year period. Ewes (n-500) were selected from a flock of 5000 mixed-age Border Leicester x Romney ewes at Massey University{\textquoteright}s Riverside property in the Wairarapa in April 1989 and randomly allocated to two equal sized groups. Both groups were managed under the same conditions until December 1991. Throughout the trial, one group was shorn after weaning in November/December and the second group was shorn prior to lambing in August. Ewe liveweight and lambing performance were measured over three years, and individual ewe fleeceweights were recorded over two full years. Pre-lambing ewe liveweights were similar for both policies in all years, while post-weaning liveweights were greater in pre-lamb shorn ewes in 1989 only. Annual fleeceweights were significantly (P<0.05) greater for the pre-lamb shorn ewes in 1990 (4.07{\textpm}0.05 vs 3.64{\textpm}0.06 kg) but not in 1991 (3.61{\textpm}0.08 vs 3.75{\textpm}0.09 kg). Lamb birthweights and weaning weights did not differ between shearing treatments. The small difference in ewe and lamb performance between the shearing treatments suggests that management factors, such as the provision of feed and shelter post-shearing, the spread of seasonal work, net income per ewe and cashflow, should determine whether a pre-lamb shearing policy is adopted. }, issn = {1176-5283}, author = {Dabiri N and Parker WJ and Morris ST and McCutcheon SN} } @conference {40624, title = {The effects of restricted suckling and prepartum nutritional level on reproductive performance of primiparous crossbred beef cows.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {307-310}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Reproductive performance was recorded in a total of 21 two-year-old Hereford x Friesian and Simmental x Friesian primiparous cows before and after restriction of calf suckling. Cows were allocated one of two pastures allowances from day 112 to 212 of gestation so that the high nutrition (HN) group gained 0.75 kg/d, and the low nutrition (LN) group gained 0.17 kg/d during mid-gestation. Suckling was suppressed for 7 days by fitting nose plates to 46-day-old calves in the restricted suckling (RS) group, whereas the normal suckling (NS) group remained as a control. Dominant follicles in the ovaries occurred in all cows by day 32 post partum and underwent a pattern of growth and atresia before first ovulation. Restricted suckling cows had a shorter interval from calving to conception than NS cows (76.0 {\textpm} 5 vs 94.1 {\textpm} 6 days, P<0.05, whereas genotype and nutritional treatment had no effect on interval to conception. However, the beneficial effect of suckling restriction on days from calving to conception only occurred in cows fed the high herbage allowance in mid-gestation. RS calves spent more time grazing during the period of attachment of nose plates and differences in behaviour remained over a further 5 days after nose plates were removed (62.4 {\textpm} 7 vs 38.6 {\textpm} 7 minutes spent grazing; P<0.001), but were lighter at weaning (146.7 {\textpm} 3 vs 162.4 {\textpm} 3 kg; P<0.01). Despite the lower calf liveweight at weaning it is concluded that manipulation of suckling through fitting nose plates to calves can be used to initiate earlier re-breeding in primiparous cows. }, issn = {1176-5283}, author = {De Nava Silva GT and Burnham DL and McDonald MF and Morris ST} } @conference {40605, title = {The effects of season on placental development and fetal growth in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {227-230}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Autumn-born lambs have been reported to have lower birth weights than spring-born lambs by 0.4 to 1.0 kg, but the physiological basis of this difference is unknown. This study examined the effects of season on fetal growth and placental development independent of the confounding effects of maternal nutrition. Romney ewes (aged 5 and 6 years) were randomly allocated to groups mated in December (n=13) or March (n=13 with a similar live weight at mating (55.6{\textpm}1.8 vs 55.7{\textpm}1.9 kg, mean{\textpm}SE, P>0.10) and managed for a similar live weight at day 140 of gestation (62.5{\textpm}1.8 vs 62.9{\textpm}1.9 kg, P>0.10). At day 140 of gestation, measures of fetal growth and placental development, adjusted for litter size, were (December- vs March-mated): individual fetal weight (4.15{\textpm}0.16 vs 5.07{\textpm}0.16 kg, P<0.001); total fetal weight per ewe (6.42{\textpm}0.18 vs 7.14{\textpm}0.22 kg, P<0.01); caruncle number (114.5{\textpm}4.1 vs 121.0{\textpm}4.2, P>0.10); placentome number (89.4{\textpm}4.2 vs 106.9{\textpm}4.3, P<0.01); caruncle occupancy, i.e. number of placentomes/number of caruncles (0.79{\textpm}0.03 vs 0.88{\textpm}0.03, P<0.05); and total placentome weight (564.7{\textpm}34.0 vs 679.0{\textpm}34.9 g, P<0.05). These results suggest that seasonal differences in birth weight of lambs are mediated not by differences in maternal nutrition but rather by a direct seasonal effect on placental size (specifically the formation of placentomes and hence total placental weight). }, issn = {1176-5283}, author = {Jenkinson CMC and Peterson SW and MacKenzie DDS and McCutcheon SN} } @conference {40623, title = {Evidence for a diffusible factor influencing the switching of ovine and bovine milk gene expression leads to identification of factors}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {303-306}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Our earlier in situ hybridisation studies have shown heterogeneous expression of milk protein genes. At some sites, a sharp demarcation of mRNA expression is seen at the basement membrane between {\textquoteright}active{\textquoteright} and {\textquoteright}inactive{\textquoteright} tissue, while at other nearby sites, a reciprocal gradient of mRNA expression about 10 cells wide is seen. The alveoli in these latter {\textquoteright}inactive{\textquoteright} sites contain leucocytes which indicates that they have been {\textquoteright}inactive{\textquoteright} longer than the former. This suggests a factor could be diffusing between {\textquoteright}inactive{\textquoteright} and {\textquoteright}active{\textquoteright} tissues and influencing milk gene expression. We used a consensus oligomer corresponding to the linkers between the fingers of zinc finger DNA binding proteins in a polymerase chain reaction performed on cDNA from {\textquoteright}active{\textquoteright} versus {\textquoteright}inactive{\textquoteright} mammary mRNA. Differences and similarities were observed in the sizes of the DNA products from each sample. Several of the bands present in the {\textquoteright}active{\textquoteright} cDNA and absent from the {\textquoteright}inactive{\textquoteright} cDNA were cloned and some were found to have homologies to zinc finger and other DNA binding proteins. It is possible that we have partially isolated a component of the pathway that maintains lactation. }, issn = {1176-5283}, author = {Molenaar AJ and Musgrave DR and Wilkins RJ} } @conference {40640, title = {Farm management implications of a seasonal price differential for factory supply milk production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {383-388}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A number of New Zealand dairy companies have proposed a differential pricing scheme that would discount the price paid for "peak milk" and provide a premium for milk supplied "off peak". A linear programming model was developed to analyse the on-farm impact of a differential milk pricing scheme. The differential pricing scheme used in the study was based on a dairy company where farmers supplied 30\% of total milk during the October/November peak and 70\% during the off-peak period (peak-to-shoulder ratio of 30:70). The impact of three price differentials of $0.82/kg MS, $1.63/kg MS and $2.45/kg MS between peak and off-peak milk was analysed. The results showed that if the case study farmer made no management changes to his system, there would be little change in the farm gross margin per hectare under a differential pricing scheme, provided the farm had a peak-to-shoulder ratio close to that used by the dairy company to set the price differential. However, returns declined by $182/ha, if the farm peak-to-shoulder ratio was 40:60 and increased by $185/ha if the ratio was 20:80. A price differential of at least $1.71/kg milksolids ($3.00/kg MF) between peak and shoulder milk, was required to reduce peak milk production significantly. As the price differential increased, the LP model selected solutions that reduced both total milk production and the ratio of peak-to-shoulder milk. Management changes selected to modify the pattern of milk production included; a reduction in stocking rate, a shift to an earlier calving date (and then a split calving), an increased lactation length, higher cow condition at calving and greater use of supplements. }, issn = {1176-5283}, author = {Gray DI and Yuretich PA and Lynch GA} } @conference {40635, title = {Farm management research in New Zealand and its contribution to animal production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {357-362}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Farm management is concerned with procedures that assist farm managers allocate limited physical, financial and human resources to achieve their personal (and family) objectives. The process of resource allocation usually occurs with imperfect knowledge, and in the context of a biological and socio-economic system over which the farm manager has incomplete control. Management functions of planning, implementation and control are used to assist decision-making and the realisation of objectives in this uncertain environment. These occur at strategic, tactical and operational levels. Early development of the farm management discipline was strongly shaped by microeconomic theory (especially production economics) and quantitative methods of analysis (mainly from operations research). More recent development of the discipline has seen the addition of the farming systems research (FSR) philosophy and the application of qualitative techniques used in the social sciences. These additions have improved the capacity of farm management research to account for the needs and aspirations of the farmer and farm family, and to consider the dynamics of the community in which they live. This holistic view recognises that farmers frequently do not exhibit economic optimising behaviour and that their decision-making processes often ignore the classical steps outlined in management textbooks. In contrast, animal scientists use a reductionist approach to investigate the animal component of the farming system, independent of the financial, social, and sometimes physical, constraints of a commercial farming situation. It is logical then that farm management specialists should work with animal scientists to interpret animal-related research within the context of farming systems. Today{\textquoteright}s increasingly sophisticated market for land-based products demands effective partnerships among all participants in the science - technology - production - processing - marketing chain. Issues such as sustainability, product quality, animal welfare and the development of effective information systems are not the preserve of any single discipline. The challenge to farm management researchers and animal scientists is to continue to develop effective working relationships in the future. }, issn = {1176-5283}, author = {Parker WJ and Gray DI and Lockhart JC and Townsley RJ} } @conference {40611, title = {Genetic and phenotypic parameters associated with lean tissue growth in Dorset Down sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {251-254}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Genetic and phenotypic parameter estimates were derived from performance data collected over nine years for the Lincoln University Dorset Down flock. Data were for animals born each spring and run at pasture. Ewes (n=922) were measured in autumn and rams (n=819) in winter. Measurements were live weight and in vivo fat and muscle depths. Genetic and phenotypic parameters were estimated using multi-variate AIREML analyses by fitting an individual animal model with animal as a random effect, birth rank, age of dam and year of birth as fixed effects and age at measurement as a covariate. Multi-variate heritability estimates ({\textpm} s.e.) for live weight, fat and muscle depths were 0.42 ({\textpm}0.04), and 0.30({\textpm}0.05) for rams and 0.26({\textpm}0.01), 0.20({\textpm}0.05) and 0.13({\textpm}0.03) for ewes respectively. Estimates of genetic correlations were generally moderate to high for the two sexes. The genetic correlation between live weight and fat depth was significantly different for the two sexes, with rams (0.42{\textpm}0.10) having a higher value than ewes (0.24{\textpm}0.02). Phenotypic correlations differed between the sexes, with estimates for ewes being slightly higher. For both sexes, parameter estimates were different from those used to derive the indices used to select for lean tissue growth, ram estimates being consistently higher while those for ewes were more equivocal. }, issn = {1176-5283}, author = {Nsoso SJ and Young MJ and Beatson PR and Bell ST} } @conference {40610, title = {Growth rates, wool production and health of Awassi and Texel crossbred ram lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {247-250}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Birth and weaning weights, liveweight gain, wool weights and characteristics, and animal health were recorded on 214 ram lambs consisting of about equal numbers of Awassi and Texel cross Romney, Coopworth and Dorset ram lambs. Changes in blood GGT concentrations were also measured in Awassi x Coopworth and Romney ram lambs following dosing with sporidesmin. Pre- and post-weaning growth rates of Awassi crossbreds were lower (P<0.001) than Texel crossbreds. Awassi crossbreds had a higher incidence of footscald and higher (P<0.05) strongyloid egg counts in their faeces in May. After dosing with sporidesmin blood GGT concentrations were higher (P<0.001) in Awassi x Coopworth than Romney ram lambs. Awassi crossbreds had lower (P<0.001) fleece weights and wool quality than Texel crossbreds. }, issn = {1176-5283}, author = {Knight TW and Thomson NA and Power MJ and Gallen J} } @conference {40563, title = {Growth-promoting and metabolic actions of recombinant ovine placental lactogen and bovine growth hormone in young lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {59-62}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {It has been shown previously that ovine placental lactogen (oPL) has a growth-promoting effect in the growth hormone (GH)-deficient dwarf rat. However, this effect has not been verified in an homologous system using animals with an intact somatotrophic axis. To examine the effects of oPL in the sheep, we injected lambs with recombinant oPL (0.1 mg/kg liveweight/day, n=16) or saline (n=16) for 21 days commencing on day 3 of life and compared their effects on body growth and energy intake with those in lambs treated with the same dose of recombinant bovine growth hormone (bGH, n=16). Circulating concentrations (ng/ml) of hormones in saline- vs bGH- vs oPL- treated lambs at day 20 of treatment were (mean{\textpm}SE): oPL, <0.5 vs <0.5 vs 12.8{\textpm}0.5; GH, 10.8{\textpm}5.0 vs 48.4{\textpm}5.0 vs 12.6{\textpm}5.0, P<0.001; insulin-like growth factor-I (IGF-1), 267.6{\textpm}14.4 vs 302.4{\textpm}14.2 vs 291.7{\textpm}14.4. Average daily gain (kg/day) during treatment was significantly (P<0.05) greater in oPL-treated lambs (0.28{\textpm}0.01) than in saline-treated (0.25{\textpm}0.01) or bGH-treated (0.24{\textpm}0.01) lambs. Similarly, there were significant (P<0.05) increases in total energy intake (over the 21 day treatment period) during treatment with oPL (112.5{\textpm}3.5 MJ ME), compared with bGH (102.0{\textpm}3.5 MJ ME) or saline (102.0{\textpm}3.5 MJ ME) treatment. It is concluded that oPL is somatogenic in young lambs. This effect may be mediated by stimulating voluntary feed intake rather than by elevating circulating concentrations of IGF-I. }, issn = {1176-5283}, author = {Min SH and MacKenzie DDS and Breier BH and McCutcheon SN and Gluckman PD} } @conference {40553, title = {Hepatic protein variation among Romneys selected for resistance or susceptibility to sporidesmin-induced liver damage. A quantitative two-dimensional polyacrylamide gel electrophoresis study}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {19-22}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Quantitative two-dimensional polyacrylamide gel electrophoresis has been used to search for variation among liver proteins in flocks of sheep which had been selected for either resistance or susceptibility to sporidesmin- induced liver damage. The goal was identification of proteins whose DNA sequences might be used to select animals for resistance to facial eczema. The quantitative gel techniques were used because of their ability to detect variability among many proteins in a single tissue sample. Differences in relative proportion were tested for 62 proteins among 5 ewes from each of the resistant and susceptible flocks. There were 7 proteins which showed statistically significant differences (P<0.05) between the flocks. When an analysis was made of changes in the relative proportions of proteins 2 days after experimental challenge of resistant flock ewes (n=8) with sporidesmin, 0.13 mg per kg body weight, 25 of 79 liver proteins showed significant change (P<0.05). This included partial loss of a 25 kDa, pI 5.7, protein which was also three times more abundant in undosed susceptible than undosed resistant females. These results are discussed in terms of the possible relationships between protein variation and the magnitude of toxic tissue damage. }, issn = {1176-5283}, author = {Lu YF and Morris CA and Towers NR and Jordan TW} } @conference {40566, title = {Herbage intake, ingestive behaviour and diet selection in sheep grazing Holcus lanatus and perennial ryegrass swards}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {71-74}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Grazing behaviour, diet selection, and herbage intake of ewes in mid- pregnancy were studied on perennial ryegrass/white clover and Holcus lanatus/white clover swards rotationally grazed at medium and high allowances (6\% and 12\% of liveweight as herbage dry matter respectively) during late autumn. Estimates of herbage mass and sward height before grazing were similar for the two pasture types. Animals on both pasture types concentrated grass rather than clover in the diet, and extrusa samples from both showed evidence of limited concentrations of condensed tannins. Herbage intake was 28\% higher from ryegrass than from Yorkshire fog swards (1410 vs 1100 {\textpm} 29 g DM/day) and 19\% greater at high allowance (1370 vs 1150 {\textpm} 50 g OM/day). Bite weight was 61\% greater for Yorkshire fog than for ryegrass (139 vs 86 {\textpm} 7.0 g OM/bite) and 30\% lower for medium allowance than for high allowance (90 vs 130 {\textpm} 7.0 mg OM/bite). Grazing time was higher on ryegrass swards and for medium allowance (610 vs 500 {\textpm} 34 mins and 620 vs 495 {\textpm} 27 mins) whereas differences in rate of biting were small. There was a small advantage in the organic matter digestibility of the herbage selected in favour of ryegrass swards (85.7 vs 82.2 {\textpm} 0.3\%), while no differences were found between herbage allowances. It is concluded that herbage intake was influenced more by nutritional than by behavioural constraints, but that these effects need to be investigated in animals of higher production potential and nutrient demand. }, issn = {1176-5283}, author = {Montossi FM and Hu Y and Hodgson J and Morris ST} } @conference {40608, title = {Hormonal and ovarian responses in Romney ewe hoggets after synchronisation and superovulation treatment.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {239-242}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Twelve, 10-month old ewe hoggets (Av LW 32.5 kg) were placed in metabolism crates under controlled lighting (11 h L:13 h D) for a 9 d adaptation period and were fed for maintenance. They were synchronized by vaginal insertion of CIDR and treated with gonadotrophins for superovulation. Of the 12 hoggets 9 had two or more successive plasma samples with > 0.9 ng/ml progesterone (P4) indicating they had ovarian activity prior to treatment. Mean P4 concentrations prior to treatment (d - 3) were 0.69 {\textpm} 0.18 ng/ml and had risen to 1.50 ({\textpm} 0.38), 1.72 ({\textpm}0.35), 1.36 ({\textpm}0.11) and 1.31 ({\textpm}0.10) ng/ml for d 0 to d 3 of treatment. On d 9, 10 and 11, prior to CIDR removal, P4 levels were back to base line levels (0.60, 0.46 and 0.57 ({\textpm}0.06) ng/ml respectively). The mean number of follicles and corpora lutea were 5.0 ({\textpm}0.95) and 1.8 ({\textpm}0.53), respectively. Total CL had a negative correlation (r = -0.64, P<0.05) with the P4 concentration on the day of CIDR removal. Six of the 12 ewes had an LH peak within 25 hours after CIDR removal. In addition, those ewes treated during late cycle tended (P>0.10) to have a better ovarian response than those treated at early or mid cycle. These results suggest it may be necessary to use two CIDR to maintain a sufficiently long period of P4 elevation. In addition, the day of the cycle that the CIDR is inserted may be important to achieve maximum response from ovulation enhancement treatment in ewe hoggets. }, issn = {1176-5283}, author = {Campbell JW and McDonald MF and Wickham GA} } @conference {40631, title = {How relevant are current and emerging genetic technologies to the beef breeding cow?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {337-344}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The genetic merit of stock in the commercial sector of the beef breeding herds is dependent on the rate of genetic gain in nucleus herds and the length of delay it takes to transfer this genetic gain to commercial herds. This paper states the factors controlling the rate of genetic gain and genetic lag and examines the impact of current and future technologies on these factors. The setting of selection objectives and opportunities for crossbreeding in New Zealand beef breeding herds are also mentioned briefly. The maximum theoretical rate of genetic gain in beef cattle herds is about 3.4sigmaT (genetic standard deviations). Current technologies should allow a rate of gain of about 0.25sigmaT but results from New Zealand beef cattle selection experiments suggest that the actual rate achieved in the industry is unlikely to exceed 0.1sigmaT. It is suggested that many new technologies becoming available will either have little impact on the rate of genetic gain or will be too expensive to apply in New Zealand{\textquoteright}s extensive beef cattle industry. Opportunities will exist for nucleus breeders who are prepared to cooperate with each other giving them a larger pool of breeding cows. The most likely genetic lag using current practices is about 10 years in the New Zealand beef cattle industry. By generating replacement females from only young parents and by accessing sires of above average genetic merit, it should be possible to reduce genetic lag to about 1 year. It is concluded that the New Zealand beef cattle industry could greatly enhance the rate of genetic gain and reduce the level of genetic lag through the application of existing technology. Furthermore, the establishment and application of sound selection objectives is an immediate priority. }, issn = {1176-5283}, author = {Blair HT and Garrick DJ} } @conference {40633, title = {In vitro production of cattle embryos: Use in beef twinning programmes.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {351-352}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {This study investigated the survival of in vitro derived embryos as single or twin pregnancies following their twin transfer to recipient cows. Abattoir-derived oocytes were matured, fertilised and then cultured for 6-7 days using our standard laboratory procedures. One hundred and forty good quality late morula and blastocysts were transferred non-surgically, in pairs, to recipient cows on day 7 of the oestrous cycle (day 0 = oestrus). Recipients were monitored by ultrasound for pregnancy up to Day 60 and embryo survival was determined. While 57 (81\%) of recipients did not show oestrus by day 21, only 39 (56\%) were pregnant on day 35 and 30 (77\%) of the pregnancies were twins (embryo survival; 57\%). Increasing stage of gestation was associated with a decrease in pregnancy rate, twin pregnancies and embryo survival (46\%, 37\% and 31\%, respectively) on day 60. The results show that while high initial pregnancy rates can be established following the transfer of two in vitro derived embryos, embryo survival drops during early pregnancy. Current research efforts are investigating factors that may influence early embryo survival in cattle. }, issn = {1176-5283}, author = {Pugh PA and Thompson JG and McGowan LT and McMillan WH and Tervit HR} } @conference {40615, title = {Increasing per cow milk solids production in a pasture-based dairy system by manipulating the diet: A review.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {267-274}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Research suggests that the genetic potential for milksolids (MS) production by New Zealand dairy cows is considerably under-exploited under current grazing conditions. There is also a growing awareness that only small improvements in MS production per cow can be achieved with pasture-only systems on high producing New Zealand dairy farms (i.e. those producing 315kg MS/cow or 1,000kg MS/ha). The review identifies nutritional limitations of a pasture-based diet as one of the barriers to further increases in per cow MS production. It is argued that further increases in per cow production on New Zealand{\textquoteright}s high producing (in terms of per cow MS production) dairy farms is contingent upon the need to balance the pasture- based diet for protein, carbohydrates, fibre, minerals and vitamins through strategic use of feedstuffs. One of the keys to successfully balancing a pasture-based diet is to obtain better data on the nutritional status of pasture throughout the year so that the most economic feedstuffs which will balance the ration can be identified. }, issn = {1176-5283}, author = {Edwards NJ and Parker WJ} } @conference {40550, title = {Influence of insulin-like growth factor-1 (IGF-1) on components of the haematopoietic and lymphatic systems}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {5-8}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Increased thymic weights have been reported in sheep selected for resistance to internal parasites and treatment with IGF-1 increases thymic and splenic weights in sheep, suggesting that IGF-1 may have a role in regulating immune function. This hypothesis was examined in four experiments using mice as a model. Expt 1 Unselected Swiss mice (n-24) were injected 2 x daily with 30 mg/d rhIGF-1 or saline for 26 days from 28 days of age. IGF-1 treatment increased spleen weight at a common body weight (118.2 vs 95.9, pooled standard error (PSE) = 6.2 mg, P<0.05), but did not affect thymic regression (thymic weights at the end of treatment: 85.5 vs 81.9, PSE = 4.0 mg). Expt 2 Unselected female Swiss mice (n=22, age = 84.8{\textpm}0.8 days) were injected 3 x daily with 30 mg/d rhIGF-1 or saline for 17 days. IGF-1 treatment increased thymic weight at a common body weight (78.4 vs 58.0, PSE = 3.0 mg, P<0.01), but had little effect on splenic weight (180.1 vs 163.0, PSE = 7.5 mg, P>0.10), Expt 3 Histological sections of spleens from High (H), Control (C), and Low (L) IGF-1 selected mice at 30 (n=30) and 120 (n=35) days of age were analyzed for the density of megakaryocytes (precursor cells for thrombocytes), and the percentage of the area covered by white pulp (lymphatic tissue). L mice had, compared to C and H mice, lighter spleens (62.6 vs 76.8 vs 89.6, PSE = 5.3 mg, at 30d; 60.2 vs 109.5 vs 114.5, PSE = 7.4 mg, at 120d; P<0.05), and a lower density of megakaryocytes (9.2 vs 13.4 vs 14.7, PSE = 1.6 n/mm2, at 30d; 2.1 vs 13.9 vs 14.3, PSE = 2.0 n/mm2, at 120d; P<0.05), but were not different in the percentage of the area covered by white pulp (16.1 vs 14.1 vs 13.4, PSE = 1.3\%, at 30d; 28.3 vs 23.1 vs 23.8, PSE = 2.4\%, at 120d). Expt 4 Mice from the three IGF-1 selection lines (n=13 vs n=13 vs n=14 for L vs C vs H, age=86.8{\textpm}2.3 days) showed no difference in spleen weights (110.8 vs 137.4 vs 139.0, PSE = 11.8 mg; P>0.10). In response to an antigenic challenge with sheep red blood cells (SRBC), there was a small effect (P=0.10) of selection line on the number of plaque-forming (immunoglobulin M (IgM)- producing) cells (PFC) per spleen (880x103 vs 954x103 vs 1187x103, PSE = 130x103), but the differences in anti-SRBC antibody titres (IgM) in the plasma (10.8 vs 11.1 vs 11.7, PSE = 0.6) were not significant. It is concluded that IGF-1 affects splenic and thymic weights independently, that it influences the density of megakaryocytes in the spleen, and that it has an effect on the number of PFC per spleen in response to a SRBC challenge. However, the biological significance of these effects is still to be established.}, issn = {1176-5283}, author = {Kuhn Sherlock B and Morel PCH and Mathis JM and Blair HT and McCutcheon SN and Marbrook J and Breier BH and Gluckman PD} } @conference {40573, title = {Isolation of cDNA subclones encoding ovine glucose transporter proteins - Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {99-100}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied }, issn = {1176-5283}, author = {Bennett BL and Grigor MR and Prosser CG} } @conference {40594, title = {Issues of sustainability in animal production and the implications for science: An international perspective.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {181-184}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Issues of sustainability in animal production in developed countries involve a trend away from intensive production systems and destruction of the environment, towards improved animal welfare and increased product quality, with an emphasis on reduced use of chemicals in production systems. The negative environmental impact and the loss of biodiversity, due to livestock production systems, are major issues in both developed and developing countries. In developing countries, desertification and deforestation, the sustainable management of wildlife systems and the need to reduce competition between humans and animals for scarce resources, are all major issues of sustainability. While the developed world is looking towards "de-intensifying" its animal agriculture, the developing regions of the world have a perceived need to intensify animal production systems in order to support increasing populations, urban growth and an increased demand for animal products. The implications for scientific research include: aiming to optimise rather than maximise production; greater emphasis on the ecological aspects of sustainable systems, maintenance of biodiversity and natural resources; and minimising external inputs and satisfying the food, income and social needs of rural communities. Scientific communities must increasingly seek international collaboration in a global approach to the challenge of sustainable animal production. }, issn = {1176-5283}, author = {Parry A} } @conference {40552, title = {Lamb weight gain and faecal egg count when grazing one of seven herbages and dosed with larvae for six weeks}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {15-18}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {One hundred and forty Polled Dorset lambs were randomly allocated to graze one of seven herbages (n = 20/herbage) and either trickle dosed (n=12) with a total of 108,000 third stage gastrointestinal nematode larvae (50\% Trichostrongylus colubriformis and 50\% Ostertagia circumcincta) over 6 weeks, or undosed (n=8) and allowed to ingest any nematode larvae on pasture. After 28 days on the trial lambs dosed with larvae had higher (P<0.001) faecal egg counts (FEC{\textquoteright}s) than undosed lambs but after 42 days egg counts did not differ (P>0.05) between dosed and undosed groups. Dosing with larvae did not significantly alter the liveweight gain (LWG). Herbage species affected LWG, being highest on lotus (Lotus pedunculatus cv Maku) and lowest on ryegrass/white clover (Lolium perenne/Trifolium repens), with other treatments being intermediate. Dosed lambs grazing chicory (Chicorium intybus) had more faecal dags than any other group of lambs. Those grazing G27 red clover (Trifolium pratense) were worst afflicted by a dermatitis type condition commonly referred to as trefoil dermatitis. Plasma pepsinogen levels differed significantly (P<0.05) only between dosed and undosed groups grazing pawera red clover, ryegrass/white clover and sulla (Hedysarium coronarium). Worm counts were undertaken on ryegrass/white clover and sulla grazed lambs. Both dosed and undosed groups grazing ryegrass/white clover had higher (P<0.05) abomasal worm counts than sulla grazed lambs, intestinal worm counts were highest in dosed lambs grazing ryegrass/white clover, intermediate in the dosed lambs grazing sulla and in undosed lambs grazing ryegrass/white clover, and lowest in the undosed lambs grazing sulla. }, issn = {1176-5283}, author = {Niezen JH and Waghorn TS and Raufaut K and Robertson HA and McFarlane RG} } @conference {40587, title = {Liveweight and fleece production from New Zealand, South African and first cross Angora goats}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {151-154}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The release of the South African Angora from quarantine will be the single factor with the greatest impacts on the New Zealand mohair industry over the next few years. In order to provide information on production under New Zealand farming conditions, trial was carried out comparing the liveweight and fleece production of South African, New Zealand and first cross South African x New Zealand (Crossbred) Angora goats from birth to two years of age. Crossbred and South African goats were significantly heavier than New Zealand Angoras at most ages. South African Angoras were heavier than Crossbreds for the first 8 months only. Fleeces from South African goats were heaviest, New Zealand Angora fleeces were lightest, while Crossbred fleece weights were intermediate between the parental breeds at all shearing times. Fibre diameter of fleeces from New Zealand goats was finer at 12 months of age (24.8 {\textpm} 0.4, 27.0 {\textpm} 0.4, 27.6 {\textpm} 0.3 {\textmu}m for New Zealand, Crossbred and South African respectively) but there were no differences at 18 and 24 months of age. Medullation and kemp levels were higher in New Zealand than South African fleeces at all sampling times. Medullation and kemp levels in the Crossbred fleeces were higher than the mean of the parent levels, indicating heterosis effects. Medullation levels did not differ in Crossbred and New Zealand fleeces at 18 and 24 months of age. Advantages of the South African Angora over the New Zealand Angora goat were confirmed in this study, however anticipated improvements in fleece quality were not achieved in the first cross. }, issn = {1176-5283}, author = {Newman S-AN and Paterson DJ and Power MT} } @conference {40641, title = {Making use of technology diffusion}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {389-392}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Diffusion is the process by which the adoption of new technologies spreads over time throughout the members of a social system. Many science institutions target their extension efforts at adoption leaders in a population, and rely upon a trickle down of the technology to spread it to the general population. Diffusion is described as resulting from the effects of farmer characteristics, technology characteristics, farming systems, and communication networks available for diffusion. The process of diffusion is enhanced by extension activities, and much can be done by scientists to improve the value of their technology to intended recipients. In order to do this, farmers should be involved during the development of technologies to identify the characteristics most important to them and their farming systems. New technologies should be evaluated for their effects upon the whole farm system and upon farmer perception. Sufficient information is needed by potential adopters for them to successfully implement new technology. The information they value most is provided by other farmers with scientific support for the essential principles they should apply. }, issn = {1176-5283}, author = {Parminter TG and Parminter IA} } @conference {40576, title = {Mammary involution in ewes: Changes in milk plasminogen and plasmin}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {107-110}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Multiparous Border Leicester x Romney ewes were weaned early (day 35 of lactation), milked to empty the mammary gland and again milked 18 h later (day 0 of experiment) to establish baseline milk yields and concentrations in milk of the proteolytic enzyme plasmin and its zymogen plasminogen. They were then divided into 3 groups to be milked 3 (n=5), 8 (n=6) or 15 (n=5) days after the day 0 milking to determine changes in concentrations and yields of plasmin and plasminogen in mammary gland secretions during involution. Yields (mean{\textpm}SE) on days 0 (groups 1 + 2 + 3), 3 (group 1), 8 (group 2) and 15 (group 3) were: secretion (g), 785{\textpm}31.2 v. 598{\textpm}94.8 v. 478{\textpm}86.8 v. 51{\textpm}66.6; plasminogen (mg), 7.8{\textpm}2.2 v. 78.7{\textpm}11.1 v. 22.4{\textpm}4.6 v. 3.9{\textpm}2.1; and plasmin (ug), 11.5{\textpm}2.38 v. 148.5{\textpm}8.00 v. 51.6{\textpm}7.92 v. 4.9{\textpm}2.32. Corresponding concentrations in the secretions were (ug/ml): plasminogen, 0.01{\textpm}0.002 v. 0.15{\textpm}0.027 v. 0.046{\textpm}0.005 v. 0.061{\textpm}0.007; and plasmin, 0.015{\textpm}0.006 v. 0.275{\textpm}0.027 v. 0.118{\textpm}0.011 v. 0.083{\textpm}0.009. There was a linear decline in the volume of secretions from day 0 to day 15. In contrast there was a transient increase (15 fold) in plasminogen and plasmin yields by 3 days after milking. These data suggest that any role of plasmin in mammary gland involution is likely to be limited to the first week after early weaning. }, issn = {1176-5283}, author = {MacKenzie DDS and Cottam YH and Knutson RJ and McCutcheon SN} } @conference {40626, title = {Managing the high performance beef cow herd - where to next?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {315-318}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Historically, the breeding cow has established its place on New Zealand sheep and beef farms as a {\textquoteright}hardy{\textquoteright} animal, able to withstand the vagaries of climate and feed supply, and for {\textquoteright}cleaning-up{\textquoteright} rough pastures generally assisting output from the ewe flock - the main enterprise. The cow has been particularly useful where contour or cost prevented cropping or conservation. In this context, pure breeds such as Angus or Hereford have served well. The traditional role of the beef cow needs to be reviewed as farmers: - move to cross-breeding and use more {\textquoteright}productive{\textquoteright} breeds - have much higher expectations of beef income relative to sheep - increase their proportion of beef to sheep - develop their properties Data from the {\textquoteright}Limestone Downs{\textquoteright} property near Port Waikato is presented to show that this {\textquoteright}new{\textquoteright} cow in the {\textquoteright}new{\textquoteright} environment presents challenges and opportunities not earlier foreseen. At Limestone Downs, three-way cross- breeding of the Angus herd started in 1984, with Hereford and Friesian bulls introduced. At that time, average calf weaning weight was 180 kg. In 1992 the last of the pure Angus cows weaned calves of 205 kg, with the 3-way cross cows weaning calves at 250 kg. Mean cow liveweight of about 420 kg has not changed since 1984. However, the liveweight of the cross-bred cows drops 34- 40 kg between calving and weaning, whereas the Angus tended to stay constant. Additional calf weaning weight has cost the cow liveweight which must be replaced before the following spring. With increased subdivision, pasture development and greater cattle numbers there is no longer the rough feed for cows to {\textquoteright}survive{\textquoteright} on. This, coupled with a cow now bred to produce a heavy calf at weaning at the expense of her own body condition if necessary, can lead to re-breeding problems and high cow losses. What of the future? We need to be clear about our expectations of the breeding cow, and perhaps accept that in the traditional role, the traditional cow needs only minor modifications. At the other end of the spectrum however, in a situation where the cow is a direct competitor for feed, we need to consider a whole spectrum of options such as twinning, as these are developed and proven. }, issn = {1176-5283}, author = {Lowe KI} } @conference {40562, title = {Measurement of steroids by enzymeimmunoassay: An environmentally friendly alternative to radioimmunoassay}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {55-58}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Enzymeimmunoassays (EIAs) for oestradiol-17b and progesterone were developed using antibody-coated microtitre plates, and steroid-horseradish peroxidase conjugates as steroid {\textquoteright}tracers{\textquoteright}. The characteristics of standard curves and the precision of measurements were comparable between the EIAs and corresponding radioimmunoassays (RIAs). The applicability of the EIAs was demonstrated by using them to measure oestradiol-17b and progesterone concentrations in media sampled daily from cultures of bovine granulosa cells. The EIAs detected the characteristic switch in cellular steroidogenic capacity from oestradiol-17b to progesterone production typical of cultured granulosa cells. There was a significant linear correlation (P<0.001) between the EIAs and RIAs in the concentrations of steroids measured in granulosa cell culture medium by the two immunoassay formats. These findings may encourage other laboratories to consider converting "in-house" RIAs to EIAs, thereby eliminating the potential health and environmental hazards associated with the radioisotopes required for RIA. }, issn = {1176-5283}, author = {Henderson KM and Hardie AHM and Camberis M} } @conference {40581, title = {Mouse mammary fat pad interacts with mitogens to stimulate epithelial growth in vitro}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {125-130}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Issues of sustainability in animal production in developed countries involve a trend away from intensive production systems and destruction of the environment, towards improved animal welfare and increased product quality, with an emphasis on reduced use of chemicals in production systems. The negative environmental impact and the loss of biodiversity, due to livestock production systems, are major issues in both developed and developing countries. In developing countries, desertification and deforestation, the sustainable management of wildlife systems and the need to reduce competition between humans and animals for scarce resources, are all major issues of sustainability. While the developed world is looking towards "de-intensifying" its animal agriculture, the developing regions of the world have a perceived need to intensify animal production systems in order to support increasing populations, urban growth and an increased demand for animal products. The implications for scientific research include: aiming to optimise rather than maximise production; greater emphasis on the ecological aspects of sustainable systems, maintenance of biodiversity and natural resources; and minimising external inputs and satisfying the food, income and social needs of rural communities. Scientific communities must increasingly seek international collaboration in a global approach to the challenge of sustainable animal production. }, issn = {1176-5283}, author = {Hovey RC and McFadden TB and MacKenzie DDS} } @conference {40637, title = {The New Zealand policy framework for sustainable agriculture and some implications for animal production research}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {369-372}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {International environmental influences are becoming increasingly important to farm management decisions on New Zealand farms. New Zealand has been active in meeting international commitments in issues such as the UNCED Biodiversity Convention, the UN Framework Convention on Climate Change, and the Montreal Protocol on Ozone Depletion. New Zealand now needs to focus on the impacts of agriculture on the environment. This paper backgrounds recent policy developments in New Zealand leading up to the release of a Ministry or Agriculture and Fisheries position paper on sustainable agriculture. The position paper defines sustainable agriculture as having environmental, economic, social and market dimensions. MAF believes that new approaches will be needed to encourage farmers to adopt more sustainable farming systems. There are market opportunities presented by providing customers with assurances of the environmental quality of our products and the processes by which they are produced. There are also issues of resource degradation that must be addressed through standards under the Resource Management Act. The influence of these changes on farming practices in New Zealand is reviewed in this paper. Issues confronting farming systems researchers and animal production scientists wishing to contribute to sustainable agriculture in New Zealand are identified. }, issn = {1176-5283}, author = {Frizelle JA and Morris SD and Walker AB} } @conference {40629, title = {Nutritional buffering: Do we make the best use of this phenomena in the breeding cow}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {329-332}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The nutritional buffering capacity of the beef cow, defined as the ability to absorb low levels of feeding without compromising productivity, is reviewed in regard to winter management. It is shown that resistance to liveweight loss is repeatable for cows within the same herd between years (correlations 0.4 to 0.8, P<0.01). However this capacity is associated with lower calf weaning weight (correlations 0.3 to 0.5, P<0.05). There was no association between the amount of winter liveweight loss and cow liveweight, calf birth weight or time to first oestrus in the cow. It is shown that these results are consistent with evidence for the variation of maintenance requirements between cows. It is suggested that the buffering capacity of the beef cow could be exploited through animal breeding or by management of early nutrition. There may be no one cow type which is optimal for all farming situations, and instead a range of cow types which are more or less able to buffer feed shortages may be preferred. }, issn = {1176-5283}, author = {Pleasants AB and Barton RA and McCall DG} } @conference {40645, title = {The on-farm impact of beef production technologies}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {413-416}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Three beef breeding cow technologies (heifer mating, dairy cross cows, and exotic terminal sire bulls) have the potential to increase cattle gross margins by 48\% and increase output from the national beef herd significantly. However, on a whole farm basis where the extra feeding levels required to implement these technologies are taken into account individual farm surpluses increase by only 21\%. Samples of farmers from the Taihape/Hunterville and coastal Hawkes Bay regions were all aware of the technologies but had chosen not to use the new technologies for rational reasons. The most frequently stated reason was that the technologies were not suitable for harsh farming environments. Other reasons stated by farmers related to the farmer not being able to provide the breeding cow herd the preferential feeding required for these technologies to express their potential. }, issn = {1176-5283}, author = {Brazendale R and Reid J and McRae A} } @conference {40647, title = {Physical performance / financial performance... Ne{\textquoteright}er the twain shall meet?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {423-428}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The historic development of farm reporting systems has meant an overemphasis upon accounting concepts and formats. The compulsion, in New Zealand, of compliance reporting inhibits reports which reflect progress toward farmer and farm objectives and the underlying nature of the production processes. The utilisation of more sophisticated planning tools and the uptake of objective measures of system performance provide an opportunity to rethink and reconstruct farm management report contents and formats. A model report is presented which attempts to harmonise the physical production processes and the financial consequences of these processes. The report undertaken for a winter milk dairy farm; extends the concept of enterprise to separate land, conservation, herd and replacement activities; clarifies input-output relationships within and between these activities; and analyses financial consequences of these relationships. The model provides; a framework for understanding the relationship between production and finance; a framework for developing comparative measures of performance which take account of systems differences which current industry benchmark{\textquoteright}s ignore; and a basis for meeting the compliance demands all individuals face. }, issn = {1176-5283}, author = {Kirton IF and Mackrell KI and Stone JA} } @conference {40617, title = {Predicting the influence of high breeding index dairy sires on farm productivity}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {281-284}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A computer modes was developed to calculate the effect of a sires genetic merit on the yields of fat, protein and milk produced by his daughters, and on their liveweight, feed requirements and achievable stocking rates. Herd statistics, costs and prices were based on average figures for 1992. The effect of a 1 unit increase in sire Breeding Indexes (BI{\textquoteright}s) for fat, protein and milk and a 1 kg increase in average daughter liveweight on marginal farm profit per hectare were +$0.48, +$0.98, -$0.36 and -$0.49 respectively in the year of the daughters first lactation. That is, in terms of effects on gross margin per hectare, an increase of 1 unit in protein BI (sire) was equivalent to either +2 fat BI (sire), -3 milk BI (sire) or -2 kg in average daughter liveweight. The net effect of a 1 kg increase in average cow liveweight across a whole herd was calculated as being a reduction of approximately $1.30 in marginal profit per hectare. Trends in future yields of milk components were predicted from an on-farm (per cow) and an industry (supply) perspective. These trends were assumed to be solely due to genetic improvement and were based on estimated rates of genetic gain in both New Zealand (NZ) and the United States of America (USA). Based on these estimates, milk supply to the industry could increase between 30-50\% in the next 30 years. This would require annual processing capacity increases in the order of 1.2 - 1.5\% per year. Over the last 16 years, increases in milk supply due to greater yields per cow (genetics + management) have only been averaging around 0.6\% per year. Careful planning may be required by the dairy industry in order to cope with future supply increases. }, issn = {1176-5283}, author = {Clark JM and Holmes CW and Garrick DJ} } @conference {40600, title = {Prediction of beef carcass yield from selected commercial cuts expressed as a percentage of side weight}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {205-208}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Given that almost all beef carcasses intended for export from New Zealand are boned out into cuts in the boning room of export plants, the feasibility was investigated of carrying the identification of individual animals from the point of slaughter through to sides in the boning room and using the weights (percentages) of selected cuts to predict the yield of saleable meat. A Ruakura beef cuts database with information from sides of 1461 bulls, 1097 steers, 320 heifers and 329 cows, all of known breeding, was used to test the accuracy of beef saleable meat yield prediction from the weights of three hindquarter cuts removed at the same time and site in the boning room. The inside round (topside), outside round (silverside) and thick flank expressed as a percentage of side weight were chosen for use alone and in multiple regression to predict the percentage of the carcass available as saleable meat. A model incorporating \% inside and \% outside and their interactions with sex (bull, steer, heifer and cow) provided useful prediction of \% meat yield (R2 0.77, RSD 2.11\%) and if hot carcass weight was added to the equation the R2 improved to 0.78 and the RSD was reduced to 2.06\%. The sum of the inside and outside expressed as a percentage of side weight gave the same accuracy of prediction of percentage saleable meat yield as when they were treated as separate independent variables. The use of thick flank gave no improvement in prediction. These results should be compared with the present system where sex class, fat class (grade) and hot carcass weight predicted yield with an R2 of 0.60 and an RSD of 2.80\% for the same set of data. }, issn = {1176-5283}, author = {Kirton AH and Bass JJ and Hogg BW and Mercer GJK and Duganzich DM and Woods EG} } @conference {40582, title = {Prenatal wool follicle development in Romney, Merino and Merino- Romney cross sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {131-134}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The prenatal development of wool follicles has been described separately for the Merino and Romney but a comparative study of both breeds and their cross has not been undertaken. This study compared the rate and timing of follicle development in midside skin samples from Romney, Merino and Merino-Romney cross (MxR) foetuses slaughtered at weekly intervals from day 76 to 144 of gestation. The development pattern of total number of follicles per unit area of skin differed between genotypes as indicated by a significant (P<0.001) genotype x gestational age interaction. The total follicle density of each genotype increased from day 76 to day 105 at which time the follicle density of the Romney peaked at 229 follicles/mm2. Total follicle density of the MxR continued to increase to between 420 and 510 follicles/mm2 between day 104 and 122 of gestation and the Merino reached a peak of 1170 follicles/mm2 at day 125 of gestation. The density of immature (i) and mature fibre-bearing (f) primary follicles (P(f+i)) did not differ (P>0.10) between genotypes over time, with each genotype reaching a maximum density of P(f+i) between days 83 and 90 of gestation. Primary follicles (P) began to reach maturity by gestational day 90 in the MxR and by day 97 in the Merino and the Romney (P>0.10). In all genotypes, secondary follicle (S) initiation began at around day 90 with a small proportion starting to form fibres by day 105 of gestation. There was a significant interaction between genotype and gestational age for both the density of S(f+i) (P<0.0001) and the density of S(f) (P<0.01). Specifically, S(f+i) increased to 175 follicles/mm2 in the Romney, 440 follicles/mm2 in the MxR and 900 follicles/mm2 in the Merino at 105, 105 and 125 days gestation respectively, after which S(f+i) density stayed relatively constant up to birth. These results indicate that follicle initiation and fibre formation in different genotypes occurs at similar ages during fetal growth. The high total follicle density in the Merino is due to a high S density which, in turn, is due to S initiation continuing for longer than in either the Romney or MxR. These data provide a model for the identification of certain physiological factors which affect secondary follicle initiation and development. }, issn = {1176-5283}, author = {Hocking-Edwards JE and Birtles MJ and Harris PM and Parry AL and Paterson E and Wickham GA and McCutcheon SN} } @conference {40557, title = {Prevalence of two inherited disorders in US Holstein cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {35-38}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The deficiency of uridine monophosphate synthase is a disorder of the de novo pathway for pyrimidine nucleotide biosynthesis. Inherited as an autosomal recessive, it results in early embryonic mortality for the homozygous recessive genotype. In the mid-1980{\textquoteright}s, heterozygotes were estimated at 1 - 2\% among US Holstein cattle. The institution of a testing program for carriers and refusal by US artificial insemination companies to accept carriers into their progeny testing programs has eliminated the condition from the top 400 US Holstein bulls. Bovine citrullinaemia is a defect of the urea cycle. Also inherited as an autosomal recessive, it results in early postnatal mortality for the homozygous recessive genotype. In 1990, heterozygotes constituted 0.3\% of US Holstein cattle. At present, no known carriers are among the top 400 US Holstein bulls. Carriers for either condition can be detected by convenient and inexpensive DNA based testing. To guard against these conditions reappearing, a modest testing program among prominent US bulls should be continued and importers should insist that imported Holstein germplasm have no evidence of these conditions. }, issn = {1176-5283}, author = {Robinson JL and Shanks RD} } @conference {40589, title = {The processing of different staple strength wools}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {159-162}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Wool from lines of Romney sheep selected for high and low staple strength and a randomly selected control line were processed into worsted yarn for handknitting (ewe hogget fleeces) and semi-worsted yarn for carpets (adult ewe fleeces). Separate lots of wool were created for each line with the fleeces chosen to ensure that the lots had similar mean fibre diameter, staple length and medullation. Hogget wool yarns were knitted into panels and the adult ewe wool yarns were tufted into carpet. In the hogget wool processing trial, increased staple strength was associated with greater mean length after carding and higher combing yields, with small improvements in yarn tenacity and in knitted panel abrasion and pilling test results. The adult ewe wool processing trial also produced a significant difference in length after carding. At high spindle speeds the high strength line performed better in spinning, producing fewer "end-breaks". The trials indicate there are real advantages for worsted and semi-worsted processing and product performance, warranting premiums for high strength wools. }, issn = {1176-5283}, author = {Maddever DC and Scobie D and Bray A} } @conference {40561, title = {A prolonged change in body composition induced by endocrine manipulation of the neonate}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {51-54}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The ability of endocrine manipulation of the neonate to effect prolonged changes in body composition was examined. Treatment of lambs with recombinant bovine somatotropin (rbST) at doses of 0.1 or 0.3 mg/kg liveweight/day for 11 weeks from birth elevated circulating ST concentrations (P<0.01) but had no effect on circulating concentrations of insulin-like growth factor-1 or on liveweight gain compared with excipient-treated lambs. However, at 8 months of age (5 months after cessation of treatment), ultrasound backfat depths (Mean{\textpm}SE) were significantly (P<0.05) higher in lambs previously treated with excipient (3.4{\textpm}0.3 mm) than in those treated with rbST at 0.1 mg/kg (2.8{\textpm}0.3 mm) or 0.3 mg/kg (2.5{\textpm}0.3 mm). In a second study, rats were treated with saline vs. 0.2 ug/g rbST vs. 0.4 ug/g rbST vs. 0.2 ug/g pituitary ovine prolactin (poPRL) vs. 0.4 mu/g poPRL for the first 21 days of life. At 120 days of age they were euthanased, selected fat depots weighed and the carcasses analysed for fat content. Neonatal treatment with rbST or poPRL significantly (P<0.05) reduced weight of the subcutaneous scapular fat depot (1.08{\textpm}0.18 vs. 0.46{\textpm}0.17 vs. 0.52{\textpm}0.18 vs. 0.50{\textpm}0.17 vs. 0.49{\textpm}0.17 g) and carcass fat content (5.88{\textpm}0.27 vs. 5.03{\textpm}0.26 vs. 4.58{\textpm}0.27 vs. 5.28{\textpm}0.26 vs. 4.70{\textpm}0.26\%) but did not influence weights of the subcutaneous abdominal, genital or perirenal fat depots. These results suggest that endocrine manipulation of the neonate may offer a means of producing desirable changes in the composition of production animals while avoiding consumer resistance to the use of hormonal growth promotants close to the time of slaughter. }, issn = {1176-5283}, author = {McCutcheon SN and Kadim IT and Wickham GA and Purchas RW} } @conference {40597, title = {Reduction of carcass fatness in overfat lambs fed low energy diets supplemented with protein}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {193-196}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Forty crossbred (Dorset Down x (Border Leicester x Romney)) overfat (ultrasonic GR 13.3 {\textpm} 0.5 mm), ewe lambs aged approximately 6 months and weighing 40.4 ({\textpm}0.8) kg live weight were randomly allocated to either an initial slaughter group or one of three dietary treatment groups on the basis of live weight and ultrasonic GR measurement. Dietary treatments consisted of three pelleted diets that contained 101 g (MP), 189g (HP) and 274g (SP) crude protein with estimated metabolizable energy contents ranging from 7.1 to 7.8 MJ per kg dry matter. Lambs were fed ad libitum for 42 days. Throughout the experiment, daily live weight gain was significantly higher for MP than HP or SP lambs (P<0.01). However, this was solely due to greater gut fill for MP lambs compared to HP and SP lambs (P<0.05). There were no significant treatment effects on mean carcass weight. However, all treatments significantly (P<0.05) reduced GR tissue depth (measured on hot carcass at slaughter) by 20\%, 19\% and 24\% for MP, HP and SP lambs, respectively. Chemical fat content in the carcass significantly decreased (8\%, 12\% and 16\%, respectively (P<0.05)). Differences between dietary treatments were not significant for these traits. M. longissimus dorsi area and protein content of the carcass were not significantly altered by dietary treatments (P>0.05). It is concluded that carcass fat in overfat lambs can be successfully reduced by feeding diets low in energy and supplemented with medium to high levels of protein without adverse effects on carcass protein. High levels of dietary protein do not appear to be necessary for this to occur. }, issn = {1176-5283}, author = {Liu AH and Young MJ} } @conference {40551, title = {The relationship between internal parasite burden, faecal egg count, and mucosal mast cells in fleeceweight-selected and control sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {9-14}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Research has shown that sheep from a Massey University flock selected for increased fleece weight (FW) for thirty-six years have higher faecal egg counts (FEC) than unselected controls (C). The purpose of this trial was to determine whether differences in FEC between FW and C sheep accurately reflected differences in adult worm burdens. In addition levels of mucosal mast cells, and their relationship with worm burden in each line were examined. Thirteen one year-old rams from each flock were housed indoors and artificially infected with larvae of three species of nematode parasite: Haemonchus contortus, Ostertagia circumcincta, and Trichostrongylus colubriformis. FECs were monitored and adult worm burdens, and levels of mucosal mast cells, determined following slaughter 28 days after infection. FECs were higher in FW than C sheep (4204 vs 300 epg, p<0.0001), as were numbers of adult Haemonchus (1151 vs 249, p<0.01) and Ostertagi (2268 vs 600, p<0.05). Numbers of Trichostrongylus (5838 vs 5266) and total worm burden (9257 vs 6115) were not significantly different between lines. A {\textquoteright}Total Pathogenic Index{\textquoteright}, calculated from the number of parasites of each species present in the total burden, was higher in FW than C sheep (3.8 vs 1.5, p<0.005). The regression coefficient relating FEC to worm burden was larger in FW than C sheep (0.35 vs 0.05 eggs per g faeces/worm, p<0.01). Levels of mucosal mast cells did not differ significantly between lines, but were inversely related to number of worms in FW sheep. There was no such relationship in C sheep. It is concluded that while the large differences in FEC between lines overestimates the difference in total worm burden, FW sheep do carry significantly more worms of the abomasal species H. contortus and O. circumcincta than C sheep. FW sheep are able to maintain superior wool production in spite of this potentially more pathogenic worm burden. The mucosal mast cell response to parasitic infection also appears to have been changed by selection. }, issn = {1176-5283}, author = {Williamson JF and Blair HT and Garrick DJ and Pomroy WE and Douch PGC} } @conference {40580, title = {Relationships between major milk whey proteins in blood plasma and milk yield in dairy cattle.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {121-124}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {We have examined the ability of co-cultured mouse mammary fat pad (MFP) to modulate the response of mouse mammary epithelial cells to a number of mitogens in vitro. In a series of 4 experiments, COMMA-1D cells were cultured with or without epithelium-free MFP obtained from the abdominal mammary glands of 23-day old virgin, female BALB/c mice. Final cell number was quantified as total DNA after 7 days. The main effect of MFP was significant in all experiments, MFP alone inducing a 6.1 to 8.2-fold increase in cell number relative to basal medium (BM) controls (P<0.001). Furthermore, this stimulatory effect of MFP synergised (P<0.02) with the mitogenic effect of 10\% foetal calf serum (FCS). Examination of the response to several mammogenic hormones indicated that insulin (10 ug/ml) alone did not increase cell number (P>0.05), and interacted with the effect of MFP (P<0.001). There was no effect of prolactin (2.5 ug/ml) either alone or with MFP, whereas hydrocortisone (2.5 ug/ml) attenuated the response to MFP (P<0.001). In the absence of MFP, insulin-like growth factor-I (IGF-I; 75 ng/ml) did not increase cell number (P>0.05), whilst epidermal growth factor (EGF; 25 ng/ml) significantly increased cell number 3.7-fold. Both of these growth factors markedly interacted with the effect of MFP (P<0.001). When cultured with the combination of these growth factors and MFP, the final cell number was 29.2 times that of BM alone (25.14 {\textpm} 0.84 vs 0.86 {\textpm} 0.12 ug DNA/well). There was no effect of prostaglandin E2 (PGE2; 0.5 ug/ml) or indomethacin (5 mg/ml), an inhibitor of prostaglandin synthesis, in the absence or presence of MFP. These findings demonstrate that a diffusible factor(s) from the MFP interacts with several regulators of mammary growth to markedly stimulate epithelial proliferation in vitro. Such a factor appears distinct from a number of classical mitogens, and may be involved in the regulation of mammary development in vivo. }, issn = {1176-5283}, author = {Morris CA and Davis SR and Eichler SJ and Cullen NG} } @conference {40558, title = {Remote Blood Sampling Device A stress free blood sampling technique for free ranging animals}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {39-42}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Changes in various blood parameters can be used to assess the relative stressfulness of farm practices. In order to overcome confounding effects of stress inherent in standard methods of blood collection, a portable remote blood sampling device ("Dracpac") has been developed and tested. Twelve heparinised blood samples can be taken from the jugular vein and stored in insulated packs on the animal. The stability of blood parameters taken from and stored on red deer was determined. Analyses of subsamples taken from a bulk initial sample over 12 hours showed that levels of cortisol, haematocrit and glucose did not significantly differ from initial values. In a second experiment stags were sampled remotely during restraint in a mechanical crush and subsequent recovery at pasture on 2 successive days. On both days cortisol, haematocrit, glucose and lactate levels were elevated during restraint and thereafter decreased significantly to reach levels substantially lower than previously reported for this species using standard methods of blood sampling. The development of this device permits reliable remote blood sampling of free ranging animals without the stress associated with manual blood sampling. }, issn = {1176-5283}, author = {Ingram JR and Matthews LR and McDonald RM} } @conference {40590, title = {Repeatability of seasonal wool growth in Merino Sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {163-166}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Wool samples were clipped from the midside of 27 Merino rams and 33 unmated Merino ewes born in 1990 at 4 or 8 weekly intervals, depending on the season, between July 1991 and January 1994. Wool growth rat and mean fibre diameter were measured. Both wool growth rate and mean fibre diameter exhibited seasonal growth cycles which were synchronous. The rhythm of the seasonal cycle for each characteristic was calculated as:- Rhythm (\%) = (Max-Min) / ((Max+Min) / 2) x 100 The rhythm for wool growth rate exceeded that for mean fibre diameter while the rhythms for both characteristics increased significantly between the first and second year but not between the second and third years. Although wool growth rate and mean fibre diameter were strongly correlated between adjacent clipping periods, the derived rhythm estimates for both characteristics were only weakly correlated between years. Adjustment of the rhythm estimates for liveweight change during the same period significantly improved between sheep repeatability of the seasonality estimates. These data indicate that a significant proportion of the variation in both wool growth rate and mean fibre diameter was, after adjustment for liveweight change, associated with permanent phenotypic differences among the sheep in the rhythm of their seasonal wool growth cycle. }, issn = {1176-5283}, author = {Sumner RMW and Clarke JN and Pearson AJ and Speedy PM} } @conference {40606, title = {Reproductive performance of ewes after grazing on G27 red clover, a low formononetin selection in cultivar Pawera.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {231-234}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {One hundred and fifty ewes grazed either on a high oestrogenic red clover (Pawera), or a new, low oestrogenic selection of red clover (G27), or control pastures before mating. The treatment groups (n = 25) and grazing lengths prior to mating were (1) Pawera, 6 weeks; (2) G27, 6 weeks; (3) G27, 12 weeks; (4) G27/Ryegrass-white clover (rg-wc), 6 weeks/6weeks; (5) Rg-wc (control 1), 6 weeks, and (6) White clover (control 2), 6 weeks. The ewes were mated as one group on rg-wc pasture immediately after the grazing treatments. Formononetin concentration was significantly lower in G27 (0.26\%) than in Pawera red clover (0.55\%) (P<0.05). Ovulation rates in ewes after the first service were similar for all treatment groups (P<0.05). The incidence of return to service was significantly higher in Pawera ewes (72.7\%) than in any of the other groups (P<0.01). The return rates for the other groups were 33.3\% (G27/6weeks), 25.0\% (G27/12 weeks), 4.8\% (G27/rg-wc), 9.5\% (rg-wc) and 14.3\% (white clover). Most ewes which were mated at the next two cycles became pregnant. It is concluded that the fertility in the ewes grazing G27 red clover was better than that in ewes grazing Pawera red clover, however there may have been some impairment in contrast to animals grazing control pasture. }, issn = {1176-5283}, author = {McDonald MF and Anwar M and Keogh RG} } @conference {40607, title = {Residual effect of a four weeks grazing of oestrogenic red clover on reproductive performance of ewes in the following six weeks.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {235-238}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The trial was conducted to study if the temporary infertility in ewes induced by oestrogenic clover, would recover accompanied by a concomitant increase in ovulation rate and/or litter size following their removal to a {\textquoteright}safe{\textquoteright} pasture. Romney ewes (N - 155) either grazed on Pawera red clover or Ryegrass-white clover (control) pasture for four weeks. Afterwards all ewes grazed ryegrass-white clover pasture and were mated in 3 groups either at the first, third or sixth week post-treatment. Mean ovulation rate was significantly lower (P<0.05) in the Pawera ewes (1.22 {\textpm} 0.06) than in the controls (1.49 {\textpm} 0.07) on respective treatments after two weeks of grazing. Ovulation rates in ewes after the 1st, 2nd and 3rd mating cycle were 1.60 {\textpm} 0.12, 1.41 {\textpm} 0.10, 1.27 {\textpm} 0.09 (red clover), and 1.64 {\textpm} 0.10, 1.67 {\textpm} 0.12, 1.30 {\textpm} 0.90 (control) respectively. Ovulation rate and litter size were similar for the two treatment groups after joining in week 1, 3 or 6 post-treatment (P>0.05). No increase in ovulation rate/litter size in Pawera group ewes was observed over and above those observed in the control ewes within the six week post-treatment period. }, issn = {1176-5283}, author = {Anwar M and Keogh RG and McDonald MF} } @conference {40612, title = {Responses to selection for lean tissue growth in Dorset Down sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {255-260}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Responses to selection using a lean tissue growth index were estimated from performance data of the Lincoln University Dorset Down flock. Data were available for ewes (n=922) born in the years 1984 - 1991 and rams (n=816) born in 1984 - 1992. Data were from two closed lines, one control and the other selected for high lean tissue growth. Initially selection was on the basis of an index comprising measurements of live weight and fat depth. Subsequently muscle depth was incorporated into the index. Ewes and rams born in spring each year were run separately at pasture from weaning (late summer) onwards. Performance testing was in the following autumn for ewes and winter for rams. Measurements were live weight and in vivo ultrasonic fat and muscle depths. Responses were calculated from regression of the difference between the line means for breeding value against time. Breeding value estimates were derived by AIREML analyses. Both sexes exhibited desirable responses in all component traits: rams; +0.290kg/yr, +0.019mm/yr and -0.013mm/yr and ewes; +0.154kg/yr, +0.028mm/yr and -0.028mm/yr for live weight, muscle and fat depths respectively. Increases in muscle depth occurred after it was incorporated into the selection index. }, issn = {1176-5283}, author = {Nsoso SJ and Beatson PR and Young MJ and Logan CM} } @conference {40636, title = {Risk perceptions and management responses to risk in pastoral farming in New Zealand.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {363-368}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The environment facing pastoral farmers in New Zealand is much more risky than it was a decade ago. This has required primary producers to identify their sources of risk and to take measures to protect their businesses against these risks. A nation-wide postal survey of 1750 dairy, sheep and beef and deer farmers was undertaken in July 1992 to determine the importance which pastoral farmers attached to different risk sources and strategies for managing risk in the post-deregulation environment. Usable responses were received from 885 farmers. A follow-up telephone survey of non-respondents found no evidence of non-respondent bias. Farmers in all three groups considered business risk to be higher than financial risk, with changes in product prices being the most important risk source. Other important risks were changes in the world economic and political situation, changes in New Zealand{\textquoteright}s economic situation, changes in input costs (except for deer farmers), rainfall variability, pests and diseases (for deer farmers), changes in producer board policies (for dairy and deer farmers), changes in government laws and policies (for deer farmers) and risks associated with accidents or health problems. A range of management responses were used to combat risk. For all three groups of farmers, routine spraying and drenching and maintaining feed reserves were the most important risk management responses. Keeping debt low, managing capital spending and maintaining both short and long term flexibility in farming operations were also considered important. Sheep and beef cattle and deer farmers also consider the marketing responses of market information, spreading sale and having more than one enterprise to be important. }, issn = {1176-5283}, author = {Martin SK} } @conference {40646, title = {The role of systems research in animal science}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {417-422}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {This paper presents challenges to the way we conduct experimentation in animal science. The theme of the paper is to show the benefits of using systems research methods in both our basic and applied animal science. The need for more accurate prediction of biological processes to achieve future breakthroughs in animal production is postulated. The use of systems research using dynamical systems models in our basic science to better understand and predict the outcome of complex biological processes is discussed. In the applied science context, difficulties in translating basic (component) research results into recommendations for improved farm performance are emphasised. Equally, difficulties in designing interpretable farm system experiments are acknowledged. Finally, examples are given of the benefits of using whole farm models to integrate component results and create a link between component research and improved farm system, field, experimental approaches. }, issn = {1176-5283}, author = {McCall DG and Sheath GW and Pleasants AB} } @conference {40595, title = {The role of women in livestock production in eastern Turkey}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {185-188}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {As part of a livestock consultancy in eastern Turkey Lincoln International consultants surveyed rural women to define their role in livestock management and their priorities for extension. The results of group interviews of 200 women in 19 villages showed that men are the agricultural decision makers, except in the few villages where men have off-farm employment. Women are responsible for milking of animals. They may assist with lambing and calving, cleaning animal houses and feeding stock. Women were aware of the effects of animal disease and poor nutrition on animal productivity, effects they observed during daily milking. They expressed an interest in receiving information on animal health. Non agricultural problems identified were effective family planning, education for girls, and water supply for those villages without water piped to a central location. }, issn = {1176-5283}, author = {Aspinall JM and Thompson KF and Hart ND} } @conference {40614, title = {Selection for or against facial eczema susceptibility in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {263-266}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Facial Eczema (FE) in sheep is associated with liver damage and considerable production losses. Romney flocks, resistant (R) and susceptible (S) to FE were established at Ruakura in 1975; a control (C) and a second resistant (R2) flock were added after 1981, the R and R2 flocks were merged in 1988, and three flocks (R, C, and S) still exist. Progeny testing was carried out in early years for ram selection, and performance testing was used after 1981. The R flock was dosed with sporidesmin in most years since 1981 at 0.15 mg/kg live weight, with the dose rate for the S flock initially 0.066 mg/kg and now reduced to 0.04 mg/kg. The C flock was divided into two groups, with one group dosed at 0.15 and one at 0.04 mg/kg, to provide an indirect comparison of the R and S flocks. Blood samples were taken after dosing to monitor liver damage via plasma gamma-glutamyltransferase (GGT) concentration. Loge GGT levels increase in proportion to increasing severity of liver damage. Thus, changes in mean loge GGT value reflect changes in relative susceptibility or resistance, with negative changes indicating increasing resistance. Two distinct peaks appear in the loge GGT distribution, centred around values of about 40 and 500 international units (i.u./l) for both the R and S flocks. The selection flocks differ in the proportions of animals at each peak, suggesting that the R and S flocks may be indirectly compared via the C flock although different dose rates were used. Annual divergence in loge GGT in the R flock relative to the C flock was -0.081{\textpm}0.047 i.u./l, and the R-flock difference from control in the most recent years averaged -1.24{\textpm}0.14 i.u./l. Divergence of the S flock from the C flock was more variable from year to year and the S-flock difference from control for the last 6 years averaged 0.48{\textpm}0.11 i.u./l. A total of 101 industry flocks have used the commercial FE testing service, Ramguard, with 9 of them testing for at least 10 years. A comparison with the Ruakura R-flock response was obtained from one such flock selecting for production traits and FE resistance since 1979. Their GGT trend was 34\% of the R-flock trend, indicating that less but worthwhile genetic progress has been obtained from using a selection programme with a multiple objective. }, issn = {1176-5283}, author = {Morris CA and Towers NR and Wesselink C and Wheeler M} } @conference {40559, title = {Separating dead from live sperm in thawed frozen merino semen does not enhance conception rate - Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {43-44}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied }, issn = {1176-5283}, author = {van Reenen GM and Griffin JFT} } @conference {40572, title = {Some effects of feeding pasture silage as a supplement to pasture on reproductive performance in lactating dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {95-98}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Supplementation of a ryegrass/white clover pasture diet with pasture silage is a common management practice in New Zealand dairy herds. The effect of this supplementation during early lactation on reproductive performance has not been investigated. Five herds of 20 cows were formed before calving commenced on June 1 1992. From August 5 to September 4, two of these herds were fed 5 kg dry matter/cow/day of pasture silage in addition to the ryegrass/white clover pasture offered to all herds. Pasture silage supplementation did not alter the intervals from calving to first ovulation, first oestrus, or to conception. However, it reduced the first service conception rate(37.5\% vs 53.3\%; (sed = {\textpm} 10.0\%), for pasture and silage and pasture only cows; respectively). A positive effect on reproductive performance of pasture silage supplementation was not demonstrated in this trial}, issn = {1176-5283}, author = {McDougall S and Clark DA and Macmillan KL and Williamson NB} } @conference {40627, title = {The stock unit system - fair treatment for the breeding cow?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {319-322}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The stock unit (SU) system has been widely used in conjunction with gross margin (GM) and analysis to make recommendations to farm managers on the comparative profitability of pastoral livestock systems. This information can be misleading, particularly where beef breeding cow policies are being compared with finishing cattle policies that involve high rates of liveweight gain (e.g. bull beef production). To illustrate the deficiencies of the SU system for standardising between different livestock enterprises, relative gross margins per stock unit (RGM/SU) were derived for two case study farms in contrasting environments. One property was located in the Manawatu region (Tuapaka), the other at Port Waikato (Limestone Downs) in South Auckland. Using the breeding cow as a base (=100), the RGM/SU at Limestone Downs for breeding ewes, bull beef, steer finishing and once bred heifers were 70, 158, 74 and 121, respectively. If these RGMIsu were expressed in terms of returns per kilogram of pasture consumed ($/kg) the rankings, relative to breeding cows (=100), were breeding ewes (51), bull beef (95), steer finishing (53) and once bred heifers (106). Corresponding values for breeding ewes and bull beef at Tuapaka were 59 and 65. Thus, the substitution rates between livestock enterprises varied substantially depending on the method used to account for differences in feed consumption. The implications of these findings for farm management decision making are discussed. }, issn = {1176-5283}, author = {Crawford HK and Lowe KI} } @conference {40638, title = {Think globally, act locally - Roles for science in enabling local actions for sustainable resource management behaviours.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {373-376}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Behavioural responses are prerequisites to sustainability and essential if the Think Globally, Act Locally concept is to become a reality. The introduction of the Resource Management Act adds weight to the requirement for land users to Act Locally, through enabling land use within the stated purpose of sustainable management of resources. The provision of knowledge to enable land users to Act Locally is one of the priority roles for science, in order that the collective values of society are supported. It is postulated that the sustainable management of resources is likely to be symbolic and may have little direct influence on behavioural outcomes. Science needs to identify the utilitarian values associated with equity, efficiency, effectiveness and knowledge itself to enable local action. Local action will in turn support the symbolic beliefs of society at large. Failure to enable local action will result in society judging science on the basis of declining sustainability i.e. symbolic and the possibility of reduced public funding for future research. A number of new science interrelationships involving society, policy and other science providers are recommended. }, issn = {1176-5283}, author = {Saunders LS} } @conference {40560, title = {Timing single fixed-time inseminations in ewes: Some new concepts}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {45-50}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The mean interval from the end of synchrony treatment to the onset of oestrus can be highly variable and as a consequence {\textquoteright}single-time{\textquoteright} inseminations may occur at other than optimal times. This study was undertaken to identify some of the factors influencing the interval to oestrus following synchrony treatment, and to develop a spreadsheet model to assist with determining the timing of AI in ewes under a range of oestrous onset patterns. Synchrony device, PMSG, time of year, and live weight tended to have important effects on the interval to oestrus. Ewe genotype and year effects were generally small. Three new concepts have arisen from the modelling exercise. Firstly, the actual timing of AI to achieve near maximum fertility depends on the mean interval to oestrus in a given flock, but not the precision of synchrony or the incidence of ewes that are synchronised. Secondly, the {\textquoteright}tolerance{\textquoteright} about this optimum time of insemination depends on how much is known about the mean interval to onset (more information means more tolerance). Thirdly, the {\textquoteright}tolerance{\textquoteright} about this optimum time of insemination depends on the maximum reduction in flock pregnancy rate that is acceptable to the flock owner (higher reduction means more tolerance). If the onset pattern in a particular flock is unknown, the {\textquoteright}universal{\textquoteright} timing for a single fixed-time AI during the breeding season is 42- 46 h after CIDR{\AE} removal, provided a drop in flock pregnancy rate of up to 5\% is acceptable. }, issn = {1176-5283}, author = {McMillan WH} } @conference {40602, title = {Ultrasound measurements predict estimated adipose and muscle weights better than carcass measurements.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {215-218}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Seventy-six 6 month old Coopworth ram lambs were scanned with ultrasound for muscle depth B, fat depth C and tissue depth GR. Lambs were slaughtered, then B, C and GR measured directly on each carcass. The hindquarters (loin and hind legs) of each carcass were boned out and soft tissue minced then analysed for lipid and protein content. From these, hindquarter adipose and muscle weights were estimated. Correlations of estimated tissue weights with ultrasound measurements were consistently higher than those with direct measurements (averaging 0.423 versus 0.293, respectively). The latter method may be more prone to measurement errors associated with displacement, damage or distortion of tissue or positioning of the measurement site. It is concluded that ultrasound measurements may be better than those made directly on the carcass for predicting tissue weights. }, issn = {1176-5283}, author = {Young MJ and Deaker JM} } @conference {40639, title = {Use of a grazing model to study management and risk}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {377-382}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A model which simulates the operation of a pastoral farm was used to perform a {\textquoteright}computer experiment{\textquoteright} on an irrigated Canterbury property. The effects of seven stocking rates, ranging from 9 to 21 stock units per hectare (SU/ha), on the performance and profitability of a self-replacing sheep flock were tested. The same experiment was performed under two scenarios (deterministic and stochastic). The deterministic scenario was equivalent to a controlled experiment, where the same pasture growth pattern occurred every year, reflecting average production in the area. The stochastic scenario introduced random variation between years, reflecting the area{\textquoteright}s natural variability in pasture production. In the deterministic experiment, maximum meat production (258 kg/ha) was obtained at 21 SU/ha, while maximum wool production (89 kg/ha) occurred at 19 SU/ha. Lambing percentage reached a maximum (135\%) at 13 SU/ha. Under the assumed set of costs and prices maximum gross margin was obtained by maintaining a stocking rate of 21 SU/ha. Introducing stochastic behaviour caused maximum production levels to decrease and gross margin was maximised at a lower stocking rate (17 SU/ha), reflecting the costs associated with weather variability. Results were used to examine the trade-off between profits and risk in stocking rate decisions. }, issn = {1176-5283}, author = {Cacho OJ and Bywater AC} } @conference {40642, title = {The use of a marketing approach to improve the development of new technologies: A case study}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {393-398}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {To predict farmer adoption of new technology, distinctive approaches have been developed within a number of social research disciplines. Some of these have focused on the range of personal characteristics of farmers. In others, marketing techniques have been used to analyse production limitations and farmer objectives to understand technology adoption. Biological scientists in New Zealand have in general acknowledged a role for social scientists in describing the economic and social conditions surrounding farmer innovativeness, but have seldom allowed that to influence the development of new technology. The central proposition this paper is that a marketing approach to the development of farm technologies will improve their adoption rate. A survey of farmers in New Zealand{\textquoteright}s Waitomo District has been previously reported in a study of their decisions to adopt beef breeding cow technologies (mating yearling heifers, using crossbred beef dairy cows, and terminal sires). In this paper ten attributes of the three technologies identified by farmers are reported as influencing their adoption or non-adoption decisions. When these attributes were included in logit regression equations, the equations were 70- 74\% correct in predicting which farmers had adopted technologies and which had not. It is concluded that new technologies will only be adopted if they meet farmer expectations when applied within farm production systems. To improve rates of adoption, researchers need a greater understanding of the attributes of new technologies that will be used by farmers to evaluate them. This can only be achieved by involving farmers at all stages of the developmental process. }, issn = {1176-5283}, author = {Parminter TG} } @conference {40644, title = {Use of simulation models in research}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {403-412}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Simulation models are increasingly used in animal research both independently and in conjunction with experimental research. This paper describes the potential uses of models within research programmes and categorises research into three main types, component research, systems research and management research. The contribution of models to component research into lactation, growth, wool growth and feed intake is reviewed. It is suggested that the concepts and data concerning interactions within the pastoral livestock system are now sufficient for a comprehensive modelling analysis of this system to be undertaken. The potential use of production systems models in management research is illustrated through the analysis of farm management factors affecting production and returns from fine wool using a pastoral sheep farm simulation model. }, issn = {1176-5283}, author = {Bywater AC and Cacho OJ} } @conference {40575, title = {The utilisation of whole body cysteine by the mammary gland of the lactating goat}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {103-106}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Three lactating Saanen goats weighing 55-71 kg, producing 1.2-3.6 kg milk/day and fed ad libitum concentrates and hay, were infused via a jugular catheter with 35S-cysteine (35S-Cys) at 9.3 mCi/min for 9 hours. Blood samples were taken hourly and mammary tissue biopsied terminally. Concentrations and specific radioactivities (SRA) of cysteine (Cys) and glutathione (GSH) were determined in whole blood, plasma and mammary tissue. Mean arterial concentrations (nmoles/g{\textpm}SE) of Cys and GSH in whole blood, plasma and red blood cells were: 71{\textpm}7, 79{\textpm}9 and 19{\textpm}8; and 823{\textpm}30, 1.6{\textpm}01 and 3426{\textpm}124 respectively. Arterial SRA in whole blood at plateau (7-9h) of 35S-Cys (352{\textpm}13 dpm/nmole) was higher than that for GSH (5.9{\textpm}0.7 dpm/nmole). However the difference between intracellular SRA for Cys and GSH in mammary gland tissue was much less (231{\textpm}23 vs 146{\textpm}13 dpm/nmole). Total uptake of Cys by one half of the mammary gland was 0.5{\textpm}0.2 g/day. Whole body irreversible loss rate of Cys was 7.3{\textpm}0.7 g/day, giving a percentage utilisation of whole body Cys by the mammary gland of 13.6{\textpm}4.3. }, issn = {1176-5283}, author = {Knutson RJ and Lee J and Davis SR and Harris PM and MacKenzie DDS and McCutcheon SN} } @conference {40643, title = {Variable animal performance and farm diversification}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {399-402}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Distributions of gross margins of breeding ewe, breeding cattle and plantation forestry enterprises were used in a linear programming model of a 651 ha Taranaki hill country pastoral farm to determine the mix of enterprises that maximised expected net farm revenue for given levels of downside risk. Risk was specified as the mean negative deviation of farm revenue from an assumed target income of $180,000. Animal performance variables used in estimating gross margins included (mean, minimum, maximum) (a) lambing percentage (92, 87, 99), (b) wool weight-kg per stock unit (5.4, 5.1, 5.8), (c) calving percentage (85, 83, 88) and (d) bull beef carcass weight-kg (229, 208, 247). The enterprise mix of 250 ha forestry and 3,791 stock units of bull beef yielded an optimum expected net farm revenue of $497,591 with little or no downside risk. Breeding ewe and breeding cow enterprises did not contribute to the optimum enterprise mix. Using a sheep/cattle ratio of 70/30 stock units, the expected net farm revenue reduced to $348,884. The optimum enterprise mix, with this ratio, was 310 ha forestry and 3,310 stock units of bull beef and sheep. The model predicted that it would be possible to increase the expected net farm revenue to a maximum of $362,923 by increasing the acceptable downside risk and the area allocated to forestry. }, issn = {1176-5283}, author = {Dake CKG} } @conference {40620, title = {The variation in milk composition from individual Beta-lactoglobulin AA and BB phenotype cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {293-296}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Studies in New Zealand have shown that bulk milk collected from groups of {\textperiodcentered}-lactoglobulin AA phenotype cows has a different composition to bulk milk collected from groups of {\th}-lactoglobulin BB phenotype cows (Hill, 1993). Although all cows used in this study were different to those used by Hill (1993), differences in composition were similar with the {\textperiodcentered}-lactoglobulin AA phenotype cow group producing milk which contained less casein, fat and total solids than {\textperiodcentered}-lactoglobulin BB phenotype cow group. No significant differences was observed in the total protein, lactose or ash content in the milk of the two phenotype groups. In comparison with the {\th}-lactoglobulin AA and BB phenotype bulk milks, large variations in composition were observed in the milk from individual cows. As all cows were fed on identical pasture and subjected to identical farm management practices these results indicate that in addition to {\th}-lactoglobulin phenotype other genetic factors can have a significant influence on the composition of milk. }, issn = {1176-5283}, author = {Hill JP and Paterson GR} } @conference {40599, title = {Variation in the pH of lamb meat within and between sheep breeds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {201-204}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Serial measurements of the pH of the longissimus dorsi muscle were obtained from lambs of 22 sire groups of six sire breeds (Experiment 1) and in 14 sire groups of lines selected for Fast and Slow Glucose Clearance (Experiment 2). Lamb sex (ewe, wether) and carcass weight and leanness had little effect on meat pH. Sire breed had significant effects on pH at 1 and 24 hours post mortem, and selection line had significant effects between 1 and 4 hours post mortem. These effects were greater on slaughter dates when pH levels were higher. Variation between individual sires was sufficient to account for some differences between sire breeds and selection lines. Differences between sire breeds and selection lines were found from the time of first pH measurement after slaughter through until ultimate pH was reached. This suggests that there were differences in the rate of glycogen breakdown to lactic acid immediately after slaughter or during electrical stimulation, as well as differences in the amount of glycogen in the muscle at slaughter. These findings confirm that lamb genotype can influence meat pH and thus will affect commercially important meat properties. }, issn = {1176-5283}, author = {Bray AR and Young SR and Scales GH} } @conference {40564, title = {Voluntary feed intake, growth and efficiency of feed conversion in growing sambar (Cervus unicolor) and red deer (Cervus elaphus)}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {63-66}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Hand-reared sambar and red deer (3 hinds and 5 stags/species) were confined indoors in individual pens and fed a pelleted diet ad libitum, to study seasonal effects upon voluntary feed intake (VFI) and body growth. Mean age at the start of the experiment was 5 months for sambar and 7 months for red deer. Red deer of both sexes showed maximum VFI and liveweight gain (LWG) in summer and minimum values in winter. Sambar of both sexes also showed seasonal cycles in VFI and LWG, but with maximum values in autumn and minimum values in spring, and with the amplitude of the cycles being much less than for red deer. Over a complete 12 month period (7-19 months of age), total LWG was similar in sambar and red deer, but total VFI was lower for sambar (p<0.01) and efficiency of food conversion (kgDM/kgLWG) more efficient for sambar than for red deer (p<0.05). When energy requirements were calculated, the amount of metabolisable energy (ME) required for both maintenance and gain were lower for sambar than for red deer. }, issn = {1176-5283}, author = {Semiadi G and Muir PD and Barry TN} } @conference {40555, title = {Within herd variability in the mineral status of grazing dairy cows in early lactation.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {27-30}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Two groups of 10 mature, crossbred cows received either a single daily dose of 10 g Mg or no supplemental Mg for two 5 day periods. Blood was sampled twice daily and urine once daily. On 3 days blood and urine were sampled four times. Serum Mg levels of 3 unsupplemented animals fell from 0.74 {\textpm} 0.034 to 0.25 {\textpm} 0.020 mmol/1 within 5 days while other animals within this group maintained serum Mg levels despite the absence of Mg supplementation. At any given sampling time serum Mg levels of individuals within the unsupplemented group varied from 0.22 to 0.88 mmol/1 and those of supplemented animals from 0.41 to 0.83 mmol/1. Mean serum Mg, Ca, Na and K concentrations did not differ between the groups. Unsupplemented animals had significantly (P<0.001) lower urinary fractional clearance ratios of Mg and Ca. The within and between animal variation in serum Mg levels was high for both Mg supplemented and unsupplemented animals. The fractional clearance of Mg in urine indicated a likely benefit from Mg supplementation for 100\% of the unsupplemented animals while serum Mg concentrations only identified 40\% of these animals. Fractional clearance of Mg in urine has potential as an indicator of animal Mg status. }, issn = {1176-5283}, author = {Dalley DE} } @conference {40591, title = {Wool characteristics of fine-wool sheep in Xinjiang Uygur Autonomous Region, China}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {167-172}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Wool production characteristics were investigated for fine-wool sheep of different genotypes at Nanshan Stud Farm, Xinjian Uygur Autonomous Region, China. Four main sets of data were available. The 1985 ewes were mixed-age Xinjian Finewool (XF). The 1986 ewe and ram hoggets were XF, F1 Australian Merino (AM) x XF and F1 Chinese Merino (CM) x XF. The 1987 ewes included CM, mixed-age XF, F1 AM x XF 2 year olds and F1 AM x XF hoggets. The 1987 rams included AM, CM and mixed-age XF. Observations were made and samples collected at shearing in June. Measured traits included: -body weight (BW); greasy fleece weight (GFW); clean yield (CY); clean fleece weight (CFW); fibre diameter (FD); crimp frequency (CF); staple length (SL): colour (CL); weathered tip (WT); dirt (DT). dirt penetration (DP): suint (SU, and wax (WX). Significant differences (P<0.05)) occurred between hogget genotype and between sexes. AM x XF hoggets produced more wool than CM x XF, or XF, but there were no differences in BW. Ewe and ram hoggets had similar BW{\textquoteright}s, but ewe hoggets produced more wool of lower FD with greater SL and WT. In the XF ewes, as age increased there were significant (P<0.05) changes in GFW, CY, CFW, SL and WX. Clean fleece production of 3-6 year old XF ewes declined by 0.17 kg/yr and SL by 0.33 cm/yr. In the XF rams, there were significant (P<0.05) increases in BW and DT with age, whilst wool production increased to 3-4 years and then declined. There were significant (P<0.05) differences between years in GFW, FD, SL, WT, DP, DT, WX and SU in hoggets, and CY, CFW, FD and SL in mature ewes. The 5 body sites of XF ewes in 1985 had significant (P<0.05) differences in fleece traits for FD, SL and CL. There were significant (P<0.001) correlations between traits for pooled data from all genotypes, ages, sexes, years and sampling sites. Negative correlations included WX with WT, DP, and DT; and DT with CY; whilst DP was positively correlated with WT. These results have implications for future sheep breeding and wool technology research, and development of programmes for improved clean wool production and quality in China. }, issn = {1176-5283}, author = {Wang XL and Lu W and Saremu and Andrews RN} } @conference {40472, title = {Animal toxicity problems perceived to be associated with different pasture types on East Coast sheep/beef farms}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {133-138}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {An understanding of behavioural principles such as the flight zone, 360 degree vision, sensitive hearing, strong reactions to novelty and effects of pressure on the body will facilitate handling and restraint of livestock. Silencing high pitched noise from hydraulic pumps and motors will reduce stress. Solid fences on races, crowd pens and loading ramps will keep animals calmer by blocking their vision. A curved race to a crush or stunning box will facilitate cattle movement because an approaching animal will not be able to see people at the other end. Wild cattle will stand still in a dark box for AI. Wild cattle in a restraint device will remain calmer if they are unable to see people inside their flight zone or a pathway of escape. It is important to keep vision blocked until the animal is completely restrained. Restraint devices should only apply sufficient pressure to hold the animal snugly in a comfortable position and to make the animal "feel restrained" without any pain or discomfort. Pressure applied with a slow steady movement will keep cattle calmer but pressure applied with jerky sudden movement causes excitement. Handlers and equipment engineers who utilize these principles can move and restrain livestock more efficiently with less stress and carcass damage. Rough handling is one of the major causes of carcass damage.}, issn = {1176-5283}, author = {Korte CJ and Smith DR} } @conference {40494, title = {Animal welfare - a threat or an opportunity for research, farming and trade}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {223-226}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {An enzymeimmunoassay (EIA) for measuring oestrone sulphate (OS) concentrations in cows{\textquoteright} milk is described. The EIA utilizes a coated antigen format in conjunction with a monoclonal antibody to OS, and is performed in microtitre dishes. An enzyme label allows OS concentrations to be quantitated by measuring changes in colour density. The EIA can be completed in under 3 h, has a sensitivity of <5 pg, and allows OS concentrations to be measured directly in small quantities (0.05 ml) of whole milk. Measurement by EIA of OS concentrations in milk samples collected throughout pregnancy confirmed the progressive rise in OS concentrations described previously using radioimmunoassay. In addition, comparison by EIA of OS concentrations in milk samples from pregnant and non-pregnant cows indicated that the EIA could be used to accurately identify pregnancy status in cows sampled 120 or more days after mating/insemination. The EIA may have a role in the dairy industry for monitoring pregnancy status.}, issn = {1176-5283}, author = {Bayvel ACD} } @conference {40462, title = {The application of controlled calving and breeding programmes to the management of large dairy herds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {87-90}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Human synthetic parathyroid hormone-related protein (PTHrP) increased mammary blood flow (MBF) following close-arterial infusion via the external pudic artery of lactating goats. MBF increased 74 }, issn = {1176-5283}, author = {Armer CC and Macmillan KL and Jellie HP} } @conference {40476, title = {An appraisal of the utility of primary cell culture from sheep udders to investigate the control of mammary function}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {151-154}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied.}, issn = {1176-5283}, author = {Wheeler TT and Callaghan MR and Davis SR and Wilkins RJ} } @conference {40467, title = {As applied agricultural scientists we serve....?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {107-110}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The timing of changes in mammary epithelium cell tight junction integrity and mammary blood flow during a 36-h milk accumulation was studied in six lactating (2208 }, issn = {1176-5283}, author = {McRae AF} } @conference {40523, title = {Awassi lamb performance in New Zealand quarantine}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {343-346}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Effects of preslaughter stress and postslaughter ageing regimes on calpain activities and indicators of meat quality were investigated in lambs selected for Fast and Slow glucose clearance (GC). Loins were aged at 11- 17 C for 4, 22 or 70 hrs and then stored frozen (-20 C) or chilled (0 C). Loins aged up to 70 hrs from Fast GC lambs that were exposed to a high level of preslaughter stress had the highest pH and lowest residual glycogen (P<0.05). Calpain activity and cooked meat shear force declined rapidly over the periods of ageing, with significant differences being found between 4 and 22, 22 and 70 hrs aged loins (P<0.05). At the same time pH increased, with a significant difference observed between 4 and 70 hrs aged loins (P<0.05). This data suggests that there is a potential conflict between the beneficial effects of ageing on tenderness and the adverse effects of ageing on the elevation of pH. Calpain I and II activities declined at different times after slaughter in loins aged 22 hrs and then stored chilled for 8 weeks. The loss in calpain I activity was closely associated with a large reduction in shear force over the first 22 hrs after slaughter. The results suggest that an understanding of the factors that control calpain activities may identify methods of improving meat tenderness.}, issn = {1176-5283}, author = {Hill FI and Ryan T and Death AF} } @conference {40485, title = {Behavioural quantification of welfare in farmed red deer}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {183-188}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {An experiment was carried out at Tokanui (Te Awamutu) and Wallaceville (Upper Hutt) over 4 years to test for the presence of sire by location interactions for faecal nematode egg count (FEC), using Romney rams from the flocks at these locations selected for high (H) or low (L) FEC. A total of 14 Tokanui rams (8H and 6L) and 12 Wallaceville rams (7H and 5L) were used in their flock of origin in the mating years 1986-90 and then in the other location in 1988-91. There were 491 lambs recorded for FEC at Tokanui, and 875 at Wallaceville. A test of the sire by location interaction was obtained by treating records from the two locations as different {\textquoteright}traits{\textquoteright}, and estimating the genetic correlation between them. Estimates were made on log transformed FEC from lambs recorded in January and again in March. Fixed effects were included for sire source and contemporary group (genetic group of dam, year of birth of lamb, sex of lamb), and sire was fitted as a random effect. For FEC in January, heritabilities for the two locations averaged 0.39 }, issn = {1176-5283}, author = {Pollard JC} } @conference {40480, title = {Beta-lactoglobulin expression in bovine mammary tissue}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {167-170}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Human factors are generally recognised as influential factors affecting the welfare and productivity of farm animals, and we have proposed that in intensive animal production systems there are some important sequential relationships between the attitude and behaviour of the stockperson towards farm animals and the behaviour, performance and welfare of farm animals. Basically we have suggested that because a stockperson{\textquoteright}s behaviour towards farm animals is largely under volitional control, this behaviour is strongly influenced by the attitudes and beliefs that the stockperson holds about the animals. Furthermore, the stockperson{\textquoteright}s behaviour towards animals affects the animals{\textquoteright} fear of humans which, in turn, may affect the animals{\textquoteright} productivity and welfare. It is the occurrence of a stress response in animals which are highly fearful of humans which places their productivity and welfare at risk. We have published data which strongly support these interrelationships between human attitude and behaviour and animal behaviour, productivity and welfare. The results of recent research in the intensive animal industries indicate the excellent opportunity which exists to improve animal productivity and welfare by training and selecting stockpersons to have desirable attitudinal and behavioural profiles towards farm animals.}, issn = {1176-5283}, author = {Ford CA and Connett MB and Wilkins RJ} } @conference {40508, title = {The Booroola (FecB) and Inverdale (FecXI) genes influence ovarian development in early foetal life}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {281-286}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Fibre growth measurements were collected on feral (F) DOES, CASHGORA (g) AND g4 DOES. Maximum and minimum down length occurred in early August and late November in all breeds. The down fleece shed between these dates. Maximum down length was 6.7}, issn = {1176-5283}, author = {Smith P and W-S O and Heath DA and Hudson NL and Davis GH and McNatty KP} } @conference {40466, title = {Brief Communication - Differences in the concentrations of glucose and related metabolites in the milk of Jersey and Friesian cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {105-106}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The objective of this study was to examine the effects of once daily milking (ODM) on yields of plasminogen, plasmin and other whey proteins and to investigate this possible role of plasmin in mammary gland involution. Twelve multiparous Friesian cows in the ninth month of lactation were placed on a ODM regimen for 7 days. Milk yields were determined and milk sampled for assay on the last day of twice daily milking (TDM) (day 1 of trial), days 3 and 7 of ODM (d4 \& d8) and again 7 days after return to TDM (d15). Data are expressed as least-square means for d1 (TDM) vs d4 (ODM) vs d8 (ODM) vs d15 (TDM) together with pooled SE (PSE). Once daily milking was associated with a significant (P<0.05) reduction in yields of milk, lactose, fat and total protein. The concentration of plasminogen increased during ODM (0.92 vs 1.52 vs 1.37 vs 0.95, PSE = 0.06 }, issn = {1176-5283}, author = {Eichler SJ and Davis SR} } @conference {40547, title = {Brief Communication - Effects of stress and nutritional changes on the ranking of cattle on plasma carotene concentrations}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {455-456}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The ability of endocrine manipulation of the neonate to effect prolonged changes in body composition was examined. Treatment of lambs with recombinant bovine somatotropin (rbST) at doses of 0.1 or 0.3 mg/kg liveweight/day for 11 weeks from birth elevated circulating ST concentrations (P<0.01) but had no effect on circulating concentrations of insulin-like growth factor-1 or on liveweight gain compared with excipient-treated lambs. However, at 8 months of age (5 months after cessation of treatment), ultrasound backfat depths (Mean}, issn = {1176-5283}, author = {Knight TW and Ridland M and Hill FI and Death AF and Wyeth TK} } @conference {40490, title = {Brief Communication - Reduced visibility lowers bull aggression}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {207-208}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Nine Romney sheep fed fresh herbages were used to study cadmium (Cd) metabolism. The major route for the excretion of ingested Cd is the faeces with less than 0.5 percent being lost in the urine. Although there was a marked net secretion of Cd into the digestive tract post duodenually a considerable net absorption occurred from the intestinal region. Absorbed Cd is mainly accumulated in the liver and kidney (>340 ng/g fresh tissue) with much small amounts being associated with muscle (<20 ng/g fresh tissue). As the variation in the intake and excretion of Cd is large, short term balance studies are less suitable as an approach to determine the rate of apparent retention of Cd in grazing animals. The use of long term slaughter techniques and kinetic studies using stable isotopes of Cd are discussed as the preferred methods to measure the absorption and retention of Cd.}, issn = {1176-5283}, author = {Chamove AS and Grimmer B} } @conference {40481, title = {Brief Communication - The nature of the microcirculation in the mammary gland of the lactating rat}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {171-172}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Of all farm production practices, intensive systems come under public scrutiny most, and intensive egg-production is often a particular source of concern. Caged hens are seen as unacceptable in most European countries due to the density of housing, barrenness of environment and restriction of "most normal behaviour patterns". In New Zealand most egg-production systems involve practices which are being questioned overseas in terms of their welfare impact. This paper presents the results of a survey of some representative New Zealand farms in the light of public and scientific concerns for animal welfare. Currently there appears to be no obvious system likely to replace laying cages and guarantee good welfare. Pressure for change, however, seems likely.}, issn = {1176-5283}, author = {Davis SR and Farr VC and Prosser CG and Thompson JG} } @conference {40543, title = {Brief Communication - Time and incidence of foetal mortality in alpacas}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {437-438}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The deficiency of uridine monophosphate synthase is a disorder of the de novo pathway for pyrimidine nucleotide biosynthesis. Inherited as an autosomal recessive, it results in early embryonic mortality for the homozygous recessive genotype. In the mid-1980{\textquoteright}s, heterozygotes were estimated at 1 - 2\% among US Holstein cattle. The institution of a testing program for carriers and refusal by US artificial insemination companies to accept carriers into their progeny testing programs has eliminated the condition from the top 400 US Holstein bulls. Bovine citrullinaemia is a defect of the urea cycle. Also inherited as an autosomal recessive, it results in early postnatal mortality for the homozygous recessive genotype. In 1990, heterozygotes constituted 0.3\% of US Holstein cattle. At present, no known carriers are among the top 400 US Holstein bulls. Carriers for either condition can be detected by convenient and inexpensive DNA based testing. To guard against these conditions reappearing, a modest testing program among prominent US bulls should be continued and importers should insist that imported Holstein germplasm have no evidence of these conditions. }, issn = {1176-5283}, author = {Ridland M and Knight TW and Wyeth TK and Death AF} } @conference {40465, title = {A case control study of anoestrum in New Zealand dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {101-104}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Clumps of mammary secretory epithelial cells were isolated from a lactating sheep udder and their mammary function in vitro was evaluated. Initially, the cells synthesized and secreted significant amounts of casein, }, issn = {1176-5283}, author = {McDougall S and Leijnse P and Day AM and Macmillan KL and Williamson NB} } @conference {40486, title = {Castration, tail docking and dehorning - What are the constraints?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {189-196}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Three experiments were undertaken to investigate the possibility that forages containing condensed tannins (CT) may affect nematode parasite burdens and their significance in lambs. In the first trial, lambs were infected with a single dose of 15000 Ostertagia circumcincta and 15000 Trichostrongylus colubriformis infective lavae. Those fed Lotus pedunculatus with or without polyethylene glycol (PEG) had lower faecal egg counts, higher liveweight gains and higher faecal dry matters than lambs fed ryegrass with or without PEG (P<0.05). In the second experiment, lambs with a low, mixed natural worm burden were grazed on sulla (Hedysarium coronarium), a CT containing legume, or lucerne, for 28 days. Lambs drenched with anthelmintic and fed sulla grew faster than those fed lucerne (321 v 215 g/day P<0.05) whilst undrenched lambs had similar growth rates on both species (250 v 220 g/day). In the third experiment, heavily parasitized lambs sired by rams selected for low faecal egg count (resistant) or conventional rams (non-resistant) were grazed on lucerne or sulla for 28 days. When anthelmintic drenches were withheld, the non- resistant sired lambs grew faster on sulla than lucerne (231 v 28 g/day; P<0.0001), as did the resistant sired lambs (181 v 72 g/day; P<0.001) respectively. Drenched non-resistant sired lambs grew faster on the sulla than on lucerne and faster than the resistant sired lambs. These results suggest that forages containing condensed tannins may have an important role to play in developing lamb production systems with less reliance on anthelmintic use for parasite control.}, issn = {1176-5283}, author = {Stafford KJ and Mellor DJ} } @conference {40544, title = {A cell culture model to detect IGF receptor expression during the cell proliferation cycle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {439-442}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Changes in various blood parameters can be used to assess the relative stressfulness of farm practices. In order to overcome confounding effects of stress inherent in standard methods of blood collection, a portable remote blood sampling device ("Dracpac") has been developed and tested. Twelve heparinised blood samples can be taken from the jugular vein and stored in insulated packs on the animal. The stability of blood parameters taken from and stored on red deer was determined. Analyses of subsamples taken from a bulk initial sample over 12 hours showed that levels of cortisol, haematocrit and glucose did not significantly differ from initial values. In a second experiment stags were sampled remotely during restraint in a mechanical crush and subsequent recovery at pasture on 2 successive days. On both days cortisol, haematocrit, glucose and lactate levels were elevated during restraint and thereafter decreased significantly to reach levels substantially lower than previously reported for this species using standard methods of blood sampling. The development of this device permits reliable remote blood sampling of free ranging animals without the stress associated with manual blood sampling. }, issn = {1176-5283}, author = {Ord R and Callaghan M} } @conference {40503, title = {Changing the sex ratio at birth in lambs, calves and deer: Implications for productivity and genetic gain in breeding flocks and herds in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {259-262}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Progesterone (P4), oestradiol benzoate (ODB) and prostaglandin F2a (PGF) have been used separately and in combination to synchronise oestrus in cattle by reducing the luteal phase of the cycle or delaying pro-oestrus after luteolysis. This latter mechanism can result in precise synchrony but with reduced fertility. In the process of attempting to improve synchrony and fertility, a series of four trials was completed with dairy heifers. Each trial was based on the use of a CIDR-B device for 7 to 10 days with or without 10 mg ODB in a gelatin capsule and with an injection of PGF from 2 to 4 days before device removal or at device removal. The results of these trials showed that injecting PGF before device removal could improve synchrony (in terms of animals inseminated at 48 h after device removal) but reduced pregnancy rates to first insemination by 5\% to 10\%. Incorporating ODB delayed the post-treatment interval to oestrus and insemination with a 7-day CIDR regime but improved synchrony with a 9 or 10 day CIDR regime. If the use of ODB was combined with an injection of PGF 4 days before CIDR device removal as part of a 10-day CIDR programme, the 48 h post-treatment synchrony rate was 93\% and the pregnancy rate was 56\%. Excluding the ODB from this programme reduced the 48 h synchrony rate to 87\% and the pregnancy rate to 45\%. These results are additional evidence that combing ODB with P4 is altering ovarian follicle wave patterns with consequent effects on synchrony patterns and fertility.}, issn = {1176-5283}, author = {McMillan WH} } @conference {40505, title = {Combination treatments for synchronising oestrus in dairy heifers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {267-270}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Twelve mature Romney ewes were housed and fed to maintain a constant bodyweight for 14 months. Monthly midside samples were collected and individual fibres measured by projection microscope for fibre and medulla diameter. Medullated fibres were observed in fibre diameter classes between 14 and 70 }, issn = {1176-5283}, author = {Macmillan KL and Taufa VK and Day AM} } @conference {40537, title = {A comparison of carcass and meat characteristics and organ weights of castrate and entire male buffalo and cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {407-412}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Research has shown that sheep from a Massey University flock selected for increased fleece weight (FW) for thirty-six years have higher faecal egg counts (FEC) than unselected controls (C). The purpose of this trial was to determine whether differences in FEC between FW and C sheep accurately reflected differences in adult worm burdens. In addition levels of mucosal mast cells, and their relationship with worm burden in each line were examined. Thirteen one year-old rams from each flock were housed indoors and artificially infected with larvae of three species of nematode parasite: Haemonchus contortus, Ostertagia circumcincta, and Trichostrongylus colubriformis. FECs were monitored and adult worm burdens, and levels of mucosal mast cells, determined following slaughter 28 days after infection. FECs were higher in FW than C sheep (4204 vs 300 epg, p<0.0001), as were numbers of adult Haemonchus (1151 vs 249, p<0.01) and Ostertagi (2268 vs 600, p<0.05). Numbers of Trichostrongylus (5838 vs 5266) and total worm burden (9257 vs 6115) were not significantly different between lines. A {\textquoteright}Total Pathogenic Index{\textquoteright}, calculated from the number of parasites of each species present in the total burden, was higher in FW than C sheep (3.8 vs 1.5, p<0.005). The regression coefficient relating FEC to worm burden was larger in FW than C sheep (0.35 vs 0.05 eggs per g faeces/worm, p<0.01). Levels of mucosal mast cells did not differ significantly between lines, but were inversely related to number of worms in FW sheep. There was no such relationship in C sheep. It is concluded that while the large differences in FEC between lines overestimates the difference in total worm burden, FW sheep do carry significantly more worms of the abomasal species H. contortus and O. circumcincta than C sheep. FW sheep are able to maintain superior wool production in spite of this potentially more pathogenic worm burden. The mucosal mast cell response to parasitic infection also appears to have been changed by selection. }, issn = {1176-5283}, author = {Purchas RW and Thomson NA and Waghorn GC and Death AF} } @conference {40525, title = {Comparison of seasonal wool growth pattern and colour variation in fleece weight selected and control Romney flocks}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {351-354}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Two trials were conducted to assess the effect of kiwifruit vinegar on a number of production parameters in sheep. Trial A evaluated the effect of kiwifruit vinegar (8.2g/100ml, as acetic acid) on lamb liveweight gain, fleece production (midside growth rate, yield and colour), and internal parasite burdens. Trial B evaluated the effect of kiwifruit vinegar on two-tooth liveweight change prior to mating, and subsequent fertility. In trial A 138 ewe lambs were randomly assigned to one of four treatment groups: i) "Extender 100" Albendazole drench capsule + 10 ml vinegar, ii) "Extender 100" Albendazole drench capsule only; iii) normal drenching (trigger level 1500 epg) + 10 ml vinegar, iv) normal drenching. The only trait for which there was strong evidence of an effect was wool yield which decreased in response to kiwifruit vinegar. Vinegar treated lambs tended to have reduced faecal egg counts during the period of the trial. In trial B 140 two-tooth ewes were randomly assigned to one of two treatment groups: i) 15 ml vinegar administered at 12, 8, 4 and 1 weeks prior to mating; ii) control. Reproductive status was assessed by ultrasound 38 days after removal of the ram. No significant differences were found in liveweight or in reproductive status between the group groups. Evidence from these two trials would suggest that any effect of kiwifruit vinegar on performance traits in sheep is small and not necessarily beneficial.}, issn = {1176-5283}, author = {Wuliji T and Weatherall IL and Andrews RN and Dodds KG and Turner P and Wheeler R} } @conference {40449, title = {A comparison of the effect of split and single applications of nitrogen fertiliser on dairy production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {33-36}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The objectives of this study were to measure within day variation and day-to-day variation in selected metabolites in serum and milk samples obtained from animals in a herd of 20 Holstein-Friesian cows which grazed ryegrass/white clover pastures during peak lactation in October. In the first trial, the 20 cows were milk and blood sampled at 0630 h, 1030 h and 1430 h on 3 October and at 0630 h on the following day. Average metabolite concentrations in serum were within the ranges indicated by a regional laboratory as being normal for healthy cattle, but significant differences were associated with sampling time and among individual animals within this range. Blood and milk urea nitrogen (BUN and MUN) and blood beta hydroxybutyrate (BOH) concentrations increased by 1.82 }, issn = {1176-5283}, author = {Penno JW} } @conference {40512, title = {The date of onset of puberty in ewe lambs as an indicator of the ability to breed out-of-season}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {299-302}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Half-sib heritability estimates were derived from ewe lamb progeny of the Woodlands Romney selection project. Ultrasonic subcutaneous fat depths (C) were measured with a Delphi probe at 5, 6, 8 and 14 months of age. Heritability estimates at each age were 0.31 (SE=0.12), 0.45 (0.11), 0.29 (0.06) and 0.28 (0.09) respectively. A Toshiba Sonolayer SAL-22A B-mode ultrasonic scanner was used to measure muscle width (A), depth (B) and GR tissue depth at 14 months of age and resultant heritability estimates were 0.07 (0.05), 0.26 (0.09) and 0.39 (0.11), respectively. Genetic correlations among ultrasonic fat depths at different ages ranged from 0.81-0.95 (SE 0.06-0.12) with higher values for those of closer temporal separation. Phenotypic correlations were consistently about 0.3 below the corresponding genetic correlations. Ultrasonic GR had a high heritability estimate and a high genetic correlation with fat depth at 14 months of 0.84 (0.08),but its genetic correlations with fat depths at earlier ages, were lower ranging from 0.55 to 0.72. The genetic correlation of hogget fleece weight with fat depth at 8 months of age was 0.09 (0.15), and the genetic correlation between 8 month liveweight and fat depth was 0.38 (0.13); similar relationships were found for fat depths measured at other ages. The heritability estimate for muscle depth B was moderate and close to that reported for carcass measurements. In contrast, the estimate for muscle width A was lower than reports for carcass measurements perhaps reflecting limitations in the ultrasonic technology used. The results indicate that ultrasonic measurements are useful selection criteria in breeding programmes to alter carcass traits.}, issn = {1176-5283}, author = {Smith JF and Parr J and Johnson DL and Duganzich DM} } @conference {40493, title = {Does intensive pig farming have a viable future? - Concerns over housing and welfare}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {219-222}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Progesterone (P4), oestradiol benzoate (ODB) and prostaglandin F2a (PGF) have been used separately and in combination to synchronise oestrus in cattle by reducing the luteal phase of the cycle or delaying pro-oestrus after luteolysis. This latter mechanism can result in precise synchrony but with reduced fertility. In the process of attempting to improve synchrony and fertility, a series of four trials was completed with dairy heifers. Each trial was based on the use of a CIDR-B device for 7 to 10 days with or without 10 mg ODB in a gelatin capsule and with an injection of PGF from 2 to 4 days before device removal or at device removal. The results of these trials showed that injecting PGF before device removal could improve synchrony (in terms of animals inseminated at 48 h after device removal) but reduced pregnancy rates to first insemination by 5\% to 10\%. Incorporating ODB delayed the post-treatment interval to oestrus and insemination with a 7-day CIDR regime but improved synchrony with a 9 or 10 day CIDR regime. If the use of ODB was combined with an injection of PGF 4 days before CIDR device removal as part of a 10-day CIDR programme, the 48 h post-treatment synchrony rate was 93\% and the pregnancy rate was 56\%. Excluding the ODB from this programme reduced the 48 h synchrony rate to 87\% and the pregnancy rate to 45\%. These results are additional evidence that combing ODB with P4 is altering ovarian follicle wave patterns with consequent effects on synchrony patterns and fertility.}, issn = {1176-5283}, author = {Barnett JL and Hemsworth PH and Cronin GM} } @conference {40471, title = {Drying off management and the use of management aids on seasonal supply dairy farms}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {127-132}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied.}, issn = {1176-5283}, author = {Parker WJ and Gray DI and Lockhart JC and Lynch GA and Todd EAG} } @conference {40478, title = {The effect of an extended milking interval on mammary blood flow and tight junctions between mammary cells in goats}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {159-162}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Hereford x Friesian cows were used to compare the calf and cow performance of 66 single-calved cows (Single Cows) rearing only their own calf (Single Calf) and 45 contemporary single-calved cows (Foster Cows) rearing their own calf (Own Calf) plus a foster calf (Foster Calf). Fostering was succesful in 85\% and 95\% of attempts in 1990 and 1991, respectively. Mean weaning weight was lowest in the Foster Calf group but comparable in the Own Claf and Single Calf groups (140 vs 194 vs 202 kg, PA field trial at Flock House over a three year period (July 1989 - March 1992) compared the performance of grazing bulls alone at three stocking rates (3.0,3.7 and 4.5 bulls/ha) with grazing bulls at 3.0 bulls/ha with an increasing stocking rate of goats (3,7, and 13 Angora does/ ha). The respective stocking rates in stock units @/ha) for the six respective treatments from bulls alone at increasing stocking rate to bulls with goats at increasing stocking rate of goats were 15,19,23,18,21, and 26 su/ha respectively. Weaner bulls were brought onto the farmlets in November each year and all rising 2 year bulls were sold off the farmiets over January to April at 18-21 months of age.

Bull growth rates were significantly depressed by increasing the stocking rate of bulls but were unaffected by an increasing stocking rate of does. Bulls in the bull/goat treatment at 26 su/ha grew at a similar rate to bulls alone, stocked at 15 su/ha. Goat performance; kidding, kid fleece weight and doe fleece weight were not affected by goat stocking rate. However at the high doe stocking rate, kid liveweight at\ weaning and doe liveweight (March) was reduced (P\<0.01 and P\<0.05 respectively).\  Stocking rate treatments had little effect on the economic farm surplus (variation between $680/ha for the least profitable $730/ha for the most profitable treatments).\  However with a more buoyant mohai market and a more robust/productive strain of Angora goat ie. the Zimbabwe Angora, it is assumed the bull/goat system would be more profitable than bulls alone.

Although goats were not complementary to bull beef production they were also not competitive with bulls over the stocking rates investigated.

}, issn = {1176-5283}, author = {Thomson NA and Power MT} } @conference {40538, title = {The evaluation of kiwifruit vinegar as a stock feed}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {413-416}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {One hundred and forty Polled Dorset lambs were randomly allocated to graze one of seven herbages (n = 20/herbage) and either trickle dosed (n=12) with a total of 108,000 third stage gastrointestinal nematode larvae (50\% Trichostrongylus colubriformis and 50\% Ostertagia circumcincta) over 6 weeks, or undosed (n=8) and allowed to ingest any nematode larvae on pasture. After 28 days on the trial lambs dosed with larvae had higher (P<0.001) faecal egg counts (FEC{\textquoteright}s) than undosed lambs but after 42 days egg counts did not differ (P>0.05) between dosed and undosed groups. Dosing with larvae did not significantly alter the liveweight gain (LWG). Herbage species affected LWG, being highest on lotus (Lotus pedunculatus cv Maku) and lowest on ryegrass/white clover (Lolium perenne/Trifolium repens), with other treatments being intermediate. Dosed lambs grazing chicory (Chicorium intybus) had more faecal dags than any other group of lambs. Those grazing G27 red clover (Trifolium pratense) were worst afflicted by a dermatitis type condition commonly referred to as trefoil dermatitis. Plasma pepsinogen levels differed significantly (P<0.05) only between dosed and undosed groups grazing pawera red clover, ryegrass/white clover and sulla (Hedysarium coronarium). Worm counts were undertaken on ryegrass/white clover and sulla grazed lambs. Both dosed and undosed groups grazing ryegrass/white clover had higher (P<0.05) abomasal worm counts than sulla grazed lambs, intestinal worm counts were highest in dosed lambs grazing ryegrass/white clover, intermediate in the dosed lambs grazing sulla and in undosed lambs grazing ryegrass/white clover, and lowest in the undosed lambs grazing sulla. }, issn = {1176-5283}, author = {Williamson JF and Morris ST and Harvey TG} } @conference {40488, title = {Ewe maternal behaviour score and ewe and lamb activity from birth to suckling}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {201-202}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {An experiment was conducted to examine the ability of Saanen kids to develop an effective resistance to re-infection by Haemonchus contortus. Kids were divided into three groups. Those in Groups I and III had received colostrum at birth while those in Group II were removed from their dams at birth in order to deprive them of colostrum. All kids were reared in the absence of parasites. At the start of the study they were 10-14 weeks of age. Each animal was given 350 infective larvae of H. contortus per kg liveweight during weeks 0, 6 and 17. During week 16 all kids in Group III were treated with levamisole to remove infections prior to re-infection. Faecal nematode egg counts (FEC) were determined at weekly intervals throughout the trial. All animals were killed to determine worm burdens 8 weeks after the final dosing with larvae. FEC of all groups peaked 5-6 weeks after each infection. Re-infections at weeks 6 and 17 were followed by continued declining egg counts in all three groups. Although worm counts for the three groups were not significantly different, establishment rates based on total larvae given after anthelmintic treatment were higher in Group III (15.2\%) than in Group I (7.0\%) or Group II (6.0\%) even though both had remained untreated. Female worms dominated males when infections were superimposed (Group I - 1:0.42; Group II - 1:0.44) however, female and males were found in roughly equal proportions when infections were removed by anthelmintic prior to challenge at 17 weeks (Group III = 1.06:1). These data suggest that, in Saanen kids, recruitment into the population is affected by repeated exposure to H. contortus in the presence of an existing worm burden. One explanation is that the natural death rate may be similar to the recruitment rate however, given the similarity in worm numbers and the continuing decline in FEC across treatments, worm fecundity would have to have been depressed dramatically by some mechanism in order to effect this result. Further work is on-going to resolve these and other issues.}, issn = {1176-5283}, author = {Parker RJ and Nicol AM} } @conference {40450, title = {Experiences with on-off grazing in early lactation on dairy farms in Northland}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {37-40}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {In an observational study of nine commercial dairy herds over two springs (four in 1990 and five in 1991) where cows grazed pasture alone, negative associations were found between blood (or milk) urea levels and milkfat and milk protein production, and positive associations of urea levels with pasture protein to soluble carbohydrate (N/Sol.CHO) ratios. Statistical analyses using principal component analysis of two datasets from spring 1990 and spring 1991 indicated that a high proportion of variation (73\% in 1990, and 33\% in 1991) in the variables measured was explained by the above relationships. Analysis of variance of the PC scores showed that these relationships were between-farm effects and not related to seasonal change with time (P<0.001). Additional data from 35 dairy herds in September 1991 also supported the associations found. Reproductive performance in the nine herds (conception rate and submission rate to AB mating) was also associated negatively with urea levels. Variations in the nutrient composition of spring pasture during the spring are presented. The correlation between N/Sol.CHO ratio and milk urea levels was high (r=0.69). Further work is needed to clarify cause and effect relationships.}, issn = {1176-5283}, author = {Blackwell MB} } @conference {40479, title = {Expression of milk genes in ruminant mammary tissue, is it subject to local controlling factors?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {163-166}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {To assess whether reducing visibility would also reduce aggression in farmed bulls, we put 2 newly-formed groups of 20-month old Friesian bulls into two types of paddocks. Those animals in paddocks where visibility was obscured by pine trees showed about one-eighth the level of aggression as those put into a bare grassy paddock. It seems likely that vision is a modifier of aggression in bulls as in some other species.}, issn = {1176-5283}, author = {Molenaar AJ and Davis SR and Wilkins RJ} } @conference {40469, title = {Extension agents can perform more effectively through an appreciation of individual learning styles}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {115-119}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The levels of the A and B variant forms of }, issn = {1176-5283}, author = {Paine MS} } @conference {40483, title = {Facility design in relation to animal behaviour, stress and bruising}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {175-178}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Animal welfare is becoming increasingly recognised as an important component of the quality assurance guarantees sought by both domestic and international consumers of primary products of animal origin. Consumers are being influenced by "conscience factors", rather than cost, and are now moving to take a "conception to consumption" interest in farming and abattoir practices and the associated animal welfare standards. Perceptions of New Zealand{\textquoteright}s welfare and husbandry practices thus play an important role in favourably positioning products in premium-priced international markets. It is important to be able to sustain, both scientifically and ethically, the New Zealand approach to animal welfare. This is especially important where New Zealand practices differ or even conflict with the practices of trading partners. In a market-responsive economy, these consumer preference trends highlight the need to present New Zealand{\textquoteright}s produce as grown in a welfare- conscious, environmentally sensitive, sustained-yield manner.}, issn = {1176-5283}, author = {Grandin T} } @conference {40475, title = {Factors affecting the production of lactose by ovine mammary cells in vitro}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {147-150}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The present public and scientific interest in the welfare of farm livestock has caused traditional management procedures, including castration, tail docking and dehorning, to be scrutinised as causes of stress (stressors). This laudable scientific endeavour is however subject to a range of constraints. Major constraints are the subjective nature of distress, and the consequent difficulty of identifying indices which can be used confidently to quantify it. Nevertheless, behavioural and physiological indices have been identified by comparison with human responses to aversive stimuli, and allow distress to be assessed in animals. Changes in plasma cortisol concentrations, reflecting the activity of the hypothalamic-pituitary-adrenal system, are commonly used as an index of distress in farm livestock exposed to stressors. Judged thus, the distress caused by castration or tail docking of sheep and cattle apparently depends on several factors including the procedure itself, the age of the animal, the method used, the species and possibly the prior method of rearing. Little is known about the distress caused by dehorning of cattle. Several factors can confound the assessment of distress. They are: (1) balancing the objectivity of the measured indices with subjective judgements about what are acceptable and unacceptable levels of distress; (2) ensuring that the parameters used do indeed reflect distress, and not other phenomena; (3) avoiding erroneous predictions, based on anthropocentric projections and not scientific observations, about expected distress levels in situations which have not yet been examined; and (4) meeting the high cost of rigorous studies in this complex area in which a wide range of factors may affect the outcome. Reducing the distress caused by castration, tail docking or dehorning may be achieved by choosing an age when the distress response is least, choosing the least distressing method, or using anaesthesia (local, general) or systemic analgesia. When a method is identified which causes the least distress, its widespread use on farms should not be recommended unless it is also practicable. To do so will not benefit either the livestock concerned or the industry. Political and trade pressures related to overseas perceptions of New Zealand animal welfare standards require responses based on rigorous scientific assessment. Those responses are likely to involve, as appropriate, vigorous defences of current practices or the adoption of new approaches.}, issn = {1176-5283}, author = {Davis SR and Eichler SJ and Callaghan MR and Grieve RCJ and Prosser CG} } @conference {40452, title = {Farm monitoring - Review of the Northland focal farm scheme}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {43-46}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Genetic evaluation of dairy cattle in New Zealand is based on a system originally developed in the 1960s. Major developments in database capability and statistical techniques have taken place over the intervening years. From the mix-1980s a major redevelopment of the information and processing system for cows took place. In 1991, a major review of the sire evaluation system was initiated. A Best Linear Unbiased Prediction (BLUP) procedure has been developed based on an animal model. Implementation of a prototype system is being investigated. In contrast to the existing technique, the prototype involves a concurrent evaluation of cows and sires in all breeds using a repeatability model. This model provides breeding values for every animal (cows with one or more performance records and ancestral animals). The Livestock Improvement database has information on some 10 million animals over more than 50 years. Use of the prototype described in this paper will become routine for ranking of dairy sires from 1994 and will increase rate of genetic gain in the dairy industry by improved accuracy of evaluation and reduced bias. The improved accuracy will result from use of all known genetic relationships among animals. The current system: does not adjust the evaluation of a sire for the merit of its mates dam; ignores sons{\textquoteright} evaluations in the evaluation of parents; ignores daughters information in the evaluation of dams. Reduced bias will result from concurrent evaluation across breeds. The current system compares animals to within-breed bases. The assumed model is identical for sires and cows in the prototype system. Furthermore, partitioning of a breeding index (BI) into its components based on information from parents, individuals and progeny is simpler than the current system which uses a recursive method for updating evaluations. Additionally, partitioning of a BI into components will provide useful diagnostic information (particularly for progeny test bulls). Interpretations of PI (production index) and BI information on reports for farmers and AB companies will be similar to the current system.}, issn = {1176-5283}, author = {Johnson KD} } @conference {40533, title = {Fat colour and meat colour in different breeds of steers in five consecutive years raised on pasture and slaughtered at 30 months of age}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {389-392}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Three experiments were carried out to determine the effects of short term nutritional changes, stress and changes in carotene content of the diet on plasma carotene concentrations (PCC) and the relative ranking of the cattle for PCC. None of the treatments affected the ranking of the cattle for PCC even though the changes in dietary carotene intake caused large changes in mean PCC.}, issn = {1176-5283}, author = {Barton RA and Pleasants AB} } @conference {40468, title = {Goals and management strategies of dairy farmers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {111-114}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Previous in situ hybridisation studies from our laboratory have shown that expression of certain milk protein genes is very high in some areas of the mammary glands of sheep and cattle, while in other areas containing an abundance of fat globules, it is virtually zero. We wished to determine if this heterogeneity was due to local variations in the concentrations of lactogenic hormones and/or their receptors. Artificially increasing the local concentration of lactogenic hormones in the sheep udder was attempted by inserting time release capsules containing prolactin, hydrocortisone and insulin directly into the gland up to one week before sacrifice. The local concentration of prolactin, and the milk gene expression relative to controls, appeared unchanged by the implants. The immunoreactivity of prolactin and its receptor in the mammary epithelial cell cytoplasm and in particular, the nuclei, were demonstrated and appeared to vary with the secretory activity of the cell.}, issn = {1176-5283}, author = {Valentine I and Hurley EM and Glass W} } @conference {40445, title = {Grazing management strategies for the production of fine Merino wool in North Island conditions}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {15-18}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Twenty four, three-week old Friesian calves were fed restricted levels of milk replacer and ad libitum levels of either ensiled roughages (R) or cereal-based pellets (P). The roughage diet consisted of ensiled lucerne- molasses (Chaffhage), followed by a mixture of Chaffhage and ensiled maize-molasses (Stockhage). The calves were weaned off milk over a two week period once they reached 70 kg. Diet R calves grew significantly faster (P<0.001) and finished the trial significantly sooner (P<0.05), based on unfasted weekly liveweight data. However, no differences were observed in fasted body weight gain. Diet R was consumed in significantly (P<0.001) larger quantities and resulted in a significantly (P<0.001) greater fasting weight loss at the end of the trial. No carryover effects were observed in terms of subsequent growth rate in heifer calves at pasture following weaning. Energy digestibilities of Chaffhage and diet P (measured using 8 bull calves following weaning) were not significantly different. No carryover effects in the ability of calves reared on R or P to digest pasture were observed. It is concluded that ensiled roughage can be consumed in sufficient quantities by young calves to produce acceptable levels of liveweight gain.}, issn = {1176-5283}, author = {Litherland AJ and Haack N and Paterson DJ} } @conference {40444, title = {Herbage allowance - intake - production relationships in continuously stocked winter- and spring-lambing ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {11-14}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The potential of by-products from fruit and vegetable growers and processors to serve as supplementary feeds for dairy cows in the Hawkes Bay region, which traditionally experiences poor summer pasture growth, was assessed. A total of 75 000 tonnes (wet matter) of by- products were produced by the six growers and processors surveyed, mainly between January and June. Peak by-product output occurred in April when an estimated 15,000 tonnes of wet matter was produced. Industry disposal costs ranged from $10 to $33/tonne wet matter. The metabolisable energy values (MJ ME/kg DM) of by-products were at least equivalent to those of high quality spring pasture (e.g. carrot 11.3, apple pomace 13.7), but nitrogen levels (\% in DM) were low compared to those recorded in pasture (e.g. corn 1.0\%, apple pomace 1.9\%). A linear programming analysis of a Hawkes Bay dairy farm indicated that farmers could afford to pay up to 15.5 cents/kg DM for additional feed from May to October and 26.7 cent/s kg DM during the remainder of the year if milkfat prices were $6/kg. These shadow values indicate the maximum price that could be paid for transport and feeding costs for by-products on the model farm.}, issn = {1176-5283}, author = {Morris ST and Parker WJ and Burnham DL and Reynolds GW and McCutcheon SN} } @conference {40524, title = {Heritability of ultrasonic fat and muscle depths in Romney sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {347-350}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Twelve buffalo (5 bulls \& 7 steers) at c.33 mo of age were compared with 16 Friesian cross cattle (6 bulls \& 10 steers) at c. 29 mo of age. The 2 species had not been run together, but were slaughtered and processed concurrently. Carcass weights were unaffected by species or castration (mean=258.6 kg). Relative to cattle, buffalo had shorter carcasses, higher dressing-out percentages, greater fat depths, more kidney and pelvic fat, and lower eye-muscle areas (all P<0.01). Buffalo had heavier hearts and spleens (P<0.001), and lighter livers and weights of rumen digesta (P<0.001). Buffalo rumen digesta contained fewer particles over 4.0 mm, but the size of particles in the abomasum was similar for both species. Yields of commercial cuts did not differ between buffalo and steers, but cattle steers had more fat trim, less meat, heavier striploins, and a higher ratio of hind-to forequarter meat than bulls (all P<0.05). Relative to the cattle, buffalo carcasses had lighter inside and cube roll cuts, but heavier outside flats, more fat trim, and a higher proportion of forequarter meat (all P<0.05). Buffalo fat was less yellow. Ultimate pH of cube-roll (M. longissimus) samples were higher for bulls than steers within cattle, and higher for cattle than buffalo (each P<0.05), possibly because the buffalo had been handled more. Other quality differences that could have been pH-related were the lower shear values (indicating more tender meat) and lower water-holding capacity (each P<0.01) of buffalo meat. However, colour (L*, a*, b* values), and sarcomere lengths were similar. Intramuscular fat levels were similar for meat from buffalo and cattle steers, but were much lower for bull beef. This is the first set of cattle/buffalo comparative data for carcass and meat quality collected under New Zealand conditions and will be of value when evaluating the role of Buffalo in this country.}, issn = {1176-5283}, author = {McEwan JC and Clarke JN and Hickey SM and Knowler KJ} } @conference {40521, title = {Hormone/metabolite levels in young rams as predictors of genetic merit for backfat depth and fleeceweight}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {335-338}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Three newly developed electronic lamb carcass grading probes (Hennessy Grading Probe, AUS-Meat Sheep Probe, Swedish FTC Lamb Probe) and one developmental probe (Ruakura GR lamb probe) were tested for accuracy in classifying 6 groups, each of approximately 50 lamb carcasses. They were assessed for accuracy and suitability for use on- line on the lamb dressing chain for objectively classifying lamb carcasses. Probe measurements were compared with manual GR (sometimes used at present) and Toland (can measure total tissue depth between the ribs) probe measurements for accuracy of predicting both GR on the right side of each carcass, and also carcass water (indicating muscle) and fat content. All probes combined with carcass weight accounted for over 70\% of the variation (R2) of GR right with the GR left prediction accounting for 92\% of the variation in GR right. The 3 commercial electronic probes used at chain speed combined with carcass weight could account for 36- 49\% of the variation in \% water and fat with the manual GR probe (right) doing only slightly better on the chilled carcass. Chilled carcass measurements are expected to give better results. The electronic probe results are consistent with overseas results where probes are in use for objectively grading the carcasses of meat animals.}, issn = {1176-5283}, author = {Kuhn B and Blair HT and Purchas RW and McCutcheon SN} } @conference {40542, title = {Horse serum contains a novel insulin-like growth factor binding protein}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {433-436}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Pastures growing on soils fertilised with phosphatic fertilisers accumulate cadmium (Cd) in their plant tops in proportion to substrate concentrations. Sheep grazing pastures absorb some of this Cd. To quantify the rate with which Cd is accumulated in sheep tissue, three replicated 0.4 ha blocks were fertilised with either 333 kg/ha of single superphosphate only (control) or amended with CdSO4 to give 274g Cd/ha (high-Cd), and set stocked with 10, three months old Romney wether lambs. Cadmium (Cd) concentrations were determined in liver, kidney, proximal duodenal and skeletal muscle tissue of sheep, ingesting either (means }, issn = {1176-5283}, author = {Prosser CG and McLaren RD} } @conference {40509, title = {How effective are exogenous progestins in mimicking the function of the corpus luteum of female cattle?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {287-290}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Relationships were assessed between circulating concentrations of urea, creatinine, thyroxine (T4) and triiodothyronine (T3), measured at 5, 9 and 13 months of age in young Romney rams, and performance of ram{\textquoteright}s ewe progeny. Five rams were chosen at random from each of the fleeceweight- selected and control lines of a long-term selection experiment. Average performance of their progeny (n = 6 to 12 per ram) was evaluated for hogget greasy fleeceweight (adjusted for age-of-dam, birth rank, date-of-birth) and yearling ultrasonic backfat depth (adjusted as previously but also for liveweight). There was no significant relationship between progeny yearling backfat depth and sire{\textquoteright}s urea, creatinine or T4 concentration at any age of measurement of the sires. However, backfat depth of the progeny was negatively correlated with sire{\textquoteright}s circulating T3 levels at both 5 months (r = 0.76, P<0.01) and 13 months (r = -0.59, P<0.10) of age. Hogget greasy fleeceweight was negatively associated with both urea (r= -0.48 and r= -0.45, respectively at 5 and 13 months) and creatinine (r= -0.63 and r= -0.53, respectively at 5 and 13 months) concentrations in the sire at 9 and 13 months of age respectively, but only the association with creatinine concentrations was significant (P<0.05). Progeny hogget fleeceweight was positively associated with sire T3 levels at 5 months of age (r= 0.62, P<0.10) but negatively associated with sire T4 levels at both 5 months (r= -0.55, P<0.10) and 9 months (r= -0.65, P<0.05) of age. Results of this preliminary study suggest that plasma concentrations of creatinine, T3 and T4 may be worthy of more extensive investigation as potential markers of genetic merit for backfat depth and fleeceweight in sheep.}, issn = {1176-5283}, author = {Kinder JE and Roberson MS and Kojima N and Werhman ME and Sanchez T and Cupp AS} } @conference {40528, title = {How reliable are sheep pedigrees?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {363-370}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Ligand blotting analysis of serum from the horse using radiolabelled IGF-I revealed a protein at 96 kDa which was not present in serum from goat, cow, sheep, deer or donkey. These latter species all displayed five labelled bands in the range 24 to 41 kDa. Conversely these were only weakly labelled in serum from the horse. Size exclusion chromatography of horse serum pre- incubated with radiolabelled IGF-I revealed reduced binding in the 130 kDa peak compared with goat plasma and ligand blotting analysis indicated that 96 kDa protein was present in this peak. The 96 kDa protein from horse serum binds IGF-I and IGF- II specifically and appears to be unique to this species. The nature of this protein is at present unknown.}, issn = {1176-5283}, author = {Crawford AM and Tate ML and McEwan JC and Kumaramanickavel G and McEwan KM and Dodds KG and Swarbrick PA and Thomson P} } @conference {40487, title = {Humane slaughter: an achievable goal?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {197-200}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Multiple anthelmintic resistance ivermectin (IVM), morantel (MOR), oxfendazole (OXF) was first demonstrated in 1988 from a goat property in New Zealand. Total spelling of all anthelmintics on the site has not been a management option. Since detection, a strict drench rotation has been adopted - levamisole (LEV) 1988-89, IVM 1990 and combination product 1991-92. IVM has been used very strategically as animal health demanded, 2 occasions in 1988, 6 in 1990 and twice in each of 1991 and 1992. In 1992 surveillance monitoring of anthelmintic status using lambs indicated that LEV remained highly effective (99.3\%) against the resistant Ostertagia spp. but there was a subtle shift downward for IVM (87.5\%). The alternate milbemycin, moxidectin (MOX), removed 99.9\% of the Ostertagia spp. population. Stability of resistance is an important issue to address when designing and evaluating management options to delay or restrict resistance and minimise the impact on farming profitability. These results suggest that anthelmintic rotation and strategic use of IVM have not had a significant effect on the field isolate over the past 5 years. Currently in the field, there appears to be a significant difference in efficacy between IVM and MOX despite their close structural similarities. It is proposed that MOX will not be used on the site but efficacies will be monitored at regular intervals.}, issn = {1176-5283}, author = {Cook CJ and Devine CE and Maasland SA and Gilbert KV} } @conference {40536, title = {Impact of pre- and post-mortem factors on calpains and meat quality in lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {403-406}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Increased thymic weights have been reported in sheep selected for resistance to internal parasites and treatment with IGF-1 increases thymic and splenic weights in sheep, suggesting that IGF-1 may have a role in regulating immune function. This hypothesis was examined in four experiments using mice as a model. Expt 1 Unselected Swiss mice (n-24) were injected 2 x daily with 30 mg/d rhIGF-1 or saline for 26 days from 28 days of age. IGF-1 treatment increased spleen weight at a common body weight (118.2 vs 95.9, pooled standard error (PSE) = 6.2 mg, P<0.05), but did not affect thymic regression (thymic weights at the end of treatment: 85.5 vs 81.9, PSE = 4.0 mg). Expt 2 Unselected female Swiss mice (n=22, age = 84.8}, issn = {1176-5283}, author = {Sun YX and Bickerstaffe R and Bray AR and Keeley G and Young S and O{\textquoteright}Connell D and Mason S} } @conference {40491, title = {Improving productivity with better stock handling}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {211-213}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The ingestion of pasture with a high infection rate of endophyte may cause a variety of pathological conditions in livestock, such as ryegrass staggers, diarrhoea, hypothermia and gangrene. This experiment was designed to ascertain the function of the immune system under such conditions. Mixed age ewes were grazed during the summer months, on either high endophyte or low-endophyte ryegrass pastures. Lymphocytes were separated from peripheral blood samples by density gradient centrifugation, and subjected to an in vitro lymphocyte proliferation (lymphoblastogenesis) assay, using the mitogens phytohaemagglutinin (PHA), lipopolysaccharide (LPS), concanavalin-A (Con-A) and intestinal nematode (Trichostrongylus colubriformis) antigen. There were significant differences (P<0.05) in the response to selected mitogens, between the group grazing high versus low endophyte pasture at 14 days (PHA) and 21 days (PHA and Con-A) after the commencement of differential grazing. The animals on high endophyte pasture showed higher stimulation indices. LPS or nematode antigen had no effect on the cultured lymphocytes. As LPS is stimulatory for Bursal-derived (B) lymphocytes and PHA and Con- A for Thymic-derived (T) lymphocytes, it would appear as if material from the high endophyte pasture affected the latter cell population. It is unknown as to whether these effects on the immune system are important, in vivo.}, issn = {1176-5283}, author = {Hemsworth PH and Barnett JL and Coleman GJ} } @conference {40501, title = {Intake and excretion of cadmium in sheep fed fresh herbage}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {251-254}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {In two trials, ewes (n=16 per group) that were potential recipients for embryo transfer grazed on a high oestrogenic red clover (Pawera), a newly developed low oestrogenic red clover (G27) and Ryegrass-White clover (Control) pastures. The ewes grazed the respective pastures during 12 days of intravaginal sponge insertion, and for a further 23 days after induced oestrus. The mean (}, issn = {1176-5283}, author = {Grace ND and Rounce JR and Lee J} } @conference {40448, title = {Intake and liveweight change of hoggets grazing pastures differing in dead matter content in autumn}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {29-32}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {White clover herbage in the vegetative stage of growth has a high nutritive value for milk production, but he high crude protein content could be better utilised if cows were given a suitable readily fermentable carbohydrate source. Six rumen fistulated Friesian cows in late lactation were housed in metabolism cages and fed either fresh white clover herbage or white clover and maize silage (50:50). The experiment was a cross over design that allowed measurement of nutrient intake, rumen function and milk production. At similar digestible organic matter intakes (9.6 kg/d vs 9.9 kg/d), replacing 50\% of the white clover dry matter with maize silage reduced crude protein intake by 30\% (3 kg/d vs 2.1 kg/d), and urinary N excretion from 251 gN/d to 137 gN/d without affecting milk yield (12.6 l/d vs 12.51 l/d) or milk protein output (400g/d vs 413 g/d). Rumen pH was similar for both treatments (6.1 vs 6.0) but there was a higher utilisation of neutral detergent fibre (2.6 kg/d vs 3.4 kg/d) when the cows were fed the mixed diet. The excess intake of nitrogen when the cows were fed white clover only was calculated to be largely wasted as ammonia absorbed from the rumen and excreted as urinary urea.}, issn = {1176-5283}, author = {Hawkins C and Betteridge K and Costall DA and Liu Y and Vallentine I and Parker WJ} } @conference {40497, title = {Internal parasites and lamb production - a role for plants containing condensed tannins?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {235-238}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {An intensive evaluation of the hormones that are primarily involved in regulating reproductive function in cows treated with progestins was undertaken and comparisons were made to cows with a functional corpus luteum. Cows with a functional corpus luteum were found to have reduced circulating luteinizing hormone (LH) and oestradiol than cows treated with a single progesterone releasing intravaginal device (PRID), norgestomet (progestin used in Syncro-Mate-B synchrony) or melengestrol acetate (progestin used for oestrous synchrony in the USA). If greater doses of progesterone than that released from a single PRID are used, concentrations of LH and oestradiol are like those of control cows in the midliteal phase of their oestrous cycle. In addition, conception rates are significantly improved when greater doses of progesterone are used compared to that of cows in which oestrus is synchronised with a single PRID. We propose that one reason for reduced conception with oestrous synchrony programmes presently in use is the failure of the progestins to effectively mimic the function of the corpus luteum.}, issn = {1176-5283}, author = {Niezen JH and Waghorn TS and Waghorn GC and Charleston WAG} } @conference {40482, title = {Introduction - Farm animal welfare contract}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {173}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Pig housing has recently been under scrutiny, resulting in some recommendations for adult pigs that may involve less individual housing. Such recommendations have obvious implications for the future viability of the pig industry. Two questions that arise are, 1) are the recommendations scientifically valid and 2) what is the likelihood of developing alternative systems? In relation to the first question, a number of experiments have been conducted on the welfare of pigs in individual and group housing systems. The overall conclusion from this research is that it is the design of the housing system that is important for welfare and not the system per se. In relation to the second question, an alternative system has been developed in The Netherlands that involves indoor group housing for pregnant and lactating pigs. Part of the system is probably directly applicable to dry sow housing in Australia and New Zealand, while the farrowing and lactation components of the system require considerable development before it is applicable to commercial environments. While there is no doubt the industry will have to change and adopt either modifications of current housing designs or totally new housing systems, past experience would indicate pig producers are fairly innovative and are very prepared to adopt new ideas that have been shown to work. It is the scientist{\textquoteright}s role to make certain that recommendations are scientifically valid and that producers are provided with the options to choose from to make their farm viable.}, issn = {1176-5283}, author = {Matthews LR} } @conference {40526, title = {Investigation into the possibility of a major gene for fleece weight in screened sires}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {355-358}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {This study investigated the effect of a progesterone containing intravaginal CIDR (Controlled Internal Drug Releasing) device on plasma progesterone and luteinizing hormone (LH) concentrations during 14-day device insertion and the subsequent oestrous cycle of fallow deer (Dama dama). Blood samples were collected from 4 entire does at 20 minute intervals for periods of 8-12h on three occasions following device insertion (i.e. insertion, mid-treatment and withdrawal) and on Days 0, 5, 12 and 19 of the subsequent oestrous cycle. Plasma was analysed for progesterone and LH concentrations by radioimmunoassay. Plasma progesterone values were elevated (>6 ng/ml) and LH values reduced (<1 ng/ml) during device insertion relative to pre-insertion values. Plasma LH concentrations were highest on Day 0 of the oestrous cycle, with a marked increase in the pulse amplitude. One doe exhibited a pre-ovulatory LH surge. Plasma progesterone increased from <0.5 ng/ml on Day 0 to 1.5-4.2 ng/ml on Day 12 (luteal phase) and high amplitude progesterone pulses were exhibited by all does on Day 19 (onset of luteolysis). The study has demonstrated that CIDR devices deliver sufficient progesterone to inhibit ovulation and the declining plasma LH concentrations during device insertion support a hypothesis of negative feedback by progesterone on LH secretion.}, issn = {1176-5283}, author = {Wuliji T and Dodds KG and Fennessy PF and Andrews RN and McEwan JC and Turner P and Wheeler R and Hawker H} } @conference {40496, title = {An investigation of sire by location interactions for faecal nematode egg counts in lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {231-234}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The aim of this study was to gain evidence that the FecB and FecXI genes influence ovarian development in foetal life. Foetuses which were homozygous carriers of the Booroola gene (BB), Inverdale gene (II), heterozygous carriers of the Inverdale gene (I+) and non-carriers of both the Booroola (++) and Inverdale genes (++) were recovered at days 40 or 90 of gestation. To eliminate the effects of litter size in the Booroola study, equal numbers of BB and ++ embryos were transferred to recipient ewes. Subsequently no gene-specific differences in litter size were noted at the equivalent of days 40 and 90 of gestation. From these studies the FecB gene was shown to affect body weight, the weight of the mesonephros, and development of germ cells. In essence, at day 40 the mean body weight and mean weight of the mesonephros were lighter in the BB foetuses compared to the ++ animals (P<0.05). Moreover the development of the BB ovaries appeared to be retarded relative to that of the ++ ovaries with respect to mitosis and meiosis of germ cells and also the timing of germ cell atresia. In the Inverdale foetuses, which were recovered after natural matings, differences were observed at the level of the ovary but none were noted with respect to body weight, or weight of mesonephros. At day 40 of gestation the ovaries of the putative II foetuses were significantly lighter (P<0.05) than those of the I+ or control animals. Moreover at day 90 the ++ and putative II ovaries contained significantly fewer (P<0.05) germ cells (i.e. ~110,000) compared to those in the authentic or putative I+ animals (i.e. ~240,000). The differences in either the Booroola or Inverdale foetuses were not accompanied by any significant differences in plasma or pituitary concentrations of follicle-stimulating hormone or plasma inhibin. The results are consistent with the notion that the FecB and FecX genes influence ovarian development in foetal life.}, issn = {1176-5283}, author = {Morris CA and Bisset SA and Baker RL and Watson TG and Johnson DL and Wheeler M} } @conference {40522, title = {Liveweight and body condition change through pregnancy as a predictor of ewe litter size}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {339-342}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Data from 95 lamb carcasses (2 data sets) and 90 bull carcasses were used to examine relationships between objective measures of carcass muscling and subjective scores of muscularity or conformation. Objective indexes calculated for lamb carcasses included muscle to bone ratios (M:B), muscularity indexes (MUSC) for both the leg and the whole side, the ratio of eye muscle depth to width (B:A), weight-adjusted eye muscle area and carcass weight per unit length. Similar variables were calculated for beef carcasses except that the weights of three commercial leg cuts were used in place of dissected muscle weights. Leg MUSC had the closest relationships with subjective scores of muscularity or conformation (R2\% = 69 to 80\% for lambs and 56\% for bulls), with leg M:B being only slightly inferior (R2\% = 62\% for lambs and 652\% for bulls). Side MUSC or M:B were the next best as predictors, but variables based on the eye muscle were poor. Carcass weight per unit length showed close relationships with subjective scores in some cases but its usefulness is limited by the fact that it can be influenced by fatness and is breed related. These results support the contention that measures of M:B may not always reflect muscularity scores because they are based on weights rather than depths and lengths. It is concluded that the objective measures of MUSC used here reflect subjective scores satisfactorily, given that subjective scores have limitations with respect to repeatability. MUSC based on the femur and the muscles or cuts surrounding it, in particular, may constitute a useful objective standard for use in the industry.}, issn = {1176-5283}, author = {Judson HG and Nicol AM} } @conference {40464, title = {Liveweight, feed intake and feed conversion efficiency of lactating dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {95-100}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A method was developed to isolate mammary cell clumps (acini), from lactating sheep and maintain these in culture for more than 48 h. Performance of these cells was assessed by the measurement of lactose secreted into media using a sensitive bioluminescence assay. Lactose production was dependent upon cell density at seeding, lactose output per cell being 5-6 fold higher (6-7 fmol/cell/h) at 0.25x10 6 cells per ml medium compared to 2.5x10 6 cells per ml medium over 24 h of culture. Lactose output declined with time in culture, irrespective of cell density, falling to <1 fmol/cell/h over the period 24-48 h. 2-deoxy glucose uptake by mammary cells tended to increase with time in culture. 2-deoxy glucose uptake was significantly higher in cells from starved sheep (p<0.05) and in cells cultured in medium containing foetal calf serum, insulin, hydrocortisone, prolactin and prostaglandin E2 (p<0.001). Lactose output of acini was not affected by starvation of the ewe for 18 h before removing mammary tissue, and increased slightly (11\%) at low cell density in response to the additions of hormones and/or foetal calf serum to culture medium (p<0.05).}, issn = {1176-5283}, author = {Holmes CW and Wilson GF and Kuperus W and Buvaneshwa S and Wickham B} } @conference {40545, title = {Measurement of relative levels of radioactivity in labelled tissue sections using image analysis}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {443-448}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied }, issn = {1176-5283}, author = {Ord R and Hodges A and Nixon A and Molenaar A and Dobbie P and Kirk S} } @conference {40531, title = {Metabolic changes in sheep divergently selected for plasma IGF-1}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {381-384}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The detection of small amounts of biologically active material in animals may require quantification of radioactive label. Here we compare several image analysis methods for quantifying relative levels of radioactive probe detected by x-ray film or photographic emulsion. Total RNA "dot blots" and ovine muscle sections were probed for the presence of muscle actin mRNA using 35S-labelled riboprobes. Bound probe was detected by x-ray film in both cases. The probed sections were further exposed to photographic emulsion, while the dot blots were individually quantified by scintillation counting. Bound probe was quantified macroscopically by digitisation of optical density (OD) and thresholding of the x-ray film image. Dot blot image ODs were correlated with scintillation counts (r>0.96), demonstrating that the levels of mRNA detected in tissues by autoradiography are proportional to cellular mRNA concentration. Densitometry of section macroautoradiographic images can therefore be useful in determining relative probe signal at the tissue level. When probe was quantified microscopically by counting silver grains in emulsion autoradiographs, simple thresholding correlated with manual counts (r=0.88) but was unreliable at higher grain densities. Processing of the gray image gave a more direct estimate of silver grain density (r= 0.98).}, issn = {1176-5283}, author = {Sherlock RG and Blair HT and Kuhn B and MacKenzie DDS and Breier BH and Gluckman PD and McCutcheon SN} } @conference {40453, title = {Milk Production and Production Index Comparisons in Mixed Breed Dairy Herds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {47-50}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Liveweight, milk yield and feed intake were measured in two experiments, the first with 30 cows grazing on pasture and the second with 16 cows fed indoors on fresh pasture. Feed intakes by the grazing cows were estimated from faecal outputs, using chronic oxide as the indigestible marker. The relation between daily metabolisable energy intake (MEI), daily milk energy output, liveweight 0.75 (LW0.75) and daily change in liveweight were examined by multiple regression analysis. Milk energy was significantly related to MEI, and therefore (at a common milk energy output) on feed conversion efficiency. An "index of efficiency" is proposed which will enable cows which differ in milk yield, weight and breed to be ranked accordingly to their predicted "gross feed conversion efficiency".}, issn = {1176-5283}, author = {Glassey CB and McPherson JR} } @conference {40513, title = {Oestrus, ovarian activity and embryo survival in ewes grazing high and low oestrogenic red clover}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {303-305}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Seasonal wool growth pattern, colour variation and associated wool characteristics were measured in a fleece weight selected (HFW) and its control (RC) flocks. Both flocks had a significant (p<0.01) decline in wool growth rate in winter compared with summer. The HFW advantage over RC averaged 19\% and 33\% for ewes, 24\% and 36\% for hoggets, in summer and winter respectively. Yield and fibre diameter patterns were closely associated with wool growth. There were no flock differences in either brightness or yellowness, however both Y and Z tritimulus values were lower in spring and summer while yellowness was higher in summer than other seasons. The results suggest that selection for HFW reduces the relative winter wool growth decline compared with RC.}, issn = {1176-5283}, author = {Anwar M and Keogh RG and McDonald MF} } @conference {40546, title = {Ovine IGF Antisense RNAs?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {449-454}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The mean interval from the end of synchrony treatment to the onset of oestrus can be highly variable and as a consequence {\textquoteright}single-time{\textquoteright} inseminations may occur at other than optimal times. This study was undertaken to identify some of the factors influencing the interval to oestrus following synchrony treatment, and to develop a spreadsheet model to assist with determining the timing of AI in ewes under a range of oestrous onset patterns. Synchrony device, PMSG, time of year, and live weight tended to have important effects on the interval to oestrus. Ewe genotype and year effects were generally small. Three new concepts have arisen from the modelling exercise. Firstly, the actual timing of AI to achieve near maximum fertility depends on the mean interval to oestrus in a given flock, but not the precision of synchrony or the incidence of ewes that are synchronised. Secondly, the {\textquoteright}tolerance{\textquoteright} about this optimum time of insemination depends on how much is known about the mean interval to onset (more information means more tolerance). Thirdly, the {\textquoteright}tolerance{\textquoteright} about this optimum time of insemination depends on the maximum reduction in flock pregnancy rate that is acceptable to the flock owner (higher reduction means more tolerance). If the onset pattern in a particular flock is unknown, the {\textquoteright}universal{\textquoteright} timing for a single fixed-time AI during the breeding season is 42- 46 h after CIDR}, issn = {1176-5283}, author = {Ord R and Ledgard A and Berg D and Peterson J} } @conference {40461, title = {Pasture protein and soluble carbohydrate levels in spring dairy pasture and associations with cow performance}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {83-86}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A survey on the East Coast of the North Island was conducted to provide information on the on-farm performance of drought tolerant pastures, including perceptions on animal toxicity problems. During October- December 1990 over 250 paddocks on 102 sheep/beef farms in Gisborne (23, Hawkes Bay (32) and the Wairarapa (47) were surveyed. Botanical composition was measured for each survey paddock from turf cores. No animal health problems were reported for prairie grass pastures, but farmers commented on improved animal performance from this pasture type. Animal health problems mentioned by farmers surveyed were: (1) ryegrass staggers, being reported for 58\% of survey farms and 9\% of survey paddocks. Ryegrass staggers was usually mentioned for paddocks with a high perennial ryegrass content (>40\% cores containing ryegrass). It was mentioned less frequently for mixed ryegrass- cocksfoot swards (>40\% ryegrass, >10\% cocksfoot) than for swards containing similar levels of ryegrass but little cocksfoot. (2) Bloat was mentioned more frequently for paddocks sown with tall fescue (15\%) than for other pasture types (3\%). Tall fescue swards had a higher clover content than ryegrass swards. (3) Stock ill-thrift (low growth rate) was mentioned for 6 of the 260 survey paddocks. The common feature of these paddocks was a moderate to high cocksfoot content (21- 72\% cores containing cocksfoot). (4) Phalaris toxicity was mentioned by 18\% of farmers who had phalaris pastures.}, issn = {1176-5283}, author = {Moller S and Matthew C and Wilson GF} } @conference {40539, title = {Plasma concentrations of progesterone and luteinizing hormone during CIDR device insertion and the oestrous cycle of fallow deer (Dama dama)}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {417-422}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Quantitative two-dimensional polyacrylamide gel electrophoresis has been used to search for variation among liver proteins in flocks of sheep which had been selected for either resistance or susceptibility to sporidesmin- induced liver damage. The goal was identification of proteins whose DNA sequences might be used to select animals for resistance to facial eczema. The quantitative gel techniques were used because of their ability to detect variability among many proteins in a single tissue sample. Differences in relative proportion were tested for 62 proteins among 5 ewes from each of the resistant and susceptible flocks. There were 7 proteins which showed statistically significant differences (P<0.05) between the flocks. When an analysis was made of changes in the relative proportions of proteins 2 days after experimental challenge of resistant flock ewes (n=8) with sporidesmin, 0.13 mg per kg body weight, 25 of 79 liver proteins showed significant change (P<0.05). This included partial loss of a 25 kDa, pI 5.7, protein which was also three times more abundant in undosed susceptible than undosed resistant females. These results are discussed in terms of the possible relationships between protein variation and the magnitude of toxic tissue damage. }, issn = {1176-5283}, author = {Morrow CJ and Asher GW and Smith JF and Veldhuizen FA} } @conference {40529, title = {Plasma prolactin in Romney sheep selected for hogget fleece weight}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {371-376}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Seventy nine mature, alpacas were scanned every 10-14 days using real time ultrasonography to visualise the foetus. There was a 24\% foetal loss between days 21-30 of gestation and parturition, with the maximum loss occurring between days 21-30 and days 31-40 of gestation. There was a 5\% loss of foetuses after day 100 of gestation.}, issn = {1176-5283}, author = {Clarke JN and Pearson AJ and Sumner RMW and Johnson DL and Dobbie JL and Wildermoth JE and Wrigglesworth AL} } @conference {40455, title = {The potential of industry by-products as supplementary feeds for dairy cows in the Hawkes Bay region}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {55-60}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied.}, issn = {1176-5283}, author = {Bramwell NF and Parker WJ and Gray DI and McCutcheon SN} } @conference {40532, title = {Prediction in animal production models based on the allometric hypothesis when the size variable is random}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {385-388}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Pleasants AB and Wake GC and Rae AL} } @conference {40442, title = {Presidential Address 1993 - The Management of Science}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {1-6}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Jersey cows in six mixed breed dairy herds produced up to $0.36 per cow per day less than their Friesian herd mates, during the 1991/92 dairy season. Jersey cows received lower Production Indexes (PI{\textquoteright}s) than their Friesian and Crossbred herd mates. It is not clear whether this lower production of Jersey{\textquoteright}s is a result of competition for feed between breed groups or is a genuine genetic difference between breeds. Some of the difference can be explained by the lower protein to fat ratio of Jersey milk compared to Friesian milk. Jersey cows are more efficient producers of milk income per kg liveweight than Friesians. If the breed composition of a herd is changing towards Friesians or Crossbred, then stocking rate as measured by liveweight per ha will also increase. Where stocking rate is already high this will inevitably reduce pasture intake of individual cows unless pasture supply is increased. Farmers would like to know if the Jersey component of their herds can be managed to improve production relative to Friesian or whether changes in breed composition of their herds are necessary to achieve optimum production and herd size in relation to feed supply and other farm resources.}, issn = {1176-5283}, author = {Wallace RD} } @conference {40463, title = {A prototype sire evaluation for New Zealand dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {91-94}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Growth of mammary epithelium is regulated by endocrine signals, local factors and sensitivity of epithelial cells to mitogens and inhibitors. This study was designed to identify how these factors interact in regulating mammogenesis and determine if breed differences exist among these factors. Mammary epithelial cell organoids were isolated from five pairs of beef and dairy heifers (7 to 9 months of age) and cultured within collagen gels. Sera were collected from all heifers and pooled within breed for use in culture. At slaughter, explants of mammary fat pad were also prepared for culture. Culture treatments were arranged in a 2x2x3x4 factorial design. Factors included source of cells (beef or dairy), addition of growth factors (10 ng/ml IGF-I + 50 ng/ml EGF or control), source of mammary fat pad explants (beef, dairy or none) and source of serum added to culture media at 5\% final concentration (beef, dairy, foetal calf serum, or none). Mammary growth was assessed as incorporation of [3H]thymidine into DNA. Mammary epithelial cells from beef heifers grew more rapidly than dairy cells (2518 vs 1192) cpm/ug; P<0.01). Growth of epithelia was enhanced by addition of growth factors (2265 vs 1445 cpm/ug; P<0.01). Sera from both beef and dairy heifers stimulated growth 2-fold compared to no serum (P<0.01), but addition of mammary fat inhibited epithelial growth (P<0.05). Cells from beef heifers were also more responsive to addition of serum and growth factors. These findings demonstrate that multiple factors interact to control mammary growth. Mammary fat pad of ruminants, unlike rodents, appears to inhibit epithelial growth.}, issn = {1176-5283}, author = {Garrick DJ and Harris BL and Shannon P and Sosa-Ferreyra C} } @conference {40443, title = {Rate of intake by sheep of different genotypes of subterranean clover in the vegetative growth stage}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {7-10}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Consulting Officer survey data from 198 owner/operator dairy farms for the 1991/92 season was analyzed. Trends in income, farm costs and profitability at changing levels of milkfat production/ha were examined. Increases in milkfat production/ha were associated with increases in stocking rate (R}, issn = {1176-5283}, author = {Dynes RA and Baker SK and Purser DB and Klein L and Wang XR} } @conference {40474, title = {Regulation of growth in cultured mammary epithelium from beef and dairy heifers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {143-146}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Red deer have recently been introduced to the intensive domestic environment, where there are many social and physical constraints not experienced by wild deer. Aspects of the social environment likely to affect welfare include group size, density and composition. Physical aspects of the pasture environment which may influence welfare are shade, shelter, wallows and opportunities for ranging behaviour, while variables in the handling environment which are probably important are pen construction and lighting. Various methods have been employed to assess welfare in red deer. Studies of confined deer have indicated that they respond to aversive conditions at pasture by pacing along fencelines, and in the handling environment by nosing doors and walls. Preference testing has compared different handling environments and treatments, and demonstrated that human presence, novelty and mechanical restraint were aversive. Results from detailed studies of velvet antler removal suggest that improved methods of providing analgesia are possible. Research into modifying the basic character of farmed deer through genetic selection or intensive handling of deer calves has been instigated. Overall, high welfare standards in deer production systems are a realistic goal. There are no long-established traditions to adhere to, and a foundation of productive assessment techniques and results has been established.}, issn = {1176-5283}, author = {McFadden TB and Cockrell DC} } @conference {40451, title = {The relationship between breeding index and conception rate and the cost of delayed conception}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {41-42}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Programmes for controlled calving and controlled breeding were evaluated with a group of large herds of dairy cows and heifers. The former procedure involved an injection of an analogue of prostaglandin F2a (PGF) at about Day 274 of gestation. Groups totalling 650 cows mainly calved in the following 4 days, with a peak between 36 to 60 h. The maximum calving rate was 138 cows within one 24 h period. Although calf survival rate was high (97\%) and the incidence of calving difficulties low (3\%), 14 cows were subsequently culled because of complications caused by retained foetal membranes. The controlled breeding programmes involved the use of CIDR-B devices for 8 days (cows) or 10 days (heifers) combined with a capsule containing 10 mg of oestradiol benzoate at device insertion (all cows and heifers), and with an injection of PGF at 6 days after insertion (cycling cows and all heifers), or an injection of equine chorionic gonadotrophin (eCG) at device removal (anoestrous cows). These systems were used with herds of 3009 and 500 heifers, as well as with 350, 400, 480 and 904 lactating cows. Every heifer was inseminated initially at about 48 h after device removal, but cows were inseminated on detection over 4 days. All inseminated animals were retreated with a previously used CIDR device to re-synchronise oestrus before a second insemination about 21 days later. A second re-synchrony was also applied with some cows before their third insemination. These programmes produced 4-day submission rates in the cows of 87\% to 95\% and 48 h synchrony rates of 94\% and 95\% in the heifers. The consequences of these programmes mean that about 90\% of animals in each herd will have conceived to AB or natural mating within 6 weeks. The rate of use of induced calving next season should be reduced to about 5\%. The increased concentration in calving is expected to reduce the incidence of treatments for anoestrum (from as high as 44\% in one of the herds) to about 10\%. Additional advantages include time saving, less labour, reduced labour stress, more cows and heifers to calf to AB sires, fewer bulls and earlier culling of bulls and empty cows. The maximum daily numbers were 904 CIDR devices inserted in 5 h, 504 heifers inseminated in 4 h and 689 cows inseminated in 5 h. Whereas calving and breeding had previously been major constraints in herd management, the use of these systems can realistically allow the herd size to be increased to more than 1000 cows. Many of the identified advantages will be equally applicable to herds of less than 200 cows.}, issn = {1176-5283}, author = {Wheadon MC} } @conference {40454, title = {The relationship between milkfat production per hectare and economic farm surplus on New Zealand dairy farms}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {51-54}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Dairy cows are in negative energy balance in the early postpartum period. It was hypothesised that cows that had not resumed ovulating by 1 week before the planned start of mating (PSM) were in negative energy for a longer period and/or to a greater depth than cycling cows. This case-control study compared the condition score, concentrations of selected blood metabolites and milk production in each of 90 pairs of anoestrous and cycling dairy cows on 8 farms. Anoestrous cows had a lower condition score (0.3 units), a higher urea concentration (0.3 mmol/l) and a lower glucose concentration (0.11 mmol/l) than their cycling pair. There was no difference in milk volume, milk fat, protein or length of lactation between cycling and anoestrous cows. The hypothesis that anoestrous cows are in lower energy balance than cycling cows is supported.}, issn = {1176-5283}, author = {Deane TH} } @conference {40446, title = {The relationship between staggers and diarrhoea in lambs grazing different components of endophyte-infected ryegrass}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {19-22}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Two experiments were carried out to measure the effects of fitting polyethylene body covers on the winter milk production of mature cows, and oxygen consumption by calves. In the first experiment, the covers had no significant effects on the winter milk production or liveweight of lactating cows grazing on pasture supplemented with silage. In the second experiment, oxygen consumption by young calves exposed to an air temperature of 9 C, 8 km/hour wind and simulated rain was significantly reduced by the wearing of covers (by 40\% during the period of rain). Covers offer an effective, low- cost method for reducing the adverse effect of cold wet weather on young calves reared out-of-doors.}, issn = {1176-5283}, author = {Pownall DB and Lucas RJ and Familton AS and Love BG and Hines SE and Fletcher LR} } @conference {40514, title = {Relationships between loose wool bulk and follicle and fibre characteristics in yearling Perendale sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {307-310}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Progeny test mating was carried out for 7 high fleece weight (HFW) and 5 random control (RC) sires from the Woodlands breeding flocks in 1987, and for a 4 HFW sires in 1988. In 1990, 8 of the surviving HFW sires were backcross mated to their daughters (born in 1987 and 1988). There was no evidence for any of these sires being heterozygous, or for any of the sires involved in the backcross being homozygous, for a major gene which affects either fleece weight or liveweight.}, issn = {1176-5283}, author = {Sumner RMW and Stobart RH and Johnson DL} } @conference {40535, title = {Relationships between objective and subjective measurements of carcass muscularity}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {397-402}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied }, issn = {1176-5283}, author = {Abdullah AY and Purchas RW and Davies AS and Kirton AH} } @conference {40495, title = {Repeatability estimates and selection flock effects for faecal nematode egg counts in Romney breeding ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {227-230}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The effect of melatonin (Regulin}, issn = {1176-5283}, author = {Morris CA and Watson TG and Baker RL and Hurford AP and Hosking BC} } @conference {40517, title = {Seasonal and between sheep differences in medullation of wool fibres}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {319-322}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Two experimental flocks of Romney sheep selected for increased hogget fleece weight show high selection responses (30-40\% of their controls) and evidence for altered seasonal patterns of annual wool growth, in line with published evidence from other flocks. While a preliminary experiment was unable to detect consistently significant line differences in plasma prolactin concentration at set time periods, there were indications of altered seasonal patterns in prolactin concentration and line differences in its association with wool growth. Both selection and control lines showed low prolactin concentrations in June and July (16 ng/ml). Concentrations rose in August, September and October, approximately doubling each month to an average level of 111 ng/ml in early November. Early results from this longitudinal study, still in progress, suggest that animals from the selected lines tended to maintain their low prolactin concentrations longer into the winter and early spring, and that this tendency is associated with a higher hogget fleece weight. By contrast, in the unselected control lines, high hogget fleece weight tended to be positively associated with increasing prolactin levels over the winter/early spring period.}, issn = {1176-5283}, author = {Scobie DR and Woods JL and Baird DB} } @conference {40520, title = {Seasonal fibre growth patterns in three breeds of down goat}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {331-334}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Subcutaneous fat colour at slaughter, after chilling for 24 hours was subjectively assessed on a scale of 1 (very white) to 5 hours (very yellow). Beef breeds (Angus, Beef Shorthorn, Galloway, Hereford and Red Poll), and dairy breeds (Friesian, Milking Shorthorn, Ayrshire and Jersey) of steer were slaughtered at 30 months of age over 5 consecutive years. The Friesian and Angus breeds were present every year and other breeds except for the Hereford and Red Poll were present for at least 2 years. The beef breeds had significantly (P<0.01) more carcasses with white fat than the dairy breeds. The Beef Shorthorn had significantly (P<0.05) more carcasses with white fat than the Angus. The Ayrshire had more carcasses with white fat (P<0.01) than the other dairy breeds. The Jersey had more carcasses (P<0.05) with yellow fat than all the other breeds. For the dairy breeds only there were significant correlations (0.4 - 0.7) between fat colour after chilling and the weight of kidney and channel fat. The more kidney and channel fat present the yellower the carcass. There was a correlation of 0.32 between meat colour and fat colour after slaughter. Friesian steers had more carcasses (P<0.01) with dark red meat than did the other breeds.}, issn = {1176-5283}, author = {O{\textquoteright}Neill KT and Litherland AJ and Spring PJ and Paterson DJ} } @conference {40541, title = {Selecting on pubertal traits to increase beef cow reproduction}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {427-432}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Two groups of 10 mature, crossbred cows received either a single daily dose of 10 g Mg or no supplemental Mg for two 5 day periods. Blood was sampled twice daily and urine once daily. On 3 days blood and urine were sampled four times. Serum Mg levels of 3 unsupplemented animals fell from 0.74 }, issn = {1176-5283}, author = {Morris CA and Bennett GL and Johnson DL} } @conference {40527, title = {Selection programmes for nematode resistant sheep in commercial flocks}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {359-362}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {An experiment was established at Waikeria, near Te Awamutu, to select for pubertal traits in Angus cattle, with selection first applied to the animals born in 1982. The aims of this paper are to report on genetic parameters for age at first oestrus (AFO) in heifers, weight at first oestrus (WFO) in heifers, scrotal circumference (SC), 13-month weight (W13) and calving day (CD), to compare the performance of young animals in the selection and control herds, and to assess prospects of achieving a correlated response in calving rate. Three selection herds and a control were set up, with single selection objectives being SC, AGE+ and AGE-, where {\textquoteright}+{\textquoteright} and {\textquoteright}-{\textquoteright} indicate selection for greater or lesser AFO. Phenotypic coefficients of variation were 15\% for AFO, 11\% for WFO, 8\% for SC, and 8\% for W13. Corresponding heritability estimates from Waikeria were 0.15, 0.30, 0.24 and 0.33, compared with those from other New Zealand research herds which averaged 0.34, 0.37, 0.38 and 0.36 respectively. The genetic correlation estimate for AFO and SC was - 0.81}, issn = {1176-5283}, author = {Watson TG and Hosking BC and Johnson DL and Hurford AP} } @conference {40530, title = {Serum concentrations of insulin-like growth factor-I during the oestrous cycle in ewes selected for lamb production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {377-380}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {In keeping with the evident requirement of insulin-like growth factor I (IGF-I) for normal growth in livestock, IGF-I is required for the normal proliferation of many non-transformed cells in tissue culture. The timing of IGF-I action is believed to be early in proliferation and/or prior to DNA synthesis. Since IGF-I acts on the Type I and Type II IGF receptors, and on the insulin receptor, it is possible that one or all of these receptors are proliferation regulated, such that they are expressed mainly at a certain stage(s) in the cell proliferation cycle. Regulation might occur at the level of the receptor or at the mRNA level. Several cell types have been chosen to test this model. In the experiments reported here, Norden Lab Feline Kidney (NLFK) cells were grown on coverslips and synchronised using a starve/feed regimen. Coverslips fixed at various times after refeeding were probed in situ for the presence of actin RNA and for IGF Type I receptor RNA. Whereas actin RNA levels increased and declined during the proliferation cycle in agreement with earlier reports. Type I receptor RNA levels were undetectable at the times sampled. Possible reasons for this are discussed.}, issn = {1176-5283}, author = {McFadden TB and Stellflug JA and Cockrell DC and Butler JE} } @conference {40460, title = {Short term changes in selected metabolites in pasture fed dairy cows during peak lactation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {77-82}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Computer-based decision support systems could provide an effective mechanism to facilitate technology transfer to farmers, and also improve the quality of their management decisions. The developers of computer systems, therefore, need to be cognisant of the constraints faced by farmers and the management methods that they use. To assist with the development of an expert system for the drying off decision a mail survey of 250 seasonal supply dairy farmers in five regions of New Zealand was undertaken during the 1992 winter to obtain information on management practices and decision aids used on farms. A response rate of 70\% was achieved. Most (69\%) farmers dried off some cows before drying off the main herd on the basis of age and condition. Final drying off date was most often based on pasture availability, cow conditions and/or the availability of supplements (85\%). Mean pasture cover targets at drying off ranged from 1606 kg DM/ha in Northland to 2129 kg DM/ha in South Taranaki. Most farmers expected pasture cover to increase between drying off and calving. Only 22\% of the farmers formally prepared a feed budget. A condition score target at drying off was given by 56\% of the respondents (of which only 40\% used a 1-10 scale). Computers were owned by 19\% of the surveyed farmers. Inexperience with computers (60\%), the cost of hardware (40\%), lack of time to learn how to use computers (34\%), no interest in computers (27\%) and the belief that computers could not help management (27\%) were cited as reasons for not owning a computer. The survey results indicate that computer-based decision support systems should be targeted initially at consultants who could provide a "bureau" type service to individual farmers. The present low level of formal feed budgeting limits the utility of decision-support systems that require objective farm data for developing grazing management recommendations.}, issn = {1176-5283}, author = {Kolver ES and Macmillan KL} } @conference {40519, title = {Skin follicle development in South African (SA) and SA x New Zealand Angora goats}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {327-330}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The expected value of the solution of the differential equation arising from the allometric hypothesis when the variables are random is found. This solution differs from the deterministic solution, so that predictions using the allometric equation which ignore the stochastic nature of the differential equation are biased. When lease squares estimation is carried out using the deterministic solution, ignoring the stochastic nature of the size variable, the estimate of the constant coefficient of the allometric equation may be severely biased. An example shows mild bias in estimates of the maturity parameter, but large bias in the estimate of the constant coefficient. To obtain unbiased estimates of the parameters in the allometric equation a factor equal to the reciprocal of the square of the size variable must be added to the usual log-log regression used to calculate estimates of the parameters. These results have application to models based on the allometric hypothesis, in particular models which are used in studies of carcass composition and the description of maintenance requirements in animal nutrition. When these models are used for prediction they need to be modified to account for any random variation occurring in the size variable.}, issn = {1176-5283}, author = {Parry AL and Death AF and Dick HB and Miller CM and Craven AJ} } @conference {40498, title = {Stability of invermectin resistance in a field strain of Ostergagia spp}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {239-242}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {This study was undertaken to investigate the effects of time from CIDR withdrawal and ewe age on conception rates in a sheep artificial insemination programme. Four groups each of 50 Romney ewes (balanced for ewe age, two-tooths vs mixed age) were synchronised by intravaginal insertion of CIDRs for 11 days. Ewes in each group were inseminated at 36h, 42h, 48h or 54h respectively from CIDR withdrawal by cervical insemination using 200 million sperm per insemination of fresh semen. Conception was determined by measuring non-return rates using harnessed rams. Conception rates increased (P<0.10) with the interval between CIDR withdrawal and fixed time insemination thus: 36h, 37\%; 42h, 49\%; 48h, 59\%; and 54h, 60\%. Conception rates were greater in mixed age ewes (58\%) than in two tooth ewes (43\%) (P<0.05). There was no interaction between the effects of age and time of insemination relative to CIDR withdrawal. It is concluded that there may be advantages in extending the interval between CIDR withdrawal and insemination to 48 to 54 h as opposed to the current industry recommendations of 45 to 48 hours.}, issn = {1176-5283}, author = {Watson TG and Hosking BC and McKee PF} } @conference {40540, title = {Studies of alternative selection policies for the New Zealand sport horse}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {423-426}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The fate of mineral solutions when drenched was assessed in cows slaughtered after drenching using a dye visible in gut contents. Seven groups of 10 cows were drenched with water or solutions of magnesium oxide, magnesium chloride, magnesium sulphate, sodium chloride, sodium bicarbonate or zinc oxide in Trial 1. Frequency of closure was higher (P<0.05) for sodium bicarbonate (60\%) than for magnesium oxide or magnesium chloride (10 to 20\%). Five cows drenched with water alone showed bypass of the rumen. In Trial 2 four groups of 6 or 7 cows were drenched with water or solutions containing selenium. Hydromin or copper sulphate. Frequency of closure was higher (P<0.05) for copper sulphate (70\%) than for water or selenium (0\%). The results suggest that bypass of the rumen in response to drenching may contribute to apparent failures of bloat drenches, particularly when certain minerals are added to the drench. }, issn = {1176-5283}, author = {Rogers CW and Wickham GA} } @conference {40515, title = {Textile Evaluation of Texel Wools}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {311-314}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Evidence for multiple anthelmintic resistance has emerged rapidly. The need to investigate innovative alternatives to maximise nematode control is significantly more critical. Selection of sheep with above average natural or acquired resistance to infection is one such option that is being studied. Progeny testing for faecal nematode egg count (FEC) has been evaluated following natural infection. Research involving 104 sires used on 4 commercial Romney studies over the last 2-5 years demonstrated considerable genetic variation. Heritability estimates for FEC ranged from 0.17 to 0.27. Moderate to strong positive genetic correlations (0.38-0.75) between FEC1 and FEC2 were observed. Furthermore, genetic correlations between FEC1 or FEC2 and production traits, including weaning weight, later liveweights and fleece weight were moderate. Breeders face a philosophical dilemma whether to become involved in selection for nematode resistance or not in the face of the many unanswered questions, including why and how to undertake the work. Results to date indicate that breeders can adopt and apply a screening protocol to add to breeding trait records.}, issn = {1176-5283}, author = {Maddever DC and Wuliji T} } @conference {40504, title = {Twinning in beef cows: preliminary results from embryo transfer studies}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {263-266}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {While the main focus in the breeding of Texel sheep in New Zealand has been selection for superior meat production there are significant qualities in the wool which make it a highly desirable fibre. Texel, Texel X Romney and Romney wools are evaluated to determine their relative attributes as textile fibres in wool products where good length and high bulk are considered important. Evaluation involved examining the value of good length bulk wool in the current wool market, spinning semi-worsted yarns, manufacturing carpets and sample bedding products. All three lines performed as expected from the measured fibre characteristics. Core bulk of the scoured wool for Texel, Texel X Romney and the Romney were respectively 32.9 cm3/g, 29 cm3/g and 25.7 cm3/g. Based on an average market value of 450 c/kg clean and 1991/92 relativities, the premium for bulk of these long good colour wools is 10 c/kg/unit. The high bulk wools gave improved spinning performance 44.4 52.9 and 73.3 end breaks per 100 spindle hours at 5000-6000 rpm for the Texel, Texel X Romney and Romney lines respectively. Improved abrasion resistance of carpet made from the Texel and Texel-cross was attributable to different pile weight and yarn bulk values. Samples evaluated indicate Texel sheep produce wools with similar textile properties to New Zealand crossbred wools but with higher bulk. The Texel breed should be monitored for its suitability as a source of genetic material to increase bulk in New Zealand wools. Lack of quantitative knowledge of the change in fleece weight and carcass returns from the introduction of the Texel genetic influence into Romney stock prevents assessment of their economic benefit to the New Zealand farmer.}, issn = {1176-5283}, author = {McMillan WH and Hall DRH and Evans PH and Day AM} } @conference {40489, title = {Twin-suckling beef cows using foster calves: effects on cow and calf performance}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {203-205}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {One hundred and twenty three Friesian or Friesian x Jersey mature dairy cows were used to examine the effects of Rumensin Anti- bloat Capsules (ABC), containing sodium monesin on plasma magnesium, glucose and }, issn = {1176-5283}, author = {McMillan WH and Evans PH and Hall DRH and McLean M} } @conference {40534, title = {The use of commercial grading probes for classifying lamb carcasses}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {393-396}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {North American wapiti (Cervus elaphus sub species)_ evolved within, and inhabit, an extremely varied environment generally not apparent within any pastoral farm environment. Normal farm management practices also reduce disease and predation; modify or prevent behavioral strategies such as migration, wallowing and isolation at calving; impose artificial mate selection; result in the removal of antlers in velvet, and premature dissociation of familial groups. Whilst the object of these practices is to utilise deer for animal production, primarily meat and velvet antler, the vast changes imposed will undoubtedly result in rapid changes in genetic, physiological, morphological and behavioral characteristics of the animals. Deer provide a unique opportunity to study and manipulate the effects of farming in a large ruminant, but at the same time the ecological requirements of the animal should be considered.}, issn = {1176-5283}, author = {Kirton AH and Mercer GJK and Duganzich DM and Uljee AE} } @conference {40459, title = {Utilisation of white clover pasture and maize silage by the lactating dairy cow}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {73-76}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A survey of 110 beef cattle farmers within Waitomo Country was used to identify the main farm and farmer factors associated with adoption of three beef cow technologies. It was found that 48\% of farmers had adopted mating of heifers to calve at two years of age; 43\% had adopted breeding from dairy beef crossbred cows; and 60\% were using terminal beef breeding bulls. Overall, 30\% of the farmers had adopted none of the technologies; 20\% had adopted one of the technologies; 25\% had adopted all three of the technologies. The levels of adoption were higher than those expected from national statistics. An assessment was made of the relationship of demographic indicators with technology adoption. Farmers{\textquoteright} age, education and sources of information were associated with technology uptake. A number of business indicators were included in the survey. Gross farm income, farm expenditure, stocking rate, paddock number, stock weighing, were found to be associated with adoption of at least one of the technologies. The beliefs that farmers had about their core enterprise - beef breeding cows, was found to be closely associated with their adoption decisions. It is shown that evaluation of new technologies in relation to the core enterprise beliefs held by individual farmers should be included when considering research programmes of potential value to the industry.}, issn = {1176-5283}, author = {Wanjaiya GW and Wales WJ and Dellow DW} } @conference {40516, title = {Variability in the susceptibility of wool to yellowing}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {315-318}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The advent of highly polymorphic genetic markers in sheep has enabled, for the first time, a retrospective study of the pedigree records of New Zealand sheep flocks. Three research flocks and one study flock have been analysed. The flocks were genotyped using a variety of microsatellite DNA markers and/or the polymorphic blood proteins transferrin, vitamin D binding protein, and ovine plasminogen antigen. The first flocks analysed were the half-sib Booroola pedigrees from progeny tests of heterozygous Booroola rams and their daughters. Of 291 daughters of rams, 7 were shown to have an incorrect sire assignment. The remaining flocks consisted of full sire/dam/offspring pedigrees. The stud flock showed 2 instances in 45 pedigrees where the sire was incorrectly assigned. Of 53 Inverdale lambs tested 5 were shown to have an incorrectly assigned parent and in 387 pedigrees from a progeny test flock at Woodlands only two pedigree errors were detected. These error rates are lower than previously estimated from field observations which give confidence in the use of these pedigrees for genetic selection. Simple flock management techniques are described which help achieve the low error rates reported.}, issn = {1176-5283}, author = {Reid TC} } @conference {40473, title = {Vasodilatory properties of parathyroid hormone-related protein in the mammary gland of the lactating goat}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {139-142}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {New Zealand dairy systems are characterised by extensively- managed outdoor herds which calve in spring. Such systems allow cattle to perform a wider range of normal behaviours than is possible in more intensive conditions. However, there are aspects of extensive management which may compromise the welfare of dairy cattle. These include practices which are intrinsic to the management system and strategic interventions. This paper will discuss some of the issues pertaining to the welfare of dairy cattle, the methods by which welfare is assessed and attitudes within the local and international community regarding the management of dairy cattle in New Zealand.}, issn = {1176-5283}, author = {Prosser CG and Davis SR and Farr VC} } @conference {40484, title = {Is the welfare of dairy cows at risk from current farm practices?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {179-182}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A selection experiment to breed for high (H), control (C) or low (L) faecal egg count (FEC) levels in weaned Romney lambs was established in 1985, being maintained at Rotomahana (until weaning 1988) and at Tokanui thereafter. In winter 1990, pregnant ewes (aged 2 to 6 years) were drafted into grazing groups according to expected lambing date ({\textquoteright}early{\textquoteright} and {\textquoteright}late{\textquoteright} ewes), in order to study periparturient FEC. Non- pregnant ewes and unmated yearling females were also recorded. Faecal samples for FEC were taken from all females (n=253) before and after the pregnant ewes lambed (median lambing dates for early and late ewes being 19 August and 31 August), and then in October and in November. Lambs were also faecal sampled at 3-month weaning. A mixed model was fitted to log e (FEC + 100), with fixed effects for selection flock, group (early ewes, late ewes, non- pregnant ewes, yearlings), sample day and the interaction of group and day, and with {\textquoteright}animal{\textquoteright} as a random effect. The repeatability was 0.50 }, issn = {1176-5283}, author = {Hargreaves AL and Matthews LR and Verkerk GA} } @conference {40492, title = {The welfare status of egg-production in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {215-217}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {During the springs of 1990 and 1991 128 recipient cows were artificially inseminated (AI) and 7 days later one embryo was transferred (ET) to induce twinning. Twenty-six per cent (33/128) of recipients returned to oestrus within 25 days of AI. Pregnancy diagnosis at 35 days indicated 12\%, 39\% and 23\% of recipients with 0, 1 or 2 foetuses. The expected calving rate was 63\% of which 38\% were expected to twin. Only 43\% calved but 50\% gave birth to twins. The results were similar in both years. These results indicate that the combination of AI and ET result in normal pregnancy rates and higher than expected twin pregnancy rates at about five weeks after AI. However, losses from five weeks to calving are several times higher than expected, and are a major limitation to the achievement of 100\% plus calving to one round of treatment. Early pregnancy diagnosis (day 35) may have precipitated such losses.}, issn = {1176-5283}, author = {Temple W and Foster TM} } @conference {40548, title = {What might be the consequences of adapting wild animals, such as wapiti, to a farm environment?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {457-460}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Fisher MW and Bryant LD} } @conference {40518, title = {Wool growth responses of Romney rams selected for high or low wool strength to nutrient supplementation in winter}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {323-326}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Treatment of sheep, mice and humans with exogenous recombinantly- derived insulin-like growth factor-1 (IGF-1) has been reported to produce a hyperglycaemic state. In mice this is associated with the abolition of maternal constraint during pregnancy. Exogenous IGF-1 also alters renal clearance in sheep and humans, decreasing circulating concentrations of urea and creatinine. The objective of this study was to determine whether similar changes are apparent in sheep divergently selected for plasma IGF-1 concentrations. Ewe hoggets (10 months old), 16 each from the Massey University Low (L), Control (C) and High (H) IGF-1 selection lines, were blood sampled by jugular venipuncture over a 5 hour period after removal from pasture. Plasma metabolite concentrations were assayed and adjusted for the effects of sampling time relative to removal from pasture. There were no differences between the line (L vs C vs H) in plasma concentrations of urea (7.34 vs 7.35 vs 7.32 mM, Pooled SE = 0.25 mM) and, although there was a significant line effect for creatinine (P<0.05), none of the between-line comparisons was significant (0.073 vs 0.075 vs 0.075 mM, Pooled Se = 0.002 mM). However, glucose concentrations were greatest in the H line (3.72 mM), followed by the C line (3.56 mM) and the L line (3.45 mM) (PSE = 0.07 mM, P<0.05). Whereas glucose and urea concentrations declined with time off pasture in the H line (b = -0.133 }, issn = {1176-5283}, author = {Bray AR and Smith MC and Merrick NC} } @conference {40409, title = {Advancing calving in red deer: The effects on growth and sexual development}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {187-190}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Thirty ewe lambs each of Merino, Romney, feral (of Merino origin) and Wiltshire breeds were evaluated for dag score, flystrike and nematode resistance. The lambs were born in August 1990 with the feral lambs around one month younger. The lambs were transported to Flock House and shorn and grazed together from the 21 January 1991 until 1 June 1991. There was no difference in the geometric mean of faecal egg counts between the different breeds (p=0.11). Lambs were fly struck from February to May with 33\%, 10\%, 10\% of Merinos, Romneys and Wiltshires being attached. No feral lambs were fly struck. Most flystrike was caused by the Australian green blowfly (Lucila cuprina). The Wiltshire breed had the lowest dag score while the feral sheep had a dag score consistently lower than the Romney and Merino breeds (p<0.001). The wet weight of dag clipped at the end of the experiment was 4 }, issn = {1176-5283}, author = {Meikle LM and Fennessy PF and Fisher MW and Patene HJ} } @conference {40386, title = {Angora goat production from different legumes mixed with ryegrass}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {97-100}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Analyses of live weights at birth, weaning (4 months of age) and at the yearling stage from 360 fallow deer born in 19887 to 1990 were carried out to examine non-genetic effects and to provide preliminary estimates of heritability and genetic correlations. Weights of breeding does were also analysed. Fifteen sires (17 mating groups) were involved, with 2 sires repeated across years. After adjustment for fixed effects, coefficients of phenotypic variation were 10.5, 8.2 and 5.7\% respectively for the three weights. The range of birth dates within year, excluding 3 outliers, averaged 36 days (s.d. 7.9 days). The differences in weight between males and females were 0.27, 2.5 and 9.3 kg at birth, weaning and the yearling stage. Regressions of live weights on birth date were zero, -0.15 }, issn = {1176-5283}, author = {Stevens DR and Casey MJ and Lucas RJ and Baxter GS and Miller KB} } @conference {40380, title = {The behaviour and welfare of calves during unloading after transportation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {73-76}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Computers traditionally make their first appearance in a business as a tool to automate time consuming tasks such as accounting, inventory control and document preparation. However, the true value of a computer system often lies in its ability to provide timely summaries and analyses of business performance. Business information requirements can be broadly categorised into three areas: operational processing (day to day tasks, data capture), management information (reporting and tracking, tactical planning) and decision support (strategic planning). Depending on the software used, a computer system can provide information from any of these areas. However, it is unlikely that any single software package can meet all the information needs of a business. It is becoming increasingly important for data to be easily transferred between systems. This paper looks at the various types of software available, what kinds of information each can provide and the need for integration between packages to provide the "total picture". }, issn = {1176-5283}, author = {Bremner KJ and Matthews LR and Brears DJ and Painting AM} } @conference {40441, title = {A bibliographic database on the biology of the sheep and goat - Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {313-314}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Interest in gathering physical data on individual farms has escalated in recent years with the establishment of a number of focal farm schemes throughout the country. These schemes are aimed at identifying constraints to farm production at a local level, and then demonstrating techniques to overcome these constraints and hence increase production accordingly. This paper reviews the Northland Focal Farm Scheme and shows that this process of technology uptake by farmers outside such a monitoring scheme is slow to occur. Farmer confidence and other personal factors appear to be major limitations to management change and increased production on many farms.}, issn = {1176-5283}, author = {Davies AS} } @conference {40367, title = {Blood metabolites near calving in twin-pregnant and single- pregnant cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {21-24}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {This trial was designed to test the hypothesis that increased faecal egg counts (FEC) of fleeceweight-selected (FW) lambs over control (C) lambs represented a decreased resistance to internal parasitism in FW lambs. Measurements were recorded over a 42 day period from late February 1991 using August-born lambs from the Massey University FW and C flocks. All lambs were drenched with ivermectin on day 0. Lambs of each sex and flock were randomly allocated within sire (4 per flock) to receive an albendazole controlled release capsule (+ALB). Ewes and rams were run separately. Midside wool growth, liveweight, and FEC were recorded, and estimates of dry matter intake were inferred from chromate analyses. The FW lambs had consistently higher FEC{\textquoteright}s than C lambs. Significant differences were observed by flock and ALB treatment in both wool production and liveweight gain, but no significant flock-by-ALB interaction were detected. Trends in production traits indicated that the superiority of FW lambs may have increased in situations where the development of adult worm burdens was continually suppressed. However, no clear evidence was found to show that FEC is a reliable indicator of a sheep{\textquoteright}s resistance to production losses arising out of internal parasitism. }, issn = {1176-5283}, author = {Morris CA and Day AM and Jones KR} } @conference {40379, title = {Breed variation in expression of faecal nematode egg count - A Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {69-72}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Five two-tooth Coopworth ewes were used to monitor the effects of changing caecal pH on magnesium (Mg) solubility and absorption pH change was induced by infusion of volatile fatty acid (VFA) (0, 220, 440, 660, 880 mmol; ration 0.80:0.15:0.05 acetic:propionic:butyric in 2016 ml of deionised water) into the terminal ileum for 24 h. Treatments were randomly applied to each animal using a latin square design. During the infusion samples of blood and urine were taken at 4 h intervals and proximal colonic digesta at 4, 16 and 24 h. Apparent Mg absorption from the large intestine was estimated from changes in plasma Mg concentration and urinary Mg excretion. Sixteen hours after the commencement of infusion digesta pH decreased and Mg solubility increased. For example, with the 880 mmol infusion digesta pH had decreased by 2.1 }, issn = {1176-5283}, author = {Watson TG and Hosking BC and Hurford AP} } @conference {40408, title = {The breeding season of pubertal red deer hinds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {183-186}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {This paper summarises a series of experiments near Rotorua in which the liveweight changes of sheep grazed on pasture under Pinus Radiata was measured. In general terms sheep performance was lower as the tree stocking increased. Long term experiments have shown that under continuous grazing, sheep performance declines with increased tree stocking from as early as tree age 5 years. Feed allowance experiments indicated there may be a general decline in the feed value of pasture growing under Pinus Radiata. The effects were minor at tree stockings up to 100 stems per hectare. The effects would be minimised by offering higher allowances, to provide greater feed selection for the stock. }, issn = {1176-5283}, author = {Duckworth JA and Barrell GK} } @conference {40437, title = {Cell proliferation during fibre growth initiation in ferret hair follicles}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {299-302}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {intake and liveweight change of 7-month hoggets was measured when ad lib grazing steep hill pastures containing 10, 40 and 50\% dead matter above 2 cm, in autumn. Two groups of 24 sheep from a "biological" and a "conventional" farming system were used in the trial. Digestible organic matter intake/kg liveweight and liveweight change were affected by dead matter content (P<0.05) but were similar for biological and conventional hoggets (P>0.1) despite high faecal egg counts in biological sheep. Better performance on high quality pasture was attributed to a higher organic matter digestibility and lower dead matter content in the diet, possibly due to the greater accessibility of green matter in the grazed horizons.}, issn = {1176-5283}, author = {Saywell DP and Nixon AJ} } @conference {40418, title = {Comparative performance of ewes shorn either once-yearly or 3 times in 2 years}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {225-228}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The determinants of wool production per unit area of skin are reviewed, and found to be dominated by follicle volume. Evidence is presented to show that follicle cells destined to become fibre cells differentiate into a continuum of cell types rather than discrete populations of medullary, ortho- and paracortical cells as the literature suggests. Fibres of the same dimensions grown by a sheep at one point in time contain differing proportions of these cell types. It is hypothesised that there is a degree of independence between fibre volume and cell differentiation. Medulla formation is explained in terms of competition between follicles for keratin precursors, so that fibre volume exceeds the available volume of keratin. A similar mechanism is proposed for the cortex, where paracortex and mesocortex become less prevalent as total fibre volume increases. It is concluded that a model for fibre formation can be considered in two parts: one which generates fibre volume and another which determines cell type within that volume. }, issn = {1176-5283}, author = {Sumner RMW and Webby RW and Winter RD} } @conference {40372, title = {A comparison between subjective and objective (carcass weight plus GR or the Hennessy Grading Probe) methods for classifying lamb carcasses}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {41-44}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Stress research in farm animals is becoming increasingly important as a result of public concern for the welfare of animals and the ongoing need to increase the efficiency of animal production. Changes in the behaviour of animals is often the first indicator that a particular farming practice may be aversive or stressful. For example, cattle housed indoors on concrete floors have fewer resting bouts than those on deep litter or at pasture. Subsequent measurement of a variety of physiological parameters confirmed that lying down on slatted floors is stressful. Changes were noted in the episodic secretory pattern of glucocorticosterioid hormone, in the cortisol response to challenge with a standard dose of ACTH (1-24) and in heart rate. Ongoing studies with dairy cattle indicate that the frequencies and types of fly-avoidance behaviours utilised by animals without tails differ from those with tails. In addition, animals without tails have a higher number of flies on the body. Physiological parameters will be monitored to determine if the decreased ability of cattle without tails to remove flies results in altered physiological responses indicative of stress. These studies show that a multi-disciplinary approach is required to quantify the relative stressfulness of various farming practices. }, issn = {1176-5283}, author = {Kirton AH and Mercer GJK and Duganzich DM} } @conference {40385, title = {A comparison of grain and pasture finishing of heavyweight cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {93-96}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Data for the years 1986 to 1990 from the "Kamo" out-of-season lambing flock were subjected to analyses to determine the genetic variation for lambing date. The response variate was date of lambing (provided the ewe had a chance to mate for an autumn lambing) and this was transformed to an underlying normal scale by treating it as an ordered categorical response. Restricted maximum likelihood (REML) analyses were performed using an animal model. Year of record and age of ewe were included as fixed effects. There were 870 ewes having a total of 1967 lambing records. The estimate of heritability for standardised lambing data was 0.23 and repeatability 0.36 while the heritability for litter size was 0.03. Preliminary multivariate analysis indicated that the genetic correlation between standardised lambing date and litter size to be 0.09. At the time of disbanding of the flock samples of ewes selected on the phenotypic response (i.e. number of times lambed in autumn) of the ewe or of her dam, were brought to Ruakura. In 1991 following a best linear unbiased prediction (BLUP) analyses these were assigned to Autumn and Spring lambing flocks on the basis of their breeding value (BV) for standardised date of lambing. The average BV for the Autumn flock was - 0.13 while that for spring was +0.07 and there was a 26 day difference in mean lambing date (167 vs 193). }, issn = {1176-5283}, author = {Muir PD and Cruickshank GJ and Smith NB and MacLean KS and Wallace GJ} } @conference {40415, title = {Comparison of growth, hogget fleece weight and reproductive traits of three sheep breeds from a flock selected for prolificacy and a Romney control flock}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {211-216}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The total glucose concentration of a medium changes with the extent of serum supplementation, and this may have an effect on embryonic development in vitro. In this study, 1- and 2-cell sheep embryos (N+109) were cultured for approximately 120 hours at 39 C under humidified 5\% CO2, 5\%)2 and 90\% N2 in Synthetic Oviduct Fluid medium (SOF) supplemented with 20\% human serum and a total glucose concentration of either 1.5 mM (modified-SOF) or 2.3 mM (unmodified-SOF). A slight effect was observed on the proportion of embryos developing to at least the expanded blastocyst stage (63\% and 48\% for modified-SOF and unmodified-SOF, respectively, P<0.1). Twenty-eight blastocysts from each treatment were selected and transferred to 28 synchronised, mature ewes (2 blastocysts per ewe). Pregnancy and number of foetuses were determined by ultrasonography 54 days after transfer. All ewes were pregnant and survival of embryos was 82\% and 71\% for modified-SOF and SOF, respectively. However, a high post-natal mortality rate was observed (37\%), which was mostly attributed to a relatively high birthweight of dead lambs (6.4 }, issn = {1176-5283}, author = {McEwan JC and Davis GH and Dodds KG and Fennessy PF and Clarke JN and Bruce GD and Hishon MG} } @conference {40376, title = {A comparison of internal parasitism in fleeceweight-selected and control Romney sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {57-60}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Rising three year old Angus steers were fed on either ryegrass/subterranean clover pasture or a high grain ration (70\% maize grain/ 30\% pasture silage) for an adjustment period of 2 weeks and an experimental period of 12 weeks. Then cattle were slaughtered initially and 10 cattle from each treatment group were slaughtered after 6, 10 and 14 weeks. Cattle offered the high grain ration had feed intakes of up to 2.7\% of bodyweight and over the 12 weeks experimental period average liveweight gains of 1.4 and 2.0 kg/d were achieved in the pasture and grain fed groups, respectively. Carcass weight increased from 316 kg to 363 kg in the pasture group and 406 kg in the grain fed group at final slaughter. Intramuscular (chemical) fat at the 12th rib increased from 13\% to 23\% and was not affected by diet. Levels of intramuscular fat were up to 38\% and were similar to those reported for Japanese Wagyu beef. Lean meat colour was significantly brighter (P<0.001) as a result of grain feeding and the incidence of yellow fat was reduced. }, issn = {1176-5283}, author = {Howse SW and Blair HT and Garrick DJ and Pomroy WE} } @conference {40389, title = {Computer Applications: Meeting the information needs of a business}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {107-110}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Direct selection for 13-month live weight in NZ Angus cattle for 15 years has resulted in 17\% heavier yearlings and 12\% heavier adults when compared with unselected control animals. The mean daily food intake of growth-selected bulls is higher on a per head basis but is similar when adjusted for differences in live weight. The objective of this paper is to model the efficiency of a breeding cow herd, including replacements, derived from selected and control lines. The index of efficiency used is weight of calf weaned per unit weight of winter feed required. Published performance data from the 2 herds are used to quantify calf output and feed requirements are based on published growth patterns in the 2 herds. Our analyses show that, for the same winter feed requirement, the selected herd when compared with the control herd would have: 88 vs 100 cows wintered; 65 vs 72 calves weaned, and mean calf weaning weight would be 174 vs 158 kg per head. Efficiency was estimated to be 99.8 vs 100 units. Theses results indicate that while selection for yearling weight has resulted in heavier calves and breeding cows, the calculated extra winter feed costs associated with the heavier selected herd makes them no more efficient than the randomly bred control herd. For the selected herd to be more efficient, either a reproductive advantage well in excess of the 3 percent point advantage achieved would be required, or the metabolic efficiency of the selected cows would need to increase. In economic terms, the selected herd may be more efficient than the control herd for 2 reasons. Firstly, since herd size is lower, total herd costs are likely to be lower. Secondly, if a premium exists for heavier calves, the calves from the selected herd are likely to be worth more per head. }, issn = {1176-5283}, author = {Abell W} } @conference {40392, title = {Computer use on my farm}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {119-120}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The objective of the experiments was to test the hypothesis that pretreatment with progesterone would increase the proportion of animals exhibiting behavioural oestrus following injection of oestradiol-17}, issn = {1176-5283}, author = {Harris PR} } @conference {40366, title = {Concentrations of oestrone sulphate in milk during pregnancy in dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {17-20}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Host resistance to internal parasites, as measured by faecal egg count and dagginess was investigated in ram lambs born in the 1981-83 years (approximately generation 3) from the Woodlands selection lines. Lines were selected for either: number of lambs born, 100 day weight, hogget fleece weight and a production index in which all three traits are combined; a fifth line was a randomly selected control. Ram lambs were drenched with anthelmintic and then exposed to contaminated pasture for a period of 6-7 weeks and then faecal sampled. Total plasma protein, albumin and pepsinogen were measured. The results demonstrated significant variation between selection lines in faecal egg count, dag score, liveweight gain, wool growth and blood plasma parameters. Between selection lines, faecal egg count was positively correlated with liveweight gain (0.95) and wool growth (0.41). Blood pepsinogen and total blood protein were both negatively associated with faecal egg count and liveweight gain (correlations of -0.51 to -0.90). Using sire variation within selection line (progeny of 65 sires) produced heritability estimates of 0.13 }, issn = {1176-5283}, author = {Henderson KM and Karanikolas M and Kenealy L and Macmillan KL} } @conference {40364, title = {A conceptual framework for an expert system to improve drying off decisions on seasonal supply dairy farms - Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {11-12}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Forty Border Leicester (BL) and forty-eight Dorset Down (DD) ewe hoggets (7.5mo) that had been farmed together were scanned using a real-time ultrasound machine, at six sites with one muscle depth (B) and five subcutaneous fat depth measurements (R - tissue depth over fifth rib, C - backfat over last rib, GR, L - backfat over last lumbar vertebrae, T - fat over tail) being taken. Comparisons of tissue ratios (individual fat depth divided by B) were used to characterise subcutaneous fat distribution. From these ratios it was found that the DD had 9\%, 10\% and 6\% greater ratios at R, L and T respectively, and 7\% lower ratios at C and GR. Breed differences at R, GR and T were significant (P<0.05). It was concluded that true genetic differences in subcutaneous fat distribution existed between the genotypes studied. These findings have implications for carcass classification, for breeding programmes for lean growth, and for comparisons of the fatness of different genotypes. }, issn = {1176-5283}, author = {Gray DI and Lynch GA and Lockhart JC and Parker WJ and Todd EG and Brookes IM} } @conference {40362, title = {Dairy Production in developing countries}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {3-6}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Measurement accuracy for ultrasonic tissue depths was examined in order to determine the relative importance of factors affecting it. Repeatabilities for ultrasonic fat depth (UFD) and ultrasonic muscle depth (UMD) were assessed from repeated runs (2) in three groups of animals; Dorset Down ewes (LW=45.4kg, 7.5mo, n=50), Coopworth rams (LW=51.5kg, 11mo, n-50) and Dorset Down rams (LW=38kg, 4.5mo, n=50). Repeatability values were higher for UMD (0.77, 0.95 \& 0.87 for the 3 groups, respectively) than for UFD (0.63, 0.84 \& 0.82, respectively). Lower repeatabilities were due to high within-animal variance rather than low between-animal variance. Measurements made on videotaped images demonstrated that image registration had a great effect on repeatability, with image interpretation having a negligible effect. A comparison of two operators differing in experience showed that fat depth was measured equally accurately by both operators but that the experienced operator measured muscle depth more accurately. It was concluded that tissue depths can be accurately assessed from one measurement. }, issn = {1176-5283}, author = {McDowell RE} } @conference {40377, title = {Developments in breeding Perendale sheep for resistance or susceptibility to internal nematode parasites}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {61-64}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The liveweight gain, carrying capacity and total animal production from different pastures grazed by year old angora type wether goats were assessed during the spring, summer and autumn of two years. {\textquoteright}Grasslands Nui{\textquoteright} perennial ryegrass (Lolium perenne L.) was sown with {\textquoteright}Grasslands Tahora{\textquoteright} white clover (Trifolium repens L.), {\textquoteright}Grasslands Pawera{\textquoteright} red clover (Trifolium pratense L.), or {\textquoteright}Grasslands Maku{\textquoteright} lotus (Lotus pendunculatus Cav.) in December 1988 and measurements began in September 1989. Goat liveweight gain in spring was similar on all treatments averaging 130g/hd/day. Summer liveweight gain on red clover was 76g/hd/day, greater than the average of 56g/hd/day for white clover and lotus pastures. Autumn liveweight gains were not significantly different averaging 44g/hd/day. Carrying capacity was lowest on lotus pastures in all seasons. White clover pastures had the highest carrying capacity in all seasons though only significantly greater than red clover in autumn. No differences in total animal production per hectare were found in spring. Red clover, however, had 45\% more animal production in summer than white clover or lotus pastures. This increased production was attributed to a greater consumption of legume due to both the dominance of red clover in the upper sward horizons and an active selection of red clover by the goats. }, issn = {1176-5283}, author = {Watson TG and Hosking BC and Hurford AP and Mather BC} } @conference {40401, title = {Dose-response to a single injection of PMSG in Merino ewes carrying a double copy of the Booroola FecB gene}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {153-156}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Sheep shorn with a cover-comb were compared with conventionally shorn sheep in two experiments. In the first experiment, ewe and lamb performance and some aspects of ewe physiology were measured with 60 Romney ewes which were shorn before lambing. In the second experiment, oxygen consumption by 12 Romney hoggets was measured before and after shearing in calorimeters at 10 C. In the first experiment, herbage intake by ewes in the 3 weeks post- shearing was not affected by shearing method. There were no treatment effects on the liveweight of ewes, birthweight and growth rate of lambs nor on ewe wool production during the 2 months post-shearing. However, on days 1 and 3 after shearing the plasma concentrations of non- esterified fatty acids and of 3- hydroxybutyrate were higher in the ewes shorn with the conventional comb than in those shorn with the cover comb. In the second experiment oxygen consumption was increased immediately after shearing, by 47\% and 25\% in the conventional- and cover-comb sheep respectively. The difference between the two groups, which remained significant until day 12 post-shearing, decreased with time until it disappeared on day 22. The results show that sheep shorn with the cover-comb were significantly more resistant to cold conditions than those shorn with the conventional comb, particularly during the 3 days post-shearing. Use of the cover comb may offer a useful low cost method of reducing the effects of cold conditions after shearing, but its effects on mortality have not been demonstrated. }, issn = {1176-5283}, author = {Shackell GH and Isaacs KL} } @conference {40423, title = {The effect of condensed tannin containing diets on whole body amino acid utilisation in Romney sheep: consequences for wool growth}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {243-246}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Fleece production, fibre characteristics and spring liveweight in adult alpaca, tui and cria farmed in the South Island are reported. The shearing and fibre classing techniques are also described. Liveweight at shearing was 63.9kg, 65.7kg and 67.8kg for 1989, 1990 and 1991 respectively which is markedly increased from the South American records. The latter two years are significantly (p<0.05) higher than the initial year (1989) following importation. Clean fleece weight was similar in the latter two years, averaging 1.8 kg, but fibre diameter was significantly (p<0.05) coarser from 25.2 }, issn = {1176-5283}, author = {Lee J and Harris PM and Sinclair BR and Treloar BP} } @conference {40426, title = {Effect of glucose level in culture medium on survival of in vitro cultured sheep embryos following transfer to recipient ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {255-256}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The commencement and course of cell proliferation is described in proanagen hair follicles of ferrets. Initiation of autumn fur growth was synchronised in 32 animals using melatonin implants. Skin samples containing S-phase cells labelled in vivo with bromodeoxyuridine were collected from groups of four animals up until the time of development of metanagen follicles at 14 days post-implant. Cells were visualised by an indirect immunocytochemical method and counts made of proliferating cells in the hair germ, epithelial strand/outer root sheath, connective tissue sheath and dermal papilla. Telogen follicles showed no labelling in all four tissues until 4 days after melatonin implant. The largest number of proliferating cells were in the hair germ, which formed the new fibre and inner root sheath. The cell labelling index for this tissue remained high at 14 days post-implant. In other tissues, cell proliferation reached peaks during mid to late proanagen, then declined as the metanagen state was reached. These results indicate that some key signalling events controlling ferret hair growth occur between 0 and 4 days after the melatonin implant, and illustrate the separate processes of follicular regeneration and fibre growth occurring in proanagen follicles. }, issn = {1176-5283}, author = {Thompson JG and Simpson AC and Pugh PA and McGowan LT and James RW and Berg DK and Payne SR and Tervit HR} } @conference {40427, title = {Effect of oestrogen pre-treatment and duration of CIDR treatment on pattern of onset of oestrus in ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {257-260}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {When they were weaned at five and a half months of age, 33 Angus heifers were randomly divided into two groups representing different planes of nutrition. From weaning until two months before calving which began on 15 July 1977 the liveweight difference between the two groups was steadily increased until the high plane group (HP) weighed 17 kg more than the low plane group (LP) on 17 May 1977. From then until calving the high plane group was fed to maintain constant liveweight, while the low plane group was fed to gain liveweight at the rate of 0.3 kg/day. When calving began both groups weighed the same average liveweight (415 kg). Calf birth weight was affected by nutritional treatment (HP 26.2 }, issn = {1176-5283}, author = {Smith JF and Parr J} } @conference {40425, title = {Effect of physical parameters on ram spermatozoal motility}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {251-254}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Local sympathectomy was achieved by injecting 6-hydroxydopamine into the dermis at two sites on the right midside of each of three Merino wethers. Saline was injected into matching sites on the left midside. After one week, noradrenaline was injected into one site on each side and saline into the other. Colchicine was administered into all sites immediately after noradrenaline, skin biopsies removed from each site two hours later and histological preparations assessed for the accumulation of mitoses in wool follicles. Compared with saline treated sites, noradrenaline significantly depressed the number of accumulated mitoses at control and sympathectomised sites by 34 and 36\% respectively (P=0.002). A pharmacological dose of noradrenaline therefore has the potential to reduce wool production. Sympathectomy increased mitotic rate at saline and noradrenaline treated sites by 16 and 18\% respectively, although this increase was not significant at the 5\% level (P=0.0094). Elevation of mitotic activity via elimination of endogenous sources of noradrenaline may help to explain the mechanism by which surgical sympathectomy has previously been reported to increase wool production. }, issn = {1176-5283}, author = {Upreti GC and Oliver J and Munday R and Smith JF} } @conference {40402, title = {The effect of pretreatment with progesterone on the oestrous response to oestradiol-17Beta benzoate in the post-partum dairy cow}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {157-160}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Crossbreeding with Booroola Merino rams was initiated in 1986 in Israel to transfer the FecB allele to the Awassi (Aw) and the Assaf (As) dairy breeds to increase their prolificacy. The prolificacy of the F1 ewes was higher by about 0.6 lambs/ewe lambing (P<0.05) over the prolificacy of Aw and As ewes. Growth rate up to 150 days of age did not differ between As, }, issn = {1176-5283}, author = {McDougall S and Burke CR and Macmillan KL and Williamson NB} } @conference {40375, title = {Effect of selection for productive traits on internal parasite resistance in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {53-56}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The distribution of condensed tannins (CT) in plants, their mode of action and benefits to ruminant nutrition are briefly reviewed. Data are presented showing the CT in lotus species reduced rumen degradation of protein and increased its flow to the intestine, but an increased amino acid absorption only occurred with Lotus corniculatus, suggesting the CT in Lotus pedunculatus prevented enzymic hydrolysis of the protected protein. The extent to which CT in Lotus pendunculatus depressed nitrogen (N) digestion was similar when fed as a sole diet and when fed as a third of the diet with pasture. The implications of these results are that both concentration and type of CT are important in affecting nutritive value, and that these factors need to be resolved before an effective plant selection program can be undertaken. }, issn = {1176-5283}, author = {McEwan JC and Mason P and Baker RL and Clarke JN and Hickey SM and Turner K} } @conference {40406, title = {Effect of sire, breed and age on plasma FSH concentrations in FecB FecB and Fec+ Fec+ Booroola rams before and after castration}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {175-178}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Feed intake and wool production data on unmated, single- and twin-bearing/rearing ewes from a year-long field trial were incorporated into feed budget models of a hill country farm. Increasing the basal liveweight of an unmated ewe from an average of 45 to 55 kg increased greasy wool production from 4.15 to 5.10 kg/ewe. Relative to the annual feed requirements (614 kg DM/y) of a typical breeding ewe (1 sheep stock unit (ssu) on the case farm the annual feed requirements of unmated 45, 50 and 55 kg ewes were estimated to be 0.58, 0.66 and 0.72 ssu. At 1991 costs and prices the gross margins (GM) were $15.50/ssu for breeding ewes (100\% lambs weaned) and, depending on liveweight, from $7.12 to $8.11/ssu for the all-wool options. The breeding ewe policy remained more profitable even if low lamb prices or a poor lambing percentage were achieved. }, issn = {1176-5283}, author = {Isaacs KL and McNatty KP and McLeod BJ and Condell L and Littlejohn RP} } @conference {40439, title = {The effect of sward surface height on ingestive behaviour and intake of once-bred and non-pregnant heifers under continuous stocking management in early winter}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {307-310}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Damage to soils and pastures in early Spring is a significant factor reducing pasture growth, feed utilisation and animal production on NZ dairy farms. Farmers have sought and may have found a management solution to this problem. It involves the early removal of dairy cows from pasture, after a period of grazing that is sufficient to meet the dry-matter intake needs of the cows. For example the colostrum herd might graze on pasture only at night, and spend the period between morning and afternoon milkings on the cowshed yard. The main herd will be on pasture during the daytime, but may be taken off pasture at 9.00 after 3 to 4 hours grazing, and stood on the cowshed yard until morning milking. This limits the extent of treading and reduced damage to soils and pasture, allowing the farm to sustain higher pasture growth rates, maintain a higher average pasture cover and achieve a longer first rotation. Dairy farmers have found they can stand lactating dairy cows without special facilities and without the need for supplementary feed provided certain conditions are met. The best place to stand cows from farmers experience is on the cowsheds concrete yard. Cows are used to standing there and the concrete is cleaned daily of stones, so risk of stone bruising to hooves is minimal. While space on the yard is limited, few cows lie down on the concrete. The close contact means they keep each other warm, and they may be less exposed to weather than in the paddock. There appears to be no detrimental effect on daily per cow production from this treatment and production data will present to illustrate this.}, issn = {1176-5283}, author = {Inwood PR and Morris ST and Parker WJ and McCutcheon SN} } @conference {40440, title = {Effects of GnRH and of single versus multiple mating on the conception rate in alpacas}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {311-312}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Herd owners comment that they are having increasing difficulty getting their higher producing, higher Breeding Index (BI) cows to conceive. The reports published on local and overseas data are inconclusive and do not substantiate their concern. A solution to this dilemma would be analyses of contemporary groups within herds with production records stored in the national data base. This would allow for the effects of different feeding practices. Any factor which increased the likelihood of a cow failing to conceive to a first insemination will reduce income by $110/return. If the delay in conception must be rectified by induction, the cost of $320 and increased to $700 if the cow fails to conceive. These changes in income mean that if a herd of 170 cows has its pregnancy rate per breeding reduced from 60\% to 59\%, the estimated loss would total $955. This emphasises the cost of delays in conception date.}, issn = {1176-5283}, author = {Knight TW and Death A and Wyeth T and Hill F} } @conference {40424, title = {Effects of grazing pressure and competition on growth rate of Merino and Romney lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {247-250}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The effect of nutritional management of Angora goats on fibre production and fibre quality was investigated over two years. After shearing in August, does were fed either maintenance (MPA) or ad libitum (HPA ryegrass/white clover pasture (approximately 1.0 kg and >4kg DM/head/day respectively). In October half the does were removed from each allowance group and introduced into the alternate allowance group. This was repeated in early February, allowance groups being balanced for their previous allowance history. Fleece weights were recorded at shearing in February and August. Fibre diameter, medullation and kemp levels were measured at shearing in February and August and also in October and May. Doe live weights were recorded monthly and when fleece measurements were made. After one year of measurements, does were completely randomised onto new pasture allowances and the experiment was repeated. Nutritional treatments generated liveweight differences between HPA and MPA does throughout the year (P<0.05). February fleece weights were similar in both HPA and MPA groups in 1990 (1.73 vs 1.67; s.e.d 0.067 kg for HPA vs MPA respectively) and in 1991 (1.43 vs 1.41; s.e.d 0.060 kg for HPA vs MPA respectively) though approximately 25\% lower than in 1990. August fleece weights were similar in 1990 and 1991 but were approximately 20\% higher in HPA does than in MPA does (1.46 vs 1.26; s.e.d 0.051 kg for HPA vs MPA respectively in 1990 and 1.49 vs 1.20; s.e.d 0.040 kg for HPA vs MPA respectively in 1991). Increased August fleece weight was associated with increased fibre diameter (34.9 vs 32.7; s.e.d 0.52 }, issn = {1176-5283}, author = {Muir PD and Cruickshank GJ and Wallace GJ and MacLean KS and Smith NB} } @conference {40414, title = {Effects of location and source of ewes and rams on the onset of oestrus in Romney ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {207-210}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Spermatozoal motility is known to be influenced both by the diluent used and by the physical parameters involved in the processing of semen. We have evaluated the effect of cooling and dilution on ram spermatozoal motility in a defined semen diluent. The results indicated that ram semen is best stored at 15 C, this temperature being reached by cooling at a rate not greater than 3 C per minute. Time (up to 60 minutes from semen collection) and extent of dilution (500 or 800 x 10 6 spermatozoa per mil) were found to have no effect upon maintenance of spermatozoal motility. }, issn = {1176-5283}, author = {Knight TW and Muir PD and O{\textquoteright}Neill KT and Wallace GJ and Hamilton GJ and McLean K} } @conference {40365, title = {The effects of milking once daily throughout lactation on the performance of dairy cows grazing on pasture}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {13-16}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The influence of selection for rapid (Fast GC) or slow (Slow GC) clearance of exogenous glucose on the pH of lamb meat was investigated using preslaughter stress, adrenaline and energy supplement treatments. Ultimate pH values were elevated (P<0.001) by a high level of preslaughter stress in the Fast GC line only. This response was suppressed by an oral energy supplement, indicating that recharge of muscle glycogen stores was impaired. The demonstration of this genetic relationship makes the selection lines valuable for study of the influence on meat quality of post mortem energy metabolism in muscles. }, issn = {1176-5283}, author = {Holmes CW and Wilson GF and MacKenzie DDS and Purchas J} } @conference {40428, title = {Effects of month and PMSG on the interval from CIDR removal to ovulation in Romney and Merino ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {261-264}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Ingestive behaviour and herbage intake were measured in 36 twenty-month old pregnant and non-pregnant Hereford x Friesian heifers with an initial liveweight of 360 }, issn = {1176-5283}, author = {Knight TW and O{\textquoteright}Neill K and Ridland M and Hamilton G and Death A and Wyeth T} } @conference {40412, title = {Effects of shearing method on the physiology and productivity of sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {199-202}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Three groups of sheep housed in metabolism crates were fed Lotus corniculatus (low tannin), L. pendunculatus (medium tannin) and ryegrass pasture (control) respectively. After a period of adaptation to each of the diets, labelled 35S-cysteine and }, issn = {1176-5283}, author = {Holmes CW and Kamil KA and Parker WJ and MacKenzie DDS and Purchas G and Kidd R} } @conference {40407, title = {Effects of suppressed prolactin levels on wool growth in Romney ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {179-182}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Performance data were collected between October 1985 and October 1991 from a flock of approximately 600 mixed-age Romney ewes allocated to 3 equal sized age-balanced groups and grazed on the same area at Whatawhata Research Centre. Two groups were shorn 3 times in 2 years at approximately 8-monthly intervals. One group was shorn in May, January and October and the other shorn in January, October and May during each succeeding 2 year period. The third group were shorn once-yearly in October. Eight-monthly shorn ewes weaned heavier lambs and grew more greasy and clean wool than once-yearly shorn ewes. Shearing treatment did not affect ewe live weight after shearing in October or any parameter of lamb production, other than lamb weaning weight. Incidence of casting was less than 1\%. Net wool returns from 8-monthly shorn ewes exceeded that of once-yearly ewes with the associated benefit that shearing 8-monthly as a split flock system would improve cashflow relative to a once yearly system. }, issn = {1176-5283}, author = {McCloghry CE and Foldes A and Rintoul AJ and Hollis DE and Baker PJ and Maxwell CA and Kennedy JP and Wynn PC} } @conference {40369, title = {Expected responses in carcass composition to selection for muscularity in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {29-32}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Fifty nine mixed age ewes from high (H) and low (L) faecal egg count (FEC) selection lines were used in a MOET programme. Three years of reproductive data were also recorded in 714 ewes from the 2 selection lines and their control line (C). The mean (}, issn = {1176-5283}, author = {Waldron DF and Clarke JN and Rae AL and Woods EG} } @conference {40371, title = {Factors affecting repeatability of tissue depth determination by real-time ultrasound in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {37-40}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The behaviour of 7476 calves transported on double- or triple- decker trucks was studied during unloading. Recorded behaviour was classified into 2 categories (upright or not upright) and the frequencies of these at three ramp slopes (4.2, 12 and 18.8 ) are presented. The proportions of animals upright on the 3 slopes (low, medium and high) were 93, 74 and 20\%. On average, 100 calves were unloaded in 5.3, 7.7 and 7.1 min down the low, medium and high slopes, respectively. Improvements in welfare of bobby calves and probably reduced bruising would result if ramp slopes were kept at less than about 12 so that most animals could remain upright. }, issn = {1176-5283}, author = {Young MJ and Deaker JM and Logan CM} } @conference {40434, title = {Fibre production, shearing procedure and fleece characteristics of alpacas farmed in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {289-292}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Five treatment groups of 40 fine Merino wethers were offered grazing regimes over 2 treatment periods, to achieve a range of liveweight profiles. The first was from 16 October 1990 to 21 December 1990 while the second continued until 29 August 1991. Treatment period 1 generated significant differences in liveweight (P<0.001) between all groups and thereafter the sheep were grazed in 2 larger mobs consisting of groups 1-3 and 4 and 5. By the end of the first period liveweights were 48}, issn = {1176-5283}, author = {Wuliji T and Davis GH and Andrews RN and Turner P and Moore GH and Dodds KG} } @conference {40395, title = {Genetic parameters and performance of flocks selected for advanced lambing date}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {129-132}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Timing of the LH peak and ovulations in superovulated Coopworth ewes synchronised with progesterone-containing CIDR}, issn = {1176-5283}, author = {Smith JF and Johnson DL and Reid TC} } @conference {40396, title = {Genetic parameters for live weights in fallow deer (Dama dama L.)}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {133-136}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {It is debatable whether or not genotype influences follicle- stimulating hormone (FSH) secretion in the Booroola ram. Where differences in FSH have been reported, these may have been due to effects of sire, breed and age rather than Booroola genotype. The aim of this study was to determine if these factors do influence FecB gene expression in plasma FSH concentrations in the Booroola ram. A total of 45 Booroola rams of known genotype, breed, age and sire were blood sampled (10 ml by jugular venepuncture) once daily for 11 days, castrated, bled once daily for further 13 days, and then three times weekly for a further 7 weeks. There were no gene-specific differences in mean plasma FSH concentrations before or after castration, or in the rate of the post- castration rise in FSH, between FecBFecB (BB) and Fec+Fec+ (++) rams. This was consistent when data from rams of three ages (1, 2 or 3 years) and of either Booroola Merino or Booroola Romney breeds were combined, or when genotypes, were compared within breeds, or within ages. There was, however, a significant effect of sire on plasma FSH concentrations, which was evident before but not after castration. These results suggest that variation in FSH between sire groups may explain differences previously attributed to genotype. }, issn = {1176-5283}, author = {Morris CA and McCall JE and Baker RL and Southey BR} } @conference {40382, title = {Growth and venison production from red deer grazing either red clover or perennial ryegrass/white clover pasture}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {81-84}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Computers will become an increasingly important tool in animal management, as well as in most other areas of agricultural endeavour. Computers are commonly used for recording and analysing both research and centrally located production data, but seldom for on-farm use. This discussion concentrates on the traits that can be recorded at the farm level, and how these records can be used. System specifications for successful on-farm use are also outlined. }, issn = {1176-5283}, author = {Semiadi G and Barry TN and Wilson PR and Hodgson J and Purchas RW} } @conference {40381, title = {The importance of physiological measurements in farm animal stress research}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {77-80}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Planned feeding programmes for farm livestock often require the use of repetitive calculations that vary in complexity. This paper outlines some of the planning tasks which can be performed using computerised models. These include: (1) calculation of nutrient requirements for specific production targets and/or production achievable from specific nutrient intakes (ii) diet formulation using linear programming to provide optimum combinations of dietary ingredients at minimum cost (iii) allocation of pasture to grazing animals based on functions relating herbage allowance or residual dry matter to herbage intake and (iv) medium to long-term feed planning using models that range from simple feed budgets to dynamic whole farm simulations. The planning applications of computers can be complemented with monitoring and record keeping software that allow predicted outcomes to be compared with actual events. Desirable features of computer software include ease of use, flexibility, capacity to link with other programmes, and regular revision and updating. }, issn = {1176-5283}, author = {Ladewig J and Matthews LR} } @conference {40397, title = {Interspecies hybrids of deer - a ruminant resource for gene mapping and quantitative trait studies}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {137-142}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Seasonal variation in prolactin secretion has been associated with changes in the pelage of a number of mammals. The aim of this study was to ascertain whether the suppression of prolactin levels commencing in late summer, affects wool growth in sheep with a seasonal pattern of wool growth. Twenty Romney ewes (n=10/group) received either 50mg bromocryptine (Parlodel LA}, issn = {1176-5283}, author = {Tate ML and Manly HC and Emerson BC and Fennessy PF} } @conference {40430, title = {Investigations of wool follicle morphology and cell proliferation in sheep with different levels of wool production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {273-276}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied }, issn = {1176-5283}, author = {Holle SA and Harris PM and Davies AS} } @conference {40413, title = {Lamb and milk production in Awassi, Assaf, Booroola-Awassi and Booroola-Assaf sheep in Israel}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {203-206}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The growth rates of Merino and Romney lambs were compared at three stocking rates (200, 100 and 50 lambs/hectare) but at the same herbage allowance (2 kg DM/head/day). To achieve this, lambs at lower stocking rates were allocated different areas (0.21, 0.4 and 0.8 ha) and shifted at different frequencies (5.1, 9.8 and 24.5 days, respectively). At each stocking, rate groups of 10 lambs of each breed were grazed both separately and together. Each treatment was replicated. Grazing clocks were used to record grazing times in the mixed grazing groups at both the high and low stocking rates. Romney lambs grew significantly faster than Merinos (P<0.001) at all stocking rates. As stocking rate increased there was an overall decrease in LWG (P<0.001). However LWG of Merinos decreased at a significantly faster rate (P<0.005). The effects of stocking rate on breed differences in LWG were supported by grazing data. At 50 lambs/ha, Merinos and Romneys grazed for 10.5 and 11.1 hrs/d, respectively. At 200 lambs/ha, Merinos grazed for 7.2 hrs/d, compared with 11.0 hrs/d Romneys. The pattern of grazing also changed, with Merinos spending more daytime grazing as stocking rate increased from 50 to 200 lambs/ha (60\% versus 82\%) whereas Romney continued to spend 80\% of total grazing time as daytime grazers. }, issn = {1176-5283}, author = {Gootwine E and Braw-Tal R and Bor A and Goot H and Shalhevet D and Zenou A} } @conference {40374, title = {Lambs selected for fast glucose clearance have high meat pH levels when stressed before slaughter}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {49-52}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Two groups of 10 intact Border Leicester ram lambs (10 weeks old; 22.7}, issn = {1176-5283}, author = {Bray AR and Francis SM and O{\textquoteright}Connell D and Bickerstaffe R} } @conference {40388, title = {Magnesium Solubility in the caecum in response to pH changes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {103-106}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {We examined the practicality of using a combination of protein polymorphism and DNA fingerprinting to match up hinds and calves in nine separate mating groups of red deer with between 8 and 21 progeny each. Variation in 10 polymorphic proteins excluded 0.61 to 0.89 of the possible dam-calf combinations in each sire group, leaving between 2 and 200 pedigree combinations per group to be solved by DNA fingerprinting. Of the 44 sire-dam-calf combinations tested by DNA fingerprinting, 22 were excluded, while four calves matched the parents at all bands. However, 16 pedigrees were equivocal, due to the fact that one or both parents were not in a lane directly adjacent to the calf on the fingerprinting gel. The low probability of exclusion of protein testing in some sire groups, combined with the practical limitation of having to run each possible pedigree combination side by side on DNA fingerprinting gels, mean that the present techniques do not provide a routine method for identifying the dam-calf pairings in red deer mating groups on farms. }, issn = {1176-5283}, author = {Dalley DE and Isherwood P and Sykes AR and Robson AB} } @conference {40435, title = {Management effects on seasonal fibre quality in Angora goats}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {293-296}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Lambs grazing ryegrass infected with endophyte (Acremonium lolii) may exhibit staggers or diarrhoea or both, with little correlation between these two conditions. Associated mycotoxins/toxins other than the staggers-inducing lolitrems are likely to be responsible for metabolic changes causing reduced intake, elevated temperature and diarrhoea. These mycotoxins are not necessarily confined to the base of the leaf sheath and stem as is the case for lolitrems. The distribution of mycotoxins to proximal portions of vegetative ryegrass and the effect of these plant components on grazing animals was investigated. Following experimental confirmation in 1991 of nil correlation between staggers and diarrhoea, groups of lambs were grazed in autumn 1992 on 100\% endophyte-infected hybrid ryegrass cv. Grasslands Marsden (Lollium boucheanum Kunth.), using a leader-follower system. Upper and lower leaves, and pseudostem were progressively removed by four groups of lambs on three day breaks, replicated twice. Liveweight gain ranged from 164 g/day in lambs having first offer, to 28 g/day in those grazing the base of the plants (P<0.01). Rectal temperature averaged 40.2 C being slightly above normal in all treatments. Faecal moisture was high; ranging from 79-87\% throughout the experiment with no significant differences due to treatment. Observed faecal soiling was greatest in lambs receiving high leaf component (P<0.05). Clinical staggers, barely detectable in lambs grazing leaf, became severe as the proportion of pseudostem in the diet increased (P<0.01). In contrast to the clear association between endophyte and staggers in lambs grazing the base of infected ryegrass, consistently high faecal moisture, and consequent faecal soiling occurred regardless of the part of the plant consumed, but tended to be greatest in lambs grazing leaf. Analysis of plant components suggested that peramines may be associated with this problem.}, issn = {1176-5283}, author = {Bown MD and Clayton JB and Bigham ML} } @conference {40410, title = {Measurement of foetal size by ultrasonography and progesterone concentrations in pregnant alpacas}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {191-194}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A high fleece weight Romney breeding flock (HFW) and a contemporary random control flock (RC) has been established at MAF Technology Woodlands Research Station by the intensive screening of ewe and ram hoggets from commercial flocks. This paper summaries production traits including reproductive performances, liveweight and fleece weight of the ewe flocks over the 7 years. The ovulation rate and number of multiple births per ewe lambed were higher for HFW than RC ewes 1.84 vs 1.75 (SE0.02, p<0.01) and 0.62 vs 0.56 (0.02, p<0.05). Number of lambs born per ewe joined, number of lambs reared per ewe lambed, the number of lambs weaned per lamb born and number of lambs weaned per ewe joined in HFW were 1.49 (SE0.02), 1.37 (0.02), 0.84 (0.01) higher in HFW (65.4kg; SE2.4) than in RC (61.3 kg; 2.4). The greasy fleece weight averaged 4.55 kg (SE 0.21) for HFW and 3.87 kg (0.21) for RC. This represents an average advantage of 17.6\% (P<0.001) to HFW over 7 production years. The results indicate that the single trait selection for fleece weight will be associated with increases in other important productive traits in long woolled sheep. }, issn = {1176-5283}, author = {Ridland M and Knight TW and Wyeth TK} } @conference {40403, title = {Melatonin for cashmere production in breeding does}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {161-164}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Differences in onset of oestrus in Romney ewes has been observed between locations at similar latitudes in the North Island. Two experiments compared source of ewes and rams, and time of transfer of ewes between locations on the onset of oestrus in Romney ewes. In Expt 1, groups of 30 ewes were interchanged between Wanganui and Takapau on 14 Nov, 5 Dec and 8 Jan. The next day these ewes plus 30 local ewes were joined with 3 Poll Dorset rams. There were no effects of ewe source but ewes at Takapau joined on 15 Nov, 6 Dec and 9 Jan had earlier onsets-of-oestrus than ewes at Wanganui (P<0.05 to P<0.01). Ewes joined on 15 Nov and 6 Dec at Wanganui had a later (P<0.01) onset of oestrus than ewes joined on 9 Jan. In Expt 2, 60 ewes and 3 Poll Dorset rams were interchanged between Wanganui and Poukawa on 13 Nov. These ewes plus 60 local ewes were randomly divided in half and recombined to form 2 mixed groups which were joined with 3 Poukawa or 3 Wanganui Poll Dorset rams. Onset of oestrus was earlier at Poukawa (P<0.001) and for ewes joined with Wanganui rams (P<0.001) but there were no effects of ewe source. }, issn = {1176-5283}, author = {O{\textquoteright}Neill KT and Litherland AJ and Hamilton G} } @conference {40400, title = {Melatonin secretion in Romney ewes differing in wool growth and reproduction is not aligned to photoperiod during spring and summer}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {149-152}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A progeny test involving Romney (n=5) and Poll Dorset (n+5) rams mated to Romney ewes was conducted to examine the relationship between testis size and endocrine parameters, measured during the transitional period from the non-breeding to the breeding season, in rams, and reproductive performance of their daughters in the first and second breeding seasons. More of the Poll Dorset cross hoggets reached puberty during the first breeding season (80 v. 60\%; P<0.01) associated with earlier onset (13 v. 22 May; P<0.10) at younger ages (264 v. 276 days; P<0.10) and more oestrous cycles (2.7 v. 2.0; P<0.05) than for Romney hoggets. The date of onset of the second breeding season was influenced by breed (P<0.001) and sire within breed (P<0.05). These differences between Romney and Poll Dorset cross animals in reproductive performance were associated with differences between their sires in the pattern of seasonal variation in testis size and plasma gonadotrophin concentrations. However, within-breed correlations between testicular and endocrine parameters in the sires and date of onset of the breeding season in the offspring were low. It is concluded that, while some of the testis and endocrine parameters could potentially be used as selection criteria for date of onset of the breeding season in ewes, further studies are needed before these parameters can be incorporated into selection programmes. }, issn = {1176-5283}, author = {Scott IC and Heath D and Hawker H} } @conference {40399, title = {Modelling herd efficiency in liveweight-selected and control Angus cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {145-148}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The growth and sexual development of red deer calves born early (12 male, 12 female), with an average birth date of 22 October 1990 }, issn = {1176-5283}, author = {McMillan WH and Morris CA and McCall DG} } @conference {40417, title = {A modelling study of the productivity and profitability of unmated and mated ewes on North Island hill country}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {221-224}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Five groups (15-30) of Romney or Merino ewes were synchronised with CIDR devices for 12 days in March or April. In all but one group of Romney ewes 400IU PMSG was injected at CIDR removal. Intervals to onset of oestrus and ovulation were determined by recording crayon marks and laparoscopy respectively every 4 hours. Interval to ovulation was not affected by ewe breed or month of treatment, but it was 7.9 hours earlier in ewes injected with PMSG (48.9h vs 56.8h P<0.001) and the variance was less (13.4h vs 35.7h P<0.05). Interval to oestrus was affected by breed of ewe, date of synchronisation and use of PMSG. }, issn = {1176-5283}, author = {Parker WJ and Gray DI and Morris ST and McCutcheon SN} } @conference {40393, title = {The National Database for sheep genetic evaluation and research}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {121-124}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Lactating and non-lactating does were allocated on August 1989 down lengths to seven groups. Four of the groups received a single slow release melatonin implant (Regulin) on either 16 October, 30 October, 13 November or 25 November 1989. Two groups received single implants on 16 October and 25 November or 13 November and 25 December. The seventh group was an untreated control. Total down length in all treated groups was greater than the control (p<0.005). The goats treated on 16 October had the greatest response to melatonin and produced a 45\% longer down fleece than the controls. The first fleece (16.8 }, issn = {1176-5283}, author = {Garrick DJ and Clarke JN and Callow CF} } @conference {40361, title = {The New Zealand Society of Animal Production - After the Jubilee}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {1-2}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Rib-eye muscle (M. longissimus lumborum) area (REA) and depth (B) at the 12th rib were ultrasonically measured on 89 ram lambs from 3 sire breeds. The lambs were then slaughtered and these live measures plus carcass weight were evaluated as predictors of the corresponding carcass measures and the following two measures of muscling, based on four muscles surrounding the femur bone and the femur itself: 1. Muscle:Bone ratio (M:B), and 2: Muscularity (MUSC), defined as an index of muscle depth (square root of the weight of the four muscles per unit femur bone length) relative to a skeletal dimension (femur length). Prediction of carcass REA and B from ultrasonic REA and B, after adjusting for carcass weight, was more effective for B (partial r=0.40) than REA (partial r=0.18). The main problems with prediction arose with higher values (B>33mm), when ultrasonic values underestimated actual carcass values. REA and B (ultrasonic live and direct carcass) significantly (p<0.001) improved the prediction of MUSC or M:B over carcass weight alone, but did not account for the highly significant (P<0.001) breed effect on these traits. It is concluded that ultrasonic and carcass measures of REA and B provide useful but limited information on lamb leg muscularity. }, issn = {1176-5283}, author = {Nicol AM} } @conference {40383, title = {Nutrient supply for lamb growth from Grasslands Puna chicory (Cichorium intybus) and Wana cocksfoot (Dactylis glomerata)}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {85-88}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The long-term success of any recording scheme depends on access to a genetically-structured database of performance records. Ram breeders in New Zealand have indicated preference for a system providing within-flock breeding value prediction via on-farm personal computers or through commercial bureaux on a regional level. This paper describes recent developments in industry structure in relation to animal evaluation and access to field data for research. Ram buyers, breeders and extension agents all benefit from consistent techniques for calculating and summarising the breeding worth of animals. The within-flock methodology prototyped in Animalplan has now been used to form the basis of a "genetic engine", available under licence, for incorporation into commercial programmes with database and reporting capabilities. Across-flock genetic evaluation (e.g. sire reference analyses) may require access to information from a number of distributed databases. A national identification system which recognises animals used in flocks other than their birth flock is re-requisite to analysis. The National Database has been initiated to ensure the integrity of data and to safeguard such pedigree and performance records for a wide variety of purposes. It will be updated annually to provide a single source for across-flock Best Linear Unbiased Prediction (BLUP) evaluation. The provision of the National Database ensures continued access to field data for animal breeding and other applied research. Genetic development of the scheme will come from improved specification of the production model (e.g. new traits and indicators of non-genetic effects) and from improve statistical approaches (e.g. BLUP and estimates of distributed parameters), all requiring access to and analysis of large bodies of genetically-structured field data. }, issn = {1176-5283}, author = {Komolong K and Nicol AM and Poppi DP and Fraser TJ and Kirsopp S} } @conference {40387, title = {Nutritional effects on the calpain system in skeletal muscle of sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {101-102}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Deer are unique among New Zealand{\textquoteright}s farmed ruminants in the existence of hybridising species and subspecies which exhibit major differences in physiology and production traits. We used protein electrophoresis to examine genetic differences between two farmed deer species with fertile hybrids:red deer (Cervus elaphus) and Pere David{\textquoteright}s deer (Elaphurus davidianus) (in both species 2n=68). Fixed differences between the species were found for 19 proteins. A further 3 proteins were polymorphic in red deer but not in Pere David{\textquoteright}s deer. Using the present techniques, segregation of 17 of the protein differences between the species could be confirmed in a backcross pedigree to red deer. The large number of genetic markers segregating in backcross hybrids make them an excellent resource for gene linkage mapping among genetic markers and for experiments which examine the relationship between genetic markers and quantitative traits. }, issn = {1176-5283}, author = {Thomson BC and Oddy VH and Sainz RD} } @conference {40384, title = {The nutritive value of Lotus for sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {89-92}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A large-scale screening operation over two seasons by Landcorp Farming Ltd has established a terminal sire-breeding programme for sheep. Within the North and South Islands, screened hoggets were transferred to Huirimu Station and Kepler Station respectively. In 1989, 2,046 ewe hoggets (0.8\%) were screened on liveweight from 248,500 animals in 114 flocks. Mean pooled population weight (adjusted to 18 December) was 43.2 }, issn = {1176-5283}, author = {Waghorn GC and Shelton ID} } @conference {40368, title = {Oestrus synchronisation and oestrus detection in Swamp Buffaloes (Bubalus bubalis)}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {25-28}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Selective mating of Perendale sheep for increased or reduced susceptibility as lambs to an experimental challenge with Haemonchus contorus commenced in 1986. Four years later changes were assessed by monitoring faecal nematode egg count (FEC) in ewes and their progeny. In the absence of drenching, mature flock ewes were given 7000 infective larvae of H. contortus and 3000 larvae of Trichostrongylus colubriformis in mid May 1990 after mating. FEC were monitored at regular intervals during pregnancy and 4 times during the periparturient period. Ewe and ram lamb progeny were faecal sampled on 5 occasions between weaning (November 1990) and May 1991. Lambs were drenched at most sampling dates. All stock were grazed across pasture contaminated previously with mixed parasite populations. Adult ewes selected as lambs for Resistance (low FEC) shed fewer eggs than Susceptible (high FEC) line ewes throughout pregnancy, 2 weeks pre- and 3, 6 and 9 weeks post-parturition. At the periparturient peak, approximately 3 weeks after lambing, Low FEC line ewes maintained FEC which were only 25\% of those in the High FEC line. Lambs from the Low FEC line had significantly lower FEC than their High counterparts on 3 of 5 sample dates (P<0.01). At the final sample date (30 April 1991), there was a 10-fold difference in mean FEC between extreme sire groups. Bulked faecal cultures demonstrated that Haemonchus and Trichostrongylus were the dominant genera. }, issn = {1176-5283}, author = {Hill FI and Knight TW and Death AF and Wyeth TK and Ridland M} } @conference {40420, title = {A pilot evaluation of shedding sheep breeds compared with non- shedding breeds for susceptibility to nematodes and flystrike}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {233-236}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The effects of ovine placental lactogen (oPL) on wool follicle development were examined in chronically catheterised singleton Dorset foetuses. From days 122 to 136 of gestation, five foetuses were infused intra-arterially with purified oPL (1.2 mg/day) in a carrier medium consisting of sterile physiological saline plus 15\% plasma from non- pregnant ewes while another five were infused with carrier medium alone. Foetal arterial plasma concentrations of oPL were increased six-fold by the infusion compared with those in controls. Foetuses were euthanased on day 136 of gestation and skin samples excised from the midside for histological examination. Treatment of foetuses with oPL did not influence primary follicle density but reduced the ratio of immature secondary follicles to primary follicles (Control, 1.22 vs oPL-treated 1.01, Pooled SE = 0.06, P=0.06). These data provide the first evidence that follicle development in the lamb may be regulated by ovine placental lactogen. }, issn = {1176-5283}, author = {Litherland AJ and Sorenson E and Niezen J and Bishop D} } @conference {40438, title = {Precalving nutrition of heavy two year old Angus heifers weighing 415 kg at calving}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {303-306}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A short term grazing trial was conducted on a central Taranaki dairy farm to study the effects on milk production of regular light dressings of nitrogen fertiliser (N), when compared to a single heavy application. Fifteen paddocks were allocated to each of two treatments. Both treatments consisted of 50 kg N/ha applied as either a single heavy application (50 kg N/ha) on 10 September (50x1 treatment), or frequent light applications (10 kg N/ha), applied progressively from 10 September directly after the following 5 grazings (10x5 treatments). Grazing of herd alternated between the two treatments with 6 paddocks of one treatment being grazed for 4 consecutive days. Total milksolids (MS) production data was obtained for days 3 and 4 of each grazing period. Total net herbage accumulation from August to mid-January was similar for the two treatments even though there was a difference in the pattern of accumulation. The 50x1 treatment resulted in 28\% higher net herbage accumulation between 12 November and 11 January. Botanical composition of the pastures in September, November and December indicated that 50x1 treatment increased the ryegrass content in November. Total MS production was 400 kg MS/ha between 1 October and 10 January for both treatments. The monthly MS production differences between the treatments were small. The results show there to be no advantage in terms of MS production to light regular applications of nitrogen fertiliser when compared to a single heavy application.}, issn = {1176-5283}, author = {Pleasants AB and Barton RA} } @conference {40363, title = {Production, Economic Performance and Optimum Stocking Rates of Holstein-Friesian and Jersey Cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {7-10}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The present New Zealand export lamb carcass classification system places carcasses into groups differing on average in fat (and meat) proportion (e.g. YM=20.6\% fat, PM=23.8\% fat, TM=27.0\% fat and FM=28.2\% fat). There is, however, considerable overlap in fat proportion between adjacent fatness classes. A comparison of the present mainly visual assessment system (one grader) with one based solely on measurement has shown that the objective systems investigated to date do not bring any major improvements in terms of sorting carcasses on the basis of composition. However, other advantages associated with an objective system, including the ability to sort out carcasses of any desired fatness range which may differ from current specified class ranges, makes the introduction of an instrument measurement based system extremely likely in the near future. As yet, a satisfactory instrument for this purpose has not been identified. }, issn = {1176-5283}, author = {Ahlborn G and Bryant AM} } @conference {40436, title = {The reduction of cell division rate in wool follicles by noradrenaline}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {297-298}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A field trial at Flock House over a three year period (July 1989 - March 1992) compared the performance of grazing bulls alone at three stocking rates (3.0, 3.7 and 4.5 bulls/ha) with grazing bulls at 3.0 bulls/ha with an increasing stocking rate of goats (3, 7 and 13 Angora does/ha). The respective stocking rates in stock units (su/ha) for the six respective treatments from bulls alone at increasing stocking rate to bulls with goats at increasing stocking rate of goats were 15, 19, 23, 18, 21 and 26 su/ha respectively. Weaner bulls were brought onto the farmlets in November each year and all rising 2 year bulls were sold off the farmlets over January to April at 18-21 months of age. Bull growth rates were significantly depressed by increasing the stocking rate of bulls but were unaffected by an increasing stocking rate of does. Bulls in the bull/goat treatment at 26 su/ha grew at a similar rate of bulls but were unaffected by an increasing stocking rate of does. Bulls in the bull/goat treatment at 26 su/ha grew at a similar rate to bulls alone, stocked at 15 su/ha. Goat performance; kidding, kid fleece weight and doe fleece weight were not affected by goat stocking rate. However at the high doe stocking rate, kid liveweight at weaning and doe liveweight (March) was reduced (P<0.01 and P<0.05 respectively). Stocking rate treatments had little effect on the economic farm surplus (variation between $680/ha for the least profitable to $730/ha for the most profitable treatments). However with a more buoyant mohair market and a more robust/productive strain of Angora goat ie. the Zimbabwe Angora, it is assumed that bull/goat system would be more profitable than bulls alone. Although goats were not complementary to bull beef production they were also not competitive with bulls over the stocking rates investigated.}, issn = {1176-5283}, author = {Scobie DR and Hynd PI and Setchell BP} } @conference {40378, title = {Reproduction in flocks selected for and against lamb faecal egg count}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {65-68}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The calpain system consists of two enzymes and their endogenous inhibitor, calpastatin, and is involved in the breakdown of myofibrillar protein in skeletal muscle. We have investigated the relationship between the calpain system and protein degradation in sheep under three different feeding regimes. Calpain were separated from fresh muscle using a DEAE-Sephacel ion exchange column. Calpain I and calpastatin activities were higher in the restricted group than in the ad- libitum group. Fasting increased calpastatin but had no effect on the calpain I activity. There was a positive relationship between the calpastatin : calpain I ratio and protein degradation and a negative relationship with calpain I. This result is at variance with the idea that calpain I activity limits the rate of protein degradation. }, issn = {1176-5283}, author = {McMillan WH and Hall DRH and Watson TG} } @conference {40421, title = {Reproductive performance and liveweight in Romney sheep selected for fleece weight and a control flock}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {237-240}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Genetic and nutritional factors that cause marked changes in wool growth influence the content (}, issn = {1176-5283}, author = {Wuliji T and Dodds KG and Andrews RN and Turner P and Wheeler R} } @conference {40433, title = {Responses to selection for wool staple strength in Romney sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {285-288}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {In a series of studies, relationships between herbage allowance (as measured by sward surface height (SSH), herbage intake (measured by intraruminal chromium controlled release capsule) and production were assessed in continuously stocked winter (June)- and spring (August)- lambing pregnant and lactating ewes. At SSHs of 2.8, 4.0, 7.1 and 8.5 cm, organic matter intakes (OMI) of winter-lambing ewes in the last month of pregnancy were 1.4, 1.7, 1.6 and 1.9 (Pooled SE = 0.1) kg/d (P<0.05), respectively. Ewe liveweight gain over the last month of pregnancy increased with SSH but there was no effect of SSH on lamb birthweight or ewe midside wool growth. Similarly, pregnant spring- lambing ewes had OMI of 1.4, 1.7, 1.8 and 1.9 (PSE = 0.1) kg/d (P<0.05) at SSHs of 2.7, 4.0, 5.9 and 7.8 cm, respectively and ewe liveweight gain increased with SSH but there was no effect of SSH on ewe wool growth or lamb birthweight. Results suggest that both winter- and spring-lambing ewes can tolerate SSH below 3 cm during late pregnancy without detrimental effects on lamb or wool production. Winter-lambing lactating ewes (first two months of lactation) had OMI of 1.8, 2.3 and 2.5 (PSE = 0.1) kg/d (P<0.05) at SSHs of 2.6, 4.4 and 7.8 cm respectively. Sward height did not influence ewe wool production or lamb growth but ewes on the 2.6 cm sward lost 8-10 kg more liveweight during lactation than those on the 4.4 and 7.8 cm swards. Spring- lambing ewes had OMI of 1.8, 2.0, 1.9, 2.0 and 2.0 (PSE = 0.3) kg/d (P<0.1) at SSHs of 3.5, 5.0, 6.0, 7.0 and 8.5 cm, respectively. There were no effects of SSH on ewe wool growth or lamb growth but ewe liveweight loss was greatest at low SSH. Results are discussed in the context of feeding recommendations for winter- and spring-lambing ewes.}, issn = {1176-5283}, author = {Bray AR and Smith MC and Woods JL and Baird DB} } @conference {40429, title = {A review implicating a two compartment model for the processes of cell division and differentiation in the Wool Follicle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {265-272}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The effects of injecting GnRH at mating and of single vs multiple matings on the conception rate in alpacas were investigated in two experiments. In Experiment 1, 33 low liveweight (48.4 }, issn = {1176-5283}, author = {Scobie DR and Woods JL} } @conference {40390, title = {The role of computer software in the feeding of farm livestock}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {111-114}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Romney ewes with consistently high (H, n=5) or low L, n=5) seasonal changes in wool growth and with differences in ovulation rate and the onset of anoestrus, were blood sampled every 30 min for 24 h at the winter and summer solstices and at the spring and autumn equinoxes. Plasma samples were assayed for melatonin by direct radioimmunoassay. Mean melatonin levels were higher during the hours of darkness than during daylight at all sampling times. However, the ratio between day- and night-time melatonin levels tended to be smaller in spring (1.8) and summer (1.5) than autumn (2.9) and winter (1988 - 3.8; 1989 - 4.1). There were no significant differences between H and L ewes in mean melatonin concentrations during daylight or darkness at any of the seasons. There was however, considerable variation between individual ewes in the diurnal pattern of melatonin secretion in spring and summer. The high levels of melatonin usually associated with darkness were sometimes found during the day. These disrupted patterns of melatonin secretion occurred in all ewes at one or other of these two seasons. The results suggest that during anoestrus, melatonin profiles may differ from the normal pattern of secretion that is aligned to photoperiod. }, issn = {1176-5283}, author = {Brookes IM and Parker WJ and Gray DI} } @conference {40404, title = {Seasonal effects on the efficacy of intravaginal CIDR devices for oestrous synchronization of farmed fallow deer (Dama dama)}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {165-170}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The production of the Woodlands high prolificacy flocks was compared to industry control animals. Effects of the Inverdale gene (FecX}, issn = {1176-5283}, author = {Morrow CJ and Asher GW and Smith JF and Jabbour HN and Mulley RC and McLeay LM} } @conference {40419, title = {Sheep growth rates under Pinus Radiata}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {229-232}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Preliminary results are given of a study of follicle differences between a progeny-tested fleeceweight (FWT) line of sheep and a control (CLT) flock which was conducted during winter. Measurements using immunocytochemistry and image analysis on skin biopsies were based upon the use of intracutaneously administered bromodeoxyuridine (BrdU) to assess the replicating cell population in wool follicles. The FWT animals showed a significant advantage over the CLT animals in number of replicating cells, papilla length, papilla area and area of replicating zone in the follicle bulb. There were no significant differences between the flocks in the ratio of primary to secondary follicles or in the number of active follicles. The mitotic density was similar in both flocks. The greater productivity of FWT sheep appears to be accounted for by a larger proliferative zone rather than a higher cell replication rate. }, issn = {1176-5283}, author = {Hawke MF and Percival NS} } @conference {40422, title = {Slimming diets for overfat lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {241-242}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Wool staple strength was determined in 2120 Romney ewes from 12 sources and 242 Romney rams from 3 sources between 1986 and 1988. Positive, negative and random selection formed High Strength, Low Strength and Control lines, each with 80 ewes and 10 sires. Since 1989 ewe and ram replacements have been selected from within the lines and the number of breeding ewes per line increased to 100. Staple strength was 25\% greater in the High Strength line and 15\% lower in the Low Strength line than in the Control line when fleeces of hoggets born in the selection lines from 1986 to 1989 were compared (P<0.01). Positively correlated with the staple strength response were responses in staple length, fibre diameter, clean fleece weight and fibre length after carding. The major effect to date of selection for increased staple strength has been to enhance wool growth, with the consequent increase in fibre diameter contributing to the improvement in staple strength. The increase in both the strength and length of staples will have contributed to the increase in fibre length after carding. These preliminary results demonstrate that direct selection for staple strength has been successful. The staple strength response and associated responses in wool production and wool characteristics were of benefit to both producers and processors. }, issn = {1176-5283}, author = {Cruickshank GJ and Muir PD and MacLean KS} } @conference {40373, title = {Subcutaneous fat distribution as assessed by ultrasound in Border Leicester and Dorset Down ewe hoggets}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {45-48}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A study of growth and venison production from weaner red deer grazing pure "Pawera" tetraploid red clover (RC) or conventional perennial ryegrass/white clover (PRG) pasture was conducted, with the objective of attaining a minimum slaughter liveweight (92 kg; 50 kg carcass) by 12 months of age in the stags. Ten weaner red deer stags and 10 weaner red deer hinds were rotationally grazed on either RC or PRG pasture. In autumn and spring, forage allowances were respectively, 7 kgDM/h/d and 8 kgDM/h/d. In winter, the animals from both groups were grazed together on PRG pasture, at a residual dry matter of 1100 kg/DM/ha; 0.5 kgDM/h/d of meadow hay was also provided. Liveweight gains of RC and PRG stags were respectively 263 vs 192 g/d, 101 vs 106 g/d and 362 vs 341 g/d during autumn, winter and spring. With hinds, the liveweight gains of RC and PRG groups were respectively 198 vs 173 g/d, 52 vs 53 g/d and 242 vs 218 g/d during autumn, winter and spring. Animals grazing RC pasture had significantly higher liveweight gain during autumn (p<0.01), but not in winter and spring. At one year of age, stags grazing RC were 7 kg heavier and hinds 3 kg heavier than animals grazing PRG pasture. Animals grazing RC pasture had higher voluntary feed intake (VFI) in both autumn (p<0.10) and spring (p<0.001), than animals grazing PRG pasture. All stags grazing RC pasture reached the minimum slaughter liveweight by one year of age, compared to 75\% grazing PRG pasture. Stags that had grazed RC produced heavier carcass weights (59.9 vs 54.5 kg, p<0.01), and had higher carcass dressing percentage (55.3 vs 53.2\%, p<0.01). RC has potential as a special purpose forage for the growth of weaner red deer. }, issn = {1176-5283}, author = {Deaker JM and Young MJ} } @conference {40431, title = {Suppression of secondary wool follicle development by administration of placental lactogen to ovine foetuses}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {277-280}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied.}, issn = {1176-5283}, author = {Wickham GA and Schoknecht PA and Currie WB and Bell AW and McCutcheon SN} } @conference {40394, title = {A terminal sire breeding programme based on screening for hogget liveweight}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {125-128}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Eighty mature fallow deer does were allocated to four treatment groups (n+20) for which oestrous synchronization treatment consisted of intravaginal insertion of single CIDR devices for 14 days and prostaglandin administration on days 0 and 10 of device insertion. Treatment groups were staggered successively by 7-day intervals from early March to late May, the period spanning the natural mating season (rut). Observations to determine the onset of oestrus were performed 24-72 hours after CIDR device withdrawal and blood samples were collected four times during insertion and then every 2 days, for 14 days, from CIDR device withdrawal. Plasma samples were analysed for progesterone concentration to determine luteal development. A group of untreated contemporary control does were allowed to mate naturally to crayon-harnessed bucks to determine the period of the 1990 natural rut. Oestrus and ovulation were detected on 69\% and 80\% of occasions respectively following CIDR device withdrawal, with ovulation following oestrus on 98\% of occasions. Ovulation not preceded by observed oestrus, probably representing silent ovulations, occurred early in the breeding season. There was complete failure of response, in terms of does exhibiting oestrus increased from 0-10\% to 89-100\% with the greatest coinciding with the onset of the natural rut. In addition, the mean interval from CIDR device withdrawal to onset of oestrus tended to decrease from between 71-88h to 47-63h and oestrous synchrony improved progressively during the trial. The efficacy of CIDR devices in synchronizing oestrus and ovulation in fallow deer does is clearly influenced by timing of treatment relative to the natural breeding season of the herd. }, issn = {1176-5283}, author = {Nicoll GB and Alderton MJ and Annandale DD and Coleman ID and Grimwood TJ and Thomson JA} } @conference {40411, title = {Testis size and endocrine parameters in rams as predictors of aseasonality in their daughters}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {195-198}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Overseas data suggest that feeding low energy/high protein diets can increase carcass weight (and muscle mass) while reducing fat content. The potential application of this technique to maximise the returns from overfat lambs in New Zealand was studied. One hundred and sixty ewe lambs, assessed as being overfat, were allocated on a liveweight basis to one of seven treatment groups. These comprised an initial slaughter group, 2 groups offered pasture at approximately maintenance allowance, 2 groups offered pasture at approximately half maintenance plus 200g/d of a high protein pellet and 2 groups held on a bare paddock and offered ad lib straw plus 200g/d of a high protein pellet. One group from each treatment was slaughtered after 3 weeks and the second after 5 weeks of controlled feeding. Liveweight change, carcass weight and carcass fatness were monitored. All groups lost liveweight (88-195 g/d) and estimated carcass weight (37-89g/d) over the experiment. Corrected to a common carcass weight of 15.25kg decreased GR from 11.6mm for the initial slaughter group to 9.7 and 9.2mm after 3 and 5 weeks, respectively of maintenance pasture feeding. Corresponding GR{\textquoteright}s of the supplemented groups were 9.3mm (both groups) after 3 weeks and 8.1 and 7.5mm after 5 weeks for straw and pasture based diets respectively. Supplementation with a high protein diet was effective in reducing carcass GR measurement after 3 weeks of supplementation with a further decrease after 5 weeks. However, unsupplemented lambs also showed a decrease in GR after 3 weeks, which was not significantly different from supplemented lambs. The length of feeding required to effect a change negated the advantage of decreased GR, although economic returns could be achieved if the pellets were more readily accepted. }, issn = {1176-5283}, author = {Xu ZZ and McDonald MF and McCutcheon SN and Blair HT} } @conference {40405, title = {Timing of the LH peak and ovulations in superovulated Coopworth ewes synchronised with progesterone-containing CIDR devices}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {171-174}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A replicated trial with 4 stock rates of {\textquoteright}wet{\textquoteright} ewes (9.0, 10.5, 12.0, 13.5 sheep/ha) and 4 stocking rates of {\textquoteright}dry{\textquoteright} ewes (11.0, 13.5, 16.0, 18.5 sheep/ha) was established at the DSIR Grasslands {\textquoteright}Ballantrae{\textquoteright} Hill Country Research Station to enable hill country farmers to make informed decisions as to the economics of farming breeding or unmated ewes. Stocking rate had a large effect on liveweight throughout the year with the greatest effect being in winter. Mean weaning weight of lambs was 25.4 kg at 9.0 ewes/ha and 19.7 kg at 13.5 ewes/ha. Dry ewes grew more greasy wool/ha than wet ewes (P<0.05). Greasy wool production ranged from 41.6 kg/ha at 9 wet ewes/ha to 81 kg/ha at 18.5 dry ewes/ha. At 13.5 sheep/ha dry ewes grew 28\% more greasy wool than wet ewes which reared 1.2 lambs to weaning. November/December fleece weight/ha was unresponsive to increasing stocking rate for both wet and dry ewes (P<0.01). November/December fleeces were 18.6\% heavier from ewes in paddocks having a sunny aspect than in paddocks with a predominantly shady aspect (P<0.001). Slowest wool growth occurred during August, being 5.3 to 8.3 mm/month and maximum wool growth occurred during January within the range 17.3 to 18.5 mm/month. }, issn = {1176-5283}, author = {Thompson JG and Simpson AC and James RW and Tervit HR and Asher GW and Peterson AJ} } @conference {40391, title = {The use of farm computers in animal management}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {115-118}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A dose-response curve for ovulation rate in Merino ewes homozygous for Booroola FecB gene was generated by injecting PMSG at dose rates increasing from 3300-1200iu in 100iu increments (n=8-13 per group). PMSG was administered, at a concentration of 1000iu/ml in a saline carrier, as a single injection 15 days after the withdrawal of intravaginal progestagen sponges. An additional 20 control ewes were injected with 1ml of saline. The mean lifetime ovulation rate (LO) was calculated for each ewe from data collected for up to three years prior to the study. In individual ewes, a "response" to PMSG was defined as an ovulation rate at least 4 standard deviations (flock mean SD 0.87) greater than LO. Using this arbitrary value, no animals responded at doses below 500iu and less than 50\% responded at 500 and 600iu. Above 800iu 75-100\% of ewes in each treatment group responded. When log ovulation rate was regressed against dose of PMSG there was a highly significant dose-response (P<0.001, RSD 0.512). Using a subjective assessment of changes in ovarian morphology it was observed that >/=70\% of ewes given 1000iu or more of PMSG showed over- stimulation of one or both ovaries. There was no apparent carry-over effect of PMSG at the oestrous cycle following treatment. }, issn = {1176-5283}, author = {Nuthall PL} } @conference {40398, title = {The use of protein polymorphism and DNA fingerprinting to solve complex pedigree problems in deer - Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {143-144}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {In a study of seasonality of reproduction, 4 pubertal red deer hinds were monitored for live weight and plasma hormone concentrations from December 1987 to October 1988 (i.e. 12-22 months of age). On 7 occasions blood samples were collected every 20 minutes for 4 h to monitor secretion of luteinising hormone (LH) and response to an i.v. injection of 2 }, issn = {1176-5283}, author = {Tate ML and Dodds KG and McEwan KM and Buchanan FC and Swarbrick PA} } @conference {40370, title = {The value of ultrasound in assessing the leg muscling of lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {33-36}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Faecal worm egg counts (FEC) were recorded on 779 lamb progeny in a performance recorded flock in Northland during summer-autumn 1990 to determine breed and sire variations. Progeny were ram lambs born in 1989 representing 4 Perendale, 4 Romney and 7 cross-bred sires. The study protocol was that the lambs remained undrenched until the mean FEC of representative {\textquoteright}monitors{\textquoteright} reached 1000-1500 eggs/g. Then all stock were faecal sampled, drenched and the protocol repeated. Full samplings occurred on 12 February (FEC1) and 12 March (FEC2). All animals grazed as one mob throughout the programme. There were significant variations within and between breeds in FEC. Perendale and Crossbred lambs had significantly lower faecal egg outputs than Romneys on both occasions (FEC1=3560, 4073, 4757; FEC2=2535, 3242, 3737, respectively). One possible explanation of the results is that Perendales selectively avoid parasite contamination on pasture through differences in grazing behaviour. Alternatively, they may have consumed less pasture and larvae because they were lighter. If these are not the cases these data suggest that Perendales in this flock may be more resistant to internal parasites. }, issn = {1176-5283}, author = {Ward BG and Purchas RW and Abdullah AY} } @conference {40432, title = {Wool growth and elemental composition}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {281-284}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Six Merino wethers were used to graze six box-grown genotypes of subterranean clover in a Latin square design. Each animal was offered 2 replicates of each genotype and permitted to graze 70\% of the sward on offer. The amount eaten was recorded at each grazing and video recordings were used to record each sheep{\textquoteright}s grazing behaviour. There were genotype differences in the rate of intake of fresh feed (g/min) with Clare (79.3 g/min) being eaten faster than the other genotypes while Trikkala (67.1 g/min) was eaten faster than both Geraldton (53.0 g/min) and Dinninup (54.9 g/min). Similarly bite rate and dry matter (DM) per bite (bite weight) were significantly related to genotype. With Dinninup the rate of intake and DM per bite were less than expected from the measured sward characteristics while differences in sward height accounted for most of the differences recorded with Clare (20 cm tall) and Geraldton (8 cm tall). The results indicate differences in the intake response of sheep to different genotypes of subterranean clover. Possible reasons for these differences are discussed.}, issn = {1176-5283}, author = {Lee J and Bray AR and Grace ND} } @conference {40416, title = {Wool production from wet and dry ewes on southern North Island hill country}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {217-220}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Two trials were conducted which examined the effect of duration of CIDR}, issn = {1176-5283}, author = {Betteridge K and Lambert MG and Devantier BP and Budding PJ and Costall DA and Fletcher RH} } @conference {40312, title = {alpha-Lactabumin - The milk manipulator{\textquoteright}s dream}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {211-218}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The importation of 100 alpacas from Chile in 1989 has enabled some preliminary observations to be made on the performance of these animals under farming conditions in Otago. After one year the adult female liveweights (70.8-72.8 kg) exceeded that of alpacas farmed in South America. Cria showed high growth rates (176 gm/day) to weaning at 5 months of age. Sixty two cria were born and their survival to 7 months of age was high (92\%). Only 22\% of females had cria following spring mating but a more successful autumn mating resulted in 61\% pregnant. Adult females clipped 1.7 kg and males 2.8 kg of fibre. The fibre diameter from females averaged 28.8 microns and from males 30.6 microns. Nine month old cria clipped 1.7 kg of fibre with a mean diameter of 23.4 microns. These preliminary data indicate that alpacas are adapting well to this new environment, but as in South America, there are problems of low fertility. }, issn = {1176-5283}, author = {Wilkins RJ} } @conference {40319, title = {Alternative and supplements to pasture for growing lambs in winter}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {249-254}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The Wairunga flock was established in 1956. It has since been selected for production traits and, recently, also for {\textquoteright}disease{\textquoteright} traits (resistance to footrot, dags and internal parasites). Records of weaning weight, autumn weight, winter weight, faecal egg count (FEC) and fleece weight have been collected on ewe and ram lambs from the 1987- born crop onwards, in a management programme which involved withholding anthelmintic drench for a monitored period in autumn. Dag scores have also been taken at the time of faecal sampling from the 1988-born crop onwards. Experiences already show that there is keen interest from ram buyer clients in 2-tooth rams that have grown without a drench. Results show significant potential savings in numbers of drenches on weaned lambs, and large differences among sire groups in the parasite susceptibility of progeny groups. Because of the need to withhold drenches, a major change in the whole concept of ram breeding and performance testing will be required by ram breeders and their clients before much progress can be made in breeding for resistance to internal parasites. }, issn = {1176-5283}, author = {Bray AR and Moss RA and Burton RN} } @conference {40350, title = {Analysis of lamb schedules and relative economic values of lean and fat}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {405-410}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A model is constructed to give the probability of conception conditional on the previous calving date in a herd of Angus beef cows. The parameters of the model are the anoestrous period following calving, the length of the oestrous cycle (both independent random variables having normal probability distributions), and the conception rate at each oestrus occurring within the mating period. The anoestrous period is assumed to depend linearly on the calving date. The observed calving distributions of 10 consecutive years in a beef cow herd were used in the model to estimate the optimum herd conception rate for the parameters "anoestrous period" and "regression between anoestrous and calving date". A conception rate at each oestrous during mating of 0.7 was assumed. Anoestrous period was constrained by experiment to between 50 and 90 days. The regression between anoestrous and calving date was constrained to between 0 and -0.5 days per day. These constraints constituted a non-linear programming problem. The optimum values for the anoestrous period under these conditions lay between 60 and 70 days for the 10 years of data analysed. It is shown that the anoestrous period has very little effect on herd in calf rate below 70 days in the calving distributions considered. It is suggested that resources should not be used to reduce the anoestrous period below 70 days. The anoestrous period tended to have a greater effect on herd conception rate if less than 90\% of the herd had calved before day 40 of the calving period, and the anoestrous period was longer than 70 days. Beginning mating 7 days earlier generally increased the herd conception rate by about 1\% over the 10 years considered. }, issn = {1176-5283}, author = {Waldron DF and Clarke JN and Rae AL} } @conference {40315, title = {Antibody-mediated enhancement of growth hormone activity: application to animal production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {227-234}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {In addition to advantages offered to the lamb trade by the new sheep breeds they also offer opportunities to the wool industry. The influence of new breeds imported by Lamb XL on lamb and hogget wool production and characteristics was examined for Texel, Oxford Down, Whiteheaded Marsh and Finnish Landrace crossbreds compared with Romneys. Fleece weights were similar for the Oxford Down, Whiteheaded Marsh and Romney crosses but Texel crosses had a 12\% reduction in hogget fleece weight. Texel and Oxford Down cross hoggets produced wool with high bulk and staple strength compared to the Romney cross hoggets. These characteristics are currently of special interest in the wool industry, with premiums existing for bulk and anticipated in the near future for staple strength. There were no practical differences in other wool characteristics between Romney, Texel, Oxford Down and Whiteheaded Marsh cross hoggets including fibre diameter, yield, colour, vegetable matter contamination and position of break. Finnish Landrace crosses produced lighter, finer fleeces. However half Finnish Landrace crosses are unlikely to be used in farming systems and reductions in fleece weight will be lower in the anticipated quarter or eighth Finnish Landrace crosses. Lamb and hogget wool production and characteristics from the exotic crossbreds compare favourably with New Zealand Romneys and offer increases in wool production compared to traditional terminal sires. }, issn = {1176-5283}, author = {Aston R and Holder AT and Rathjen DA and Trigg TE and Moss BA and Pell JA} } @conference {40322, title = {Are yearling heifer mating and more productive beef cow breeds a worthwhile use of winter feed?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {265-270}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A computer software package (REVGAIN) is being developed to integrate closely with Animalplan. It assists breeders and their advisers to derive relative economic values and selection criteria to suit their breeding programme. For farmers buying flock rams REVGAIN derives relative economic values for their individual commercial flock, and hence the sort of breeder from which to buy rams. Using specific production levels, prices, and costs for the producers{\textquoteright} or breeders{\textquoteright} situation, together with the corresponding Animalplan phenotypic and genetic parameters, the software calculates relative economic values that will lead to maximum economic progress in the breeding goal. It also estimates the change in each character that will occur from a standard amount of index selection. By comparing different economic outcomes from changing product prices, physical inputs or genetic responses, users derive the policy that is most appropriate to their particular situation. }, issn = {1176-5283}, author = {McMillan WH and McCall DG} } @conference {40336, title = {Artificial insemination and synchronised natural breeding in Red deer}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {327-332}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The cold resistance of cashmere wethers in which cashmere had been harvested by shearing the while fleece, or by removal of down only through repeated hand combings, was studied at two ambient temperatures (10 C and 30 C) and two wind speeds (0 and 6 km/hr). Heat production was calculated from oxygen consumption measured over 24 hours, in 8 pairs of goats fed at 1.25 times maintenance level. In shorn goats, heat production increased by 50\% during exposure to 10 C (compared with 30 C) while the corresponding increase for combed goats was only 9\%. The interaction between the effects of the low temperature and the methods of fibre removal was significant (P<0.001). Similarly at 10 C, exposure to a wind of 6km/hr caused a larger increase in heat production in shorn goats than in combed goats; the interaction was significant (P<0.05). The data show clearly that the combed goats were considerably more resistant to cold conditions that the shorn goats. }, issn = {1176-5283}, author = {Fennessy PF and Mackintosh CG and Shackell GH and Whaanga AJ} } @conference {40300, title = {Artificial insemination using the buck effect to partially synchronise cashmere does}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {143-146}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract available }, issn = {1176-5283}, author = {Moore RW and Hall DRH} } @conference {40311, title = {Autocrine control in milk production and mammary development}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {203-210}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Currently less than 20\% of the lambs slaughtered in New Zealand each year for export are killed in the five months from July to November. The feeding of high grain content diets in feedlots, grain supplements at pasture, maize silage or forage legumes to increase lamb supply over this period is discussed. Grain-based feedlot diets, supplements of pea grain fed at pasture and lupin and tick bean forage produced lamb liveweight gains of 200 to 300 g/d, that compare with gains of up to 150 g/d expected at pasture. Effects on carcass leanness and meat taste were generally small. Although usually more expensive than pasture, other feeds can be at least as profitable when pasture is in short supply premiums are paid for lambs supplied in winter and spring. }, issn = {1176-5283}, author = {Wilde CJ and Addey CVP and Knight CH and Peaker M} } @conference {40351, title = {Best linear unbiased prediction for across-flock/year breeding values}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {411-416}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Three pasture types (Wana cocksfoot, Roa tall fescue, and Ruanui perennial ryegrass/Huia white clover) were ranked on short term rates of intake, measured using boxed turfs indoors and short grazing periods at pasture. In the first experiment 12 turfs of each pasture type were offered to each of 3 heifers indoors in a latin square design. In a second experiment at pasture, 3 heifers grazed each pasture type for a day again in a latin square design. Intake rate in the first experiment was estimated from pre- and post- grazing weight of turfs with correction for respiratory and evaporative weight loss. At pasture in the second experiment intake rate was the difference between pre and post grazing weight of the heifers corrected for insensible weight loss. Rankings of grass cultivars indoors and outdoors were similar even though animal and sward maturity differed. Intake rate of ryegrass/white clover was lower both indoors and outdoors than for Roa tall fescue or Wana cocksfoot (indoors 103 vs 131 and 148, and outdoors 65 vs 161 and 102 mgDM/kg/W/min). Bite weight (2.1 vs 2.7 and 2.8 mgDM/kgW) and bite depth (5.9 vs 6.4 and 6.7 cm) for ryegrass/white clover indoors were lower than for tall fescue or cocksfoot. Allocation/intake relationships derived for ryegrass/white clover may not be applicable to other pasture species. }, issn = {1176-5283}, author = {Garrick DJ} } @conference {40275, title = {Breeding for disease resistance - some historical perspectives, problems and prospects}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {1-14}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Red deer stags received a series of immunisations against LHRH with the aim of suppressing the reduction in growth normally associated with the rut, but without affecting carcass fatness. Immunisations commenced at 10 months of age (September), including a series of either early (October) or late (November) booster immunisations. The immunisations produced antibodies to LHRH and delayed testes enlargement, with effects being greatest during summer (December- January). Liveweight changes were similar in the late booster and control groups. Mean liveweight declined during the rut (April and May) in all groups. However, stags that received the early booster were significantly heavier (P<0.05) than the other two groups in October (11 months old) and from February to October of the following year (15-23 months old). Twenty four hours prior to slaughter (October), mean (}, issn = {1176-5283}, author = {Baker RL} } @conference {40344, title = {Brief Communication - Susceptibility of the breeding ewe to parasitism}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {375-378}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Genetic and phenotypic parameters were estimated for some components of cashmere production using data obtained from goats born in 1987 and 1988 from flocks participating in a sire reference scheme. A total of 33 sires and 841 progeny were included in the analysis. Heritability estimates of weaning and yearling liveweights from univariate restricted maximum likelihood (REML) analyses were 0.14}, issn = {1176-5283}, author = {McAnulty RW and Familton AS and Sykes AR} } @conference {40338, title = {Bulk and its structural basis: A review}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {339-346}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A case farm study of a once-bred heifer system on hill country using a spreadsheet simulation model was undertaken. Results of the feed budge and financial data of the once-bred system were compared with bull beef, 18 month heifer finishing and traditional breeding cow policies. The once-bred heifer system generated a gross margin of $48.26/s.u. compared with $42.50/s.u. for a traditional breeding cow breeding system, $31.70/s.u. for the 20 month heifer finishing and $52.80/s.u. for a bull beef system. The once-bred heifer system produced 314 kg carcass/ha, the breeding system cow 197 kg carcass/ha, the 20 month heifer system 354 kg carcass/ha and the bull beef system 433 kg carcass/ha. The major factor affecting the profitability of the once- bred heifer system was schedule price. The best match of animal requirements and pasture growth for the once-bred heifer system was shown to occur for an October calving. This study suggests that sheep and beef farmers with traditional beef cattle policies could increase productivity by adopting a once-bred heifer beef production system. }, issn = {1176-5283}, author = {Stobart RH and Sumner RMW} } @conference {40331, title = {Comparative wool production of Texel, Oxford Down, Finnish Landrace and Romney sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {303-308}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Two lines of Perendale sheep selected for an against loose wool bulk as yearlings at hogget shearing were established at Whatawhata Research Centre in 1987. Each line consists of approximately 100 mixed age breeding ewes. At ewe hogget shearing in 1989 loose wool bulk of the selection lines differed by 5.2}, issn = {1176-5283}, author = {Dobbie JL and Sumner RMW and Clarke JN and Speedy PM} } @conference {40332, title = {A comparison between lamb drafters and the Phillips Fat Displacement Meter (PFDM) for predicting GR, hot carcass weight and class in live lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {309-314}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A fine wool index selection flock (I) was established by screening the Tara Hills Merino flocks in 1988 and 1989. The flock of 200 breeding ewes was formed with equal numbers of four age groups born in 1984 to 1987. A randomly sampled 160 ewes from the same population served as the Control (C). The greasy fleece weights of the I flock were 8.3\% (P<0.001), 6.8\% (P<0.001) higher than that of C flock in 1988 and 1989 respectively. Spring live weight (P<0.05) and yield (P<0.001) were significantly higher while fibre diameter (P<0.001) was significantly lower for I. Progeny hogget fleece weight, live weight and fibre diameter, however, differed insignificantly between flocks. }, issn = {1176-5283}, author = {Kirton AH and Uljee AE and Mercer GJK} } @conference {40330, title = {Computer software to increase the efficiency of the New Zealand sheep industry}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {299-302}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Loose wool bulk has been identified as a desirable objective characteristic associated with superior end-product performance in many of the present uses of wool. These are specifically, improve appearance retention of carpets and improved insulation of knitting yarns and loose wool batts. Breeds have been shown to differ in their ability to produce high bulk wools. Loose wool bulk is strongly inherited in the adult fleece, it is not however expressed in the lamb fleece and subsequently cannot be used as a selection criteria until hogget shearing. Fibre crimp appears to be the major factor associated with bulk. Crimp formation in Merinos is related to follicle structure, cell mitotic activity and cellular differentiation within the follicle bulk resulting in the production of different cortical cell types. At this time it is not known if a similar situation applies to crossbred wool type sheep. The identification of a suitable measurable structural characteristic would facilitate the selection of high loose wool bulk crossbred wool type sheep at a young age. }, issn = {1176-5283}, author = {Binnie DB and Clarke JN and Cooke AC and Johnson DL and Rae AL} } @conference {40328, title = {Dairying in the south}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {295-296}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Synchronised breeding systems involving 290 red deer hinds were investigated in 5 experiments with fixed-time laparoscopic artificial insemination (AI) following a synchronised oestrus and in 1 experiment with synchronised natural breeding. Experiment 1 involved an investigation of the potential for twinning; hinds were treated with PMSG and inseminated before (March 1) or during (April 12) the normal breeding season, with 29 and 40\% respectively having multiple ovulations. There was no effect of AI date on pregnancy rate (0.80 and 0.71 respectively) but a greater proportion of hinds which had multiple ovulations. There was no effect of AI date on pregnancy rate (0.80 and 0.71 respectively) but a greater proportion of hinds which had multiple ovulations and had not been lactating in the previous season were twin- pregnant than hinds which had been lactating (0.19 and 0.62, P<0.05). In other experiments AI was performed using red (R; n=70), Canadian wapiti (CW; n=59) or CW x R hybrid (n=11) frozen-thawed semen with pregnancy rates of 0.67, 0.66 and 0.82 respectively. Fresh Pere David{\textquoteright}s deer x R hybrid semen gave a pregnancy rate of 0.61 (n=31). A pregnancy rate of 0.84 was recorded for the synchronised natural mating of (CW x R) males with red females (n=49). Overall 3\% of the R pregnancies and 9\% of the hybrid pregnancies failed to reach terms. }, issn = {1176-5283}, author = {McDonnell AM} } @conference {40333, title = {Development of a self-drafting system for oestrus ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {315-318}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The effect of nutrition on fibre growth cycles and medullation in skin of Angora goats was investigated by microscopy of transverse sections of hair follicles. Samples of skin and fleece were taken at regular intervals between August 1989 and August 1990 from non- reproducing does fed either maintenance (MPA) or ad libitum (HPA) pasture allowances. There were no differences in follicle activity between nutritional treatment groups for any of the 11 sample dates. Primary follicles grew and shed their fibres seasonally, with the main growth period from September to May and the mean nadir of 26}, issn = {1176-5283}, author = {Matthews LR and Uljee AE and Bremner KJ and Painting AM and Cate LR and Smith JF} } @conference {40281, title = {DNA variation among seven New Zealand sheep breeds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {47-54}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Karyotype analysis, used for screening chromosomal anomalies in humans and livestock, is being evaluated as a means of identifying sheep carrying the Booroola fecundity gene. This has involved comparing the chromosomes of metaphase spreads from animals heterozygous for the Booroola gene (FecB+) to screen for numerical or physical abnormalities between the chromosome pairs using Giemsa (GTG) banding. A number of anomalies have been observed from 18 of 3 FecB+ rams and 4 FecB+ ewes. The anomalies were spread throughout most chromosomes, but none were present in all karyotypes. No alteration in chromosome number was observed. These preliminary results suggest that the Booroola mutation is not the result of a major chromosomal alteration. }, issn = {1176-5283}, author = {Sise JA and Montgomery GW and Hill DF} } @conference {40324, title = {The effect of cow age and management of winter liveweight gain, liveweight at calving and subsequent effects on dairy production in a seasonal supply herd}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {277-282}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A trial was undertaken in which 11 meat company lamb drafters estimated the GR carcass fatness, hot carcass weight and carcass class on 26 live lambs. In addition the Phillips Fat Displacement Meter (PFDM) was used to estimate GR fatness these live animals. The average hot carcass weight of the lambs was 21.9kg and mean GR on the left and right sides were 14.2mm and 14.5mm respectively. The best two drafter estimates correlated more highly (0.89 and 0.83) than the PFDM (0.81) with lamb carcass GR (mm) on the left sides of these carcasses. On the right sides these two drafters correlations were respectively 0.91 and 0.84 while the PFDM correlation was 0.85. The correlations of the poorest drafter were 0.62 and 0.57 for the left and right sides, respectively. While the best drafters were accurate in ranking live lambs for fatness, in absolute terms all drafters underestimated GR on average by 2.2mm whereas the PFDM underestimated by 1.1mm on the left side and 0.8mm on the right. So for actually drafting lambs for slaughter, the PFDM is less likely to select lambs in the penalty payment ranges, or is more likely to select lambs before they reach these penalty fatness levels than the company drafters. These results highlight the need for drafter training courses with feedback on their results. On average the drafters underestimated carcass weight by 4.0kg. }, issn = {1176-5283}, author = {Thomson NA and Barnes ML and Prestidge R} } @conference {40305, title = {Effect of high and sustained zinc supplements on trace element metabolism in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {173-178}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Alpha-lactalbumin (alpha-lac) is a component of the enzyme complex lactose synthetase which plays a key role in the regulation of lactose synthesis and milk water secretion. Ribozyme mediated manipulation of alpha-lac expression should enable more precise elucidation of its physiological significance and may lead to the development of transgenic animals. Five ribozymes and controls targeting different regions of the alpha-sac gene have been synthesised and cloned. In vitro ribozyme analysis involved the incubation of in vitro transcribed alpha- lac and ribozyme RNA. The rate of ribozyme cleavage in vitro was influenced by temperature, MgC1 2 concentration, length of antisense flanking sequences and region of the alpha-lac gene targeted. In vivo ribozyme analysis was carried out in the T7/vaccinia expression system using C127I mouse mammary cells. This system utilises the powerful bacteriophage T7 RNA polymerase which is expressed when cells are infected with a recombinant vaccina virus. Gene constructs, cloned into vaccina plasmids downstream from a T7 promoter are transfected into the cells and are transcribed and translated at very high levels. Using this system we have identified that ribozymes that targeted exposed stem loops and the 3{\textquoteright} end of the gene down regulated the level of alpha-lac RNA to 10-20\% of the controls. Similar reductions in expression of alpha-lac protein were observed for these key ribozymes, but in addition a full length antisense was equally as effective. The expression of these ribozymes in transgenic mice will enable evaluation of their effectiveness to influence lactose synthesis and milk water secretion. }, issn = {1176-5283}, author = {Lee J and Grace ND and Martell S} } @conference {40339, title = {Effect of selecting Perendale hoggets for loose wool bulk on fleece characteristics and wool end-product performance}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {347-352}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Hoggets from the Massey University fleeceweight-selected (FW) line were previously shown to have lower sulphur (S) concentrations in midside wool than control (C) hoggets at 14 months of age. This study involved two experiments. The first examined wool S concentrations at different body positions in 14-month hoggets and the second examined midside wool S concentration and blood parameters in young lambs. In Experiment 1, 16 FW hoggets and 16 C hoggets were wool sampled at 11 positions over the body. The wool S concentration of FW hoggets was found to be significantly (P<0.01) lower than that of C hoggets (2.77\% vs 2.94\%). Discriminant analysis was used to classify hoggets to their respective lines based on wool S measurements. The combination of sites which most correctly classified the hoggets was the midside plus base of the tail. In the Experiment 2, 40 FW and 40 C lambs were wool sampled on the midside at 28 day intervals from 21 November (1 week before weaning) to 13 February. FW lambs had significantly (P<0.05) lower midside wool S concentrations of urea, but not of creatinine, than C lambs. Results suggest that wool S concentration and plasma urea concentrations may be useful genetic markers for high fleece production but that the ability to discriminate between animals of high versus low genetic merit for fleece weight on the basis of wool S will depend on the sampling position and age of animals. }, issn = {1176-5283}, author = {Sumner RMW and Maddever DC and Clarke JN} } @conference {40355, title = {The effect of sodium bicarbonate on yield and composition of milk from grazing cows in early lactation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {437-442}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied }, issn = {1176-5283}, author = {Carruthers VR and Bryant AM} } @conference {40307, title = {The effect of three allowances of red clover on Red deer fawn growth and liveweight change in lactating hinds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {185-188}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The binding of monoclonal antibodies (MAbs) of predetermined specificity to growth hormone (GH) can result in significant enhancement of the biological activity of the hormone in vivo. The topographic region on GH associated with the enhancement phenomenon has been localised to two proximate sites on adjacent loop regions by extensive peptide synthesis (sequences: 35-53 and 134-154). The application of these observations of GH and (ii) increased production parameters following administration of particular antibodies. The latter aspect has now been demonstrated in a number of animal models by the passive vaccination of animals with purified anti-peptide antisera or monoclonal antibodies. Production parameters affected in such experiments include growth rate, fat metabolism, diabetogenic activity and lactation in ewes. At the present time, it has been shown that peptide sequence 134-154 will elicit up to 80\% high titre, immuno- positive responders in sheep. Monitoring the growth rate and other production parameters of lambs vaccinated with sequence 134-154 indicates improved growth and total protein characteristics. These observations, in conjunction with the development of methodologies for effective autoimmunization of animals, may provide a basis for the design of peptide vaccines to improve animals, may provide a basis for the design of peptide vaccines to improve animal production. }, issn = {1176-5283}, author = {Niezen JH and Barry TN and Hodgson J and Wilson PR and Holmes CW} } @conference {40303, title = {The effect of varying leafy sward height and bulk density on the ingestive behaviour of young deer and sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {159-166}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {In dairy animals, the development and secretory activity of each mammary gland in the udder is regulated independently by local mechanisms sensitive to the frequency and efficiency of milk removal. Acute regulation of milk secretion occurs through autocrine inhibition by a secreted milk constituent, which may act by modulating the sensitivity of the tissue to circulating hormones. Sustained changes in milking frequency or efficiency are associated with modulation of secretory cell differentiation and, ultimately, the number of secretory cells. Elucidation of these local intra-mammary mechanisms offers the prospect of controlling milk secretion in a novel and more specific manner than has hitherto been possible. }, issn = {1176-5283}, author = {Mitchell RJ and Hodgson J and Clark DA} } @conference {40290, title = {Effects of daily larval challenge on the performance of breeding ewes from late pregnancy to post weaning - Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {95-96}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A CIDR was inserted into 72 ewes which were either early in the cycle (E; days 1-3), at mid cycle (M; days 7-9) or late in the cycle (L; days 13-15). Half of the ewes received either 0 or 300 IU of pregnant mares{\textquoteright} serum gonadotrophin (PMSF) at the start of superovulation treatment. M ewes had two thirds as many ovarian surface follicles >1.5 mm diameter compared to E and L ewes (8.8 vs 13.6 vs 13.0; P<0.001). M ewes had approximately two thirds as many ovulations present 8 days later compared to E and L ewes (5.1 vs 7.7 vs 7.7; P<0.05). For ewes receiving 300 IU of PMSG as well as FSH, there was a significant regression of follicle number on ovulation rate (b=0.73}, issn = {1176-5283}, author = {McAnulty RW and Familton AS and Sykes AR} } @conference {40343, title = {Effects of fasting and an opioid antagonist on food intake in lambs infected with intestinal parasites}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {371-374}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A divergent selection experiment with Romney sheep, using plasma concentration of IGF-1 measured 4 weeks after weaning as the selection criterion, was initiated in 1986. From 111 ram lambs born and reared as twins, 4 with the highest level of IGF-1, 4 with the lowest level and 4 selected at random were used to create three lines (high, low and control). Each ram was randomly mated with 25 ewes. Data from 1986 (number of lambs=111), and two F1 generations (1988, n=241 and 1989, n=151) are presented here. Analysis of variance showed that date of birth, age of dam, rearing rank, and sex significantly contributed to variation in plasma levels of IGF-1. Expression of variation in plasma IGF-1 between years appeared to be influenced by variation in pasture supply. Residual correlations between IGF-1 levels and production traits were positive but of variable magnitude (weaning weight, 0.14 to 0.43; post-weaning growth rate, -0.07 to 0.24; fleeceweight, 0.27). Based on the selection differential generated by initial screening of rams and the average divergency between the high and low lines, realised heritabilities of 0.22 and 0.27 were obtained for plasma IGF-1 concentration in 1988 and 1989, respectively. }, issn = {1176-5283}, author = {Dynes RA and Poppi DP and Barrell GK and Sykes AR} } @conference {40283, title = {Effects of immunisation against LHRH on body growth, scrotal circumference, and carcass composition in yearling Red deer stags}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {63-66}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Mammary tissues from virgin, prepartum and lactating ewes were examined by in situ hybridisation with a 35S labelled cRNA probe derived from the bovine alpha-lactalbumin gene. Expression of alpha- lactalbumin was absent in the virgin udders. In the pregnant gland, alpha-lactabumin expression was found in some secretory alveoli but not in others, even though they appeared histologically similar, containing milk or colostrum and fat globules. Fully lactating ewes have several levels of alpha-lactalbumin expression. In secretory epithelium, it was high in collapsed thick walled lactating alveoli, slightly less in distended thin walled lactating alveoli with homogeneous contents and absent from alveoli containing an abundance of large fat globules. Beta-cytophasmic actin expression was the reverse of this. These observations are intriguing and suggest a number of hypotheses. Firstly; that alpha-lactalbumin gene expression is linked to the long term secretory activity of cells and drops off once cells are resting or regressing. Secondly; that alpha-lactalbumin gene expression is highest in those alveoli which are "filling up" and lowest in those which are full or have just been milked out. That is, there are cyclical variation in expression. And thirdly; that there is distinct compartmentalisation in the lactating gland, and synthesis of alpha- lactalbumin mRNA (and the protein?) occurs in cells which synthesise little fat. }, issn = {1176-5283}, author = {Freudenberger DO and Wilson PR and Purchas RW and Barry TN and Moss BA and Trigg TE} } @conference {40309, title = {The effects of once daily milking as a management practice in late lactation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {191-196}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Five goats were milked hourly for 43 h on two occasions, on one occasion receiving injections of growth hormone (GH; 15 mg S.C.) after 4 and 28 h of the milking period and on the other occasion were untreated. Blood samples were taken before each milking, the latter facilitated by intravenous injection of oxytocin (100 m i.u.). Milk yield began to rise 4-5 h after the injection of GH and continued to rise for a further 8-9 h until a level of production 18\% above the pre-treatment yield was achieved. Following the second injection of GH the yield increment was reduced such that by the end of the experiment the yield increase was 24\%. In one goat the milk yield response was not sustained and these data were excluded from the above calculations. Plasma insulin-like growth factor-I (IGF-I) and insulin concentrations increased in a similar time-course to the change in milk yield following GH treatment but were relatively constant in control experiments. IGF-I and insulin content of plasma was approximately doubled by GH treatment by the end of these experiments. }, issn = {1176-5283}, author = {Lynch GA and Hunt ME and MacKenzie DDS} } @conference {40310, title = {The effects of oxytocin and bovine somatotropin on production of cows milked once a day}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {197-202}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Milk from normally lactating goats contains on average 11 ng/ml IGF-I and 106 ng/ml IGF-II, as determined by specific radioimmunoassay. The present study was an attempt to determine whether IGFs in milk could have originated from the blood. 125 I labelled IGF-I or IGF-II was infused directly into one gland via a pudic arterial catheter for 60 mins and their appearance in milk followed for 720 min. A total of 5.2\% of [125 I]IGF-I infused and 10.0\% of [125I]IGF-II was recovered from milk from both glands. Radioactivity consisted of TCA precipitable material, which eluted from Sephacryl S-200 as free and protein-bound IGF, and TCA soluble material which probably represents degraded products of the peptides. The amount and time course of secretion of TCA soluble radioactivity in milk from both glands was similar, indicating degradation of infused peptide at textra-mammary sites. Maximum specific activity in milk from the infused gland occurred at 80-120 min for IGF-I and 120 min for IGF-II and was 2.5 fold higher than milk from the non-infused gland. The lower milk/plasma ratio for immunoreactive IGF-I compared with 125I labelled IGF-I suggests all milk IGF-I might be derived from the circulation whereas similar calculations with IGF-II suggests only 78\% of milk IGF-II could be accounted for by its transfer from blood. }, issn = {1176-5283}, author = {Carruthers VR and Davis SR and Norton DH} } @conference {40304, title = {The effects of season and herbage mass on the nutritive value of prairie grass cv. Grasslands Matua and perennial ryegrass}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {167-172}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The properties of the milk serum protein alpha-lactalbumin are reviewed with special emphasis being placed on its central role in determining the lactose and water content of milk. Much circumstantial evidence suggests that artificial depression of alpha-lactalbumin synthesis should decrease lactose synthesis and that this will, in turn, decrease the water content of milk. Experimental evidence indicates, however, that patterns of alpha-lactalbumin gene expression in lactating ovine and bovine mammary tissue are complex and we should be cautious in making such predictions. Studies with transgenic mice expressing either elevated or depressed levels of alpha-lactabumin will be required to settle this question. In the meantime, a promising line of research is the investigation of dairy cattle carrying variant alpha-lactabumin genes. It is possible that correlations will be found between some of these variants and both the water content and protein yield of milk. Conceivably, selective breeding of cattle carrying variant proteins may prove a more practical means of altering alpha-lactalbumin synthesis than current transgenic techniques. }, issn = {1176-5283}, author = {Rugambwa VK and Holmes CW and Chu ACP} } @conference {40356, title = {Effects of the digestibility of hay on milk production by cows grazing on restricted pasture}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {443-446}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Two groups of 12 cows were fed and managed identically throughout the whole lactation, except that one group was milked twice daily, whereas the other group was milked only once daily. The cows were aged 3 years and older, and included 6 pairs of identical twins. Yields of milk, fat and protein were: 4320 and 2810 kg milk ; 208 and 144 kg fat; 162 and 110 kg protein for the twice and once daily groups respectively and the differences were significant. However in three pairs of twin cows, once daily cows produced more than 90\% of the yield produced by their twice daily twin mates. Lactose concentrations were significantly higher for the twice daily group, 5.05 and 4.82\% lactose. Somatic cell counts were significantly lower for the twice daily group throughout lactation, even though there appeared to be no difference in the incidence of infection measured at the end of lactation. The twice daily group lost weight and body condition during lactation, even though they appeared to eat slightly more feed than the once daily group which gained weight and body condition. The twice daily group had lower plasma concentrations of glucose during early lactation than the once daily group, but there were no differences in concentrations of calcium, magnesium or Beta hydroxybutyrate between the groups. The results show that although once daily milking does cause significant decreases in yields of milk and its components, some cows were only slightly affected. Selection of tolerant cows, plus appropriate management such as longer lactations and high stocking rates, may offer a useful method of increasing labour productivity and reducing costs of production. }, issn = {1176-5283}, author = {Sangsritavong S and Holmes CW} } @conference {40345, title = {Effects of two methods of fibre removal on the cold resistance of cashmere goats}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {379-382}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Two hundred and six mixed age Angora x Feral (G4) does with a mean fibre diameter of 20.4 microns were randomly mated to three bucks with mean fibre diameter of 18.8 microns (Group 1) and three bucks with mean fibre diameter of 22.2 microns (Group 2) in June 1987. The progeny were shorn at 10 months (August 1988), 16 months (March 1989) and 22 months (August 1989) of age. The fleeces were measured for fleece weight, mean fibre diameter, yield by weight of down, and colour. Down weight was then calculated. The fibre was visually classed according to Mohair-Cashmere Warehouse fibre lines and an economic value put on the fibre. Group 1 progeny were heavier and had finer fleeces and lower down weights than group 2 progeny at all three shearing date. Group fleeces were 0.6, 0.9 and 1.0 micron finer and 71, 86 and 109 grams lighter than Group 2 at the three shearing dates respectively. Fibre diameter increased during the experiment to a greater extent in Group 2 (3.8}, issn = {1176-5283}, author = {Muller S and Holmes CW and Litherland AJ} } @conference {40294, title = {The efficacy of used CIDR devices for synchronisation of oestrus and post-mating treatment}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {111-116}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {An upper limit to the force animals exert to server a bite maybe important in maintaining grazing momentum. Structural strength of accessible pasture components would then determine bite dimensions and weight. Pure perennial ryegrass turfs (surface area 0.1m2 x 0.1m soil depth), were manipulated by clipping to produce 3 pasture heights (5, 10 and 15cm) x 3 sward structures (varying in leaf to pseudostem ratio and bulk density). Six sheep grazed 4 turfs fixed to a force plate of each height and bulk density. Mean peak bite force, bite weight, bite depth, bite area, bite volume and grazed stratum bulk density were calculated. Peak bite force increased with sward surface height but significantly so only between 10 and 15 cm. Sward structure had no effect except on the 5cm sward treatment with the highest grazed stratum bulk density. Bite depth and bite weight increased with pasture height and were not influenced by sward structure at a constant height. Bite area was similar at all sward heights, but decreased as grazed stratum bulk density increased. On short swards, proximity to the ground restricted bite depth and bite weight rather than peak bite force. Low bite weights per newton bite force may constrain bite depth and weight rather than absolute peak bite force. }, issn = {1176-5283}, author = {Smith JF and Konlechner JA and Parr J} } @conference {40299, title = {Evaluation of the feasibility of a juvenile MOET scheme in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {139-142}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {An experiment was conducted at Massey University to measure potential growth rates of fawns and weight changes of hinds during summer, a period when growth is usually limited by adequate feed supply and/or quality. Thirty two lactating mixed age hinds and their fawns (average age 32.9 days) were blocks on calving date and randomly assigned to one of 4 treatments on the Massey deer unit. The treatments consisted of low (LC), medium (MC), or high allowance (HC) of pure red clover (6, 12 or 18 kg DM/hd/day) or 12 kg DM/hd/day of ryegrass/white clover pasture (CON). The corresponding stocking rates were 17.5, 8.7, 5.8 or 7.1 hind/fawn pairs/ha on the LC, MC, HC and CON treatments respectively. Treatments lasted for 61 days from 29 Dec until weaning on 28 Feb. Hinds and fawns were weighed bi-weekly. Weaning weights of the fawns were 51.3, 49.5, 46.7 and 42.8 kg for the HC, MC, LC and CON treatments respectively. This corresponded to fawn average daily weight gain of 461, 433, 380 and 333 g/day respectively. Fawn growth rates and weaning weights were significantly greater on all clover allowances than on the control (p<0.05). HC and MC treatments did not differ but were greater than LC (p<0.05). Hind weight changes followed a similar pattern. Liveweight gains for the hinds was 53, 58, 5 and -52 g/day for the HC, MC, LC and CON treatments respectively. All three allowances of red clover increased weight gain more than CON (p<0.09). HC and MC treatments did not differ but both were greater than LC (p<0.05). }, issn = {1176-5283}, author = {Rangel-santos R and McDonald MF and Wickham GA} } @conference {40342, title = {An evaluation of the New Zealand Wiltshire sheep as a model for studies on the physiology of fibre growth}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {365-370}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {In New Zealand, breeding values have been predicted using the method of selection index (Sheeplan, Beefplan, Animalplan) or variants such as a modified contemporary comparison (Dairy Cattle). Over the last decade, research systems for evaluating beef cattle, dairy cattle, sheep and pigs in New Zealand have increasingly made use of Henderson{\textquoteright}s mixed model equations. In appropriate circumstances, these equations give rise to evaluations which are best, linear and unbiased predictions (BLUP). This review compares and contrasts theoretical and applied aspects of evaluation using selection index and BLUP. An example is used to demonstrate the rationale of BLUP for evaluating animals with records in different contemporary groups such as across flocks or years. }, issn = {1176-5283}, author = {Parry AL and Pearson AJ and Morris R and Still L-A} } @conference {40358, title = {Factors affecting beef finishing efficiency on pasture}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {453-458}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Nineteen cows, diagnosed 30 to 50 days after insemination as conceiving to a double ovulation and ranging in age from 2 to 8 years, were compared for possible signs of pregnancy toxaemia with a sample group of 18 single-ovulating single-pregnant controls, balanced for age. Blood samples were obtained on four occasions, between 2 and 10 weeks before the date when the first cow was due to calve. Blood samples were analysed for ferroxidase, albumin (A), globulin, total protein, the ratio of albumin to globulin, magnesium, beta-hydroxybutyrate (BOH), gamma-glutamyltransferase and serum or whole blood selenium (Se). There were significant differences between single-pregnant and twin-pregnant cows in the concentrations of A, BOH and whole blood Se. Least-squares means were as follows: A, 33.7 and 32.3 g/l; BOH, 0.46 and 1.62 mmol/l; and whole blood Se 887 and 737 nmol/l. The BOH data in particular were useful in identifying cows possible requiring extra veterinary supervision. }, issn = {1176-5283}, author = {McCall DG and Marshall PR} } @conference {40295, title = {Factors influencing the time to onset of oestrus after synchronisation treatment in ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {117-122}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The effect of varying the height and bulk density of the leafy zone of the sward on the ingestive behaviour of six 11 month old Red deer hinds and seven 14 month old Romney ewe hoggets was examined. Deer and sheep, confined to metabolism crates were randomly allocated 21 sward height x density combinations consisting of 7 heights (3-21 cm) x 3 bulk densities (0.19-0.75 mg DM/cm3). The Sorghum bicolor swards were grown in 42 x 30 cm trays and had a deep, stem free leafy zone. The required height of leaf was made accessible to animals by raising or lowering each sward relative to a horizontal grid of fine rods forming 3 cm x 3 cm squares below which animals could not graze. The two lower bulk densities were engineered by snipping out alternate rows, or rows and columns of plants. After grazing for at least 20 bites, bite depth, bite weight, grazed stratum bulk density, bite volume and bite area were calculated. The ingestive behaviour of deer and sheep was very similar in relation to height and bulk density. The positive effect of height on bite depth was on average 11 times as large as the negative effect of bulk density. Height had little or no effect upon bite area, while bulk density had a moderate, negative effect. On average a 100\% increase in height or bulk density respectively resulted in a 64\% vs only 21\% increase in bite weight; reflecting the fact that bite volume increased in relation to H (39\%) but decreased in relation to bulk density (18\%). Thus height was the major determinant of bite volume and bite weight via its influence on bite depth. }, issn = {1176-5283}, author = {Smith JF and Konlechner JA and Parr J} } @conference {40301, title = {Fertility of fallow deer (Dama dama) does following synchronisation of oestrus with CIDR devices or prostaglandin}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {147-152}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {244 cows managed as a single herd were divided into 4 balanced groups. Group A was milked once daily for the last 89 days of lactation, Group B 61 days and Group C 33 days. All cows including a control group milked twice daily, were dried off on the same date. After culling using commercial criteria the remaining 192 cows were milked twice daily in the subsequent lactation. Within one week of imposing once daily milking, daily yield of milk, fat and protein fell by 14.6-11.4\%, 10.6-8.5\% and 8.8-4.0\% respectively when compared to twice daily milked cows. Once daily milking increased protein concentration and somatic cell counts. The relative falls in production observed seven days after the imposition of treatment remained until drying off with consequential reductions in total yield over the period of treatment. Once daily milking reduced the rate of liveweight loss in late lactation. Differences of up to 12.4kg liveweight remained between groups prior to calving in the subsequent lactation, but no differences could be detected after calving. Improve reproductive or productive performance was not observed in the subsequent lactation. }, issn = {1176-5283}, author = {Jabbour HN and Veldhuizen FA and Green G and Langridge M and Asher GW} } @conference {40340, title = {Fleece production responses to Merino fine wool index selection}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {353-358}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Two N.Z. sets of phenotypic and genetic parameters were used to compare expected genetic responses from index selection for an economic breeding objective favouring the lean and penalising the fat content of lamb carcasses. The effect of different economic values for lean relative to fat were examined over the range corresponding to the {\textquoteright}biological{\textquoteright} objectives, weight-adjusted fat and lean growth rate. Particular attention was given to the magnitude and direction of responses in lean and fat. Increasing the economic emphasis on lean relative to fat progressively increased the lean response but was associated with an increasing fat response in an undesirable direction. Different measures of carcass fatness varied in their ability to discriminate among genes affecting fat and lean differentially when included in a selection index along with growth rate, and were superior to eye muscle depth. Good estimates of the relative economic values are required for derivation of optimum selection strategies, especially if indexes of low discriminating power are to be used for selection. }, issn = {1176-5283}, author = {Wuliji T and Dodds KG and Land JTJ} } @conference {40321, title = {Four methods of harvesting cashmere from breeding does}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {259-264}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied }, issn = {1176-5283}, author = {Litherland AJ and Paterson DJ and Hamilton G and O{\textquoteright}Neill K} } @conference {40353, title = {Genetic parameters for New Zealand cashmere goats}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {423-428}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Lack of breeds suitable for commercial dairying is a constraint in Developing Countries (LDCs); however there is some progress. All Latin American Countries have nucleus herds of Holstein or Friesian, compared to 71\% of Asian and 52\% of African countries. The potential for more exports of animals to LDCs is high, but success will depend on support from exporters in their management. Holsteins born in LCDs will have a body weight at maturity about 125 kg (500-550 kg) lower than expected, lactation milk yield will be 30-50\% lower, calving intervals 10-15\% longer, age at first calving 25\% later and duration of herd life .5 to 1.2 parturitions less. This breed needs feeding at least the equivalent of 2.2 multiples of maintenance in TDN. At this level milk yield will average near 6000 kg, calving interval 410-420 d, age at first calving 29-31 mo, fertility will be 1.8 services per conception and herd life 2.6-3.0 parturitions. This should still result in acceptable levels in both biological and economic efficiency. Imbalances in feeding, foot problems, seasonal breeding and milking sanitation appear among the most pressing problems. }, issn = {1176-5283}, author = {Baker RL and Southey BR and Bigham ML and Newman S-AN} } @conference {40306, title = {Goat behaviour patterns in hill country}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {179-184}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied }, issn = {1176-5283}, author = {Greaves LA and Wedderburn ME and Pengelly WJ} } @conference {40278, title = {Greenhouse gas production by ruminants in New Zealand: a serious problem, or just hot air?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {35-40}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {This paper describes five genetic markers from the sheep genome. The polymorphic nature of these new markers, called microsatellites, is due to differences in the number of dinucleotide repeats at each locus. The advantages of these markers compared with other DNA markers are the speed and ease with which individuals can be analysed and the highly polymorphic nature of the loci. The five loci described in this paper had between 4 and 19 loci at each locus, with PIC values ranging from 0.41 to 0.90. It is likely that microsatellites will provide the next generation of parentage test for domestic animals as they are cheaper to perform and simpler to analyse than DNA fingerprints. }, issn = {1176-5283}, author = {Van Gardingen PR} } @conference {40320, title = {Growth, reproduction and fibre production of alpacas imported from Chile}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {255-258}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied }, issn = {1176-5283}, author = {Davis GH and Wuliji T and Moore GH and Bruce GD} } @conference {40277, title = {Impact of potential change in climate and atmospheric concentration of carbon dioxide on pasture and animal production in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {25-33}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Three groups of 10 ewes each were treated with Repromap sponges (MAP), Chronogest sponges (FGA) or Controlled Drug Release devices (CIDR) for 11 days. At withdrawal the delay time until oestrus, LH surge and ovulation was measured. There was no significant difference between the two sponge treatments in mean delay times although FGA treated ewes tended to be less variable in their activity. CIDR treated ewes commenced standing oestrus sooner than MAP and FGA treated ewes (30h vs 42h and 40h respectively P<0.001). Similarly the onset of the LH surge (31h vs 46h and 46h P<0.001) and ovulation (59h vs 69h and 71h P<0.001) occurred sooner in the CIDR ewes compared to MAP and FGA sponges. }, issn = {1176-5283}, author = {Martin RJ and Korte CJ and McCall DG and Baird DB and Newton PCD and Barlow ND} } @conference {40302, title = {The influence of sward structure on peak bite force and bite weight in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {153-158}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The effects of oxytocin and bovine somatotropin (BST) on production of cows milked once a day (OAD) were assessed in late lactation. Seventy four cows were milked OAD for 28 days including 7 days adaptation, 14 days treatment, and 7 days post-treatment. Treatments were OAD controls, OAD plus 5 i.u. oxytocin injected intravenously each day or OAD plus 20 mg BST injected subcutaneously each day. An additional 20 cows were milked twice a day (TAD) throughout the trial. Production of OAD cows averaged 11\% less than that of the TAD controls during the first week of OAD milking. Milk yield was significantly increased by 13\% in BST treated cows but was not affected by oytocin. Cessation of both treatments resulted in a reduction in yield compared to the OAD and TAD control groups. The failure of oxytocin to increase yield was not in agreement with previous results, possibly due to a lower dose rate of oxytocin in the present trial. Increased yields in BST treated cows suggested that udder capacity was not constraining yield and that BST may override the inhibition of milk secretion which occurs with extended milking intervals. }, issn = {1176-5283}, author = {Hughes TP and Sykes AR and Poppi DP and Hodgson J} } @conference {40329, title = {Integrating pastoral venison and beef production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {297-298}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The wool described by the New Zealand Wool Board{\textquoteright}s auction data may be considered to be a vector space defined by axes which are the wool processing parameters. Analysis of this wool vector space gives indications of the relative economic values of the wool properties. Data from 1984 to 1990 has been analysed to give relative economic values and, although short term values vary considerably, there appear to be some longer term trends. Wool bulk as predicted from NZWB type shows a general increase in premium, and wool colour, described by objectively measured yellowness and brightness, has shown increased importance for determining wool price, with brightness taking over from yellowness as the more important of the two. The correlation between parameters in the range of wools offered at New Zealand auctions not only makes it difficult to determine the relative economic importance of the wool properties but limits the range of blend specifications a wool processor can work with. Hence although premiums are not always obvious, it is important to the processor that extremes of wool properties are available to allow the maximum flexibility when making up parcels of wool for processing. }, issn = {1176-5283}, author = {Cowie J} } @conference {40326, title = {Integrating sheep and goats}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {287-290}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {There is a specialised market for lustrous wools. No objective measure of lustre is currently available. Elliott (1986) has suggested, on the basis of the correlation between loose wool bulk (LWB) and lustre (LS) in wools from a wide variety of sources, that measurement of (LWB) and average fibre diameter (AFD) might be a useful indirect selection criterion for lustre. The strength of the above relationships within flocks have, however, not been established. Mid-side samples were taken from complete flocks of ram hoggets (n=390). Clean scoured yield, average fibre diameter and loose wool bulk were determined on all samples. Each greasy sample was independently assessed for lustre on a 7 point scale by three experienced wool appraisers. Within flock correlations between LS and LWB ranged from 0.36 to 0.58 for the best assessor (mean 0.48), much lower than the values (>0.90) obtained in Elliott{\textquoteright}s study. Inclusion of fibre diameter failed to markedly improve the prediction of lustre score. The co- efficient of variation was lower for LWB (4.7\%) and AFD (5.7\%) than for LS (27.8\%). The significance of these results for wool measurement and selection programmes will be discussed. }, issn = {1176-5283}, author = {McCall L and Shaw D} } @conference {40289, title = {Karyotyping Booroola gene carriers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {91-94}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The success of a multiple-ovulation and embryo transfer programme involving five breeds of sheep (Danish and Finnish Texel, Oxford Down, Gotland Pelt, and the White Headed Marsh) was compared across two seasonal periods. Results for the incidence of oestrous, ovulation rate, embryo recovery rate, fertilisation rate, and for the survival rate of the embryos to scanning and lambing in recipient ewes, were compared. The ovulation rate (7.8}, issn = {1176-5283}, author = {Lord EA and Hill DF} } @conference {40314, title = {Lactation in transgenic mice expressing the ovine Beta-lactoglobulin gene}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {225-226}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The efficiency of winter feed use for weaner calf production was compared in a yearling heifer mating system compared to a 2 year old first mating system in traditional and dairy x beef cows. These computer modelling analyses illustrated, with yearling heifer mating compared to 2 year old first mating, that the total weight of calf weaned per unit of winter feed required is increased by only 2\% (Angus dams) and 6\% (Hereford x Friesian dams, HxF). With HxF dams compared to Angus dams, the total weight of calf weaned per unit of winter feed required was increased by 8\% (2 year old first mating) and 13\% (yearling heifer mating). Yearling heifer mating rather than 2 year old first mating within a traditional beef cow breed is questioned, when compared at the same winter feed requirement. The superiority of dairy x beef breeding cows on the basis of calf production from winter feed is confirmed by this analysis. Furthermore, this superiority is maximum when yearling heifer mating is also adopted. }, issn = {1176-5283}, author = {Wilde CJ and Clark AJ and Kerr M and Knight CH and McClenaghan M and Simons JP} } @conference {40308, title = {Lactational Physiology Contract}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {189}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Friesian cows (25 per group) were treated with excipient or recombinantly-derived bovine somatotropin (bST, 25 mg/day) by two- weekly injection of a controlled release formulation for 26 weeks commencing 7 to 11 weeks after calving. Responses in fat yield were significant during weeks 1 to 13 of treatment (spring/early summer) and weeks 21 to 25 (autumn) but not during the intervening dry summer period when pasture allowance was low. Ten randomly-selected cows per group were blood sampled (tail vein, 2 hours off pasture) in weeks 5, 9, 13, 17, 21 and 25 of treatment. Treatment of cows with bST significantly elevated plasma concentrations of immunoreactive bST (12.4 vs 18.5 ng/ml,Pooled se = 0.8 ng/ml, P<0.001) and insulin-like growth factor-1 (IGF-1) (178.5 vs 246.1 ng/ml, Pse = 7.5 ng/ml, P<0.001). Treatment x sampling date interactions were non-significant for plasma levels of both bST and IGF-1, reflecting parallel changes in the concentrations of these hormones across the treatment period. It is concluded that the inability of cows to respond to exogenous bST during periods of low pasture availability does not reflect a diminished IGF-1 response to bST at this time. }, issn = {1176-5283}, author = {Davis SR} } @conference {40323, title = {Lamb and hogget wool production from crosses of new and traditional sheep breeds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {271-276}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Seasonal wool growth and objective fleece characteristics were measured for a group of Texel, Oxford Down (Oxford) and Romney ewes at Hopuhopu Quarantine and Research Station and a group of Finnish Landrace (Finn) and Romney ewes at Flock House Quarantine and Research Station. The ewes were born in 1987 and aspects of wool production measured from November 1988 to August 1990. All breeds exhibited a seasonal pattern of wool growth with a late summer-early autumn maximum and late winter-early spring minimum. The seasonal amplitude of wool growth of the Oxford was less, the Texel similar and the Finn greater than the Romney. Average annual clean fleece weight of the Romney (100) was heavier than the Texel, Oxford and Finn (60, 59, 44 respectively). Oxford and Texel wool was shorter (69, 59 respectively), more bulky (157, 162 respectively) and of a similar mean fibre diameter and brightness compared with Romney wool (100). Finn wool was shorter (70), slightly more bulky (115), finer *(74) and similar brightness compared with Romney wool (100). Texel, Oxford and Finn wools all showed less yellow discolouration (92, 77, 70 respectively) than Romney wool (100). Calculated net wool returns for the Texel, Oxford and Finn ewes were approximately $7, $7 and $11 per ewe per year less than for the Romney. }, issn = {1176-5283}, author = {Newman S-AN and Paterson DJ} } @conference {40291, title = {Localisation of alpha-lactalbumnin gene expression in sheep mammary tissue}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {97-102}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The feasibility of a juvenile MOET (multiple ovulation and embryo transfer) scheme in sheep was evaluated in three trials using 6-7 month-old animals. Ovulation rate was not affected by the dose (1.3 vs 1.1) or the time (1.5 vs 0.9) of PMSG administration, but it was higher in adults than lambs (2.0 vs 1.15, P<0.05) (Trial 1). Adults also showed a higher percentage of animals in heat (89 vs 60, P<0.05) and a higher percentage of eggs recovered (87 vs 56, P<0.05) or fertilised (82 vs 48, P<0.05). In Trial 2, a higher response was achieved with PMSG than FSH-P, Ovagen or PMSG + Ovagen (4.18 vs 1.78, 1.06 and 2.05, P<0.05). GnRH did not affect the ovarian response to gonadotrophins (2.29 vs 2.25, P<0.05). Embryo viability appeared higher in lambs treated with Ovagen alone. A combination of Ovagen + PMSG and with or without GnRH did not improve significantly (P<0.05) the response compared to the administration of PMSG plus GnRH (2.3, 2.8, 2.2 and 2.8 vs 1.7) (Trial 3). The superovulatory treatments involved failed to induce satisfactory ovulatory responses in these prepubertal sheep. }, issn = {1176-5283}, author = {Molenaar AJ and Davis SR and Wilkins RJ} } @conference {40347, title = {A modelling study of once-bred heifer beef production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {389-394}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Sixteen cows were randomly allocated tot he two treatment groups; one was given high digestibility hay (57\% DMD and the other low digestibility hay (52\% DMD). Hay was available to appetite during the daytime, while the cows grazed on a common pasture allowance (12 kg DM per cow) at night. Cows offered high digestibility hay ate more hay (P<0.01) but less pasture (P<0.05) than those on the low digestibility hay. Pasture intake was reduced by 0.2kg DM for each increase of 1 kg DM eaten as high digestibility hay. Cows offered the high digestibility hay ate more hay (P<0.01) but less pasture (P<0.05) than those on the low digestibility hay. Pasture intake was reduced by 0.2 kg DM for each increase of 1 kg DM eaten as high digestibility hay. Cows offered the high digestibility hay produced slightly more milk than those on the low digestibility hay. This difference average 1.3 L per cow daily, but was significant only in week 1. The composition of milk did not differ between the two groups. The cows offered the high digestibility hay also gained significantly more liveweight. The data show that the quality of supplementary hay has an effect on milk production, but that the effect is smaller than might have been predicted because of the increased substitution of hay eaten instead of pasture by cows given the higher quality hay and because of increased liveweight gain by these cows. The probable economic value of high digestibility supplement is discussed briefly. }, issn = {1176-5283}, author = {Keeling PCB and Morris ST and Gray DI and Parker WJ} } @conference {40335, title = {Non-milk constituents in replacers for calf rearing}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {323-326}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {This study was carried out to investigate central nervous system pathways which may be involved in the depression of food intake exhibited by parasitised lambs. Ten lambs with intake depression (c.20\%; p<0.05); as a result of chronic infection with 4000 T.colubriformis larvae/day together with 10 non-infected animals were used in a factorially designed experiment. The factors were a 24 h fast or no fasting followed by; saline solution (control), or 0.6 mg/kg brotizolam (blocks satiety signals at the ventromedial hypothalamus), or 0.125 mg/kg of naloxone (an opioid antagonist), all in a 2 ml volume given i.v. immediately prior to feeding. Trickle infection depressed mean daily intake by 20\% (p<0.05), likewise short term intake was depressed by infection (p<0.05). Fasting stimulated both short term and daily intake by approximately 100\% (p<0.001) and 12\% (p<0.05) respectively. Naloxone depressed cumulative intake for up to 2 h (p<0.01 - p<0.001) while brotizolam stimulated intake at both 60 and 120 minutes (p<0.001). These results show that opioid signals stimulate food intake in lambs and that fasting will overcome the effects of parasitism on appetite in the short term. A lack of opioid signals may be a factor in parasite induced food intake depression. }, issn = {1176-5283}, author = {Wilson GF and Brookes IM and Lynch GA and Billington AC} } @conference {40341, title = {Nutritional effects on fibre growth cycles and medullated fibre production in Angora goats}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {359-364}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Carcass composition data from 1430 carcasses were used to obtain prediction equations for lean weight and fat weight as a function of hot carcass weight (HCW) and GR measurements taken at slaughter. The equation to predict lean weight was: 0.316+(0.547 x HCW) - (0.070 x GR), R}, issn = {1176-5283}, author = {Nixon AJ and Saywell DP and Bown MD} } @conference {40282, title = {Oestrous behaviour and luteal function in anoestrous red deer hinds treated with a GnRH analogue or oestradiol}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {55-62}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Five-year old Coopworth pregnant twin bearing ewes were allocated to four periods of treatment which commenced either -4, 0, 6 or 12 weeks from lambing periods 1 to 4, respectively. Within each period, pregnant ewes were further allocated to one of two groups (n+6) one receiving 4000 Ostertagia(Teladorsagia) circumcincta larvae per day for 30 days (MCI) or no infection (NIC). All ewes were housed indoors and offered a pelleted diet. Faecal egg counts, ewe liveweight, food intake, milk production and serum pepsinogen were determined weekly. Wool growth, fibre diameter and tensile strength were determined on wool grown within each experimental period. Abomasal damage, as judged by serum pepsinogen, occurred during all periods of infection. The magnitude of production losses varied with time of challenge. Parasitism reduced milk production by 10-59\% (p<0.01) and wool staple strength by 29-44\% (p<0.01) with greatest effects on wool staple strength being recorded during period 1. During lactation food intake (p<0.01) was reduced by 30\% in period 1 by parasitic infection but little effect was seen prior to parturition. These data confirm that significant production losses do occur in breeding ewes. The effects on ewe production of any larval challenge will depend on the timing of the challenge will depend on the timing of the challenge and on the susceptibility of the ewe to infection at that time. }, issn = {1176-5283}, author = {Duckworth JA and Barrell GK} } @conference {40359, title = {Optimization of {\textquoteright}herd-in-calf rate{\textquoteright} with respect to the length of the postpartum anoestrous period in Angus cows suckling calves}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {459-464}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A trial was undertaken to evaluate the effectiveness of the CIDR-B in buffalo. Twenty four, 20 month old buffalo heifers had CIDR{\textquoteright}s inserted (day 0) for 12 days. Each heifer was injected intramuscularly with 10 mg of oestradiol benzoate at CIDR insertion and 150 IU of PMSG at CIDR removal. Two buffalo bulls fitted with chin ball harnesses were introduced into each of 2 groups of 12 heifers. Continuous observations of mating activity commenced 24 hours after CIDR withdrawal. The heifers were bled for progesterone analysis on days -20, -9, 0, 2, 7, 12 and 26.9 CIDR{\textquoteright}s (38\%) lost from the heifers were replaced immediately after the losses were noticed. The mean interval from CIDR removal to onset of mating activity was 50.3}, issn = {1176-5283}, author = {Pleasants AB and Barton RA and Morris ST and Anderson WJ} } @conference {40297, title = {Out-of-season embryo transfer in five breeds of imported sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {129-132}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Three groups of 2th Romney wethers were given 0, 12g ZnO fortnight-1 and 12gZnO week-1 respectively for 18 months. Plasma trace element levels were monitored regularly over this period. At the end of the trial the animals were slaughtered and various organis, muscle, skin and wool were removed and analysed for a wide range of elements and for metallothionein. Zinc treatment resulted in significantly elevated Zn in plasma, red blood cells, liver, kidney, intestine and pancreas. Copper concentrations in liver (272 }, issn = {1176-5283}, author = {Greaney KB and McDonald MF and Vivanco HW and Tervit HR} } @conference {40296, title = {Oxygen consumption and the energy costs of Na+, K+ -transport in the rumen of Holstein-Friesian steers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {123-128}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The nutritive value of perennial ryegrass (RG), low mass Matua prairie grass (LM) and high mass Matua prairie grass (HM) swards were measured during early spring, late spring, summer and autumn of 1987/88 and 1988/89. Pre-grazing herbage masses were approximately 3000, 4000 and 5500 kgDM/ha for RG, LM and HM swards, respectively. Lactating cows on a common herbage allowance (50 kg DM/cow daily), grazed the ryegrass and Matua swards at mean intervals of 25 and 35 d, respectively. Values for the concentration of N (\% OM) and DMD in whole plants, average across all seasons, were (\%N) 2.6, 2.5 and 2,3, and (\% DMD) 71.4, 71.1 and 69.4, respectively, for RG, LM and HM. The values for HM were significantly lower than those for the other two treatments. Values for the concentration of N and DMD in green grass leaf were (\%N) 3.4, 3.5 and 3.5, and (\% DMD) 72.4, 71.9 and 71.5, respectively, for RG, LM and HM. There were no significant differences in \% N between the three treatments; the differences in \% DMD between RG and HM was significant. During the autumn in both years, the LM treatment had a higher value for DMD \% than the RG treatment (by 3 to 6\% units). These results indicate that even at high pre-grazing herbage masses (4-5 tDM/ha) Matua prairie grass plants maintained relatively high nutritive values in green leaf and stem. }, issn = {1176-5283}, author = {Kelly JM and McBridge BW and Milligan LP and Waldo DR} } @conference {40316, title = {Plasma hormone concentrations in pasture-fed Friesian cows treated with recombinantly-derived bovine somatotropin (bST)}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {235-238}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Dairy farmers often debate the importance of liveweight of rising 2 year old heifers and the value of various heifer wintering systems on subsequent production. Lifetime performance of all dairy cows born on the Taranaki Agricultural Research Station have been recorded since 1978 on a computerised data base. This data base was utilised to determine the liveweight gain of heifers and cows over winter and the effects of this on production in the following season. Initial analysis of the data showed a significant (P<0.01) age effect on winter liveweight gain within a mixed age herd of cows. The average liveweight gain over eight years of the older cows (4 yr +) was 3 times that of the rising 2 year olds. Further analysis showed a significant (P<0.05) age effect on the relationship between liveweight at calving and production of milkfat in the following season. Higher liveweight at calving resulted in a greater increase in production for 2 year olds than for older cattle. The conclusion to be drawn from this is that wintering rising 2 yea old heifers separately from older cows to achieve higher liveweight may have beneficial effects on the following seasons production. A field trial in winter 1990 to test this assumption showed the winter liveweight gain of rising 2 year old heifers and mature cows, offered the same herbage allowance, was significantly (P<0.01) higher when wintered separately than wintered as a mixed age herd. Subsequent milk solids production from the two-wintering systems was the same despite different liveweight at calving. Aspects of herd behaviour were suggested as the cause of the nil response. }, issn = {1176-5283}, author = {McCutcheon SN and Hoogendoorn CJ and Lynch GA and Wickham BW and Breier BH and Gluckman PD} } @conference {40337, title = {Relative economic values of wool processing parameters}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {333-338}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Seasonal wool growth pattern and fleece characteristics of Doreset x Romney ewes lambing in either autumn or spring and rearing 0, 1 or 2 lambs were measured over 2 years. The ewes were shorn twice- yearly in March and October. Season of lambing influenced the seasonal pattern of wool growth. Autumn lambing ewes did not show as marked a seasonal decline in wool growth during the winter. March shorn fleeces were coarser (2.5 um), stronger (20 N/ktex), and yellower (1.1 Y-Z units) than October shorn fleeces of October shorn spring lambing ewes. On the basis of price trends over the last 5 years, net wool returns from autumn lambing ewes would exceed those from spring lambing ewes by approximately 80c/ewe/year. }, issn = {1176-5283}, author = {Maddever DC and Carnaby GA and Ross DA} } @conference {40352, title = {Responses to divergent selection for plasma insulin-like growth factor-1 (IGF-1) in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {417-422}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied }, issn = {1176-5283}, author = {Morel PCH and Blair HT and McCutcheon SN and Breier BH and Gluckman PD} } @conference {40313, title = {Ribozyme mediated modification of alpha-lactalbumin gene expression}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {219-224}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The effectiveness of hand combing, machine combing and body stocking covers relative to shearing were compared as methods of harvesting cashmere. Cashmere does were shorn on 4 August and combed on 4 August, 29 August and 3 October. Goats were covered and shorn on one side on 4 August and on the other on 3 October. Only 9 of the 40 goats retained their covers until 3 October. Machine combing was the least effective method of harvesting cashmere and produced a half fleece of 18}, issn = {1176-5283}, author = {L{\textquoteright}Huillier PJ and Bellamy AR and Davis SR} } @conference {40292, title = {Rumen digest and other body measurements in relation to bloat susceptibility in cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {103-106}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Following the introduction of bucks on day 0 to isolated does there are peaks of oestrus on day 3 and day 7. While the day 3 peak is associated with low conception rates the day 7 peak is useful for partial synchrony for artificial insemination (AI). In this trial near Te Kuiti oestrous does were drafted off twice daily, starting day 5, following buck introduction. Those drafted in the evening were artificially inseminated laparoscopically with frozen- thawed semen the next morning and those drafted in the morning were artificially inseminated in the afternoon. On two farms the proportion of 207 and 123 mature does artificially inseminated on day 7-8 (day0=April 11) were 55\% and 74\% respectively, on day 6-10 inclusive 87\% and 94\% were artificially inseminated. On farm 1 on day 7-8 and day 6- 10 only 25\% and 28\% of 205 two tooths were artificially inseminated, in contrast on farm 2 74\% and 84\% of 70 two tooths were artificially inseminated. The farm 1 two tooths were 3.6 kg lighter than those on farm 2. CIDR-PMSG synchronised does from farm 1 (48 mature and 33 two tooth) were AIed on-time on days 6 and 10. There was no significant difference between the pregnancy rates of the CIDR synchronised (60\%) and the buck induced does (56\%). There were additive effects of type of oestrus induction and live weight on the \% multiple pregnant. At 20 kg live weight the predictions of the \% multiple pregnant were buck effect 11\%, CIDR-PMSG 26\%, and at 30 kg live weight 51\% and 75\% respectively. }, issn = {1176-5283}, author = {Morris CA and Carruthers VR} } @conference {40357, title = {Screening herds for cows with a history of twin calving}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {447-452}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A monoclonal antibody to oestron sulphate (ES) was generated, and used in the development of a radioimmunoassay to measure ES concentrations in whole milk of cows. The mean }, issn = {1176-5283}, author = {Morris CA} } @conference {40318, title = {Secretion of insulin-like growth factor I and II from blood into milk of lactating goats}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {245-248}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied }, issn = {1176-5283}, author = {Prosser CG and Fleet IR and Davis AJ and Heap RB} } @conference {40325, title = {The selection and breeding of Merino sheep for footrot resistance}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {283-286}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {An efficient farm AI system for sheep requires ready identification of, and access to, oestrus ewes. It is well known that ewes in oestrus seek out and remain near rams. The present experiment evaluated a variety of systems for trapping oestrus ewes attracted to two decoy rams. These systems included traps with one or two entrances, and traps sited 1.5 or 6 m from the rams. In each trial, 13 to 16 ewes in a flock of 45 mixed age and mixed breed sheep were artificially induced into oestrus and the proportions of oestrus ewes entering the trap was recorded. In addition, the trapping rate in a flock of naturally cycling 1}, issn = {1176-5283}, author = {Paterson R and Paterson H} } @conference {40349, title = {Selection for lean and against fat in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {401-404}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A model quantifying outputs of carcass from pasture inputs was used to study factors affecting biological efficiency (BE) of finishing beef from 6 months to slaughter. Two factors which determined biological efficiency (BE, kg carcass gain/ha/yr) on pasture were pasture utilisation and animal conversion efficiency. Effects of stocking rate, length of finishing period (1 v 2 years), mature size and maintenance efficiency of beasts on BE and its components were studied. Stocking rate was the major factor affecting utilisation rate however more lighter (eg. 12\% more 750 kg than 900 kg mature sized) cattle need to be run to achieve equivalent pasture utilisation. Nine percent less cattle can be run in a 2 year system. Average conversion efficiency was 40\% lower from finishing at 2 years than 1 year. An increase in mature size from 750 to 900 kg increased animal conversion by 14\%. A 20\% decrease in maintenance requirements increased animal conversion by 10\%. Constraints to produce specified carcass weights further favoured BE with high mature weight beasts, particularly at intermediate carcass weights (250 kg). Breeding cattle for high mature size appears the best way of improving the cattle available for finishing. }, issn = {1176-5283}, author = {Clarke JN and Rae AL} } @conference {40327, title = {Selection for resistance to parasites in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {291-294}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A milk replacer containing 40\% non-milk constituents (V) was compared with a proprietary milk replacer (M) in two calf-rearing systems (H and R) using calves at pasture. Forty-eight, four week old Friesian calves were allocated to one of four treatments (in two replicates) and offered reconstituted milk replacers (140 g/l) : MH and VH, 81 daily for 3 weeks plus ad lib meal for two weeks; MR and VR, 41 daily for 5 weeks. Replacer M gave significantly (P<0.01) greater liveweight gains over the first 3 weeks for calves in treatment H but not in R. Treatment H calves showed a temporary growth check following weaning and again following the termination of meal feeding. Treatment R calves showed a progressive increase in daily rates of gain during the experiment. By 5-6 months of age the mean body weights of calves in all four groups were similar indicating that there were no adverse carry-over effects of replacer V, or the system of feeding. Significant savings in the cost of calf rearing are therefore possible. }, issn = {1176-5283}, author = {Parker AGH} } @conference {40280, title = {The sexual behaviour of alpacas imported to New Zealand from Chile}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {43-46}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {FSH concentrations were examined in 6 FecB FecB (BB) ewe, 3 BB ram and 5 Fec+Fec+ (++) ram full-sibling pairs of Booroola Merino x Romney lambs between 2 and 20 weeks of age. The purpose of this study was to compare variation in FSH profiles within and between prepubertal full-sibling pairs of Booroola ewe and ram lambs, to evaluate their usefulness as control-treatment pairs in endocrinological studies. In ewe lambs, FSH concentrations increased with liveweight and age to reach distinct peaks at 7-12 kg liveweight and at 3-9 weeks of age. Variation between pairs was significantly greater than within pairs for liveweight at all ages, FSH concentrations up to 9 weeks of age, and maximum FSH concentration, but not for age or liveweight at peak FSH. In ram lambs, FSH concentrations were lower than in ewes but followed a similar pattern, with FSH peaks at 12-17 kg liveweight and 5-10 weeks of age. The geometric mean maximum FSH concentrations were 1.44 and 0.81 (LSR 1.78) ng/ml for BB and ++ groups respectively (P<0.05). Between- pair variation was significantly greater than within-pair variation for birth weight, liveweight to 7 weeks of age, peak FSH, and age at peak FSH. Mean FSH concentration and liveweight showed no relationship within or between ram pairs, or between ewe pairs, but the heavier sibling within all six ewe pairs had the higher FSH concentration (P<0.05) most samples up to 7 weeks of age, but not thereafter. The reduced variation in gonadotrophin concentrations within compared with between full-sibling pairs suggests they have considerable value as control-treatment animals in endocrine studies on prepubertal developments. }, issn = {1176-5283}, author = {Pollard JC and Moore GH and Littlejohn RP} } @conference {40287, title = {Sheep map: The New Zealand programme to map the sheep genome}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {85-86}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A series of four trials, each involving 1200 ewes have been conducted over the period 1986 to 1990. Ewes have been treated with various synchronisation treatments and the time to onset of oestrus monitored each month of the year. Results indicate that while overall mean values for each year don{\textquoteright}t differ, there were significant seasonal effects within years with the interval to onset being shorter during the breeding season. However, the maximum difference between monthly means in any one year varied from 27 h to 17 h. Significant effects of synchronisation device were seen with ewes treated with sponges having a longer (+ 8 h) interval to onset than ewes treated with CIDR devices. While effects of ewe age and ewe liveweight were seen in some trials no consistent trend was identified. On most occasions significant interactions with month of year indicated inconsistency of effect within any one trial. The recorded variation in interval from device removal to onset of oestrus is in agreement with that reported between flock in the field. This variation is sufficient to effect conception rates to artificial insemination performed on a time basis and evaluation of contributing factors is required for the development of protocols for this activity. }, issn = {1176-5283}, author = {Hill DF and Broad TE} } @conference {40360, title = {Short term intake of Friesian heifers grazing three pasture species}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {465-468}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Objective measures of muscularity were calculated for 1602 Romney and Romney-cross carcasses which were the progeny of 102 sires. Muscularity was defined as a measure of muscle thickness relative to carcass length. Phenotypic and genetic parameters were calculated from REML estimates of variance and covariance components. Different measures of muscularity had genetic correlations with one another between .48 and .84 and phenotypic correlations between .30 and .62. Measures of muscularity and high heritability (.40 to .68), positive genetic correlations with weight of carcass lean (.32 to .53) and carcass weight (.08 to .32) and negative genetic correlations with carcass fat (-.06 to -.33), and carcass length (-.11 to -.30). Single trait selection on muscularity was expected to result in increased lean and decreased fat. Selection on some of the muscularity measures was expected to result in increased subcutaneous fat. When the breeding objective gave positive emphasis to lean weight and negative emphasis to fat weight and the selection criteria were carcass weight and a muscularity measure, the muscularity measure that gave the greatest economic response to selection was that which used the longissimum muscle width (A) as a measure of muscle thickness. }, issn = {1176-5283}, author = {Elliott AW and Hughes TP} } @conference {40293, title = {A simplified MOET technique for Merino ewes carrying a double copy of the Booroola FecB gene}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {107-110}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Two trials were conducted to determine the effect of different oestrous synchronisation regimens on oestrous behaviour, timing of ovulation and fertility of fallow deer. In Trial 1, 59 mature does were allocated to 6 treatment groups (n+9-10 per group). Does in Groups 1, 2 and 3 each received an i.m. injection of an analogue of prostaglandin F2alpha (PG; 500 ug cloprostenol) on Day 13 of a synchronised oestrous cycle. Animals in Group 2 and 3 also received 50 or 100 IU PMSG respectively at the time of PG administration. Does assigned to Groups 4, 5 and 6 each received an intravaginal CIDR device for 14 days with animals in Group 5 and 6 also receiving 50 or 100 IU PMSG respectively, at the time of CIDR device withdrawal. Incidence of oestrus was higher following treatment with CIDR devices than with PG (29/30 vs 12/29, P<0.001). PMSG induced earlier onset of oestrus (34.6}, issn = {1176-5283}, author = {Shackell GH and Isaacs KL} } @conference {40298, title = {Superovulation in ewes: are follicle numbers a useful predictor of ovulation rate?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {133-138}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The grazing behaviour of mixed age cashmere producing does was recorded on pasture dominated hill country at six physiological stages; post-weaning, pre-mating, early pregnancy, late pregnancy, early lactation and mid lactation. Observations were conducted from sunrise to sunset on three consecutive days at each physiological stage. Activity, land slope, time and position of focal animals were recorded. Flock position over the study site was also registered. At each physiological stage grazing was the predominant activity (34-63\% of the time observed). The major grazing period occurred during the afternoon. Grazing occurred predominantly on steep and easy slopes (>70\% of the time observed). Pasture height influenced the goats preference for the slope grazed. The does travelled in a regular pattern around the study site. This pattern was less distinct when the does had kids at foot. Activities observed during late pregnancy differed considerably from activities observed at other physiological stages. Some of these differences included more time spent standing and no distinct afternoon grazing period. Rain was the main event to interrupt grazing and initiate a change in the movement pattern of the does. }, issn = {1176-5283}, author = {McMillan WH and Hall DRH} } @conference {40317, title = {The time-course of milk yield and hormonal responses following growth hormone injections in hourly-milked goats}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {239-244}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied }, issn = {1176-5283}, author = {Davis SR and Hodgkinson SC and Farr VC} } @conference {40285, title = {The timing of oestrus, LH surge and ovulation in ewes following synchronisation with MAP sponges FGA sponges or CIDR{\textquoteright}s}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {73-78}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {As part of a programme to increase the number of homozygous (FecB FecB) replacements available in the Booroola Merino flock at the Tara Hills Research Station a MOET technique was utilised. Because ewes of BB genotype are difficult to superovulate, with predictable results, using conventional treatment regimes, a simplified programme aimed at enhancing the natural ovulation rate was used. Thirty eight ewes were treated for 10-11 days with intravaginal sponges. The ewes were then injected with 500 iu of PMSG on day 15 after sponge withdrawal and joined with entire rams for 5 days. Sixty six percent of ewes were marked by the ram and the mean ovulation rate of these was 8.3 (range 5- 18). Embryo recovery rate was 93.4\% following retrograde flushing of the fallopian tubes. Fertilisation rate was 68\% and 5.3 embryos were transferred per donor operated (range 0.-11). The ewes were remated and lambed naturally. By using a combination of MOET and remating, 24 donor ewes produced a mean of 3.3 lambs weaned compared to 1.4 lambs weaned by their naturally mated flock mates. }, issn = {1176-5283}, author = {Shackell GH} } @conference {40286, title = {The use of dinucleotide repeats or microsatellites as genetic markers in domestic animals}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {79-84}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Progesterone releasing devices are used to induce and synchronise oestrus in ewes and to provide supplementary progesterone post-mating to increase embryo survival. Because of its physical characteristics the Type-G CIDR device can be washed and re-used. Two trials each involving 1200 ewes were conducted. CIDR devices previously used for 14 days were evaluated in comparison to unused devices for their efficacy in; (1) induction and synchronisation of oestrus (50 ewes were treated with either new or used devices each month of the year with 400 I.U. PMSG given at device removal and the onset of oestrus and pregnancy monitored) or (ii) treatment post-mating (new, used or no devices were reinstated into groups of 33 ewes on Day 6 after a synchronised mating each month of the year. Pregnancy and lambing rates were monitored). Fewer ewes exhibited oestrus after treatment with the used CIDR devices and fewer became pregnant in Trial 1. There was no effect of post-mating treatment on pregnancy rate in Trial 2 but such treatment reduced the proportion of ewes have multiple births. Monthly variations in response were seen in both trials. }, issn = {1176-5283}, author = {Crawford AM and Buchanan FC and Swarbrick PA} } @conference {40354, title = {The use of fine and coarse bucks and G4 does for breeding for cashgora production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {429-436}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Stocking rates for maximum production and economic performance of Holstein-Friesians and Jerseys were predicted by calculating response curves from the regression equations of stocking rate on cow performance. Holstein-Friesians produced higher yields, gross milk incomes and net incomes per cow while Jerseys produced higher milkfat and protein yields, gross milk incomes and net incomes per ha when both breeds were stocked at the same liveweight or for maximum production or optimum economic performance. Maximum net income based on 1990/91 costs and prices occurred at 3.0 and 3.7 cows/ha for Holstein-Friesians and Jerseys respectively. At these stocking rates net income for Jerseys was 5\% higher than for Holstein-Friesians. }, issn = {1176-5283}, author = {Paterson DJ and Litherland AJ and Newman S-AN and Edmonds DK} } @conference {40288, title = {The use of full-sibling pairs to measure plasma FSH concentrations in Booroola ewe and ram lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {87-90}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Forty-eight yearling Holstein-Friesian steers were assigned to three diets (Panicum virgatum (P) var. Cave-in-rock, Dactylis glomerata (D) var. Hallmark and Medicago sativa (M) var. Waterman Loomis 316) fed at two levels of intake (low (L) 65g DM kg-1 liveweight -0.75 day -1 or high (H) 90 g DM kg -1 liveweight -0.75 day -1) during a 6 month growth study. At the conclusion of the study animals were stunned, exsanguinated and promptly eviscerated and the rumen quickly emptied of its contents and subsequently weighed. Upon slaughter, rumen tissue samples were acquired from the ventral sac and placed in oxygenated M199 media. Mucosa and muscularis weights were determined along with their total 02 consumption, ouabain-senitive- (OSO2) and ouabain-insensitive-(OIO2) respiration. Tissue oxygen consumption was determined in vitro using a YSI Clark style electrode. Total, Mucosa and muscularis weights were greater (16.9-43.5\%) with H and tended to be affected by diet (P<0.10). On a tissue basis, rumen muscle O2 consumption was not affected by treatment but mucosal OSO2 and percent inhibition of O2 consumption by ouabain were higher (6.9-94\%) with Medicago. Total rumen O2, OSO2 and OIO2 consumption were higher (8.6-80.5\%) in H (P<0.05) and diet affected OSO2. Rumen muscle total O2 consumption was greatest (3.51 ul 02/mg/hr) for D and altered by level of intake (P<0.03). Mucosal OSO2 and OIO2 were greater with H (P<0.04 and P<0.07, respectively). Total rumen O2 consumption is dominated by organ size rather than changes in weight specific O2 consumption. Therefore, at high forage intakes part of the decrease in the efficiency of ME utilisation is a consequence of increased heat production from the larger rumen. }, issn = {1176-5283}, author = {Isaacs KL and McNatty KP and Littlejohn RP} } @conference {40284, title = {The use of unfrozen semen for in vitro fertilisation of in vitro matured bovine oocytes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {67-72}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Two herds with high (HS) or low (LS) susceptibility to pasture bloat have been selected divergently at Ruakura since 1972 using field bloat scores. The present paper continues studies on weights of rumen digesta, in 92 HS and 81 LS cull cattle experimentally slaughtered from 1985 to 1990. Traits recorded included pre-slaughter weight (PSW), hot carcass weight (HCW), the fresh weight, dry matter percentage (DM\%) and dry weight of rumen digesta, weight of full abomasum and omasum, carcass composition, and weights of heart, liver, kidney and omental fat. In addition, pre-feeding and post-feeding girths at the last rib were obtained on 61 2- to 8-year old cows in mid-lactation, as a possible predictor of variation in rumen contents and in bloat susceptibility. The LS herd had a 10\% greater PSW than the HS herd (P<0.001), and adjustments for body size were therefore made below to all traits from the abattoir except HCW and DM\%. The fresh weights of digesta were similar in the two herds, but the DM\% of digesta was 17\% greater in LS than HS cattle (P<0.001). The weight of abomasum and omasum was 15\% greater in LS than HS cattle (P<0.001), but there was no significant herd effect on fasting weight loss. Heart and kidney weights were 8 to 9\% greater in LS than HS cattle. Ratios of rib girth to chest girth, in the absence of bloat, were not significantly different between herds at 1.172}, issn = {1176-5283}, author = {Seaton AD and Catt JW and Rhodes SL and McDonald MF and Welch RAS} } @conference {40276, title = {A view of recent development on the effect of nutrition on ovulation rate (the flushing effect) with particular reference to research at Ruakura}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {15-24}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The use of unfrozen, diluted bovine semen for in vitro fertilisation (IVF) was investigated. In vitro matured bovine oocytes were incubated with various (0.125 - 4.0 x 10 6/ml) concentrations of washed sperm. Penetration rates ranged from 21\% at low sperm concentrations to 80-100\% above 1 x 10 6 sperm/ml (P<0.01). Unfrozen sperm gave better penetration rates than frozen-thawed sperm. Oocytes were incubated with washed sperm (1 x 10 6/ml) in increasing dilutions of caprogen extender. Sperm penetration was significantly inhibited at dilutions of 10-fold or less (P<0.01). Oocytes were inseminated with washed sperm (1 x 10 6/ml) at various concentrations (0.50 ug/ml) of heparin. No significant differences were found. }, issn = {1176-5283}, author = {Smith JF} } @conference {40279, title = {The welfare of sheep during sea transport}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {41-42}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Sheep and their products contribute significantly to the New Zealand economy. A map of the sheep genome would accelerate the future genetic improvement of sheep by enabling loci for agriculturally and economically important traits to be identified and manipulated. Such a map would also contribute to the development of gene maps of cattle, goats and deer. The core of the New Zealand programme comprises two research groups (DSIR and MAF Technology) located at Palmerston North and Dunedin respectively. }, issn = {1176-5283}, author = {Black H and Matthews LR and Bremner KJ} } @conference {40334, title = {Within-flock ranking of loose wool bulk and fibre diameter to predict wool lustre}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {319-322}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Wiltshire Horn sheep exhibit an annual moult in spring and potentially provide a model for studies on the seasonality of wool growth. Twelve, 1 year old New Zealand Wiltshire ewes (Wiltshire Horn with some Poll Doreset in ancestry) were kept indoors under natural light and fed concentrates and hay. The sheep were cored for extent of fleece shedding every 2 weeks and skin sampled monthly for histological determination of primary and secondary follicle activity. Follicle activity reached a peak in summer and autumn (January to April) with low activity over winter (May to August) resulting in partial or entire shedding of the fleece in spring and early summer (September to December). There was evidence of a subsidiary shedding cycle in the primary follicles in early summer. Seasonal follicle activity was higher and longer in duration than previously recorded in British Wiltshire Horn ewes maintained on pasture. Four sheep with highly seasonal follicle activity cycles were identified as suitable for further studies on the endocrine control of wool growth. Such sheep can be selected from skin samples collected in June, July and August when follicle activity is at a seasonal minimum. }, issn = {1176-5283}, author = {Nicol JJ} } @conference {40346, title = {Wool growth in autumn and spring lambing ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {383-388}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Four trials in early to mid lactation investigated the effect of supplementation with sodium bicarbonate on milk production from cows grazing pasture. In Trial 1, 3 groups of 14 cows received 0, 100 g or 200 g NaHCO3/cow/day for 28 days. Trial 2 assessed whether any effects of sodium carbonate were due to sodium by comparing no supplement, 200 g NaHCO3/cow/day and 140 g NaC1 with three groups of 20 cows for 28 days. In both trials treatments were administered by drenching at each milking. Trial 3 assessed the importance of method of administration. Treatments of no supplement, 100 g NaHCO3/cow/day by drenching at the morning milking, or 100 g NaHCO3/cow/day in the drinking water were administered to 3 groups of 20 cows, during three 21 day periods according to a latin square design. Trial 4 compared rates of 0, 50, and 100 g NaHCO3 via drinking water with 3 groups of 18 cows for 21 days. In Trial 1 milk yield and protein yield were significantly reduced (P<0.10) by drenching 200g NaHCO3/day, compared to the control cows (14.,7 vs 15.3 kg milk/cow/day). The lower dose rate did not affect milk yield or composition. In Trials 2 and 4, none of the treatments significantly affected milk solid yields. Milk, protein and lactose yields from cows on the trough treatment were higher than those for control and drenched cows in Trial 3. Plasma magnesium was lower in drenched cows than in control or trough treatment cows. }, issn = {1176-5283}, author = {Reid TC and Sumner RMW} } @conference {40348, title = {Wool sulphur concentration in fleeceweight-selected and control Romney hoggets}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {51}, year = {1991}, month = {Jan}, pages = {395-400}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Dairy and beef cows (n=349) which had calved at least two sets of twins were identified in farmers{\textquoteright} herds in 1982-85. Their calving performance is summarised here, and an experimental herd was founded from a sample of them. The calvings of 11 high twinning-rate dairy herds identified from this publicity are also summarised. Repeat-twinning cows were from factory-supply dairy herds (66\%), town-supply dairy herds (10\%), beef herds (21\%) and house cows (2\%). The twin calving rate in factory-supply survey herds with Friesians was 2.6\%, greater than the national average. There were, on average, 2.44 twin or triplet sets per cow. Of all the multiple births, 1.3\% were triplet sets. Data on sex ratios of calves from the twinning cows suggested that probably all their twins were the result of multiple ovulations. Perinatal calf survival rates averaged 86\%, with 80\% of sets having both calves surviving; 21\% of twin calvings were associated with a retained placenta, and 18\% of twin calvings were assisted. Mean ages of cows at first and later twin calvings were also summarised. The 11 {\textquoteright}elite{\textquoteright} herds averaged a 4.1\% twin calving rate (21 000 records), with 16\% of cows calving at least one set of twins. Subsequent twin calving frequencies were summarised. The 69 foundation experimental cows averaged 2.39 twin sets and a 50\% twin calving rate/year at purchase, and subsequently (1983-89) a twin calving rate of 10.3\% (18 sets/174 calvings) compared with controls at 0.8\% (1/121). }, issn = {1176-5283}, author = {Sun YX and Koolaard JP and Blair HT and Lee J and McCutcheon SN} } @conference {40249, title = {Absorption of DNA to the sperm of rams, bulls and fallow bucks}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {407-410}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The algorithm for a Fortran program which simulates growth of a lamb is presented. The basis of the algorithm is the theory of growth and feed intake by Emmans. The advantages of the current algorithm are its simplicity, the few generalised equations and its easy use at any stage of the growth curve. }, issn = {1176-5283}, author = {Peterson AJ and Schofield KM and McLaughlin RR} } @conference {40246, title = {Animal industries in the 21st century - conclusions and challenges}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {393-396}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Bisected embryos not only create identical twins, but can also improve the efficiency of embryo transfer. We report here our experiences in applying the technique to sheep MOET programmes. Our basic technique involves holding a Day 5-6 embryo by negative pressure on a holding pipette and tearing the zona pellucida using 2 needles. A razor blade fragment is used to bisect the embryo and if required, a suction pipette manipulates demi-embryos into suitably prepared host zonae. In a preliminary study bisected embryos were examined for development during 24-48 h culture. Bisection in Ca2+, Mg2+-free media had no effect on viability. Naked demi-embryos blastulated more readily than those which were zona-enclosed and later stages tended to be the most viable, with morulae showing particularly poor development. This was supported by transfer data, where 11\% of bisected late morulae, 50\% of early blastocysts and 74\% of blastocysts resulted in lambs. In comparison, 40\% of control (unbisected) embryos lambed. Transfer of zona-enclosed demi-embryos tended to yield more lambs per original embryo (67\%) than naked demi-embryos (43\%). When the technique was applied to early blastocysts and blastocysts during 3 exotic sheep multiplication programmes in 1988, 47\% and 55\%, 100\% and 39\%, 73\% and 47\% of bisected and control embryos resulted in lambs respectively. Survival to lambing of dehydrated late morulae, bisected and subsequently enclosed in zonae, was similar to untreated control embryos (73\% VS 59\%) and greater than for naked embryos (36\%). Our experiences indicate that bisected early blastocysts and blastocysts can increase the number of offspring in a MOET programme. However, since few blastocysts are available for bisection, and survival of demi- embryos is variable, we do not routinely use the technique. }, issn = {1176-5283}, author = {Wallace RD} } @conference {40245, title = {Animal industries into the 21st century: a wool perspective}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {387-392}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The MAFTech Sire Referencing Scheme is a national programme to evaluate rams, via progeny testing, throughout New Zealand. Phenotypic effects are reduced by using "Link sires" to make comparisons between properties valid. To enable link sires to be used over large numbers of animals in diverse locations, extensive use is made of Artificial Insemination (AI). Data from over 3,000 ewes mated by AI during the 1989 breeding season are presented. Various factors and their interactions were examined by fitting a generalised linear model with binomial distribution. The model showed that: the non-return rate from cervical insemination with chilled semen was 61\% for ewes which had been treated with CIDRs and 62\% (SED 3.4) for naturally cycling ewes; for frozen/thawed semen inseminate by the intrauterine route the corresponding rates were 70\% and 40\% (SED 7.0). In ewes treated with CIDRs the non-return rate was lower for cervical compared to intrauterine in semination (61\% vs 70\% SED 4.0). Ewes which were in oestrus more than 24 hours before insemination had a non-return rate of 58\% compared to 63\% (SED 2.6) for ewes which were in oestrus between 24 and 17 hours before AI and 71\% (SED 3.1) when oestrus occurred less than 17 hours before AI. There was no evidence of an interaction between inseminated increased. (Coefficient for logit regression 0.14 se 0.064). Technicians success rate ranged from 51\% to 76\% non returns, when adjusted for other factors. Although differences among the 31 sires did not contribute significantly to this model, predicted non-return rates when sire was added to the model ranged from 39\% to 86\%. There was no evidence that ewe breed influenced non-return rate. }, issn = {1176-5283}, author = {Wiggins LK} } @conference {40244, title = {Animal industries of the 21st century : a meat industry viewpoint}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {381-386}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The use of modern technology is having a major effect on the structure of ram-breeding in NZ. The uptake of sire referencing schemes (SRS) and artificial insemination (AI) is having an impact on the whole structure of breeding groups and the industry. The role of traditional group breeding schemes is being questioned by the industry. The structure of New Zealand dairy breeding underwent a period of change with the introduction of AI and sire proving in the 1950{\textquoteright}s. Some aspects of these changes are relevant to the sheep industry. The decrease in the size of the national flock, increasing ram ratios and the use of AI will all impact on the industry over the next 5-10 years. The industry is responding to the new environment with groups like the NZ Romney Development Group and the Perendale Genetic Development Group re-evaluating their objectives and making major changes to their structures. This paper looks at these changes and the likely effect on the sheep breeding industry. }, issn = {1176-5283}, author = {Thompson G} } @conference {40256, title = {Animal production and the {\textquoteright}greenhouse gases{\textquoteright}}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {443-448}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied }, issn = {1176-5283}, author = {Reid CSW} } @conference {40241, title = {Animal production in the future - a New Zealand response}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {361-372}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {As a pre-requisite to examine the possibility of using spermatozoa as a vector for the incorporation of foreign DNA into livestock, the ability of sperm from sheep, fallow deer and cattle to bind exogenous DNA was examined. The DNA was obtained from the plasmid pMK1 linearised with EcORIXhoI and end-labelled with 32P. Fresh sperm from all species bound DNA with maximum binding occurring after 1hr of incubation. Frozen sperm bound less DNA and formaldehyde treated sperm did not bind. Seminal plasma inhibited binding as did heparin and also high divalent cation concentrations. Capacitated ram sperm bound more than uncapacitated (64\% vs 40\%) and uterine fluids from sheep two-days post-estrus did not interfere with DNA binding to the capacitated ram sperm. Increasing the concentration of washed capacitated ram sperm from 1 x 10 6/ml to 30 x 10 6/ml and with a DNA concentration of 0.25 mg/ml decreased the number of molecules of DNA bound from 38,000 to 1,600. There was wide variation among rams in the percentage of DNA bound after 1hr incubation, ranging from 15-80\% (n=7). These results suggest that this procedure may be a possible method for the incorporation of foreign DNA into livestock by intrauterine insemination. }, issn = {1176-5283}, author = {Fennessy PF} } @conference {40242, title = {Animal researchers and farmers must take heed of changing attitudes toward animal welfare and the protection of the environment}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {373-374}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Genetic variation in the beta chain of haemoglobin (HBB) and the beta chain of follicle stimulating hormone (FSHB) was analysed for linkage with the Booroola F gene in large half-sib families or a backcross Romney x Booroola Merino flock where the Booroola F gene was segregating. The half-sib families were highly informative at the HBB locus with 6 of 7 sires heterozygous (AB) for the two alleles. Recombination between the HBB and F gene loci were observed in all six families and the F gene was significantly excluded from within 15 centimorgans (cM) of HBB. A cDNA probe for the FSHB gene detected an insertion/deletion polymorphism close to exon 3 of the gene. Recombination was observed in 4 pedigrees in the half-sib families and the backcross flock and the F gene was excluded from within 5 cM of the FSHB gene. }, issn = {1176-5283}, author = {Sutton J} } @conference {40268, title = {Biochemical mechanisms related to overfatness in lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {479-482}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A mechanistic model was used to measure the impact of changes in climate (temperature, rainfall and solar radiation) and a 75\% increase in the concentration of atmospheric carbon dioxide on pasture and animal production on eight representative New Zealand lowland farming systems. The climate changes increased annual pasture dry matter production per hectare by 10-30\%, assuming no changes in pasture composition. A 75\% increase in CO2 concentration increased pasture production by around 40\%. Together, climate change and increased CO2 concentration increased yields by 50-77\%. In all cases, the seasonal distribution of pasture production was not greatly affected. Both climate change and increased CO2 concentration individually increased annual milk production per hectare by around 24\%, lamb meat and beef by around 30\% and wool by around 22\%, under the constant farm management systems selected. The increases in production were mainly due to increases in stocking rate resulting from the increased pasture production, but increased conservation and feeding out of hay were required. The model predicted an increase in lamb growth rates. Milk, meat and wool production was higher under climate change than under increased CO2 concentration in Southland, but the opposite was true in northern New Zealand. The combined effect of climate change and increased CO2 concentration was greater, with potential increases over the two scenarios averaging 52\% for milk, 57\% for lamb and beef and 46\% for wool. }, issn = {1176-5283}, author = {Payne E} } @conference {40250, title = {The Booroola F gene is excluded from close genetic linkage with either the haemoglobin Beta or follicle stimulating hormone Beta loci}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {411-416}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied }, issn = {1176-5283}, author = {Montgomery GW and Tate ML and Sise JA and Hill DF} } @conference {40230, title = {Carcass and meat quality in possums (Trichosurus vulpecula)}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {293-296}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Production data were collected over 4 years from a flock of 600 mixed-age Romney, Coopworth and Perendale ewes. There were approximately equal numbers of each breed. Ewes within breeds and age groups were randomly allocated to be shorn either once-yearly in January, once-yearly in July or twice-yearly in January and July. All ewes were grazed as a single mob throughout the year, except over mating when they were divided into breed groups and joined with rams of their own breed. The twice-yearly shorn ewes gave birth to, and weaned, heavier lambs and grew more total clean wool than the 2-once-yearly shorn groups which were similar. Shearing treatment did not affect ewe live weight, aspects of lamb production other than birth weight and weaning weight or total greasy wool production. Incidence of casting was less than 1\%. Net wool returns from the ewes shorn once-yearly in July exceeded that of the ewes shorn twice-yearly which exceeded that of the ewes shorn once-yearly in January. }, issn = {1176-5283}, author = {Hogg BW and Catcheside LM and Mercer GJK and Pearson AJ and Ashby MG} } @conference {40271, title = {Carcass composition of autumn- and spring-born lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {489-492}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The sexual behaviour of alpacas joined under a selective breeding programme was recorded to assess performance and to examine ways of providing optimal conditions for mating. Groups of 4 females and 1 male were joined in paddocks for 5 days (3 groups) or in pens for 3.5 hours on 2 consecutive mornings (3 groups). Sexual activity was more variable in paddocks compared with pens, and more females were mated in pens. Duration of copulation was longer in pens that in paddocks, and for first compared with subsequent matings. Within pens, sexual activity was more intense during the first hour following joining than for the subsequent 2.5 hours, on Day 1 than on Day 2, and differed between groups. Females became more receptive later in the mating sessions. The study indicated that pen mating using small single-sire groups, over short periods, was a suitable method of breeding alpacas. }, issn = {1176-5283}, author = {Reid TC and Kirton AH and McQueen IPM} } @conference {40218, title = {The challenge of endoparasitism: developments in the control of nematode infections of sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {215-228}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Twelve Romney wether lambs, average weight 28kg, were randomly divided into two groups, namely an untreated control and an Fe treated group. All animals were grazed together on a ryegrass/white clover pasture for 12 weeks. The Fe intake of the control animals was estimated to be 247 mg/day while that for the treated animals was 827 mg/day with the extra Fe (FeSO4.7H2O) given orally in a gelatin capsule. Increasing the Fe intake had no effect on DM intake or growth rates but significantly (P<0.05) increased the Fe content of the lungs, spleen and digestive tract. No other changes in Fe concentrations were found in the other soft tissues or bone. There was a marked decrease [50\%] in the Cu content of the liver (a major storage organ for Cu) when the Fe treated lambs were compared with the control animals. The fact that a moderate increase in the intake of Fe can markedly reduce the Cu status of lambs may be a more important finding than has been previously realised. }, issn = {1176-5283}, author = {Anderson N} } @conference {40234, title = {Changes in the fur quality of caged brushtail possums (Trichosurus vulpecula) maintained in captivity}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {311-316}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {This paper backgrounds important features which are likely to influence the future of animal production in New Zealand. They include the importance of being in the quality market, consumer attitudes, market access and environmental/welfare concerns. In view of the changing perceptions about animal production, the place of technology in on-farm production needs to be carefully considered. Technologies can be defined as {\textquoteright}soft{\textquoteright} or {\textquoteright}hard{\textquoteright}, the latter being those which introduce major perturbations into the system. The impact on the whole system is particularly important. The possibilities for genetic improvement are considered in detail. The soft technology approach is favoured in that it works with existing genetic variation but uses new technology approach is concerned mainly with the development of transgenic animals. Overall, developments in technology have much to contribute to the animal industries in New Zealand, but the importance of off-farm issues such as marketing, market access and product development are particularly critical. There is a need to take a broad view of animal production in considering the future. }, issn = {1176-5283}, author = {Pearson AJ and Ashby MG and MacGibbon RJ} } @conference {40202, title = {Characterisation of the insulin status of lambs and consequences for carcass composition}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {97-100}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {As part of the study into the mechanism by which nutrition influences ovulation rate two trials have been conducted to examine the effect of protein intake on the negative feedback of oestradiol-17Beta (E17Beta) on plasma FSH levels. In Trial 1 three groups of ovariectomised ewes (n=8) fed on a low protein (LP 11\%, 10 MJ ME) diet were treated with silastic implants of E17Beta. Four days after implant insertion one group was changed to a high protein (HP 22\%) diet while another was treated orally for 10 days with phenobarbital (1 g/d). The E17Beta implants were removed 6 days after treatment started. In Trial 2 groups of ewes (n=6) were given either full (HE) or 1/2 size (LE) implants for 5 days. All ewes were fed on a LP diet but 2 groups were infused abomasally with 100g/d of protein (HP) commencing 3 days before implant. FSH levels were monitored 4 x d throughout both trials and expressed as a percentage of pre-treatment values. In Trial 1 FSH levels were 33\% on day 11 after implant with no treatment difference. However after implant removal the values for the LP ewes returned to 100\% by day 17 while for the HP and phenobarbital group values remained at 33\%. In Trial 2 the levels 4 days after implant insertion were 37\%, and 48\% for the HE and LE ewes. Again protein treatment delayed recovery following implant removal. These results do not support the hypothesis that the increased ovulation rate following protein supplementation is due to a reduction in negative steroid feedback on FSH levels. }, issn = {1176-5283}, author = {Willis JA and Bickerstaffe R and Munro JM and O{\textquoteright}Connell D} } @conference {40193, title = {Comparative nutrition of deer and goats, goats and sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {39-42}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied }, issn = {1176-5283}, author = {Domingue BMF and Dellow DW and Wilson PR and Barry TN} } @conference {40212, title = {Comparison of commercial gonadotrophins using bioassays}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {161-166}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The immune response of sheep to nematode parasites involves a cascade of events beginning with the recognition of nematode antigen, followed by stimulation of the immune system to elicit the appropriate cellular response at the gut mucosa and finally the release of products which promote the elimination of the parasite from the gut. These processes are examined and deficiencies in the knowledge are highlighted. The application of the knowledge of the sheeps{\textquoteright} immune system to the identification of a marker for resistance and opportunities for the control of nematodes through manipulation of sheeps{\textquoteright} responsiveness are discussed. The progress that has been achieved in the experimental breeding of sheep for nematode resistance is examined. The use of such valuable scientific resource flocks for studies which advance the understanding of the immunology of resistance is discussed. }, issn = {1176-5283}, author = {Henderson KM and Weaver A and Wards RL and Lun S and McNatty KP} } @conference {40247, title = {Comparison of growth and carcass traits of ram lambs of three breeds from a flock screened for prolificacy and a Romney control flock}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {397-402}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {This paper reviews the application of intraruminal chromium controlled release capsules (CRC, Captec (NZ) Ltd, Auckland) to the measurement of herbage intake in ruminants. The capsules are designed to provide for the linear release of Cr2O3 over c. 25 days in sheep and c. 20 days in cattle. Uniform release of Cr2O3 is achieved 2 to 3 days after oral administration of the CRC but steady state levels of Cr2O3 in the faeces are usually not achieved until day 7 or 8 in sheep and day 5 or 6 in cattle. Where cross-over or multiple feeding level experimental designs are applied, time should be allowed for Cr2O3 to adjust to a new steady state in the faeces before sampling for each new treatment. The period of time required varies from 3 to more than 5 days depending on the size of feed intake change. The continuous mode of marker release in the rumen reduces diurnal variation of Cr2O3 in the faeces and this allows rectal sampling regimens to be applied at different times of each sampling day. Sward sampling of faeces reduced disturbance of animal grazing to a minimal level since Cr2O3 is delivered by a single CRC application. The effects of level of feed intake and feed type on the rate of Cr2O3 release are usually small, but release rates may be up to 13\% lower in rumen-fistulated than in non-fistulated animals and may differ for capsules of the same time applied to different ruminant species. Reduced animal handling, flexible faecal sampling times and lower labour requirements with CRC technology, compared to daily drenching of Cr2O3, enable the number of experimental animals to be increased. This improves the likelihood of detecting differences in mean intake between groups. Intakes of individual animals will not be reliably estimated with chromic oxide CRC until the digestibility of herbage consumed by individual animals can be measured more accurately. }, issn = {1176-5283}, author = {McEwan JC and Davis GH and Dodds KG and Fennessy PF and Clarke JN and Hishon M} } @conference {40260, title = {Comparison of herbage intakes estimated from in vitro or alkane-based digestibilities}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {457-459}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied }, issn = {1176-5283}, author = {Dove H and Milne JA and Mayes RW} } @conference {40257, title = {A computational model to predict lamb growth}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {449-452}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Two trials were conducted to study factors which influenced the amount of progesterone (P4) remaining in a CIDR intravaginal device used for a treatment period of 15 days and the associated plasma P4 concentrations. In the first trial, the initial P4 content of these devices was varied from 0 to 2.67g P4. In the second trial, animals were treated with either one or three devices which had been moulded to contain the same amount of P4 (1.9g/device). Increasing the initial P4 content of a device increased plasma P4 concentrations, but at a diminishing rate so that devices containing 1.86g P4 maintained similar levels of plasma P4 to devices containing 2.67g P4 (2.48 vs 2.63 ng/ml). This was associated with a quadratic relationship in the residual P4 content in the used devices. Using three devices per animal trebled plasma P4 concentrations and did not alter residual P4 content. These results indicated that P4 release is influenced more by device characteristics than by animal variation. }, issn = {1176-5283}, author = {Bell ST and Cropper MR and Poppi DP} } @conference {40231, title = {Concentration of melatonin in plasma of goats treated with Regulin}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {297-300}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Sustained release of melatonin from implants or microcapsules administered in October induced cashmere growth during November to March in all ten, treated, cashmere-bearing goats. The mean maximum length of the cashmere in this induced fleece ranged from 12-55mm. Another cashmere growth cycle followed between autumn and winter. In contrast, nineteen control goats grew cashmere only during the autumn-winter period. Melatonin treatment increased total mean cashmere staple length by up to 65\% for treated animals compared with controls. The onset of growth of the autumn fleece in the treated goats was delayed as also was the time when maximum length was achieved on shedding occurred. Melatonin treatment should permit the shearing of the autumn fleece to be delayed, thus reducing the risk of post-shearing losses during inclement weather in late winter. }, issn = {1176-5283}, author = {Parry AL and Paterson DJ and Litherland AJ and Death AF and Staples LD} } @conference {40215, title = {Development and use of gene transfer in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {191-196}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A major factor in the reduction of growth in parasitized lambs is the depression in food intake by a mechanism not yet understood. Investigation of the pattern of eating has shown that parasitized lambs have a lower (35\%) cumulative intake, especially within the first hour of feeding, which return to a control level on drenching. The importance of two factors which may moderate intake depression, the activity of ventromedial hypothalamus (VMH) and elevated cholecystokinin (CCK), were investigated. Four animals with intake depression (approximately 40\% P<0.05) as a result of continuous infection with 4000 T.colubriformis per day for 12 weeks together with 4 control animals received, in a replicated latin square design 0, 1, 2 and 4ml i.v. of a compound (brotizolam) used to block the satiety effect at the VMH. Intake increased (P<0.05) within the first hour of feeding of both parasitized and control animals (approximately 2.6 and 1.9 times, respectively). Four similarly infected and 4 control lambs were given varying doses of a potent antagonist of peripheral CCK action without effect on food intake. These results suggest that depression of food intake in parasitized lambs appears to involve central satiety signals and not peripheral CCK. }, issn = {1176-5283}, author = {Bullock DW} } @conference {40206, title = {Developments in artificial insemination and controlled breeding in dairy cattle and deer in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {123-134}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A number of techniques for directly manipulating the mammalian germline have been established in the mouse. During the past five years these have been applied to domestic livestock but, so far, only pronuclear microinjection has proved successful. The considerable resources required and the low efficiency of the procedure are major limitations and, worldwide, relatively few laboratories have produced transgenic livestock. In applying rtransgenic technology to farm animals, a major effort has gone into the manipulation of growth. This is a complex trait and progress has been constrained by the inability to control the expression of transgenes in a precise manner, and by the lack of basic knowledge at the interface between molecular biology and physiology. By contrast, the production of biomedical proteins from transgenic animals involves the manipulation of a relatively simple trait, milk composition. So far, only relatively low levels of protein production have been reported for transgenic sheep. However, very high levels of expression of human a1-antitrypsin have been obtained in transgenic mice, demonstrating the feasibility for this application of transgenic animals. }, issn = {1176-5283}, author = {Macmillan KL and Asher GW} } @conference {40214, title = {Developments in domestic animal embryo manipulation technology which support the application of molecular biology to animal production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {181-190}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A simulation model for mixed infections of gastrointestinal nematodes in lambs was used to compare with a series of extended drenching programmes. The model output concurs with the results of field trials showing that preventive drenching will control parasites adequately except when autumn conditions are particularly favourable for development and migration of larvae onto pasture. The model suggests that the level of pasture contamination in spring will have a significant influence on parasite control throughout much of the year. A reduction in pasture contamination was simulated by the addition of a post-lambing ewe drench prior to the preventive lamb drenching programme. This gave better parasite control and increased production compared with extended drenching of lambs in the autumn. This is likely to be the result of reduced larval challenge. These model predictions will require validation in the field. }, issn = {1176-5283}, author = {Tervit HR and Thompson JG and Peterson AJ} } @conference {40251, title = {DNA profiling in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {417-422}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied }, issn = {1176-5283}, author = {Crawford AM and Buchanan FC} } @conference {40194, title = {Effect of duodenal infusion of protein or amino acids on nitrogen retention of lambs consuming fresh herbage}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {43-47}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The first two years of a breeding trial have shown that sires with slow clearance of glucose after a glucose tolerance test will produce progeny with similar slow clearance and leaner carcasses (Line 1), than progeny from sires with fast glucose clearance (Line 2). Six extreme animals from each Line were selected to study the biochemical mechanisms controlling the effects seen in the breeding trial. An euglycaemic clamp experiment involved infusing insulin at three levels, 0.63, 3.46 and 6.29 mU/kg liveweight 0.75/min, each for four hours. At the same time glucose was infused with adjustments to maintain plasma glucose at basal levels. The amount of glucose infused is a measure of the sensitivity of the peripheral tissues to insulin. Line 1 animals required significantly (P<0.05) more glucose to maintain euglycaemia during all three levels of insulin infusion. Because there were differences in basal plasma glucose (Line 1:71, Line 2:61 mg/100ml, P<0.05), glucose utilisation was corrected for basal glucose. Line 1 animals still had greater glucose utilization. Another measure of insulin sensitivity is the change in glucose utilization relative to the change in plasma insulin as insulin infusion increases. Line 1 animals had a significantly greater insulin sensitivity index than Line 2 animals (0.505 versus 0.193, P<0.01) for the change from level 1 to level 2. When corrected for differences in basal glucose, Line 1 animals were still significantly more sensitive to the increase in insulin (0.680 versus 0.346, P<0.01). Selecting animals for breeding by glucose tolerance produces sheep with differences in glucose utilization by peripheral tissues. These biochemical differences are important in partitioning nutrients for deposition of lean or fat tissue. }, issn = {1176-5283}, author = {Fraser DL and Hamilton BK and Poppi DP} } @conference {40266, title = {The effect of early exposure to facial eczema on ewe lifetime production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {473-475}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied }, issn = {1176-5283}, author = {Moore RW and Sumner RMW and Dow BW} } @conference {40220, title = {The effect of endoparasitism on host nutrition - the implications for nutrient manipulation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {237-244}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Colostrum is an essential post-natal energy source. We have investigated the link between lamb serum immunoglobulin concentration and colostrum intake as a means of estimating lamb energy intake. Thirty previously unsuckled Coopworth and Corriedale lambs were bottle fed fresh colostrum at 60, 135, 210 or 285 ml/kg birth weight 24 hr in equal feeds at 2 or 4 hour intervals from birth to 30 hours after birth. IgG in serum was measured before first feeding and then at 8 hour intervals to 32 hours after first feeding by ZnSO4 turbidity. Prior to feeding mean serum IgG concentration of the lambs was 0.41}, issn = {1176-5283}, author = {Poppi DP and Sykes AR and Dynes RA} } @conference {40225, title = {Effect of increasing Fe intake on the Fe and Cu content of tissues in grazing sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {265-268}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The fleeces of 30,000 ewe hoggets from 12 Merino flocks were sampled and the mean fibre diameter and clean fleece weight were measured in 1987 and 1988 and the best were selected to establish a superfine joint venture (SFJV) flock of 307 breeding ewes. The breeding objective is to achieve mean fibre diameter below 17um in the adult fleece while maintaining fleece weight and live weight. Concomitantly, a random control flock (RC) of 101 ewes was constituted from the flocks screened. Both flocks are farmed on MAF Technology{\textquoteright}s high country station at Tara Hills, Omarama. The screened SFJV flock has significantly lower live weight (p<0.01), greasy fleece weight (p0.05), loose wool bulk (p<0.001) and mean fibre diameter by 2 um (p<0.001). Staple length (P<0.001), staple crimp (P<0.05) and yield (P<0.05) were significantly higher for the SFJV flock compared with the RC flock. Wool returns of SFJV flock were $81.78/hd and $107/hd vs $62.21/hd and $47.00/hd for RC flock in 1988 and 1989 shearing respectively }, issn = {1176-5283}, author = {Grace ND and Lee J} } @conference {40209, title = {Effect of oestradiol implants and protein nutrition on plasma FSH levels in ovariectomised ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {145-148}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The possible impact of developments in artificial insemination (AI), multiple ovulation and embryo transfer (MOET), sexed semen and embryos, cloning, physiological markers, genetic markers and transgenic livestock on rates of genetic change are reviewed and discussed. Previous theoretical predictions have exaggerated the potential increases in rates of genetic change available from MOET, particularly in small, closed MOET nucleus schemes. Sexing of semen and/or embryos has a relatively small effect on rates of genetic change, but sex control can potentially have a dramatic effect on the efficiency of farming systems. Developing techniques to produce large clone families in livestock will increase rates of genetic change, particularly through faster dissemination of superior genotypes to commercial populations. A cost-benefit analysis of some different strategies for increasing genetic change in the New Zealand dairy cattle population has identified that useful contributions could come from AI (by doubling current bull coverage) and from MOET and genetic and/or physiological markers. Equally important economic returns were identified from increasing the number of bull mothers continuously bred by AI. The impact of transgenic animals, gene mapping and genetic markers (linkage) on rates of genetic change is likely to take much longer (10- 20 years) than the reproductive techniques. }, issn = {1176-5283}, author = {Smith JF and Cruickshank GJ and Payne E and Konlechner J and Parr J and McGowan LT and McLaughlin RR} } @conference {40267, title = {The effect of pre-mating feeding level and age on liveweight change on reproductive performance of cashmere does}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {477-478}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The results in this field over the last 10 years at Ruakura and relevant international data is reviewed. The nutrients involved have been defined and a likely mechanism of action indicated. Pasture allowance experiments indicated effects of pasture quality and a series of pellet feeding trials defined effects of both energy (linear) and protein (threshold) intakes. The threshold effect of protein was confirmed by the abomasal infusion of protein. Analyses of changes in blood concentrations of amino-acids indicated the involvement of the branched-chain amino-acids (BCAA) and this has been confirmed by an increased ovulation rate after intravenous infusion of BCAA. It is concluded that the static and dynamic liveweight and the immediate nutrient effects are the same response measured at different times. The rate at which the response develops is dependant on the type of feedstuff. Studies into the mechanism of action in both intact and ovariectomised ewes have ruled out effects on pituitary release of FSH either directly or via interference with negative feedback influences. This indicates that the effect is at the ovarian level and is mediated either by direct action of the BCAA or indirectly via a metabolic hormone. }, issn = {1176-5283}, author = {Parry AL and Edmonds DK and Knight TW and Hamilton GJ} } @conference {40237, title = {Effect of shearing once-yearly in January, once-yearly in July or twice-yearly in January and July on ewe performance}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {329-334}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The major challenges facing the sheep industry are improving animal performance, minimising disease, reducing labour, and being attuned to consumers{\textquoteright} long term needs. Solutions will involve new technology in sheep breeding, biological disease control and novel approaches to reducing labour associated with sheep. Environmental, health and welfare issues are shaping up to be major consumer issues by the 21st century and production techniques will come under closer scrutiny in future. }, issn = {1176-5283}, author = {Sumner RMW and Scott ML} } @conference {40210, title = {The effects of nutrition oestradiol, phenobarbital and carbon tetrachloride on ovulation rate and plasma FSH in ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {149-154}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Recent advances in the genetic manipulation of animals have raised some familiar and some less familiar ethical issues. The obligation to safeguard the welfare of animals must be extended to include the production of transgenic animals, to ensure that the well-being of such "products" takes precedence over profitability. Human welfare must also be safeguarded especially in relation to the equitable distribution of the benefits from genetic engineering and the protection of the environment. The change in the relationship between human and non-human animals, exemplified in the patenting of genetically modified animals, has serious implications for the integrity of animal science. }, issn = {1176-5283}, author = {Payne E and Smith JF and Peterson AJ and McGowan LT and Cope BC and McLaughlin R} } @conference {40265, title = {Effects of varying the progesterone content of CIDR intravaginal devices and multiple CIDR treatments on plasma hormone concentrations and residual hormone content}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {471-472}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied }, issn = {1176-5283}, author = {Macmillan KL and Washburn SP and Henderson HV and Petch SF} } @conference {40195, title = {Estimation of the pasture horizons grazed by cattle, sheep and goats during single and mixed grazing}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {49-53}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The nutritional treatment of lambs influences the extent of carcass fat deposition. Suckled lambs deposit more fat than weaned lambs with associated increases in plasma glucose and insulin levels. To investigate the mechanisms involved, groups of lambs with different insulin profiles were created, either nutritionally or by infusing insulin, and the effect on carcass composition determined. Border Leicester x Dorset lambs were either weaned at 5 weeks of age or remained suckling with access to grass. Twenty four lambs were slaughtered at 12 weeks of age, the remaining lambs were slaughtered at 23 weeks of age. A subset of both weaned and suckled lambs were treated with exogenous insulin from 5 weeks until slaughter. Insulin status was assessed by the glucose tolerance test and by the response of plasma glucose to injected insulin. The prolonged suckling of lambs increased carcass fatness and decreased carcass protein compared to early weaned lambs. Infusing insulin decreased carcass fatness and increased carcass protein. The alterations in carcass composition were associated with changes in the sensitivity of peripheral tissues to insulin. }, issn = {1176-5283}, author = {Nicol AM and Collins HA} } @conference {40217, title = {Ethics and animal production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {211-214}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Research has shown some dairy cows show temporary falls in plasma calcium concentration during the first six weeks of lactation. By monitoring plasma calcium concentrations in 58 dairy cows in 4 herds for 42 days postpartum it was found that 33\% showed at least one episode of a fall in plasma calcium concentration to <1.9 mmol/l. The mean plasma calcium concentration of these cows during this period was 2.15 mmol/l compared to 2.60 mmol/l for those cows which maintained plasma calcium concentrations above 2.10 mmol/l for six weeks and 2.35 mmol/l for another group which maintained plasma calcium concentration above 1.9 mmol/l but not always above 2.1 mmol/l. These mean calcium concentrations differed significantly (P<0.001) among the three groups and between sampling days after calving. There was no significant association between herd and distribution of cows in each group and age of cow was not significantly correlated with plasma calcium concentration on days 7, 9, 19, 29 and 42 after calving or with the overall mean concentrations. Sub-clinical hypocalcaemia may commonly occur in early lactation and have significant effects on production and reproduction in dairy cows. }, issn = {1176-5283}, author = {Campbell AV} } @conference {40254, title = {Experiences in the application of embryo bisection in sheep MOET programmes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {431-436}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Hypervariable DNA probes can be used to detect a series of polymorphic markers that are stably inherited and potentially useful in genetic analysis. We have determined the amount of informative polymorphism that would be revealed by these probes if genetic crosses were to be created within and between flocks of Romney sheep selected for resistance and susceptibility to facial eczema. }, issn = {1176-5283}, author = {Wells DG and Thompson JGE and Tervit HR and James RW and Udy GB} } @conference {40197, title = {Exploiting the physiology of growth}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {59-72}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The response of ram lambs from the Massey university backfat selection lines to a urea load were measured in order to ascertain whether there were line effects on urea space and to evaluate relationships between urea space and empty body water content. Thirty- six 6-8 month-old ram lambs held in metabolism crates and fed lucerne chaff at 1.3 maintenance, were given 120mg urea/kg through jugular catheters. Plasma urea levels were measured in samples taken before and after the urea load. All animals were slaughtered within 7d of the urea challenge and total body water was determined. In contrast to previous studies, baseline plasma urea levels were not significantly higher in the high-backfat-line animals and were not related to carcass fat or water content. The increases in urea levels following the urea load were greater for the high backfat line at 15min, but not at subsequent sampling times. Clearance rates following the load did not differ between the lines. Correlations between empty body water and estimates of urea space were low, suggesting that this is not a useful means of obtaining body composition information for live sheep at this stage. Urea space estimated in several ways was significantly higher for the low backfat line group. }, issn = {1176-5283}, author = {Buttery PJ and Dawson JM and Harper JMM} } @conference {40223, title = {Facial eczema in Jersey cattle: heritability and correlation with production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {255-260}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Fifty-eight possums (28 male, 30 female) were captured from the wild. Animals were grouped into ages of 1, 2-4 and 5+ years. Males were always heavier than females of the same age, while carcass weight increased significantly with age up to 5+ years. Age had a more pronounced effect on carcass composition and meat quality than sex. At all ages, and in both sexes, possums produced carcasses which were high in dissected lean (78-80\%) and low in fat (0.8-2.6\%). Their meat was very high in protein (24-26\%) and low in fat (1.4-2.0\%). Tenderometer results showed that all age groups produced meat which would be rated as acceptably tender. }, issn = {1176-5283}, author = {Morris CA and Towers NR and Tempero HJ and Cox NR and Henderson HV} } @conference {40253, title = {Factors influencing the success of a large scale artificial insemination programme in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {427-430}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Two experiments were conducted to compare PMSG injection to GnRH infusion for induction of breeding in anoestrous ewes. In Experiment One, sixteen Suffolk ewes were pre-treated for 14 days with 30 mg Cronolone sponges. At sponge removal half of the ewes received 0.125 ug/hr GnRH for 72 hours via subcutaneous osmotic pumps. The other half received a single injection of 750 iu PMSG. Plasma LH levels gradually increased and were sustained for 24 hours. Estrus, ovulation and corpus luteum function were expressed in half of the ewes treated with GnRH. All ewes treated with PMSG exhibited estrus, ovulated and formed functional corpora lutea. In Experiment Two, 24 ewes were divided into two groups and the same treatments as in Experiment One were applied. Fertile rams were introduced to all the ewes at the time of sponge removal. Estrus was detected in 75\% of the GnRH treated ewes vs 100\% in PMSG treated ewes. Lambing rates were 44\% and 56\% in GnRH and PMSG groups respectively. These results suggest that the induction of fertility using continuous infusion of GnRH is encouraging. However, other GnRH delivery systems should be investigated. }, issn = {1176-5283}, author = {Shackell GH and Kyle B and Littlejohn RP} } @conference {40272, title = {Feasibility of intensive artificial insemination programmes using natural oestrus subsequent to synchronisation with CIDR-G in Merino ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {493-494}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Genetic variation among 7 sheep breeds was investigated using 10 DNA probes. No significant differences were observed between Romneys, Coopworths and Perendales at any of the loci examined. Significant variation was observed between Romney related breeds and Merinos at several loci. At the haemoglobin locus (Hb), a probe which appears to detect alleles coding for HbA and/or HbB as classified by protein electrophoresis, failed to detect alleles in all samples. The missing allele appeared predominant in Texel DNA samples, but was also seen in Romneys, Coopworths and Merinos. A new allele was detected in Texel DNA with a probe coding for the Beta subunit of follicle-stimulating hormone (FSH-Beta). This allele was observed at a high frequency in the Texel population and may be Texel specific. Similarity of allele frequencies between the Gotlands and Finns at many loci suggests that these two breeds may be related. Texels and Merinos do not appear to be closely related to any of the breeds studied. }, issn = {1176-5283}, author = {van Reenen GM} } @conference {40261, title = {Fertility of anestrus ewes infused with gonadotropin releasing hormone or injected with pregnant mares{\textquoteright} serum gonadotropin}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {461-464}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied }, issn = {1176-5283}, author = {Hamra AH and Wheaton JE and Marcek JM} } @conference {40189, title = {Fifty years and the future}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {1-6}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Eleven rising 2 year old red deer stags (127 kg LW) and five yearling steer (297 kgLW) were used to examine and compare pasture dry matter and water intake when grazing a rapidly decreasing pasture mass. The two groups grazed separately on adjoining 0.024 ha paddock breaks (12 per group) for 3 day periods. Mean pre and post-grazing pasture mass for both groups was 3400 (+/-80) and 1100 (+/-40) kg DM/ha. Pasture intake (g DM/kg LW0.75/d) for stags and steer respectively was 65, 93 (day 1) 44, 45 (day 2) 28, 25 (day 3). Results indicate that at pasture allowances greater than 4.0 kg DM/100 kg LW comparatively higher intake was achieved by steers. Daily pasture intake, expressed as a proportion of initial pasture intake (day 1), of stags was less affected by decreasing pasture mass (days 2 and 3) than steers. Voluntary water intake by stags was approximately one sixth that of steers (3.6 vs. 23.2 1/hd/d). When compared on the basis of 1/kg LW0.75/d, steers consumed 3.4 times more water than stags. Faecal dry matter content (\%DM) differed between species, being 25.6\% for stags and 14.7\% for steers. These results indicate faecal water loss may be a major factor contributing to higher water consumption by steers. }, issn = {1176-5283}, author = {Jury KE} } @conference {40274, title = {The First 50 Years}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {499-504}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Coop IE} } @conference {40232, title = {Fleece weight and wool characteristics of Merino ewes screened into a superfine selection flock}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {301-304}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {One hundred and eighty cashmere wethers were divided into 11 treatment groups with 9 groups receiving a single melatonin implant at various dates staggered 6 weeks apart throughout the year commencing on 22 January 1988 and finishing on 22 December 1988. The tenth group received a melatonin implant at each of the treatment dates. The control group received no implant. Down lengths were collected at 1 to 6 weekly intervals to monitor growth patterns. The continuous melatonin treatment resulted in lower peak down lengths than controls in August while down lengths were higher than controls from October to January. However the period of down growth was unchanged. Shedding of down occurred 19 weeks after melatonin treatment in all groups except those treated on 15 April, 7 July and 18 August where the interval to shedding was shorter and in phase with the natural shedding cycle. Cashmere growth was only initiated following melatonin treatment from 18 August to 22 December. Treatment on 10 November increased cashmere production by 32 \%. This was the only treatment which increased cashmere production harvested in one season. }, issn = {1176-5283}, author = {Wuliji T and Land JTJ and Andrews RN and Dodds KG} } @conference {40216, title = {The future impact of new opportunities in reproductive physiology and molecular biology on genetic improvement programmes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {197-210}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {During the serious outbreak of facial eczema (FE) in 1989, blood samples were obtained from first-lactation heifers born in 1986, in order to study any genetic influence on the incidence of FE. Heifers were located in 60 herds in Northland (14 herds), Auckland (25) and Taranaki (21). The herds were members of the New Zealand Dairy Board{\textquoteright}s 1985 Sire Proving Scheme for young Jersey bulls. Samples were collected from 1523 heifers, the daughters of 57 young Jersey sires and 19 other Jerseys including reference sires from previous years. Blood samples were analysed for gamma-glutamyltransferase (GGT), an indicator of liver damage such as due to FE. Overall, 28\% of animals had elevated GGT values (>=30IU/1), and 72\% (43) of herds had 2 or more animals with elevated GGT. After setting aside data from the 17 herds where no elevations of GGT concentration were recorded, the heritability of log e GGT was 0.31}, issn = {1176-5283}, author = {Baker RL and Shannon P and Garrick DJ and Blair HT and Wickham BW} } @conference {40262, title = {Genetic analysis in sheep using hypervariable DNA probes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {465-466}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied }, issn = {1176-5283}, author = {Hermans IF and Chambers GK and Jordan TW} } @conference {40248, title = {Genetic parameters for in vivo body measurements in Suffolk sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {403-406}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Attention is drawn to developments in the public perception of animal farming which have the potential to adversely affect the animal industry in the future. These developments, which are occurring around the world, stem from review of ethical aspects of animal farming and from concern at the ecological impact of animal farming. Of particular concern is the emission of greenhouse gases - especially methane - by ruminants. This paper discusses measures by which these emissions could be reduced, and how national policy decisions regarding greenhouse gas emissions on farms may be reached. Opportunities for this Society are pointed out. }, issn = {1176-5283}, author = {Young MJ and Simm G} } @conference {40213, title = {The germline manipulation of livestock: progress during the past five years}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {167-180}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The role of endoparasitism on host nutrition was reviewed and the opportunities for manipulation considered with emphasis on two specific nutrients for which information is becoming available-protein and copper. The major effect of parasitism on protein metabolism is to increase the protein requirement of the host as a result of increased endogenous loss of protein rather than malabsorption per se. Protein supplementation has been shown to increase liveweight gain of infected sheep and to reduce faecal egg counts and worm burdens probably reflecting enhanced immunological competence of the host. Such rates of protein supply could be achieved in practice on temperature pastures if protein losses across the rumen could be reduced. Liver copper levels have been shown to be depressed by parasitism in the abomosum. The effectiveness of oral copper supplements depends on their ability to increase soluble copper levels in abomasal digesta, which is reduced by nematode-induced increase in pH. Intake depression has by far the greatest effect on production loss due to endoparasitism. Evidence is emerging that the mechanism for this depression has a peripheral hormonal and central neural basis. It was concluded that specific nutrient manipulation in plants or via supplements may enable the host to cope better with the debilitating effects of endoparasitism. }, issn = {1176-5283}, author = {Clark AJ and Archibald AL and McClenaghan M and Simons JP and Whitelaw CBA and Wilmut I} } @conference {40238, title = {Goat fibre response to melatonin given in spring in two consecutive years}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {335-338}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied }, issn = {1176-5283}, author = {Welch RAS and Gurnsey MP and Betteridge K and Mitchell RJ} } @conference {40200, title = {Growth responses of fat and muscle in the lamb to intra-arterial infusions of bovine insulin - Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {91-92}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The purpose of this paper is to summarise recent findings on the reproductive physiology of the Booroola ewe, with specific attention to factors influencing ovulation-rate (OR). The ovarian antral follicle populations, incidence of atresia, steroid secretion-rate and maximum OR potential in the different Booroola genotypes (FF, homozygotes; F+, heterozygotes; ++, non-carriers) are the same notwithstanding the fact that FF, F+ and ++ animals normal ovulate >=5, 3-4 and 1-2 follicles respectively during each oestrous cycle. Moreover, the Booroola F gene does not appear to modify the characteristics of the follicle- stimulating hormone (FSH) or luteinizing hormone (LH) receptors, or the gonadotrophin-sensitive components of the cyclic AMP generating system or the steroid or inhibin biosynthetic functions in follicular cells. It seems that the F gene influences follicular growth before antrum formation resulting in fewer granulosa cells at all phases of antral growth and smaller sized follicles at ovulation. In essence, the >=5, 3-4 or 1-2 presumptive preovulatory follicles in FF, F+ or ++ ewes are respectively 2.5-4.5 mm, 4-5mm and >5 mm in diameter just before ovulation but the total populations of oestrogen-secreting follicular or progesterone-secreting luteal cells in the different genotypes are the same. These genotypic differences in ovarian characteristics have not bee replicated by any of the known superovulation regimes. At the level of the hypothalamus and pituitary no gene-associated differences have been noted in the concentrations of gonadotrophin- releasing hormone (GnRH) in the tissues or hypophyseal portal blood nor in the binding characteristics of GnRH to the pituitary gland. However F gene-specific differences have been noted in the plasma concentrations of FSH and LH in ovary-intact and ovariectomized (OVX) Booroola ewes (FF>++; P,0.05). The F gene-specific differences in FSH but not LH in OVX ewes can be replicated by exogenous GnRH treatment of OVX ewes deficient in endogenous GnRH following surgical disconnection of the hypothalamus from the pituitary gland but with the superior hypophyseal arteries being left intact. The greater frequency of high FSH values in ewes is also observed in both intact and castrate Booroola FF rams relative to ++ rams at P<=0.07. When considered altogether the evidence suggests that Booroola sheep with the F gene have higher mean FSH concentrations in plasma relative to ++ sheep. However the differences are small with considerable overlap between animals of the different genotypes. It therefore remains to be established whether modest increases in plasma FSH concentrations in ++ Booroola ewes are sufficient to modify follicular morphology and OR without altering steroid secretion. }, issn = {1176-5283}, author = {Wolff JE and Petrie DR} } @conference {40273, title = {Hogget fleece weight and fleece characteristics of Texel x Romney, Texel x Coopworth, Romney and Coopworth sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {495-498}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {This study investigated apparent reproductive failure occurring in seasonally anoestrous progesterone-primed red deer hinds when they were induced to ovulate with the GnRH analogue, buserelin. In March 1988 (non-breeding season), each of 11 progesterone-primed red deer hinds(Groups B and BO) were injected i.m. with 4, 3, 2, 2 and 10 ug buserelin (Receptal, Hoechst) at -48, -24, 0, 24, and 48 h relative to the time injected i.m. with 500 ug oestradiol benzoate. During the breeding season (April), ovulation was synchronised in another 4 hinds (Group C) using CIDRs. Oestrous behaviour was less noticeable and delayed (P>0.05) in Group B hinds and peak LH levels were lower (P>0.01) and occurred later (P>0.01) relative to Group ), BO and C hinds. Two weeks after CIDR withdrawal 3/5 B, 2/4 O, 3/6 BO and 4/4 C hinds had a corpus luteum present. During theses two weeks plasma progesterone levels were elevated in B, BO and C hinds but were low in the O hinds. None of the buserelin- and/or oestradiol-induced ovulations resulted in pregnancy. These results show that ovulations induced in these anoestrous red deer hinds by the use of a GnRH analogue or oestradiol were not accompanied by normal hormonal and behavioural patterns. }, issn = {1176-5283}, author = {Wuliji T and Andrews RN and Davis GH and Farquhar PA} } @conference {40207, title = {How does the F gene influence ovulation rates in booroola ewes? A 1990 perspective}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {135-140}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Currently most transgenic animals are produced by microinjecting DNA into a pronucleus of in vivo derived embryos. This is an inefficient procedure because of the costs of animals, superovulation and surgery, the low numbers of embryos produced, and their poor viability after injection. Thus, in most well run programmes, only about 10\% of injected sheep, pig and cattle embryos result in offspring and only 0.5 to 1\% in transgenic offspring. Methods for improving the efficiency are discussed and it is concluded that effective in vitro maturation (IVM), fertilisation (IVF) and culture techniques and alternative methods of gene insertion (particularly through stem cells or sperm - mediated insertion) would make significant contributions to improved results. Ruakura{\textquoteright}s successful sheep and cattle in vitro oocyte maturation, fertilisation and culture programme and its results are discussed. Recent developments in MOET techniques are discussed and it is concluded that, in the short term, it is possible that more effective multiplication of transgenics could arise from successful IVM/IVF and nuclear transplantation procedures than from significant improvements in current MOET technology. The in vitro produced egg therefore has considerable potential for increasing the efficiency of producing and multiplying transgenics. }, issn = {1176-5283}, author = {McNatty KP and Henderson KM and Fleming JS and Price CA and Clarke IJ} } @conference {40211, title = {Induction oestrus in the ovariectomised red deer with exogenous progesterone and oestradiol benzoate}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {155-160}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Preventive control programmes for nematode infections of sheep, which depend upon strategically timed treatments of anthelmintics, are based on epidemiological knowledge of the time relationships between contamination of pastures and seasonal availability of infective larvae in different climatic regions. In Australia by the time these programmes were being actively promoted resistance to two of the three families of anthelmintic drugs had already emerged. A high prevalence of resistance is now widespread in Australia and measures for the management of resistance have been incorporated into recommendations of worm control. These include, a reduction in frequency of treatments, elimination of underdosing, assessment of effective drugs, their use at high dose rates in an annual rotation and the integration of treatment with grazing management. Nevertheless, there is concern that preventive control programmes may not be sustainable over the long term. Increased attention is now directed to alternative means of control, such as vaccination of sheep against nematode infections and breeding sheep with enhanced resistance to infection. The integration of these measures into preventive control programmes and the extent to which they can replace chemotherapy are topics for ongoing study. }, issn = {1176-5283}, author = {Meikle LM and Fisher MW} } @conference {40201, title = {The insulin status of sheep with genetic differences in glucose tolerance and carcass composition}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {93-96}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Twenty four Coopworth ewes, selected on the basis of an increased ovarian response to lupin grain supplementation, were ovariectomised and fitted with a Foley catheter in the abomasum. They were individually penned and offered a low protein pelleted diet at maintenance levels. Following a five week stabilisation period 12 ewes were infused abomasally with 100g/d whey protein concentrate in 1 litre of water for 8 days. Twelve ewes received 1 litre of water only. Blood samples were collected four times daily for FSH analysis, from 2 days before until 2 days after infusion. Protein infusion did not influence FSH levels. Mean values were 8.5 ngFSH/ml plasma for both treatments and means for individual ewes ranged from 4.5 to 11.5 ng/ml. These results indicate that the reported increase in FSH with increased protein intake is not due to a direct effect on the pituitary gland. }, issn = {1176-5283}, author = {Francis SM and Bickerstaffe R and O{\textquoteright}Connell D} } @conference {40255, title = {Intraruminal chromium controlled release capsules for measuring herbage intake in ruminants - a review}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {437-442}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied }, issn = {1176-5283}, author = {Parker WJ and Morris ST and Garrick DJ and Vincent GL and McCutcheon SN} } @conference {40259, title = {Magnetic resonance imaging of live pigs to assess body composition}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {455-456}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Two hundred 2-tooth (2T) and mixed age (MA) cashmere does were randomly allocated to one of 4 feeding levels to evaluate the effect of pasture allowance on liveweight change and reproductive performance. Pasture allowances of 0.8 (L), 1.2 (M), 2.5 (M+) and 5.0+ (H) kgGM/hd/d were imposed for 8 weeks prior to mating. Does were weighed fortnightly and laparoscroped at 10 (CL10) and 20 (CL20) days post buck introduction. Weight change over 8 weeks was -2.2kg (L), 0.1kg (M), 0.3kg (M+) and 1.8kg (H) and was significant (P<0.01) for L, M+ and H treatments. Pasture allowance had no effect on proportion of does ovulating (CL10 and CL20) but does on the L and M allowance averaged fewer multiple ovulations than does on the M+ and H allowances (14\% vs 23\%) at day 10 after mating. A high proportion (P,0.01) of MA does were ovulating 10 days after mating (78.7\% vs 58.2\%) and MA does had more multiple ovulations at 10 (52.1\% vs 11.3\%) and 20 (40.2\% vs 13.5\%) days after mating than 2T does. There were more (P<0.01) MA does pregnant (76.3\% vs 57.1\%) and more multiple pregnancies in MA does (44.6\% vs 17.3\%) than 2T does. This trial showed that age is a major factor in determining proportion of multiple ovulations and multiple pregnancies in cashmere goats. It highlighted the confounding effect of age on liveweight and the difficulty in separating the effects of pasture allowance from the effects of liveweight, on reproductive performance. }, issn = {1176-5283}, author = {Davies AS and Baulain U and Henning M and Kallweit E} } @conference {40258, title = {Mating performance of Texel rams}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {453-454}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Romney, Coopworth and Perendale ewes were accidentally exposed to facial eczema before May 1 hogget mating at 9 months of age. Serum gamma-glutamyl transferase (GGT) levels of individual animals were determined on 21 April. The ewes were divided into 3 classes for analysis based on the GGT levels: 1.<100 IU/1;2. 100-350 IU/1; and 3.>350 IU/1. At all matings over 4 years the ewes in class 3 had a lower fertility than class 1. These differences were only significant at the hogget and two-tooth mating. The total number of lambs weaned per ewe mated were class 1-5.0; class 2-4.4; and class 3-4.3 (P<0.1). There were no lifetime effects on fleece weight. }, issn = {1176-5283}, author = {Davis GH and Knight TW and Sorenson E and Shackell GH and Holmes MR and Farquhar PA} } @conference {40227, title = {The measurement of serum immunoglobulin concentration to estimate lamb colostrum intake}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {275-278}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Sixty-four wild possums, housed in individual cages, were divided into four groups based on sex and colour phase (dark or grey). The animals were assessed for fur quality and growth in March and were pair-matched for sex, colour phase, fur quality and growth. One possum from each pair was implanted with a 18 mg melatonin implant. By June there was a small improvement in fur quality which was independent of the localised regrowth of patches of missing fur. No overall change in the level of fur growth representing seasonal pelage renewal was recorded. The younger possums had a higher fur quality than older animals (p<0.001) but over the course of the experiment the difference (p0.05) than male pelts. Melatonin had no effect, either on pelt characteristics or on live weights. }, issn = {1176-5283}, author = {Parker RJ and Nicol AM} } @conference {40239, title = {Melatonin for cashmere production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {339-344}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Relative to an industry Romney control line, three lines derived from screening for high prolificacy, consisting of Romneys, Perendales and Coopworths had significantly heavier weaning weights after adjustment for non-genetic factors with weights of 19.9 (100), 22.3 (112), 24.0 (121) and 23.9 (120) kilograms (percentage relative to the Romney controls) for the respective flocks. The differences increase post-weaning and when slaughtered, between 175 and 219 days of age, the carcass weights (kg) were 12.0 (100), 14.3 (119), 16.1 (134), 15.7 (131) respectively for the different strains. Although the base populations of Romneys are not genetically comparable the results suggest that the intensive screening for prolificacy has indirectly resulted in animals capable of more rapid growth to slaughter. The differences between strains in their carcass weight adjusted subcutaneous fat depths were minor except that the high prolificacy Perendales had lower increases in fat depths with increasing carcass weight and had the lowest subcutaneous fat depths at heavy weights. Additionally the high prolificacy Perendales had 2 to 6 percent larger estimated L. dorsi areas than the other genotypes. }, issn = {1176-5283}, author = {Litherland AJ and Paterson DJ and Parry AL and Dick HB and Staples LD} } @conference {40269, title = {Milk production and plasma prolactin levels in spring- and autumn-lambing ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {483-485}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Methane and nitrous oxide produced by farmed ruminants may cause over one third of the potential greenhouse warming which can be attributed to New Zealand. This is a result of high populations of domestic ruminants (mainly sheep and cattle), and the large warming potential of methane and nitrous oxide. New Zealand{\textquoteright}s total greenhouse gas production is an insignificant component of the global total, but this fact cannot be used as a reason to ignore New Zealand{\textquoteright}s contribution. International negotiations have commenced with the aim of producing a treaty to limit global greenhouse gas production by ruminants in New Zealand, and identifies areas needing further research. It concludes that; (1) the accuracy of estimate of greenhouse gas emissions from agriculture needs to be improved; (2) technology to reduce greenhouse gas emissions from ruminants should be developed for, and applied to, New Zealand farming systems; and (3) that equitable methods of implementing limitation policies need to be investigated. }, issn = {1176-5283}, author = {Peterson SW and MacKenzie DDS and McCutcheon SN} } @conference {40226, title = {Milk production by cows grazing on Matua prairie grass (Bromus willdenowii Kunth) pastures maintained under difference}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {269-274}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {From a population of 1270 Coopworth ewe hoggets 70 were selected for high greasy fleece weight (CHFW) at hogget shearing and 50 controls were selected at random (CC). The CHFW ewes were joined in 1987 and 1988 to sires from a Romney high fleece weight (RHFW) flock, also mated contemporaneously within that flock. The CC were mated with commercial Coopworth rams. The CHFW and CC flocks were grazed with the RHFW flock and its control (RC). Results for progeny showed that relative to the RC (100) the greasy fleece weight of the RHFW, CC and RHFW x CHFW were 118, 112 and 125 respectively. Corresponding values for lamb fleece weight were 112, 106 and 121; and for October (12 month) live weight were 106, 109 and 114 respectively. RHFW rams crossed with CHFW ewes generated progeny markedly superior to Romney and Coopworth controls for greasy fleece weight, showing that appropriate breeding programmes can rapidly improve this trait. }, issn = {1176-5283}, author = {Rugambwa VK and Holmes CW and Chu ACP and Varela-Alvarez H} } @conference {40221, title = {A model for nematodiasis in New Zealand lambs: preliminary evaluation of strategies for nematode control}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {245-248}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {During 1989, two groups of weaner red deer stags (n=18) grazed either perennial ryegrass (PRG) or Moata annual ryegrass (ARG) based pastures from mid-May until the end of November. Within each group, animals (n=6) were either not immunised or immunised against melatonin using Freund{\textquoteright}s or Dextran adjuvants. Treatment effects upon winter (W) and spring (S) LWG, proportion of animals attaining target liveweight (93kg; 50kg carcass weight by November 30), pasture composition, voluntary DM intake (VFI), anti-melatonin titres and plasma prolactin concentrations were determined. During winter, LWG (165 v 140 g/day; P<0.05) and VFI (1.62 v 1.20 kg DM/day; P<0.001) were greater for animals grazing ARG than PRG pastures, resulting in a greater proportion of deer attaining the target slaughter weight (60 v 41\%). Organic matter digestibility and N content were higher (P<0.05) for the ARG than PRG pastures during winter. Maximum anti-melatonin titres of 1:15,215}, issn = {1176-5283}, author = {Leathwick DM and Barlow ND and Vlassoff A} } @conference {40203, title = {Neuroendocrine control of growth hormone release in sheep: Effect of dose and route of administration of growth hormone releasing factor on plasma growth hormone levels}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {101-104}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {IN a factorial experiment involving 4 treatment affecting ovulation rate and 20 ewes per cell the effect of oestradiol was dominant, reducing the ovulation rate. In the non-oestradiol treated ewes a positive effect of high protein intake was evident. Phenobarbital increased ovulations in ewes on a low protein diet whilst carbon tetrachloride (CC14) had a slight negative effect only on the low protein diet. Neither phenobarbital or CC14 had any effect on the high protein diet. There was a decrease in plasma FSH at day 11 with oestradiol, protein and phenobarbital and an increase with CC14. Hence an increase in FSH does not always accompany increases in ovulation rate. }, issn = {1176-5283}, author = {Spencer GS and Bass JJ and Hodgkinson SC} } @conference {40236, title = {Nutrition effects on fibre quality in Angora goats during spring}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {323-328}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied }, issn = {1176-5283}, author = {Bigham ML and Bown MD and Clayton JB} } @conference {40190, title = {Nutrition of the grazing ruminant}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {7-27}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Muscle fibres in the adult are giant multi-nucleated cells which originate in the foetus from myoblasts and later fuse to form myotubes. Protein deposition is the balance between synthesis and degradation. The proliferation of cells and protein metabolism is controlled by a variety of growth factors and hormones which in the whole animal influence lean deposition. This endocrinological control of growth can be exploited to enhance lean deposition in animals and some of the currently available and potential methods are reviewed. In most cases data would indicate that the animal must be fed a diet that will allow the increased potential for lean deposition to be expressed. Unfortunately many of the methods which have been shown to be safe for the consumer of the meat and the animal are not permitted for a variety of reasons by many government authorities. Future exploitation of the physiology of growth to enhance lean deposition is likely to be increasingly constrained by political decision; a luxury available to the affluent developed world. }, issn = {1176-5283}, author = {Black JL} } @conference {40199, title = {Nutritional partitioning of growth for productive gain}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {81-90}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Artificial insemination (AI) is widely used throughout New Zealand dairy herds because it is convenient and allows herd owners to utilise semen from intensively selected genetically superior sires. The future focus of AI use will be to synchronise oestrus in maiden heifers and cows to further concentrate seasonal calving patterns. There will also be continued use of progesterone-based treatments to stimulate ovarian activity in anoestrous cows and to increase pregnancy rates in inseminated cows. Aspects of behaviour and marked seasonality in red deer and fallow deer currently present challenges to increasing the use of AI and controlled breeding in these species. It would be preferable to have fawning/calving in spring instead of summer, with or without the use of AI. However, the semen production of stags is best from 4 weeks after the onset of the induced or normal rut. This potentially increases the dependence on deep frozen semen and increases the need for the uterine deposition of sperm to increase sire coverage and achieve satisfactory pregnancy rates. Controlled use of hormones will produce altered calving/fawning dates and developing semen collection/processing techniques will increase the use of AI in deer. }, issn = {1176-5283}, author = {Harris PM and Waghorn GC and Lee J} } @conference {40224, title = {Occurrence and effects of sub-clinical hypocalcaemia in dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {261-264}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The duration of melatonin release from Regulin implants and the diurnal variation in plasma melatonin concentration was investigated in 18 cashmere wethers, divided into 3 treatments: C-control; T-treated with melatonin 18mg Regulin implant on 10.11.88; PT - previously treated with melatonin every 6 weeks for 10 months before receiving an implant on 10.11.88. Mean concentration of plasma melatonin in T remained high 52 pg/ml for up to 42 days after implant, then declined to 8.5 pg/ml at 50 days remaining relatively low for the rest of the sampling period. Goats from PT maintained much high concentration of plasma melatonin 226 pg/ml for 42 days after implant. Control goats showed very low mean concentration at 5 pg/ml. Between animal variation in plasma melatonin concentration was high coefficients of variation were between 100\% and 200\% within all treatments. At 8 days post-implant plasma melatonin concentration of goats in C showed a nocturnal increase averaging 12.5 pg/ml, between sunset and sunrise. The same diurnal fluctations were evident at 29 days post- implant. Goats in treatment T also showed a nocturnal rise in plasma melatonin concentrations with average increases of 15 and 24 pg/ml at 8 and 29 days post implant between sunset and sunrise. It can be concluded that the melatonin implants used in this trial lasted for 42 days after administration and a nocturnal rise in melatonin concentration was evident in control and treated goats. }, issn = {1176-5283}, author = {Daniel RCW and Kerr DR and Mulei CM} } @conference {40264, title = {Oestrus activity in Booroola Merino, New Zealand fine wool Merino and Poll Dorset ewes from October to February}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {469-470}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied }, issn = {1176-5283}, author = {Knight TW and Kannegieter SG and Gibb M and Haack NA} } @conference {40240, title = {The pastoral animal industries in the 21st century}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {345-360}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Performance test data for ram lambs from a selection programme in a Suffolk flock were used to estimate heritabilities for and correlations (genetic and phenotypic) between three variables (liveweight, ultrasonic fat depth (FD and ultrasonic muscle depth in the live animal). Close agreement was found with previously published values with the exception of the heritability for FD for which a high value was estimated (0.55 }, issn = {1176-5283}, author = {Robinson JJ} } @conference {40196, title = {Pasture dry matter and drinking water intake of grazing red deer stags and steers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {55-58}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {There has been considerable interest recently in the use of growth hormone (somatotrophin) to enhance growth, carcass leanness and milk yield in a number of species. Despite the similarity of bovine and ovine growth hormone, the administration of exogenous somatotrophin to lambs has produced disappointing results. Conceivably, stimulation of endogenous GH secretion may be more beneficial, and in this communication we present our preliminary results on the effective doses and rates of administration of growth hormone releasing factor in a study of the neuroendocrine regulation of growth hormone secretion in sheep. Sheep were housed indoors on a complete pelleted diet and were fitted with jugular vein catheters. Some sheep were also fitted with cannulae placed in a lateral ventricle of the brain. Bovine GRF was given at different doses to the sheep either intravenously (iv), intracerebroventricularly (icv) or intramuscularly (im) and plasma GH levels monitored. There was a dose-dependent increase in GH levels when the GRF was given iv, with both 30 and 3 ug being effective, while im administration was only effective at 30 ug. Central administration (icv) was also effective at both dose but did not stimulate GH release at 300 ng. Further studies are required to elucidate the mechanisms underlying GRF stimulation of GH release, but the efficacy of GRF as a growth promoter can be investigated using intramuscular administration. }, issn = {1176-5283}, author = {Alexander GL and Segiura T} } @conference {40191, title = {Plants for grazing systems}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {29-34}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The somatotrophic axis has a major effect on lean growth in a number of species. GH, the main hormone of the somatotrophic axis, is controlled by growth hormone releasing hormone and somatostatin. GH can act directly on fat by increasing lipolysis, but its main anabolic effects are on muscle and bone via the Insulin like growth factor-I (IGF-I). IGF-I stimulates amino acid uptake into muscle in vitro but does not necessarily promote growth if given in vivo. The reason for this is that GH is now considered to control circulating IGF- I as well as local tissue production of IGF-I, the dual effector theory. This theory proposes that GH not only controls IGF-I production but controls differentiation of cells so that they can respond to the mitogenic effects of IGF-I. Insulin is another anabolic hormone which is affected by GH. Insulin, unlike GH, stimulates fat deposition, although it also increases protein accretion. The manipulation of the growth hormone axis by immunological procedures, selection or genetic engineering may provide an economic way for NZ farmers to increase the production of lean meat. }, issn = {1176-5283}, author = {Hodgson J} } @conference {40204, title = {Plasma urea dilution patterns in Southdown ram lambs from high and low backfat selection lines}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {105-108}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Exogenous progesterone and oestradiol benzoate (OB) were used in long-term ovariectomised red deer to investigate a simple technique for induction of oestrus. Up to 12 days of intravaginal progesterone (CIDR-S; replaced at 4 day intervals) was followed 24h later by a single intramuscular injection of OB. Continual observations (for behavioural oestrus) and blood sampling every 6h (for plasma LH concentrations) were conducted over the subsequent 48h period. In Experiment 1 (December), 12 days of progesterone preceded 0, 1.0, 2.5 or 5.0 mg OB. Onset of oestrus (28-44h post-OB; mean 33h) was similar in all treated hinds. Plasma LH concentrations fell (P<0.01) after OB administration, followed 30 to 36h later by a dramatic increase (to 6.4 ng/ml) indicative of pre-ovulatory-like LH surge. Hinds receiving no OB exhibited 4\% of all mounting interactions but showed no increases in LH concentration. Experiment 2 (January) consisted of no treatments or 12 days or progesterone followed by 0, 0.1 or 1 mg OB resulted in suppression of plasma LH after OB. However, all other plasma LH and behaviour responses elicited were anomalous. In Experiment 3 (February), 0,4, 8, or 12 days of progesterone pretreatment were terminated 24 hours prior to administration of 1 mg OB. Plasma progesterone concentrations were elevated above 1 ng/ml during all progesterone treatments. Onset of oestrus was observed later (P<0.5) after 4 days of progesterone treatment (33.4h; sem 1.2h). Tonic plasma LH secretion was elevated (P<0.01) from Experiment 1 through to Experiment 3 but the plasma LH suppression in response to OB was similar in all 3 experiments. These results indicate that oestrus can be induced in the red deer hind by at least four days of intravaginal progesterone treatment followed by i.m. oestradiol benzoate administration 24h after progesterone removal. }, issn = {1176-5283}, author = {Abdullah AY and Purchas RW and McCutcheon SN and Van Dinther PC} } @conference {40229, title = {Postweaning growth and carcass leanness of lambs that differed in preweaning growth rate}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {287-292}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {An experiment was conducted to investigate the effect of nutritional status on fibre quality from Angora goats during spring. Two groups of 28 non-pregnant Angora does were grazed on ryegrass/white clover pasture at one of two pasture allowances; 1.0 kg and >4kg DM /head/day (low and high respectively) for twelve weeks during spring. Groups were balanced for live weight, age, fibre diameter, medullation and kemp measurements and genetic background. Live weight and fibre quality (fibre diameter, \% medullaltion and \% kemp) were measured at the start, after 6 weeks and at the end of the experiment. Mean live weight of does at the start of the experiment was 22.6 + 0.20 kg and after 12 weeks 30.9 and 25.2; sed 0.63kg for high and low allowance respectively. Neither mean fibre diameter (35.2 vs 34.1; sed 0.66 microns) nor medullation (5.38 vs 6.51;s ed 53\%), was affected by pasture allowance over the experiment (high and low allowance respectively). However, after 12 weeks, there was a trend for \% kemp measured in the fleece in does on high pasture allowance to be higher than in does on low allowance (8.16 vs 6.52; sed 1.04\%). All does were fibre tested again in March 1989 after grazing at a common allowance, but differences in fibre characteristics between the previous spring pasture allowances treatments were small. It appears that doe nutrition during spring can influence the kemp content in the Angora fleece. The mechanism of this effect is, however, not known. }, issn = {1176-5283}, author = {Bray AR and Moss RA and Burton RN and Saville DJ} } @conference {40192, title = {Present and future grazing systems}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {35-38}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Various tissues in the sheep, because of their individual specialist roles, have very different nutrient requirements. These differences in metabolic behaviour provide a potential opportunity to manipulate biochemical pathways in specific peripheral tissues to enhance production characteristics and, consequently, commercial gain. Factors affecting such partitioning are discussed with particular reference to the sheep industry in New Zealand, which unlike most other international sheep systems, needs to produce meat and wool from the same animal. Because the relative returns from meat and wool vary from season to season there is a need to manipulate independently their relative production to achieve maximum economic return. }, issn = {1176-5283}, author = {Bryant AM} } @conference {40198, title = {Regulation of growth by the growth hormone axis}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {73-79}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The bovine conceptus induces an array of physiological and biochemical responses that lead to the establishment of pregnancy. Among the most studied of these is secretion of prostaglandin (PG) F2alpha (F) from the uterine endometrium. Pregnancy appears to be associated with laterations in many of the regulatory systems that cause PGF secretion leading to luteolysis in cyclic animals. The conceptus secretes an antiluteolytic protein (bovine trophoblast protein-1 complex [bTP-1] that appears to induce an inhibitor of prostaglandin synthesis. The bTP-1 antiluteolytic protein is an alphaII interferon. The secondary effects associated with interferon-like activities (antiviral, antiproliferative, altered gene expression, immunosuppressive) may complement development and sustenance of the conceptus. Both ovarian CL function and follicular activity are altered in early pregnancy. Changes in follicular activity may reinforce the antiluteolytic signals from the conceptus leading to maintenance of the CL. Potential management systems to improve reproductive efficiency that are based on supplementation with bTP-1-like molecules, controlled ovarian follicular management, and progesterone therapy are discussed. }, issn = {1176-5283}, author = {Bass JJ and Gluckman PD} } @conference {40228, title = {Responses in venison production to grazing pastures based upon perennial ryegrass or annual ryegrass and to immunisation against melatonin}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {279-286}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Annual patterns of fur growth are described from captive possums skin biopsied at three-weekly intervals between April 1985 and May 1987. Counts of hair follicles showed that follicle activity was poorly synchronised between individual possums, with maxima occurring mostly in spring and summer. No more than 40\% of follicles sampled were active at one time in any individual. Derived follicles continued to develop in adult animals, increasing the follicle population by 23 }, issn = {1176-5283}, author = {Ataja AM and Wilson PR and Hodgson J and Hoskinson RW and Purchas RW and Varela-Alvarez H and Barry TN} } @conference {40252, title = {Responses to modern technology within the New Zealand sheep breeding industry}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {423-426}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {In 34 lactating ewes (10 fistulated at the rumen and abomasum), herbage intakes were calculated using herbage digestibilities estimated either in vitro, or by using the plant cuticular wax component pentatriacontane (C35 alkane) as an internal marker. Alkane-based herbage intakes in intact ewes rose from 1672g OM/d at 14d of lactation to 2798g OM/d at 42d. In the fistulated ewes, the equivalent herbage intakes were 1736 and 2240g OM/d respectively. Alkane-based and in vitro-based intakes were not significantly different at 14d of lactation in either intact or fistulated ewes. Later in lactation, alkane-based intakes were significantly higher in both groups of ewes. In the fistulated ewes, estimates of the proportion of digested OM apparently disappearing across the rumen and of the efficiency of microbial protein synthesis were calculated from abomasal flows of digesta and microbial protein. These results suggested that the alkane- based herbage intakes were the more accurate. }, issn = {1176-5283}, author = {Harvey TG and Haydon R and Blair HT and Daniell D and Hilson R} } @conference {40235, title = {Seasonal fibre replacement and harvesting of fur in brushtail possums (Trichosurus vulpecula)}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {317-322}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied }, issn = {1176-5283}, author = {Nixon AJ} } @conference {40219, title = {The sheep{\textquoteright}s immune response to nematode parasites and prospects for its exploitation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {229-236}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Perennial ryegrass (RG) and Matua prairie grass swards of low (LMPG) and high (HMPG) pre-grazing herbage masses were compared in 8 grazing trials (2-3 weeks) during early spring, late spring, summer and autumn (1987/88 and 1988/89) to assess their feeding values. Pre- grazing masses were approximately 3000, 4000 and 5500kg DM/ha for RG, LMPG and HMPG treatments, respectively. Friesian cows (8 per treatment) were allowed 50 kg DM/cow/d. Mean concentrations of N (\% in OM) and OMD (\%) for RG, LMPG and HMPG herbage were 2.7, 2.6, 2.3 (s.e.lsm 0.04, P<0.001); and 74.7, 73.1 and 70.7 (s.e. 0.18, P<0.001), respectively, HMPG values were lowest during all seasons and were influenced by high compositions of dead material, low leaf:stem ratios and low compositions of clover in the swards. Daily yields of milk and protein on RG swards were 3\% higher (P<0.05) than LMPG yields, and 11 and 13\% higher (P<0.001), respectively than those of HMPG swards. Milkfat yields were similar on RG and LMPG swards, but were 11\% lower (P<0.001) on the HMPG treatment. The results indicate that leafy prairie grass and leafy ryegrass swards have similar feeding and productive values. Further research is needed on Matua{\textquoteright}s persistence under grazing. }, issn = {1176-5283}, author = {Douch PGC} } @conference {40208, title = {Studies into the mechanisms by which nutrition influences ovulation rate: use of the ovariectomized ewe model}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {141-144}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Gene transfer offers vast potential for improvements in animal agriculture. Improvements in quantity, quality and efficiency of production as well as entirely new forms of production can be envisage. Realising this potential, however, is hampered by dilution and duplication of effort, an acute shortage of trained personnel, and the perceived gulf between scientific developments and the launching of a product on the market. Overcoming these obstacles will require participation in decision-making by experts from other fields as well as science, and national co- ordination of effort coupled with identifiable, committed funding from government and the private sector. Producer groups and professional societies such as the New Zealand Society of Animal Production should play a leading role in these developments. }, issn = {1176-5283}, author = {Cruickshank GJ and Smith JF and Konlechner J and Parr J} } @conference {40222, title = {Studies on the physiological basis of appetite depression in nematode infection in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {249-254}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The influence of preweaning growth rate on postweaning growth and carcass grading characteristics was investigated in two experiments with lambs at pasture. Differences in preweaning growth rate due to within mob variation, feed allowance treatments or rearing rank had small or no effects on postweaning growth when lambs were offered the same pasture allowance per unit of liveweight or per head after weaning. Therefore lambs with slower preweaning growth rates had lighter carcasses at a common age (P<0.01) or were older at a common weight (P<0.05). Carcass GR measurements were not significantly influenced by preweaning growth rates when compared at the same carcass weight and slaughter date. An increase in weight-adjusted GR measurements was observed over autumn. }, issn = {1176-5283}, author = {Dynes RA and Ankersmit AEL and Poppi DP and Barrell GK and Sykes AR} } @conference {40205, title = {Understanding and exploiting the physiology and endocrinology of reproduction to enhance reproductive efficiency in cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {109-122}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The FSH:LH bioactivity ratios, determined by radioreceptor assays, of four commercial gonadotrophin preparations were Folligon 5; F.S.H.-P. 18; Folltropin 49 and Ovagen 1090. The mean number of oocytes produced in immature rats after ovulation induction following administration of these gonadotrophin preparations by injection (Folligon, 10 to 50 i.u.) or 48h continuous infusion (others, 30 to 1000 ug/day) was dose-dependent, except at the highest doses when mean oocyte numbers either remained unchanged, or fell significantly in the cases of Folligon and F.S.H.-P. The highest mean number of oocytes produced in response to Folltropin (48+9) and Ovagen (47+7) were significantly higher (P<0.05) than those attained with Folligon (21+6) or F.S.H.-P (31+5). Mean ovarian weights also increased in a dose-dependent fashion in response to each of the gonadotrophin preparations. Co-infusion of NIADDK-ovine LH-25 at 10 to 20 ug/day with Ovagen (250 ug/day) or NIADDK-ovine FSH-17 (10 ug/day) (both low in LH activity) increased mean oocyte production 1.5 to 3-fold. Co-infusion of ovine LH at 40 ug/day significantly reduced mean oocyte numbers. }, issn = {1176-5283}, author = {Thatcher WW and Hansen PJ and Plante C and Badinga L and Van Cleeff J and Danet-Desnoyers G and Savio JD and Mirando MA and Bazer FW} } @conference {40270, title = {Use of high fleece weight Romney rams for out-of-season lambing}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {487-488}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The export of live sheep by sea to the Middle East is an area of public concern due, in part, to the high death rates on some voyages, and to the perceptions of poor animal welfare during transport. This paper review the history of sea transport of sheep, the practice, investigations, welfare guidelines, and management progress in the New Zealand live sheep trade. A recent study of sheep exported to the Middle East has identified important behavioural indicators of stress and welfare. The results of this study have led to the implementation of new management systems to meet the identified behavioural characteristics and requirements of British breed sheep. Voyage mortalities consistently less than 1\% in sheep transported from NZ to the Middle East can be expected. }, issn = {1176-5283}, author = {Reid TC and Monigatti AC} } @conference {40263, title = {The use of the somatic cell count of composite milk samples to predict the infection status of the udder in cows from New Zealand dairy herds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {467-468}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied }, issn = {1176-5283}, author = {Holdaway RJ and Holmes CW and Steffert IJ} } @conference {40243, title = {What the market will need from milk production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {375-380}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {DNA profiles, or fingerprints as they are often called, provide the basis for a powerful parentage test that has a number of applications for the animal breeding industry. Two examples of its use are presented here. During a breeding program where single sires were being mated to groups of ewes, two groups became mixed, compromising the experiment. Using DNA profiling results, each of the progeny could be assigned to one of the two rams. The second example involves the auditing of pedigrees which the Booroola gene is segregating. In searching for a DNA marker that segregates with the Booroola gene it is essential that flock records are accurate. In one pedigree a number of individuals that were wrongly assigned as daughters of a heterozygous Booroola sire were identified. In another pedigree all daughters were correctly assigned. }, issn = {1176-5283}, author = {Fenwick RM and Kirkpatrick KJ} } @conference {40233, title = {Wool production and other characteristics of progeny from high performance Coopworths x Romney rams}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {305-310}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Masked by the short-term influences of under or over-production at national level, concerns about the quality and hygiene of animal products and fears regarding dietary influences on human health, long- term projections of what will be expected of the pastoral animal industries are difficult to make. Concerns about the welfare of animals in intensive systems coupled with the political changes taking place in Russia and Eastern Europe are likely to swing animal production more towards pastoral systems. The removal of large quantities of fat from the food chain is likely to become a permanent feature. So too is the trend for a more even flow of high-quality products on to the market. In meeting these goals the role of the current biotechnological revolution, both directly in primary animal production, and indirectly through its contribution to the animal-product and food-processing industries, will be essential. We can not afford intellectual scientific complacency in a world where famine could, however remotely, become a truly global phenomenon. It is against this background that those aspects of the pastoral animal industries that currently limit production are viewed and the opportunities for implementing new technologies outlined. }, issn = {1176-5283}, author = {Andrews RN and Dodds KG and McEwan JC and Wuliji T} } @conference {40185, title = {An alternative hogget-two tooth shearing policy for summer-dry regions in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {291-296}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied }, issn = {1176-5283}, author = {Parker WJ} } @conference {40162, title = {Artificial insemination of farmed feral goats with frozen-thawed semen}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {171-174}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A trial was conducted over 2 years in which the comparative wool growth rates of wethers and dry, single and twin-rearing ewes were measured. The sheep were pasture fed according to 3 regimes of either continuous maintenance or alternating 3-monthly periods of either high or low plane and maintenance feeding. At any one time, groups of sheep were either gaining, maintaining or losing live weight. This paper reports preliminary analyses of the effects on wool growth of year, breed, sheep age and rearing status. Coopworths were consistently heavier than Romneys. As a result of practical constraints associated with the trial design, ewes which reared twins were lighter at the end of the trial than ewes which reared singles which were lighter than wethers and ewes which did not raise any lambs. Romneys grew more wool than Coopworths with no difference in wool production between wethers and ewes which did not rear a lamb. Overall, the clean wool growth rate of the dry sheep was a minimum of 7.2 g/d in July/August and a maximum of 12.5 g/d in November/December. Wool growth rates of the single and twin rearing ewes relative to the dry sheep (100) were 63 and 55 in July/August and 90 and 82 in November/December respectively. Wool growth rates after weaning did not differ between rearing status groups. The combined effect of these differential wool growth patterns on clean fleece weight of single and twin rearing ewes relative to the dry sheep (100) were 86 and 77 in December and 99 and 97 in May respectively. Despite the apparent large reduction in wool production associated with rearing lambs it is still economic at present prices for most farmers to run breeding ewes rather than dry sheep of the same breed.}, issn = {1176-5283}, author = {Moore RW and Dow BW and Staples LD} } @conference {40131, title = {Biological efficiency for venison production in red deer}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {5-10}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {To study the influence of melatonin on seasonal changes in wool production of crossbred sheep, a pharmacological dose of sustained release melatonin was administered over a month in early summer to both fleeceweight-selected and control rams from the Massey university Progeny Test lines. Wool growth and testis diameter were compared with those of untreated animals during the period of melatonin treatment and for a further 2 month period. Melatonin treatment did not significantly change either greasy or clean fleeceweight production. However, the testis diameter of the melatonin- treated animals was significantly greater than in untreated animals during the period of melatonin treatment and significantly smaller during the recovery period. Hence, although the melatonin treatment was sufficient to produce a change in reproductive characteristics, it was not sufficient to induce a measurable change in the pattern of wool production.}, issn = {1176-5283}, author = {Fennessy PF and Thompson JM} } @conference {40180, title = {Breeding season of Romney and Poll Dorset ewes at different locations and the reproductive penalties of a June joining}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {265-270}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The age at which permanent incisor teeth came into wear was recorded in 23 yearling flocks that differed in breed and management, and one mixed-age flock, of spring-born sheep. In female yearling flocks the first pair of incisors came into wear at a median age of 15 months, with a normal range of 13 to 17 months. Variation within flocks was seven times greater than between flocks. Teeth erupted 21 days earlier in male lambs than in half sib sisters. Time of eruption was not affected by lamb breed, date of birth or growth path. Data from the yearling flocks identified a substantial pool of animals older than 12 months of age that did not have two incisors in wear. These animals could be given dispensation for grading as lamb after the normal cut-off date if incisor teeth in wear is accepted as the cut-off criterion. This would help overcome the shortfall in supply of lean, heavy carcasses that occurs each spring before new season{\textquoteright}s lambs reach suitable size. In the mixed age female flock, the median ages when 2, 4, 6 and 8 incisors came into wear were 15, 23, 30 and 42 months. Later pairs of incisors came into wear earlier than commonly assumed and individuals with the same number of incisors varied in age by up to two years. These findings highlight substantial limitations to the use of number of incisors for determining age in sheep.}, issn = {1176-5283}, author = {Knight TW and Kannegieter SG and Hamilton GJ} } @conference {40157, title = {Carcass composition of New Zealand Saanen goats}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {147-152}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Resistance and the {\textquoteright}self-cure{\textquoteright} phenomenon were examined in Coopworth lambs and Saanen kids when they were between 6 and 8 months old. The animals had been reared on pasture from birth until February 1987 at which time they were treated with anthelmintic and withheld from pasture for two weeks. They were given Trichostrongylus colubriformis (500 infective (L3) larvae kg-1) weeks after the initial dose. Faecal egg counts estimated at weekly intervals were significantly higher in kids than in lambs throughout the experiment. Furthermore, a strong acquired resistance was effected in the lambs subsequent to and as a result of the second dosing. The kids failed to show a similar response. Worm counts estimated at necropsy confirmed that spontaneous rejection, against Trichostrongylus and Ostertagia had been produced only in the lambs. These results how clearly that there are some significant differences between grazing lambs and kids in their ability to acquire and sustain a resistance to nematode parasites.}, issn = {1176-5283}, author = {Colomer-Rocher F and Kirton AH} } @conference {40152, title = {Changing the body composition of sheep by feeding}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {121-126}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Effects of autumn-winter feeding level on live weight and the timing and success of hogget mating were studied in 180 cashmere doe hoggets bred from ferals in each of 2 years. They were fed pasture allowances of 0.8 (L nutrition) or 3 kg DM/hd/d (H nutrition) from 10 March to 30 June in 1986 and from 1 May to 10 July in 1987. Start live weights were 13 and 13.3 kg in 1986 and 1987, respectively. In both year H and L hoggets entered a period of weight stasis. H and L group live weight increased to 15.2 and 13.9 kg respectively by 2 May 1986 and then remained almost static. In 1987 H live weight increased to 14.8 kg by 29 May before stasis. L live weights declined slightly. Entire bucks were joined from 1 May to 12 June each year. Teasers were present outside of these times. Peak incidence of puberty occurred between 14 and 29 May in both years and for both H and L treatments. More H hoggets showed oestrus than L hoggets (74 v 37\% in 1986 and 62 v 42\% in 1987). This reflected in a greater percent of H hoggets diagnosed as pregnant when scanned ultrasonically in July (HP/HJ) of 45\% v 18\% in 1986 and 50\% v 34\% in 1987. High nutrition appeared to improve hogget puberty rate over and above its effect on live weight in 1986 but not in 1987. Low levels of cashmere down production were recorded (57 g) and these were not influenced by differences in nutrition.}, issn = {1176-5283}, author = {Cropper MR} } @conference {40146, title = {CIDR-B for managed reproduction in beef cows and heifers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {85-90}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {There is a long-standing disagreement about the influence that feeding has on body composition, particularly in ruminants, yet the problem remains of finding ways to produce lean lambs. This paper attempts to revive the view that feeding can alter, independently, the rate of growth and the relative rate of fattening in sheep. A numerical illustration is given of the relationship between a lamb{\textquoteright}s potential for growth, its feed requirements and the rules it uses to partition feed resources when they are scarce. For simplicity, the feed is considered only in terms of its metabolisable energy; digestible crude protein ratio. Published data are then review to test whether it is reasonable to retain the proposed theory. The review closes with a discussion of our current options and future possibilities for changing body composition by feeding.}, issn = {1176-5283}, author = {McMillan WH and Macmillan KL} } @conference {40133, title = {Comparative effects of dietary molybdenum concentration on distribution of copper in plasma in sheep and red deer (Cervus elaphus)}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {15-20}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Implants of melatonin can improve reproductive performance in sheep but timing of joining is important. In this study, 531 Coopworth ewes were used in a 2x4 factorial design to investigate the effects on reproductive performance of Regulin (melatonin) implants and time of joining. Implanted ewes were treated about 1 month prior to joining on either 1 December, 15 December, 29 December or 12 January. Control ewes were untreated. Matings with Poll Dorset rams were recorded fortnightly until the rams were removed on 5 February. About 10\% of the implanted and control ewes joined on 1 December mated by 29 December. By the end of joining, over 90\% of these early joined ewes had mated. Melatonin treatment had no effect on mating pattern in these 2 joining groups. By contrast, melatonin treatment improved the total number of ewes mated when joined on 29 December (100\% v 58\% P<0.001). About 50\% of the treated and control ewes joined on 12 January had mated by the end of joining, but not melatonin treatment affected return to service rates. Melatonin treatment reduced the pregnancy rate in ewes joining on 1 December and 15 December (69\% v 83\% P<0.01). In contrast, melatonin treatment increased the pregnancy rate for 29 December joinings (72\% v 41\% P<0.001) but not 12 January joinings (49\% v 46\%). The incidence of multiple pregnancies was increased by melatonin treatment (40\% v 30\% P<0.05). The melatonin treatment trend was for fewer lambs per ewe joined for early joining times to more lambs per ewe joined for later joining times. These results demonstrate that reproduction responses to melatonin implants are very sensitive to time of joining. With a late December to mid January joining time and an early February end of joining, between 20 and 40 more lambs per ewe joined was achieved in this study. The onset to the breeding season in these Coopworth ewes is about 2 months earlier than expected. The use of Poll Dorset rams may be an important factor in this early onset.}, issn = {1176-5283}, author = {Osman NHI and Sykes AR} } @conference {40141, title = {Construction of a bovine gene map}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {53-56}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A single intramuscular injection of 10g of Buserelin (Bus), a potent analogue of gonadotrophin releasing hormone (GnRH) was administered to non-lactating Holstein cows (Experiment 1) or Brangus cross animals (Experiment 2) on cycle day 12 (oestrus + cycle day 0). This treatment altered normal patterns of ovarian follicle development, causing atresia or premature luteinisation especially in follicles of 6 to 9 mm diameter. Injecting 8 or 10g Bus every third day from cycle day 12 to cycle day 48 (Experiment 3), extended the average inter-oestrous interval to 56.2 days, maintained diaoestrous concentrations of plasma progesterone (5 to 12 ng/ml), and increased corpus luteum lifespan to at least 49 days in 5 of 6 Holstein cows. This 3 day interval was also used with 18 cows and heifers which were embryo recipients when they had been in oestrus from 2.5 to 7.5 days before their contemporary embryo donors (Experiment 4). The average pregnancy rate following these asynchronous transfers was 38.9\%, varying from 20\% when morulas were transferred to 62.5\% with blastocysts. Inserting a CIDR-B into heifers 12h after the onset of oestrus for 3 to 15 days produced alterations in inter-oestrus intervals which indicated that progesterone treatment during metoestrus could potentiate the capacity of the uterus to synthesise and release prostaglandin F2a (Experiment5). The results from these five experiments showed that manipulating ovarian follicle development with Bus, or altering normal follicle-uterine interactions could be utilised as forms of oestrous cycle control which may be applied after insemination or embryo transfer.}, issn = {1176-5283}, author = {Hetzel DJS} } @conference {40144, title = {Control of the oestrous cycle in farm animals: A review}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {71-80}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The pregnancy status of over 4700 ewes, divided into 21 flocks (137 to 688 ewes) and grazed on 14 properties in the Hawkes Bay, were diagnosed using either or both real time ultrasonic body scanner (ultrasonic) and video-fluoroscopy (X-ray) systems. The diagnosis was checked with the number of lambs born, dead or alive, to each ewe. For the ultrasonic system the percent of ewes whose lambing status was correctly predicted ranged from 96.1 to 100\% for 19 flocks examined. In the case of the X-ray system the values for 13 flocks examined, except for one property, ranged from 94.3 to 99.6\%. The operators must have a special aptitude in handling the instruments and interpreting an image on a screen if good results are to be obtained. The maximal throughputs for the ultrasonic and X-ray systems were 200 and 250 ewes per hour respectively. The major differences between the two systems (ultrasonic v X-rays) were: i) The capital outlay for the ultrasonic system was about a twelfth of that of the mobile X-ray system. ii) A good backup service is needed to maintain the X-ray equipment. iii) To sustain a throughput of over 200 ewes per hour, excluding the operator, 5 labour units were required for the sheep handling associated with the ultrasonic system compared to one for the X-ray system.}, issn = {1176-5283}, author = {Swanson LV} } @conference {40168, title = {Correlated responses in a weight-selection experiment with beef cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {203-208}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Two experiments investigated the post-weaning nutritional requirements and subsequent growth rates of lambs born in May and June. The objective was to produce heavyweight lamb carcasses during the period of otherwise difficult supply (November to January). Experiment 1 examined the feed intake, growth rate and carcass composition of ram and ewe lambs born in late May (weaned late July) offered three pasture allowances. Pasture dry matter allowances of 6\%, 12\% and 22\% of liveweight/head/day resulted in average growth rates of 68, 1109 and 148 g/d, respectively in weaned lambs over the period from July to January. Experiment 2 investigated growth rates of June born lambs fed pelleted supplements (420 g DM/head/day) at pasture. Weaned ram lambs were offered either high protein, medium protein or no supplements at two pasture allowances (12\% and 22\% of live weight/head/day) for 12 weeks between September and December. At the low pasture allowance the high protein supplement gave a 13\% improvement in growth rate (P<0.05) over the medium protein supplement. For the final six weeks of the experiment, half of the high pasture allowance group was offered a white clover dominant pasture. Over this latter period the "clover" group had significantly higher growth rates (233 g/d) than lambs offered either high protein (204 g/d) or medium protein (184 g/d) or no supplements (161 g/d) at high pasture allowances. Carcass weights at slaughter (11th December) were 19.6, 18.6, 18.2 and 16.5 kg, respectively, for these four groups. High protein supplements at pasture increased lamb growth rates, particularly at a low pasture allowance. This would be useful during times of poor or unseasonal pasture production to ensure supply contracts are met, particularly for early, heavyweight lambs.}, issn = {1176-5283}, author = {Morris CA and Baker RL and Hunter JC} } @conference {40142, title = {Development of cattle of superior genotypes: Novel approaches to increasing tolerance of dairy cows to extended milking intervals}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {57-64}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Active immunisation of Romney ewes with bovine follicular fluid (bFF) at monthly intervals for 4 months in the breeding season increased monthly mean ovulation rates by 8 to 100\%, relative to non-immunised ewes, by increasing the frequency of double ovulations. The increases in ovulation rate were independent of the dose of bFF (from 1 to 10 ml) and whether an aqueous- or oil-based adjuvant was used. Immunisation with porcine FF (1 or 5 ml) did not increase ovulation rates significantly. Active immunisation with an androstenedioned-based immunogen (Androvax), increased the mean monthly ovulation rates 31 to 63\% by increasing the frequency of double and triple ovulations. Immunisation with bFF and Androvax together did not increase ovulation rates any more than immunisation with Androvax alone. These results show that active immunisation with bFF can increase ovulation rates in sheep, though generally less effectively than by immunisation with an androstenedione-based immunogen.}, issn = {1176-5283}, author = {L{\textquoteright}Huillier PJ and Davis SR and Carruthers VR and Morris CA and Bryant AM} } @conference {40143, title = {Development of cattle with a modified genotype: Embryological techniques needed for the efficient production of transgenics}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {65-70}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The manipulation of ovulation rate in the red deer hind was investigated by administration of steroid-free bovine follicular fluid (bFF). Twenty-four adult hinds, treated with intravaginal progesterone (CIDR), received a daily intramuscular injection of either 0, 4, 7.5 or 11 mls of dextra-charcoal treated bFF (n = 6 per group) on days -1, 0 and +1 from the time of CIDR withdrawal. After CIDR removal, plasma progesterone concentrations declined in all animals. In control hinds, oestrus occurred 2-3 days later and mean plasma progesterone concentrations began to increase thereafter. In bFF-treated hinds, oestrus was delayed by 3-5 days, and plasma progesterone concentrations remained low for at least 7 days after CIDR withdrawal. Plasma LH concentrations were 2-3 fold higher in the bFF- treated groups, relative to the control hinds, for at least 6 days after the end of bFF treatment. Twin ovulations were recorded in 1/6 control and 5/17 treated animals. At pregnancy diagnosis, 10/23 hinds were pregnant having conceived at the treated oestrus (3/6 control and 7/18 treated), but none had more than one foetus. There was no evidence of a dose-response to bFF treatment. These results indicate that in the hind, bFF can be used to manipulate the timing of oestrus and ovulation rate. A component(s) of bFF may thus have the potential to regulate fecundity in deer.}, issn = {1176-5283}, author = {Thompson JGE and Peterson AJ and Tervit HR} } @conference {40139, title = {Do melatonin implants influence the breeding season in Coopworth ewes?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {43-46}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Although the Booroola F gene increases litter size in the ewes by one lamb there have been no unequivocal reports of its expression in the ram. In this report the presence of the F gene in the ram has been shown to increase sperm swimming speed and a sperm activity index as measured by a dual and single beam laser respectively. The lambing rate of ewes artificially inseminated with sperm from rams with the FF genotype was slightly higher than those inseminated with sperm from rams without the F gene.}, issn = {1176-5283}, author = {McMillan WH and Sealey RC} } @conference {40175, title = {Early lambing in Hawkes Bay: The effect of pasture allowance and protein supplementation at pasture on lamb growth rates}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {237-244}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Groups of Coopworth ewes were mated to Polled Dorset rams at 2 monthly intervals for 12 months following induced ovulation and synchronised oestrus. The ram lambs were made cryptorchid and grown to a target slaughter liveweight of 40 kg. The influence of birthdate on birthweight, pre- and post-weaning growth rate, time from birth to slaughter and carcass leanness was studied. The major influence on lamb performance was the timing of lambing in relation to spring pasture growth and the subsequent summer period, characterised by low pasture growth and quality. When late gestation was during summer lamb birth weight was lower (3.5 and 3.6 kg for January and March born lambs respectively) than for other periods (4.3, 4.4, 4.8 and 4.5 kg for May, July, September and November born lambs respectively). Similarly, pre- and post-weaning growth rates were higher during spring (pre-weaning maximum, 276 g/d for lambs born in July; post-weaning maximum 223 g/d for lambs born in May) and lowest during summer (pre-weaning minimum 150 g/d for lambs born in November, post-weaning minimum 123 g/d for lambs born in September). Age at slaughter was lowest for lambs born in May and July and highest for lambs born in September and November. When corrected to an average liveweight of 42 kg the average age was 230, 208, 176, 175, 245 and 236 days for lambs born in January, March, May, July, September and November respectively. These data suggest that lamb growth to these comparatively high slaughter weights was optimal when lambs were born in May and July. If premiums are offered for out-of-season production of heavy carcasses to supply the chilled meat trade, May appears to be the optimal time for lambing as the average slaughter date for this group was 27.10.87, compared to 12.01.88 for lambs born in July.}, issn = {1176-5283}, author = {Muir PD and Wallace GJ and Smith NB and Ryan AM} } @conference {40181, title = {Early lambing in Hawkes Bay: Use of the ram effect}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {271-276}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Three trials involving a total of 345 animals have been conducted in widely separated geographical regions in New Zealand, using a similar trial design to compare different treatment regimes for invermectin in beef weaners. Commencing at weaning and continuing into late winter/spring, trial animals received ivermectin subcutaneously at 200 }, issn = {1176-5283}, author = {Muir PD and Smith NB and Wallace GJ} } @conference {40148, title = {Effect of active immunisation with follicular fluid on ovulation rates in Romney ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {97-102}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Twenty four beef carcasses, all visually graded as P1, were assigned on the basis of fat depth D, to fat classes L (n=5), P (n=7), K (n=8) and G (n=4). The percent dissected lean of these samples for each class was: L, 66.9; P, 64.6; K, 63.4; G, 60.7, while total dissected fat \% was: L, 14.5; P, 17.3; K, 19.0 and G, 21.8. There were no significant differences in chemical composition of individual joints across fat classes, but there were highly significant differences between joints. Percent intramuscular fat content of the lean was: topside, 5.0; chuck, 7.5; loin, 12.1 and brisket, 12.4. Overall acceptability of the cooked loin was similar for all fat classes, despite a range from 4 to 24\% in intramuscular fat content. There was not significant association between intramuscular fat and eating quality, which suggests that if pre- and post-slaughter conditions are well controlled, meat of satisfactory eating quality can be obtained from lean carcasses.}, issn = {1176-5283}, author = {Henderson KM and Ellen RL and Weaver A and Ball K and McNatty KP} } @conference {40188, title = {Effect of different ivermectin treatments on weight gains in beef weaners}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {307-313}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Detailed sward measurements made before and after grazing can detect the changes in mass and composition of vertical sward horizons which result from grazing. When animal species are grazed in mixtures, it is impossible, by this method to relate such sward changes to any one particular species. We estimated that quantitative importance of different sward horizons to the diet of cattle (CA), sheep (SA) and goats (GA) grazing alone or in a mixture; cattle with sheep (CS), sheep with cattle (SC) and cattle with goats (CG), goats with cattle (GC) in a progressive defoliation of ryegrass/white clover pasture. A least squares optimisation routine estimated the contribution of 5, 40mm sward horizons, each containing 6 botanical components to oesphageal extrusa (OE), containing the same 6 components, from each of the treatments. The results suggest that the diet of CA was more equally derived from horizons above 40mm than was that of SA which was concentrated in the 80- 120mm horizon. GA was intermediate. The contribution of the upper sward horizons to the CS diet was greater than for CA and SC moved lower down the sward horizons than SA. The mixing of goats and cattle had less effect on the relative contribution of the sward horizons to the diet selected than mixing sheep and cattle. }, issn = {1176-5283}, author = {McPherson WB and Cairns GC and Leaning WHD and Newcomb KM} } @conference {40137, title = {The effect of exogenous melatonin, administered in summer, on wool growth and testis diameter of Romneys}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {35-38}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The expansion of molecular biology across most biological fields has meant an increasing application of this technology to agriculture. One of the most exciting new areas to emerge has been that of transgenic animal production. Genes, from a variety of sources, can be incorporated into the early embryo and therefore effectively alter the genotype, and even the physiology of an animal. Most of the work has been conducted using the laboratory mouse. Translation of the technology to the domestic animal has not met with great success, partly because of the genes and promoters chosen and partly because of the difficulty and expense in obtaining large numbers of suitable early embryos for gene incorporation. An efficient gene incorporation system is cow embryos ideally requires the development of a number of novel embryological techniques. They include in vitro maturation and fertilisation of bovine oocytes from abattoir- sourced ovaries, in-vitro culture to allow the development of fertilised embryos to readily transferable stages, satisfactory techniques for incorporating genes into the embryo and techniques such as embryonic cloning to exploit the transgenic cattle produced. The various techniques, their problems and successes are described in depth in this paper. A research programme has been initiated to link embryology, dairy science and molecular biology techniques with the aim of producing transgenic cattle with modified milk composition.}, issn = {1176-5283}, author = {Harris PM and Xu ZZ and Blair HT and Dellow DW and McCutcheon SN and Cockrem J} } @conference {40161, title = {The effect of integrated grazing of goats, sheep and cattle on animal productivity and health on high-producing hill country pastures}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {165-170}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A selection experiment at Waikite (Rotorua) began in 1971 with closed Angus herds selected for adjusted 13-month weight (AS1), adjusted 18-month weight (AS2) or with random replacement (ACO). A closed Hereford herd, selected for adjusted 13-month eight (HS1), was also established. At both 13 and 18 months of age, annual responses in live weight in the AS1, HS1 and AS2 herds averaged 0.96, 0.62 and 0.48\% of the ACO herd means (calvings 1972-85). Five correlated responses were estimated. 1. Cow weight: From all ages of cows recorded over 4 seasons (on average 11 years of selection completed), AS1 and AS2 cows were 7.5 and 8.2\% heavier respectively than ACO cows; HS1 cows were 2.5\% heavier than AS1 cows, the same margin as in 1971. 2. Maternal weaning weight: (AS1 and AS2 herds only, relative to ACO): responses was estimated in a tester herd from calvings in 1982-86. The maternal grandsires were selected AS1 and AS2 bulls born after almost 2 generations (6 years) of selection. The AS1 herd was superior by 8.6 kg (5.7\%) and the AS2 herd by 2.2 kg (1.5\%). 3. Scrotal circumference: From the 1982-85 crops, the AS1 and AS2 bulls had respectively 0.9 (P<0.01) and 0.3 cm larger circumferences at 13 months of age and 0.7 (P<0.01) and 0.4 cm below corresponding AS1 values. 4. Height at withers: AS1 and AS2 bulls from the 1981 calf crop were respectively 3.5 and 2.5 cm taller (P<0.05) than the ACO bulls; the HS1 bulls were 2.3 cm taller (P<0.05) than the AS1 bulls. 5. Food intake: Average intake of silage by Angus bulls from the 1980 and 1981 crops were 10.4\% and 11.7\% greater (P<0.01) for AS1 and AS2 than ACO cattle respectively. Expressed relative to body weight, there was no significant difference due to herd. The pooled regression of daily intake of dry matter on 18-month weight was 0.0091 kg/kg (P<0.05), with a correlation of 0.32. The correlations of pre-fasting plasma tryptophan and the fall in plasma tryptophan concentration with average previous intake were 0.50 and 0.41, for bulls fasted over a 48 h period.}, issn = {1176-5283}, author = {Bown MD and McCall DG and Scott ML and Watson TG and Dow BW} } @conference {40153, title = {Effect of liveweight gain or loss on lamb meat quality}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {127-132}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied}, issn = {1176-5283}, author = {Kirton AH and Thorrold BS and Mercer GJK} } @conference {40136, title = {Effect of melatonin immunisation on liveweight gain of red deer}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {29-34}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The primary constraint to extended milking intervals of dairy cattle without loss of solids production is the storage capacity of the udder needed to accommodate the milk produced over the extended period. This constraint may be overcome by the production of more concentrated milk as the volume of production is a major determinant of udder capacity. The production of more concentrated milk is being explored by two approaches. The first exploits the natural variation in milk solids{\textquoteright} concentration present in commercial dairy herds. The herd test records from LIC, NZDB were used to identify 2 groups of 19 high breeding index Jersey cows with either high or low milk solids content, which were subsequently established at Ruakura in June 1988 along with 19 high BI Friesians. Mean fat concentration in November 1988 was 6.61, 5.32, and 4.74 for high and low solids and Friesian groups respectively. Corresponding values for protein content were 4.34, 3.72 and 3.42\%. Effective hours worth of udder capacity in October-November 1988 was 27.4, 24.8 and 22.9 hours for high solids, low solids and Friesian groups respectively. The second approach involves the use of recombinant DNA techniques to modify the expression of the a-lactalbumin gene, a key component in water secretion in milk. Alpha-lactalbumin, one of the major whey proteins and a component of the enzyme lactose synthetase, plays a major role in regulation and synthesis of lactose, which in turn is the major osmole of milk. Antisense RNA and RNA enzymes can be used for highly specific inhibition of gene expression. These gene blocking agents bind to the {\textquoteright}natural{\textquoteright} mRNA and block translation of the message into a protein. An antisense RNA construct with RNA enzyme cleavage activity against the a-lactalbumin gene has been constructed and is currently under evaluation. This construct will be placed downstream to a mammary specific promoter region and inserted into the bovine genome by gene transfer techniques to produce a transgenic animal. These techniques have considerable potential as tools in physiological studies and for producing animals of superior genotypes.}, issn = {1176-5283}, author = {Duckworth JA and Barrell GK} } @conference {40155, title = {The effect of pH on colour and drip loss of lamb chops thawed in air and CO2}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {137-142}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Kidding and multiple kidding rates following artificial insemination (AI) either at the second oestrus after CIDR withdrawal or after vasectomised buck introduction to isolated does were compared in a factorial design. Other factors were a comparison of cervical and laparoscopic AI; Regulin melatonin implants 4 weeks before AI versus no implants; and once daily oestrus detection with AI 2-5 hours after detection versus twice daily oestrus detection with AI 9-18 hours after detection. AI was carried out from 6-14 April, 20-28 days after CIDR withdrawal or 6-14 days after buck introduction. Laparoscopic AI resulted in a high kidding rate (65\%) than cervical AI (34\%). Regulin implants resulted in a lower kidding rate (38\%) than no implants (47\%) but a higher multiple kidding rate (68\% versus 50\%). There was no effect of once versus twice daily oestrus detection on kidding rate. CIDR treatment led to a higher proportion of the does present being inseminated (98\%) than buck introduction (88\%) during the 9 day AI period, but had no effect on overall fecundity.}, issn = {1176-5283}, author = {Moore VJ} } @conference {40138, title = {Effect of Regulin implants on spring fertility, lactation and down growth of cashmere does}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {39-42}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Ultrasonography has permitted close visualisation of follicular development in cattle and has revealed that three waves of follicles normally develop during the oestrous cycle. Follicle stimulating hormone is important for the recruitment of follicles but it is not known how the recruited follicles are selected to become dominant over other follicles and eventually to ovulate. Hypothalamic, pituitary and ovarian hormones are secreted and released episodically. During the luteal phase of the oestrous cycle, the negative feedback of progesterone prevents any rise in luteinising hormone (LH). As progesterone levels fall, LH increases, prompting an increase in oestradiol which triggers the ovulatory LH surge and behavioural oestrus. LH causes ovulation and luteinisation of follicular cells. Luteal phase progesterone may be responsible for later increases in prostaglandin F2a (PG)F2a, a luteolytic hormone in cattle and sheep which is transferred from the uterus, its site of synthesis, to the corpus luteum. Oestradiol and oxytocin, synthesised in the ovary, may be involved in regulation of uterine synthesis of PGF2a, hastening luteolysis. At this time it is not known how essential these two hormones are to the process of luteolysis. The discovery and synthesis of new ovarian hormones should permit superovulation to become a more exact and a less expensive procedure and for embryonic mortality to be reduced.}, issn = {1176-5283}, author = {Moore RW and Bigham ML and Staples LD} } @conference {40176, title = {Effect of spraying pasture with fungicide on growth rates of grazing lambs in autumn and spring}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {245-248}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The hogget reproduction of 67 FF/F+ and 27 ++ (Booroola x Romney) x (Booroola x Perendale), 30 Waihora (WR) and 39 Marshall Romney (MR) hoggets was compared under 4 nutritional treatments. The September born ewe lambs were grazed from 6 January to 5 June at 4 different pasture allowances: 2, 4, 6, and 10 kg DM/ewe/d. Three allowances (2, 4, 10) were continued until 11 September, following this date all ewes grazed together. There were significant effects of allowance on the percentage of ewes tupped and pregnant. There was no effect of genotype on these fertility traits. The percentages of ewes lambing multiples/ewes lambing were FF/F+ 58, ++ 0, MR11, and WR 27. The percentages of lambs weaned/lambs born were similar: 72, 59, 77 and 79 respectively. The percentages of lambs weaned/ewes joined were 58, 26, 26, and 49 respectively.}, issn = {1176-5283}, author = {Reid TC and Lauren DR} } @conference {40145, title = {The effect of the F gene on characteristics of Booroola x Romney ram sperm}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {81-84}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Real-time (B-mode) and simple (A-mode) ultrasonic instruments were evaluated in 2 experiments to assess their potential for measuring carcass fat and muscle variables. In a third experiment, progeny of five Romney selection lines were ultrasonically scanned at regular intervals from 5 to 14 months of age to record backfat thickness (C), GR and the width (A) and depth (B) of the L. dorsi muscle. In the one calibration experiment where the Toshiba machine was used, the machine was found to be particularly appropriate for measuring GR depth achieving a weight adjusted partial correlation of 0.81 with the carcass measurement and repeatability of 0.86. Comparable figures for the AIDD scanner in two experiments averaged 0.75 and 0.82 respectively for C fat depth measurements. Prediction equations for the chemical carcass lipid content showed that including either C or GR ultrasonic fat depths provided significantly improved estimates over those using only live weight. The addition of ultrasonic muscle widths or depths provided little additional advantage. The ultrasonic C and GR measurements confirmed that the production index line, selected on an index comprising dam{\textquoteright}s number of lambs born and the animals own weaning and hogget fleece weight, was the leanest. The single trait line selected on dam{\textquoteright}s number of lambs born, was slightly leaner than the controls, while the hogget fleece weight line was similar to the control line. The ranking of the 100 day weight selection line was found to vary with year of birth measured, but on average was similar to the control line. In contrast no major differences were detected in muscle width or depth among any of the selection lines.}, issn = {1176-5283}, author = {Moore RW and Woolhouse JK and Wilson MC} } @conference {40163, title = {Effects of cold conditions on the oxygen consumption of shorn goats}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {175-178}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Visual culling of 16-month old Romney ewe hoggets without access to performance records was carried out by five different groups of farmers who had contributed rams to the Rotomahana Strain Trial. Reasons for culling decisions were recorded and then all ewes, including those {\textquoteright}culled{\textquoteright}, were retained and farmed as a single flock to compare lifetime performance of culled and selected ewe replacements. Each group of farmers put most of its culling emphasis on size (i.e. smaller sheep were culled), with varying culling emphasis on mouth structure, woolly faces and wool. Less than five percent of the culling emphasis was for foot structure or breed type. All groups of farmers were able to {\textquoteright}select{\textquoteright} ewes that had subsequent performance (number of lambs weaning and wool weight produced) superior to their {\textquoteright}culled{\textquoteright} group of ewes. There was about a two-fold range among breeders in the effectiveness of their culling in terms of economic returns for lambs weaned plus wool produced over three lambings. Evaluation of ewe production through to seven years of age showed that the effects of visual culling on subsequently ewe performance were maintained over the lifetime of the ewe. The effect of {\textquoteright}culling{\textquoteright} using performance traits in the same ewe hoggets as were subjected to visual culling was also assessed. Culling on most performance traits in the same ewe hoggets as were subjected to visual culling was also assessed. Culling on most performance traits was more effective than visual culling, resulting in up to 50\% greater economic returns. Post-weaning body weights or fleece weights or a combination of these traits, were the most useful objective culling criteria.}, issn = {1176-5283}, author = {Holmes CW and Clark DA} } @conference {40140, title = {Effects of melatonin on body weight, appetite and seasonal fur growth in the ferret}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {47-52}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A controlled internal drug release device, containing progesterone (CIDR-B), was evaluated as an aid to reproductive management in beef cattle in 2 trials. In Trial 1, 223 animals, comprising 64 early calving cows, 61 late calving cows, 59 maiden cows and 39 15-month heifers (yearling heifers), were treated intravaginally with CIDR-B for either 12d (plus 10mg oestradiol benzoate; 12d CIDR-B + ODB) or for 15d (15d CIDR-B). CIDRs were reused for 5d in half the animals from 16d after initial use. In Trial 2, 145 animals, comprising 53 early calving cows, 43 late calving cows and 49 15 month heifers, were treated intravaginally with CIDR-B for either 14d (14d CIDR-B) or 21d (21d CIDR-B). At CIDR-B withdrawal, half of the animals received an intra-muscular injection of 400IU PMSG. In Trial 1, within 48h of CIDR-B withdrawal, 58\% and 54\% of the animals were mated in the 15d CIDR-B and 12d CIDR-B + ODB groups respectively. Within 96h, the incidence of mating was 87\% and 76\% respectively with the difference between treatments being more pronounced in cows (88\% v 74\%; P<0.05) than in yearling heifers (86\% v 84\%). In cows, pregnancy rate to mating over the first 4 days was 50\% in the 15d CIDR-B group and 67\% in the 12d CIDR-B + ODB group (P<0.05). In yearlings, there was an opposite tendency (71\% v 44\%; P>0.1). Final pregnancy rate was 92\% with no treatment group differences. CIDR-B ruse did not alter conception rates to first or second service but did synchronise returns. In Trial 2, within 4d of CIDR-B removal, 88\% and 97\% of the 14d CIDR-B and 21d CIDR-B groups had mated. In the 0 and 400 IU PMSG groups, 90\% and 95\% had mated. Pregnancy rate in treated animals to mating over the first 4 days following CIDR-B withdrawal were similar in the 14d CIDR-B and 21 CIDR-B groups (54\% v 57\%) and 0. and 400 IU PMSG groups (55\% v 56\%). However, pregnancy rate tended to be lower in yearling heifers compared to cows (46\% v 57\%; P>0.1). Final pregnancy rate tended to be higher in the 21d CIDR-B group than in the 14d CIDR-B group (89\% v 82\%; P>0.1). Fewer heifers were finally pregnant compared to early and late calving cows (74\% v 85\% v 95\%). In both trials, longer CIDR-B treatment intervals were associated with earlier and more synchronised matings. Acceptable pregnancy rates were achieved with CIDR-B treatment intervals of between 12d and 21d. These results indicate that CIDR-B treatment without supplementary hormones can produce acceptable synchrony and fertility in naturally mated suckling beef cows and yearling heifers.}, issn = {1176-5283}, author = {Pearson AJ and Ashby MG and Staples LD} } @conference {40184, title = {Effects of nutrition and shearing during pregnancy on birth weight in highly fecund Booroola-cross sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {285-290}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Current views and recent research findings on the plant characteristics influencing (a) herbage production and tolerance of grazing and (b) herbage intake and nutritive value, are reviewed and used to define desirable plant ideotypes for grazing systems. The conflict of interest between physical and physiological characteristics conferring high production and consumption potential on the one hand, and flexibility of production and grazing tolerance on the other, is emphasised. Current progress in and future prospects for the improvement of plants for grazing systems are discussed briefly, with reference to the potential for using mass selection and genetic engineering techniques in the modification of physical and biochemical characteristics. The need for objectivity in screening and evaluation programmes is discussed. }, issn = {1176-5283}, author = {Orleans-Pobee J and Beatson PR} } @conference {40172, title = {Effects of selection for shear strength on structure and rumen digestion of perennial ryegrass}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {225-228}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Lamb production from May or August lambing by Merino and Comeback ewes was compared from 1982 to 1985 in a factorial design experiment at Hamilton, Western Victoria. Groups of 50 ewes were stocked at 500 kg live weight/ha or 12.4 Merinos/ha and 10.8 Comebacks/ha. Natural fertility levels were similar for all treatments with an average of 5\% ewes not lambing. Comeback ewes had a higher lambing rate (lambs born/ewes joined) at August compared with May lambing (1.28 v 1.19 sed 0.052) whereas the Merinos had similar lambing rates (1.03 v 1.07 sed 0.02), indicating that the Western Victorian Merinos were relatively insensitive to seasonal effects (photoperiod) on fecundity. Lamb mortality was higher at August compared with May lambing (18.5 v 14.5\% sed 1.8\%) and was associated with higher chill factors in August due to cooler, wetter weather. The effects of lamb mortality lead to similar weaning rates (lambs weaned/ewes joined) for Comebacks at May and August lambing and lower weaning rates for Merinos at August compared with May lambing. Lamb weaning weights were similar for both lambing times, except in 1985 when severe internal parasite infections before weaning in groups lambing in May restricted lamb growth. The lower stocking rate (ewes/ha) balanced the higher per head production for Comeback ewes and lead to no significant differences between breeds or lambing times in weight of lamb weaned per ha.}, issn = {1176-5283}, author = {John A and Inoue T and Brookes IM and Hunt WF and Easton HS} } @conference {40171, title = {Effects of selection for shear strength on the voluntary intake and digestion of perennial ryegrass fed to sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {221-224}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Mature Romney ewes were involved in three experiments at Flock House Agricultural Centre and Limestone Downs (near Raglan) to identify factors affecting the percentage of ewes pregnant to mating in November and December following treatment with CIDRs and PMSG. Dorset rams were no better than Romney rams for mating and increasing the ram percentage from 10\% to 15\% failed to overcome the low conception rate of 50-65\%. Rams that had been used for mating 11 days previously increased the percentage of ewes pregnant. Ewes previously lambing in autumn had only a 4.8\% increase in ewes mated and pregnant compared with ewes previously lambing in spring. Despite the reuse of CIDRs reducing the percentage of ewes mated by 6.1\% it was still economical to reuse CIDRs. There was a consistent increase in ewes pregnant and multiple pregnancies with increasing dose of PMSG. By contrast live weight had no effect on the reproductive performance of ewes except for those ewes less than 40 kg live weight. Regulin implants failed to overcome the low conception rate of ewes mating following treatment with CIDRs and PMSG in December.}, issn = {1176-5283}, author = {Inoue T and Brookes IM and Barry TN and John A} } @conference {40132, title = {Efficacy of Coprin in deer and sheep: An evaluation and comparative study}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {11-14}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The effect of treatment with melatonin (Regulin(r)) implants on spring down growth, oestrus and conception rates was examined in dry does (n=84), while the effect of this treatment on down growth, lactation and kid growth rates was examined lactating does (n=109). Treated does were implanted 3 times at 8 weekly intervals starting in early September. The animals were shorn and fleeces sampled on 26 January. Regulin(r) melatonin treatment increased down weight by 43\%, 92\% and 88\% in dry hoggets, dry mixed-age and lactating mixed-age does, respectively, and increased down diameter by 6\%, 2\% and 4\% and total fleece weight by 22\%, 29\% and 30\% respectively. The down weight of the untreated lactating does (12.3g) was half that of the untreated dry does (24.3g). The lactating mixed-age does kidded from 30 August to 29 September, 4 does kidded before the first implant. Regulin(r) treatment had no effect on the appearance of milk secretions or the weaning weight of kids. Fertile bucks were joined from 6 October to 20 October and from 24 November to 8 December to the dry does. There was 1 mating mark and pregnancy in the treated does in the first joining period and no mating marks in either groups in the second period.}, issn = {1176-5283}, author = {Harrison TJ and Sykes AR and Familton AS} } @conference {40165, title = {Estimates of environmental effects and genetic parameters for live weights and fleece traits of Angora goats}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {183-190}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Low voluntary intake and animal performance with perennial ryegrass has been attributed to its high leaf strength. Perennial ryegrass populations were selected for high or low shear strength and individual plants of low (LS) and high (HS) selections grown in a controlled environment. Shear strength of LS leaves (290 g) was half that of HS leaves. LS leaves were shorter, narrower and lighter. However, shear strength of LS remained significantly lower after adjustment for differences in leaf width. Shear strength in both selections declined from leaf base to leaf tip. LS leaves contained less sclerenchyma but had similar vascular tissue content. Sclerenchyma was significantly correlated with shear strength (r=0.82). Chopped leaves (5 cm) from both selections, placed in polyester bags were subjected to rumen microbial digestion. The higher shear strength of HS selected plants was maintained for at least 24 h rumen digestion. It is concluded that lower shear strength was a result of decreased sclerenchyma content and that potential improvements arising from easier breakdown would be maintained during rumen digestion in vivo.}, issn = {1176-5283}, author = {Nicoll GB and Bigham ML and Alderton MJ} } @conference {40160, title = {Fibre growth cycles of unselected, reproducing cashmere does discussed in relation to winter shearing}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {163-164}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Animalplan is an integrated set of data processing packages that meets the pedigree and performance recording requirements of many animal species in a unified way. The package offers much flexibility in terms of specification of breeding objectives, the traits to be recorded and presentation of reports. Technical aspects discussed include breeding objectives, trait adjustment for non-genetic effects using standard or flock/herd specific adjustments, prediction of breeding values using selection index techniques, restricting a trait to zero genetic change and the estimation of direct and maternal effects.}, issn = {1176-5283}, author = {Mitchell RJ and Betteridge K and Welch RAS and Gurnsey MP and Nixon AJ} } @conference {40182, title = {The growth of lambs throughout the year in the Waikato}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {277-280}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied }, issn = {1176-5283}, author = {Cruickshank GJ and Smith JF} } @conference {40149, title = {Induction of twin ovulations in red deer hinds with steroid-free bovine follicular fluid}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {103-106}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Because the enzyme catalase is involved in the peroxisomal pathway of fatty acid oxidation in the liver, it is possible that higher levels of catalase activity may be associated with higher levels of fatness. This was investigated in the high and low backfat Southdown sheep selection lines at Massey University. Liver biopsies were taken from 13 high backfat (HBD) and 14 low backfat (LBD) ewe hoggets with mean liveweight-adjusted ultrasonic backfat depths (LABF, expressed as percentage deviations) of +42\% and -20\% respectively. The HBD group had significantly higher (P<0.05) liver catalase activity (1944 }, issn = {1176-5283}, author = {Fisher MW and Fennessy PF and Henderson KM and Newman RE and Manley TR} } @conference {40174, title = {The influence of sward height on the mechanics of grazing in steers and bulls}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {233-236}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A low cost system for producing early lambs is desirable both to capitalise on Hawkes Bay{\textquoteright}s climatic advantage of a mild winter and to minimise the feed deficit that results from a dry summer. A series of trials was undertaken to develop a system for using the "ram" effect to stimulate early oestrus (December/January) in otherwise anoestrous Romney ewes. When Poll Dorset rams (5\%) and oestrous Poll Dorset ewes (10\%) were joined with Romney ewes in early December, more ewes were mated after 3 cycles than when Poll Dorset rams alone were joined. The effectiveness of social facilitation appeared to vary between years with between 39 and 97\% of Romney ewes mated after 3 cycles to an early December joining. The social facilitation effect also appeared to be less marked at a January joining. Romney ewes with a range of lambing rates from May to September and mean lactation periods of 12 weeks were weaned at varying intervals (12. 6 and 0 weeks) prior to ram introduction in early December. There was no difference in rate of onset of oestrus. Mean lambing dates for 90\% of the ewes in the 3 groups were 18th, 12th and 10th June, respectively. There was no effect of live weight or body condition on date of first oestrus. Romney ewes were exchanged between Hawkes Bay and Wanganui to examine the effect of genotype and environment on the onset of oestrus. Poll Dorset rams (6\%) were introduced on 30th November. By the 27th January 87\% of ewes had been mated at the Hawkes Bay site compared with 15\% at Wanganui. At each location there was little difference between ewes from the two sources in rate of onset of oestrus.}, issn = {1176-5283}, author = {Mursan A and Hughes TP and Nicol AM and Sugiura T} } @conference {40186, title = {Inheritance of loose wool bulk}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {297-302}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The digestive efficiency of deer, goats and sheep fed on chaffed lucerne hay was compared during summer (S) and winter (W). VFI, rumen pool size and rumen ammonia concentration showed seasonal cycles in red deer, with maximum values in S and minimum values in W, whereas rumen FOR showed lower values in S than in W, especially for particulate matter. Despite an increase in VFI, deer were thus able to maintain DM and fibre digestibility in S, due to simultaneously increasing rumen size and reducing outflow rate. Goats showed higher fibre digestibility relative to sheep, associated with a larger proportion of small particles in rumen digesta. Goats also had the highest rate of rumen ammonia production. Relative to goats and sheep, deer showed very low levels of VFI and rumen pool size in W, emphasising the importance of understanding the factors controlling winter inappetence in red deer, whilst the superior fibre digesting capability of goats suggests they could be most efficiently used to utilise low quality fibrous feeds. }, issn = {1176-5283}, author = {Sumner RMW and Clarke JN and Johnson DL} } @conference {40179, title = {Lamb production from Merino-type ewes lambing in May and August in Victoria}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {261-264}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {An assortative breeding programme was carried out in 4 industry Perendale flocks and at Whatawhata using Cheviot, Perendale, Romney and Coopworth sheep. Within the industry flocks rams of high and low loose wool bulk were progeny tested. At Whatawhata Cheviot and Perendale rams of high, medium and low loose wool bulk were mated to ewes of equivalent bulk type within their own breed. High and low loose wool bulk Cheviot and Perendale rams and high loose wool bulk Romney rams were also mated to randomly allocated groups of Romney and Coopworth ewes. Progeny data provided an estimate of the phenotypic correlation between loose wool bulk measured at lamb and hogget shearing of 0.5. Breed effects on hogget loose wool bulk were essentially additive and complementary to the effects of sire selection within breeds. Statistical methods for evaluating heterogeneity of within-family variance of loose wool bulk at hogget shearing were used to investigate the possibility of a major gene influencing loose wool bulk. These methods could not confirm the hypothesis of a major gene controlling loose wool bulk. Offspring-parent relationships were consistent with previously published heritability estimates of around 0.5.}, issn = {1176-5283}, author = {Thompson KF and Obst JM} } @conference {40183, title = {Lambing of Romney and Booroola cross hoggets with and without the F gene under different pasture allowances}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {281-284}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Ruminants grazing pasture rarely approach their genetic potential for meat, milk or wool production. There are wide differences also between plant species and between leaf, stem and inflorescence fractions in their capacity to sustain animal production. The relatively low productivity of grazing ruminants and the differences between plant components in nutritional value can be explained from an understanding of the factors that determine nutrient supply to the animal{\textquoteright}s tissue and the efficiency of metabolism. Nutrient supply to the tissues depends on Ii) the nutrient contents of the forage available, which varies between plant species, their component parts, their stage of maturity and the growing conditions; (ii) the pasture components actually selected by the animal which are influenced by ease of eating, taste, odour and tactile characteristics of the plant material available, its water content, the structure of the sward, the dimensions of the animal{\textquoteright}s incisor arcade and its previous experience; (iii) the amount of each selected component eaten, which is influenced by the potential of the animal to utilize nutrients, the capacity of the reticulo-rumen and factors that affect the rate of digestion and outflow of organic matter from the rumen, and the time spent in eating and ruminating activities; (iv) modifications of consumed nutrients by rumen microbes, particularly the extent of breakdown of plant protein and the relative proportions of volatile fatty acids produced; (v) the efficiency of biochemical reactions metabolising the absorbed nutrients. Although a great deal is known about the way each of these factors influence nutrient supply to grazing animals, the complexity of the interactions between them often makes it extremely difficult to identify the specific reasons for reduced performance in any particular situation. However, by integrating current concepts and knowledge using computer simulation techniques, the factors limiting nutrients supply to the animal{\textquoteright}s tissues can be determined and the value of alternative management strategies for improving animal productivity assessed. }, issn = {1176-5283}, author = {Moore RW and McMillan WH and Dockrill G and Dow BW} } @conference {40156, title = {Liver catalase in Southdown sheep selected for high and low backfat depth}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {143-146}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Four pairs of shorn Cashmere-type goats, fed at 1.5 x maintenance, were exposed to air temperatures between 5}, issn = {1176-5283}, author = {Peterson SW and Purchas RW} } @conference {40173, title = {Magnesium absorption from the large intestine of sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {229-232}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The proportions of ewes ovulating and ovulating multiples were recorded monthly from July-April in Poll Dorset ewes at 2 locations, and in Romney ewes at 4 locations. Flocks of 50-100 ewes were split into two groups and alternated from being isolated to being with vasectomised Dorset rams. Romney ewes differed between locations in ovarian activity even in July (83 and 56\% ovulating in Levin and Ohakune). Romney ewes were anovular by September-October. By contrast, Poll Dorset ewes had a similar trend to ewes ovulating. Poll Dorset ewes at both locations returned to full ovarian activity between late December and January. In Romney ewes there were differences between locations in onset of ovarian activity, with the earliest location being Takapau, and Ohakune the latest. Onset of ovarian activity was 2-3 weeks earlier for teased than for isolated Romney ewes. The response to teasing at the end of the breeding season was small (12-15\%) compared to the beginning of the season (44\%). In a second experiment, 2500 mature Romney ewes were randomly allocated to two groups. One group was joined on 15 April and the other on 10 June. There were no differences in ewes lambing (96 v 97\%) but multiple births declined from 44\% for the early to 18\% for the late joined ewes. This was partially offset by higher lamb survival in the later joined ewes (88 v 79\%).}, issn = {1176-5283}, author = {Dalley DE and Sykes AR} } @conference {40178, title = {Mating Romney ewes in November-December using CIDRs and pregnant mare serum gonadotrophin}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {255-260}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The policy on most New Zealand sheep farms is to pre-tup shear two tooths in late February/early March two to four weeks prior to mating. However, in summer-dry regions, where feed supplies are typically low in late summer, this practice may potentially depress two tooth performance because post-shearing increases in feed requirements cannot be met. An alternative hogget-four tooth shearing arrangement which does away with late summer/autumn two tooth shearing has therefore been investigated at Massey University{\textquoteright}s "Riverside" sheep farm in the Wairarapa; a farm prone to summer droughts. In trials over three years the alternative shearing arrangement was found not to disadvantage ewe liveweight gains, fertility, wool production or financial returns. In addition to reducing autumn feed requirements, earlier objective selection of flock replacements and hogget mating are potential benefits of the alternative shearing programme. A slightly poorer spring cashflow results but otherwise management requirements are similar.}, issn = {1176-5283}, author = {Knight TW and McMillan WH and Kannegieter SG and Sorensen ES and Ridland CJ and Gibb M} } @conference {40158, title = {Meat yields and chemical composition of muscle in New Zealand goats}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {153-156}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Three data sets comprising 2329, 2102, and 720 Angora goats sired by 30, 29 and 17 bucks used in the Land Corporation{\textquoteright}s Waitangi Angora flock, were used to obtain estimates of the effects of age, of dam, sex, rearing rank and birth day (age). Characters studied (and years of birth) in the three data sets were: Set 1: weaning weight and 12-month fleece weight (1978-1986); Set 2: 6-month fleece weight and yearling fleece weight (the sum of both 6- and 12-month fleece weights; 1978-1985); Set 3: 12-month live weight and 12-month fibre measurements of fibre diameter, standard deviation of fibre diameter, percent medullation and percent kemp (1984-1986). The weaning weights of kids out of dams aged 3, 4, 5 and 6 + years were heavier than those out of 2-year old dams by 0.7, 1.0, 1.5 and 1.8 kg respectively (P<0.001). Corresponding differences in 6-month fleece weight were 0.01, 0.02, 0.03 and 0.03 kg (P<0.05). Age-of-dam effects were variable for 12-month live weight and arcsine-transformed percent kemp, and nonsignificant for the remaining traits studied. Males had heavier live weights and fleece weights than females (P<0.001), but differences between the sexes were generally small for the fibre measurement traits. Multiple-reared kids (and later-born kids) had significantly lighter live weights and fleece weights than single-reared kids (and earlier-born kids). Both rearing rank and birth day effects were generally small and not significant for the fibre measurement traits. Heritability estimates for weaning weight, 6-, 12-month and yearling fleece weights, 12-month live weight, fibre diameter and standard deviation of fibre diameter were respectively 0.10, 0.24, 0.25, 0.36, 0.24, 0.51 and 0.21. Arcsine transformation of percent medullation and percent kemp data yielded heritabilities of 0.16 and 0.02 respectively. Subject to the limited number of sires represented in the data sets studied, genetic correlations between 12-month fleece weight and the two live weight traits were negative and of medium magnitude. There were also strong positive genetic correlations between 12-month fleece weight and both fibre diameter and arcsine- transformed percent kemp. Phenotypic correlations among live weight, fleece weight, and fibre diameter traits were all positive and of medium to high magnitude. Corresponding correlations with arcsine-transformed percents medullation and kemp were generally small and positive. It was concluded that direct incorporation of the genetic and phenotypic parameter estimates obtained in this study into selection index calculations, could not be advocated without due attention to the limited sample sizes and associated errors of estimation.}, issn = {1176-5283}, author = {Hogg BW and Catcheside LM and Mercer GJK and Duganzich DM} } @conference {40150, title = {Multiple pregnancy diagnosis of ewes using real time ultrasonic body scanner and video-fluoroscopy systems}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {107-112}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Eighteen entire male Saanen goats (liveweight range 5 to 115 kg; carcass weight range 2 to 52 kg; age range young to mature) and 19 female (liveweight range 17 to 64 kg; carcass weight range 8 to 32 kg age range several months to mature) were slaughtered. Carcasses were dissected into fat, muscle and bone. Based on allometric regression relationships an increase in carcass weight from 10 to 30 kg was accompanied by a decline in carcass muscle from 60.5 to 59.9\% for the males, but from 61.8 to 51.5\% for females. The greater decline in muscle content for the female carcasses reflected an increase in carcass fat content from 10.6 to 33.7\%, while for male carcasses the increase was only from 11.7 to 15.5\%. Over the same increase in carcass weight, carcass bone decreased from 24.7 to 14.1\% for females, but only from 23.4 to 20.4\% for males.}, issn = {1176-5283}, author = {Grace ND and Beach AD and Quinlivan TD and Ward B} } @conference {40130, title = {New Zealand - the sheep seed basket of the world}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {1-4}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Red deer calves (10 of each sex) were immunised at birth against a melatonin conjugate or injected with adjuvant only (10 of each sex). Booster injections were given on 5 occasions over the next two years and effects of immunisation on live-weight gain, pelage and reproductive changes were monitored throughout this period. Immunised stags were 7- 10\% heavier than their controls between 9 and 11 months of age and at 16 and 20 months of age and a similar, but not significant, effect was recorded for immunised hinds. Immunisation did not affect calving date of the hinds, or casting date and time of stripping of the antlers in the stags or pelage changes in deer of either sex. These results indicate that immunisation of red deer against melatonin can modify the seasonal pattern of liveweight changes during their first two years of growth.}, issn = {1176-5283}, author = {Binnie DB} } @conference {40187, title = {A note on the use of number of permanent incisor teeth for determining age in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {303-306}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Lambs in pens were infused duodenally with increasing amounts of casein or a mixture of four essential amino acids (EAA) to examine effects upon N retention. Eight Dorset Down x Coopworth lambs (39+/-1.1 kg) each fitted with rumen and duodenal cannulae were housed indoors and offered freshly cut ryegrass/white clover pasture at a rate of 470g fresh herbage/kgW0.75(MW)/d. The metabolizable energy intake from herbage was approximately 870 kJ/kg(MW)/d. Experimental treatments were duodenal infusions of water (control), 3, 6, 9 and 12g casein/kgMW/d and three levels of a mixture of AA (methionine, lysine, histidine and arginine) in amounts equivalent to the supply of these AA in 3, 6 and 9g casein. Treatments were allocated in an 8 x 8 latin square design. Duodenal non-ammonia N (NAN) flow indicated that 33\% of forage protein N intake was lost across the rumen, the mean flow being 1.46gNAN/kgMW/d. Infusions of casein resulted in significant linear increases (P<0.01) in N balance up to 6g casein/kgMW/d, the casein N supply at this level being equal to the N lost across the rumen from the basal forage. The increase in N balance with infusion of 6g casein was equivalent to an additional 96\% of the N balance observed with the control treatment. No further significant change in N balance was observed with casein infusions greater than 6g/kg/MW/d. A small non-significant response to infusions of 4 AA was observed indicating that these 4 essential AA were not solely responsible for the response. These results indicate that liveweight gain responses can be expected if the losses of protein that occur in the rumen of lambs grazing temperate pastures can be reduced. }, issn = {1176-5283}, author = {Bray AR and Burton RN and Murray MA and Saville DJ} } @conference {40159, title = {Nutrition effects on live weight and reproduction of Cashmere doe hoggets}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {157-162}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Often effective breeding programmes are dependent on the assumption that heritabilities and genetic correlations between traits are the same in both sexes and that the genetic correlation for the same trait measured on both sexes is unity. A total of 12 302 records from 149 sire groups were analysed using mixed model techniques to test these assumptions. The results provide an indication that genetic and phenotypic parameters differ for male and female sheep. Cognizance of this fact should be taken when considering alternative selection strategies.}, issn = {1176-5283}, author = {McCall DG and Clayton JB and Dow BW} } @conference {40164, title = {Observations on resistance and {\textquoteright}self-cure{\textquoteright} to nematode parasites exhibited by grazing lambs and Saanen kids}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {179-182}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The effects of selecting for reduced leaf shear strength in perennial ryegrass on voluntary intake, digestibility and rumen outflow in sheep were studied. Two perennial ryegrass cultivars, selected on the basis of leaf shear strength (LS and HS) were fed to Romney wethers in May and October 1988 indoors for 2 weeks to measure voluntary intakes. Higher daily intakes of LS than HS (102 gDM/kg0.75 v 86 gDM/kg0.75) were recorded in October, but no significant differences were observed in May, apparently as a result of high amounts of dead matter in the herbage. Eight rumen fistulated wethers were fed either LS or HS cultivars in May. Cr-EDTA-Ru-phenanthroline marker solution was infused for 6 days to measure rumen outflow and total faecal collection was made for digestibility determination in May. Total faecal collection was also made in October following the measurement of voluntary intake. In both experimental periods eating behaviour was also recorded. Low digestibilities were observed in May with no significant differences between LS and HS (65\% v 67\%), but in October high digestibility of HS than LS was observed (76\% v 73\%), and also longer rumination times for sheep fed HS than LS were recorded in October (542 min/kg/DM/day v 426 min/kgDM/day). The rate of DM disappearance of herbages containing low amount of dead matter (8\%) when suspended in the rumen of cows, was significantly greater for LS than HS. Further investigations with good quality pasture with low dead matter are suggested.}, issn = {1176-5283}, author = {Watson TG and Hosking BC} } @conference {40170, title = {Performance of visually or objectively culled ewe hoggets}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {215-220}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Ewes from five genotypes (Australian Merino, New Zealand Merino, Romney, Australian Merino x Romney, New Zealand Merino x Romney) were examined over 2 years from April 1986 to March 1988. Maiden 2-tooth ewes were used in the first year and mixed aged ewes in year 2. Ewes were treated with CIDRs (14 d) and joined with vasectomised rams every 6 weeks throughout the year. The incidence of oestrus and ovulation and ovulation rate were recorded. In year 1, there were no discernible differences between the five genotypes in the pattern of ovulation response which ranged from about 100\% in April to 70\% in August, dropping to 3\% in September and then to 0\% until a recover to 100\% in the 4 Merino lines and 70\% in the Romney by March. In year 2, the incidence of ovulation for all 5 genotypes was 100\% for April, May and July. In August, 70\% of the Merino lines and 55\% of the Romney and Romney cross lines ovulated. Only the Australian Merino ovulated in November (8\%) while both Merino lines ovulated in December (Australian 4\%, New Zealand 14\%). However in contrast to Year 1, in January the pure Merino lines showed 100\% incidence of ovulation, the cross breed lines 60\% and Romney 10\%. By March, the cross breed incidence had reached 100\% and the Romney 80\%. These data indicate a marked seasonal pattern of ovulation in all 5 genotypes with some indication of an earlier onset to the breeding season in Merino ewes.}, issn = {1176-5283}, author = {Harvey TG and Baker RL} } @conference {40147, title = {Recent developments in animal breeding programmes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {91-96}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {An experiment was undertaken to compare the palatability and muscle pH of meat from around 30 lambs per group that had over a 7-week period in early winter either gained 11kg live weight, held weight, or lost 11 kg live weight. The cooked longissimus muscle from the gain and loss groups was tested for shear force value using 10 samples from each lamb in a MIRINZ tenderometer. Mean values of 15.5 and 14.2 force score units were recorded for the two groups respectively on a scale where a value of 40 is bordering on tough. A consumer panel rated roast leg meat for overall score, tenderness and flavour and the meat from all treatments was rated highly satisfactory. Mean ultimate pH values from the lambs on all treatments were low. The results indicate that lamb weight loss per se had no adverse effect on the quality of meat. Weight loss did not differentially remove carcass fat compared with other tissues but the tendency was in this direction.}, issn = {1176-5283}, author = {Macmillan KL and Thatcher WW and Drost M} } @conference {40169, title = {Relative wool production of wethers and ewes of different rearing status}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {209-214}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Low growth rates in autumn have been described in cattle and sheep in New Zealand and overseas. Comparison of responses in liveweight gain to herbage allowance has shown that animals grazing in autumn grow much more slowly at all allowances than those grazing in spring. When autumn- and spring-born lambs were grazed together, responses in liveweight gain to varying herbage allowance did not depend on their age and/or live weight. There were large differences between the responses of animals grazing in autumn and those grazing in spring. In autumn, animals grazing pasture previously sprayed with high rates of fungicide at high allowances gained weight 28\% faster than those grazing unsprayed pasture - 107.2 v 83.7 g/d. In spring, the use of fungicide on pasture had no significant effect on liveweight gains of lambs.}, issn = {1176-5283}, author = {Sumner RMW and McCall DG} } @conference {40166, title = {Romney male and female heritabilities and genetic correlations for weaning, autumn and spring body weights and hogget fleece weights}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {191-196}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Five mixed-age Coopworth ewes were offered a pelleted low Mg (1.0 g Mg/kgDM) diet at the rate of 800 g/d for 2 months. Five levels of MG (0, 0.5, 1, 2 and 4 g Mg/d) in 230 ml deionised water were infused into the distal ileum for 48 h, followed by a recovery period of 24 h. The treatments were randomly allocated to each animal using a latin square design. Mg absorption from the large intestine was estimated from changes in plasma Mg concentration and urinary Mg excretion rate. Twelve h after commencement of infusion, plasma Mg concentration was higher at 4 g Mg than at 0g. There was a positive relationship between the amount of Mg infused and urinary Mg excretion. However, the percentage of infused Mg that was absorbed declined from 18.2\% to 6.9\% when Mg infusion rate was increased from 0.5 to 4 g Mg/d. In a second experiment, using a cross-over design, increasing the amount of water infused, with 4g Mg/d, from 230 to 2300 ml decreased urinary Mg excretion. The results show that Mg can be absorbed from the large intestine in significant amounts and indicate that a passive transport mechanism may be involved.}, issn = {1176-5283}, author = {Parratt AC and Nicoll GB and Alderton MJ} } @conference {40177, title = {Seasonal pattern of ovulation in Merino Romney and Merino x Romney ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {249-254}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Effects of liveweight change during pregnancy and ewe shearing on lamb birth weight were studied using highly fecund Booroola-Merino cross Coopworth ewes. Following stratification on the basis of ewe live weight (mean 53.7 kg), age, breed, condition score, and previous (187) litter size, ewes were randomly allocated to a high (H) or low (L) early pregnancy (0.-49 days) nutritional treatment. Ewes on treatments L and H were offered sufficient feed to change their average live weight by 0 and 3 kg respectively between mating and 7 weeks post-mating. On the basis of litter size estimated by ultrasound scanning on day 50 of pregnancy, each of the 2 ewe groups was subdivided and allocated to one of 2 mid-pregnancy nutritional treatments (h and L) designed to change ewe body weight (live weight less conceptus weight) by 3 and 0 kg respectively in 7 weeks. One hundred and nineteen days after mating, half the ewes in each of the 4 nutritional subgroups were shorn and fed to the estimated metabolisable energy (ME) requirement of unshorn ewes. Lamb birth weights were recorded twice daily and within 12 hours of birth for 221 lambs born to 102 ewes conceiving at synchronised oestrus. High level of nutrition of ewes in early pregnancy increased birth weight of lambs by 46 (}, issn = {1176-5283}, author = {Smith JF and McGowan LT and Dobbie JL and Smart SH} } @conference {40135, title = {A study of early venison production from grazing red deer}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {25-28}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Gene maps of livestock will play an important role in the development of new animal breeding technologies based on molecular techniques. The current status of the bovine gene map is reviewed and various methods of mapping genes are discussed. The task of constructing the bovine gene map will be aided by the conservation of chromosomal segments amongst mammalian species. In particular, the detailed maps of man and the mouse can be used to rapidly establish a provisional, but extensive bovine gene map.}, issn = {1176-5283}, author = {Ataja AM and Wilson PR and Purchas RW and Hodgson J and Barry TN and Hay RJM} } @conference {40167, title = {Technical aspects of the Animalplan system}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {197-202}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The relationships between sward height, bite dimensions and bite weight for one-year-old Friesian steers and bulls were examined. Eighteen turfs of uniform area of each of 3 pasture heights (5, 10, 15 cm) were cut from a ryegrass dominant sward in early spring and placed in polystyrene boxes. Sward height was measured prior to grazing and swards trimmed where necessary so that height in the surface horizon was uniform. The turfs were offered over 3 days to 3 bulls and 3 steers in a latin square design so that each animal had 20 bites of a turf of each height daily. Turfs were weighed to the nearest 0.1g before and after grazing. The height of grazed tillers was measured and all pasture was then removed above this height. The turf was then reweighed. Bite weight, depth, volume and area were then calculated for the steers and bulls. There was no significant difference between bulls and steers in bite dimensions. Sward height, which determines bite depth, appears to be the major determinant of bite weight and consequently of daily intake. The technique described has proved to be extremely useful in the study of specific sward structures and their effect on intake.}, issn = {1176-5283}, author = {Johnson DL and Rae AL and Clarke JN} } @conference {40151, title = {Ultrasonic fat depths in Romney lambs and hoggets from lines selected for different production traits}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {113-120}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Forty four feral males, 30 Saanen males and 20 Saanen females, all yearling or younger, were slaughtered and their chemical and dissectible composition determined. The ferals, reared on hill country, were leaner than the Saanens reared on better grazing. Females tended to be fatter than males in most measures of fatness. All three groups were low in fat, both total chemical fat, and dissected fat in the leg. The fat content of lean tissue was extremely low.}, issn = {1176-5283}, author = {McEwan JC and Clarke JN and Knowler MA and Wheeler M} } @conference {40154, title = {Variation in composition and eating quality of New Zealand export beef}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {133-136}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {An experiment ran from mid-October to mid-January to develop pasture height/quality guidelines for optimum doe and kid growth in spring and to test the advantages of integrating goats with other stock classes at this time. Three goat-only farmlets comprised two paddocks with does and kids alternating, 7 days in each. Pre-grazing pasture mass was maintained at 1.6, 2.0 and 2.5 t DM/ha respectively. In three integrated-species farmlets, does with kids grazed from a pre-graze pasture mass of 2.5 t DM/ha for 7 days, followed by the sheep/cattle mob for 7 day. Paddocks were spelled for three weeks before goats were reintroduced. Sheep/cattle mobs comprised, hoggets, yearling steer, or 60\%/40\% combination of the two (respectively). In goat-only farmlets, does lost live weight and kid liveweight gain was reduced when pre-graze pasture mass was below 2.5 t DM/ha. Doe liveweight gain was maximised in the goat/sheep/cattle farmlet. Kid liveweight gain was compromised only on the lowest pasture mass, gain on other farmlets being similar. Sheep and cattle liveweight gains appeared to be unaffected by grazing behind goats when grazing down to 1.5 - 1.6 t DM/ha. Parasite faecal egg concentration (FEC) of does was increased by grazing at low pasture masses with 80\% and 63\% of does being drenched at 1.6 and 2.0 t DM/ha respectively compared to 53\% at 2.5 t DM/ha. Integration with cattle and sheep/cattle reduced FEC (27\% and 17\% does drenched respectively) compared with goats only or goats followed by sheep (53\% and 43\% respectively). In all farmlets without sheep grazing, weed occurrence on transect analysis was over 35\%. The presence of sheep reduced this to approx. 23\% and in the goat/sheep/cattle system weed occurrence was approx. 10\%. Clover occurrence was similar in all farmlets (approx. 50\%) except for the goat/sheep farmlet (approx. 30\%).}, issn = {1176-5283}, author = {Hogg BW and Catcheside LM and Mercer GJK and Duganzich DM and Keiler AH and Ireland TL and Hagyard CJ} } @conference {40134, title = {Water intake of red deer stags consuming dryland pasture or indoors on concentrated feeds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {49}, year = {1989}, month = {Jan}, pages = {21-24}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Exogenous melatonin has been demonstrated to induce early winter furring in farmed mink and fox. In an exploratory trial implants containing either 0, 4, 8, 12 or 18 mg of melatonin (Regulin. Ltd, Melbourne) were inserted subcutaneously in nine groups of ferrets (farmed fitch). The treated groups each consisted of 12 male and 12 female fitch. Forty four untreated fitch comprised the controls. The implants were administered either in mid-January to 8-week old kits or in mid-February to 12-week old kits. At 14-day intervals, all animals were weighed and the 24 hour dry matter consumption of 3 groups (with 0, 8 and 18 mg melatonin implants) measured. All pelts were graded for size, clarity, quality and colour. The melatonin implants caused a significant increase in feed consumption two weeks after administration accompanied by an increase in weight gains. Appetite and weight gains subsequently increased in untreated fitch and weights at pelting were not significantly different between treated and untreated fitch. Melatonin administered in January caused an early, but limited, development of the winter fur pelage. Many of these animals subsequently developed a new winter coat and pelting time was later than for untreated controls. The February treatment caused an advancement in pelt prime by up to 6 weeks compared with control animals (19 April v 1 June). Quality and size attributes of pelts from treated fitch were comparable to control animals. Differences between the various experimental formulations in their ability to maintain high levels of plasma melatonin for long periods was associated with the occurrence of premature moult in some groups. These data indicate that an optimum melatonin treatment strategy has a role on fitch farms in inducing an early pelt prime with savings in feed and labour and increased management control over pelt processing but that suboptimum treatments are contraindicated for this application.}, issn = {1176-5283}, author = {Barrell GK and Topp DF} } @conference {40100, title = {Advancement of the breeding season in Coopworth ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {103-108}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {In 1986 the ovulation rates of 21 Romney ewes selected for facial eczema (FE) resistance (R) and 27 selected for FE susceptibility (S) were recorded on day 5 of the cycle following synchronisation of oestrus with controlled internal drug releasers (CIDR) at the end of April. The ewes were then all dosed daily with 10ml of slurry of a culture of Fasarium containing 6mg zearalenone for 10 d. The ewes were re-examined for post-treatment ovulation rate. The resistant ewes had a higher ovulation rate pre-treatment than did the susceptible ewes (R=1.90 and S=1.50). Both groups showed a decline in ovulation rate after zearalenone treatment (R=1.35 and S=1.22). In 1987 Romney ewes from 4 FE resistance selection flocks (Model resistant (MR) n=148; Model control (MC), n=105; Resistant (R), n=110 and Susceptible (S), n=73) were examined by laparoscopy at the beginning of April. The ovulation rates were higher in the resistant flocks (MR = 1.73; MC = 1.55; R = 1.55; R = 1.42 and S = 1.29). These data indicate that the higher reproductive performance of FE resistant ewes could in part be due to their higher ovulation rates but that resistance to FE confers no protection against the effects of zearalenone.}, issn = {1176-5283}, author = {Smith JF and McGowan LT and Knight TW and MacLean KS} } @conference {40078, title = {Animal productivity and the veterinarian: another perspective}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {1-6}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Two experiments, involving a total 78 Southdown rams from high- and low- backfat lines, were carried out to examine the relationship between subcutaneous fat percent of a rack cut and subcutaneous fat percent of the whole carcass side. A simple regression was as effective as multiple regressions for 30 carcasses (Group 1), but for each equation there was a significant selection-line effect on the intercept. When the usual direct regression coefficient was replaced by an inverse or a geometric co- efficient, the selection line effect was not significant. The 3 prediction equations were evaluated by comparing predicted side subcutaneous fat percent with actual values for a separate lot of 48 ram carcasses (Group 2). The correlation between predicted and actual values was high, but the selection-line effect was significant for all 3 equations. These results serve to emphasis that even within a breed and sex, and for relations with high correlations, there may be problems with the stability of the prediction equations. This could introduce a bias into conclusions.}, issn = {1176-5283}, author = {Fielden ED} } @conference {40124, title = {Calf weaning and summer grazing strategies for efficient beef cow use on hill country}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {237-242}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied}, issn = {1176-5283}, author = {McCall DG and Scott ML and Dow BW} } @conference {40088, title = {Carcass composition of exotic sheep breeds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {53-56}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Clarke JN and Parratt AC and Malthus IC and Amyes NC and Uljee AE and Woods EG} } @conference {40092, title = {Cervical versus laparoscopic AI of goats after PMSG injection at or 48 hours before CIDR removal}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {69-70}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {An experiment was conducted in which 1402 Romney ewes, aged 2 to 5 years, were treated with intravaginal controlled internal drug releasers (CIDR) followed by 1 of 2 pregnant mares serum gonadotrophin (PMSG) preparations (Pregnecol(r), 530 iu v Pharmochem(r), 460 iu) for mating on 1 of 3 dates (December 19, 28 or January 3). Of the 1402 ewes joined with the ram, 71\% conceived to the first cycle. Conception rates, proportion of ewes conceiving multiples and foetuses per ewe joined were assessed by ultrasound pregnancy diagnosis at day 50 of pregnancy. Reproductive performance was highest in 2-year old ewes but not influenced by previous reproductive history (wet v wet/dry in the previous spring). All measures of reproductive performance declined at later mating dates compared with those at December 19. Substantial premiums were obtained for early-born lambs, and for their dams when slaughtered at weaning the following September. Out-of-season lambing systems appear to offer economic benefits in areas characterised by good winter and spring growth rates but dry summers.}, issn = {1176-5283}, author = {Moore RW and Miller CM and Hall DRH and Dow BW} } @conference {40123, title = {Comparative performance and energy metabolism of Jerseys and Friesians in early-mid lactation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {231-236}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The intake, apparent absorption, availability and retention of Se, Cu, Zn and Fe were measured in young lambs using nutritional balance and comparative slaughter techniques. Balances were carried out when the lambs were aged 5 to 11 d, 21 to 28 d, 63 to 70 d and 92 to 98 d. During the first and second balance periods the lambs were fed 175 and 300 g dry matter (DM)/d as milk replacer. In balance 3, 210 g DM/d as milk replacer was fed with fresh pasture ad libitum and during balance 4, only fresh pasture was fed ad libitum. The mean liveweight gain was 250 g/d. The fractions of the ingested mineral which were apparently absorbed on the milk replacer diet were Se 0.95, Cu 0.92, Zn 0.62 and Fe 0.50. These progressively decreased to Se 0.45, Cu 0.10, Zn 0.16 and Fe 0.20 for the all pasture diet. From the comparative slaughter study it was found that 44}, issn = {1176-5283}, author = {L{\textquoteright}Huillier PJ and Parr CR and Bryant AM} } @conference {40084, title = {A comparison of ultrasound backfat measurements on sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {33-36}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Mating records from Dairy Board files for 1984 were analysed. First inseminations with liquid semen were considered, and the effect of several factors on conception analysed. Conception was scored as 1 if a calving occurred 272 to 293d after insemination, and 0 if a calving occurred outside that interval. Only records from animals with a known calving date were included. The data were analysed by linear model techniques, with conception as a dependent variable. The factors contributing to variation in conception were (in order of declining importance): herd, technician, post-partum interval, service sire and age of cow. The R2 was 0.072 indicating that most of the variation is caused by binomial error.}, issn = {1176-5283}, author = {Nicol AM and Jay NP and Beatson PR} } @conference {40110, title = {Components of foam and liquor from the rumen of bloating and non-bloating cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {151-156}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {There is strong evidence that growth hormone (GH) does not enhance lactation through a direct effect on the udder but rather that the effect is mediated by insulin-like growth factors (IGF) -I an/or IGF-II produced by the liver. While plasma IGF-I concentrations rose following GH injection of dairy cows and goats, intravenous infusion of goats with IGF-I did not increase milk yield. However, GH treatment increased the relative binding of IGF-I to a high molecular weight binding protein in plasma. Plasma binding proteins may crucially affect the transport of IGF{\textquoteright}s from plasma to tissues. Plasma IGF-II concentrations doubled during GH treatment of lactating goats. In view of the increased presence of IGF-II receptors in mammary tissue during lactation it is possible that plasma IGF-II is involved in mediation of the GH effect on lactation. The increased partition of nutrients for milk synthesis achieved during GH treatment is facilitated by increased blood flow to the udder. There is little change in the plasma concentration of substrates for milk synthesis. It is likely that the increased blood flow occurs as a metabolic consequence of increased milk synthesis.}, issn = {1176-5283}, author = {Waghorn GC} } @conference {40104, title = {DairyMAN: A Massey University animal management program}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {127-130}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Most cows fed fresh forages containing clover or lucerne have a foamy rumen digesta. When the foam becomes persistent (stable), gasses from fermentation become trapped and the cow bloats. Samples of foam and rumen liquor from bloated and non-bloated cows fed freshly cut lucerne or red clover were analysed to determine differences that may account of foam stability. In a bloated cow the density of rumen digesta falls from about 950 to 600 or 700 g/l and the foam has a density of 200 to 300 g/l. Analysis of foams showed no difference between bloat and non-bloat samples in dry matter (DM)(7.8\%) nitrogen (94 mg/g DM) or chlorophyll (7.4 mg/g DM), but bloat foams had a higher lipid concentration (57 mg/g DM) than non- bloat foams (40 x 10 7/gDM). The significance of these observations are discussed in relation to foam stability.}, issn = {1176-5283}, author = {McKay BJ} } @conference {40113, title = {Detecting inherited variation in DNA sequences and its application in animal science}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {171-180}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A high fleece weight Romney ewe flock was established by selecting the top 0.6\% on greasy weight (GFW) from 32,000 hoggets (average selection differential 40\%). These ewes were mated in 1985 and 1986 by Romney rams with high positive deviations for GFW (selection differentials 48\% in 1985 and 57\% in 1986). Relative to random progeny, the high fleece weight progeny born in 1985 and 1986 had 0.66 kg (28\%) and 0.36 (12\%) higher mean GFWs, respectively. Estimates of realised heritability were 0.45 and 0.22 for the 1985 and 1986 born hoggets, respectively. Two sires used in 1985 had progeny distributions for GFW consistent with their having 1 copy of a single gene for GFW with an additive effect of approximately 1 kg. The single gene hypothesis is being examined by further progeny testing. From birth to hogget shearing the high fleece weight hoggets had a significantly higher live weight than the control hoggets. Fleeces from the high fleece weight and control hoggets did not differ in yield or brightness. The high fleece weight hoggets had greater staple length, fibre diameter and staple strength with lower bulk and greater yellowness. Estimates of the heritability of live weight, fleece weight and wool characteristics agreed with published estimates, as did estimated genetic correlations between GFW and other characteristics. The heritability of brightness was low.}, issn = {1176-5283}, author = {Montgomery GW and Hughes G and Hill DF} } @conference {40108, title = {Development of a dried colostrum}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {143-146}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Inherited protein variation in the blood of domestic species can provide the means to resolve cases of uncertain parentage. In red deer, protein variation has been described from natural populations in Europe, although the inheritance of this variation has not been verified using family data. This paper examines protein variation in the blood of New Zealand farmed red deer and tests the inheritance of each protein variant using family data from 46 matings. The 2 most variable proteins reported in European deer, transferrin and isocitrate dehydrogenase, were also variable in New Zealand farmed deer. The inheritance of variation in each of these proteins was consistent with co-dominant Mendelian inheritance at a single locus. In addition variation was found in plasma proteins in the postalbumins and the gamma-globulins. Variation in the postalbumins was consistent with co- dominant Mendelian inheritance at a single locus while variation in the gamma-globulins did not appear to be inherited. The inherited protein variants identified in red deer provide a blood test which detected 70\% of the possible mismatches between parents and calves in the sample of 46 matings.}, issn = {1176-5283}, author = {Donnelly PE and Petch SF and McLaren RD and Oakley AP} } @conference {40096, title = {The development of an autumn lambing flock of Dorset x Romney ewes without the use of hormones}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {87-90}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Aspects of seasonal physiology were monitored in red deer either untreated or treated with melatonin designed to advance the onset of the natural breeding season. Treated animals were implanted with melatonin at monthly intervals during December, January and February (adult stags and yearling hinds) or January and February (lactating hinds). Rutting behaviour, antler casting and velvet antler regrowth occurred up to 2 months earlier in melatonin-treated stags, while mean calving dates were advanced by 11 d in both groups of treated hinds. In yearling hinds, melatonin treatment advanced by about 1 month the phase of low growth which occurred in control hinds in autumn. However, treatment had little overall effect on live weight of yearling hinds or lactating hinds. Treated hinds moulted their red summer coats and grew lighter winter-like coats about 1 month earlier than untreated hinds. The growth rates of calves sucking melatonin-treated and untreated hinds were virtually identical. These results indicate that melatonin treatment can advance several aspects of seasonal physiology in deer.}, issn = {1176-5283}, author = {McQueen IPM and Reid TC} } @conference {40098, title = {Development of systems for out-of-season lambing at Limestone Downs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {95-98}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {DairyMAN is a computerised dairy herd health and management program recently developed within the Department of Veterinary Clinical Services at Massey University. The program is designed to be a reproduction, health and production recording and analysis system for use on either annual or twice yearly seasonal calving dairy herds. It is intended that the program be used as a management aid for farmers, veterinarians and farm advisors. DairyMAN is able to accept data from a variety of different collection methods, for example the Livestock Improvement Division (LID) notebook, shed sheets, wall charts, mating wheels or formal diary systems. On most farms the current recording system needs minimal modification to accommodate the program. The type of information that may be entered into DairyMAN includes farm, herd and individual cow data. From these data the following reports may be generated: 1. Performance indicators 2. Diagnostic indicators 3. Management aids 4. Simple information collation The program is an example of the development of computer management aids which quickly and effectively analyse herd and farm performance and can target problem areas that need attention. The level of utilization of the program for a single farm will vary depending on the demands of the farmer, his advisor and his veterinarian. Their combined enthusiasm in the farm activities will encourage increased usage of this management aid.}, issn = {1176-5283}, author = {Lowe KI and Carter ML and McCutcheon SN} } @conference {40087, title = {Early growth and reproduction of exotic sheep breeds - a preliminary report}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {49-52}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McMillan WH and Malthus IC and Clarke JN and Amyes NC} } @conference {40095, title = {Effect of nutrition on the ovulatory response of Coopworth ewes to varying doses of two FSH preparations}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {81-86}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The effects of Regulin melatonin implants and type G progesterone impregnated controlled internal drug releasers (CIDR) on the early breeding of F+ and ++ Booroola x Perendale and Waihora Romney ewes were compared in a 2 x 2 factorial trial, melatonin v no melatonin x progesterone. The melatonin plus progesterone and melatonin only groups were implanted with melatonin on 12 December and 23 December respectively. While CIDRs were inserted on 7 January and removed on 19 January, when fertile rams were joined with all treatments. Progesterone alone induced oestrus and ovulations 2 to 9 d after ram introduction in 39\%, 50\% and 11\% of F+, ++ and Romney ewes, whereas progesterone plus melatonin induced oestrus and ovulations in 68\%, 76\% and 44\% of the ewes respectively. There was no response to treatment in terms of percentage ewes lambing. The response to treatment in terms of the percentage of lambing ewes with multiples was different in the 3 genotypes. There was no response to either melatonin or progesterone by the F+ ewes, whereas the ++ ewes responded to both additively, leading to a difference of 50\% between melatonin plus progesterone and the control groups. The Romney ewes responded only to melatonin leading to an overall melatonin response of 21\%.}, issn = {1176-5283}, author = {Thompson JGE and Smith JF} } @conference {40120, title = {Effect of shearing once-yearly in October or twice-yearly in February and October on ewe performance}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {213-218}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied}, issn = {1176-5283}, author = {Sumner RMW and Willoughby LD} } @conference {40112, title = {Effectiveness of drenching Saanen milking does}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {163-170}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The trial reported in this paper was undertaken to determine the potential of using multivariate analyses of blood metabolites to indirectly select for fleece weight. Blood samples from 41 Corriedale rams were analysed for 14 metabolites. A canonical discriminant function of creatinine, urea, magnesium and copper correctly classified 90\% of the cull sheep (on the basis of greasy fleece weight). While limitations to the interpretation of this trial are acknowledged, further work appears warranted, as the cost of analysing the blood metabolites is substantially cheaper than other proposed methods such as gene probes, or electrophoresis protein patterns to select for fleece weight at an early age.}, issn = {1176-5283}, author = {Watson TG and Hosking BC} } @conference {40103, title = {The effects of disease on productivity and profitability of livestock: How should it be assessed?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {117-126}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Selection for and against susceptibility to bloat in herds of Friesian-Jersey crossbred cattle at Ruakura has resulted in cattle of high (HS) and low (LS) susceptibility. Forty one HS and 41 LS animals including 44 cows and 38 bulls were slaughtered between 1985 and 1987 and weights of carcass components and some body organs measured. LS animals had a significantly higher proportion of bone weight and lower eye muscle area, proportions of hindquarter weight and saleable meat in the carcass than did HS animals. This was offset by a 14\% heavier hot carcass weight (HCW) in LS animals. Weights of heart and kidney, adjusted for HCW, were higher and those of mandibular glands were lower, for LS than HS animals. There were no differences between HS and LS herds in adjusted weights of liver, lungs and parotid glands.}, issn = {1176-5283}, author = {Morris RS} } @conference {40101, title = {Effects of melatonin on early breeding of F+ and ++ Booroola x Perendale and Romney ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {109-112}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Glenbrae and Broomfield strains of Corriedale sheep were developed over a period of 19 years by selectively breeding from animals that remained free from clinical footrot when deliberately exposed to natural infection. Recent studies have demonstrated relative advantages in these bloodlines during footrot outbreaks in terms of significantly reduced incidence and severity of infection compared to unselected Corriedales. Similar benefits have also occurred in commercial flocks when first cross offspring of Glenbrae and Broomfield rams were compared to offspring of traditional rams. Introduction to the industry of these apparent genetic gains in footrot resistance has been through 2 approaches. Firstly the Broomfield Corriedale Group Breeding Scheme was established in 1982 with 1420 Sheeplan ewes recorded in 5 flocks screened from an estimated 28,000 ewes. The objective is to breed rams for commercial use utilizing performance records and a footrot challenge prior to selection as 2- tooths. Secondly the Corriedale Sheep Society initiated a top-crossing programme mating 3 Glenbrae footrot resistant rams to 81 registered Corriedale ewes in 1986. Details of these 2 approaches are given.}, issn = {1176-5283}, author = {Moore RW and Miller CM and Dow BW and Staples LD} } @conference {40102, title = {Effects of melatonin on seasonal physiology of red deer}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {113-116}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The effects of various storage/drying procedures of bovine colostrum on the absorption of bovine serum immunoglobulin (Ig) by neonatal kids was examined. Kids either suckled their dams at birth (control) or were fed warmed liquid bovine colostrum which had been either frozen/thawed, frozen/freeze dried or spray dried. After 4 d on treatment protein analysis showed Ig of bovine origin to be present in the serum of all kids fed bovine colostrum. Kid growth and health were good, and did not differ between treatments. Results suggest that the spray process will provide a dried product with the biological properties of unprocessed colostrum.}, issn = {1176-5283}, author = {Fisher MW and Fennessy PF and Milne JD} } @conference {40082, title = {Effects of oestradiol on skeletal growth in lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {25-28}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Growth and hogget reproduction were recorded in Texel, Oxford Down (Oxford) and Finnish Landrace (Finn) purebreds and crosses born in 1985, 1986 and 1987. Border Leicester and Suffolk cross hoggets were included in 1986 and Suffolk cross, Coopworth and Perendale hoggets in 1987. Amongst the purebreds, Oxfords were heavier at weaning than Texels and Finns (100: 92: 89), and as yearlings (100: 93: 88). Amongst the crossbreds born in 1986, Oxfords were heaviest at weaning with Texel, Border Leicester and Suffolks intermediate and Finn crosses the lightest (100: 97: 96: 95: 92). The yearling weight rankings for these 5 crosses were 100: 98: 94: 93: 88. Following entire joining in May after treatment with progesterone impregnated controlled internal drug releasers and pregnant mare serum gonadotrophin, the number of lambs born per hogget joined were, for 1985 and 1986 born purebreds, 1.40 and 1.11 in Finns; 0.76 and 0.96 in Texels and 0.21 and 0.51 in Oxfords. Amongst the 1986 born crosses, Finns ranked highest (1.31 lambs per hogget), Border Leicester, Suffolk and Texel crosses were intermediate (0.61 to 0.65) and Oxfords lowest (0.44). These findings highlight the role of Oxfords for early growth rate and Finns for exceptionally high early reproduction rate.}, issn = {1176-5283}, author = {Mahgoub O and Barrell GK and Sykes AR} } @conference {40081, title = {Effects of rate of weight gain and weight loss on the relationship between carcass weight and GR measurements in cryptorchid lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {19-24}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Purebred Texel and Suffolk sheep have been grazed together at Belclare in Ireland since 1977. The Texel sheep originated from the Netherlands and are of similar origin to those imported into New Zealand. A series of studies have been undertaken to examine the growth and carcass composition of the 2 breeds. Relative to the Suffolk the Texel has an altered growth patter; Texel lambs were 19\% heavier at birth than Suffolk lambs after adjustment for non-genetic effects, but by weaning were 8\% lighter (29.08 v 31.76 kg) and the difference increased to 11\% at 2.4 years of age. The difference between the Purebred Texel and Suffolk weaning weights is approximately double the value that has been reported in large scale crossbreeding trials. Wool production in the Texel was 12 to 22\% higher than the Suffolk breed depending on age. Carcass composition data from 2 separate slaughter trials, using ram lambs, show that the purebred Texel has less subcutaneous fat as a proportion of the carcass than the Suffolk with 75 v 112 g/kg for 18.6 kg carcasses in the first trial and 34 v 80 g/kg and 83 v 125 g/kg when killed at 17.3 and 26.1 kg carcass weight in the second trial. When expressed as a percentage these breed differences are approximately double the values observed in crossbreeding trials. The Texel carcasses also had larger L. dorsi areas and less fat in the internal depots. The food efficiency in the Texel breed was better in the 2 experiments where it was measured, with the differences being significant in 1 trial. Breed differences in composition persisted to maturity with adult Texels having only 78, 81 and 90\% of the weight of subcutaneous, kidney knob, and channel and omental fat deposits relative to the Suffolk. In vivo ultrasonic measurements distinguished similar changes in carcass composition between the breeds with C, Gr and estimated L. dorsi in purebred Texels being 85, 78 and 111\% of Suffolk ewe and ram lambs. The corresponding figures for adult ewes were 79, 83 and 107\%. The carcass composition of most sheep breeds are very similar when expressed as a proportion of mature live weight. The data presented suggests that the Texel is atypical having a modified growth curve and retaining its extreme carcass composition even at maturity.}, issn = {1176-5283}, author = {Thorrold BS and Kirton AH and Cranshaw LJ and Mercer GJK} } @conference {40091, title = {Experiences with artificial insemination in goats}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {65-68}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A flock of 350 to 400 Dorset x Romney ewes was split into autumn- and spring-lambing groups in each of 2 years, 1985-86 and 1986- 87. Joining for autumn-lambing commenced at the end of October, with most mating occurring in late November to early December. Mean lambing date in autumn was 20 April in 1986 and 24 April in 1987. Spring- lambing ewes were joined with rams on 11 March 1986 and 1 April 1987. Mean lambing data in spring was 20 August in 1986 and 6 September in 1987. Liveweight loss over lactation in autumn-lambing ewes was greater than in spring-lambing ewes. Liveweight gain prior to joining was rapid for autumn-lambing ewes, enabling them to reach a live weight of >50 kg prior to joining to lamb in autumn the following year. Number of lambs born per ewe lambing was 110\% and 118\% in autumn, and 146\% and 120\% in spring for 1986 and 1987 respectively. Survival of autumn-born lambs to weaning was 7 to 9\% higher than for spring-born lambs. Lamb growth rates were lower between birth and weaning in autumn- than in spring-born lambs. Autumn-lambing ewes produced up to 0.1 kg more wool than those lambing in spring.}, issn = {1176-5283}, author = {Bowen GM} } @conference {40090, title = {Factors affecting AB conception rates in cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {61-64}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A flock of 224 Dorset x Romney ewes was converted from September lambing in 1977 to 96\% autumn lambing (mean 16 May) in 1983 while increasing flock size by 50\%. Although various techniques of oestrous induction through teasing were used, it was considered that simply introducing entire rams at least 1 cycle before successful tupping was required, eventually gave good results. Four autumn lambing the interval between joining and the first known conception of mature ewe was 35 d during the early years, and declined to 5 d in 1983 to 1987. This decline is suggested to be a genetic change. After the capacity for out-of-season breeding had been developed in all ewes (1982 to 1987), ewes lambing in spring, when subsequently mated to lamb in autumn after a 7 month lambing interval, showed only an 8\% disadvantage in conception over those mated to lamb in the following spring after a 12 month lambing interval. Changes in the flock were brought about by culling of spring-lambing ewes and selection of replacements primarily from early lambers. From 1980, rams born to early lambing ewes were used and their first offspring lambed in 1982. This appears to have had a marked effect on 2-tooth lambing times.}, issn = {1176-5283}, author = {Visser A and Shannon P and Wickham BW} } @conference {40079, title = {Farm factors that influence the eating qualities of lamb meat}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {7-12}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Alternative methods of using an ultrasonic backfat probe on sheep were compared in 2 experiments involving 60 rams. In both experiments, ultrasonic backfat measurements made on the side of the sheep opposite to the location of the operator and the second of 2 measurements had a higher correlation with carcass fat measurement C and were better predictors of percentage carcass fat than measurements taken on either the same side of the sheep as the operator or the first 2 measurements. We conclude that different ultrasound backfat measurements vary in their value in predicting carcass fatness and individual operators should establish the most appropriate measurement.}, issn = {1176-5283}, author = {Bray AR} } @conference {40117, title = {Follicle and fleece characteristics of Merinos, Romneys and Merino-Romney crossbreds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {195-200}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {In the first of 2 experiments, the milk production, food conversion efficiency, and grazing uniformity of Friesians and Jerseys were compared during a grazing trial of 21 d duration in mid lactation. Four groups of each breed, consisting of 12 cows per group, were offered pasture allowances of 10, 20, 30 or 40 kg dry matter (DM)/cow/d. In experiment 2, the energy metabolism of 6 Jerseys and 6 Friesians was compared by means of open circuit calorimetry. Energy balances were established for each cow when offered pasture at ad libitum, and at 75\% National Research Council (NRC) requirements. In Experiment 1, on average Friesians produced 26\% more milk, 6\% more milkfat, 13\% more protein and 24\% more lactose. At the lowest level of feeding (10 kg DM allowance/cow/d) Friesians produced more milk but less milkfat and protein than the Jerseys. Friesians consumed more pasture dry matter (av 13\%), lost more live weight and had a lower food conversion efficiency (61 v 67 g milkfat/kg DM consumed) than the Jerseys. It was calculated that milkfat per ha, at a common live weight was lower for the Friesians than Jerseys particularly at high rates of stocking. Partitioning of gross energy into digestible energy or metabolisable energy was not significantly affected by breed in Experiment 2, but the efficiency of utilisation of metabolisable energy for milk and tissue (balance energy) was higher for Jerseys than Friesians (0.58 v 0.48 respectively). The results suggest that in mid lactation Friesians produce more milk and milk solids per cow than do Jerseys because of the greater feed intake of Friesians. In contrast, the higher food conversion efficiency, utilisation of metabolisable energy and dry matter consumption per unit live weight of Jerseys allows them to achieve a higher production per hectare than the Friesians. Comparisons between breeds at other stages of lactation is warranted, particularly in light of current discussions about the system of payment for milk.}, issn = {1176-5283}, author = {Meikle HE and Wickham GA and Rae AL and Dobbie JL and Hickey SM} } @conference {40107, title = {A genetic approach to footrot control}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {139-142}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Modern methods in molecular biology have immense practical application in many areas of agriculture and veterinary medicine. These methods include the use of enzymes (restriction endonucleases) that recognise and cleave DNA at specific sites, the cloning of specific fragments of DNA into suitable plasmid or bacteriophage vectors, separation of DNA or RNA fragments followed by fixation to a suitable membrane support, and the use of clones radioactive DNA or RNA probes to detect matching sequences by hybridisation. These methods have been combined to provide powerful new techniques to detect DNA polymorphisms that show Mendelian inheritance. Differences in DNA among individuals can be detected as restriction fragment length polymorphisms (RFLP) or by DNA fingerprinting. Both techniques are used extensively in medicine for the analyses of heritable genetic diseases and genetic mapping. They can also be applied to livestock to find DNA markers linked to important economic traits. We have recently begun screening human DNA probes in a search for RFLPs in New Zealand sheep breeds. The objective of the experiments is to find markers linked with Booroola fecundity (F) gene. Several human DNA probes show specific binding to sheep genomic DNA, demonstrating homology between sheep and humans for some DNA sequences. Techniques which identify linked markers will have immediate application in selection for important major gene traits such as genes affecting fecundity, fleece weight, and disease and parasite resistance. New Zealand is in a strong position to apply linkage studies to important production traits in existing breeding programmes.}, issn = {1176-5283}, author = {Moorhouse SR and Skerman TM} } @conference {40086, title = {Growth and carcass traits of purebred Texel and Suffolk sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {41-48}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Feral does were used for a 2 x3 x 2 factorial, with 2 types of insemination (cervical v laparoscopic), 3 pregnant mare serum gonadotrophin (PMSG) levels (no PMSG, 150 i.u. 2 d before controlled internal drug releaser (CIDR) removal and 150 i.u. at CIDR removal) and 2 sperm dose rates (50 v 100 million sperm). The semen, obtained from 9 Cashmere bucks, was frozen in straws containing 100 million sperm. Three operators inseminated 171 does 2 d after CIDR removal. The overall kidding rate from cervical insemination was 24\% and from laparoscopic was 50\%. There was no effect of PMSG, sperm dose rate, buck or inseminator on the percentage of does kidding.}, issn = {1176-5283}, author = {McEwan JC and Hanrahan JP and Fitzsimons JM and Allen P} } @conference {40128, title = {Improving the efficiency of utilisation of pasture protein by sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {253-256}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Two trials were conducted on water intake of red deer stages to provide a basis on which to determine water requirements for deer farms. In the first trial, water intake from a trough by 13 15-month-old deer stags was monitored for 16 days while they grazed dryland pasture during a spell of dry weather (March - April 1988) in Canterbury. Voluntary water intake (VWI) from the trough was 2.6 litre/hd/d and intake of water ingested in feed (40\% DM) was estimated to be 4.2 litre/hd/d, giving a total water intake (TWI) of 6.8 litre/hd/d (or 0.19 litre/kg W0.75/d). In the second trial, 12 3- to 5-year-old stags were held indoors in pens and fed (n=6) either pasture silage (27\% DM) or pellets (88\% DM) in a crossover design with Period 1 of 33 days duration and Period 2 of 25 days. VWI and DMI were monitored daily for 15 days in Period 1 and 14 days in Period 2. TWI for silage was greater than for the pellets (10.6 v 4.6 litre/hd/d, respectively) but the stags drank more water when consuming pellets. There was evidence of a linear relationship between TWI and DMI.}, issn = {1176-5283}, author = {Dellow DW and Obara Y and Kelly KE and Sinclair BR} } @conference {40118, title = {Indirect selection for adult fleece weight using canonical discriminant functions of blood metabolites}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {201-206}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The impact on beef herd performance of weaning calves before or after cows clean-up low quality summer pasture was assessed. Surplus pasture was cleaned-up by weaned cows, and unweaned cows and calves, using either a single hard grazing (1 x 56 d rotation) or 2 x 28 d rotations commencing 20 January in 1986 and 22 January in 1987. Pastures had accumulated about 4.5 t dry matter (DM) /ha after being retired from grazing in late November as a pasture control measure. Weaned calves were fed quality (70+\% green) pasture at pre-graze masses of 1.5, 2.0 or 2.3 t DM/ha under set-stocking 1986, or a fast rotation, 1987. Unweaned calves gained 38 and 39 kg over the 8 weeks in 1986 and 1987, respectively. There was no effect of pasture clean-up method on calf growth. Calves in the best weaned treatment gained just 23 and 30 kg in 1986 and 1987, respectively. Weaned calves suffered from facial eczema (mean gamma glutamyl transferase )GGT) 290 iu) in 1986 which reduced their growth. The rank pasture reduced exposure to facial eczema (mean GGT cows and calves 15 iu) Calf age had no effect on calf growth rates. Weaned cows lost 3 and 15 kg in each year. Unweaned cows lost 20 kg more than weaned cows. Benefits of late weaning were increased calf growth and reduced demand for quality autumn pasture. They were considered to outweigh costs of cow liveweight loss.}, issn = {1176-5283}, author = {Cottle DJ} } @conference {40093, title = {Induction of ovulation in anoestrous red deer hinds with a GnRH analogue}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {71-76}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Mixed-age Coopworth ewes (594) were allocated to 18 groups on the basis of age and live weight. Three groups (n=33) were treated and joined every second month from June 1986 until April 1987. Ewes were treated with controlled internal drug releasers (CIDR) for 14 d and either 0, 400 or 800 iu pregnant mare serum gonadotrophin (PMSG) at CIDR removal. Entire Poll Dorset rams (10\%) were joined at CIDR removal and changed every 6 h during oestrus. Data on interval from CIDR removal to onset of oestrus, duration of oestrus, ovulation rate, pregnancy rate and lambing performance were recorded for all groups. The interval from CIDR removal to the onset of oestrus increased in the non-breeding season and this was modified by PMSG treatment which shorted the interval. The duration of oestrus was shorter in the non- breeding season in ewes with no PMSG and longer in ewes with the higher dose of PMSG. Both dose levels of PMSG prevented the out-of-season reductions in the incidence of oestrus and ovulation. Ovulation rate increased with dose of PMSG and all treatments showed a seasonal change. A decline in conception rate was a major problem even in PMSG treated ewes during the non-breeding season.}, issn = {1176-5283}, author = {Duckworth JA and Barrell GK} } @conference {40094, title = {The influence of abomasal infusion of protein or energy on ovulation rate in ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {77-80}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Mixed-age Coopworth ewes (280) were allocated to an experiment in which the effects of immunisation against androstenedione, synchronisation with progestagen sponges, and exposure to the ram effect, on oestrus and ovulation were examined. The observations were commenced at 2 different times (mid-January and early February) prior to the commencement of the normal breeding season and continued until all ewes had exhibited oestrus and ovulated. Immunisation against androstenedione increased the ovulation rate (+0.60) at the ram-induced ovulation. However it suppressed the proportion of ewes exhibiting oestrus after sponge withdrawal at both times of ram introduction. Ewes isolated from the ram failed to ovulate and the first spontaneous ovulation was not recorded until 6 weeks after that recorded for ewes exposed to the ram effect. Pre-treatment with sponges was necessary for the ram-induced ovulation to be accompanied by oestrus. The extent of the ram effect was most noticeable with 95\% of ewes exposed to the ram ovulating in January.}, issn = {1176-5283}, author = {Cruickshank GJ and Smith JF and Fraser DG} } @conference {40089, title = {The influence of breed on the meat content of beef carcasses for export}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {57-60}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A 2 x 2 x 4 factorial trial was performed (n=20), N=320) to investigate the effect of 2 levels of nutrition (high protein diet -23\% crude protein v low protein diet - 10\% crude protein) on the ovarian response to exogenous follicle stimulating hormone (FSH) administration in mixed-age Coopworth ewes. Two preparations of FSH were examined (FSH-P, Burns-Biotec and Folltropin(r), Vetripharm) at 4 different levels (0, 8, 16 and 24 mg equivalents FSH-P). The ovulation rate of both high and low protein intake ewes increased linearly in response to increasing FSH levels (0 mg = 1.2; 8 mg = 3.2; 16 mg = 7.9; 24 mg = 9.6). There was no difference in response between the 2 sources of FSH. Ewes on a high protein intake had a higher ovulation rate when FSH was not administered (mean ovulation rate }, issn = {1176-5283}, author = {Butler-Hogg BW and Morris CA and Baker RL and Bass JJ and Mercer G and Duganzich DM} } @conference {40114, title = {Inherited protein variation and parentage testing in farmed red deer}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {181-186}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Production data were collected over 3 years from a flock of 600 mixed-age ewes (approximately equal numbers of Romney, Coopworth and Perendale) shorn either once-yearly in October or twice-yearly in February and October. They were grazed as a single mob throughout the year, except over mating when they were divided into breed groups and joined with rams of their own breed. Twice-yearly shearing depressed total annual greasy wool production but did not affect total annual clean wool production. Twice-shorn ewes weaned 7\% more lambs because of a reduction in barrenness. Shearing treatment did not affect live weight either pre-shearing in February or post-shearing in October, nor did it affect ewe and lamb survival. Incidence of casting was less than 1\%. Overall economic returns for the 2 groups of ewes were similar with the greater net wool returns of the once-shorn ewes offsetting the greater net returns from the extra lambs weaned by the twice-shorn ewes. Extrapolation of the observed production trends suggested the net returns from once-yearly shearing pre-joining would be greater than the returns from either once-yearly shearing in spring or twice-yearly shearing pre-joining and again in spring.}, issn = {1176-5283}, author = {Tate ML and Dratch PA} } @conference {40085, title = {Leanness of young sheep that lost weight after shearing}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {37-40}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The necessity to identify and utilize superior fibre producing goats has led to the demand for artificial breeding techniques to be developed within New Zealand. Particular emphasis has been placed on cervical insemination by Ambreed as it is seen as the most cost efficient methods, especially at a commercial level. Bucks have been selected on individual fleece data and stood on licensed artificial insemination centres at Cambridge and Kaiapoi. A total of 50 bucks have been trained for semen collection, with the training period varying from 5 minutes to 2 weeks. Collection from some individuals began as early as December, and continued until August. All semen used was frozen in a Tris-based egg yolk/glycerol diluent. Semen quality has been determined by post-freeze motility using a 2 sec photomicroscopic technique. Training courses lasting for 3 d have been held to instruct both visiting technicians and owner/operator type inseminators. In combination with Ambreed technicians operating directly from Cambridge Centre, approximately 15,000 goats were inseminated during the 1987 autumn period. Kidding data are currently being analysed and indications of pregnancy rate from non-return rates are currently in the 50-55\% range.}, issn = {1176-5283}, author = {Bray AR and Taylor AG and Burton RN and Moss RA} } @conference {40122, title = {Management for milkfat or protein, does it differ?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {225-230}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The utilisation of a supplementary energy supply and its effects on urea metabolism and rumen function were examined in sheep fed indoors on fresh lucerne (Medicago sativa cv. Rere) (N content, 34 g/kg DM). Sheep were fed hourly and infused intraruminally with either water (1200 ml/d; n=5; N intake, 33.0 g/d) or similar volume containing sucrose (160 g/d; n=4; N intake, 32.1 g/d). The additional energy resulted in a lower rumen fluid ammonia concentration (264 v 142 mg N/l). In a comparable experiment with sheep fed chopped lucerne hay, continuous infusion of sucrose also resulted in increased propionic acid levels in the rumen which was reflected in an increase in plasma glucose production (113 v 188 g/d) in the infused group. The results suggest that supplementary fermentable carbohydrate is effective in improving the efficiency of utilisation of pasture protein. The effect appears to be 2-fold: excess ammonia-N i9s captured as microbial protein which is then available for enzymic digestion in the lower gut; the additional fermentative activity increases propionate production which in turn is available for glucose production, thus sparing amino acids for tissue protein utilisation.}, issn = {1176-5283}, author = {Thomson NA} } @conference {40115, title = {Measurement of blood flow and amino acid metabolism in the skin of sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {187-190}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Measuring pasture yields to achieve management goals on farms, or in regions, distant from research stations requires techniques both practical and sensitive to localised factors such as soil type, pasture species, and adapted management technology. In addition, such techniques must be compatible with any quantitative comparisons which need to be made between the farm and the distant research station. Pasture dry matter (DM) yield on a paddock scale is measured by a 2-stage process of yield estimation, and calibration to DM. Using data collected in Northland, this paper shows how the methods of DM yield assessment vary according to the end-use. For example, a cursory eye estimate without calibration is suitable for assessing DM for wintering livestock at high grazing pressure, while, for farm cover assessment, detailed yield estimation allied with detailed quadrat cutting could be necessary. The index of total DM used on research stations can be provided on farms by cutting techniques which measure only to a trimmed level and do not include the stubble component to ground level. The stubble component can be an extract value provided by an expert skilled in comparing different pastures.}, issn = {1176-5283}, author = {Harris PM and Dellow DW and Sinclair BR} } @conference {40121, title = {Measuring pasture yield for livestock management on farms}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {219-224}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Regurgitated and reswallowed rumination boli from 6 diets were collected from oesophageal fistulated sheep. After wet sieving, large particles retained on the 4mm sieve were treated with propan-2-ol and examined under a binocular microscope for types of structural damage. Particle types were identified as leaf, stalf, endodermis and cuticle. Bolus particle composition was different for each diet and for regurgitated and reswallowed material. The overall effect of rumination chewing on bolus composition was to increase the number of stalk particles retained on the 4mm sieve. Surface area (length x width) of particles was determined. Individual red clover leaf particles were markedly larger than all other particle types. Significant differences in individual particle surface area occurred in 2 ways after rumination chewing. For immature and mature ryegrass diets, surface area in stalk and leaf particles increased respectively but red clover, meadow hay and lucerne chaff showed decreased surface area of stalk particles.}, issn = {1176-5283}, author = {Piggot GJ} } @conference {40080, title = {Meat flavour of Romney lambs grazed under Pinus radiata}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {13-18}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Shearing immediately followed by underfeeding reduced carcass fatness in sheep aged 10 to 14 months. When compared with woolly, growing sheep at the same weight a combination of shearing and mild underfeeding lowered GR measurements by 1.5 to 6.3mm in 3 experiments. Although this practice is 1 of only a few management procedures that have been shown to consistently lower GR measurements at a given carcass weight it is not recommended as a routine production practice because of potential effects on animal health and welfare and meat quality.}, issn = {1176-5283}, author = {Percival NS and Hawke MF and Kirton AH and Hagyard C} } @conference {40116, title = {The mechanism of action of growth hormone on milk production of ruminants}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {191-194}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The effect of management on milk, milkfat and protein production was assessed by analysing information collected from 16 different experimental farmlets run over a 9 year period on the Waimate West Demonstration Farm and the Taranaki Agricultural Research Station. In these trials a wide range of stocking rates (2.7 to 4.5 cows/ha), pasture types (ryegrass, lucerne, tall fescue and phalaris) and management systems were used. Comparisons of production and regression analysis between and within years and treatments failed to detect any significant effects of variations in grazing management, stock rate and cow condition at calving on milkfat or protein production. Information from a relatively wide data base, covering a range of seasons, management systems and pasture types suggests that herd management for maximum protein production needs to be no different than for systems already researched and adopted for milkfat production.}, issn = {1176-5283}, author = {Davis SR and Hodgkinson SC and Gluckman PD and Moore LG and Breier BH} } @conference {40125, title = {Optimal cow replacement on New Zealand seasonal supply dairy farms}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {243-246}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The use of computer models to predict the ratio of outputs to inputs can be considerable assistance in developing breeding objectives and assessing research priorities and evaluating the impact of changes in management on efficiency of production in the deer industry. Therefore we have developed a model (based on Parks (1982) which quantifies the inputs of feed and the output of carcass to calculate the biological efficiency of the hind/calf unit over the lifetime of the breeding hind. The model has been used to examine the effects of reproductive lifespan (age of culling), calving rate, twinning, changes in sex ratio and changes in calving date on efficiency. In all cases there was a peak in efficiency at 62-64 weeks of age. In terms of reproductive lifespan, the most efficient sustainable system involved slaughtering hinds after only 3 calvings, although the overall impact of this factor on efficiency was small. Changes in calving rate (proportion of hinds calving) had a marked effect with efficiency declining by 5 to 7\% for a 10\% decline in the calving rate. Twinning also had a major effect with about a 3\% change for a 10\% change in twinning rate although the higher pre-weaning mortality of twins compared with singles would markedly reduce real gains. Changes in the sex ratio also altered the efficiency of the system by 3 to 4\% per 10\% unit change in the proportion of males. In contrast, advancing the calving rate by 3 or 6 weeks did not change efficiency or live weight of progeny at the same age but did result in a 2.8\% increase in live weight at the same date for every 3 weeks advancement in calving.}, issn = {1176-5283}, author = {Harris BL} } @conference {40106, title = {Ovulation rates in ewes selected for resistance to facial eczema and the effect of exposure to zearalenone}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {135-138}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Three mobs of mixed age Saanen milking does (n=15) were grazed separately on 3 suites of paddocks during the spring-summer lactation season between 1984 and 1985. Animals within mobs were drenched at 21 d intervals according to manufacturer{\textquoteright}s recommended dose rates with 1 of either ivermectin, oxfendazole or morantel. Ivermectin was given to all stock while not lactating. Seasonal patterns in faecal nematode egg count (FEC) were similar across all 3 groups. FEC regain measured 7 d after drenching suggested that effectiveness of the drench depended on the type used. Faecal cultures indicated that Ostertagia spp. and Trichostrongylus spp. were dominant during the summer months. Does with kids at foot were turned out for 76 d as tracers on the various suites at the end of the first trial. At slaughter, the dominant genus found was Ostertagia while appreciably fewer Trichostrongylus spp. were recovered. Significant differences in total worm burdens were detected between treatment groups. Drenching programmes appeared to have little effect on parasite control on pasture grazed solely by Saanen does. This is attributable to contamination established on pasture as well as the relative ineffectiveness of these types of drenches in this breed of goat when used at rates recommended for sheep.}, issn = {1176-5283}, author = {Smith JF and Campbell AG and Towers NR and Cow NR and McGowan LT and Wesselink C} } @conference {40097, title = {Performance parameters in an autumn lambing ewe flock}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {91-94}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Among the factors influencing the productivity and profitability of livestock, animal diseases deserve special attention because they diminish the capacity of the animal to achieve its inherent potential level of production, for any given feeding and management regimen. Evidence concerning the nature of the various effects of disease is reviewed, and a hierarchy of effects is defined. The major effects are on protein metabolism and secondarily on energy metabolism. Effects on feed intake are also common, but even diseases which severely ravage the wall of the gastrointestinal tract do not appear as a general rule to significantly reduce feed digestibility. The primary effects of disease on nutrient metabolism flow through to various consequential effects on the productivity of the individual animal, and hence on herd replacement patterns and herd improvement. At least some diseases can continue to affect productivity even after the disease has been cured by treatment. Consequently, the adage that prevention is better than cure has a sound scientific basis. Analyses have shown exceptionally high economic returns from disease prevention, commonly 500 to 1500\% return on invested funds. This is much higher than from curative methods in most cases. As veterinary science evolves from a curative approach towards an economically grounded health management approach, veterinarians will make use of evaluation aids through which the economic and practical implications of alternative actions are compared, so that the action most advantageous to the livestock enterprise can be taken.}, issn = {1176-5283}, author = {Reid TC and Sumner RMW and Wilson LD} } @conference {40126, title = {Physical breakdown of forages during rumination}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {247-248}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {This study was carried out to examine the efficacy and safety of an injectable copper (Cu) preparation (Coprin; Cu-EDTA, Pittman-Moore Animal Health, NZ) in deer and sheep. Treatments consisted of an injection of Coprin at three dose rates on two occasions five weeks apart. Liver biopsy samples were taken one week before and one and four weeks after each injection and 22 weeks after the second injection. Approximately 75\% of the dose was present in the livers of sheep one week after each injection. However, while over 90\% of the dose was present in the livers of deer one week after the first injection, less than 65\% of the second injected dose was present after one week. Total plasma Cu was elevated for one week after the second injection only, the increase being proportional to dose rate. Plasma activities of aspartate transaminase, gamma-glutamyl transferase and sorbitol dehydrogenase were transiently elevated after the second injection, although not sufficiently so to indicate a state of toxicity. The product was found to be effective for rapidly increasing the Cu concentration of the liver in both sheep and deer. There appeared to be no significant ill-effects in either sheep or deer at twice the recommended dose for sheep.}, issn = {1176-5283}, author = {John A and Kelly KE and Sinclair BR and Reid CSW} } @conference {40119, title = {Production and characteristics of wool from the hogget progeny of sheep intensively screened for fleece weight}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {207-212}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Dairy farmers made management decisions each season about which cow to replace. At present dairy farmers can use the production index. The production index is an historical measurement of a cow{\textquoteright}s milkfat production ranking, free from the influences of herd environment, age, stage of lactation and herd genetic level. A dynamic programming method is outlined which incorporates genetic, reproductive and economic information. This method ranks cows on their annualised present value. A sensitivity analysis was undertaken and the effects of the changes in the different economic parameters are discussed. The optimal cow rankings produced by the dynamic programming method were shown to be robust to changes in milkfat, manufacturing beef and heifer replacement prices and interest rate.}, issn = {1176-5283}, author = {Hawker H and Dodds KG and Andrews RN and McEwan JC} } @conference {40129, title = {Se, Cu, Zn and Fe metabolism of the young lamb}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {257-260}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied}, issn = {1176-5283}, author = {Grace ND and Watkinson JH} } @conference {40099, title = {Seasonal changes in oestrus, ovulation and conception of Coopworth ewes treated with CIDRs and PMSG}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {99-102}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Recent interest in mating ewes at non-traditional times has increased the risk of sporidesmin poisoning (facial eczema) during mid to late pregnancy and lactation. In this pilot study, autumn mated ewes dosed with sporidesmin during pregnancy were used as a model to study the effects of sporidesmin poisoning on production. Ninety ewes were randomised into 3 equal sized groups and were dosed with either a low (0.125 mg/kg live weight) or moderate (0.250 mg/kg) dose of sporidesmin at 120}, issn = {1176-5283}, author = {Smith JF and Cruickshank GF and McGowan LT and Parr J and Mortimer BJ} } @conference {40111, title = {Short- and long-term effects of intestinal parasitism on growth in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {157-162}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Skin and fleece samples were taken from 637 ewes of Romney (R), Superfine Merino (SFM), Local Merino (LM), Superfine Merino x Romney (SFMxR), Local Merino x Romney (LMxR) and Backcross (BX) (3/4 SFM) genotypes. Secondary to primary follicle ratio (S/P), total follicle density (n(P+S), primary follicle density (nP), mean fibre diameter (MFD), quality number (QN), staple length (SL); total crimp number (TCN); live weight (LWT) and greasy fleece weight (GFW) were evaluated. Differences between the various genotypes, ages, years of sampling and birth/rearing ranks for these follicle and fleece characteristics were analysed. There were between genotype differences in significance of fixed effects. Genotypes having Merino ancestry with much large follicle populations had more significant fixed effects, but year of sampling and birth/rearing rank were seldom significant. Repeatability estimates for follicle and fleece characteristics ranged fr4om 0.44 to 0.89. Total follicle density and primary follicle density were positively correlated but the degree of association was higher between S/P and n(P=S). Both within and across genotypes, the correlations between S/P and MFD were negative. The low correlations between nP and GFW reflect the genotypes studied, nP having less effect on GFW and MFD in breeds with Merino ancestry. Heterosis was estimated in several ways, the means of groups representing the parent breeds being compared with the mean of each generation of the crossbred genotypes. The follicle traits, as well as MFD and QN showed negative heterosis. Live weight and GFW showed positive heterosis in the F1 SFMxR and LMxR groups of 6.84 kg, 5.99 kg and 0.18 kg and 0.47 kg respectively. The crossbreds weighed more and produced heavier fleeces than the purebreds but with no concomitant increase in MFD over the parental breed mean.}, issn = {1176-5283}, author = {Young MJ and Sykes AR} } @conference {40127, title = {Some measurements of ruminated forage particles}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {249-252}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Differences between sheep and deer in the effects of molybdenum (Mo) and sulphur (S) on copper (Cu) metabolism were investigated in two dietary experiments each using 8 animals of each species. The animals were offered a hay diet supplemented (Expt 1) to contain 3, 6, 12 or 24 mg MO/kg DM and 2.3 g S/kg DM or (Expt 2) to contain 6, 12, 24 or 48 mg Mo/kg DM and 5.3 g S/kg DM. The duration of the feeding periods was 35 and 16 days, respectively. With the low S diet (Expt 1) total plasma Cu was changed from the pre- experimental level of 0.75 to 0.63, 0.77, 0.81 and 1.03 mg/litre, respectively, in sheep and from 0.95 to 0.77, 0.79, 0.67 and 1.01 mg/litre in deer. The proportion of trichloroacetic acid (TCA) soluble/total Cu was reduced by 0.05, 0.09, 0.07 and 0.21 in sheep and by 0.01, 0.05, 0.08 and 0.11 in deer. With the high S diet (Expt 2) total plasma Cu concentration changed from 0.81 to 0.82, 0.97, 1.43 and 1.41 mg/litre in sheep and from 1.08 to 0.72, 0.96, 0.88 and 1.21 mg/litre in deer. The proportion of TCA- soluble/total Cu was reduced by 0.20, 0.50, 0.60 and 0.63 in sheep and by 0.05, 0.10, 0.23 and 0.48 in deer. This study has shown that Cu metabolism in sheep is more sensitive than in deer to increasing dietary Mo concentration. While plasma total Cu increased with increasing Mo in the diet in sheep, concentrations declined in deer. This was associated with a greater induction of insoluble Cu in plasma in sheep. In both species increased dietary S enhanced the effect of dietary Mo on Cu metabolism, but deer appeared to be more sensitive than sheep to increasing dietary S concentration.}, issn = {1176-5283}, author = {Kelly KE} } @conference {40105, title = {Sporidesmin poisoning in ewes during late pregnancy}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {131-134}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Forty-eight animals were allocated to 1 of 3 treatments (C = continuous growth; I = infected with 4000 larvae/d of Trichostrongylus colubriformis; P= individually paired with I animals for change in live weight) in a serial slaughter experiment examining the effects of intestinal parasitism on bone and muscle in young growing sheep (25 to 45 kg). Both I and P groups were nutritionally rehabilitated after the I group had undergone an 83 d period of infection. While I and P groups underwent similar changes in live weight during the period of infection, feed intake of the P group became progressively less than that of the I group. By the end of infection I animals were consuming approximately 30\% more feed than P animals. During the period of infection both I and P groups lost live weight. Of the body chemical components, fat was depleted to the greatest degree (48\% loss) followed by protein (23\% loss). While bone displayed growth in external linear dimensions (length = +4\%; diameter = +6\%) there were significant reductions in protein (22\%) and cortex width (33\%). In contrast muscle showed decreases in all chemical components and in diameter. This greater effect on muscle was exaggerated in the I group. Infection led to greater reductions in muscle protein (45\% v 34\% (I v P)) and muscle diameter (19\% v 8\%). There were no appreciable differences between the I and P groups for changes in bone variables. While specific effects of infection on growth of muscle were found, change in most variables was largely attributable to the general restriction in growth consequent upon undernutrition. Subsequent to the period of parasitic infection, compensatory growth occurred such that muscle recovered relative to bone. There was some evidence that full recovery of muscle relative to bone was delayed in animals recovering from a parasitic infection.}, issn = {1176-5283}, author = {McMillan WH and Dockrill G and Towers NR} } @conference {40083, title = {The stability of the relationship between subcutaneous fat percent in the rack and the side for Southdown ram carcasses}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {29-32}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The carcass composition of pasture-fed crossbred ram lambs of the Finn, Texel, Oxford Down, Border Leicester and Suffolk breeds was compared at the Hopuhopu Animal Quarantine and Research Station in 1987. Early results were in close agreement with overseas studies which have highlighted the low subcutaneous fat depth of Texel crossbreds in comparison with lambs from Suffolk sires at the same carcass weight. Finn crossbreds were relatively lean subcutaneously but had relatively more kidney fat. Texel crosses showed superior eye muscle development at constant carcass weight.}, issn = {1176-5283}, author = {Kadim IT and Purchas RW and Rae AL and Barton RA} } @conference {40109, title = {Weights of some body organs from cattle selected for high and low susceptibility to bloat}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {147-150}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {This paper reports preliminary studies to determine the normal variation in blood flow, amino acid uptake and protein metabolism in a defined area of skin on 45 kg Romney wethers. Four sheep were catheterised in branches of the deep circumflex iliac artery and vein to allow measurement of arterio-venous concentration differences and blood flow (using dye dilution techniques) in a 560 cm}, issn = {1176-5283}, author = {Carruthers VR and Morris CA} } @conference {40060, title = {Accessing of slaughterhouse information to livestock production systems}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {47}, year = {1987}, month = {Jan}, pages = {85-87}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The trial reported in this paper was undertaken at the Rotomahana Research Station to compare the performance of sheep of different genetic background and breeding history. Border Leicester, Coopworth and Romney rams from different sources were mated to Romney ewes representing a wide range of genetic sources between 1979 and 1983. Rams from 6 Romney strains were sampled including a commercial industry sample, the Ruakura High Fertility (RHF) flock, a Romney stud and 3 group breeding schemes. The Coopworth ram source was also a large group breeding scheme. Data collected on the first cross females born between 1979 and 1983 and lambing between 1981 and 1985 are summarised in this paper. Analyses of ewe hogget performance (growth, wool production and oestrous activity) revealed relatively minor variation among the 6 Romney strains, with the exception of greater oestrous activity in RHF-sired hoggets. Coopworth and Border Leicester crosses were heavier, had higher fleece weights and showed more oestrous activity than straightbred Romneys. Highest reproductive performance was obtained from Coopworth and Border Leicester crosses reflecting breed differences, positive heterosis and heavier ewe body weights. Among the 6 Romney strains greatest variation in reproductive performance was seen for litter size with the RHF-sired ewes excelling and also having the best performance for lambs weaned per ewe joined and lambs weaned per ewe joined as a ratio of ewe body weight. Similarly, the litter size advantage for ewes sired by rams from the 3 Romney group breeding schemes demonstrated that selection for reproductive performance over a period of 10 to 15 years has been successful.}, issn = {1176-5283}, author = {Hathaway SC and McKenzie AI} } @conference {40040, title = {Agricultural education in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {47}, year = {1987}, month = {Jan}, pages = {1-6}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Waste by-products and crop residues are a valuable source of feed for ruminants. In many instances low feed quality and acceptance limit the utilisation of these resources. The main factors influencing acceptance are the chemical and physical characteristics (palatability factors) of feedstuffs and the dietary experience and social environment of the animals. The likely acceptance of a new product, relative to that of many other rations, can be predicted from its position on a preference scale. Exposure of sheep or cattle to feedstuffs early in life can produce large increases in the rate of acceptance of, and proportions of animals consuming, typically unpalatable items. It is clear that by manipulating early feeding experiences and other factors determining ration acceptance the utilisation of by-products and residues by livestock can be increased substantially.}, issn = {1176-5283}, author = {Anderson RD} } @conference {40058, title = {An assessment of the rate of fat accumulation in ruminant adipose tissue in vitro}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {47}, year = {1987}, month = {Jan}, pages = {77-79}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The cold resistance (CR) of 468 new-born lambs was measured by immersion of lambs in a progressively cooling water bath. The ability to withstand cold (CR time) was defined as the time taken from the start of water cooling until the lamb{\textquoteright}s rectal temperature reached 35}, issn = {1176-5283}, author = {Lewis KJ and Molan PC and Bass JJ} } @conference {40043, title = {Barley consumption by lambs during transfer from pasture to barley-based diets}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {47}, year = {1987}, month = {Jan}, pages = {17-19}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Stocking rates and target live weights to optimise profit on a small bull beef unit were determined from the New Zealand Exporters Schedule for bull beef and liveweight gain information. The targets were to purchase bulls during October or November at 85 to 100 kg live weight and to grow them to between 420 and 440 kg live weight by 1 December the following year. Using average pasture growth rate data, a simple feed budget model predicted mean pasture cover targets from April to December required to achieve the live weight targets. Grazing plans were designed and regularly reviewed to test the validity of using mean pasture cover as an indicator of successful management.}, issn = {1176-5283}, author = {Bray AR and Moss RA and Burton RN} } @conference {40044, title = {Behavioural factors influencing by-product and residue acceptance by livestock}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {47}, year = {1987}, month = {Jan}, pages = {21-23}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {This paper reports on an interactive, user-friendly microcomputer based pasture production model which provides pasture growth rate information for farmers and advisers. The model (GRASS) describes the production of perennial ryegrass and white clover pastures in terms of simplified major processes. The model not only allows for assessments of historic and current (daily) growth rates, but can also make rapid analyses of future pasture growth rates. This predictive ability is of major importance in many management decisions. The model also allows for on-site calibration. It is intended to be used on individual farms and any management can be simulated. This model overcomes the limitations of pasture growth data collected at research stations over a limited number of years using standard cutting techniques at sites which are often not representative of the climate and soil types on a particular farm. Examples of potential uses for the model are given. It is concluded that an explanatory low resolution model appears to be a promising approach for more sophisticated feed planning and management decisions.}, issn = {1176-5283}, author = {Matthews LR} } @conference {40057, title = {Bone growth and muscularity}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {47}, year = {1987}, month = {Jan}, pages = {73-75}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Highly prolific flocks of Romney, Coopworth and Perendale sheep have been established from the progeny of ewes screened from industry. Ovulation rates of 1.5-year-old Romney, Coopworth and Perendale ewes were 1.82, 2.08 and 1.87 respectively. Corresponding ovulation rates for older ewes were 2.13, 2.27 and 2.07. Mean litter size of 1.5-year-old Romney, Coopworth and Perendale ewes was 1.63, 1.87 and 1.61 respectively and for older ewes the respective litter size was 1.88, 1.94 and 1.78. The proportion of ewes twinning ranged from 0.57 to 0.69. Within the flocks there are some family lines which are showing outstanding prolificacy and are the subject of a progeny testing programme.}, issn = {1176-5283}, author = {Young MJ and Sykes AR} } @conference {40068, title = {Bull beef production on hill country}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {47}, year = {1987}, month = {Jan}, pages = {119-122}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The aims of this study were to compare ovarian and oestrous activity in ewes teased over a range of dates in late anoestrus by either rams or bucks. Entire Dorset rams or feral bucks (male goats) were joined with anovular Romney ewes on either January 20, 27; February 3, 10 or 17 in a 2 x 5 factorial design (N=350). Ovulations were determined 4 d later and first oestrus up to 6 weeks later. On day 8, ovulations were determined in ewes anovular on day 4 to buck teasings. Spontaneous ovulations first occurred in mid February. Rams were more effective than bucks at inducing ovulations. Furthermore, rams induced ovulations in ewes that failed to respond to bucks. Date of teasing had no effect on the pattern of first matings in ovulating ewes. Ewes stimulated to ovulate by rams tended to display oestrus earlier than ewes stimulated by bucks. These results demonstrate that rams and bucks will initiate early ovulation and oestrus in ewes, but rams are superior teasers to bucks.}, issn = {1176-5283}, author = {Journeaux PR and McRae AF and Parker WJ} } @conference {40063, title = {A comparison of lamb growth rate and lean carcass gain within and among farm flocks}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {47}, year = {1987}, month = {Jan}, pages = {99-100}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The viability of a number of bull beef production systems integrated with sheep, within summer dry and summer wet hill country environments were examined using a spreadsheet feed budget simulation model. A survey of commercial hill country farmers was also undertaken to identify on-farm problems and opportunities. The study demonstrated that bull beef systems can be profitably integrated with sheep on hill country, and that farming bulls for beef on hill country is likely to increase. Survey farmers had few problems with bull misbehaviour and had achieved liveweight gains similar to or higher than those used for modelling purposes throughout the year, although not consistently during the autumn and winter. These farmers could improve profitability by setting up a separate wintering area for bulls or integrating their grazing with ewe hoggets rather than older sheep.}, issn = {1176-5283}, author = {Geenty KG and Dyson CB and Scales GH and Ward C} } @conference {40067, title = {A comparison of spring and autumn calving for beef cattle production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {47}, year = {1987}, month = {Jan}, pages = {115-118}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Rapid expansion of the mussel farming industry in New Zealand, from an annual production of 300 t in 1977 to about 12,000 to at present resulted from the introduction of the longline system. This simple, efficient, low cost and aesthetically acceptable system allowed the new industry to exploit the rapid growth rate and available supplies of spat of the green-lipped mussel (Perna canaliculus). Spat supplies, food availability and market expansion are possible constraints on the continued growth of the mussel industry. The economics of growing, harvesting, processing and marketing hold the key to the industry{\textquoteright}s future potential.}, issn = {1176-5283}, author = {Montgomery GW and Davis GH} } @conference {40056, title = {Computer aided tomography - comprehensive body compositional data from live animals}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {47}, year = {1987}, month = {Jan}, pages = {69-71}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A proposal for the development of a three-stage computer-based system for the acquisition and retrieval of disease and defect data for lambs slaughtered in export premises is described. Stage 1 is an extension of the existing manual ticketing and administrative routine. A slaughter-line computer keyboard would allow continuous collection of data on an individual flock basis, as well as significantly decreasing meat inspector, processor and information servicing workloads. The data base would also provide a statistical base for regulatory decisions and assist the processor{\textquoteright}s quality control programme. Stage 2 is a vertical integration of the inspection service with other agencies involved in the livestock production system. Long-term aims are promotion of producer efficiency and payment by quality. By accumulating both individual and regional flock health profiles, differential cost-effective processing and inspection programmes can be applied. Production and market-related disease and defect data has wide application as a commercial resource. Stage 3 is an integrated meat inspection system with a national disease and residue surveillance centre.}, issn = {1176-5283}, author = {Young MJ and Garden KL and Knopp TC} } @conference {40069, title = {An effect of copper supplementation on growth of beef cattle in Northland}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {47}, year = {1987}, month = {Jan}, pages = {123-124}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Oestrous synchronisation in ewes is normally achieved using polyurethane sponges containing progestagen. The recent development of silicone elastomer controlled internal drug releasers (CIDR) offers an alternative synchronising technique. The appropriate duration of CIDR treatment and timing of ram introduction has yet to be determined. Romney ewes had a CIDR type G inserted on the same date and withdrawn either 11, 12, 13, 14 or 15 d later (Trial 1). The ewes were joined in single sire groups with 9 rams at CIDR withdrawal. This confounding exists between duration and days since ram matings commenced. Matings were recorded over days 1 to 7 and 15 to 21. Cheviot ewes were jointed in single sire groups with 5 rams at either 30 or 48 h after CIDR withdrawal (Trial 2). Matings were recorded on days, 2 3 and 15 to 21. Pregnancy status was assessed by ultrasonic scanning. In Trial 1 more ewes mated by day 1 following 11 and 15 d CIDR durations than 11 to 13 d durations (10\% and 7\% v 4\%). Apart from this, longer durations were associated with fewer ewes subsequently mating. There was no association between duration of CIDR treatment and return matings, pregnancies to first service or multiple pregnancies. However, overall more ewes were pregnant following intermediate durations. In Trial 2 most of the ewes jointed at 30 h had mated by 48 h. By day 3, nearly all ewes had mated in both groups. Non-return rates (80\% v 63\%) and first service pregnancy rates (70\% v 58\%) were higher in ewes joined at 30 h than at 48 h. The final pregnancy rate was similar in both groups (88\% v 90\%). CIDRs should be timed to be withdrawn at 12 to 14 d to maximise pregnancy rates to 2 rounds of mating when ewes are progressively joined with rams. Joining rams at 30 rather than 48 h after withdrawal results in earlier lambing since more ewes are pregnant to matings at the synchronised oestrus.}, issn = {1176-5283}, author = {Reid TC and Shannon PW} } @conference {40065, title = {Effect of different shearing policies on sheep production in Northland}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {47}, year = {1987}, month = {Jan}, pages = {107-110}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Goat farming as a form of livestock farming has developed in New Zealand since the mid 1970{\textquoteright}s. The main cause for this has been the change in the relative economics of the traditional pastoral farming industries of sheep, beef and dairy cows. Farmers have begun to recognise the husbandry and economic aspects of farming goats and have been developing techniques for profitable ventures. Export earnings from goats approached $4 million FOB in 1983-84 but have varied considerably since with the availability of stock for slaughter, dairy goat product market fluctuations, and stock value changes.}, issn = {1176-5283}, author = {Sumner RMW and Armstrong D} } @conference {40054, title = {The effect of selenium supplementation on milk production in dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {47}, year = {1987}, month = {Jan}, pages = {61-64}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A method for the evaluation of the rate of fatty acid accumulation and recycling in adipose tissue in vitro is described. The influence of insulin on fatty acid accumulation in adipose tissue is shown to be greater than its influence on fatty acid manufacture. This was achieved by the ability of the hormone to reduce the rate at which fatty acid was mobilised from the adipose tissue. It is proposed that studies of the total fatty acid balance in this tissue will provide a better understanding of the effects of hormones on overfatness in meat animals than a study which simply addresses the rate of fatty acid manufacture.}, issn = {1176-5283}, author = {Fraser AJ and Ryan TJ and Sproule R and Clark RG and Anderson D and Pederson EO} } @conference {40076, title = {Effect of steroid immunisation and vaginal artificial insemination on the fertility of synchronised ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {47}, year = {1987}, month = {Jan}, pages = {147-150}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied}, issn = {1176-5283}, author = {Moore RW and Lynch PR and Miller CM and Welch RA} } @conference {40075, title = {The effect of steroid immunisation on the seasonal pattern of oestrus, ovulation and ovulation rate in Coopworth ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {47}, year = {1987}, month = {Jan}, pages = {143-146}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Significant numbers of livestock in New Zealand are now grazed on the understorey of Pinus radiata. Fresh foliage of radiata pine contains aromatic monoterpenes and decaying needles resin acids. As livestock grazed under trees are know to eat both fresh and decaying pine needles, a study was made to find out if the meat quality characteristics of lambs grazed under P. radiata were affected. Groups of Romney wether lambs were grazed for 49 d under P. radiata at 100 and 200 stems/ha and on open pasture (no trees). In addition, 2 groups were stall fed for 21 d with 23 and 21\% of their intake as fresh or decaying pine needles respectively. All the lambs were slaughtered on the same day. Meat samples from each were subjected to a range of meat quality tests. Meat from the lambs grazed under the trees, or consuming fresh or decaying needles had slightly different colour and muscle pH levels, but there were no significant effects on its flavour, aroma, texture, juiciness or tenderness. It was concluded that there are no meat taints associated with lambs grazed under radiata pine.}, issn = {1176-5283}, author = {Smith JF and McGowan LT and MacLean KS and Farquhar PA} } @conference {40051, title = {Effectiveness of the New Zealand brucellosis control scheme for sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {47}, year = {1987}, month = {Jan}, pages = {49-51}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Three trials were completed using 1813 cows in seasonal dairy herds to study the effects of an injection of a prostaglandin F2alpha, dinoprost tromethamine (Lutalyse}, issn = {1176-5283}, author = {Bruere AN and West DM} } @conference {40066, title = {Energy nutrition of young red deer (Cervus elaphus) hinds and a comparison with young stags}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {47}, year = {1987}, month = {Jan}, pages = {111-113}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Salmon farming began in New Zealand in 1976 with the introduction of ocean ranching. With this method of aquaculture, juvenile salmon are reared in freshwater and then released to the sea where they grow and subsequently return as adults at 2, 3 or 4 years of age to the freshwater release point. Two other methods of culture are also being practised, sea cage rearing and freshwater pond culture. With these 2 methods the salmon are reared to market size while fed an artificial diet. The increased rearing costs of these 2 methods of culture is offset by the higher survival of juvenile salmon to market size compared with ocean ranching. With ocean ranging 1-2\% survival is considered the minimum necessary for a successful operation while returns of over 3\% have been received at some hatcheries. Salmon production has increased from about 200 t in 1984-85 season (October to March) to 712 t in 1986-87. Exports in 1986-87 were approximately 353 t valued at $NZ4 million.}, issn = {1176-5283}, author = {Suttie JM and Fennessy PF and Veenvliet BA and Littlejohn RP and Fisher MW and Corson ID and Labes RE} } @conference {40050, title = {Facial eczema in hill country - potential toxicity and effects on ewe performance}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {47}, year = {1987}, month = {Jan}, pages = {45-48}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Milk responses to selenium supplementation were measured in 12 dairy herds of low selenium status as indicated by blood selenium concentrations of less than 150 nmol/l (<12 ug/l). In 4 of the herds milk responses were measured for 2 successive seasons. Milk volume responses to selenium varied from -2.6\% to +10.4\% (mean +4.6\%) and milk fat responses from -4.0\% to +10.2\% (mean +3.7\%). Significant (P<0.05) milk volume responses occurred on 2 farms in the first season and milk fat responses on 2 farms in the second season. A negative relationship (P<0.01) was found between milk fat response (\%) to selenium (FatSe) and blood selenium concentration (nmol/l) (BSe) for herds in their first season of supplementation of:- FatSe) = 9.6 - 0.059 BSe. There was no relation between these parameters in the second season of supplementation.}, issn = {1176-5283}, author = {Sheath GW and Webby RW and Boom RC} } @conference {40062, title = {Genetic aspects of cold resistance in new-born lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {47}, year = {1987}, month = {Jan}, pages = {93-98}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Nine red deer hinds run as 2 groups were fed to appetite on a concentrate diet, indoors, from 5 to 17 months of age. Group food intake and individual liveweight gains were recorded. Food intake varied seasonally with greater amounts being consumed in summer than winter. Similarly liveweight gain was faster in summer than winter. From the relationship between intake and liveweight gain it was calculated that the hinds need 0.52 MJ metabolizable energy (ME)/kg 0.75/d for maintenance and require 55 MJ ME/kg for liveweight gain. These values result in slightly higher requirements for hinds than previously reported. In comparison with age matched stags, hinds have lower amplitude seasonal fluctuations in food intake and live weight and although maintenance requirements are similar between the sexes, stags require less energy for growth.}, issn = {1176-5283}, author = {Wolff JE and Baker RL and Dobbie PM and Ford AJ and Jordan RB} } @conference {40064, title = {Genetic variation among six strains of Romneys and Border Leicester and Coopworth crosses}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {47}, year = {1987}, month = {Jan}, pages = {101-105}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {In an 11 month copper supplementation trial in Northland, weaner steer (initial live weight 210 kg) showed decreased liveweight gain when supplemented with copper, from November to March. Pasture copper concentrations were adequate throughout the trial. Serum copper concentrations tended to be low, especially in spring.}, issn = {1176-5283}, author = {Baker RL and Clarke JN and Meyer HH and Harvey TG and Bigham ML} } @conference {40072, title = {Growth potential and constraints in the New Zealand mussel farming industry}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {47}, year = {1987}, month = {Jan}, pages = {131-134}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Treatment with progesterone impregnated controlled internal drug releasers (CIDR) in early pregnancy can increase ewe reproductive performance. Return mating patterns, pregnancy rates and multiple pregnancies were evaluated in supplemented ewes and hoggets. Supplementation was over the 5 d from day 7 to 9 until day 12 to 14 post-mating. Supplementation had no effect on the pattern and incidence of return matings in ewes. In contrast, supplemented hoggets tended to return later with less returning (18\% v 35\%). Supplementation had no effect on ewe pregnancy rate although more supplemented hoggets lambed to first service (79\% v 56\%, P<0.05). Supplementation increased multiple pregnancies resulting in 23\% more foetuses in ewes and 40\% more in hoggets. The progesterone supplemented sheep may be a useful experimental model for studies in reproductive wastage.}, issn = {1176-5283}, author = {Hickman RW} } @conference {40042, title = {Importance of dry matter content to voluntary intake of fresh grass forages}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {47}, year = {1987}, month = {Jan}, pages = {13-16}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The data from 2 series of trials were used to examine the effects of variation in leaf, green and total allowance on the herbage intake and milk production of dairy cows and the liveweight gain of weaned lambs over late spring and summer. Both the herbage intake and milk production of dairy cows and the liveweight gain of lambs were better related to leaf allowance than to green or total herbage allowance. With lambs, however, there were differences in liveweight gain at similar leaf allowances between experimental periods. These were largely accounted for by the percentage of dead herbage in the pasture. It is suggested that differences in animal performance over late spring and summer may be influenced by the level of leaf mass and dead matter in pasture but not the level of green grass stem.}, issn = {1176-5283}, author = {John A and Ulyatt MJ} } @conference {40070, title = {Livestock diversification in New Zealand involving goats for meat and dairy production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {47}, year = {1987}, month = {Jan}, pages = {125-126}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Two hundred 5-year-old Coopworth ewes were allocated to 4 groups in December 1983. Two groups (1 of which had been given a booster treatment of Fecundin(r) on 21 December) were treated with progesterone impregnated intravaginal sponges and joined with vasectomised Southdown rams on 19 January 1984. Oestrous data were recorded daily and ovulation rate determined by laparoscopy at each cycle thereafter. The other 2 groups (1 of which received a booster on 5 May 1984) were also treated with progesterone impregnated intravaginal sponges and introduced to rams on 1 June 1984. Oestrous and ovulation data were recorded until mid-September. Immunisation had no effect on the percentage of ewes exhibiting oestrus whereas season had a significant effect with an increase from 18\% in January to a peak of 95\% in April. This level of oestrous activity was maintained until the end of July after which there was a rapid decline. The proportion of ewes ovulating showed a similar pattern although peak values were attained early in February. Ovulation rate showed an increase up to March, plateauing until early July, and then declining. Values for immunised ewes were significantly higher than controls and persisted for at least 6 months in the early treatment group. These data show that although immunisation does not adversely influence the pattern of oestrus and ovulation activity in ewes subjected to the ram effect, early treatment appears to prolong the ovulation rate response.}, issn = {1176-5283}, author = {Horton CT and Dawson JE} } @conference {40073, title = {The male effect - a comparison of rams and bucks for teasing ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {47}, year = {1987}, month = {Jan}, pages = {135-138}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied}, issn = {1176-5283}, author = {McMillan WH} } @conference {40052, title = {The New Zealand scheme to accredit goat flocks free from caprine arthritis-encephalitis}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {47}, year = {1987}, month = {Jan}, pages = {53-56}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {X-ray computer aided tomography (CAT) is shown to be a unique method of obtaining data pertaining to body composition in live animals. Comprehensive data were obtained from CAT images, dissection and chemical analysis of 5 sheep. Tissue (fat, lean and bone) volumes are accurately determined. Reference cross-sections are shown to be useful predictors of whole body composition.}, issn = {1176-5283}, author = {Merrall M and MacDiarmid SC} } @conference {40045, title = {Nutritive value of Lotus corniculatus L. containing low and medium concentrations of condensed tannins for sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {47}, year = {1987}, month = {Jan}, pages = {25-30}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A linear programming model has been developed which allows investigation of alternative dairy production systems. Simulation models used in conjunction with the linear programming model were then used to help set performance standards for on farm animal productivity. Information from these model sources is seen as an aid to decision making on farms and as an opportunity for managers to better understand the basic relationships that apply within their farming system.}, issn = {1176-5283}, author = {Waghorn GC and John A and Jones WT and Shelton ID} } @conference {40046, title = {Pasture quality and animal performance over late spring and summer}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {47}, year = {1987}, month = {Jan}, pages = {31-33}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The impact of a facial eczema outbreak on ewe performance, and its link to pasture conditions, was assessed within a farmlet experiment that investigated aspects of managing pasture surpluses in hill country. Late disposal of lambs and grazing steep land during periods of high spore numbers increased facial eczema in ewes. These effects can be associated with grazing lower pasture masses. In addition to clinical facial eczema deaths, there was a 2 - 3\% increase in barren ewes and a 5-7\% reduction in multiple births for every 100 i.u. increase in serum gamma glutamyl transferase levels. Pithomyces chartarum spore numbers were highest in easy contoured and north to north-west facing paddocks and in ryegrass dominant microsites. Numbers were least in south to south-west facing paddocks and in pastures dominated by low quality herbage and/or low fertility demanding grass species. The effects of facial eczema may well be reduced, but not necessarily eliminated, if the variability in potential toxicity is understood and wisely managed.}, issn = {1176-5283}, author = {Butler BM and Hoogendoorn CJ and Richardson MA} } @conference {40077, title = {Post-mating progesterone supplementation in ewes and hoggets}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {47}, year = {1987}, month = {Jan}, pages = {151-154}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Castrate male and female lambs (n=8) received no treatment (O dose) or a silicone rubber implant containing 3 mg (L dose), 22 mg (M dose) or 52 mg (H dose) of oestradiol, respectively. Implants were placed subcutaneously at 8-10 weeks of age (mean weight 20.4 kg) and the animals slaughtered 180 d later. Oestradiol treatment decreased length of cannon bone but increased length of vertebral column and 12th rib. Cessation of growth in an early maturing bone (cannon bone) appeared to be accelerated by the treatment so that length was reduced. Later maturing bones (rib and vertebrae) showed a dose-dependent stimulation of linear growth. It is concluded that oestrogens accelerate the natural process of skeletal maturation.}, issn = {1176-5283}, author = {McMillan WH} } @conference {40041, title = {The potential to increase production efficiency from animal-pasture systems}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {47}, year = {1987}, month = {Jan}, pages = {7-12}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A reduction in nitrogen degradation in the rumen of sheep fed fresh Lotus corniculatus containing 2.3-3.5\% condensed tannin (CT) in dry matter has been demonstrated in two experiments. Protection from degradation appeared to favour amino acids essential (EAA) to sheep so that in the presence of 2.2\% CT, 50\% more EAA and 14\% more non-essential amino acids essential (NEAA) reached the abomasum. Apparent absorption of EAA from the small intestine was 62\% higher, and for NEAA 9\% lower than in sheep fed the same diet where CT was made ineffective by ruminal infusion of polyethelene glycol. An increased absorption of EAA could explain the high nitrogen retention reported in this and previous experiments where sheep have been fed forages containing low to medium concentrations of CT. CT did not affect digestion of carbohydrate fractions in the rumen, or over the whole digestive tract. Aspects of microbial growth, rumen pool size, fractional outflow rates and particle size of rumen digesta were determined and are discussed.}, issn = {1176-5283}, author = {Leaver JD} } @conference {40047, title = {Predicting animal production from pasture}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {47}, year = {1987}, month = {Jan}, pages = {35-37}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The basis and protocol of a national industry-based scheme aimed at controlling the spread of brucellosis in rams is described. It was designed by representatives of the Sheep and Beef Cattle Society of the New Zealand Veterinary Association, the Animal Health Division of the Ministry of Agriculture and Fisheries and sheep breed societies. As a national scheme it involves co-operation between veterinarians, sheep breed societies and farmers as well as the Ministry of Agriculture and Fisheries. Before official adoption of the scheme a considerable number of ram flocks had already been freed from brucellosis by field veterinarians using the highly sensitive and specific complement fixation test (CFT) for diagnosing carrier animals. With the establishment of the scheme results to date indicate that the majority of ram breeding flocks are now brucellosis free with a low overall prevalence of the disease.}, issn = {1176-5283}, author = {Milligan KE} } @conference {40048, title = {Predictive use of a pasture production model on commercial farms: some examples}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {47}, year = {1987}, month = {Jan}, pages = {39-42}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A voluntary scheme directed towards limiting the spread of caprine arthritis-encephalitis (CAE) during a period of rapid growth of the goat industry is described. The scheme was instituted at the request of the goat industry and formulated after consultation with the New Zealand Goat Council, the animal Health Division of the Ministry of Agriculture and Fisheries and representatives of the New Zealand Veterinary Association. Prior to the development of the programme, surveys of the New Zealand goat population indicated that the disease was present in few flocks, largely those containing imported goats of superior genetic merit. The scheme was instituted in 1984 to limit the dissemination of the infected goats throughout the national flock. Testing was initially performed using the agar gel immunodiffusion test (AGID) but some doubts over its sensitivity lead to the development of an enzyme linked immunosorbent assay (ELISA). This test has proved to be both highly sensitive and highly specific and has continued to be used until the present time. As a national scheme it involves some degree of co-operation between practising veterinarians, the various goat breeders{\textquoteright} groups and goat farmers as well as the Ministry of Agriculture and Fisheries who are responsible for administering the scheme. Results to date indicate that a large number of flocks have gained accreditation but a number of people who may be regarded as commercial growers are seeking a second tier scheme to limit the disease within their flocks without achieving accreditation.}, issn = {1176-5283}, author = {Baars JA and Rollo MD} } @conference {40059, title = {Quantitative risk assessment and cost-effectiveness: two important requirements for meat inspection programmes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {47}, year = {1987}, month = {Jan}, pages = {81-83}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Lines of 40 ram lambs of a variety of breeds from 22 farms in Canterbury, and initially weighing between 32 and 40 kg live weight, were assembled on a farm and compared for growth rate and lean carcass gain during 12 weeks. High quality legume dominant pastures were used and changes in carcass measurements obtained from samples of lambs slaughtered at the start and end of the trial. Average growth rates and rates of lean carcass gain among lines ranged from 143 to 252 g/d and 27 to 53 g/d respectively. Lines of specialist meat and short-wool breeds (Suffolk-cross, Perendale and Dorset) had higher average gains than long-wool breeds (Corriedale, Coopworth and Romney). The long-wool breeds showed greater variation in fat measurement GR (S.D. }, issn = {1176-5283}, author = {Hathaway SC and McKenzie AI} } @conference {40061, title = {Reproductive performance of progeny of prolific Romney, Coopworth and Perendale sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {47}, year = {1987}, month = {Jan}, pages = {89-91}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Production data was collected from 400 mix4ded-age breeding ewes on each of 4 farms in the Kaiwaka area for 3 years between 1982 and 1986. Half of the ewes on each farm were shorn once yearly and half twice yearly. Each farm had a different time schedule. The once-yearly shorn group were shorn in either February, June, October or November and the twice-yearly shorn group in October and February, December and June, February and October or May and November respectively. Ewes second shorn in February were heavier at main shearing in October than twice-shorn ewes. Ewe live weight on the other 3 farms was unaffected by shearing treatment. Total clean wool production of twice shorn ewes was greater than once-shorn ewes on all farms with the effect being greater following second shearing in May and October. Mean staple length of the lines of fleece wool reflected the actual interval between shearings and the seasonal wool growth cycle. Mean fibre diameter was a direct reflection of the seasonal wool growth cycle. Once-shorn wools were more discoloured than twice-shorn wools. Wools shorn between May and October were less discoloured than wools shorn between November and February. Frequency of shearing did not affect ewe survival, reproduction rate or lamb weaning weight. Average net wool returns were greater for once-shorn ewes on all farms.}, issn = {1176-5283}, author = {Davis GH and McEwan JC and Howarth MV and Kelly RW and Paterson AT} } @conference {40071, title = {Salmon farming in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {47}, year = {1987}, month = {Jan}, pages = {127-130}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Romney ewes were used for a 2 x 2 factorial trial, 2 injections (boosted) v 1 injection of Fecundin(r) pre-artificial insemination (AI) x controlled internal drug releaser (CIDR) re-insertion v no CIDR reinsertion post-AI. The ewes were all synchronised with CIDRs for the AI carried out intravaginally without a speculum 52 h after CIDR withdrawal. Those ewes failing to conceive to AI were naturally mated at the next oestrus. Fecundin(r) boosting decreased the percentage of CIDR synchronised ewes becoming pregnant to AI (12.6 v 21.3, P<0.01) but increased multiple pregnancy rate (50.4 v 30.2, P<0.001) at the subsequent natural mating. Reinsertion of CIDRs for 5 to 8 d, 9 to 12 d after removal of the first CIDR had no effect on pregnancy rate to AI. The response to Fecundin(r) boosting in terms of multiple pregnancy rate at the natural mating was essentially the same in light ewes as in heavy ewes.}, issn = {1176-5283}, author = {Todd PR} } @conference {40055, title = {Some effects of injecting a prostaglandin F2 alpha (Lutalyse) during the post-partum period on the subsequent fertility of dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {47}, year = {1987}, month = {Jan}, pages = {65-68}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The need to determine the scientific base and cost-effectiveness of traditional inspection methods is particularly important in New Zealand, a major exporter of sheep meat. Risk assessment as applied to potential human health hazards in a broad sphere can also be adapted to risk associated with a meat inspection programme. Risk associated with an export inspection programme aimed at maintaining market access must include human health, animal health and aesthetic defects. A quantitative risk assessment model is described for 2 different inspection methods for liver fluke (Fasciola hepatica) in adult sheep. Unless sensitivity and specificity data are produced, quantitative risk assessments are statistically invalid. Determination of specificity also allows cost-benefit analyses to be correctly performed.}, issn = {1176-5283}, author = {Macmillan KL and Day AM and Taufa VK and Henderson HV and Allison PA} } @conference {40074, title = {The timing of CIDR withdrawal and ram introduction on ewe fertility}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {47}, year = {1987}, month = {Jan}, pages = {139-142}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {If predictions for future growth of New Zealand{\textquoteright}s exports of chilled lamb meat are to be fulfilled, overall quality will have to be maintained at a consistently high level, and properties like storage life and appearance will require emphasis. A review of scientific literature showed that a wide range of farm practices can influence meat quality. The trend to breed leaner lambs, to slaughter more ram lambs at heavier weights and older ages in winter and spring, and effects of stressful experiences before slaughter, were seen as areas of potential concern for the production of high quality meat. However, it has not been established that these factors are of economic importance to the meat industry. It is suggested that they should be investigated as possible constraints on the future development of markets for premium quality lamb.}, issn = {1176-5283}, author = {McMillan WH} } @conference {40053, title = {Trends in monthly milkfat production of cows in seasonal dairy herds in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {47}, year = {1987}, month = {Jan}, pages = {57-59}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Changes in shape of the femur and the m. semitendinosus occurring with developmental growth are described. It is shown that three-quarters of growth in muscle volume is consequent upon growth in length of bone, while shape changes in muscle account for only one quarter of growth in muscle volume. Attention to the role of bone is necessary in studies of muscle protein synthesis and muscle growth.}, issn = {1176-5283}, author = {Macmillan KL and Henderson HV} } @conference {40049, title = {The use of a pastoral computer model - a learning experience}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {47}, year = {1987}, month = {Jan}, pages = {43-44}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Records from cows in herds which were production tested by the Auckland and Taranaki Livestock Improvement Associations from 1960 to 1984 were used in regression analyses to estimate trends in milkfat (mfat) production each month from August to May. The average annual increase in production was 0.84 kg mfat/cow in Auckland compared to 0.75 in Taranaki. This meant that over the period from 1960 to 1984, the estimated increases in production were 20.2 and 18.0 kg mfat/cow in Auckland and Taranaki respectively. In Auckland 14.2 kg of this increase occurred in September, October and November. The increase in Taranaki in these 3 months was 10.6 kg mfat/cow. Annual increases in production per cow would be greater if the rate of decline in daily production during summer (from December to February) could be reduced. No consistent increases in production have occurred during the autumn because of highly variable seasonal factors.}, issn = {1176-5283}, author = {Ridler BJ and Stachurski LJ and Brookes IM and Holmes CW} } @conference {40018, title = {Advancement of breeding in non-lactating adult red deer hinds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {175-178}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied}, issn = {1176-5283}, author = {Moore GH and Cowie GM} } @conference {40030, title = {Artificial insemination in sheep - comparison of storage time, dose rate and insemination technique}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {229-232}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {In 1984 selected Oxford Down (O) and Texel (T) sheep in Denmark and T and Finnish Landrace (F) sheep in Finland were purchased or leased and then assembled for treatment. The ewes were synchronised and superovulated before being subjected to surgical embryo recovery. Recovered embryos with at least 8 cells and intact zona pellucida were then deep frozen. The mean ovulation rate, number of eggs recovered and embryos frozen from the O and T in Denmark were 5.4, 4.4, 1.5 and 7.1, 5.0 and 3.0, respectively. Results for T and F in Finland were 7.5, 4.9, 4.1 and 10.0, 7.0 and 5.8, respectively. A total of 548 embryos was imported into New Zealand. Two-hundred and twenty embryos were thawed and transferred to Coopworth recipients in March and 46 in May 1985. The percentages of embryos surviving to term for the various breeds in March and May were: Denmark 0, 43 and 20; Denmark T, 59 and 7; Finland T, 59 and 55; Finland F, 64 and 50, respectively. Thirty-two Coopworths were inseminated with thawed F sperm deposited via endoscopy and 24 (75\%) lambed producing 28 lambs. The importation of both embryos and semen was very successful.}, issn = {1176-5283}, author = {Harvey TG and Johnson DL and Baker RL and Trust BK and Thomson BC} } @conference {40021, title = {Benefits and incentives available from objective measurement}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {186-189}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied}, issn = {1176-5283}, author = {Wiggins LK} } @conference {40012, title = {Calving date effects on beef cow productivity}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {149-152}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {An agonist of gonadotrophin releasing hormone (GnRH) improves dairy cow pregnancy rates when injected at an appropriate stage after insemination. These studies were extended to ewes and hoggets in a series of trials to determine the effects of a single injection of GnRH made at varied intervals after mating. All sheep were mated at a synchronised oestrus (day of oestrus = day 0) with treated ewes being injected on a set date with 2 or 4 }, issn = {1176-5283}, author = {Smeaton DC and McCall DG and Clayton JB and Dow BW} } @conference {40035, title = {The cause of reproductive loss in Gisborne-East Coast ewe flocks}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {251-254}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The relationship between lamb growth rate and ewe milk yield was examined using 213 ewe-lamb sets in 6 experiments. Factors included ewe breed, lamb rearing status, herbage allowance, lambing date and season. Lamb growth and ewe milk production were greater for twin- than single- lamb groups, for Dorset than Romney ewe breeds and for late than early lambing dates. Ewe live weight showed the reverse trend. Regression parameters indicated lamb growth rate was generally more dependent on milk supply during the first 6 than during 12 weeks of lactation. The exception was Romney ewes with low milk production rearing twin lambs. Comparisons among groups of regression coefficients and nominal ordinates (i.e. growth rate at low milk yield) showed that twin lambs were proportionately more dependent on pasture for growth than singles as were lambs reared by Romney compared with Dorset ewes. Similarly, a high herbage allowance, good seasonal pasture growth and a late lambing date caused a greater contribution of pasture to lamb growth. However, among groups there was much variability in the relationship and generally lamb live-weight gain was a poor indicating of ewe milk yield (approx. r}, issn = {1176-5283}, author = {Jagusch KT and Gray MM and MacLean KS and Towers NR and di Menna ME and McMillan WH} } @conference {40011, title = {Comparison of autumn/winter with spring pasture for growing beef cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {145-148}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Ovine FSH was administered hourly to ewes for 48 h from the initiation of luteolysis. The mean ovulation rates of ewes receiving 2.5 }, issn = {1176-5283}, author = {Reid TC} } @conference {40027, title = {A comparison of rams from fleece weight-selected and randomly bred Romney flocks for intake, wool growth and feed utilisation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {215-218}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Trials undertaken at Rotomahana in 1984 and 1985 examined factors involved in sheep AI and provided a link between Rotomahana and a commercial AI programme. Semen collected and diluted by the New Zealand Dairy Board gave similar conception rates (46\%) to semen collected at Rotomahana (42\%). Results in 1984 indicated that there was a small but non-significant decrease in conception rate with semen storage time up to 15 hours (5 h 68\%, 10 h 61\%, 15 h 57\%). In 1985 there was a highly significant difference between 5 and 20 h storage (46\% v 25\%) and this result was consistent over ewe ages and dose rate. In 1985, 200x10 6 sperm dose was compared to 100x10 6 dose in 3 subtrials. The overall conception rates were 45.7\% and 37.5\% respectively (P<0.05). In 1984 diluted semen stored in glass and inseminated using a fine glass pipette gave a higher, but not significant, conception rate than semen stored in mini straws and inseminated using a standard cattle pistollet (66\% v 58\%). In 1985 all semen was stored in glass and inseminated with either a glass pipette (conception rate of 49.8\%) or a cattle pistollet (43.2\%). This difference was non-significant, although there was a significant interaction of insemination equipment with dose rate. A significantly higher conception rate was achieved for cervical (52.8\%) than blind insemination (29\%) when ewes were inseminated {\textquoteright}on time{\textquoteright} in 1985 and this effect was consistent over dose rate. There was no difference in conception rate when {\textquoteright}on-oestrus{\textquoteright} insemination was compared to {\textquoteright}on-time{\textquoteright} (63\% v 61\%). All first-order interactions among the effects of storage time, insemination method and {\textquoteright}on-oestrus{\textquoteright} v {\textquoteright} on-time{\textquoteright} were non-significant in the 1984 trial.}, issn = {1176-5283}, author = {McClelland LA and Blair HT and Wickham GA and Brookes IM} } @conference {40007, title = {The consequence for feed dry matter intake of grazing sheep, cattle and goats to the same residual herbage mass}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {125-128}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {On 6 Taranaki hill country farms, the effect of herbage mass and composition on the growth of lambs from birth to weaning was studied. On each farm 2 representative paddocks were selected and set-stocked with ewes from before lambing to weaning. Ewes and lambs were weighed at docking (early October), mid-November and at weaning in mid-December. Pastures were assessed fortnightly for herbage mass and composition. From docking to mid-November, no association between herbage mass and live-weight gain was found. The only factor influencing live-weight gain of ewes and lambs over this period was the percentage of green leaf material in the pasture. However, the live-weight gains of ewes and lambs from mid-November to weaning were negatively correlated with total herbage mass at lambing. Also over this period, live-weight gains of ewes were positively correlated with percentage of green, and negatively correlated with the percentage of stem, in pasture. With increasing levels of herbage mass at lambing there was associated decline in the percentage of green and increase in the percentage of stem in pastures over the mid-November to weaning period. Despite a large variation in stocking (11 to 26 su/ha) no relationship between stocking rate and live-weight gain of ewes or lambs was found. However, the total live-weight of lambs weaned/ha was correlated with stocking rate. The relationships established between pasture parameters and animal performance and between live weight of lambs weaned/ha and stocking rate indicate that higher spring stocking rates in Taranaki hill country than are presently adopted may decrease herbage mass at lambing thereby increasing the proportion of green herbage which will improve lamb growth and overall production/ha.}, issn = {1176-5283}, author = {Collins HA and Nicol AM} } @conference {39992, title = {Consideration of alternative lamb drafting strategies}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {49-54}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The saleable meat, bone and trimmed fat content was measured on the sides of 643 steer, 273 heifer and 1086 bull carcasses. Saleable meat yield declined from approximately 70\% in grade M to 59\% in grade T for steers and heifers, while fat trim increased from approximately 8\% in grade M to 25\% in grade T. Carcass saleable meat yield in bulls was almost constant (72.6 }, issn = {1176-5283}, author = {Garrick DJ and Purchas RW and Morris ST} } @conference {40031, title = {Development of an effective goat embryo transfer regime}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {233-236}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Low lambing rates are characteristic of ewe flocks on the summer-dry East Coast. In the present experiment, groups of 4- and 6- tooth 54 kg ewes were either kept on, or transferred between, non-facial eczema-prone (NFE) and facial eczema-prone (FE) stations. Two additional groups on the FE station received weekly dozes of zinc and serial blood sampling of all groups identified ewes with a high threshold resistance to FE. Ewes gained 4 kg in the 8 weeks prior to mating. Groups on the NFE station had 3\% barrenness and 55\% twinning; those on the FE station had 18\% and 38\%. Resistance to FE reduced barrenness from 18 to 10\% but did not increase twinning. Estimated lambing percentages were 150 on the NFE station, 113 on the FE. The FE factor was associated with some of the barrenness but most of the reproductive loss appeared due to a factor which imitated an oestrogen. The oestrogenic mycotoxin zearalenone, produced by some pasture Fusaria, was detected in pasture samples collected from the FE but not from the NFE station.}, issn = {1176-5283}, author = {Tervit HR and Goold PG and McKenzie RD} } @conference {40017, title = {Early induction of ovulation in yearling red deer hinds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {171-174}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied}, issn = {1176-5283}, author = {Fisher MW and Fennessy PF and Suttie JM and Corson ID and Pearse AJT and Davis GH and Johnstone PD} } @conference {39988, title = {The effect of different protein/energy intakes on nutritional and physiological parameters in young sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {31-36}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Five Poll Dorset breeders have co-operated since 1982 in a progeny-testing programme to improve lean meat production in their respective flocks. Ram lambs were selected from each flock on their BV{\textquoteright}s for weaning weight (in 4 of the 5 flocks) and were then assessed for fatness (visually and tactually initially, and finally by ultrasonic probe), structural soundness, and muscling. The ram lambs selected for the progeny test were mated at random to Coopworth mixed-aged ewes on a commercial prime lamb property. The progeny were identified to sire and dam and their birthrank indicated by ear-tag. Only progeny born during a 6- to 7-day period were identified in this way. At slaughter in November, information on export grade, carcass weight, and GR measurement was obtained. Heritabilities of carcass weight (CWT) and GR measurement adjusted for carcass weight (AGR) were respectively 0.20 and 0.29 and the genetic correlation between them was -0.09 (based on 29 sires and 490 progeny). To rank the sires, data were analysed on 3 criteria: AGR: carcass lean index (CLI); and a selection index (SI) which included estimates of the relative economic values of carcass weight and GR measurement. Use of CLI was expected to produce the greatest gain in CWT, but least reduction in GR while AGR gave the largest reduction in GR but little gain in CWT. Use of SI would result in intermediate gains in both traits and would achieve the highest increase in financial return carcass.}, issn = {1176-5283}, author = {Waghorn GC} } @conference {40016, title = {The effect of dose level of steroid immunogen on the reproductive performance of ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {165-170}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Red deer comprise over 80\% of New Zealand farmed deer. The larger body and antler weights and faster growth rate of wapiti, originating in North America, have encouraged many deer farmers to hybridise these animals with red deer. This study sought a biochemical marker in blood which could discriminate red deer, wapiti and F1 hybrids. Blood samples were taken from over 200 red deer, North American wapiti, and F1 hybrids. Haemolysed red blood cells were treated with potassium cyanide and subjected to isoelectric focusing (pH range 5 to 8). Starch gel electrophoresis was performed on untreated samples which were scored for both haemoglobin and superoxide dismutase. Haemoglobin from North American wapiti had a higher isoelectric point than that of red deer. Haemoglobin of all F1 hybrids tested showed a double banding pattern representing both parental types. All F1 hybrids were also heterozygous for superoxide dismutase, though this marker was not absolute. It correctly discriminated 95\% of the animals tested. This blood test could be used to verify hybridisation in live deer sales, identify hybrids among captured deer, and select for wapiti if those traits are desired.}, issn = {1176-5283}, author = {Smith JF and McGowan LT} } @conference {40036, title = {Effect of Fusarium culture and zearalenone on the reproductive performance of ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {255-258}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied.}, issn = {1176-5283}, author = {Smith JF and di Menna ME and McGowan LT} } @conference {39987, title = {The effect of post-ruminal infusion of protein or energy on the pathology of Trichostrongylus colubriformis infection and body}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {27-30}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Fat and lean Coopworth ewes that were daughters of fat and lean rams were joined with rams from the Invermay lean and fat selection lines to study the effects of genotype (fat, lean) and mid-pregnancy feeding level on foetal weight and ewe carcass measurements at day 135 of gestation. Ewes offered a high level of feed during days 30 to 100 of gestation gained 3\% while those on a low level lost 9\% of their day 30 live weight. All ewes were offered the same level of feeding from day 100 until slaughter on day 135. Mid-pregnancy nutrition had no effect on foetal weight. Litter size had significant effects on foetal weight (single 4.56 kg, twin 3.99 kg, triplet 3.24 kg). The weight of foetuses of the lean genotype adjusted for litter size and nutrition was 270g heavier (P<0.01) than that of the fat genotype. The weight of placenta, and placentome number/foetus decreased with litter size and were associated significantly with foetal weight. Fat genotype, however, had no effect on placental weight or placentome number. Fat genotype of the ewe and foetus did not affect a number of foetal skeletal size parameters but influenced foetal weight despite ewe nutrition. Consequently it appears that this influence on foetal weight is independent on any effect of the placenta per se.}, issn = {1176-5283}, author = {Bown MD and Poppi DP and Sykes AR} } @conference {40037, title = {The effect of pre-natal nutrition and type of birth and rearing of lambs on vigour, temperature and weight at birth, and weight and survival at weaning}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {259-262}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Future increases in production efficiency of milk production from pasture will be brought about primarily by increasing the genetic potential of cows to produce milk solids, and by developing grazing systems which combine a high level of herbage utilisation/ha with high dry matter intakes. Grazing often under-utilises herbage in spring, which leads to a reduction in quantity and quality of herbage in summer and autumn with a consequent accelerated decline in cow performance. Higher grazing stocking rates in spring combined with the conservation of a greater pasture area for silage produces an improved pasture and provides additional forage for supplementation in summer and autumn. At present the amount and seasonability of milk production in New Zealand is dictated by pasture production. This gives large variations in production between and within years, and may not represent the most efficient way of using milk processing plant or of satisfying the market{\textquoteright}s needs. Consideration may have to be given to less rigid systems of production involving more flexibility in calving date and a greater use of conserved feed.}, issn = {1176-5283}, author = {Moore RW and Miller CM and Lynch PR and Dow BW} } @conference {40014, title = {Effect on ovulation rate of increasing or decreasing ovarian exposure to follicle stimulating hormone during the preovulatory period}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {157-160}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Yearling red deer hinds were treated to advance the time of the normal onset of ovulation so that mating and subsequent calving would occur about 1 month earlier than usual. All hinds, except for the untreated controls had 15 days of intravaginal progesterone treatment beginning on 28 February. At progesterone withdrawal hinds were either untreated, or given pregnant mare{\textquoteright}s serum gonadotrophin (PMS) or gonadotrophin-releasing hormone (GnRH). Stags were introduced on 14 March and the hinds laparoscoped 7 or 12 days later to record the presence or absence of an induced ovulation. Untreated hinds had a very low incidence of ovulation prior to the onset of the normal breeding season. While the use of progesterone alone marginally increased the number of hinds ovulating, PMS or GnRH treatment was generally necessary to induce ovulation. However, assessed from calving records, fertility at the induced ovulation was poor.}, issn = {1176-5283}, author = {Henderson KM and Ellen RL and Savage LC and Ball K and McNatty KP} } @conference {40015, title = {Effects of gonadotrophin releasing hormone (buserelin) on sheep fertility}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {161-164}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Teaser stags and progesterone-PMS treatments were used to advance the breeding season in non-lactating adult red deer hinds. In Experiment 1, 2 vasectomised stags were run with 39 hinds for 15 d prior to joining with entire stags. More teased hinds (20/39) calved early (11-20 November ) than group of non-teased hinds (5/42). In other experiments, laparoscopy revealed that progesterone + PMS treated hinds ovulated in mid February. Although calves were born as early as 10 October, indicating stags could successfully fertilise a hind in mid February, such treatment did not result in many hinds calving in October. It seems that the stag is sub-fertile in February. Calving dates of contiguous control hinds show that a large proportion were mated 18 to 25 d after the induced oestrus in treated hinds indicating red deer stags can have an effect similar to the {\textquoteright}ram effect{\textquoteright}. Some hinds calving to the induced oestrus produced twins.}, issn = {1176-5283}, author = {McMillan WH and Knight TW and Macmillan KL} } @conference {39999, title = {Effects of milkfat yield and conformation traits on retention for a second lactation of Friesian and Jersey-sired cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {83-86}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Data from mature ewes repeatedly re-immunised against androstenedione or oestrone in 3 trials at the Ruakura (Coopworths), Wairakei (Perendales) and Whatawhata (Romneys, Coo9pworths and Perendales) Animal Research Stations, were analysed to estimate the repeatability of ovulation rate and number of lambs born per ewe. Immunisation responses were within the range of those reported previously (Smith, 1985). Between-year repeatability estimates were on average similar for immunised and non-immunised ewes. The unweighted average of the estimate was 0.29 for ovulation rate and 0.009 for number of lambs born, consistent with published values. The results suggest that the joint contribution of genetic and permanent environmental sources of variation to phenotypic differences between animals is similar under both physiological states. The high repeatability of ovulation rate in comparison with number of lambs born supports other published indications of its possible value for improvement of reproductive rate through selection.}, issn = {1176-5283}, author = {Ahlborn-Breier G and Wickham BW} } @conference {40039, title = {The effects of various factors on the relationship between lamb growth rate and ewe milk production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {265-270}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Lambs that had been reared at pasture till 6 months of age were transferred to barley-based diets fed in outdoor yards. Consumption of barley grain was measured daily during the first 4 weeks that it was fed. Highest consumption was achieved when grain was processed and introduced to lambs at pasture before they were transferred to the feedlot. Lambs that received these treatments consumed nearly 800 g/hd/d of barley (air dry weight) within 2 weeks and nearly 1200 g/hd/d within 4 weeks of its introduction. They gained live weight at over 150 g/hd/d during the first 7 weeks of barley feeding with minimal health problems.}, issn = {1176-5283}, author = {Geenty KG and Dyson CB} } @conference {39989, title = {An estimation of the dietary allowances of Cu, Zn, Fe, Mn and Se for single- and twin-bearing ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {37-40}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A model that simulates lamb growth and feed consumption and makes economic assessments on export carcass grading returns is described. It simulates a flock of lambs of specified weight and sex and then, using relationships between live weight, carcass weight and GR, derives grading profiles for various drafting strategies. The option of drafting on the basis of live weight has been compared with options based on GR estimates of high, average and poor accuracy. These drafting policies were evaluated on the basis of several alternative fixed endpoints including total feed consumption, carcass weight and carcass value. Generally results obtained when drafting on GR were better than those based on live weight alone when GR was measured with high accuracy and when carcass weights were high. This model could be useful in making a wide range of evaluations and comparisons other than those reported.}, issn = {1176-5283}, author = {Grace ND} } @conference {39996, title = {Evidence of genetic improvement in the Angus Breeding Scheme of the Department of Lands and Survey}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {67-70}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The relative importance of the currently recorded large number of descriptive conformation traits and of milkfat yield on retention for a second lactation of 6645 Friesian-sired and 5709 Jersey-sired heifers was examined. In a linear multiple regression model, the effect of heifers deviating from the {\textquoteright}normal{\textquoteright} conformation for a certain trait on the retention rate was used as an indicator for the relative importance of the trait. Milkfat yield was by far the most important trait for both breeds. Only a small number of conformation traits describing udder and teats influenced the retention rate significantly. The farmer with Jersey cows appeared to consider more conformation traits as important than the owner of Friesian cows. The results suggest the inclusion of only the important conformation traits describing udder and teats as potential traits in the selection of profitable dairy cattle in New Zealand to retain a high genetic response for milkfat yield.}, issn = {1176-5283}, author = {Nicoll GB and Johnson DL} } @conference {40005, title = {Further development of sheep recording in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {117-120}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Comparisons were made of ewe and lamb weaning weights under 2 lambing dates (6 August and 6 September) with ewes at 2 pre-lambing ewe live weights (52 and 64kg) on 2 levels of pre-lambing pasture mass (approximately 1000 and 400 kg DM/ha) in a 2}, issn = {1176-5283}, author = {Callow CF and Clarke JN and Rae AL} } @conference {40000, title = {Genetic and environmental sources of variation in hogget fleece weight and live weight in Coopworth sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {87-92}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Production systems in France are variable with many localised and adapted breeds, spread among small flocks lambing at different times of the year. In these ways, specialised selection schemes of varying importance and complexity including those designed for improvement of milk production and for out-of-season breeding have been developed. Selection objectives for dairy production concentrate upon milk production with recent attention to total solids content. For meat sheep, lamb production per ewe is important for competitive efficiency. Number of lambs and maternal contribution to lamb survival and lamb growth during suckling are important for the suckling breeds in the South and the improved breeds in easier conditions in the North, the latter also receiving emphasis on later lamb growth and carcass quality. Selection programmes are highly organised nationally under the data- processing control of INRA and the national co-ordination of ITOVIC. Twenty Breed Promotion Committees (UPRA{\textquoteright}s), 77 Professional Advisory Organisations (EDE{\textquoteright}s) and 11 Data Processing Associations (CRI{\textquoteright}s) are involved with a well-structured relationship among them. Selection schemes use different tools to give emphasis to dissemination of genetic merit in addition to ranking animals for breeding worth. The National Recording Scheme provides the common essential ingredient for all schemes. Animal information embraces natural oestrus or induced oestrus, litter size and live weight of lambs. Maternal pedigree is always recorded at birth while paternal pedigree is known if single-sire natural mating or AI is used. Electronic development is being introduced to assist automated collection of live weights and early provision of on-farm flock summaries. AI is used to assist genetic improvement over about 200 000 ewes, mainly dairy breeds. It allows superior ewes to remain on farms - it is estimated that in this way Ai can increase genetic progress by up to 30\%. AI also avoids the need for centralised progeny testing and assists the gene dissemination from superior rams. Nucleus flocks are promoted as centres of gene dissemination only for scarce breeds and for those with very small flock size. Rearing of rams in a central location gives breeding schemes greater control over gene dissemination and organisation of elite matings, especially through AI. Considerable emphasis is given to this aspect of the French breeding programme to ensure effective gene flow for production of the next generation of sires. Central testing stations are also used, mainly to evaluate young meat breed rams which are the progeny of elite matings for growth and carcass merit in a standard environment and as a baseline for live animal performance assessment. Not all the schemes use the same tools in the same way. Breeder commitment and co-operation is nevertheless an important ingredient of the effectiveness in each case.}, issn = {1176-5283}, author = {Warmington BG and Beatson PR} } @conference {39986, title = {Genetic variation in resistance or tolerance to internal nematode parasites in strains of sheep at Rotomahana}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {23-26}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Fifty-six pregnant Romney ewes grazing a ryegrass/white clover pasture were divided into 7 groups of 8 and slaughtered at days 62, 81, 100, 115, 125, 135 and 143 of gestation to remove the conceptus (uterine tissue and membranes, placental fluids and the foetus[es] and determine its total Cu, Zn, Fe, Mn and Se content. The uterus was also removed from 8 ewes just prior to mating. Half the ewes had twin foetuses. The daily rates of deposition of Cu, Zn, Fe, Mn and Se were calculated from the slope of the curves relating the gestational age with the net trace element content of the conceptus. The dietary allowance of Cu, Zn, Fe, Mn and Se for the pregnant ewe was then calculated from the daily deposition rates into the conceptus, determined from this study, and published data on the net requirements for maintenance, coefficients of absorption and DM intakes. The calculated dietary allowances (per kg DM) for single- and twin-bearing ewes, were 7.4 mg Cu, 24 mg Zn, 36 mg Fe, 30 mg Mn and 33 }, issn = {1176-5283}, author = {Watson TG and Baker RL and Harvey TG} } @conference {40032, title = {Haemoglobin type and prolificacy in Booroola sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {237-240}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Groups of 33 Coopworth ewes were drenched with either 25mg zearalenone, Fusarium culture (containing 25mg zearalenone) or water (controls) daily for 10 days pre-mating commencing on day 7 of the cycle following oestrus synchronisation with CIDRs. Reproductive performance was markedly reduced in the ewes treated with zearalenone or the Fusarium culture, with only 9.1\% and 15.6\% of ewes yielding fertilised eggs compared to 57.6\% of the control ewes. Treatment reduced the number of ewes ovulating although displaying oestrus. Treated groups had 46\% of ewes anovular compared to 12\% in the controls. The ovulation rate for those ewes ovulating was less in the treated ewes (1.55) than the controls (1.86). Treatment with zearalenone or FusariumM culture reduced the proportion of egg- yielding ewes that had fertilised eggs (27.3\% and 55.5\%) compared to the controls (100\%). Treated ewes had a markedly longer duration of oestrus and it was evident from corpus luteum size that the oestrus-ovulation relationship had been disturbed.}, issn = {1176-5283}, author = {Dratch PA and Allison AJ and Williams TL and Kyle B and Wyllie JG and Littlejohn RP} } @conference {40029, title = {Hogget oestrus synchronisation: a comparison of CIDR and sponges}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {225-228}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {At 3 months of age, the ovaries of F+ Booroola lambs [i.e. those heterozygous for the fecundity (F) gene] were lighter (P<0.01) than those of ++ Booroola lambs (i.e. those without the F-gene) which were of similar age and body weight. However, the number of follicles (>/= 1 mm diam.) in the above F+ lambs was 1.5 fold greater (P<0.01) than that in the ++ lambs. In lambs of both genotypes, ovarian follicles were active in synthesising testosterone and oestradiol and of reaching diameters which were similar to those of preovulatory follicles in mature ewes. However, none of the ovaries showed evidence of recent ovulations. In Booroola ewes (4 to 8 years of age), the proportions of small ovarian follicles (0.5 to 1.0 mm diam.) that synthesised progesterone, androstenedione and oestradiol in culture were related (P<0.05) to genotype (homozygous, FF > F+ > ++ ewes). Also in the above ewes, follicles in the FF and F+ animals reached maturity at smaller diameters than in ++ animals, namely 3.4 }, issn = {1176-5283}, author = {McMillan WH} } @conference {39985, title = {Immunity to gastrointestinal nematode parasites in domestic stock with particular reference to sheep: A review}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {15-22}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The effect of post-ruminal infusion of protein or energy on the pathology of Trichostrongylus colubriformis infection and body composition in lambs was investigated by a comparative slaughter experiment. Lambs infected with 3000 larvae/d were infused with casein (50.5 g crude protein/d; PI) or glucose (isocaloric with casein infusions; EI) or solvent/diluent (SI). Uninfected controls (C) were also infused with solvent/diluent. Mean live-weight gain }, issn = {1176-5283}, author = {Watson TG} } @conference {40024, title = {Implications of objective measurement for fleece tenderness research}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {200-202}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Two pen-feeding experiments were conducted on Romney rams from fleece weight-selected (FW) and control (C) flocks. In experiment 1, 12 yearling rams from each group were fed cut ryegrass/clover pasture ad libitum for 6 weeks. In experiment 2, 9 ram hoggets from each group were fed lucerne based diets in 3 periods (P1, P2, P3). Individual feeding in P1 was 1 kg/d protein-extracted lucerne; P2, 1 kg/d protein- extracted lucerne plus 0, 30 or 60 g/d formaldehyde-protected casein; P3, 1.4 kg/d chopped lucerne. No differences in intake or liveweight, and no consistent trends in dry matter digestibility were found. FW rams had consistently higher greasy wool growth, this difference increasing with higher intakes and casein feeding. Between rams, the regression of wool growth on intake was positive for FW rams and negative or near zero for C rams. FW rams had greater live-weight gain than C rams when fed chopped lucerne. Differences in wool growth between FW and C rams could not be directly attributed to intake.}, issn = {1176-5283}, author = {Orwin DFG and Geenty KG} } @conference {40023, title = {Implications of objective measurement for sheep management}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {198-200}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Fleeces from 2000 mixed age Merino ewes in each of 6 years were classed traditionally (i.e. by subjective assessment of fineness into 2 or 3 lines) or objectively (i.e. fleeces put into one line). Off-type fleeces (about 10\%) which differed markedly from the bulk of the clip were excluded from all the lines. The fleeces from 800 to 1000 Merino hoggets in each of 6 years were also used in comparisons of traditional and objective classing. The fibre diameter of each objective (OCP) line was very similar to the weighted mean of the corresponding traditional (TP) lines. Clean auction prices for the OCP lines were 0.8\% and 1.0\% lower than the weighted means of the TP lines for the ewes and hoggets, respectively. Research in Australia has shown that there is no difference in the processing performance of traditionally or objectively classed lines of fleece wool. The optimum classing method is therefore determined solely by the relationship between price and diameter. Wools 21 }, issn = {1176-5283}, author = {Sumner RMW and Hawker H} } @conference {40025, title = {Implications of objective measurement of wool for sheep breeding}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {202-205}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Fleeces from 28 000 Romney ewe hoggets in 14 mobs on 7 farms were weighed. Within each mob the top 1\% hogget fleece weight (High) and a random 1\% (Random) were identified, midside sampled and weighed off-shears. Subsequently the top 0.6\% on hogget fleece weight from each mob and a random 0.3\% were transferred to Woodlands Research Station and managed as one flock for the next year. At hogget shearing (9 months fleece) the 14 High sub-groups had an average 1.08 kg higher fleece weights (greasy) and 0.83 kg higher clean fleece weights than the Random sub-groups. There was a close between sub-group relationship between greasy fleece weight and live weight with the High hoggets having 0.78 kg heavier fleeces at the same live weight. The High hogget sub-groups had a higher mean live weight (+3.9kg), fibre diameter (+2.7 }, issn = {1176-5283}, author = {Binnie DB and Elliott KH} } @conference {40006, title = {The influence of sheep to cattle ratios in live-weight gain on pastures grazed to different levels in late spring-summer}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {121-124}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A survey of 30 Wairarapa hill country farmers during 1983 investigated how management practices influenced sheep performance. Lamb growth rates between birth and weaning which ranged from 153 to 300 g/d, were most affected by lambing date and the use of N fertiliser. Pasture cover/SU at lambing was more often a limitation to high lamb growth rates on early lambing farms, but even on later lambing properties insufficient feed at lambing was common. Pasture cover/SU at lambing was most affected by ewe winter rotation length, the use of N fertiliser, stocking rate and stock policies which enabled winter stocking rates to be progressively reduced. Weighing of sheep was associated with the attainment of higher autumn live weights. A high proportion of farmers weighted (63\%), but their knowledge of acceptable live weights was poor.}, issn = {1176-5283}, author = {McCall DG and Smeaton DC and Gibbison ML and McKay FJ and Hockey H-UP} } @conference {39984, title = {Inheritance of active and passive humoral immunity in ruminants}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {5-14}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Gastrointestinal nematode parasitism is a major concern for animal health and productivity. Studies at Rotomahana Research Station are evaluating the potential of genetic selection of sheep with increased resistance and/or tolerance to parasitism. Progeny testing of 35 sires in 1984 and 20 of these again during 1985 to investigate strain and sire variation, as well as repeatability in faecal egg counts (FEC), revealed an average heritability estimate of 0.34 }, issn = {1176-5283}, author = {Hohenboken WD and Muggli NE and Berggren-Thomas PL and Norman LM} } @conference {40001, title = {Inheritance of foot and jaw abnormalities in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {93-100}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {There are a total of some 710 000 winterfed sheep in Iceland, all of which are of the native Iceland breed. The organisation of the breeding work is in the hands of the Agricultural Society of Iceland. Sheep recording schemes have a long-standing tradition in Iceland. There are 140 local associations recording about 200 000 ewes. The most important traits in Icelandic sheep breeding are fecundity of ewes and weaning weight of lambs, but conformation and wool quantity are also considered. Level of productivity is high. The use of AI is of great importance in the sheep breeding work. Nearly all the selection of lambs for replacement is within flocks and selection work must be undertaken during a few weeks in the autumn when the sheep are taken from mountain grazing.}, issn = {1176-5283}, author = {Baker RL and Clarke JN and Harvey TG and Meyer HH} } @conference {40022, title = {Interpretation of objective measurements of wool by the manufacturer}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {189-198}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The implications for sheep breeding of objective measurement of the wool characteristics fibre diameter, medullation, length after carding, loose wool bulk, colour, and vegetable matter are discussed. For the purpose of this discussion breed differences are categorised into fine, medium, Romcross, higher-bulk, crimpy, lustrous, and medullated wool types}, issn = {1176-5283}, author = {Elliott KH} } @conference {40008, title = {Lambing date, ewe live weight and pasture mass effects on ewe and lamb performance during lactation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {129-132}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A series of 4 herbage allowance trials was conducted over 2 years with beef cattle on a well-drained site in Northland. Two trials were conducted in autumn/winter (April-July) and 2 in spring (October and November). Analysis of the data, for each seasonal period combined over the 2 years, showed large differences in the relationships between daily live- weight gain and herbage allowance between the 2 seasons. At the same allowance, beef cattle grew faster in spring than in autumn/winter. Relationships between allowance and daily live-weight gain were: Autumn/winter: LWG = 0.48-1.37* 0.65 allowance Spring: LWG = 1.09-2.82* 0.45 allowance These differences were not associated with differences in in vitro digestibility (70 to 78\% in all trials) or N concentrations. Allowances required for maintenance were lower in spring than in autumn/winter and potential growth rates in spring approximately double those in autumn.}, issn = {1176-5283}, author = {McCall DG and Smeaton DC and Wadams TK and Gibbison ML} } @conference {40028, title = {Live weights, fleece weights and wool characteristics of screened high fleece weight and randomly selected Romney ewe hoggets}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {219-224}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Trials between 1979 and 1984 with Angora or Saanen donors showed that synchronisation of oestrus with progesterone injections delayed oestrus compared with progestagen sponges and that this delay was associated with fewer follicles and increased egg recovery and fertilisation rates. Highest ovulation rates were achieved when FSH was injected instead of PMSG and when donors were Saanens rather than Angoras. Surgical egg recovery rates decreased in donors with prematurely regressing ovulations. The response of recipients (feral or Angora) to sponge treatment varied markedly between years. Recipient pregnancy rate and embryo survival both increased when recipients were surgically twinned rather than singled. The various trials have enabled the development of an effective transfer regime. This involves synchronising/superovulating donors with progesterone/FSH and twinning or tripleting of recipients. Under these conditions Angora and Saanen donors average respectively, 14.0 and 24.5 ovulations, 10.8 and 18.6 transferable embryos and 7.5 and 11.8 kids born to recipients.}, issn = {1176-5283}, author = {Hawker H and Littlejohn RP} } @conference {40009, title = {Management practices and productive performance on hill country sheep farms}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {133-138}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Beef cows in New Zealand are traditionally calved in late winter so that calves will be as big as possible for the weaner sales. This can create spring pasture supply problems and may contribute to poor reproductive performance in many beef herds. Early (11 August) and late (25 September) calving have been compared in 2 trials run on steep hill country. Comparisons were made in self- contained farmlets between June and February under 2 grazing strategies (set-stocking and rotational grazing). Later calving reduced interval to first oestrus by 16 d in both trials and increased pregnancy rates by 4 to 6\%. Late born calves grew at the same rate as early born calves in both trials (0.87 and 0.97 kg/d) and so were lighter at weaning at a fixed date. A rotational grazing strategy favoured cow performance, but set-stocking favoured calf weaning weight by 12 kg and 5 kg in the 2 trials. Later calving is likely to result in better reproductive performance in many hill country beef herds, but because calves will be lighter as weaners it would best suit systems where steers are currently retained and finished over 2 years or sold as store cattle at 18 months. The 18 month finishing policy will require earlier calving to maximise steer weight at sale time.}, issn = {1176-5283}, author = {Parker WJ and Townsley RJ} } @conference {40019, title = {A marker for red deer - wapiti hybrids}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {179-182}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The importance of the objective measurement of 6 wool properties, namely mean fibre diameter, medullation, fibre length after carding, colour, bulk and vegetable matter content is discussed. The necessity of accounting for all these properties when determining wool price differentials or the suitability of a wool lot or blend for a particular end-use is emphasised. An assessment is made of the manufacturing consequences of unit changes in each property along with end-use suitability, based on textile technology knowledge. This is supported by prices for New Zealand wool, analysed with account taken of availability, end-use and textile properties.}, issn = {1176-5283}, author = {Dratch PA} } @conference {39995, title = {New Zealand beef export carcass grading}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {63-66}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Somatic cell counts are used widely in the dairy industry to provide information on subclinical mastitis and milk quality. The value of this information is related to the benefits that can be obtained by using the somatic cell concentration to predict the presence of mastitis, and to the reduction in somatic cell count concentration that can be achieved by selective breeding. In this study the reduction in somatic cell concentration that can be achieved by culling and breeding is calculated from data collected under New Zealand conditions. Selection against logarithm (natural log) somatic cell concentration, without any emphasis on milk production, results in an annual rate of genetic change in log cell concentration of less than 0.6\%. This represents the maximum achievable rate of 10\% on the basis of their log cell concentration alone is predicted to reduce log cell count in the next lactation by 0.05 (cell concentration change of 20 000/ml).}, issn = {1176-5283}, author = {Woods EG and Fowke PJ and Bass JJ and Butler-Hogg BW} } @conference {39990, title = {Observations on the effect of litter size, pregnancy nutrition and fat genotype on ewe and foetal parameters}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {41-44}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Growth rates, carcass composition and management problems of "short scrotum" rams (made by elevating the testes to a position against the abdominal wall using rubber rings), wethers and entire male lambs were compared on a hill country property in northern Hawkes Bay. Of 3 groups of 65 Perendale lambs selected randomly at docking at about 4 weeks of age, 1 group was left entire, 1 was made short scrotum and the other was castrated. The lambs were weaned at about 10 weeks of age, separated from the main flock at about 14 weeks of age and thereafter kept as 1 flock until slaughter at 9 months of age. They were weighted every 6 weeks from 14 weeks of age. After the removal of 6 lambs from each group for detailed investigation at Massey University, the top 50 lambs from each group were slaughtered and their carcass characteristics recorded. Short scrotum rams showed management advantages over normal ram lambs. They were easier to handle, and avoided the works hygiene problem of dirty genitalia. Short scrotum rams had an overall live-weight advantage of 3kg over wether lambs. This was found not to be due to fat deposition, as short scrotum rams showed a significantly lower GR of 3.3mm, compared with normal rams (4.6mm) and wethers (6.2mm), as predicted by regression for lambs of 32kg live weight. There was no significant difference in carcass weight or dressing percentage between lambs of this live weight, although more normal rams and short scrotum rams fell into heavier grades than did the wether lambs. In detailed investigations on 6 lambs from each group, no differences were found in muscle:bone ratio or fat distribution between the groups. Short scrotum rams had very low fertility; 50 of 56 had no epididymal sperm reserves and 6 had extremely low sperm production. Most sperm from short scrotum rams were abnormal. Short scrotum rams had significantly lighter testes and epididymides than normal rams. Short scrotum rams had plasma LH levels intermediate to normal rams and wethers. Differences between entire and short scrotum rams in testosterone levels varied inconsistently}, issn = {1176-5283}, author = {Owens JL and Kyle B and Fennessy PF} } @conference {40003, title = {Organisation of sheep breeding in France}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {105-110}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Grazing yearling steers with ewes between November and March led to improved ewe and steer live-weight gains compared to grazing them in mobs by themselves. This occurred on both steep and easy land, and on each of 3 grazing pressures; residuals of either 1200, 1700 or 2300 kg DM/ha with pre-grazing masses 1200kg DM/ha greater than residuals. Ewe live-weight gains were 56, 67 and 82 g/d where sheep/cattle ratios were 100/0, 80/20 and 60/40, on a stock unit basis. Steer live-weight gains were 0.65, 0.55 and 0.51 kg/d for the 80/20, 60/40 and 0/100 sheep/cattle ratio treatments. Associated with improved ewe and steer performance under mixed grazing on steep country was a decrease in the area of pasture rejected at 40\% cattle stock units compared to 0\% and 20\% cattle (26\% v 32\%). On easy country, the amount of clover in the pasture increased by 5 and 19 percentage units at 40\% and 100\% cattle stock units respectively. The results suggested that between 20\% and 40\% cattle stock units in a mob may be needed to obtain high levels of ewe and steer live-weight gain in late spring-summer.}, issn = {1176-5283}, author = {Bodin L and Flamant JC and Elsen JM} } @conference {40033, title = {Ovarian follicular development in Booroola ewe lambs and in highly fecund Booroola ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {241-244}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Two hundred and thirty 5-year-old Romney ewes were synchronised with progestagen intravaginal sponges and injected with dexamethasone 142 or 143 days after the median mating day of the first and second cycles of oestrus. Seventy-one \% of the lambs were born 30 to 50 h after injection. The ewes were offered 2 pasture allowances for the last 6 weeks of pregnancy (approximately 6 and 1 kg DM/ewe/d). Lambs were vigour scored (1 to 10) and probed for rectal temperature and ewe lambs were cross-fostered as soon as possible after birth in order to obtain a 2 4 factorial design incorporating birth type (single and twin) rearing types (single and twin), pre-natal nutrition of dam (high and low allowance), and pre-natal nutrition of foster dam (high and low allowance). Lambs born from high allowance ewes had higher rectal temperatures at birth than those born from low allowance ewes, and female lambs had higher rectal temperatures than male lambs. Single-born lambs scored higher on vigour than those born as multiples. Increasing vigour was associated with increasing birth weight for all lambs, but increasing temperature was associated with increasing birth weight only for male lambs. There were no effects of pre-natal nutrition on lamb growth either through the dam or foster dam. The effect of birth type on lamb live weight was significant to 9 weeks of age whereas the effect of rearing type was significant to 33 weeks. There were no significant birth type x rearing type interactions at any age.}, issn = {1176-5283}, author = {McNatty KP and Lun S and Heath D and Hudson N and McDiarmid J and Ball K and Smith P and Henderson KM} } @conference {40038, title = {Perinatal lamb losses on a group of commercial sheep farms in Central Canterbury}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {263-264}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Voluntary consumption (VC) of wet feed and feed dry matter (DM) was measured indoors with sheep fed 3 ryegrass and 2 tall fescue cultivars at different stages of maturity. Increasing plant maturity, indicated by increasing proportion of stem and flowerhead and of neutral detergent fibre and cellulose contents, was associated with decreasing wet feed intakes. VC of wet feed was about 15\% higher with ryegrass cultivars than tall fescue cultivars. VC of feed DM was positively correlated (r = 0.89) with forage DM content at all stages of forage maturity and over a wide range of forage DM contents (12 - 25\% DM). VC of wet feed was not affected by changes in DM content so that with forage at the same stage of maturity DM intake was increased with an increase in forage DM content. Studies with rumen fistulated sheep showed 90\% of cells in eating boli are ruptured during 1 h incubation in rumen fluid in vitro or in vivo. Also VC of immature and mature perennial ryegrass was not affected when a balloon containing 1.5 l water was placed in the rumen whereas VC of chaffed lucerne hay was significantly depressed. It is concluded that VC of fresh forage is limited by a mechanism regulating intake of wet feed, not feed DM, and that DM content may be an important factor limiting nutrient intake.}, issn = {1176-5283}, author = {Gumbrell RC and Saville DJ} } @conference {39998, title = {Prediction of changes in somatic cell counts due to culling and selection}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {77-82}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Genetic variation of foot and jaw {\textquoteright}abnormalities{\textquoteright} in ewe hoggets and ewes has been studied with several breeds and strains at the Rotomahana Research Station. Foot and digit placement, foot roll, pastern angle and degree of hoof growth were scored for all 4 feet of each sheep at 9 months, 18 months and 5 years of age. Teeth occlusion, measured as the distance in mm (+ or -) between the front surface of the central incisors and the anterior edge of the upper pad, was recorded at 18 months and 5 years of age. Differences in incidence of foot abnormalities at 18 months of age among 2251 ewe hoggets representing 6 Romney strains and Coopworth or Border Leicester x Romney crosses, were significant for all traits except foot roll and digit placement. Border Leicester cross hoggets had a lower incidence of foot placement, pastern angle and hoof growth abnormalities than straightbred Romneys or Coopworth crosses. In a separate trial, 602 Booroola Merino first cross hoggets out of Romney and Perendale ewes had a significantly higher incidence of foot abnormalities than 480 straightbred Romney or Perendale ewe hoggets for all traits recorded at 18 months of age except pastern angle. There were only small differences among Romney strains and among breeds and crosses for teeth occlusion. Paternal half sib heritability estimates of foot traits recorded at 9 months of age were low (less than 0.11) and non-significant except for hoof growth (0.18 to 0.29). Similar heritability estimates for hoof growth were found in 189 month ewe hoggets (0.14 to 0.27) with low to moderate estimates for the other foot traits (0.02 to 0.17), and teeth occlusion (0.13 to 0.25). Heritability estimates were similar in 5- year-old-ewes for foot traits (0.03 to 0.20) but increased with age for teeth occlusion (0.36). Correlations between foot traits recorded at 18 months and 5 years of age were low (0.08 to 0.25), but were higher for teeth occlusion (0.49). Foot abnormalities and teeth occlusion were not found to have significant effects on either hogget growth, wool production or ewe reproduction, live weight or wool production. It is concluded that undue culling emphasis in ewes or rams on teeth or feet abnormalities is not warranted and may be counter productive.}, issn = {1176-5283}, author = {Smit H and Wickham BW} } @conference {39994, title = {Prediction of ewe mutton carcass composition from carcass weight, GR and C measurements, and the Hennessy grading probe}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {59-62}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Fourteen herd-years of data, comprising a total of 2169 records, were obtained from beef heifers involved in the Ruakura Genetics Section{\textquoteright}s long term breeding trials. The contributions of breed-cross, weight selection , herd year, birth date and age of dam, to variation in live weight, proportion exhibiting oestrus and proportion pregnant were studied. For heifers reaching first oestrus by about 15 months of age, means ages and weights at puberty were also calculated. Later-born calves were younger and lighter at puberty than average. Younger dams produced heifer offspring which reached puberty when older but lighter than average. Breed and location differences were greater for proportions of heifers expressing oestrus before joining than for proportions pregnant. At Goudies, the proportion achieving oestrus among Jersey x Angus heifers was 0.72, Friesian-cross 0.61, Hereford x Angus 0.47, Hereford 0.38 and Angus 0.25. Corresponding proportions diagnosed pregnant after 8 weeks of mating were 0.83, 0.93, 0.83, 0.78 and 0.73. Where there were major feed shortages over an extended period between 5 and 15 months of age, live weights and pubertal age were more affected than pubertal weight. In contrast, long term weight selection increased pubertal weight by 11\%, while pubertal age was little changed. Preliminary estimates of heritability for pubertal age and weight were 0.31}, issn = {1176-5283}, author = {Kirton AH and Feist CL and Duganzich DM} } @conference {40010, title = {Preliminary investigation into factors affecting lamb growth from birth to weaning on Taranaki hill country}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {139-144}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The aim of the present study was to examine the influence of the ram on plasma FSH concentrations in progesterone-primed Romney ewes which were: (1) anoestrous; (2) devoid of ovaries; (3) or anoestrous but induced to ovulate by a pulsatile injection regimen of luteinising hormone (LH). The results showed that there was an abrupt fall in the mean FSH levels in anoestrous or LH-pulsed ewes at 1 hour after ram introduction and that this level of suppression (~40\%) was maintained for ~22 hours in anoestrous ewes and for 12 hours in LH-pulsed ewes. Also, an FSH reduction (~20\%) was observed in the ovariectomised ewes. In the anoestrous ewes, the FSH changes were observed without any associated oestrous or ovulatory behaviour. In the LH-pulsed group, all ewes showed oestrus and 75\% produced normal corpora lutea. Collectively, the evidence suggests that when attempts are made to achieve fertile matings in hormone-treated anoestrous ewes, there may be advantages in delaying ram introduction until ~24 hours after progesterone withdrawal.}, issn = {1176-5283}, author = {Thomson NA and Mace MJ and Wright LA and Bishell SM} } @conference {39991, title = {Progeny testing for lean meat production in the Poll Dorset breed}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {45-48}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The composition of the dressed carcasses of 54 mixed-breed ewes was predicted from their hot carcass weight (HCW), measurements C and GR, and carcass wall thickness taken on the left (GPL) and right (GPR) sides 13 cm from the mid-line between the 11th and 12th ribs with an electronic Hennessy grading probe. The right side of each carcass was dissected into fat, muscle and bone. Mean HCW was 25.4 kg, GR was 16.9 mm, C was 6.6 mm, GPL was 22.1 mm, GPR was 22.7 mm, dissectible fat was 32.4\%, muscle was 52.4\% and bone was 14.1\%. Of the variation in carcass fat \%, GPR accounted for 74\% and GR for 78\%. When combined with HCW, GPR accounted for 77\% and Gr for 80\%. This last value was not further increased by adding more variables. GPR accounted for 67\% of the variation in carcass muscle \% and GR for 68\% of this variation. When combined with HCW these values increased to 71\% and 73\% respectively and were not further increased by adding more variables. GPR and GR were also the best predictors of percentage bone.}, issn = {1176-5283}, author = {Barton RA and Pratt RM and Rae AL} } @conference {40013, title = {Ram-induced inhibition of plasma follicle-stimulating hormone (FSH) concentrations in anoestrous Romney ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {153-156}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A major constraint on the profitability of using {\textquoteright}Fecundin(r){\textquoteright} is the cost of treatment and one approach to this problem is to reduce the dose rate. In 1984 Coopworth ewes were allocated to 3 groups. One group was untreated (control) while the other 2 groups were injected twice with Fecundin. One treated group received a full dose (2ml) each time while the other group received a half dose (1ml) on both occasions. In 1985 the same ewes were roboosted with Fecundin(r). Control ewes remained untreated while ewes from each group in 1984 were boosted with either a half or full dose. In the first year, both immunised groups showed a substantial increase in ovulation rate over controls (2.45 full, 2.20 half and 1.86 control). The higher ovulation rate of full dose compared to half dose ewes did not result in more lambs born or weaned (lambs born/ewes joined were 1.68 full, 1.65 half and 1.35 control). In 1985 all 4 treatment groups had a higher ovulation rate (2.43) than the control (2.03 and there were no difference between immunisation treatments. A similar patter was seen in lambs born. Thus the cost of treatment can be halved by using a 1 ml dose of Fecundin(r) without a drop in the additional performance obtained.}, issn = {1176-5283}, author = {McNatty KP and Hudson N and Gibb M and Ball K and Morrison L} } @conference {40026, title = {Rationalised classing of fine wools}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {209-213}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Oestrus synchronisation in hoggets was compared using either polyurethane sponges containing progestagen or 9 mm diameter silicone elastomer CIDRs (controlled internal drug releasers) in 600 hoggets in 3 trials. CIDRs and sponges were removed after 12 days in late May and 200 IU PMSG given to hoggets in 2 of the trials. Hoggets in the third trial received 0 or 300 IU PMSG. Half of the hoggets were shorn 1 month prior to the 4-day joining with entire rams. The loss rate of CIDRs and sponges was low (2\%). No hoggets mated in the first 24 hours after removal and most matings occurred during the second day. During the peak of mating, more CIDR-treated hoggets appeared to mate in 2 trials, but fewer in the third (28 v 44\% P<0.01). By the end of the entire joining, there was little difference in total mated. Treatment with CIDRs or sponges did not affect ovarian activity. Pregnancy rates were unaffected by method of synchronisation in 2 trials and improved by CIDRs in the third (38 v 20\% P<0.05). Shearing generally had no effect on reproductive performance. PMSG improve oestrous and ovarian activity, but did not affect pregnancy rate. CIDRs were an effective substitute for sponges in achieving synchronised pregnancies in hoggets. Low pregnancy rates limited the ability to fully capitalise on the benefits of synchronisation.}, issn = {1176-5283}, author = {Andrews RN and Hawker H} } @conference {40020, title = {Reasons and strategy for the introduction of objective measurement of wool}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {183-186}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Management factors under the direct control of the wool grower which influence objectively measured wool characteristics are breed, age, sex, level of feeding, frequency and time of shearing, breeding status and control of disease. Choice of breed has the greatest overall effect on wool type and resultant price level. Within the prevailing price structure wool returns for each breed type are more influenced by quantity than shifts in objective characteristics because of short term management decisions. This has resulted in considerable emphasis by growers, advisers and researchers on maximising overall wool production. Of the flexible management decisions, level of feeding and frequency and time of shearing have the greatest effect on objective fleece characteristics important in manufacture. Objective measurement will provide an objective basis for payments to growers through a better understanding of the technical effects of changes in measured characteristics. This will result in clearer price signals for differential changes in fleece characteristics and improved product specification ensuring the long term viability of wool production.}, issn = {1176-5283}, author = {Simpson WS} } @conference {40002, title = {Repeatability of reproductive performance following active immunisation of ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {101-104}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The New Zealand sheep industry has been supported by a national sheep recording scheme, Sheeplan, for nearly 20 years. Sheeplan is directed towards genetic improvement of the national sheep flock. Its personnel have recently prepared a plan for future development which aims to extend the scope of the scheme, the accuracy of selection decisions made and the flexibility and efficiency of the recording service. It is proposed that the improved scheme be developed under Sheeplan{\textquoteright}s existing organisation as a centralised recording scheme and that restructuring of the data storage and data processing system be undertaken to enable Sheeplan to develop the following specific areas: improved adjustments for non-genetic factors; greater breeding value accuracy; development of across-flock relationships among animals; extension of the Sheeplan database; establishment of an industry-wide database; improved operational efficiency; accommodation of electronic developments for data collection and transmission; provision of opportunities for data analysis; and improve documentation of the scheme. The estimated financial benefit of implementing the plan is a doubling of the annual return to the sheep industry, from $9.6 million from the current Sheeplan to $19.7 million. This is achieved through a 40\% increase in accuracy of selection decisions; a 10\% increase in Sheeplan membership; and a 30\% increase in effective use of Sheeplan records.}, issn = {1176-5283}, author = {Clarke JN and Smith JF and Johnson DL} } @conference {40004, title = {Sheep breeding organisation and recording in Iceland}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {111-116}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Mixed grazing experiments require decisions on the equivalence or interchangeability of grazing species. Often equivalence is based on an assumption of the relative feed intake of the species concerned. Another approach is to equate the species in terms of the effect they have on the pasture e.g. removal of herbage mass. In this experiment the species response to given sward conditions was investigated by controlling the rate of disappearance of herbage mass so that the equivalence of the species in terms of intake was derived rather than assumed. An autumn/winter ryegrass/white clover sward was grazed separately by growing castrate cattle (320kg), sheep (28kg) and goats (17kg). Plot area and animal numbers were adjusted as necessary (on a daily basis) to achieve the same rate of dry matter (DM) disappearance for each species. The 2 rates of DM disappearance for each species were achieved over 4 and 10 days and were 522 (}, issn = {1176-5283}, author = {Johmundsson JV} } @conference {39983, title = {The society - about attitudes and perspectives}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {1-4}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {One alternative to control of gastrointestinal nematode parasitism with anthelmintics may lie in genetic selection for resistance to infection and/or disease. Heritabilities for faecal egg count suggest that good selection responses can be achieved with Romney sires. Research must now identify markers that will accurately predict resistant and susceptible animals. To do this successfully, mechanisms associated with immune-competence, - tolerance and -expulsion and host resistance to these nematodes must be elucidated more fully. This review examines local and systemic humoral and cell-mediated immunities to some of the GI nematode parasites infecting sheep, goats and cattle, with emphasis to sheep. Additional literature is presented identifying some of the factors that may modify any responses; factors such as host nutrition, hormonal and reproductive status and genetics. The overwhelming conclusion must be that significant large voids exist in our understanding of the processes of immunity exerted by domestic stock to combat infection with nematode helminths. Furthermore much latitude has been taken describing and interpreting observations since many are postulated from studies involving laboratory host parasite models.}, issn = {1176-5283}, author = {Sykes AR} } @conference {39997, title = {Some genetic and non-genetic effects on the first oestrus and pregnancy rate of beef heifers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {71-76}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Hogget fleece weight (HFW) (n=10376) and live weight (HLW) records (n=5930) from a highly fecund Coopworth flock were analysed by least squares methods to obtain estimates of environmental effects, heritabilities and genetic and phenotypic correlations. Single-born ewe hoggets were 2.7kg heavier than twins and 4.0kg heavier than triplets, and HFW differences were 0.07kg and 0.13kg respectively. Single-born ram hoggets were 2.9kg heavier than twins and 4.3kg heavier than triplets, HFW differences being 0.04kg and 0.10kg, respectively. Ewe hoggets reared by 3, 4 and 5 year old dams were 0.7, 1.2 and 1.4kg heavier than those reared by 2 year old dams, and the corresponding estimates for ram hoggets were 0.6, 1.8 and 1.3kg. Dam age did not significantly affect HFW; linear regression coefficients of the traits on age were 0.003kgd-1 (ewes) and 0.006kgd (rams) for HFW, and 0.04kgd-1 and 0.08 kgd-1 for HLW. The regression of HFW and HLW was 0.02kgkg-1. Heritability estimates (from paternal half-sib analyses) for HFW were 0.52}, issn = {1176-5283}, author = {Morris CA and Baker RL and Bennett GL} } @conference {39993, title = {A study of short scrotum, castrated and entire ram lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {55-58}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Evidence of genetic improvement in the Department of Lands and Survey{\textquoteright}s Angus Breeding Scheme (ABS) was examined. Data from the ABS project and from the pilot Angus Sire Reference Scheme (ASRS) were used to estimate genetic trend in weaning weight and yearling weight in the ABS nucleus by regressing sire group values on year of birth. Estimated genetic improvement in weaning and yearling weight used the ABS data were 1.6}, issn = {1176-5283}, author = {Probert AD and Davies AS} } @conference {40034, title = {Viability of frozen sheep embryos and semen imported from Europe}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {46}, year = {1986}, month = {Jan}, pages = {245-250}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied}, issn = {1176-5283}, author = {Tervit HR and Baker RL and Hoff-Jorgenson R and Lintukangas S and MacDiarmid SC and Rainio V} } @conference {39947, title = {The application of a lean growth index in ram breeding flocks}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {77-80}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Carcass composition is determined by the relative partitioning of metabolisable energy intake among protein, fat and heat. Protein deposition is the net difference between rates of protein synthesis and protein degradation in tissues; synthesis and degradation proceeding at rates several times that of deposition. Relatively small changes in rates of protein synthesis or degradation may result in relatively large changes in deposition. The energy cost of protein synthesis may reduce energy available for fat deposition. The manipulation of carcass fat content may be more readily achieved by increasing lean growth than reducing fat deposition. Development of accurate methods for measuring protein synthesis should facilitate understanding of the mechanisms by which lean animals are grown and the selection of growth promotants useful in the production of leaner carcasses.}, issn = {1176-5283}, author = {Dodd CJ and Bennett GL and Purchas RW} } @conference {39940, title = {Are rams necessary for the stimulation of anoestrous ewes with oestrous ewes?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {49-50}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A study in 1980 showed that rams from a high prolificacy flock (Waihora) were more successful than rams from a low prolificacy flock (Whatawhata fertility control) in fertilising ewes by copulation. In this study translational swimming speeds of ram sperm in caprogen at 39}, issn = {1176-5283}, author = {Knight TW} } @conference {39933, title = {Blood metabolites and infertility in dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {17-20}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Kallikrein-like enzyme (KE) activity has been detected in bovine saliva from the front of the mouth and from the cannulated mandibular gland. The maximal activity (39 mUnits ml-1) was present in secretions from the mandibular gland of cows stimulated with carbachol (parasympathomimetic). A lower activity (24 mUnits m-1) was obtained under isoprenaline (sympathomimetic) combined with carbachol stimulation. No detectable KE activity was present in parotid gland secretions. When tested for vasodilator activity in sheep, all samples tested were positive, but the greatest response was mandibular secretions collected under carbachol stimulation. Using purified salivary proteins, it was demonstrated that the KE activity was associated with bands 7 and 8, major proteins secreted by the mandibular gland.}, issn = {1176-5283}, author = {Wilson GF and MacKenzie DDS and Holmes CW} } @conference {39959, title = {Body energy changes and metabolisable energy requirements in growing and adult sheep at pasture}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {129-132}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The growth of lambs, herbage mass and pasture composition (pre- and post-grazing), were monitored from January to June 1984 on 3 farms carrying 12 to 13 su/ha in the Taranaki hill country. Live weight was measured monthly on a random 5\% of each flock. Additional animals were treated with cobalt (vitamin B12), selenium or both to identify possible deficiencies of these elements. A {\textquoteright}preventative{\textquoteright} drenching programme was adopted on each farm to control gastro-intestinal worms. Mean daily live-weight gain was low (49 to 74 g/lamb) and did not improve significantly as a result of selenium or vitamin B12 treatment. Faecal egg counts indicating significant worm burdens were recorded on 2 of the farms in autumn despite regular drenching. Pasture before grazing were characterised by a high herbage mass (>3000 kg DM/ha) and a low green leaf content (50 to 60\%). Apparent utilisation of DM at a single grazing was low (14 to 24\%) but utilisation of green leaf was higher (28 to 43\%). Green stem and dead herbage were not utilised. Although no factor was clearly defined as limiting animal performance, it is felt that improvements could be made by more intensive grazing (so that young stock are presented with lower herbage mass of higher green leaf content) and by adopting a more effective drenching programme.}, issn = {1176-5283}, author = {Geenty KG} } @conference {39946, title = {The calculation of a simple lean-growth index for young sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {73-76}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Display life of frozen lamb chops was unaffected by breed or sex. Chops shrink-wrapped in oxygen permeable film had a longer display life than those vacuum packaged in a film of low oxygen permeability. Chops cut from frozen loins, then packaged had a significantly longer display life than chops cut from chilled loins, packaged, and then frozen. Ram lamb chops had significantly higher pH values than those from wethers and ewes. Chops from Romney-cross lambs had lower pH values than those from Coopworth-cross and Perendale-cross lambs. Meat pH decreased slightly but significantly during storage.}, issn = {1176-5283}, author = {Purchas RW and Bennett GL and Dodd CJ} } @conference {39931, title = {Comparative dairy production of Jersey and Friesians}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {7-12}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Reasons for a temporary infertility syndrome in pasture-fed dairy cows were sought. Low submission and conception rates in 35 mature Friesians (either of high or low breeding index) were associated with low plasma albumin and glucose concentrations at the commencement of mating and poor body condition prior to calving. Discriminant function analysis indicated that albumin concentration was the most important variable in the allocation of cows to "fertility" groupings. Breeding index and level of milk production were relatively unimportant. A disturbance in protein metabolism was implicated as the cause of the infertility syndrome. A concentrate supplement containing 19\% crude protein, fed to monozygous twin cows at 1.4 kg/d for 3 weeks prior to mating led to a marked improvement in conception rate.}, issn = {1176-5283}, author = {Bryant AM and Cook MAS and MacDonald KA} } @conference {39954, title = {Comparative intake of digestible organic matter and water by sheep and goats}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {107-112}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The diurnal pattern of grazing and of rumen fill was studied to assess whether the initiation and cessation of eating were associated with any particular level of rumen fill. Four wethers fitted with large rumen cannulae grazed Huia white clover or Matua prairie grass for 14 to 21 days. Animals grazed longer on the prairie grass than on the white clover (8.9 v 5.8 h). Major grazing periods were evident in the morning and afternoon, although the animals generally spent more of each hour in razing during the afternoon. Rumen fill (volume, wet weight and dry weight) showed diurnal patterns of change similar to the grazing pattern. The maximum level of rumen fill (9.5 and 7.0 g DM/kg live weight (W) on grass and clover respectively) was observed at the end of the afternoon grazing period and the minimum at 0900 h on the grass (5.2 g DM/kg W) and at 1300 h on the clover (3.9 g DM/kg W). The implication of these results is that the intake of these roughages is less than that which is physically possible if the animal ate consistently to its maximum fill.}, issn = {1176-5283}, author = {Alam MR and Poppi DP and Sykes AR} } @conference {39976, title = {Contract Summary}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {197}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A predictive test for susceptibility to fleece yellowing, which has a high heritability (0.5), is described. In a flock of Corriedale ewes 2 lines, selected entirely on the basis of the predictive test, demonstrated predicted levels of fleece yellowness when conditions promoted high levels of discoloration. Assessed greasy and measured scoured wool yellowness were not highly correlated. The yellowness value of scoured wool of highly resistant (HR) fleeces was always low; that of highly susceptible (HS) fleeces was variable and often high. The yellowness value of HS fleeces increased on storage of greasy fleeces. There was a negative correlation between yield and susceptibility, which was not strong enough to use for predictive purposes. HR and HS Corriedale ewes, thoroughly washed and then housed to eliminate weather effects, showed striking differences in yield \% (83 v 61), wax \% (16 v 25) and suint \% (5 v 29) respectively. Pilocarpine hydrochloride was administered to the housed sheep to determine whether fleece yellowing and related faults were caused by excessive sweating. Results are variable.}, issn = {1176-5283}, author = {Smith JF} } @conference {39965, title = {Diagnosis of foetal number in prolific sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {155-158}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Two experiments were designed to estimate the effects of paddock contour on lamb mortality between 1 and 4 d of age (Expt 1) and 5 and 28 d of age (Expt 2). In Expt 1, 153 lambs born to 2-year-old ewes lambing in easy contoured paddocks (<20}, issn = {1176-5283}, author = {Owens JL and Armstrong JR} } @conference {39968, title = {Differences among and within crossbred beef cow groups in body condition and live weight}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {167-170}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {In April and May 1983 60 Merino x Romney ewes of known Booroola genotype (30 F+, 30++) were immunised against androstenedione. An equal number of contemporary ewes of the same breed type and Booroola genotype were run together as an untreated control. Ewes were joined with vasectomised rams and ovulation rates were measure 4 weeks after the booster injection and thereafter at 3 successive 17-day intervals. The immunised F+ ewes showed an initial ovulation rate response of 1.62 compared with F+ controls and the response had decreased to 0.17 at the fourth observation 51 days later. The immunised ++ ewes showed an initial response in ovulation rate of 0.29 which increased to 0.61 at the second observation and decreased to 0.12 at the fourth observation. The experiment was repeated with the same sheep in 1984. Half of the ewes immunised in 1983 were given a booster injection in December 1983 (early group) and the other half were boosted in May 1984 (late group). Control ewes remained untreated. The early F+ immunised ewes had an ovulation rate response of 1.93 in February and 6 months later in August the response was still 0.90. The early ++ immunised had an initial response of 0.33 which increased to 0.40 at the second observation and decreased to 0.9 in August. Late F+ and ++ immunised ewes had initial responses of 0.71 and 0.38 which declined to 0.52 and 0.05 respectively 51 days later. These results all show a consistently higher response to immunisation in F+ ewes. The F+ ewes immunised in December before the onset of the breeding season showed the highest initial response and 8 months after the booster vaccination a significant response was still evident. F+ ewes immunised during the breeding season (booster injection in May) showed a lower initial response and a lower subsequent response than F+ ewes immunised before the breeding season. The duration of the response could not be determined in these ewes because of the short period from boosting until the end of the season.}, issn = {1176-5283}, author = {Morris CA and Cullen NG and Carson PA and Morley GA} } @conference {39948, title = {Display life of frozen lamb chops. Effect of breed, sex, packaging film and temperature at packaging}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {81-84}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Effects of shearing and restricted feeding on the weight and leanness of lamb carcasses were measured in 3 experiments. Changes in fat measurements were parallel to and consistent with changes in carcase weight except where shearing and restricted feeding were combined. The 2 treatments together resulted in carcasses about 1 mm GR leaner than expected for their weight. Shearing following by mild underfeeding was more effective than either procedure alone in reducing fat cover and may increase the market value of overfat lambs.}, issn = {1176-5283}, author = {Moore VJ and Duganzich DM} } @conference {39956, title = {Diurnal patterns of rumen fill in grazing sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {117-120}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Weaned lambs grazed areas of native tussock oversown with either lotus or a mixture of white and red clover for 2 consecutive 4-week periods in each of 2 years. The lambs selectively grazed introduced legume in the clover plots but not in the lotus plots. At herbage allowances at or below 2 kg DM/animal/d, there were no differences in live-weight gain (LWG) between lambs grazing areas oversown with either lotus or clover. At high allowances, LWG tended to be lower during the initial 4 weeks of grazing lotus (60 to 114 g/d) and to then increase to comparable values for lambs grazing areas oversown with clovers (140 g/d). Any depression of LWG could be minimised by "conditioning" lambs to lotus, and by management of companion grasses to keep them in the vegetative state. It was concluded that the initial period of lower LWG on lotus would not be a drawback if lotus was used as a maintenance-type feed for ewes in summer/autumn.}, issn = {1176-5283}, author = {Thomson BC and Cruickshank GJ and Poppi DP and Sykes AR} } @conference {39975, title = {Does immunisation pay?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {193-196}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Selection objectives for wool characteristics are usually set by analysing past prices, considering the results of processing trials and trying to predict future changes. Deficiencies in the information for setting selection objectives were, until recently, the main problems in calculating selection weightings. The situation has largely been rectified and the major problem now is in translating the object into index weightings. Variation in the genetic parameters causes great variation in the indices and there are doubts about the accuracy of the estimates of genetic and environmental correlations available. Recently calculated objectives place more emphasis on fleece weight than earlier formulations. Bulk, colour, length, resistance to cotting and soundness (staple strength) seem sufficiently important to include in the objective but indexes calculated using present genetic parameters usually place little weight on them. The result is that the extra gains from including colour, cotting and soundness in the index will probably not compensate for the work involved. However inclusion of resistance to cotting and soundness in the objective leads to more attention to fleece weight in the index. Foreseeable changes in market conditions seem unlikely to change these conclusions but a different set of correlations or cost/benefit calculations might lead to modifications.}, issn = {1176-5283}, author = {Scobie GM and Bircham JS} } @conference {39972, title = {Effect of ewe live weight on the level of response to steroid immunisation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {184-187}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Immunisation has implications for genetic improvement programmes by influencing the intensity of selection, the amount and nature of genetic variation able to be exploited by selection, the accuracy of the selection process or by adding flexibility to animal husbandry that might otherwise be the objective of dynamic crossbreeding strategies. Since immunisation changes the reproductive rate of a flock there are consequential effects on the intensity of selection that is possible. Improving the effective lambing percentage from 120\% to 140\% can increase the intensity of selection of female replacements by about 19\%. The improvement is less on the male side, the combined effect on genetic improvement in a ram-breeding flock of 400 ewes being about 6\%. Alteration to the balance of physiological events may even serve to display genetic variation not otherwise available for selection. Good evidence is available that natural ovulation rate is a useful selection criterion for improvement in lamb production, but there is no direct evidence on the value of selection following immunisation of ewes to steroid hormones controlling reproduction. Indirect evidence for sheep that litter size responses to immunisation are essentially additive with respect to the effects of age of ewe, flushing treatment, breed and strain differences, suggests no major antagonisms with natural ovulation rate. Indirect evidence from mice is not so comforting - Land and Falconer{\textquoteright}s selection experiment for natural and PMS-induced ovulation rate gave an estimate of only 0.33 for the genetic correlation between these two traits, suggesting that they were largely independent genetically. Regardless of the true genetic situation for sheep it seems important that recording programmes recognise and adjust for the different distributions of ovulation rate and litter size under natural v immunised circumstances.}, issn = {1176-5283}, author = {Smith JF and MacLean KS and McGowan LT and Potts IR} } @conference {39963, title = {Effect of herbage allowance on the productive performance of lactating and non-lactating hoggets}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {147-150}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Techniques of real time ultra sound (ADR 2130), Toshiba Sonolayer-L SAL 22A) and radiography (DSIR X-ray) were assessed to determine the accuracy of identifying ewes carrying 3 or more lambs. Ewes were scanned between 62 and 75 days of gestation with ultra-sound and between 110 and 124 days with X-ray. There were 94.2\% (ultra- sound) and 96.2\% (X-ray) of ewes predicted to be carrying 3 or more lambs that actually lambed with 3 or more lambs. However, 21.1\% (ultra-sound) and 8.4\% (X-ray) of ewes which lambed with 3 or more lambs were predicted to lamb with<3 lambs. Because ultra-sonic diagnosis is carried out at an earlier stage of gestation it gives greater flexibility to apply nutritional management to ewes carrying 3 or more lambs in order to sustain foetal growth in these high litter sizes.}, issn = {1176-5283}, author = {McEwan JC and Mathieson CD and Hawker H} } @conference {39953, title = {The effect of level of milk intake on growth rate and herbage intake of Friesian bull calves of high and low breeding index}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {103-106}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Protein (NAN) flow to the small intestine was measured in early- weaning ram lambs grazing pure swards of white clover (W), lucerne (L), ryegrass (R) and prairie grass (P) at high allowances. Lambs were weaned at 6 weeks of age and measurements made at 8 and 12 weeks of age. Live-weight gain (LWG) measured over 6 weeks after weaning was higher for lambs grazing on legumes (308 }, issn = {1176-5283}, author = {Wang X-J and Brookes IM and Wilson GF} } @conference {39981, title = {Effect of post-weaning and post-mating/post-weaning shearing on ewe performance}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {221-224}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied}, issn = {1176-5283}, author = {Sumner RMW and Willoughby LD} } @conference {39970, title = {Effect of season of steroid immunisation and Booroola genotype on the level of duration of response in ovulation rate of ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {178-180}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A trial was conducted in 1984 to examine the effect of live weight on response to immunisation in 3 groups of 200 Coopworth ewes differentially fed from weaning in December to reach 3 live weights in March (40, 50 and 60 kg). Half of the ewes in each group were immunised with Fecundin(r) and further subdivided into 2 levels of nutrition (*1.5 v 3.4 kg DM/ewe/d) for 4 weeks prior to a synchronised mating. Ovulation rate (OR); percent ewes lambing to first cycle (CR); lambs born per ewe lambing (LB/EL); percentage ova wastage (PRMO); and lambs born per ewe joi9ned (LB/EJ) were determined. Immunisation had a significant effect on all parameters (OR= +0.56; CR= -7.6\%; LB/EL= +0.37, PFMO +10.1\%; LB/EJ= 0.25). Ewe mating weight significantly increased OR (+0.37), CR (+19.5\%), LB/EL (+0.25) and LB/EJ (+0.34) but did not significantly influence ova wastage. Premating nutrition significantly increased OR (+0.23), LB/EL (+0.09) and PFMO (+8.9\%), but not LB/EJ. The regressions on mean group mating weight of OR and LB/EL in first cycle showed similar slopes for the immunised and control ewes. Nutritionally induced differences in ewe mating weight therefore did not influence these responses to immunisation. The response to LB/EJ was greater in the heavier ewes and reflected the effects of live weight on conception rate and embryonic loss.}, issn = {1176-5283}, author = {Davis GH and Crosbie SF and Smith JF} } @conference {39967, title = {Effect of slope on lamb mortality}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {163-166}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {In the 10 years since it was observed that immunisation of ewes against steroid hormones resulted in an increased ovulation rate, research has provided some understanding of the mechanism of immunoneutralisation and of the factors which influence or modify the immunological and physiological response of ewes. It has also led to the development of a commercial vaccine. The mechanism of action is still uncertain although several changes in the endocrine balance of the ewe may be involved. Active immunisation against a number of steroids has been shown to increase ovulation rate and with passive immunisation, a mixture of steroid antibodies produced the best result. One possible mechanism via a reduced negative feedback on the pituitary and increased gonadotrophin release has been recorded. Effects at the ovarian level influencing follicular atresia must be also considered. The initial attempts at the practical application of this technology were unsuccessful. Although ovulation rates were increased, fewer lambs were born per ewe joined due to problems of anoestrus and anovulation. From these data the relationship between antibody titre and response was established and alterations to the composition of the antigen and treatment schedule were developed to modify the antibody response. Factors such as ewe age, level of nutrition and breed had little effect on the response. The response to changes in nutrition and live weight appear to be additive to those of immunisation, as is the response to exogenous gonadotrophins (PMSG). The timing of treatment relative to mating appears to have some effect, with intervals of less than 21 days reducing the lambing response through a high proportion of barren ewes. However there has been considerable variation in the final response indicating a major effect of early embryonic mortality. Lamb birth rank distribution has been within the predicted range and been seen mainly as an increase in twins with some higher order multiples. The mortality of lambs from treated ewes has been similar to that of lambs of the same birth rank from untreated ewes. The growth and reproductive performance of the progeny from treated ewes has been unaffected.}, issn = {1176-5283}, author = {McMillan WH and Knight TW} } @conference {39971, title = {Effect of steroid immunisation in the performance of 3 breeds of sheep under hill country conditions}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {181-183}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Forty Romney hoggets were immunised against oestrone during March. A similar number served as untreated controls. Half of each group was treated with progestagen sponges to induce oestrus. Their ovulation rates were determined 7 day after sponge withdrawal and in mated hoggets within 14 days of first oestrus. Half of the immunised ewes were boosted as 2- and 4-tooths, the balance receiving only a 4-tooth booster. Half of the untreated controls were first immunised as 4-tooths. Ovulation and lambing rates were recorded. Immunisation increased hogget multiple ovulation rates by 50\%. Unboosted 2-tooth ewes had multiple birth rates and numbers of lambs born similar to untreated controls. Boosted 2-tooths had more multiple ovulations (37\%), ewes lambing multiples (28\%) and lambs born (28\%) than control ewes. The ovulation rate of 4-tooth ewes was 2.24. Untreated control ewes had the lowest proportion of triple ovulating ewes (11\%), with first treated 4-tooths and 4-tooths missing their 2-tooth booster intermediate (22\%) and annually boosted 4-tooths highest (38\%). Control 4-tooths lambed fewest multiples (53\%), first treated 4-tooths were intermediate (63\%) and 4-tooths missing their 2-tooth booster and annually boosted 4-tooths highest (75\%). However, differences in 4- tooth ovulation and lambing responses were not significant. The limited data demonstrate that annual immunisation against oestrone can increase ovulation and lambing rates. Ewes missing an annual booster perform at levels similar to untreated control. Furthermore, the immunomemory system for oestrone appears to last for at least 24 months since the ewes gave birth to 189\% of lambs compared to 194\% in annually boosted ewes and 159\% in untreated controls.}, issn = {1176-5283}, author = {Knight TW and Smith JF and Sumner RMW} } @conference {39960, title = {Effects of facial eczema on ewe reproduction and ewe and lamb live weights}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {133-136}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Because preliminary evidence indicated that shearing Romney ewe hoggets in early October increased wool growth in spring-summer but had little effect on live-weight gain, an experiment was designed to quantify the feed intake, live-weight gain and wool growth of shorn and woolly hoggets in spring-summer. The design was a 2 x 3 x 2 factorial, i.e. shorn v woolly hoggets (shorn at 4, 12 and 17 months of age v shorn at 4 and 17 months) x 3 herbage allowances (1.6, 3.2 or 4.8 kg total DM/hogget/d) x 2 replicates x 2 years. The 12 mobs, each comprising 15 hoggets, were shifted twice weekly for 18 weeks, with residual DM measured and intakes estimated at each shift. Live-weight gain (LWG) and wool growth were measured every 6 weeks from early October until mid February. There were no significant differences between the shorn and woolly hoggets in residual DM (and therefore in utilisation and intake) or in LWG. The shorn hoggets grew 1 g/d more clean wool during spring-summer, i.e. a total advantage of 0.2 kg greasy. LWG and wool growth increased curvilinearly with allowance. LWG{\textquoteright}s were greatest in October-November, while wool growth was greatest in January-February. Five shorn and 4 woolly hoggets were penned outdoors in close proximity to the grazing experiment and fed a pelleted diet ad lib. for the first 6 weeks after shearing in early October. Relative to the woolly hoggets the short hoggets ate 20\% less in week 1, the same amount in week 2, and increasingly more from weeks 3 to 6 (30\% difference in week 6). The results indicate that shearing in spring does not lead to significantly higher feed intakes nor to greater LWG{\textquoteright}s, although it does results in a modest increase in wool growth.}, issn = {1176-5283}, author = {Smeaton DC and Hockey H-UP and Towers NR} } @conference {39932, title = {Effects of level of feeding at different times of the year on milk production by Friesian cows of high or low genetic merit}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {13-16}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Udder volume (post milking) was determined in high and low breeding index (HBI;LBI) Jersey and Friesian cows. The difference in milk production of HBI and LBI Jersey herds (2 to 4 litres/day) was entirely attributable to difference in udder volume. This difference was generated during late pregnancy. Udder volume declined during lactation; 35 to 40\% of udder volume at calving being lost by 20 weeks of lactation. There was no difference in udder volume between BHI and LBI Friesian cows measured at peak and in late lactation. Differences in production between these herds were due to increased udder productivity in the HBI animals (HBI, 2.0 litres/litre tissue/d; LBI 1.8 litres/litres tissue/d). Udder productivity in Friesians was 25\% greater than in Jersey cows at peak and in late lactation. Milk yield and udder volume were significantly correlated (P<0.05) in Friesian and Jersey cows at all stages of lactation. Genetic selection of Friesian and Jersey cows has resulted in more productive animals in both breeds but through differing physiological mechanisms.}, issn = {1176-5283}, author = {Holmes CW and Brookes IM and Ngarmsak S and Mitchell KD and Davey AWF} } @conference {39982, title = {Effects of level of nutrition in winter and summer on the wool growth of Romney and Perendale ewes with a history of high or low winter wool growth}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {225-228}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The active immune system involves phagocytic, cell mediated and humoral processes plus complement proteins, all interacting to protect the individual from pathogenic organisms. Passive immunity is acquired by new-born ungulates by ingestion of immunoglobulins from colostrum. Research in laboratory animals has established that peak antibody synthesis following challenge with a foreign antigen responds readily to directional selection. The increased titre frequently results in enhanced resistance to some diseases but enhanced susceptibility to others. Oregon State University research has produced conflicting results as to the heritability of the ability of new-born calves and lambs to acquire and absorb colostral immunoglobulins and as to the heritability of this passive immunity considered as a trait of the dam. Significant differences among breeds, selection lines and strains did exist for level of colostral immunoglobulins, and low levels (and, in one experiment, high levels as well) were associated with lower neonatal survival. In cattle, there was little evidence that either active immune response or level of complement protein C3 was heritable; but in ewes, the antibody titre to a challenge antigen was moderately to highly heritable. The authors speculate that stabilising selection for immune system traits might be most effective to improve generalised disease resistance and overall livestock production efficiency.}, issn = {1176-5283}, author = {Hawker H and Crosbie SF} } @conference {39939, title = {The effects of season on reproduction in beef cows - a review}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {43-48}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The aim of this study was to examine the temporal relationships between FSH concentrations in blood and their effects on ovarian follicular viability, oestradiol synthesis and ovulation rates in Romney ewes. Collectively, the results showed that: (1) the number of non-atretic antral follicles (>/-1mm diameter) in sheep ovaries is influenced by plasma FSH concentrations; (2) the level of follicular oestradiol biosynthesis can be enhanced by FSH supplementation; and (3) sustained elevations of plasma FSH concentrations for 24 but not 6 h within 48 h of the onset of luteolysis significantly enhance the ovulation rate in Romney ewes.}, issn = {1176-5283}, author = {Montgomery GW} } @conference {39962, title = {Effects of shearing and herbage allowance on the intake, live weight gain and wool growth of Romney ewe hoggets in spring/summer}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {141-146}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Previous work showed that nutrition during pregnancy substantially affected ewe live weight, but that subsequent effects on ewe and lamb survival and weaning weights were small. However, farm advisers have suggested that industry ewes suffer more weight loss than in the above trials with serious consequences for ewe and lamb survival. These problems were investigated in a trial involving 2 levels of nutrition in mid-pregnancy followed by 3 levels of nutrition in late pregnancy. Average conceptus-free live weights of the 6 groups at lambing ranged from 47.6 to 38.1 kg. The ewes had weighed 53 kg at the start of the trial. Ewes severely under-nourished throughout had an 86\% survival during the trial period compared with 94\% for the 5 better-fed groups. A line of ewes within the severely under-nourished group had, however, only 80\% survival. There was a decline in the percentage of ewes lambing due to very nutrition in mid-pregnancy (78 v 85\%). Similarly, lambing percentage of those ewes lambing was affected (126 v 142\%). There was some effect on twin lamb survival. Birth weight, particularly twin lambs, was reduced by low nutrition but there was no effect on weaning weight.}, issn = {1176-5283}, author = {Hawker H and Crosbie SF and Barber M and Andrews RN} } @conference {39937, title = {Effects of varying feeding time on diurnal calving patterns in dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {35-38}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Season has important effects on reproduction in cows, although they may ovulate throughout the year. During winter, the effects of season delay puberty, prolong post-partum anoestrus and reduce fertility. There are seasonal differences in gonadotrophin secretion, pre-ovulatory follicular development and corpus luteum function. Furthermore, effects of season are more likely to be expressed when factors such as nutrition, age and lactation limit reproduction performance. Significant interactions occur between season and nutrition in the onset of puberty and the length of the post-partum anoestrous interval. In the pasture-based agricultural system in New Zealand, minimum feed supply occurs in winter when season depresses cow reproductive performance. A concentrated calving pattern is essential to improve feeding management and herd performance. To maintain a concentrated calving and high weaning percentage, calving date must be adjusted to reduce the effects of season and improve herd nutrition.}, issn = {1176-5283}, author = {Macmillan KL and Pearce MG and Copeman PJA and MacDonald KA and Kilgour R} } @conference {39964, title = {Effects of very low nutrition during pregnancy on live weight and survival of ewes and lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {151-154}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The relationship between maternal behaviour and ewe productivity was determined by least squares analyses of records for 1 year on 1050 ewes of 6 genotypes and 3 age groups. A 1 to 5 score was assigned to each ewe based on observations during tagging of lambs within 24 h of birth. Maternal behaviour was better (by 0.26 score) in 6-tooth (6th) than 4th ewes which had a score 0.27 units higher than 2th ewes. Maternal behaviour score increased by 0.18 for each unit increase in litter size (range 1 to 4). When the effect of litter size on maternal behaviour was removed, ewe genotype differences in maternal behaviour score were small. Lambs weaned/lambs born, corrected for litter size, age and genotype of ewe, increased by 0.06 for each unit increase in ewe behaviour score. The rate of increase was greater within high litter sizes. Weight of lamb weaned/ewe lambing was higher for ewes with higher scores for maternal behaviour.}, issn = {1176-5283}, author = {Smeaton DC and Wadams TK and Hockey H-UP} } @conference {39980, title = {Estimates of environmental effects and some genetic parameters for weaning weight and fleece weights of young Angora goats}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {217-220}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Forty Romney and Perendale ewes with a history of either high (W+) or low (W-) winter wool growth but similar summer wool growth were selected from a large flock. The ewes were not pregnant and were penned individually indoors and offered either 500 or 1500 g/d of high quality pelleted diet for 8 weeks in both winter and summer. The 2 breeds had similar intakes and live-weight changes, but the Romneys grew more wool. The W+ and W- ewes had very similar intakes and live-weight changes. Intakes on the low and high plane of nutrition respectively were 420 and 1093 g DM/d in winter and 422 and 1222g DM/d in summer. Corresponding live-weight changes were -71 and +54 g/d in winter and -112 and +131 g/d in summer. Summer wool growth rates were on average twice those in winter. Plane of nutrition had a much greater absolute effect on wool growth in summer than in winter (5.5 v 2.3 g/d), but the relative effects were similar (54 v 48\%). The W+ ewes grew 38\% more wool in winter than the W- ewes (5.8 V 4.0 g/d) and had a 38\% higher mean staple strength (2.7 v 1.8 g/tex). Differences between the W+ and W- ewes were similar on the high and low planes of nutrition, and also similar for the Romneys and Perendales. The variation in winter wool growth and hence in staple strength was evidently due to variation in the partitioning of nutrients to wool growth rather than to variation in feed intake.}, issn = {1176-5283}, author = {Nicoll GB} } @conference {39957, title = {Evaluation of by-product feedstuffs: acceptability to cattle and farm feeding procedures}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {121-124}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Metabolisable energy (ME) intake and body compositional and energy changes were measured in grazing lambs weaned at 4 or 12 weeks of age and in light or heavy ewes offered 3 herbage allowances during early lactation. Body energy change (MJ/kg) from 4 to 12 weeks of age varied markedly between early weaned (7.4) and suckled lambs (13.4) because of different rates of body fat deposition but was similar for both groups (16.4) from 12 to 24 weeks of age. Average efficiency of utilisation of ME for growth was 0.38 and maintenance energy requirement 0.691 MJ ME/kg W0.75/d. The ME intakes of lambs were considerably higher than those estimated using MAFF (1975) and ARC (1980) data, particularly between 4 and 12 weeks of age. The energy content of body weight loss (MJ/kg) was greater in light (60) than in heavy ewes (37) because of a higher proportion of fat in weight loss in light ewes. Absolute body energy loss (MJ/d) was lower in light (6.3) than in heavy ewes (7.9), but ME intake (MJ/d) and milk energy production (MJ/d) were similar for each class of ewe.}, issn = {1176-5283}, author = {Matthews LR and Kilgour R and Bremner KJ and Dawson J and Eden M} } @conference {39966, title = {Ewe maternal behaviour score and lamb survival}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {159-162}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Data on live weight (LW) and condition score (CS) were collected in a large scale breed evaluation at Goudies (Department of Lands and Survey, Rotorua). The LW data were obtained 4 times a year; the CS data on a 1 to 10 scale similar to the Ellinbank scale (10 fattest), were obtained on 7 occasions from April 1982 to February 1984. Seven breed groups, 5 2-breed crosses and 2 straightbreds (Angus and Herefords), were compared. The crosses were Hereford-Angus (HA, including its reciprocal), South Devon-Angus (Sd.A), Friesian-Angus (FA), Friesian- Hereford (FH) and Jersey-Angus (JA). Breed differences for LW and CS were reasonably consistent between years or seasons, in spite of large year effects and significant breed x age interactions. The CS means for JA, FA and FH were 0.9, 0.5 and 0.6 units less than for Angus cows, which in turn were 0.3 and 0.7 units lower than HA and Herefords respectively. The scores of Sd.A cows were near the average of the 7 groups together, but they were heaviest, being 22 kg above the herd mean. It is suggested on the basis of this evidence that using the same target for LW or CS for different breed crosses is unrealistic. Within breed and age groups, the correlation between August and November CS was 0.43. The equivalent figure for LW was 0.84. For each unit increase in CS, LW rose by 25.2 kg (r=0.53, range 0.42 to 0.60 on different recording occasions.}, issn = {1176-5283}, author = {O{\textquoteright}Connor CE and Jay NP and Nicol AM and Beatson PR} } @conference {39930, title = {Exploitation of the sheep{\textquoteright}s genes - the Government contribution}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {1-6}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Friesian cows of high (126) or low (104) breeding index (BI) were differentially fed during late gestation, early lactation and late lactation, and milkfat (MF) yield and condition score (CS) responses measured. In 40 cows fed to calve in either thin (CS=4) or fat (CS=5.3 in 1981; CS=6.0 in 1982) condition, a similar non-significant response to extra CS at calving was observed in both BI groups (3.0 to 8.6 kg extra MF/extra CS). For up to 4 weeks in early lactation, 24 and 32 cows in 1982 and 1983 respectively, were offered either restricted (12 to 15 kg DM/cow) or generous (50 kg DM/cow) daily allowances of pasture. Feed restriction reduced daily MF yields by 0.2 to 0.4 kg/cow, but subsequent production recovered rapidly. The extent of this recovery was less for cows of low than for cows of high BI in 1983 but not in 1982. In weeks 27 to 30 of lactation in 1983, 24 cows were offered either restricted (18 kg DM/cow) or generous (80 kg DM/cow) daily allowances of pasture. In weeks 28 to 31 of lactation in 1984, 32 cows were offered 30 kg pasture DM daily, either with or without a daily supplement of 5 kg of concentrates. Feed restriction reduced daily MF yields by a similar extent for both BI groups (0.2 to 0.3 kg MF/cow) and recovery during the final 6 weeks of lactation was similar for both groups.}, issn = {1176-5283}, author = {Callow CF} } @conference {39969, title = {Immunisation of ewes against steroids: A review}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {171-177}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The first two years{\textquoteright} (1983, 1984) results of a trial to determine the effect of immunisation with Fecundin(r) on the reproductive performance of Romney, Coopworth and Perendale ewes under hill country conditions are reported. Immunisation increased ovulation rate by 40 to 60\%, lambs born/ewe present at lambing by 19 to 26\% and lambs present at weaning by 4 to 9\%. The major reason that the increased potential lamb production of the immunised ewes was not realised in practice was the failure of the ewes that lambed to produce as many lambs as expected from their measure ovulation rate. Immunisation tended to produce a larger increase in ovulation rate in Romneys than in Coopworth and Perendales and in older ewes than in younger. Lambs of immunised ewes had lower birth weights and higher mortality rates within each birth rank than lambs from non-immunised ewes.}, issn = {1176-5283}, author = {Smith JF} } @conference {39974, title = {Implications of steroid immunisation for programmes of genetic improvement of sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {189-192}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied}, issn = {1176-5283}, author = {Clarke JN} } @conference {39949, title = {The importance of protein turnover to metabolism and carcass composition of growing lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {85-88}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A serial slaughter experiment was conducted with sheep under continuous growth and during realimentation following body weight stasis at c. 20kg for 56 days. Undernutrition resulted in negative protein and energy balance. Skeletal remodelling facilitated growth in linear dimensions while protein, water and ash decreased or remained unchanged in bone. Bone weight increases were solely attributable to large increases in bone fat. Protein appeared to be depleted in similar proportions from muscle, bone and the whole body. Realimentation resulted in a trend for compensatory growth of muscle mass relative to bone length and protein content. Within bone there was a trend for restoration of bone protein content rather than growth in bone length. Bone weight was inadequate in describing these phenomena.}, issn = {1176-5283}, author = {Schaefer AL and Davis SR and Hughson GA} } @conference {39945, title = {Improved feedback of carcass information from freezing works to farms}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {67-72}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A Sheeplan supplementary lean lamb option has been developed to assist in the selection of sheep for meat production. Output information includes a breeding value for fat-depth measurement "C" over the {\textquoteright}eye muscle{\textquoteright} and a lean growth index (LGI), combing leanness with growth performance. Performance records, including live animal ultrasonic fat depth measurements and subjective assessments of fatness by lamb drafters were analysed on 1970 ram hoggets from 25 ram breeding flocks. The average mob live weight at assessment was 47.9 kg (range 34.2 to 60.3) associated with an average fat depth C of 3.3 mm (range 1.7 to 5.6). The subjective assessment of live-animal fat depth has the advantages of speed and simplicity but further work is required to develop the most appropriate calibration techniques. The extent of within-flock variability in the animal records was examined and comparisons made between 2 methods of adjusting fat depth for live weight within each flock. The calculation of within-flock fat- weight relationships for this adjustment was adopted for use in larger flocks, but a constant exponent method is preferred when flock size is small. The wide variation in the LGI within flocks suggests considerable opportunity exists to make worthwhile genetic progress in lean growth rates.}, issn = {1176-5283}, author = {Dodd CJ and Pownall MJ} } @conference {39941, title = {Influence of follicle stimulating hormone on ovarian follicular development and ovulation rate in Romney ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {51-54}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Levels of cell mediated immunity (CJMI) were monitored in pregnant and non-pregnant control ewes to assess the impact of pregnancy on CMI in sheep. Pregnant plasma caused a significant depression in lymphocyte culture reactivity with mitogens (PHA, Con A and PWM) or with antigen (BSA) in primed animals. No defect in transformation was evident in pregnant lymphocytes per se, which gave normal transformation when cultured in control plasma. Delayed- type hypersensitivity (DTH) responses to specific antigens were significantly lower during pregnancy in response to 1}, issn = {1176-5283}, author = {Hudson N and McNatty KP and Ball K and Gibb M and Heath D and Lun S and Kieboom L and Henderson KM} } @conference {39952, title = {The influence of the Beta2-adrenergic agonist, clenbuterol, on lipid metabolism and carcass composition of sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {97-102}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Three experiments involving a total of 7 forages ranging in N content from 6.6 to 26.8 kg DM were conducted to examine comparative ad libitum digestible organic matter intake (DOMI) in goats and sheep. Digestibility trials were conducted for 7 to 10 d during each trail when water consumption and rumen NH3N concentration were also monitored. DOMI in goats was higher than in sheep with forages of less than 0.6 OM digestibility (OMD). The relationship between the DOMI (g/kgW0.75/d) of goats and sheep was described as DOMI (goats) = 0.74 DOMI (sheep) + 10.6. The ratio of DOMI (goats)/DOMI (sheep) was greater than 1.15 for forages of OMD less than 0.6 and close to 1 for forages of OMD greater than 0.6. Goats maintained higher rumen NH3N concentration (109 mg NH3N/l). Of the 5 forages with OMD<0.6, 2 resulted in rumen NH3N>50 mg NH3N/l, considered the critical level for microbial digestion. The other 3 forages resulted in rumen NH3N<50mg NH3N/l (15 to 41 mg NH3N/l) in sheep whilst goats were able to maintain higher concentrations (43 to 60 mg NH3N/l). The ability of goats to maintain higher rumen NH3N with low N diets was associated with their lower water intake. The mean water intake of goats and sheep was 1884 and 2795 ml/kg DMI, respectively. It is concluded that goats have a greater DOMI than do sheep particularly when offered forages with OMD<0.6 and of low N content partly because of their ability to maintain higher rumen NH3N concentrations.}, issn = {1176-5283}, author = {Thornton RF and Tune RK and Payne G and Larsen TW and Johnson GW and Hohenhaus MA} } @conference {39979, title = {Inheritance of loose wool bulk in Romney and Perendale sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {213-216}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Lifetime performance data were collected from flocks of 200 mixed-age Romney, Coopworth and Perendale ewes at Whatawhata Hill Country Research Station which were shorn either once yearly in November or twice yearly in May and November beginning in 1978, together with the lifetime performance data of 2-year-old replacement ewes entering these flocks in 1979 and 1980. Twice-shorn ewes were consistently heavier after shearing in November with an apparent carryover effect the following May. More of the twice- shorn ewes required dagging before shearing in November. There was a significant frequency-of-shearing x breed interaction for both total greasy and total clean wool production. Twice-shorn Romney and Perendale ewes grew more wool than once-shorn ewes. Wool growth of the Romney was greater following shearing in May compared with the other 2 breeds. Frequency of shearing did not affect ewe survival, number of lambs born, lamb survival, or weight of lamb weaned per ewe. Incidence of casting was insignificant. Average net wool returns were greater for once-shorn ewes.}, issn = {1176-5283}, author = {Bigham ML and Sumner RMW and Clarke JN and Johnson DL} } @conference {39955, title = {Intake and duodenal protein flow in early weaned lambs grazing white clover, lucerne, ryegrass and prairie grass}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {113-116}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Groups of animals were exposed to 1 of 8 by-product feedstuffs for 15 minutes daily. Each animal{\textquoteright}s consuming time was scored. Stable intakes occurred after intervals ranging from 2.3 d for whey permeate to 6.4 d for brewer{\textquoteright}s waste. Sulphuric acid whey and mother liquor were not accepted. Familiarising the animals with the pens and feeding procedures, and reducing social dominance effects resulted in increased consumption. Mixing a low preference feed in increasing proportions with a highly acceptable feed can result in cows eating previously rejected products. By this means cows were changed from concentrated deproteinised lucerne juice or corn steep liquor (highly acceptable) to mother liquor, brewer{\textquoteright}s waste or cheese whey (less acceptable) in from 5 to 15 days.}, issn = {1176-5283}, author = {Cruickshank GJ and Poppi DP and Sykes AR} } @conference {39950, title = {Leanness of lamb carcasses following restricted feeding and shearing}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {89-92}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Bray AR and Moss RA and Burton RN and Taylor AG} } @conference {39958, title = {Nutritional value of {\textquoteright}Grasslands Maku{\textquoteright} lotus grown on low fertility soils}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {125-128}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Ingestion of the spores of Pithomyces chartarum by sheep causes liver injury with a resultant rise in the blood concentration of the liver enzyme, gamma glutamyl transferase (GGT). This paper collates results concerning the effects of facial eczema (as determined by GGT levels) from 2 trials carried out in the autumn of 1981. Wash counts of spores in pasture ranged from nil to 130 000 for 45 days in February- March. Levels of GGT were determined about 1 month later. Factors significantly associated with GGT levels included premating shearing, age, nutrition level (erratic response), and ewe selection line. High levels of GGT were associated with depressed ewe performance. For each 100 iu/l increase in GGT, ewe mating and subsequent weaning weights declined by up to 0.3 and 0.4 kg respectively. Litter birth and weaning weights declined by up to 0.15 and 0.6kg/100 iu. Similarly the proportions of ewes lambing and lambing multiples were reduced by up to 2.5\%. For a modest outbreak of facial eczema causing a rise in GGT of 200 iu/l, the loss in weight of lambs weaned could be as high as 13\%.}, issn = {1176-5283}, author = {Lowther WL and Barry TN} } @conference {39973, title = {Ovulation and lambing responses with alternating steroid immunisation over 3 years}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {187-189}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Immunisation is a potentially profitable technique to improve ovine fecundity. It increases the proportion of multiple bearing ewes and lambs born as multiples. This calls for adequate feeding if production is to be sustained. The technique is therefore likely to have higher net returns in areas with ample summer feed. AS the response to the treatment is variable, the probability of not breaking even with the cost of the drug can be as high as 30\%. Where feed is adequate additional net returns of $1 to $2 per ewe can be expected if the response is a 25\% increase in lambs born per ewe joined.}, issn = {1176-5283}, author = {McMillan WH and Smith JF} } @conference {39934, title = {A physiological basis of genetic improvement in milk production of Friesian and Jersey cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {21-26}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Changes in rumen digesta and electrolyte composition were investigated in 4 high (HS) and 4 low (LS) bloat susceptible cows for 7.5 h following intraruminal loading with 10 litres water containing 0 (L), 1.76 (C), 3.52 (H) or 7.04 (HH) moles Na. Pre-treatment Na concentrations averaged 130 mmol/litre for both susceptibility groups, with increases averaging -20, 10,42 and 95 mmol/litre after addition of L, C, H and HH respectively. Susceptibility groups did not differ in rate of return of Na concentration toward pre-treatment values. Increasing Na loading decreased fluid loss from the rumen but LS cows consistently lost more fluid than HS cows, with no treatment- susceptibility interaction.}, issn = {1176-5283}, author = {Davis SR and Hughson GA and Bryant AM and MacKenzie DDS} } @conference {39944, title = {Prediction of lamb carcass composition from GR and carcass weight}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {63-66}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A lean-growth index (LGI) incorporating growth rate and the proportion of that growth which is fat is calculated by first converting live-weight differences into differences in weight of lean tissue and then adjusting these values using an estimated breeding value for fat depth. The adjustment of fat depths for weight is by within-flock double-log regression or by specifying a constant exponent in the relationship between fat depth C and live weight. Simulation studies suggested that the constant-exponent method was superior for smaller groups of sheep. Improvements in LGI by selection appear more likely to arise from genetic increases in growth rate than from decreases in weight-corrected fatness, but the inclusion of fatness in the index should lead to the production of lambs that can be taken to heavier weights before becoming overfat.}, issn = {1176-5283}, author = {Kirton AH and Duganzich DM and Feist CL and Bennett GL and Woods EG} } @conference {39961, title = {A preliminary investigation into factors affecting lamb growth on Taranaki hill country}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {137-140}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Lactating or non-lactating Coopworth ewe hoggets were offered low, medium or high herbage allowances for 8 weeks during lactation in each of 2 years. Herbage allowance had only a small effect on the penalty of a hogget lactation. Relative to their non-lactating counterparts, the hoggets that had lactated were on average 12.8 kg lighter at weaning and had a 0.29 kg lower clean fleece weight. These penalties are larger than those reported in other New Zealand studies in which the lactating hoggets were preferentially fed. The lambs reared by the hoggets had live-weight gains typical of those observed in twin lambs reared by adult ewes.}, issn = {1176-5283}, author = {Thomson NA and Brown WB and Mace MJ} } @conference {39935, title = {The presence of kallikrein-like enzymes in bovine saliva}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {27-30}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Normal calvings among 527 cows in a Ruakura Research Station herd (No.1) were not evenly distributed throughout the 24 hours. They were most frequent in the early morning (0100 h to 0600 h, 39\%) and afternoon (1300 h to 1900 h, 29\%). This diurnal pattern was consistent between years. Altering feeding time from 0700 h to either 1600 h or 1900 h did not increase the frequency of daylight calvings. Feeding at 1900 h did produce 2 periods of intensive grazing each 24 h instead of only one. If a beneficial change in calving pattern is to be produced, it may be necessary to disrupt the period when most cows rest (0100 h to 0600 h) by feeding at around 0300 h.}, issn = {1176-5283}, author = {McIntosh JT and McLaren RD and Carr DH and Howe GW and Cockrem FRM} } @conference {39938, title = {Replacement policies for dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {39-42}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {In anoestrous ewes that have been primed with progestagens, the introduction of oestrous ewes together with the teaser rams at progestagen withdrawal increased the percentage of ewes exhibiting oestrus over the subsequent 7 days (19.\% teaser rams only v 24.4\% teaser rams + oestrous ewes; Experiment 1) and the percentage of ewes ovulating in the subsequent 5 days (7.7\% teaser rams only v 21.6\% teaser rams + oestrous ewes; Experiment 2). The introduction of oestrous ewes without teaser rams in Experiment 2 failed to stimulate anoestrous ewes to ovulate. When rams were placed with oestrous ewes for 2 days before they alone were introduced to anoestrous ewes, the percentage of ewes ovulating was similar to when rams plus oestrous ewes were present together (38.1\% stimulated teaser rams v 35.0\% teaser rams + oestrous ewes; Experiment 3). Both of these treatments resulted in more ewes ovulating than in the isolated ewes (0.0\%) with the response to unstimulated teaser rams (19.5\%) and to oestrous ewes alone (9.5\% being intermediate.}, issn = {1176-5283}, author = {McArthur ATG} } @conference {39978, title = {Resistance and susceptibility to fleece yellowing and relationships with scoured colour}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {209-212}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Data from 1048 young Angora goats by 15 sires in the Department of Lands and Survey{\textquoteright}s flock at Waitangi were used to obtain preliminary estimates of the effects of year, age of dam, sex, rearing rank and birth day (age). Characters studied included weaning weight, 6- and 12- month fleece weight, and yearling fleece weight (the sum of 6- and 12- month weights). Estimates were also obtained of the heritabilities of, and the genetic and phenotypic correlations among, these traits. The weaning weights of kids out of dams aged 3, 4, 5 and 6+ years of age were heavier (P<0.001) than those out of 2-year-old dams by 1.9, 2.2, 2.0 and 2.5 kg respectively. Corresponding differences for 6-month fleece weight of kids were 0.05, 0.05, 0.04 and 0.04 kg (P<0.01) but those for 12-month fleece weight were not significant. Males were heavier at weaning than females (1.6 kg, P<0.001) and also had heavier 6-, 12-month and yearling fleece weights (0.08, 0.10 and 0.18 kg respectively; P<0.001). Single-reared animals had significantly heavier weaning weights and 6-month and yearling fleece weights than multiple- reared animals (2.4, 0.09 and 0.11 kg, respectively). Age was a highly significant source of variation for all traits. The heritabilities of weaning weight, and 6-, 12-month and yearling fleece weights were respectively 0.28, 0.23, 0.40 and 0.53. Genetic correlations between weaning weight and 6-, 12-month and yearling fleece weights were respectively 0.0, 0.38 and 0.24. Corresponding phenotypic correlations were 0.58, 0.28 and 0.44.}, issn = {1176-5283}, author = {Wilkinson BR and Aitken FJ} } @conference {39936, title = {Response of cows differing in bloat susceptibility to intraruminal water and electrolyte loading}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {31-34}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A simulation model of dairy herds was built to examine the economic consequences of alternative culling policies. Only culling cows on the basis of their first lactation was examined because previous studies had show that it is not worthwhile acquiring more information before making the culling decision. The simulation model shows that the culling decision is sensitive to the ratio of cull salvage value to replacement cost. At a ratio of 0.7, a third of first lactation cows should be culled. Used optimally to make replacement decisions, herd testing is worthwhile particularly if the less expensive alternate month test is used.}, issn = {1176-5283}, author = {Carruthers VR} } @conference {39977, title = {A review of the importance of wool traits as genetic improvement objectives and selection criteria for New Zealand Romney sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {203-208}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Genetic parameters of loose wool bulk were estimated by half- sib correlations for Romney ewe and ram hogget fleeces sampled at Tokanui Research Station, Romney and Perendale ewe hogget fleeces sampled at Rotomahana Research Station and Perendale ewe hogget fleeces sampled from 5 industry flocks. Daughter-dam analyses were used to estimate similar parameters for Perendale ewe fleeces sampled at Whatawhata Hill Country Research Station. Heritability estimates for loose wool bulk were 0.34}, issn = {1176-5283}, author = {Wickham GA and McPherson AW} } @conference {39951, title = {Skeletal changes and some muscle-skeletal relationships during growth and undernutrition in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {93-96}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Eight Friesian bull calves from high breeding index (HBI) parents (mean BI=134) and 8 from low breeding index (LBI) parents (mean BI=104) were allocated to 1 of 2 levels of milk intake from 3 weeks of age until weaning at 7.5 weeks of age. The calves were then grazed at pasture and weighed at 21 to 25 weeks of age. LM calves consumed more herbage organic matter (OM) both before (P<0.01) and for 3 weeks after (P<0.05) weaning. Increasing daily milk intake by 1 litre decreased daily herbage OM intake by 0.11 kg. The total DE intake from 3 weeks to 10.5 weeks of age did not differ significantly between treatments. HM calves grew faster (P<0.05) than LM calves in the pre-weaning period, but no differences were observed from them on. At no stage were significant differences observed in calf live weights between milk treatment groups. There were significant differences in growth rate or herbage intake between BI groups, nor any significant interactions between BI and levels of milk intake.}, issn = {1176-5283}, author = {Young MJ and Sykes AR} } @conference {39943, title = {Suppression of T-cell function in the pregnant ewe}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {59-62}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Increased payment to farmers for leaner lamb carcasses places greater emphasis on specifying target carcass weights and grades on individual farms. In the past there has been little objective information available to help the farmer set these targets and make livestock buying and selling decisions. At the Tomoana freezing works in Hawkes Bay new computer outputs have been introduced to provide the farmer with better information for farm management decision-making. A more detailed lamb grading analysis presenting the number of carcasses within each grade at each carcass weight, and a new output named a "fat trend report" are provided. The fat trend report estimates the relationship between the GR fat depth and carcass weight for each mob of lambs slaughtered. Combined with an iso-dollar overlay, the fat trend report assists in establishing production targets in future mobs for each sheep breed and sex farmed. It is suggested that financial incentives for leaner lamb carcasses should be further increased, to bring carcasses closer to the New Zealand Meat Producers Board{\textquoteright}s ideal.}, issn = {1176-5283}, author = {Griffin JFT and Davis GH} } @conference {39942, title = {Swimming speed and fertilisation rates of ram sperm from high and low prolificacy populations}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {55-58}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The composition of 2 groups, comprising 70 and 837 lamb carcasses, was predicted from hot carcass weight (HCW) and GR separately and together, these being the main observations considered in the export lamb carcass grading system. GR was a better predictor of composition than HCW with the 2 in combination tending in most cases to be slightly better than GR alone. These measurements could account for 50 to over 70\% of the variation in carcass fat and bone and 26 to 47\% of the variation in carcass muscle. On average, for each 1 mm decrease in GR, carcass fatness decreased by about 1 percentage unit, muscle increased by about 0.5 percentage units and carcass bone increased by just under 0.5 percentage units.}, issn = {1176-5283}, author = {Moore RW and Wilson MC and Duganzich DM} } @conference {39904, title = {The association between selenium status and milk production in dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {153-154}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Ewe hoggets were run at 2 stocking rates and at 4 levels of injection with hydroxycobalamin (0, 30, 100 and 3,000 }, issn = {1176-5283}, author = {Ryan TJ and Sproule RA and Fraser AJ and Anderson DC and Clark RG and Pederson EO} } @conference {39917, title = {The breath-test for sheep: a possible means of identifying lean genotypes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {205-208}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The effect of Ralgro on growth and carcass composition was examined in 3 lamb trials, in young and 15-month old bulls and in spayed and entire heifers. There was no consistent growth response to Ralgro in any of the trials, except for the spayed heifers. Increased meat percentage from Ralgro was found only in young bulls. Aggressive bull behaviour was controlled by Ralgro only in young bulls from April-July at approximately 8 to 11 months of age.}, issn = {1176-5283}, author = {Peterson SW} } @conference {39918, title = {Consumer acceptance of ram and wether meat in the U.S.A.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {209-210}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Industry Coopworths, industry Perendales and closed lines of Romneys intensely selected for (HFR) or against (LFR) twinning, were raised in individual farmlets with ewe stocking rates of 26 (H), 21 (M) and 16 (L) ewes/ha. Lambs were slaughtered at 16, 20 and 24 weeks of age. The correlated response to selection for twinning was decreased fat depth at equal ewe stocking rates and birth-rearing status. HFR compared to LFR also increased fat depth less when weight was increased by a reduction in stocking rate. Perendales compared to Coopworths had less fat depth and increased fat depth less, when weight was increased by a reduction in stocking rate. The results suggest that fatter breeds will be comparatively leaner at high stocking rates.}, issn = {1176-5283}, author = {Field RA} } @conference {39900, title = {The determination of mineral requirements of sheep and cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {139-142}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Factors to be considered in implementing a programme for the prevention and treatment of trace element deficiencies in livestock are outlined. These are species, age, dietary requirements, seasonal patterns in the deficiency, the pharmacology of the therapeutic agent, its mode of administration and cost. Specific treatment of cobalt, selenium and copper deficiency is discussed.}, issn = {1176-5283}, author = {Grace ND} } @conference {39913, title = {The development and application of ELISA detection of Lolium endophyte in ryegrass staggers research}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {185-188}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {To apportion the intake of metabolisable energy (MEI) used for synthesis of lean and fat tissue, current knowledge of substrate oxidation and substrate utilisation for biosynthetic reactions has been combined with estimates of fat and protein turnover to develop models of energy metabolism and nutrient fluxes in a lean 20 kg male and a fat 40 kg female sheep, each gaining 200 g/d. When the most efficient pathways and lowest turnover rates are employed the biosynthetic reactions account for 38 and 34\% of MEI in the lean and fat animals. These values rise to 45 and 43\% of MEI respectively when higher estimates of turnover and less efficient pathways are used in the calculations. Hormonal regulations of metabolite utilisation is believed responsible for such differences but hitherto, only glucose-insulin system has been quantitated. Two techniques used for its quantitation are described to provide examples of the methods needed to elucidate the control of nutrient utilisation and ultimately body composition in ruminants.}, issn = {1176-5283}, author = {Musgrave DR and Fletcher LR} } @conference {39901, title = {Diagnosis of mineral deficiencies in sheep and cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {143-146}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Results from vitamin B12 response trials are used to illustrate a methodology which it is claimed will provide a more useful interpretation of animal tissue analyses for the diagnosis of trace element deficiencies. Traditional reference ranges which divide tissue levels into the categories of responsive, marginal, and adequate are replaced by reference curves which, for a given tissue level, provide the expected response and the probability of an {\textquoteright}economic response. The approach should provide farmers and veterinarians with better information to decide on remedial action. The prospects look promising for the production of reference curves for cobalt and selenium, and hopeful for copper. It is suggested that the methodology could be applied in other biological systems involving deficiencies, in particular, to the diagnosis of phosphorus and other deficiencies in plants.}, issn = {1176-5283}, author = {Clark RG and Towers NR} } @conference {39894, title = {Diet selection of young ruminants in late spring}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {109-112}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Earlier trials indicated that pasture quality (\% green DM in the sward) and pasture accessibility (green DM/ha) can be more limiting to ewe live-weight gain prior to mating than pasture allowance. Two trials investigated the effects of summer grazing management on subsequent pasture quality. From weaning to the start of flushing ewes were grazed lax (residual >2000 kg DM/ha) or hard (residual <1500 kg DM/ha). A live-weight difference of 4 kg occurred at the start of flushing and reduced to 2.5 kg at mating. Main effect results showed that at similar green allowances, ewes flushed on pasture which had previously been hard grazed had live-weight gains 20 to 30 g/d more than ewes on lax grazed pasture. There were no differences in ovulation rate but he live-weight results suggest that there would on average be an advantage to flushing on hard grazed pasture. Wool production was affected similarly to live weight. Management implications are discussed.}, issn = {1176-5283}, author = {Hughes TP and Sykes AR and Poppi DP} } @conference {39924, title = {Dressing percentages of lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {231-234}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Overseas comparisons have indicated sheep breeds and strains with improved growth rates and lean meat production to those currently available in New Zealand. Most studies in U.K. and Eire have generally shown fastest growth and lean tissue gain amongst offspring by the large down breeds, the Suffolk and Oxford. These results are generally comparable with New Zealand studies. In addition, there has been considerable European interest shown in the Texel for its high yield of lean relative to fat and bone, including lean yield in high value areas of the carcass. The white fleece and moderate fecundity of this breed also favour its maternal use to improve flexibility of lean lamb production. In most studies in the U.S. crossbred lambs sired by Suffolk rams fastest to reach slaughter weights before other meat breeds. This breed is of widespread popularity for lamb production in the U.S. Indirect comparisons suggest a greater growth superiority (5\%) of crossbred lambs sired by U.S. Suffolks overseas compared with those sired by New Zealand Suffolks in this country.}, issn = {1176-5283}, author = {Kirton AH and Carter AH and Clarke JN and Duganzich DM} } @conference {39910, title = {Effect of herbage allowance on the performance of pregnant beef heifers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {173-176}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Investigations into perennial ryegrass staggers, a neurotoxic disease affecting sheep, cattle, horses and deer in New Zealand, recently incriminated a fungus growing as a endophyte in perennial ryegrass in the occurrence of this disease. This Lolium endophyte (an Acremonium sp.) is most prevalent in the lower parts of infected ryegrass plants (leaf sheath) but invades the inflorescence and seed. Newly-emerging ryegrass seedlings are so infected. The close association of the endophyte with the present of lolitrems, potent neurotoxic tremorgens previously isolated from staggers-producing pasture samples, further incriminated the endophyte in the occurrence of ryegrass staggers. Subsequent lamb grazing trials on plots sown with lines of either high- or low-endophyte ryegrass seed confirmed that adequate intakes of short- grazed ryegrass material readily produced ryegrass staggers in all lambs grazing the endophyte-infected plots but there was little or no disease on low-endophyte plots identically grazed. The trials also revealed that the spring-sown high-endophyte ryegrass plots had considerable drought resistance and persistence when compared with low-endophyte plots. The infected swards were found to be highly resistant to Argentine stem weevil attack and a significant insect- feeding deterrent factor has since been detected in endophyte-infected ryegrass. A subsequent sheep grazing trial was indicated that plots sown in autumn with fungicide-treated seed to control endophyte and then conservatively grazed in the first year subsequently gave good production and also provided excellent protection from ryegrass staggers.}, issn = {1176-5283}, author = {Nicoll GB and Smeaton DC and McGuire KR} } @conference {39873, title = {The effect of melatonin on the onset of first oestrus in Romney ewe lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {21-24}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {There is increasing evidence that a non-steroidal compound, inhibin, produced by the ovary is involved in the regulation of follicle stimulating hormone (FSH) production by the pituitary. Our studies have shown that ovarian inhibin is present in follicular fluid, that it is synthesised exclusively by follicular granulosa cells, that androgens regulate its synthesis and that it is predominantly a product of healthy follicles, i.e. follicles with the potential to attain ovulatory granulosa cell inhibin production which then suppresses pituitary FSH secretion thereby limiting the number of follicles that can be stimulated to develop to ovulatory maturity. Ovulation rates of Romney ewes actively immunised with a semi-purified preparation of inhibin derived from bovine follicular fluid were significantly higher than those of control ewes (2.06 }, issn = {1176-5283}, author = {Moore RW and Miller CM and Lynch PR and Welch RAS and Barnes DR and Hockey H-UP} } @conference {39919, title = {Effect of {\textquoteright}Ralgro{\textquoteright} on growth, body composition and behaviour of lambs, heifers and bulls}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {211-214}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {In 5 trials involving lambs grazing either lotus (L) or white clover (WC) in summer/autumn, those on L were consistently less fat. In trial 1 Romney wether lambs (n=12), grazed 62 days, had weight-corrected carcass fat depths C of 2.1 (L) and 3.4 (WC) mm. In trial 2 Romney hoggets (n+10) grazed 40 days, L had a lower side fat percent than WC at a similar weight. Trial 3 compared Romney lambs (n=20) of the same weight. After 80 days fat depths were significantly lower for L. In Trial 4 Southdown x Romney lambs (n=24), grazed for 45 days. Several measures of fatness were significantly lower in the L group after correcting for initial fatness and carcass weight. Trial 5 was similar to trial 4 (n=16), but continued over 76 days and the differences in fatness were greater. Growth rates of the lambs in these trials were in favour of the WC group by an average of about 15 percent. The lotus tannin content was 10 to 30 g/kg DM. It is concluded that lambs grazed on pure lotus are likely to be less fat than lambs of the same weight grazed on clover, possibly because the protein of lotus is to some extent protected from rumen degradation by tannins, thus effectively increasing its protein content.}, issn = {1176-5283}, author = {Bass JJ and Jagusch KT and Jones KR and Reardon TF and Day AM} } @conference {39872, title = {Effect of season on ovarian and pituitary activity in cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {19-20}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {One hundred and four ewe lambs born in 1980 to either ewes that had been immunised against steroid hormones or untreated control ewes were retained for study of their subsequent growth and reproductive performance. There was no significant effect of dam immunisation on growth rate or reproductive performance as hoggets, 2-tooths or 4- tooths. Dam breed (Coopworth or Romney) was the major factor influencing reproductive performance. Mean lamb birth weight was 3.7 kg, weaning weight 18.7 kg, hogget mating weight 40.0 kg, 2-tooth mating weight 54.4 kg and 4-tooth mating weight 60.4 kg. At 9 months of age 83\% had exhibited oestrus and their ovulation rate was 1.08, as 2- tooths, 96\% mated in the first cycle with an ovulation rate of 1.68 and a conception rate of 80\% to first service. They had a lamb drop of 1.49 lambs born/ewe joined and weaned 1.35 lambs/ewe joined. The respective figures as 4-tooths were 98\%, 1.8, 85\%, 1.43 and 1.34. These data indicate that immunisation of ewes against steroid hormones has no adverse effects on the performance of their progeny.}, issn = {1176-5283}, author = {McNatty KP and Heath D and Lun S and Henderson KM and Hudson N and Gibb M and McDiarmid J and Montgomery GW and Thurley DC} } @conference {39879, title = {Effect of shearing on meat and wool production from lambs reared on hill country}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {45-48}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The effect of winter and early spring feeding levels, lambing status and ewe age on staple strength, fibre diameter at the point of break, and position of staple break were measured in pregnant Romney and Coopworth mixed-age ewes at Whatawhata and Ruakura, respectively. Mid-pregnancy feeding levels produced significant differences in staple strength (37 v 20 newtons/kilotex in the Romney; and 52 v 45 N/ktex in the Coopworth) and diameter at the point of break (37 v 34 }, issn = {1176-5283}, author = {Sumner RMW} } @conference {39906, title = {The effect of stocking rate on response to cobalt supplementation in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {159-162}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Six young red deer stags were placed on a photoperiod of 5 alternating periods of 2 months of 16 hours light: 8 hours dark each day (16 L:8 D) followed by 2 months of 8 L:16 D for 20 months. Food intake, whether the antlers were present, and if present, whether growing, cleaning or hard and testis diameter were recorded. Each stag showed 5 peaks and 5 troughs of food intake in response to the manipulated photoperiod. There were 4 cycles of gonadal development and regression as the testes did not descend from the inguinal canal during Period 1; testes grew in short day periods and diminished in size in long day periods. There were 4 cycles of antler growth and casting; antler cleaning occurred on short days and casting on long days. Male red deer are capable of responding to a square wave daylength pattern as a sinusoidal pattern.}, issn = {1176-5283}, author = {McQueen IPM} } @conference {39923, title = {The effects of lamb breed, slaughter age and sex on carcass fat depth and export grade}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {227-230}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A least squares analysis of the weight of 15 individual export cuts from 808 carcasses of 20-month old steers identified significant effects of carcass weight, carcass fat measurements, carcass grade and sire breed on the weight of export cuts. Increasing carcass weight had a positive effect on cut weight but increasing carcass fatness had a variable effect on weight of cut. The weight of cut marketed with negligible subcutaneous fat (cube roll) decreased in weight by 7\% as carcass fat depth increase from 4 to 12 mm. In contrast a cut which included subcutaneous fat increased in weight by 15\% over the same fatness range. The data show that the most equitable pricing system (schedule) would take account of weight of individual cuts.}, issn = {1176-5283}, author = {Geenty KG and Young SR and Clarke JN and Wilson JA} } @conference {39890, title = {Embryonic and genetic engineer - Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {87-90}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The evidence on the influence of herbage allowance and sward characteristics upon animal performance and herbage production is reviewed briefly, with particular reference to the prediction of animal performance, the use of decision rules in grazing systems and understanding of animal/sward interrelationships. Attention is concentrated on evidence from temperature grasslands, with particular reference to New Zealand results. Simple management rules based on herbage allowance or residual dry matter indices have made a major contribution to improvement in the efficiency of grazing management. However, their use as general indices is restricted by the interdependence of the effects of variation in allowance and sward conditions upon animal performance. Furthermore allowance-based studies make only a limited contribution to understanding of the factors influencing the links between the plant and animal components of grazing systems. It is suggested that more attention should now be concentrated on the causative effects of variation in sward characteristics upon both herbage production and animal performance}, issn = {1176-5283}, author = {Baker RL} } @conference {39927, title = {Expected selection responses in lamb carcass composition and weight}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {243-248}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Twenty eight Border Leicester 2-tooth rams (mean live weight 70 kg) were scored for fatness on a 10-point scale by 6 drafters and back fat thickness was measured by ultrasonic probe (UFD). Chemical fat percentage (mean 33.9\%) was determined on a half-carcass of each ram. Mean carcass weight, measurement C and GR were 38.0 kg, 12 mm and 28 mm respectively. Mean drafters{\textquoteright} fat score was more highly correlated with \% carcass fat (+0.83) than UFD (+0.67). The prediction of fat-free carcass weight (FFCW) from live weight plus UFD (R2=0.72, RDS 1.24 kg) or drafters{\textquoteright} fat score (R2=0.76, RSD 1.14 kg) was superior to prediction from live weight alone (R@=0.59, RSD 1.49 kg). The inclusion of UFD o9r drafters{\textquoteright} fat score increased the efficiency with which rams were ranked for fat-free carcass weight. Selection of the top 10\% of rams ranked on the prediction of FFCW from live weight achieved 75\% of the potential selection differential. Inclusion of either UFD or drafters{\textquoteright} score improved the potential to 95\%.}, issn = {1176-5283}, author = {Bennett GL and Clarke JN} } @conference {39921, title = {Fatness of lambs grazed on {\textquoteright}Grasslands Maku{\textquoteright} lotus and {\textquoteright}Grasslands Huia{\textquoteright} white clover}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {219-222}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Crossbred lambs involving specialist meat breed (Expt. A) or long-woolled breeds (Expt. B) were slaughtered at ages ranging from 12 to 30 weeks. Carcasses were classified retrospectively into current export grades according to their weight and fat measurement GR. In both experiments measurement GR was related to carcass weight (r=0.57 to 0.83) and increased, on average, by just over 1 mm per kg carcass weight increase. Proportions of carcasses grading {\textquoteright}trimmer{\textquoteright} or {\textquoteright}overfat{\textquoteright} increased at carcass weights above 15 kg or at slaughter ages greater than 18 weeks. In Expt. A, 4\% of carcasses graded {\textquoteright}overfat{\textquoteright} at the 12 week slaughter age and 81\% at 30 weeks. There was little difference in the grade distribution of carcasses among sire breeds in Expt. A (Southdown, Suffolk and Dorset Down) but in Expt. B lambs reared by Corriedale ewes showed higher proportions of {\textquoteright}trimmer{\textquoteright} (25\%) and {\textquoteright}overfat{\textquoteright} (18\%) carcasses compared with those reared by Romneys (10\% and 2\% respectively). It is suggested that the higher carcass fat of lambs from Corriedale ewes is due partly to greater milk consumption compared with those suckled by Romneys.}, issn = {1176-5283}, author = {Purchas RW and Keogh RG} } @conference {39881, title = {Fleece tenderness: the effect of nutrition, age and lambing status on pregnant Romney and Coopworth mixed-age ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {53-56}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The potentially high levels of productivity of fitch - 2 litters per year, 8 young per litter - is rarely achieved in practice. Annual litter rates vary from 0.9 to 1.7 per female kept, due to high rates of false pregnancy (up to 90\%). Kit mortality can reach high levels (to 50\%). Young fitch grow rapidly and reach mature body size at 20 weeks (males 1400 g; females 800g). Subsequent fluctuations in body weight are attributable to adipose depositions.}, issn = {1176-5283}, author = {Fitzgerald JM and Smeaton DC and Jagusch KT} } @conference {39914, title = {Grazing behaviour of sheep and ryegrass staggers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {189-192}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Two experiments investigated relationships between biochemical measurements and carcass fat in lambs. In the first, artificially reared Dorset lambs, weaned at 5 (early) or 13 (late) weeks were slaughtered at 5, 9 and 13 weeks for carcass fat determination. In the second experiment, 330 Coopworth male lambs (entire and castrate), were weaned at 9 weeks of age and slaughtered at 21 weeks. At 9 and 13 weeks of age early weaned lambs which had lower carcass weights had significantly lower glucose and insulin levels, and less internal and carcass fat than milk fed lambs. In the second experiment a similar carcass weights entire lambs were leaner than castrates and had lower blood glucose. In contrast to results in the first experiment, lambs grown to slaughter under a uniform dietary regime in the second showed a negative correlation between insulin and fat measurements. It is suggested that insulin is an important regulator of fat deposition in the milk fed lamb but its exact role in the ruminant lamb remains unclear.}, issn = {1176-5283}, author = {Keogh RG} } @conference {39885, title = {Herbage allowance, pasture quality and milkfat production as affected by stocking rate and conservation policy}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {67-70}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Four cows were fitted with unilateral temporary cannulae to both parotid and mandibular glands in an experiment designed to determine which salivary proteins were secreted by these glands. Parasympathomimetic stimulation produced a large salivary flow from the parotid gland (50.8 ml/min) with a relatively low protein concentration. Mandibular flow rates were lower, but the protein concentration was high giving a total protein of 1.3 mg/min. Sympathomimetic stimulation, during a parasympathomimetic booster, reduced the flow rates from both glands but increased the total protein output 7-fold from the parotid and 8-fold from the mandibular gland. Band 4 was the major protein secreted by the parotid gland while bands 3, 7 and 8 were the major bands secreted by the mandibular gland.}, issn = {1176-5283}, author = {Thomson NA and Lagan JF and McCallum DA} } @conference {39895, title = {Influence of age of early weaned lambs on intake, digestibility and retention time of clover hay}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {113-116}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A simulation model was used to generate functions to evaluate winter and spring feed priorities for replacement hoggets and ewes on North Island hill country. The functions relate ewe, hogget and lamb live weights at the end of the respective seasons to seasonal stocking rate and live weight and pasture cover at the start of the season. The site simulated was Ballantrae Hill Country Research Station. At high stocking rates, switching priorities from hoggets in winter (relative stocking rate, 1 hogget/ewe) to ewes in spring (2.4 hoggets/ewe) provided no benefit to ewe and hogget live weight at weaning, compared to other selected winter/spring strategies (eg. 1.2/2.05 or 1.4/1.8 hoggets/ewe). However, lamb weaning weight was greater under the former strategy. The same pattern held for lower stocking rates. Imposition of system constraints reduced the apparent advantages displayed in the general functions. Rationing feed to hoggets in spring was important to success at high hogget stocking rates.}, issn = {1176-5283}, author = {Cruickshank GJ and Poppi DP and Sykes AR} } @conference {39893, title = {Influence of green leaf distribution on diet selection by sheep and the implications for animal performance}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {105-108}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Twelve lambs, weaned at 6 weeks of age, were used to study the development of rumen function from 6 to 24 weeks of age when offered clover hay ad libitum. Six of the lambs were cannulated at the abomasum on weaning and the remaining 6 remained intact. Dry matter intake (g/kg live weight) increased rapidly until 10 weeks of age and subsequently remained constant at 33 to 37 g DM/kgLW. in vivo DM digestibility and marker rumen retention time decreased initially (0.693 in week 7 v 0.664 in week 9 and 14.5 hours in week 8 v 10.9 hours in week 12 respectively) but were constant thereafter. The proportion of digestible DM apparently digested in the rumen was low (0.45) but was similar at 8, 12 and 16 weeks of age. There were no differences between the intact and cannulated lambs in DM intake and digestibility or in marker retention time in the rumen.}, issn = {1176-5283}, author = {L{\textquoteright}Huillier PJ and Poppi DP and Fraser TJ} } @conference {39925, title = {Influence of individual beef cuts on net carcass value}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {235-238}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Expected rates of genetic change in lamb growth and composition were calculated for 2 different selection goals; increase in lean growth rate (LRG) and decrease in weight-adjusted \% fat (APF). Carcass fatness was measured in a number of ways on an animal{\textquoteright}s own or its relatives{\textquoteright} performance. Under either selection goal, all selection programmes resulted in reduced \% fat adjusted for age. All selection programmes for either selection goal improved lean weight but there was little improvement over selection for live weight alone. Alternatively, use of fat measurements did not decrease lean weight improvement and resulted in leaner carcasses. Changing carcasses from 13.5 kg and 25\% fat to at least 15 kg and no more than 24\% fat was most quickly achieved by selecting against APF.}, issn = {1176-5283}, author = {Selbie PB and Nicol AM and Mellon MJ and Bass JJ and Duganzich D} } @conference {39880, title = {The influence of pasture allowance on performance of autumn- shorn lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {49-52}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Seasonal wool growth and staple strength were measured in mature, non-pregnant Romney ewes individually penned indoors or confined as a group in a yard outdoors and offered a maintenance ration of lucerne chaff. Clean wool growth was lowest during winter (4.6 and 5.0 g/d for indoor and outdoor ewes, respectively) and greatest during summer for indoor (11.3 g/d) or spring for outdoor (11.9 g/d) ewes. Efficiency of wool growth (g wool growth/d per kg dry matter intake/d) for indoor sheep was 5.6, 8.8, 11.8 and 7.8 during winter, spring, summer and autumn, respectively. There were positive relationships between mean wool growth, staple strength and efficiency.}, issn = {1176-5283}, author = {Pownall DB and Lucas RJ and Abrahamson M} } @conference {39870, title = {The insemination of sheep with fresh or frozen semen}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {11-14}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The preovulatory follicle in oestrous cycling Angus cow was larger (P<0.01) and contained more granulosa cells (P<0.01) in May and June than in October. Also in May and June, the corpora lutea were heavier (P<0.05) and secreted more progesterone (P<0.01) than in October. In contrast, the luteinizing hormone peak frequency and plasma prolactin concentrations were higher (P<0.01) in October than in May and June. Seasonal differences in ovarian activity are probably a direct consequence of seasonal differences in pituitary gonadotrophin secretion.}, issn = {1176-5283}, author = {Tervit HR and Goold PG and James RW and Fraser MD} } @conference {39909, title = {Integrating management of sheep and deer - Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {171-172}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A trial at Tokanui and Templeton Research Stations was designed to compare the Charolais and Murray Grey breeds as terminal sires. There were calvings at both stations in 1980, and at Tokanui in 1981. Ten Murray Grey and 7 Charolaise sires were used over crossbred cows to calve at 3 years or older in 1980, with the same cows in 1981, generating respectively 231 and 223 calves/breed. Sires were used in common across years and stations by artificial insemination, and reference sires were used to link earlier Charolais data. Of calves born, 1.7\% sired by Murray Greys and 7.2\% sired by Charolaise bulls had birth difficulties; in total 3.5\% and 7.6\% of calves respectively died before weaning. Relative to Murray Grey-sired calves, birth weights of Charolaise-sired calves were 8 kg (24\%) higher; weaning weights at 4 to 5 months of age were 22 kg (13\%) higher, with a similar percentage margin at 12 and 16 months. Weight of calf weaned per cow calving was 6\% higher for Charolais-sired calves, making due allowance for different calf death losses and gestation lengths.}, issn = {1176-5283}, author = {Harbord MW} } @conference {39922, title = {Lamb live weights at slaughter and carcass grades}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {223-226}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Dressing percentage (DO\%), the dressed carcass expressed as a portion of live weight, is markedly influenced by the particular definition used. Farmers usually want to estimate cold (works) carcass weights (CCW) from live weights taken on lambs recently removed from pasture (FLW). Gut fill plays a major role in DO\%. As lambs empty out after removal from pasture, DO\% increases until this effect is offset by loss of carcass and organ weights from increasing periods of starvation. Data on 2207 weaned and shorn lambs ranging from 10 to 46 kg FLW and slaughtered over 3 seasons could be described by the regression: CCW (kg) = 0.473 FLW (kg) - 1.92, RSD = 0.67 kg, r=0.95. DO\% calculated from this regression for lambs slaughtered close to the New Zealand mean CCW of 13 kg averaged 41\% and increased as FLW increased. Shorn lambs of similar weight sired by longwool breeds had lower DO\% than lambs sired by Down breeds. Lamb DO\% dropped following weaning. Lambs with carcasses in the leaner A and Y grades dressed lower than lambs in the fatter pre 1983-84 P grade when compared at the same live weight, illustrating that DO\% increases as lambs get fatter.}, issn = {1176-5283}, author = {Bray AR} } @conference {39907, title = {Live-weight gains of lambs on limed and unlimed pasture at similar levels of nutrition}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {163-166}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied}, issn = {1176-5283}, author = {O{\textquoteright}Connor MB and Jagusch KT and MacLean KS and Edmeades DC} } @conference {39877, title = {Management and breeding policies for the use of the Booroola F gene for increased flock prolificacy}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {37-40}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Three hundred Romney, Coopworth and Perendale wether lambs reared at the Whatawhata Hill Country Research Station were shorn in either December and April, February and April or only in April before slaughter in May and either well or poorly fed between December and May. Shearing did not affect carcass weight. GR fat depth or export fatness grade. Lambs shorn in December grew most clean wool. Well-fed lambs had a heavier, fatter carcass with more graded P. There was no interaction between shearing treatment and level of feeding. The trial was repeated on 11 commercial hill country farms in the northern half of the North Island using 150 lambs/farm. On 1 farm, where average growth rate exceeded 200 g/d, there was a positive effect on carcass weight from shearing lambs twice before slaughter. On all other farms (growth rates less than 150 g/d) there was no effect (9 farms) or a negative effect (1 farm) on carcass weight from shearing lambs at weaning. Export fatness grade was unaffected by shearing treatment. Wool production was unaffected by shearing treatment for 6 farms, greatest for 2 farms when shorn in December and April and greatest for 1 farm when shorn in February and April. Total net returns from meat and wool for the farm with the fastest growth rate were unaffected by shearing treatment. Total net returns for all other farms were greatest for the group shorn once prior to slaughter. Seventy four wether lambs and 105 ewe lambs were shorn either 3 weeks, 24 hours, or left unshorn before slaughter. Shearing treatment did not affect carcass weight, GR fat depth, export fatness grade or muscle pH.}, issn = {1176-5283}, author = {Metherell JA} } @conference {39929, title = {Methods of ranking two-tooth rams for fat-free carcass growth rate}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {253-256}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Eight herds each of 24 Friesian cows were stocked at 3.7 cows/ha on separate farmlets during 1982-83 and 1983-84. Annual production per5 hectare averaged 710 kg fat, 537 kg protein, 740 kg lactose and 16.7 t solids corrected milk (SCM). Annual DM intake was 15.8 t/ha and live weight (LW) during lactation, 1487 kg/ha. In a contemporary farmlet trial at an adjoining dairy, 4 purebred Jersey herds each of 15 cows were stocked at 2.8, 3.3, 3.8 and 4.3 cows/ha. Regression analysis was used to derive estimates of the performance of the Jerseys at the same stocking rate, and at a stocking rate that resulted in the same LW/ha, as the Friesians. At a common stocking rate of 3.7 cows/ha, the Friesians were estimated to produce 7, 15, and 13\% more fat, protein, and SCM/ha than the Jerseys. Annual conversion efficiency (g milk constituent/kg DM) of the Friesians was estimated to be 10\% higher for fat and 18\% higher for milk solids than the Jerseys. At the same LW/ha, requiring a Jersey stocking rate of 4.21 cows/ha, the Friesians were estimated to outproduce the Jerseys by 3, 13 and 10\% for fat, protein and SCM/ha respectively. Annual conversion efficiency for the Friesians was estimated to be 15 and 25\% higher for fat and milk solids respectively than for the Jerseys. For Jerseys, estimated maximum yields per hectare of milkfat and milk solids were at 4.45 and 4.37 cows/ha and were 686 kg fat/ha and 1761 kg milk solids/ha; 4 and 13\% respectively less than produced by the Friesians stocked at 3.7 cows/ha. The superior production of the Friesians was due to their higher food conversion efficiency, not to the higher food intake.}, issn = {1176-5283}, author = {Nicol AM and Parratt AC} } @conference {39899, title = {Mineral nutrients in pasture species}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {135-138}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Where mineral deficiencies have characteristics clinical signs (eg. milk fever or hypocalcaemia) or necropsy findings (eg. white muscle disease) diagnosis is comparatively easy. However, many mineral deficiencies are characterised by poor growth or production which are non-specific signs that can be caused by many factors. In these instances a systematic approach is required to determine if a mineral deficiency is likely to be involved. This paper outlines such an approach which includes: Description of animal health problem including a comparison with target weights and production parameters. Deduction of likely causes using clinical signs, soil, climate, plant and management clues. Diagnosis using appropriate diagnostic tests. The best tests are animal response trials or analysis of animal tissue parameter levels which can be related to a production response. Choice and results of animal diagnostic tests must be considered in relation to what the sampled tissue represents (eg. mineral intake, storage site or where the element functions), and the limitations placed on the test by other factors (eg. effect of concurrent disease). The importance of sufficient sample numbers to reflect herd mineral status and selection of animals for sampling in a random manner is emphasised. Interpretation of results and advice should be based on epidemiological knowledge of the mineral deficiency and the economic benefits of mineral supplementation. The use of animal diagnostic tests to predict some mineral deficiencies (preventive medicine), especially in areas of marginal deficiency, is briefly discussed. Because of the complexity of some mineral deficiency problems a team approach involving farmer, agricultural adviser and veterinarian is recommended.}, issn = {1176-5283}, author = {Cornforth IS} } @conference {39876, title = {Ovarian activity in the Booroola x Romney ewe possessing a major gene influencing fecundity}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {33-36}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Prices paid at 6 sales for Perendale fleece wool assessed as having loose wool bulk values of 25 cm}, issn = {1176-5283}, author = {McNatty KP and Henderson KM and Lun S and Heath D and Kieboom L and Hudson N and Fannin J and Ball K and Smith P} } @conference {39875, title = {Ovarian inhibin: a hormone with potential to increase ovulation rate in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {29-32}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The Booroola F gene gives sheep breeders a unique method of rapidly increasing the prolificacy of their flocks. Research data indicate that on average, every ewe carrying the F gene will produce about 1 extra lamb at each lambing. Breed type need not be changed from those currently favoured as the F gene can be transmitted to any breed, firstly by a series of controlled backcrosses and then by identifying carrier sheep of the desired breed type. Management systems to cope with large increases in lamb drop need to be developed along with breeding programmes to predict more accurately the genotype of individual sheep. These management systems and breeding programmes must also incorporate a strong emphasis on the ability to rear triplet born lambs to a marketable size.}, issn = {1176-5283}, author = {Henderson KM and Franchimont P and Lecomte-Yerna MJ and Charlet-Renard CH and Hudson N and Ball K and McNatty KP} } @conference {39912, title = {Perennial ryegrass staggers research - an overview}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {181-184}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Defoliation patterns of sheep grazing a staggers-prone, ryegrass-dominant pasture were studied at Palmerston North during the 1982-83 summer-autumn period. The 0.4 ha pasture was grazed for 5 to 8 days each month from November to May by groups of 30 to 50 sheep. Herbage at dung patch sites present in January covered about 25\% of the pasture area and remained ungrazed until May. Urine-patch sites covered about 35\% (16 to 45\%) of the pasture area and although urine- patch herbage was grazed before other types, differences were detected within this category: the most recent urine-patches were defoliated sooner and to a greater extent than older ones. Ryegrass at interexcreta sites was defoliated less frequently and to a lesser extent than that at urine-patch sites, except for those interexcreta sites that also contained white clover. Concentrations of the ryegrass endophyte, Acremonium loliae were higher in live ryegrass sheath at urine-patch than at inter-excreta sites. The results are discussed in relation to the acquisition of neurotoxins by sheep.}, issn = {1176-5283}, author = {Mortimer PH and Young PW and di Menna ME} } @conference {39871, title = {Predicting parturition in the ewe from the pattern of uterine motility}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {15-18}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Shortened daylight hours have been shown to advance the onset of puberty in ewe lambs. In this experiment the pineal hormone melatonin was administered to mimic short days with the aim of advancing the onset of first oestrus in September-born ewe lambs. Treatments were; no melatonin in 10 ml saline drenched daily (control), 2 mg melatonin in 10 ml saline drenched daily and 435 mg of melatonin implanted subcutaneously, each on 2 start dates - February 17 and March 17. Fertile rams were introduced on March 10 and April 7 respectively. All ewes were killed on July 28 and foetal crown-rump lengths measured to estimate the date of conception. The mean dates of first tup in the early treatments were not statistically different (May 25, May 9 and May 13) but there was a difference between the control and implant in the estimated dates of conception (June 1 and May 17, P<0.05). In the late treatment the mean dates of first tup were June 2, May 16 and May 10 respectively (P<0.01). However this difference did not lead to a treatment difference in the estimated date of conception because the percentages conceiving to the first tup were 38, 80 and 21 respectively.}, issn = {1176-5283}, author = {Wolff JE and Dobbie PM} } @conference {39902, title = {The Prevention and Treatment of Trace Element Deficiencies in Sheep and Cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {147-150}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The association between selenium and milk production was investigated on 98 farms in the Rangitaiki Plains and Galatea Basin during the 1981-82 dairy season. Ten blood samples per herd from randomly selected cows were tested for selenium on 4 occasions through the season. Animal, farm management and trace element supplementation data were also collected. Mean herd selenium levels varied considerably and there was a statistically significant association between herds with low blood selenium and low milk production in terms of kilograms of milkfat per hectare. Selenium milk response trials were carried out in 7 dairy herds in the Rangitaiki Plains district in the 1982-83 dairy season. Half of each herd received injections of selenium each 2 months with the remaining animals acting as controls. In 1 herd additional copper and copper/selenium groups were included. Using Livestock Improvement Association production figures, positive milk volume and milkfat responses were shown to occur on 6 of the farms. On 2 farms volume responses were significant at the 5\% level. It was considered that selenium deficiency has a small effect on milk and milkfat production on farms in this district, but that this effect is mediated by other factors.}, issn = {1176-5283}, author = {Farquharson BC} } @conference {39878, title = {Price premiums for high-bulk Perendale wools}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {41-44}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Weaned lambs are often shorn but the limited research on the practice does not demonstrate a clear advantage. As the level of feeding used in some trails may have led to the variable results, experiments investigated the possibility of an interaction between feeding level and lamb shearing. Pasture allowances of 1 kg and 2 kg DM/lamb/d were offered to shorn and unshorn Romney or Coopworth wether and ewe lambs (19 to 28 kg initial live weight) in 2 autumn trials on rotationally grazed irrigated pasture. In the 105-day 1982 trial the shorn and unshorn lambs were grazed together but in the 55 day 1983 trail they were grazed separately. There was an interaction (P<0.01) in 1983 between feeding level and shearing for carcass weight where shorn lambs offered 1 kg DM pasture allowance produced carcasses which were 0.8 kg lighter than the 10.4 kg carcasses for unshorn lambs fed at the same level. Both shorn and unshorn lambs on 2 kg DM allowance produced 11.7 kg carcases. In 1982 shorn lambs had a 10 g/lamb/d faster live-weight gain and 0.5 kg heavier carcasses than unshorn lambs. Carcass weights were 10.6 kg and 12.8 kg at the 1 kg and 2 kg DM feed allowances. The lack of an interaction in 1982, when shorn and unshorn lambs grazed together, may have been caused by shearing inducing an increased appetite in shorn lambs which resulted in competition for feed with the unshorn lambs. In 1982 rates of live- weight gain were 66 and 102 g/lamb/d and in 1983 40 and 110 g/lamb/d from 1 kg and 2 kg DM allowances respectively. These experiments suggest that while lamb shearing may have some management advantages, carcass weights of shorn lambs may suffer if their growth rates are restricted by limited pasture supplies.}, issn = {1176-5283}, author = {Elliott KH} } @conference {39883, title = {The production characteristics of fitch (Mustella putorius)}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {61-62}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Results are presented from the first year of a 4-year grazing trial investigating the effects of stocking rate (3.75 and 4.49 cows/ha) and time of conservation, October (early), November (late), on dairy production at the Waimate West Demonstration Farm in South Taranaki. Both stocking rate and time of conservation had a significant (P<0.05) effect on milkfat yield/cow which resulted in large differences between treatments in terms of milkfat production/ha. At the low stocking rate, milkfat production/ha was 645 and 619 kg, and at the high stocking rate 642 and 705 kg for the respective early and late conservation treatments. These differences in animal performance are attributed to differences in pasture allowance in early lactation and to the proportion of dead matter in the pasture over summer and autumn. The proportion of stem in pasture had little direct effect on dairy production but over time it may have contributed to the pool of dead matter causing lower milkfat yields in summer and autumn. The adoption of a high stocking rate and late conservation policy maintained adequate pasture allowance (33 to 35 kg DM/cow/d) in early lactation and a sufficiently intensive grazing pressure in October and November to prepare pastures of low dead and high green content over summer and autumn.}, issn = {1176-5283}, author = {Giles KH} } @conference {39891, title = {Prospects for the stimulation of lactation and growth of ruminants by the administration of growth hormone and related molecules}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {91-98}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Diet selection from 2 swards (ryegrass and prairie grass) vertically stratified into 3 horizons (A, >6cm, B, 3 to 6 cm, C, 0 to 3 cm) was studied using oesophageally fistulated ewes in summer and autumn. Green grass leaf (GGL) contributed 68 to 97\% of diets, whilst pseudostem and dead material were rejected. Sward and dietary white clover contents were low in the sward and 0.1 to 4.9\% in the diet) and no selection for this component was evident. Defoliation of white clover appeared to be influenced by the vertical distribution of GGL. Green material distribution determined the horizons grazed. Sheep grazed horizon C of summer ryegrass pasture, where 95\% of GGL was found. In all other swards the surface canopy (>3 cm above ground level) was composed primarily of GGL (>30\%), and sheep grazed this horizon. Low apparent intake (21 g DM/kg live weight/d) was associated with the apparent need to penetrate the surface canopy to obtain GGL in summer ryegrass pasture.}, issn = {1176-5283}, author = {Davis SR and Bass JJ} } @conference {39868, title = {Recent progress and future prospects of the New Zealand Society of Animal Production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {1-6}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Ewes were inseminated in 1982 and 1983 at the second oestrus after synchronisation. They received fresh or frozen semen deposited once or twice, either into the cervix, blind in the vagina, onto the ovaries or into the uterine horn lumen. Very poor results occurred after ovarian insemination. More ewes lambed when inseminated with fresh compared to frozen semen, when inseminated twice rather than once, and for 1983, the ranking of insemination positions (best to worst) was intra-uterine, blind, cervix. Ewes lambing after insemination with frozen semen in 1982 produced fewer multiples than those inseminated with fresh semen. A single blind insemination of fresh semen gave a lambing rate (64\%) only slightly lower than for cervical deposition (69\%) and the intra-uterine technique performed well with both fresh and frozen sperm (83\% and 38\%, respectively). Both these techniques should be considered for artificial insemination.}, issn = {1176-5283}, author = {Smith JF} } @conference {39884, title = {Recent trends in conception rates and return patterns in AB herds and their effects on calving patterns}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {63-66}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The average milkfat test for groups of first Friesian x Jersey (FJ) cows in 9 Waikato herds was 4.68\%, ranging from 4.36\% to 5.46\%. Animals with 75\% Friesian breeding had an average test 0.05\% lower than their first cross contemporaries whereas those with 25\% Friesian breeding had an average test which was 0.25\% higher. Variation in colour and height at withers were not reliable indicators of an FJ animal{\textquoteright}s test. Regression analyses with records of sires{\textquoteright} progeny-tested by the New Zealand Dairy Board from 1961 to 1979 showed that each 1 unit increase in milkfat breeding index (BI) in Jerseys was associated with an increase of 0.85 units in milk BI. The comparable figure for Friesians was 0.55 milk BI units. Since 1961, the average milkfat BI of Jersey sires selected for further use has increased by 24 units (117 to 141) with an associated increase in milk BI of 14 units (114 to 128). Comparable changes for Friesian sires were 17 units (121 to 138) and 6 units (115 to 121). The average live weight at calving over 4 seasons at Ruakura for high BI Jerseys was 385 kg compared to 404 kg for {\textquoteright}AB{\textquoteright} Friesians. The concurrent increases in milk and milkfat BI{\textquoteright}s in the Jersey breed may have been associated with a greater increase in live weight than in the Friesian breed. Owners of herds of FJ cows need not expect substantial changes in milkfat test or live weight through the continued use of Friesian sires to produce replacement heifers.}, issn = {1176-5283}, author = {Macmillan KL and Taufa VK and Phillips P} } @conference {39898, title = {The relationship between New Zealand{\textquoteright}s geology and soils and trace elements deficiencies in grazing animals}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {125-134}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {In determining a mineral requirement an attempt is made to measure the minimum dietary intake of the mineral that is necessary to maintain health and the desired level of production. Two approaches can be used to determine mineral requirements: (a) observation from practical feeding studies where the animal{\textquoteright}s response is related to the dietary level of the mineral under investigation (b) by calculation using data obtained from mineral balance studies where the losses in the urine, faeces and sweat, together with the amounts absorbed, are measured with other investigations to determine the mineral uptake by body tissues and foetus and the amounts secreted in the milk.}, issn = {1176-5283}, author = {Fraser AJ} } @conference {39920, title = {Relationship of subcutaneous fat depth and weight changes induced by stocking rate of 4 lines of lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {215-218}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Live weights, carcass weights and GR measurements from 566 Coopworth lambs were used to retrospectively establish criteria that would have directed carcass production away from discounted grades into those receiving premium payments. Greatest financial returns would have been achieved by slaughtering lambs when they approached fatness limits, before penalties applied. When live weights were the only means of selection, returns were greater at weights that resulted in production of some carcasses penalised for fatness and/or heavy weights than at weights that avoided discounted grades.}, issn = {1176-5283}, author = {Bennett GL and Clarke JN and Rattray PV and MacLean KS} } @conference {39916, title = {Relationships between insulin-glucose status and carcass fat in lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {201-204}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Paired 7-rib roasts from heavy ram and wether lambs fed pelleted diets were evaluated by 70 United States lamb consumers. Forty of the 70 lamb consumers preferred rib roasts from wethers. The 40 consumers preferring meat from wethers listed milder flavours along with more tender and juicier meat as reasons for their selection. The 30 consumers who preferred meat from ram lambs did so because the roasts were less greasy and the more intense flavour was preferred. Therefore, differences in intensity of flavour between meat from rams and wethers did exist but lamb consumers were divided on their preference for a stronger or milder flavour.}, issn = {1176-5283}, author = {Munro JM and Geenty KG and Bickerstaffe R} } @conference {39926, title = {Relative performance of meat breeds of sheep in New Zealand and overseas}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {239-242}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A sheep breeding experiment at Woodlands Research Station consists of 5 self-contained Romney selection lines (closed in 1973). Four lines are selected respectively for dam{\textquoteright}s number of lambs born (dam NLB), 100-day weight, hogget fleece weight, and a production index in which all 3 traits are combined, while the fifth line is a randomly selected control. Back fat thickness was measured in the 1982 born ewe lamb progeny at approximately 8 and 14 months of age. Relative to the controls (back fat 6.3 mm) the dam NLB (5.0 mm) and the production index (4.8) lines had 20\% lower back fat depths (P<0.01) in May after variance adjustment for live-weight. The differences were slightly lower when measured in November. The fat thickness of the 100-day weight and hogget fleece weight line progeny were similar to the controls. The heritability of back fat depth adjusted for live weight by half-sib analysis was 0.28}, issn = {1176-5283}, author = {Clarke JN and Bennett GL and Kirton AH} } @conference {39897, title = {Relative priorities for feed between ewes and ewe hoggets in winter and spring: a modelling analysis}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {121-124}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Grazing animals obtain most of the mineral nutrients they require from pasture plants. Whilst a knowledge of plant composition alone is of limited value, it is one of a series of clues which can be used to help diagnose or predict animal mineral status. Factors which influence the concentration and availability of minerals in plants are summarised in an attempt to aid the interpretation of plant analyses.}, issn = {1176-5283}, author = {McCall DG} } @conference {39874, title = {Reproductive performance of ewe offspring from ewes immunised against steroid hormones}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {25-28}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The pattern of ovarian follicular development in Booroola x Romney ewes (6-7 y) with an ovulation-rate >/-3 (F+ ewes) differed from that in Booroola x Romney ewes (6-7 y) with an ovulation-rate <3 (++). The difference was not due to variations in the number of ovarian follicles (>/-1 mm diameter) or in the proportion of healthy follicles which were similar for both genotypes. It arose because follicles in F+ ewes produced oestradiol and reached maturity at a smaller diameter than in ++ ewes. During a prostaglandin induced follicle phase, the secretion rate of oestradiol from ovaries with 3 presumptive preovulatory follicles in F+ ewes was similar to that from ovaries with only 1 such follicle in ++ ewes. Moreover, the total number of granulosa cells (i.e. the oestrogen-secreting cells) in 3 preovulatory follicles from F+ ewes was similar to that in 1 such follicle in ++ ewes. In F+ ewes, the presumptive preovulatory follicles reached 4.6 }, issn = {1176-5283}, author = {Smith JF and MacLean KS and McGowan LT and Potts IR} } @conference {39889, title = {The research potential of shared information resources}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {83-86}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Genetic engineering of micro-organisms to produce mammalian protein hormones promises to make the hormonal treatment of ruminants for the stimulation of lactation, growth and wool growth commercially viable. Treatment of lactating dairy cows with growth hormone (GH) commonly elevates milk production by about 4 kg milk/d. In growing beef and sheep GH increases nitrogen retention, reduces carcass fat content and may increase growth rate. Wool growth increases following the cessation of GH treatment. Many of the actions of growth hormone are likely mediated by a {\textquoteright}family{\textquoteright} of hormones, notably insulin-like growth factors I and II and epidermal growth factor. The efficacy of these materials in promoting production has not been investigated. Sustained-release implants have been developed which will deliver protein hormones over prolonged periods. However, the ability to promote production by direct manipulation of the animal genome may be the most economic approach. For example, injection of rat GH genes into fertilised mouse eggs resulted in mice that grew 2 to 4 times faster than normal.}, issn = {1176-5283}, author = {Wickham BW} } @conference {39887, title = {The salivary proteins secreted from cannulated parotid and mandibular glands of cattle after pharmacological stimulation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {75-78}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Recent developments in the technology for storing, retrieving and communicating data have lead to the possibility of greatly expanded data sharing. The advantages of extended data sharing in the animal based industries of New Zealand include the possibility of conducting research studies previously considered not feasible because of the resources required to collect and collate the needed data. With the sharing of information between farms, Government agencies, research institutions, servicing organisations and advisory services, it is possible to foresee research studies of considerable benefit to the primary industries in New Zealand. This paper will examine the concept of shared information and provide illustrations from the New Zealand Industry of the research potential.}, issn = {1176-5283}, author = {McIntosh JT and McLaren RD and Howe GW and Cockrem FRM and Carr DH} } @conference {39882, title = {Seasonal wool production and staple strength of Romney ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {57-60}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The average conception rate (CR) to first insemination in 1969- 70 was 60.6\% compared to 67.7\% in 1982-83. CR declined with increasing herd size in the latter study (from 70.5\% in herds of <101 cows to 66.0\% in herds of >300 cows), but this trend was substantially less than the former study (from 62.8\% to 52.3\%). The change in herd size effects was mainly due to improved accuracy in the detection of oestrus in larger herds probably associated with the use of tail paint. On average, 50\% of cows in 35 Waikato herds had calved by the end of a period of 18.3 d from the date of planned start of calving. The next 25\% of cows calved over a period of 17.5 d, and the last 25\% calved over 36.3 d. Consequently, the average calving covered 71.9 d from the planned start compared to 46 d in the Ruakura No.2 herd. A comparison with results from a 1972 survey showed that calving patterns had become more concentrated because of improved breeding management and the use of induced calving.}, issn = {1176-5283}, author = {Geenty KG and Orwin DFG and Woods JL and Young SR and Smith MC} } @conference {39928, title = {Selection for productive traits on back fat depth in ewe lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {249-252}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied.}, issn = {1176-5283}, author = {McEwan JC and Fennessy PF and Clarke JN and Hickey SM and Knowler MA} } @conference {39905, title = {Sodium requirements of grazing livestock}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {155-158}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Experiments were conducted for monthly periods during the spring and summer and autumn of 1982-83 with lambs fed on pastures from limed (pH 6.1) and unlimed (pH 5.5) areas. Lambs were offered herbage allowances 1, 2, 3, 4 or 5 kg DM/d on both limed and unlimed areas (10 groups of 10 lambs). Pasture composition remained similar between the 2 areas as did in vitro digestibilities of the pasture on offer. Limed pasture showed an increase in Ca and Mo and a decrease in Mn compared with the unlimed. Lamb live-weight gains were similar between limed and unlimed groups at all levels of herbage allowance over the 3 seasons suggesting that herbage quantity rather than quality was the major factor affecting the growth rate of the animals.}, issn = {1176-5283}, author = {Towers NR and Young PW and Smeaton DC} } @conference {39888, title = {Some rumen characteristics and performance data of cows differing in bloat susceptibility}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {79-82}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {This paper reviews some of the recent developments in genetic and embryonic engineering and attempts to assess their likely impact on animal breeding theory and genetic improvement programmes. The distinction is made between genetic and embryonic engineering.}, issn = {1176-5283}, author = {Carruthers VR} } @conference {39896, title = {Spring-summer grazing management on hill country: effects on ewe performance}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {117-120}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The soil type is an important factor influencing the occurrence of trace element deficiencies in grazing animals in New Zealand. Cobalt and selenium deficiencies occur mainly on soils from acidic rocks. Cobalt deficiencies may also occur on soils from more basic parent materials where the soils have been strongly leached. Selenium deficiencies is less easily predicted on the basis of soil characteristics. Copper deficiencies are more likely in stock grazing on peat soils, gley soils, certain pumice soils, saline soils, recent soils and some steepland soils. For all 3 elements, classification of occurrences of deficiency by soil type has provided a basis for delineating areas where deficiencies are likely, areas where they are unlikely and areas of marginal status. This has enabled a rational approach to investigations and the application of treatment and control measures.}, issn = {1176-5283}, author = {Smeaton DC and Wadams TK and MacKisack BD and Winter RD and Miller CM and Hockey H-UP} } @conference {39892, title = {Sward conditions, herbage allowance and animal production: an evaluation of research results}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {99-104}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Sixteen kids, 16 lambs and 16 calves approximately 4 months of age were allocated at random in balanced groups of 4 per species at a common allowance to 4 herbage masses (1800, 3000, 3900 and 5000 kgDM/ha) on a ryegrass white clover sward. A further calf, lamb and kid and a mature goat and ewe, fitted with oesophageal fistulas, grazed continuously with their own species at each herbage mass during the 8 day trial. These fistulated animals were randomly relocated to herbage masses every 2 days so that individuals sampled each herbage mass. On similar swards the diet of the lamb contained a greater proportion of clover (+0.23) and a smaller proportion of grass (-0.19) and dead material (-0.03) than the calf. The diet of the kid was intermediate between that of the lamb and the calf. The extent of dietary overlap suggests the species are in a major way competitive rather than complementary when grazing intensively managed swards. While older goats consumed a diet similar in composition to the young goat, older sheep consumed more dead material than lambs, although the proportions concerned were small. There was no difference in the in vitro digestibility of the diet selected by young goats, lambs and calves even though there were differences in botanical composition of the diet selected among the species. The in vitro digestibility of the diet selected was not affected by age of animal.}, issn = {1176-5283}, author = {Hodgson J} } @conference {39869, title = {Synchronisation and artificial insemination of ewes - techniques which have possible commercial application}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {7-10}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Mature ewes, 110 to 125 days pregnant, had catheters surgically implanted into maternal and foetal blood vessels and electrodes sutured to the myometrium. Electromyographic (EMG) signals were amplified, rectified, integrated and recorded. Between 2 and 12 days before parturition, the EMG pattern comprised bursts of activity that lasted 6.3 }, issn = {1176-5283}, author = {Harvey TG and Johnson DL and Tervit HR and Welch RAS} } @conference {39911, title = {Terminal sire comparisons of the Charolais and Murray Grey breeds for calving difficulty, calf survival and growth}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {177-180}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {An enzyme-linked immunosorbent assay (ELISA) system has been developed for the detection of an endophytic fungus of Lolium perenne. The technique has been used to demonstrate quantitative differences in the spatial and tissue distribution of the endophyte in vegetative and reproductive tillers of infected plants. The influence of this on pasture toxicity is discussed. The nature of the endophyte antigen is described and the relationship between the antigen and toxicity discussed.}, issn = {1176-5283}, author = {Morris CA and Baker RL and Wilson JA} } @conference {39915, title = {Theoretical considerations for partitioning nutrients between muscle and adipose tissue}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {193-200}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Calorimetry apparatus was used to measure CO2 production and oxygen consumption in 2 Romney and 2 Southdown ewes. Each pair consisted of a long-lean ewe and a short-fat ewe as determined from previous records of height, length, weight and ultrasonic back fat thickness. The respiratory exchange ratio (RER) was calculated as the ratio of CO2 produced/d to O2 consumed/d. When the 4 ewes were fed, the RER remained about 1, characteristic of the oxidation of glucose and short chain fatty acids. When the ewes were fasted for 4 to 5 days the RER declined in a straight linear fashion with time. This is consistent with the mobilisation of long chain fatty acids. The ewes of fatter genotypes exhibited significantly steeper regressions of RER on time.}, issn = {1176-5283}, author = {Waghorn GC and Wolff JE} } @conference {39903, title = {Trace element deficiencies - a new approach to diagnosis}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {151-152}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Responses to sodium supplements have been recorded in trials with weaner Angus calves and mature ewes grazing pastures containing Na concentrations exceeding the minimum dietary levels calculated from recent Agricultural Research Council (1980) recommendations. Increased live-weight gains were noted following supplementation of calves grazing pastures with a Na content of 1 g/kg DM, and in ewes on pasture with 0.7 g/kg DM. These results suggest that either the estimates of daily Na requirements are too low or that for Na availability is too high.}, issn = {1176-5283}, author = {Wright DF and Clark RG and Millar KR and Rowland JD} } @conference {39886, title = {Variations in milkfat test, liveweight, colour and height associated with the use of Friesian sires in some New Zealand dairy herds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {71-74}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Sixteen high (HS) and 16 low (LS) bloat susceptible dairy cows were offered hay or pasture when not lactating and pasture or 75\% pasture 25\% hay when lactating. There were no significant differences between susceptibility groups in voluntary intake or apparent digestibility of DM, OM, nitrogen or energy on either occasion. There was a trend for HS cows to produce less milk of higher fat, protein and lactose content than LS cows. Rumen digesta studies on 5 HS and 5 LS rumen-fistulated, dry, pregnant cows at a maintenance level of feeding indicated that the proportion of digesta lost from the rumen after feeding was higher for LS cows than HS cows on pasture, but not on hay. There was no significant difference between susceptibilities in post-feeding fluid dilution rate. HS cows tended to have higher rumen fluid osmolality and Na concentration during the post-feeding period on pasture, but not on hay.}, issn = {1176-5283}, author = {Macmillan KL and Henderson HV and Bryant AM} } @conference {39908, title = {Voluntary intake, testes development and antler growth patterns of male red deer under a manipulated photoperiod}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {167-170}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Two experiments studied the effects of herbage allowance in the latter half of pregnancy on the performance of 18-month beef heifers. In Experiment 1, 54 heifers were offered daily allowances of 4.5 (H) or 3.3 (M1) kg DM/100 kg live weight (LW), and in Experiment 2, 64 heifers were offered 3.1 (M2) or 1.9 (L) kg DM/100 kg LW. Average daily gain to post-calving weight (net ADG) for the H and M1 heifers in Experiment 1 was 0.46 and 0.34 kg/d (P<0.001). The post- partum anoestrous interval (PPAI) was short in both groups (H+ 42.7 and M1 = 49.2 days; P<0.10). H calves were 1.8 kg heavier at birth and 7.6 kg heavier at weaning than M1 calves (P<0.05). In Experiment 2, M2 and L heifer net ADG was 0.23 and -0.03 kg/d respectively (P<0.001). The PPAI was 28.4 d shorter for M2 than L heifers (P<0.001). Birth and weaning weights of M2 calves were heavier by 1.8 kg (P<0.07) and 14.0 kg (P<0.05) respectively than those of L calves. Results suggest that a herbage allowance of around 3 kg DM/100 kg LW over the latter half of gestation may be adequate for satisfactory performance of yearling-mated heifers.}, issn = {1176-5283}, author = {Suttie JM and Corson ID and Fennessy PF} } @conference {39808, title = {Animal Research - time for a new approach}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {1-6}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {In each of 2 years Coopworth ewes were randomised to 8 groups which were offered 2 levels of herbage allowance (1.0 and 5.0 kg DM/ewe/d) from mixed pasture for varying periods during the 6 weeks prior to a synchronised mating. The ovulation rates of ewes fed at the lower allowance and then given the higher allowance for periods of 1 or 2 weeks prior to mating were not different from those fed continuously at the lower allowance. Ewes offered 3 weeks at the higher allowance showed a 25\% increase in ovulation rate irrespective of when in the 6 week period this was received. Thus a minimum carry over period of 3 weeks was obtained. A further 30\% increase in ovulation rate was obtained when ewes were offered the higher allowance for the full 6 week period. The proportion in ovulation rate was obtained when ewes were offered the higher allowance for the full 6 week period. The proportion of ewes lambing multiples was lower for those receiving <3 weeks high level feeding than for those receiving at least 3 weeks (33.5\% v 56.0\%; P<0.001), but there was no additional response to feeding at the high level for 6 weeks.}, issn = {1176-5283}, author = {Fennessy PF} } @conference {39851, title = {Behaviour factors influencing the rearing of Sahiwal-cross calves}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {171-174}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The basic technique for freezing cattle, sheep and goat embryos is briefly described. The number of offspring born from each transferred thawed embryo is usually satisfactory but extensive pre and post freezing culling of embryos means that the technique is usually inefficient compared with unfrozen embryos. Research to improve results continues and the 54 and 64\% embryo survival/embryo frozen obtained from minimally selected sheep embryos at Ruakura is most encouraging. The technique is being used for the international export of cattle embryos. Its major advantage is that it enables the export of genetic material which could not otherwise be obtained by the importing country. Its use should increase as embryo survival rates increase and particularly if it is established as an effective means of infectious disease control.}, issn = {1176-5283}, author = {Ward JDB and Bremner KJ and Kilgour R} } @conference {39840, title = {Changes in the salivary sodium:potassium ratio in lactating cows in response to changes in sodium intake}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {131-134}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied}, issn = {1176-5283}, author = {Towers NR} } @conference {39835, title = {Comparison of well and poorly muscled lamb carcasses as selected by experienced meat industry personnel}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {111-114}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Ten lambs and 10 kids were offered a low quality meadow hay (7.1 gN/kg/DM) for 12 weeks. Five of each species were then reallocated to lucerne hay (23.8 gN/kg/DM) and the remainder maintained on meadow hay. Feed was offered ad libitum. Digestibility was determined at weeks, 4, 6, 10 and 16. Animals were fed at 2 h intervals prior to slaughter and the retention time of dry matter in the rumen estimated. Body energy changes were estimated by comparative slaughter. In the initial 6 weeks kids and lambs digested meadow hay to a similar extent but whereas it was maintained in kids, digestibility by lambs subsequently declined until week 16. At week 16 values for dry matter digestibility were 0.67 and 0.54 for kids and lambs, respectively. There were no significant differences in the digestibility of lucerne hay between the species nor in the voluntary intake of meadow hay or lucerne hay. Both species consumed more lucerne hay than meadow hay. Kids retained lucerne hay longer than did lambs (18.,7 h and 11.8 h, respectively) but meadow hay had a similar retention time in both species (24.7 h and 27.8 h, respectively). Water intake of lambs was approximately double that of kids. Difficulties in determining maintenance energy requirement from body weight change are discussed.}, issn = {1176-5283}, author = {Kirton AH and Woods EG and Duganzich DM} } @conference {39867, title = {Dags - cost thereof}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {231-232}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A number of facets of artificial insemination in sheep were studied at Rotomahana Research Station. The trial was a 2}, issn = {1176-5283}, author = {MacKereth VJ} } @conference {39819, title = {Date of lambing and sheep production during lactation in Southland}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {45-48}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {In a series of 10 trials involving over 5000 lactating dairy cows, animals inseminated when detected in oestrus from 3 days after an injection of a prostaglandin F2a (PGF) had an average pregnancy rate of 68\% compared to 59\% in untreated herdmates. The variation in the post injection interval to oestrus necessitated detecting oestrus before the PGF-related fertility effect could be repeatedly demonstrated. When a synthetic analogue of gonadotrophin releasing hormone (GnRH) was injected before PGF in an attempt to reduce the variation in this injection-to-oestrus interval, the opposite effect occurred, the average interval was increased by 3 days (4.13 v 7.03) and the PGF-related fertility effect was eliminated. A second trial with GnRH confirmed that an injection of this hormone had an effect on the corpus luteum which prevented complete luteolysis by PGF. This interaction between GnRH and the corpus luteum was studied in 3 further trials in which GnRH was injected once at from 1 to 13 days post insemination. Positive fertility effects were observed in each trial, but they were not consistent. Nonetheless, the strategic use of these 2 types of hormones offer prospects for significantly increasing pregnancy rates to first insemination in lactating dairy cows.}, issn = {1176-5283}, author = {McEwan JC and Mathieson C and Hawker H} } @conference {39864, title = {Development of a performance test for the selection of rams having facial eczema-tolerate progeny}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {221-224}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied}, issn = {1176-5283}, author = {Towers NR and Meyer HH and Campbell AG and Southey CA} } @conference {39825, title = {Differences in the extent of mammary development between Jersey cows of high or low genetic merit - Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {71-72}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The effect of feed allowance (approximately 150 and 250 g green DM/kg live weight 0.75/d) and season (sampling at 12-week intervals) on objectively measured wool characteristics of Cheviot, Drysdale and Romney hoggets was examined. Improved feeding increased wool growth rate, fibre diameter and brightness. Feeding level did not affect fibre diameter variation, loose wool bulk or yellowness. Wool grew faster and was coarser during summer than during winter. Fibre diameter variation for the Cheviot and Romney was greatest in winter and least for the Drysdale in summer. There was no defined seasonal cycle for loose wool bulk. Colour indices were related to prevailing weather conditions. Maximum and minimum values for each characteristic were strongly correlated for fibre diameter and fibre diameter variation, weakly correlated for loose wool bulk and not consistently related for wool growth rate and colour indices.}, issn = {1176-5283}, author = {Davis SR and Hughson GA and Bryant AM} } @conference {39813, title = {Distribution of litter sizes within flocks at different levels of fecundity}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {25-28}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Hogget lamb mortality in the Waihora sheep improvement programme from 1970/80 has ranged from 18 to 35\% (mean = 24\%). Hogget lambs born during the 1981 and 1982 lambings were used to study the timing, magnitude and causes of lamb mortality. Mean mortality to weaning were 33\% and 28\% in each year. The distribution of deaths was similar in each of the periods: at birth, born alive but died by day 3 and died between day 4 and docking. Dystocia was the single largest cause of deaths to day 3 accounting for about 13 lamb/100 lambs born. Birth weight was an important factor in lamb deaths with an optimum range of 3.3 to 4.1 kg for minimum mortality.}, issn = {1176-5283}, author = {Davis GH and Kelly RW and Hanrahan JP and Rohloff RM} } @conference {39861, title = {Effect of antioxidants on the toxicity of the facial eczema toxin, sporidesmin, in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {209-212}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Zinc sulphate (0.35 g Zn/litre) in the drinking water of lactating dairy cows prevented the effects of both a mild natural spore challenge and the subsequent severe challenge of dosed sporidesmin. The changes recorded (serum gamma glutamyl transferase, liver and urinary bladder injury score, daily milk production and clinical and live weight changes) in the unprotected control group indicate considerable toxic injury whereas the changes in the group receiving zinc in drinking water were minimal indicating excellent protection. Water consumption records for the 2 groups did not indicate that the zinc treated water was substantially discriminated against.}, issn = {1176-5283}, author = {Munday R and Manns E and Mortimer PH} } @conference {39823, title = {The effect of breeding index on the performance of non-lactating Jersey cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {63-66}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied}, issn = {1176-5283}, author = {Bryant AM} } @conference {39827, title = {Effect of feeding and season on fleece characteristics of Cheviot, Drysdale and Romney hogget wool}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {79-82}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {About 4000 ewes born over 3 years to single sire matings were repeatedly scored for incidence and severity of dags. Dag scores were analysed for evidence of genetic variation and relationship to structural and performance characteristics. Perendales were found to have lowest incidence of dags followed by Booroola x Perendales, Booroola x Romneys and then Romneys and Border Leicester x Romney ewes. There was no relationship between dag score and either wool or body weight characteristics, either within or between breeds. Among progeny of 6 Romney strain, daughters of Ruakura High Fertility rams had substantially lower incidence with little variation among the rest. It is suggested that long-term selection for fertility in this line has reduced incidence of dags through improved utilisation of forage, possibly as a result of resistance to internal parasites. The mean heritability of dag score was 0.31 with a range of 0.13 to 0.60, indicating that selection would be effective in reducing the incidence of dags and their associated costs to farmers.}, issn = {1176-5283}, author = {Sumner RMW} } @conference {39822, title = {The effect of pre-mating injection of an analogue of gonadotrophin-releasing hormone (GnRH) on pregnancy rates to first insemination in dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {59-62}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The results of experiments with Friesian cows with breeding indices of 126 (HBI) or 102 (LBI) are presented. HBI cows produced an average of 153 kg milkfat/cow in the 1979 to 1981 lactations and LBI cows produced 125 kg milkfat/cow. HBI cows lost 0.7 of a condition score during lactation whereas LBI cows maintained their condition score. In 2 of the 4 staff feeding experiments the dry matter intake of pasture/kg 0.75 was significantly higher for HBI cows than LBI cows. There were no differences between the 2 groups of cows in their ability to metabolise dietary energy, nor in their heat production. JBI cows partitioned a greater proportion of their dietary energy to milk energy than LBI cows. Blood samples taken hourly for 24 h periods from cows fed indoors were analysed for growth hormone, insulin, glucose, }, issn = {1176-5283}, author = {Fielden ED and Moller K} } @conference {39810, title = {The effect of the duration and timing of flushing on the ovulation rate of ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {13-16}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Matched groups of ewe hoggets were mated to either fertile Southdown rams or vasectomised rams for a 6-week period in 1980 and 1981. The percentage of Romney, Coopworth and Perendale hoggets born in 1979 showing oestrus were 82, 92 and 92, and for those born in 1980 47, 84 and 79 respectively. The lower incidence of oestrus in those born on 1980 can be partly explained by lower hogget pre-lambing weights related to an outbreak of facial eczema in April 1981. Of hoggets joined to fertile rams, the percentages that weaned a lamb were 47, 60 and 67 for those born in 1979, and 13, 53 and 52 for those born in 1980. The percentages of two-tooths joined that weaned a lamb (average for those born in 1979 and 1980) were 71 for those not tupped as hoggets, 74 for those tupped by vasectomised rams, 53 for those tupped by fertile rams but not lambing, and 76 for those lambing as hoggets. There was no suggestion that hogget lambing impaired two-tooth reproduction, but those lambing produced 0.15 kg less wool at the two-tooth pre-mating shearing. The April 1981 GGT level of the 1980-born ewes was inversely related to live weight in April through to September 1981, and to percentage of ewes lambing as hoggets and as two-tooths, and to two-tooth pre-mating fleece weight.}, issn = {1176-5283}, author = {Smith JF and Jagusch KT and Farquhar PA} } @conference {39838, title = {Effects of cold exposure on chewing behaviour and rumen particle size in sheep given 4 diets}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {123-126}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The rate at which the Na:K ratio of parotid saliva changes with changes in Na intake has been determined in lactating dairy cows. The salivary Na:K ratio of cows with an already marginal Na status fell immediately the animals were transferred to a Na deficient diet. Similarly the Na:K ratio of Na deficient cows incr3eased within days of Na supplementation reaching maximum levels after 2 weeks. The mean Na:K ratio for fully sodium replete cows was about 24 to 28:1, but there was considerable variation in the values for individual animals.}, issn = {1176-5283}, author = {Kennedy PM} } @conference {39811, title = {Effects of teasing and nutrition on the duration of the breeding season in Romney ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {17-20}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Proportions of ewes having 1 to 4 lambs in 72 local breed flocks with mean litter sizes per ewe ranging from 1.07 to 2.30 were examined, and compared with the proportions recorded in 12 groups of Booroola and 8 groups of Finn type ewes. Below a mean litter size of 1.70, differences in litter size resulted from differences in the proportion of ewes having singles and twins. Mean litter sizes ranging from 1.70 to 2.30 were accompanied by changes in the proportions of ewes having singles and triplets, the proportion of ewes having twins or quadruplets showing no significant change. The proportions recorded in local breed flocks and groups of Finn-type sheep were similar over litter sizes of 1.70 to 2.30. Groups of ewes that carried 1 copy of the Booroola gene had more ewes with 1, 3 and 4 lambs, but fewer ewes with twins, than the local breed flocks.}, issn = {1176-5283}, author = {Knight TW and Hall DRH and Wilson LD} } @conference {39865, title = {Ewe live weight, level of pasture feeding and live-weight gain}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {225-228}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The following farmer observations are based on limited numbers and are really a plea for more accurate work to be done. Loss from dags is difficult to cost but nationally it probably runs into millions in devalued wool and extra labour. On my own farm the direct loss is estimated to be about 63 cents/stock unit/annum. To reduce this loss I have looked at the following practices: 1. Breeding, limited observations - nil results. 2. Drenching. In two-tooths a drench pretupping reduced dags 44\% in a 3 month period. 3. Docking tails longer was inconclusive, possibly due to a limited difference between {\textquoteright}long{\textquoteright} and {\textquoteright}short{\textquoteright} tails. 4. Mules operation. Result a 50\% reducing between January and May. Mulesed sheep are easier to crutch by hand or machine. Sheep were apparently not knocked about by the operation. Although gory, mulesing is preferable to flystrike in terms of suffering. Uninformed and emotional public opinion is a problem. The greatest benefit of dag control or elimination may come from reduced flystrike.}, issn = {1176-5283}, author = {Thompson KF and McEwan JC and Kelly RW and Crosbie SF} } @conference {39853, title = {Export of animals as frozen embryos}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {179-182}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Reproduction was compared in 2, 13-month weight-selection herds, Hereford (HS1) and Angus (AS1), in an 18-month weight-selection Angus line (AS2) and in an unselected Angus control (AC0), with ages at first joining in both sexes being 14, 14, 26 and 26 months respectively. Pregnancy rates (all ages, 5453 joinings) averaged 86, 88 and 90 and 86\% respectively, so that yearling bull mating and/or weight selection have not disadvantaged the AS1 or AS2 lines. Sub-fertile bulls in the 3 selection lines numbered 5, 1 and 5 out of 59, 59 and 59 respectively. Calf death rates from 2-year-old AS1 heifers were lower than from 3- year-old first-calving AC0 heifers. The AS2 line weaned an adjusted total of 1005 calves (963, before adjusting by proportionally) from all age groups over 10 years, compared with 1239 calves in the AS1 line, a shortfall of 18.9\%.}, issn = {1176-5283}, author = {Tervit HR} } @conference {39826, title = {Fleece tenderness - a review}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {73-78}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The heritability of loose wool bulk and yellowness (CIE Tristimulus value Y-Z) and the genetic and phenotypic correlation of these with other wool traits were determined from data obtained on ewe hoggets born in 1979 and 1980 in the strains trial at Rotomahana. Heritability estimates were 0.41 }, issn = {1176-5283}, author = {Bigham ML and Sumner RMW and Hawker H and Fitzgerald JM} } @conference {39829, title = {Genetic variation in incidence of daggy sheep - an indicator of genetic resistance to parasites?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {87-90}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A recent grazing experiment at Ruakura with dairy cows involved in each of 3 years, 8 farms of 6.48 ha. Linear regression procedures were used to derive relationships between milkfat yield to 31 December, amount of feed on the farm at various times, length of rotation during winter months, and average herd live weight and condition at calving. Fat production was closely related to feed on the farm during July to September but not to feed present in May, June, October or November, or to live weight and condition at calving. The amount of feed present in August or September was not significantly related to that present in May. Feed present in September increased as the area grazed each day by the herd increased in May, and decreased in July and August. For a given amount of feed on the farm during July to September, early calving herds produced more milkfat per cow and per hectare by 31 December but at a lower level per day than late calving herds.}, issn = {1176-5283}, author = {Meyer HH and Harvey TG and Smeaton JE} } @conference {39859, title = {Genetic variation in uterine efficiency and differential responses to increased ovulation rate in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {201-204}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Four antioxidants - butylated hydroxytoluene (BHT), butylated hyroxyanisole (BHA), alpha-tocopherol and propyl gallate - have been tested for their ability to ameliorate the harmful effects of the facial eczema toxin, sporidesmin, in sheep. A moderate decrease in sporidesmin-induced liver damage (39\% and 35\% respectively, based on gross pathological assessment of liver injury) was observed in sheep pre-treated with BHT and BHA; smaller effects were recorded in animals receiving the other compounds. The possibility of an additive effect between antioxidants and zinc has also been investigated. It was shown that marked protection against sporidesmin toxicity, significantly greater than that given by either prophylactic alone, was afforded by simultaneous administration of BHT and zinc.}, issn = {1176-5283}, author = {Meyer HH and Clarke JN and Harvey TG and Malthus IC} } @conference {39850, title = {Growth and carcass composition of Sahiwal-cross and Friesian bulls}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {167-170}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Two experiments were carried out in controlled temperature rooms, with Brahman x Friesian (F) calves aged 6 to 9 months exposed to 34}, issn = {1176-5283}, author = {Reardon TF and Woods EG and Ward JDB and Bass JJ} } @conference {39828, title = {The heritability of loose wool bulk and colour traits and their genetic and phenotypic correlations with other wool traits}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {83-86}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Twelve dairy farmers were taught a system of pasture scoring in May 1981. From then until the start of calving they assessed the amount of feed on their farms at fortnightly intervals. Milkfat production per hectare during the subsequent season was closely related to the amount of feed on the farm at the start of calving. Feed at calving was closely related to the amount of feed on the farm in May. The data suggest that milkfat production from most dairy farms is limited by having insufficient feed on the farm at calving.}, issn = {1176-5283}, author = {Bigham ML and Meyer HH and Smeaton JE} } @conference {39815, title = {Hogget lamb mortality}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {33-36}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Dorset ewes rearing twin lambs were offered herbage allowances of 2, 5 and 8 kg DM/ewe/d during a 6-week lactation period. Ewes and lambs were shifted at 3-day intervals. At 6 weeks lambs were weaned, combined into 1 mob and offered a fresh area of pasture ad lib every 3 days. Lambs were slaughtered at 6, 12 and 18 weeks of age. Carcass weight and fat measurements recorded. There were significant live-weight differences (2.5 kg) between low and high allowances during the trial, but differences in carcass weight were only significant at 6 and 18 weeks. Average growth rate between 6 and 18 weeks was 176 g/d in all groups. Fat measurements suggested no differences in carcass fatness between groups. It was concluded that herbage allowance preweaning had little effect on subsequent lamb growth and carcass fatness when ewes were shifted to new pasture at 3-day intervals.}, issn = {1176-5283}, author = {McMillan WH} } @conference {39812, title = {Hogget lambing and its effect on the subsequent two-tooth performance of three breeds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {21-24}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Lamb survival and birth weight data from a Booroola x Romney flock and a Booroola x Merino flock were collected between 1975 and 1981. The mean litter sizes for these flocks were 1.96 and 1.76 respectively, with litter sizes ranging from 1 to 4 within each flock. Effects of year, ewe age, birth rank and birth weight on lamb survival were assessed by fitting a sequence of logit models to the data. Birth weight was identified as the key parameter, with year and birth rank effects being markedly reduced once the variability due to birth weight was accounted for. An apparent ewe age effect was completely explained in terms of lamb birth weight. At any given birth weight lambs born to large litters (>/-3) had a lower probability of survival than contemporary lambs born as singles or twins.}, issn = {1176-5283}, author = {Moore RW and Sumner RMW and Bass JJ and Hockey H-UP} } @conference {39830, title = {The importance of the amount of feed on the farm at calving to seasonal milk production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {91-92}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A simple stocking rate model was used to derive stocking rates that maximise milkfat/ha and profit/ha. A study of recent changes in the cost/price structure indicates that economically optimal stocking rates are determined mainly by the parameters of the milkfat/cow- stocking rate relationship and are relatively insensitive to even large changes in the cost/price structure. Farmers{\textquoteright} options of holding costs and adjusting stocking rates are discussed. Finally, an example is used to demonstrate the use of the method with research data and to illustrate factors worth considering in designing and interpreting trials to assess the value of a management input. Future trials should be run at stocking rates designed to describe production-stocking rate relationships rather than to accentuate treatment differences}, issn = {1176-5283}, author = {Phillips TI} } @conference {39854, title = {The improvement and export potential of Bali cattle (Bos bibos-banteng)}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {183-184}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Teeth wear over a 12-month period was measured in young ewes of 9 Romney and crossbred genotypes. Animals of Border Leicester breeding had higher-than-average wear rates and Merino-derived animals showed lowest wear. Genetic variation among genotypes and sires within genotypes accounted for the majority of explainable variation in wear rate. The pooled heritability estimate for teeth wear was 0.46 }, issn = {1176-5283}, author = {Packard PM} } @conference {39821, title = {Increasing pregnancy rates in New Zealand dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {53-58}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Data from 4 experiments involving comparisons of cows of high (HBI) and low (LBI) breeding index summarised. In 2 stall feeding experiments, the differences (H-L) in daily intake (kg DM/100 kg LW) were -0.08 }, issn = {1176-5283}, author = {Macmillan KL and Taufa VK} } @conference {39817, title = {Influence of herbage allowance during the suckling period on subsequent growth and carcass fatness of twin lambs weaned at 6 weeks of age}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {41-42}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The effects of date of lambing (6 September, 23 September, 6 October) and rearing category (singles, twins) on ewe and lamb live weights and ewe wool production were examined in 1981 and 1982. Later lambing increased lamb growth in the first 6 weeks of lactation from 208 to 279 g/head/d for singles and 135 to 215 g/head/d for twins (P<0.001). Lambing date did not significantly affect lamb live weights at weaning on 5 January. Later lambing increased ewe greasy wool production between June and January by up to 0.41 kg (P<0.001).}, issn = {1176-5283}, author = {Munro JM and Geenty KG} } @conference {39856, title = {Inheritance of wear rate in the teeth of sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {189-192}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Ovulation rate records from female progeny of 3 Booroola-type rams and the daughters of 8 to 10 male progeny of the same rams were recorded in commercial flocks. When a segregation criterion of at least 1 record of ovulation rate >/-3 was used to identify carriers of the putative gene, the results support the hypothesis of genetic segregation for fecundity in Booroola sheep. A comparison of the genotype ascertained from progeny tests with that estimated from the parental genotypes showed that 21 of 22 rams{\textquoteright} performance was consistent with a single gene effect.}, issn = {1176-5283}, author = {Meyer HH and Aitken WM and Smeaton JE} } @conference {39837, title = {Intake, digestibility and retention time of 2 forages by kids and lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {119-122}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Fifty New Zealand Romney lambs (25 wethers and 25 ewes) grazing a ryegrass/white clover pasture from weaning, were used to study the distribution of zinc, copper, manganese and iron among the various organs and tissues and the amounts associated with a kilogram gain in fleece-free empty body weight. Each kilogram gain in fleece-free empty body weight was associated with 24 mg Zn, 0.77 mg Cu, 0.47 mg Mn and 55 mg Fe, while a kilogram of clean wool contained 220 mg Zn, 7 mg Cu, 3.5 mg Mn and 23 mg Fe. Thus for a young sheep gaining 100g of fleece-free empty body weight/d maintaining a mean wool growth of 10 g/d the daily demands for Zn, Cu and Mn for growth (2.4 mg Zn; 0.08 mg Cu; 0.05 mg Mn) and wool production (2.2 mg Zn; 0.07 mg Cu; 0.035 mg Mn) were found to be similar.}, issn = {1176-5283}, author = {Alam MR and Poppi DP and Sykes AR} } @conference {39834, title = {Integrating livestock and sugar-ethanol production and the dairy industry in Northland - a concept}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {107-110}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Suffolk and Southdown rams were selected on the basis of high (H) and low (L) ultrasonic fat depths over the loin, adjusted for live weight. Rams were mated to Romney ewes and progeny were slaughtered at 2 ages. Loin fat depth (C) adjusted for carcass weight by 0.31 }, issn = {1176-5283}, author = {Piggot GJ} } @conference {39866, title = {Large scale live breeding sheep exports- Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {229-230}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied}, issn = {1176-5283}, author = {Tavendale JB} } @conference {39846, title = {Livestock exports: animal health implications}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {151-154}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {There is a dearth of useful performance data on exported New Zealand-bred animals. Expectations vary as to what is required of these animals and breed comparison trials involving them in foreign environments are rare. Care must be taken to avoid the {\textquoteright}bigger is better{\textquoteright} syndrome in judging the performance of exports. New Zealand genotypes adapt to foreign temperate environments and perform according to level of management. New Zealand dairy cattle, pigs and poultry can perform well in tropical environments if managed intensively. Crossbreeding between imported and local, adapted genotypes of cattle and sheep would seem to be the best way to use New Zealand germplasm in tropical countries. The use of Zebu semen on New Zealand cows to produce tropically adapted crossbreds for export is proving successful but such cattle are unlikely to outproduce exotic x local crossbreds. There is a need for information to enable better choice of breeds for crossbreeding and the development of breeding plans to enable importing countries to make best use of exotic genes.}, issn = {1176-5283}, author = {Schwarz G} } @conference {39844, title = {Livestock exports: exporter{\textquoteright}s viewpoint}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {145-146}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The role of the Animal Health Division of the Ministry of Agriculture and Fisheries in the export of animals is outlined. New Zealand{\textquoteright}s freedom from serious animal diseases and the high quality of its livestock are the major factors contributing to the steady overseas demand for animals. The animal health conditions of importation are variable and often require considerable negotiation before they are acceptable to both New Zealand and the importing country. Veterinary officers have a dual role - to -protect the importer and to assist the exporter and there has to be constant liaison and cooperation at all levels to ensure a successful fulfilment of export orders. Animal welfare is a major consideration at all stages of the operation.}, issn = {1176-5283}, author = {Wallace RD} } @conference {39847, title = {Livestock exports: national economic significance}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {155-158}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Much of the non-arable area of South Korea is suited to the establishment of permanent improved pasture. In 1974 the New Zealand Government began a co-operative project to establish a pasture based beef cattle farm on 354 ha in the alpine region of South Korea. Two hundred Hereford and Angus breeding stock were sent from New Zealand to form the foundation herd for the project. The pr9oject{\textquoteright}s extension programme included 25 private farms. Permanent pastures comprising perennial ryegrass, cocksfoot, timothy, white and alsike clovers were successfully established following the fencing and mobstocking of scrub with the application of fertiliser. New Zealand cattle showed superior growth rates to native cattle in the temperate climate. No major disease problems were encountered. Continuous grazing during the 6 months of pasture growth and the conservation of surplus pasture as hay or silage for winter provided adequate nutrition for the spring calving herd.}, issn = {1176-5283}, author = {Gould MD and Baigent PN} } @conference {39842, title = {Livestock exports: past present future}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {137-140}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied}, issn = {1176-5283}, author = {Callow AV} } @conference {39845, title = {Livestock exports: the advisors{\textquoteright} and farmers{\textquoteright} view}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {147-150}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {At least 6 different species of animals are currently being exported from New Zealand, horses, cattle, sheep, goats, pigs and poultry. Of theses only horses, cattle and sheep are of economic significance. Although the volume and value of livestock exports has increased dramatically in percentage terms over recent years, returns from total livestock exports still amount to less than 1\% of total exports. It is anticipated that dairy cattle exports in particular could continue to increase in geometric terms. Scope also exists for increased exports of other species but they will be subject to more constraints. While livestock exports are useful in a national economic sense and are important to individuals, companies and some geographic areas, it is unlikely that they will amount to any national economic significance in the foreseeable future. It is unlikely that livestock exports will adversely affect overseas markets for New Zealand animal products. Rather, the resulting expansion in local production is likely to stimulate consumption, leading to consumer pressure to increase imports to satisfy this demand.}, issn = {1176-5283}, author = {Dawson JE} } @conference {39843, title = {Livestock exports: the role of the thoroughbred}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {141-144}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The types and economics of each contract for export animals are discussed and examined from the advisers{\textquoteright} and farmers{\textquoteright} view. The good returns in 1982 for rearing of qualifying Friesian heifers calves are indicated together with the various margins for Sahiwal options. Data is presented from a survey which has shown an adoption rate for the Sahiwal scheme of 22\% with 66\% of adopters continuing with it. Reasons for non-adoption are discussed, as are also industry considerations of this recent and developing market, particularly those affecting dairy processing and the domestic market for dairy heifers.}, issn = {1176-5283}, author = {Hogan P} } @conference {39818, title = {A low cost method of artificially rearing lambs at pasture}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {43-44}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A Poll Dorset flock was mated naturally in spring for 4 years. As lambing date shifted from mid June to mid April overall flock fertility declined but fecundity did not change greatly. Ewes lambing in mid April were under less feed stress during lactation than ewes lambing in late May. Integration of the flock with spring lambing ewes was made easier with a more concentrated lambing pattern in autumn. As lambing date changed from 24 May to 12 April, lamb growth rates in winter declined. However, more than 84\% of the lambs reached 30 kg live weight by mid November. High faecal egg counts were recorded in April born lambs before weaning.}, issn = {1176-5283}, author = {Smith MC and Geenty KG} } @conference {39849, title = {The management of New Zealand beef cattle exported to South Korea}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {163-166}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Davis GH and Lewis KHC and Matheson DE} } @conference {39816, title = {Nutrition and management of ewes before and after lambing}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {37-40}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Lambs were offered low (180g DM/d) or high (320 g DM/d) allowances of cold ewe milk replacer until they reached live weights of 9 or 12 kg. Growth performance before and after weaning was compared with that of single-suckled lambs weaned at the 2 corresponding live weights. Growth rates of lambs offered a high milk allowance were greater than for those offered a low allowance and were similar to those for suckled lambs. Low milk allowance groups showed a relatively smaller growth check following weaning. The major factor affecting post weaning live weights was weaning weight; lambs weaned at 9 kg weighed, on average, 18.4, 24.9, 34.8 and 42.5 kg respectively at 12 weeks, 18 weeks, 12 months and 15 months of age and those weaned at 12 kg weighed 20.3, 27.1, 36.3 and 44.7 kg at the corresponding ages. It was concluded that the use of cold ewe-milk replacer and the encouragement of lambs to consume herbage at an early age provided a low cost, low labour method of artificially rearing lambs.}, issn = {1176-5283}, author = {Smeaton DC and Rattray PV and MacKisack B and Heath S and Hockey H-UP} } @conference {39824, title = {Nutritional and physiological studies of differences between Friesian cows of high and low genetic merit}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {67-70}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Fleece tenderness is a serious fault of New Zealand crossbred wool costing the sheep industry between $50 and $100 million annually. Wool fibres break at the point where fibre diameter is at its minimum and factors which influence minimum fibre diameter will influence the incidence of fleece tenderness, e.g. breed and strain of sheep, age of ewe, level of feeding and reproductive status. Tender fleeces are on average lighter than sound fleeces and often have other associated faults such as cotting and yellow discolouration. Variation in minimum winter fibre diameter accounts for only about 40\% of the variation in staple strength within a flock suggesting that factors other than fibre diameter may be involved. There are fibre structural and compositional differences between sound and tender wools of the same diameter and these may be associated with fleece tenderness. The wool producer can influence the incidence of fleece tenderness by the level of feeding during mid pregnancy but it may not always be economic to feed better. Choice of shearing time will also influence the level of fleece tenderness. A preliminary estimate of the heritability of fleece tenderness of 0.58 }, issn = {1176-5283}, author = {Davey AWF and Grainger C and MacKenzie DDS and Flux DS and Wilson GF and Brookes IM and Holmes CW} } @conference {39814, title = {Patterns of lamb survival in high fecundity Booroola flocks}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {29-32}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {In Trial 1, ewes were fed high or low nutrition in mid and late pregnancy and post lambing until docking in a 2}, issn = {1176-5283}, author = {Hinch GN and Kelly RW and Owens JL and Crosbie SF} } @conference {39820, title = {Performance of an autumn lambing Poll Dorset flock in Northland}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {49-52}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Seven trials were conducted during 3 breeding seasons where half the animals in each trial herd received a subcutaneous injection of 10}, issn = {1176-5283}, author = {Andrewes WGK} } @conference {39848, title = {Performance of New Zealand-bred animals in foreign environments}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {159-162}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Growth rates of Sahiwal-cross (S x F) and Friesian (F) bulls were compared in 2 experiments. In the first, 40 F and 38 S x F bulls were slaughtered at a carcass weight of about 230 kg and the left side of each carcass was jointed and dissected into meat, fat and bone. The 2 breed groups were grazed at equal levels of pasture allowance from 17 weeks of age when F calves (124 kg) were 30 kg heavier than S X F. After 17 weeks of age, F bulls gained live weight and carcass weight faster than S X F and were slaughtered 9 weeks earlier. Mean weights of carcass, of carcass corrected for live weight and of fore- and hindquarters, were the same for the 2 breeds. However, S x F carcasses had more meat (72\% v 71\%), more fat (8\% v 6\%), less bone (20\% v 22\%) and consequently a higher meat:bone ratio (3.55 v 3.18) than F carcasses of the same weight. In the second experiment 24 F and 24 S-cross bull calves were grazed as 1 mob from 20 weeks of age when both breeds had a mean live weight of 96 kg. From then until 55 weeks of age F and S-cross bulls grew at similar rates (0.59 and 0.56 kg/d respectively). From 55 to 67 weeks, F bulls grew slightly faster (1.26 and 1.18 kg/d respectively).}, issn = {1176-5283}, author = {Quartermain AR} } @conference {39839, title = {Quantities of zinc, copper, manganese and iron associated with body weight gain and wool growth of young sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {127-130}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied}, issn = {1176-5283}, author = {Grace ND} } @conference {39809, title = {Ram induced stimulation of ovarian and oestrous activity in anoestrous ewes - a review}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {7-12}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Seventy-nine Romney ewes were allocated to high (H) or low (L) pasture allowances from 27 January. Half of each group (R) was joined with teaser rams on 9 February while the other half (I) remained isolated from rams until 10 March. R ewes exhibited oestrus 13 days earlier than the I ewes but there was no effect of nutrition. L ewes had fewer oestruses than H ewes (7 v9) and more abnormal oestrous intervals (16\% v 7\%). There was a negative relationship between number of oestruses and GGT levels and a positive relationship with live weight. There was no effect of teasing on the number of oestruses, thus R ewes returned to anoestrus 16 days earlier than I ewes. Similarly L ewes returned to anoestrus 20 days earlier than H ewes.}, issn = {1176-5283}, author = {Knight TW} } @conference {39831, title = {Relationships between amount of feed on the farm, autumn-winter grazing management and dairy cow performance}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {93-96}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A selection experiment which has resulted in dairy cows of extremes susceptibility to bloat is reviewed. The low susceptibility cows had a higher liquid milk production and a lower milkfat percentage than the high susceptible ones. They showed little or no bloat on highly potent pastures. Comparison of the herds was directed towards physiological differences and relationships which could explain the origin of low susceptibility and lead to phenotypic definition useful for selection. Some differences were found in proportions of salivary proteins and progress has been made in their separation, definition and measurement. In vitro experiments have not indicated sufficient differences in gas or foam production per litre of rumen fluid to explain bloat grade variation but observation followed by direct experiment has shown that a greater volume of rumen fluid is associate4d with a high susceptibility to bloat. This could form a basis for commercial selection if appropriate measurement methods can be devised.}, issn = {1176-5283}, author = {Bryant AM and MacDonald KA} } @conference {39858, title = {Segregation of a major gene influencing ovulation rate in progeny of Booroola sheep in commercial and research flocks}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {197-200}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Superovulation with ova transfer (1979, 1980) and superovulation (without ova transfer) plus artificial rearing (1981, 1982) were used to establish flocks of Romney, Perendale and Coopworth sheep from fecund animals donated by farmers. In their first and second years respectively in the ova transfer programme, 39\% and 32\% of donor ewes failed to have any progeny by ova transfer, and 38\% and 44\% failed to lamb themselves while the mean number of lambs tailed per donor at joining was 2.68 and 2.21. In their first and second years respectively in the artificial rearing programme only 7\% and 3\% of ewes failed to produce a lamb with a mean number of lambs born per donor joined of 2.15 and 2.36. High lamb mortality rates (27\% and 32\% of lambs born) resulted in 1.58 and 1.64 lambs tailed/ewe/annum. About 40\% of ewes failed to reach the objective of at least 2 live lambs/ewe/annum in both programmes.}, issn = {1176-5283}, author = {Davis GH and Kelly RW} } @conference {39857, title = {Selection efficiency in ram breeding flocks}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {193-196}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Genetic variation in ovulation rate, both within and between breeds, is recognised as a major source of variation in litter size, while breed differences in embryonic survival are generally assumed to be unimportant. Results reported here for several trials, years and locations and involving large numbers of naturally multiple ovulating ewes show significant and consistent genetic differences in the proportion of ewes producing 2 lambs following conception to twin ovulations (uterine efficiency). Compared to contemporary Romneys (uterine efficiency = 0.59), 4 to 34\% more ewes of 5 other genotypes produced twin lambs following conception to twin ovulations. At the extreme, Border Leicester x Romneys ranged from 24 to 52\% superior in 3 comparisons. At ovulation rates higher than 2, inter-ovarian ovulation pattern was also found to influence litter size. Increasing disproportionality of ovulation rate between ovaries resulted in lower litter size. This may be due to uneven distribution of implantation sites and increased losses due to crowding.}, issn = {1176-5283}, author = {Dodd CJ and Delahunty JR} } @conference {39833, title = {Selection for and against susceptibility to bloat in dairy cows - a review}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {101-106}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Experienced meat industry personnel selected lamb carcasses categorised as either well muscled, average muscled or poorly muscled, so that a more objective specification of the carcasses meeting these different descriptions might be made. Well muscled carcasses were found at the blocky (E) end and poorly muscled carcasses toward the middle (Av) of the MLC conformation scale. Poorly muscled carcasses had the longest F, T, cut-leg length, carcass length and M. longissimus dorsi length measurements when compared at similar weights with the other muscling classes. Well muscled carcasses tended to have the highest fat percentage and lowest bone content. There was no difference in muscle content between carcasses of the different muscling types. This ability to recognise muscle content in lamb carcasses may explain the absence of a premium from the meat industry for carcasses with a higher muscle content despite consumer research suggesting that more muscle and less fat is required.}, issn = {1176-5283}, author = {Cockrem FRM and McIntosh JT and McLaren R} } @conference {39852, title = {Some effects of hot conditions on Brahman or Sahiwal crossbred calves}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {175-178}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {New Zealand is involved in the improvement of the Bali breed of cattle in Indonesia through a bilateral aid project. From 1977/82 significant improvement has been achieved in the Bali Cattle Development Project - 5 kg, 6 kg and 22 kg improvement in weaning, yearling and rising 2-year-old live weights respectively and 21\% improvement in calving percentage. Establishment of a central breeding herd of elite Bali cows is planned with top performance and progeny tested bulls being made available to the local farmers through artificial breeding. The unique qualities of Bali cattle enhances its export potential throughout many tropical and subtropical countries of South-East Asia and the Pacific.}, issn = {1176-5283}, author = {Holmes CW and Hughes TP and King CG and Sauwa PEL and Auko PSA} } @conference {39862, title = {Sporidesmin concentrations in the bile of sheep resistant or susceptible to sporidesmin dosing}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {213-216}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A practical performance test identifying rams siring progeny with greater than average tolerance to sporidesmin-induced liver damage (facial eczema) has been developed. The performance test, which can be conducted under field conditions using toxic pasture as the challenge, depends on measuring elevations in plasma gamma glutamyltransferase levels as a non-destructive way of assessing sporidesmin-induced liver damage. Selection for tolerance to facial eczema in commercial flocks is now feasible. Trial results indicate rapid responses to selection can be expected.}, issn = {1176-5283}, author = {Fairclough RJ and Smith BL} } @conference {39832, title = {Stocking rate effects in dairying}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {97-100}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Arising from agronomic research into energy farming in Northland, a sugar-ethanol industry based on the crop sweet sorghum (Sorghum bicolor) has been proposed. The competitiveness of such an industry will probably depend on an integration with the processing functions of the dairy industry, and on the advantages gained from the increased animal production resulting from utilising the sugar-extracted crop residues. A theoretical analyses of dairy, sheep, and fattening beef systems indicated that a limit of 10\% of the farm cropped in sweet sorghum annually would optimise the production and use of sugar-extracted crop residues based on the use of most of the residues as silage. If such material could be converted directly to increase stocking rate, a substantial rise in net farm income was predicted from growing sweet sorghum for sugar. Twenty Northland farmers were interviewed concerning on-farm aspects of this sugar industry concept. While limited in scope, this survey indicated a number of factors influencing further development of the concept, such as the importance of cropping contractors and independent technical advisors, and the doubt concerning the expected response from feeding crop residues to livestock.}, issn = {1176-5283}, author = {Wright DF and Pringle RM} } @conference {39860, title = {Techniques to establish flocks from fecund ewes by superovulation with and without ova transfer}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {205-208}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Twelve ram lambs bred for resistance or susceptibility to sporidesmin dosing were operated on under general anaesthetic and T-way catheters inserted into the common bile duct to facilitate collection of bile. After a recovery period of 14 days the animals were given an oral dose of sporidesmin at a rate of 0.08 mg/kg/d over 3 consecutive days. A trace amount of 35S-labelled sporidesmin was also given on the first and third day of dosing to allow quantitation of sporidesmin appearing in the bile fluid. Bile samples were collected at 0.5 to 1 hourly intervals for 24 hours after the first and third dosing. Results showed bile concentrations of sporidesmin increasing to a maximum in 1 to 3 hours and then declining over the following 20 hours. There was considerable individual variation among animals in the pattern of uptake and in the maximal concentration reached after dosing. In some animals there was a marked increase in biliary sporidesmin from the first to the third oral dosing while other animals showed little observed increase at these times. A positive correlation (P<0.05) was found between liver- damage score at slaughter and maximum sporidesmin concentration in bile after the third but not the first oral dosing. These findings raise the possibility that an initial or {\textquoteright}potentiating{\textquoteright} dose of sporidesmin may be required before {\textquoteright}susceptibility{\textquoteright} or {\textquoteright} resistance{\textquoteright} to facial eczema is expressed.}, issn = {1176-5283}, author = {Kelly RW and Lewer RP and Allison AJ and Paterson A and Howarth M} } @conference {39855, title = {Ten years reproduction performance data from Angus and Hereford weight selection herds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {185-188}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A sheep selection efficiency analysis developed to supplement recording on Sheeplan was applied to performance records in 8 groups- breeding scheme central flocks. Average flock size was 756 ewes, and 170 rams were selected from 4 birth-years for central flock use. Selection efficiencies for the Sheeplan two-tooth index were 64\%, 74\%, 70\% and 68\% for rams born in 1977/80 and the corresponding efficiencies for two-tooth ewes were 29\%, 27\%, 42\% and 44\% respectively. The selection of two-tooth ram and ewe replacements is expected to result in annual rates of improvement of 0.67\% in lambing rate, 0.16 kg in weaning weight, 0.34 kg in hogget live weight and 0.029 kg in hogget fleece weight. Other traits breeders emphasised included structural soundness, wool quality and hogget lambing performance. Opportunities for increasing rates of progress in sire breeding programmes are discussed.}, issn = {1176-5283}, author = {Morris CA and Baker RL and Hunter JC} } @conference {39836, title = {Ultrasonic selection for divergence in loin fat depth in Southdowns and Suffolks}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {115-118}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The physical breakdown of 4 forage diets in the chopped or pelleted form was studied in 16 closely-shorn wether sheep at room temperatures of approximately 24}, issn = {1176-5283}, author = {Bennett GL and Meyer HH and Kirton AH} } @conference {39841, title = {The use of {\textquoteright}Lipiodol{\textquoteright} for sub-clinical iodine deficiency in livestock - Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {135-136}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Over the 11-year period 170/81, the number of thoroughbred mares being bred from approximately doubled (4874 to 9894). This dramatic upsurge in the broodmare population cannot be accounted for by increased fertility, which has remained at approximately 72\% since the early 1950s. Rather it reflects the apparent lack of culling taking place of genetically (progeny tested) inferior mares. Unlike other agriculture enterprises, where increased production is dependent upon increased numbers, the thoroughbred industry sells on a {\textquoteright}quality{\textquoteright} rather than a {\textquoteright}quantity{\textquoteright} image and over-production of inferior grade animals can be harmful. The success of the {\textquoteright}quality{\textquoteright} image can be gauged by an excess of export earnings over imports in the order of $25m in the year ended 30 June 1982 ($29m exports, $4m imports). The exports were achieved by the sale of nearly 1800 thoroughbred stock to 12 overseas countries. The factors considered important in the production of {\textquoteright}quality{\textquoteright} thoroughbred stock are: rigorous culling of non-commercial breeding stock; sound nutrition; yearling preparation techniques; reduction in fertility wastage of genetically superior stock; sound nutrition; yearling preparation techniques; reduction in fertility wastage of genetically superior stock; disease control; overseas promotion. The development of a New Zealand equine industry with a potential annual export earning capacity in excess of $100m will depend on these factors together with Government assistance in the area of export incentives, research in mare fertility, nutritional imbalances in young thoroughbreds and pasture management.}, issn = {1176-5283}, author = {McGowan AC} } @conference {39863, title = {Zinc sulphate in the drinking water of lactating dairy cows for facial eczema control}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {43}, year = {1983}, month = {Jan}, pages = {217-220}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The live-weight response of light and heavy ewes to a range of pasture allowances was investigated in 3 experiments. Differential feeding levels prior to the commencement of Expt. 1 generated light and heavy ewes (52 v 57 kg live weight, P<0.001; 3.5 v 4.1 body condition score, P<0.01) that were subsequently offered pasture allowances of either 1, 2 or 4 kg DM/ewe/d for a 10-week period. Light ewes gained more weight than heavy ewes on all allowances. With time, ewes tended to approach a constant live weight in equilibrium with their level of feeding. Both light and heavy ewes harvested pasture to similar post- grazing residuals and rejected the dead material in the sward. In Expts, 2 and 3 low and high live weight ewes were selected from within large flocks of 4-tooth ewes that had been run as 1 mob (live weight 38 v 49 kg Expt. 2, 41 v 55 kg Expt. 3, P<0.001; body condition 1.8 v 2.4 Expt 2, 2.1 v 3.1 Expt, 3, P<0.01). Light and heavy groups were most grazed separately on allowances of 1.2 or 4 kg DM/ewe/d for 6 weeks although Expt. 3 partly comprised mixed groups for assessment of competition effects. No such effects were apparent on the higher allowance where light and heavy ewes had similar live-weight gains. On the lower allowance however, light ewes were more responsive than their heavier counterparts with this being less pronounced under mixed grazing. The implications for flock management are discussed.}, issn = {1176-5283}, author = {Smith BL and Embling PP and Pearce MG} } @conference {39802, title = {Animal production from hill country: Effect of fertiliser and grazing management}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {173-176}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {In each of 2 years mixed age Coopworth ewes (1978, 58 kg; 1979, 55 kg) were randomised immediately before lambing and offered a range of herbage allowances (2, 4, 6, 8 and 10 kg DM ewe) from mixed pasture of contrasting mass (1978, 2300 v 4140; 1979, 2100 v 3600 kg/ha) and lucerne (1978, 4390 kg/ha; 1979, 3000 kg/ha) until weaning at 10 weeks post-lambing. Final ewe weight, weight change, weight of lamb weaned per ewe and ewe fleece weight all increased with allowance. Lamb weaning weights started to level off above 8 kg DM/ewe but ewe gains and fleece weight continued to increase. On the higher-mass pasture ewes were lighter in 1978 and lambs were lighter in 1979. Lucerne-fed ewes lost more weight and produced less wool, but had similar (1978) or heavier (1979) lambs at weaning than pasture-fed ewes. The importance of feeding during lactation on lamb weaning weight was highlighted and management implications discussed.}, issn = {1176-5283}, author = {Clark DA and Lambert MG} } @conference {39795, title = {An approach to advisory work with deer farmers in Southland - Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {153-154}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied}, issn = {1176-5283}, author = {Harbord MW} } @conference {39779, title = {Biochemical events associated with Ficoll washing of ram spermatozoa}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {95-98}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Changes in meat processing to comply with overseas and domestic hygiene requirements or to reduce costs and improve product quality are almost continuous. Electrical stunning, mechanical dressing, accelerated conditioning, shrink wrapping and further processing are discussed in relation to their impact for producers. Major meat processing changes that could affect either processing costs or increase the gross return for the products and thereby affect the return to producers are considered. Some of these changes require producers to modify their management practices to get the increased returns.}, issn = {1176-5283}, author = {Jansen GJ and van Eerten MTW and Forrester IT} } @conference {39799, title = {Blood plasma tryptophan concentration - a potentially useful indicator of feed intake in pasture-fed ruminants - Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {165-166}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Mixed perennial ryegrass (Lolium perenne L.) and white clover (Trifolium repens L.) pastures at Ruakura were sprayed with Mefluidide, a herbage growth retardant, in 3 consecutive spring periods from 1978. Pasture DM yields was markedly depressed at rates as low as 0.2 kg ai/ha and the effects were more marked with early season applications than those applied in late season. Mefluidide reduced the incidence of Poa annua L. in the swards and white clover was increased. In 1979/80, weaned lambs were set stocked on pastures sprayed with Mefluidide at 0.2 kg ai./ha. Live-weight gain/head was increased at each of 3 levels of pasture on offer. Pastures again contained less Poa annua and more white clover. In 1980/1 pastures were sprayed with Mefluidide at 0.2 kg ai/ha Ethofumesate at 0.2 kg ai/ha to eliminate clovers. Lamb gain was again increased on pastures sprayed with Mefluidide although 1 month after application fewer animals were carried at equivalent levels of herbage offer, due to lower herbage growth rates. It is concluded that Mefluidide enhances the herbage quality of perennial ryegrass/white clover pasture and that the technique has special application where per head performance is of paramount importance.}, issn = {1176-5283}, author = {Davis SR and Hughson GA and McLeay LM} } @conference {39771, title = {Calving behaviour of single-suckled Angus cows and their calves born in the spring}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {69-72}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Oversowing and top-dressing of a small area within a defined but unfenced part of a high country summer range caused sheep to concentrate on that treated area. Sheep density and grazing pressure were respectively 4 and 7 times greater than on the untreated area. As fewer sheep grazed the untreated area dry matter utilisation overall decreased in the following 2 years.}, issn = {1176-5283}, author = {Aitken VR and Holmes RJ and Barton RA} } @conference {39756, title = {Central nervous system injury as a determinant of lamb mortality}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {15-18}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The aim of the present study was to establish whether ovulation and normal corpus luteum function could be induced in anoestrous ewes by supplementing the endogenous level of luteinizing hormone (LH) and whether cyclical ovarian activity could be induced and maintained in seasonally anoestrous ewes by an unvarying long-term intravenous pulse regime of gonadotrophic releasing hormone (GnRH), 500 ng once per 2 h or 43-80 days. The results demonstrated that a normal ovulation can be induced in anoestrous ewes with LH alone and that the aforementioned GnRH regime was successful in inducing cyclical progesterone activity. These findings suggest that normal breeding activity may be restored to anoestrous ewes when the frequency of hypothalamic GnRH is increased from an apparent endogenous level of secretory episode per 3.5 h to 1 episode per 2 h.}, issn = {1176-5283}, author = {Duff XJ and McCutcheon SN and McDonald MF} } @conference {39757, title = {Characteristics of high performance flocks in Otago and Southland - Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {19-20}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Marshall Romney ewes had higher ovulation rates and percentage births than control Romney ewes. These differences were accounted for by the higher live weights of Marshall Romney ewes. Differential grazing in 1979 produced ewes with different condition scores and live weight but the same body size. Ovulation rates were higher in the heavier ewes with the higher condition score. Body size and condition score contributed approximately equally to the variation in the live weight and both accounted for a significant proportion of variation in ovulation rate. However live weight accounted for more of the variation in ovulation rate than body size and/or condition score.}, issn = {1176-5283}, author = {Rohloff RM and Davis GH and Hinch GN} } @conference {39789, title = {Chemical and histological parameters associated with the tenderness of hemicastrate and steer beef}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {131-132}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The fat thickness over the 12th rib was measured ultrasonically on 41 Coopworth ram lambs (7 months of age, 34 to 57 kg live weight). Four of the 7 fattest and 4 of the 7 leanest were selected on the basis of their deviations from the overall fat thickness - live-weight relationship. Ten to 12 male progeny of each of these rams generated from Perendale ewes were slaughtered at 4 to 7 months of age and 4 parameters of carcass fatness measured. The difference between the progeny of the 4 lean sires and that of the 4 fat sires was significant for 2 fat measurements, namely C (P<0.05) the backfat thickness over the 12th rib, and S2 (P<0.01) a fat depth in the shoulder region. Differences in GR and total chemical fat failed to reach significance. The data indicate that selection of sires on the basis of backfat thickness could be an effective means of reducing carcass fat thickness in lambs.}, issn = {1176-5283}, author = {Hinch GN and Thwaites CJ} } @conference {39785, title = {Comparison of backfat depth probes for use in pig carcass grading}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {119-120}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Objective measurements in cattle accounted for a significant percentage of the variation of hindquarter muscle weight after adjustment for weight of hindquarter and within the N.Z. export P grade. The conformation measurements on lamb accounted for only a small percentage of the variation of the weight of muscle and fat-free frozen carcass weight. Objective conformation measurements in cattle may be of use in a grading system unlike the conformation measurements taken in sheep.}, issn = {1176-5283}, author = {Adam JL and Duganzich DM and Hargreaves K} } @conference {39784, title = {A comparison of the composition and carcass quality of Kelly and Russian castrate, ram, wether and ewe lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {117-118}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Data on M. longissimus dorsi (LD) area, width and depth were examined on 1957 lamb carcasses graded for export as either P (moderate to heavy fat cover) or Y (light fat cover) over 3 slaughter seasons. Lambs were sired by 1 of 11 different breeds mated to Romney ewes. Carcasses in the 2 grades differed in mean weight and LD measurements in the different seasons. After adjustment for differences in carcass weight and the effect of sire breed, LD area did not differ between the P and the Y grades. After adjusting the A (width) and B (depth) measurements of differences in carcass weight and sire breed, P grade LD{\textquoteright}s were significantly narrower and deeper than those from the Y grade, but the differences were small (maximum of 5\% for depth in 1970/1 season) and of little practical significance. Thus if the leaner Y grade carcasses are desired, and this is done on a within breed basis, the LD area or shape should not be adversely affected provided carcass weights are not reduced.}, issn = {1176-5283}, author = {Kirton AH and Clarke JN and Hickey SM} } @conference {39796, title = {Diet selection by goats and sheep on hill country}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {155-158}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Diet quality was measured using oesophageally-fistulated lactating Dorset ewes offered herbage allowances of 8 (H), 5 (M) and 2 (L) kg DM/ewe/d. Ewes on all allowances tended to have a similar selection preference for grass and clover; those on H and M allowances consumed proportionately more clover and less dead material than L ewes. The mean DDM of herbage selected by ewes in H and M groups averaged 0.790 and was 0.734 for L ewes compared with 0.727 for sward samples taken pre-grazing. The ME content of DM consumed by H and M ewes was 7\% greater than for L ewes. It is suggested that the lower digestibility of the diets of L ewes was due to a higher consumption of dead material and plant stalk than in ewes on H and M allowances.}, issn = {1176-5283}, author = {Clark DA and Lambert MG and Rolston MP and Dymock N} } @conference {39786, title = {Differences between P and Y export lamb carcass grades in M. longissimus dorsi area and shape}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {121-124}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Fat depths were measured on the hot carcasses of 128 pigs, 64 steers and 106 lambs using an appropriate Fat-Depth Indicator (FDI). Corresponding linear depths were taken 4 cm (pigs), 8 cm (steers) and 3.5 cm (lambs) lateral to the dorsal midline in the region of last rib. Pig and steer carcasses were physically dissected into subcutaneous fat plus rind and trim fat respectively. Of fat depths taken on the hot carcass by FDI 72, 57 and 98\% were within }, issn = {1176-5283}, author = {Kirton AH} } @conference {39770, title = {Differences in grazing and milking behaviour in high and low breeding index cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {65-68}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Groups of Merino lambs, with or without their mothers, were exposed to whole grain wheat for periods ranging from 5 to 45 hours at different ages before weaning at 10 weeks. Acceptance of wheat was tested during the following week. Feeding behaviour was monitored during exposure periods and both behaviour and intake were recorded during 30 minute test periods on each of 5 days in week 11. Groups of lambs exposed together with their mothers, which regularly ate wheat, all ate; their intakes averaged 810 g/head over the test period. Another group, also exposed with their mothers, but mothers which had been first offered wheat during the week before exposure, all ate wheat; their intakes averaged 290 g/head. Most lambs exposed without their mothers ate very little or no wheat in the post-weaning test period. The results show that pre-weaning experiences, particularly those related to maternal or other adult influences, are strong determinants of feeding behaviour, at least in the short term. Post-weaning acceptance of wheat was not obviously affected by age when exposed, duration of exposure, or interval from exposure to testing. The practical implications of these results are discussed.}, issn = {1176-5283}, author = {Arave CW and Kilgour R} } @conference {39772, title = {Early feeding experience and subsequent acceptance of feed by sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {73-76}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The effects of an extra {\textquoteright}flush{\textquoteright} of pasture around mating v recommended pasture allowance levels for beef cows after calving through mating were compared in 1979 and 1980 on cows which had been fed to maintain live weight from 8 weeks prior to and up to calving. Cow live weight after calving was positively associated with increasing feed levels although the differences were small to non-significant by weaning. There were no reproductive responses to feeding better than the allowance of 10 kg DM/cow/d from calving to mating and 16 kg DM/cow/d thereafter to weaning. Cows fed 16 kg Dm/cow/d had a higher pregnancy rate (100 v 90\%) than those fed 12 kg DM from calving to mating regardless of flushing treatment in 1979.; More reliable reductions in interval to first oestrus can probably be achieved by delaying calving date. Treatment had no effect on calf weight at weaning.}, issn = {1176-5283}, author = {Keogh RG and Lynch JJ} } @conference {39806, title = {The effect of clean pasture and anthelmintic frequency on growth rates of lambs on irrigated pasture - Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {187-188}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied}, issn = {1176-5283}, author = {McAnulty RW and Clark VR and Sykes AR} } @conference {39763, title = {The effect of early nutrition and hogget oestrus on subsequent reproduction}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {41-44}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The performance of ~400 Waihora Romney x Romney (W x R) F1 ewes born in both 1977 and 1978, and ~150 W x R B1 ewes born in both 1979 and 1980, was compared with that of similar numbers of contemporary commercial Romney (R) ewes. At hogget shearing W x R ewes were generally heavier (range minus 0.2 to plus 3.9 kg) than R ewes, with fleece weights differing by minus 0.15 to plus 0.26 kg. As two-tooths W x R ewes were 1.0 to 2.9 kg heavier than heavier than R ewes, with 7 to 12 more ovulations per 100 ewes and 1 to 5\% fewer lamb deaths, producing 10 to 15\% more lambs tailed per ewe joined. More W x R wether lambs were drafted fat than R wether lambs (1979/80 - 77 v 60\%; 1980/1 - 98\% v 86\%).}, issn = {1176-5283}, author = {Moore RW and Hockey H-UP} } @conference {39761, title = {Effect of ewe ovulation rate and uterine efficiency on breed and strain variation in litter size}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {33-36}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Two experiments investigated the relationship between growth rate, hogget oestrus and subsequent reproduction. In Experiment 1 there were increases in the proportion of two-tooth ewes ovulating multiples due to high plane rearing from late December to mid July or the presence of hogget oestrus, after the correction of two-tooth pre-mating live weight. None of the four-tooth lambing differences due to rearing or hogget oestrus was significant after correction for two-tooth pre-mating live weight. There were no significant differences due to any factor at the six-tooth lambing. In Experiment 2 there was an increase in the proportion of two-tooth ewes twinning due to the presence of hogget oestrus after correction for two-tooth pre-mating weight. There were significant effects of hogget oestrus on four-tooth twinning rates, before but not after, correction for two-tooth pre-mating live weight. There were no significant effects on twinning at the six-tooth lambing.}, issn = {1176-5283}, author = {Meyer HH and Clarke JN} } @conference {39801, title = {The effect of Mefluidide on pasture and animal performance}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {169-172}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {With high quality herbage from irrigated Nui ryegrass and Huia white clover pastures, supplemented with Matua prairie grass pasture, realised herbage allowances were considerably lower than current recommendations. Allowances were calculated from herbage on offer in a 10-paddock rotational grazed system, with no adjustment being made for herbage grown during the grazing period, and with grazing always to a residue of less than 300 kg DM/ha. An allowance of 1.7 kg DM/ewe/d at flushing provided for a live-weight gain of 3.3 kg over a 6 week period, an allowance of 2.35 kg DM/ewe/d during 90 days lactation supported twin lambs at a growth rate of 230 g/d; an allowance of 1.32 kg DM/d for weaned lambs supported a growth rate of 129 g/d during summer. These results were achieved in self-contained farmlets, with annual herbage production of 14 500 kg DM/ha, stocked with high fertility Coopworth ewes at 22/ha, and calculated to yield 670 kg lamb meat/ha (193\% lambs surviving to sale at 33.0 kg live weight). Feed efficiency in this system reflects full utilisation of available herbage, thus never allowing dead material or seed heads to build up in the pasture.}, issn = {1176-5283}, author = {Goold GJ and Jagusch KT and Farquhar P and MacLean KS} } @conference {39792, title = {Effects of castrating and surgically dehorning male Drysdale and Tukidale lambs on the efficacy of mechanical head skinning}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {141-144}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied}, issn = {1176-5283}, author = {Sumner RMW and Longdill GR} } @conference {39797, title = {Effects of chewing during eating on particle size reduction and subsequent fermentation in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {159-160}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied}, issn = {1176-5283}, author = {Ulyatt MJ and Reid CSW and Carr DH} } @conference {39807, title = {The effects of drenching regimen and pasture larval contamination on gastrointestinal parasitism of lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {189-192}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The stimulation of oestrus in ewes early in the breeding season has been known for a number of years but only recently has there been a full understanding of the changes which occur in the ewe. Recent work indicates that only 17 to 21 days isolation from rams is needed to sensitise ewes to the ram. Within 10 minutes of introducing rams, the luteinising hormone (LH) levels increase in the ewe. This can result in a preovulatory LH surge 27 to 35 hours later and a silent ovulation within 54 to 72 hours in anovular ewes. However, 43 to 59\% of ewes have a premature regression of the corpus luteum (CL) and a second silent ovulation occurs 4 to 6 days later. This leads to flocks have peaks of first oestrus around days 18 and 24 after ram introduction. Injection of progesterone at ram introduction prevents premature regression of the CL and first oestrus is synchronised over days 19 to 21 after ram introduction. The percentage of multiple ovulations is higher at the silent ovulation than at the first oestrus or in spontaneously ovulating flock mates. Priming with progestagens for 12 to 16 days can induce oestrus at the first ovulation after ram introduction and still maintain the increased proportion of multiple ovulations. The ram effect is due to pheromones which are present in the ram{\textquoteright}s wool and wax. The buck is as effective as the ram at stimulating ewes and fatty acid pheromones isolated from the buck are also effective at stimulating ewes.}, issn = {1176-5283}, author = {Thompson KF and Risk WH and Mason PC and Crosbie S} } @conference {39805, title = {Effects of season and pasture allowance on the wool growth of Romney ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {183-186}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The minimal drenching recommendations for lambs of the N.Z. Society of Animal Production Study Group (2 or 3 drenches) were compared with 5 and 12 fortnightly drench regimens on safe (low larval count) and contaminated (high larval count) pastures. Lambs grazing safe pastures had lower (P<0.05) gastrointestinal worm burdens than lambs grazing contaminated pastures, and increased drenching frequency significantly reduced (P<0.01) the average faecal egg count. The minimal drenching regimen did not adequately control parasitism in lambs. Increasing the number of drenches improved parasite control and increased wool and live-weight production.}, issn = {1176-5283}, author = {Hawker H and Crosbie SF and Thompson KF} } @conference {39790, title = {Evaluation of dam breeds and crosses for export lamb production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {133-136}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The effects of castrating and surgically dehorning male Drysdale and Tukidale lambs at birth or docking on subsequent horn growth were investigated in 3 lamb crops at Whatawhata Hill Country Research Station. Castration was more effective than dehorning in reducing subsequent horn growth. A combination of castration at birth and dehorning at docking was the most effective way to treat lambs to reduce horn growth. Excision of germative tissue around the base of the horn following dehorning increased the effectiveness of dehorning. Attainment of meat inspection standards for horned breeds is more dependent on the "trimmers" on the slaughter chain than the time of dehorning.}, issn = {1176-5283}, author = {Clarke JN and Atkins KD and Geenty KG and Johnson DL and Hickey SM and Wilson JA} } @conference {39788, title = {An evaluation of the fat-depth indicator on carcasses of pigs, cattle and sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {127-130}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Results from recent diallel crossbreeding experiments are used to illustrate the range in average genetic merit for meat and wool production available for utilisation in our present breed resources by crossbreeding. Performance of reciprocal first crosses suggests in addition considerable opportunity for exploitation of hybrid vigour. Breed differences are considerably reduced when production is expressed relative to ewe body size, although first-generation crosses remain superior to purebreds on this basis.}, issn = {1176-5283}, author = {Adam JL and Bass JJ and Kirton AH} } @conference {39783, title = {Factors controlling fat deposition in meat animals}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {113-116}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Depth of subcutaneous fat plus skin was measured by Fat Depth Indicator and Introscope on 95 {\textquoteright}backed down{\textquoteright} hot carcasses from entire males and gilts slaughtered at 70 and 90 kg live weight. Measurements were taken 4 and 6.5 cm lateral to dorsal midline immediately posterior to the last rib. Both probes predicted percentage fat with similar accuracy at the 4 cm site (rsd 2.4\%), but at 6.5 cm the Introscope was slightly the more accurate (rsd 2.3\%). Allowing for different sex intercepts improved the accuracy of predictions. Accuracy of predicting corresponding fat depths on the chilled carcass varied with probe and site. Linear regression relationships of Introscope of Fat-Depth Indicator fat depths gave residual standard deviations of 1.5 mm and 1.4 mm at the 4 and 6.5 cm sites respectively.}, issn = {1176-5283}, author = {Wood JD} } @conference {39777, title = {Fertility of inactivated bovine sperm}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {91-92}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A semen washing technique employing Ficoll density gradient centrifugation was used to separate ram spermatozoa and seminal plasma. While this technique caused a loss of spermatozoan motility, it was shown by CA2+ flux measurements that these immotile ram spermatozoa still had intact plasma membranes. Furthermore, these immotile spermatozoa were shown to be resistant to cold-shock, a treatment which normally disrupts the sperm plasma membrane. Spermatozoa were shown to be resistant to cold-shock, a treatment which normally disrupts the sperm plasma membrane. Spermatozoan motility was restored by suspending the immotile spermatozoa in diluents containing egg yolk or phospholipids. Ficoll washing appeared to exert its effect on the sperm plasma membrane by an alteration in the membrane lipid components.}, issn = {1176-5283}, author = {Shannon P and Curson B and Pitt CJ} } @conference {39778, title = {Fertility of inactivated ram sperm}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {93-94}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {With very few exceptions, consumers are becoming more discerning in their meat buying habits. This relates to such aspects as attractiveness of presentation, price, ease and quickness of preparation and cooking, degree of waste and fat content. The impact of these factors on consumption of red meat and red meat exports from New Zealand are examined with particular reference to response required from producers if they are to contribute effectively to maintain New Zealand{\textquoteright}s status as a premier export meat nation.}, issn = {1176-5283}, author = {Tervit HR and James RW and Shannon P and Tillot M} } @conference {39762, title = {Flushing responses of well and poorly reared two-tooth ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {37-40}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The effects on two-tooth reproduction of 3 times of shearing relative to joining either in early March or early April were investigated. Ewes were shorn either 4 or 2 weeks before joining or remained unshorn throughout. Ewe fertility was increased by shearing 4 weeks before joining compared with the other shearing treatments. Joining ewes in April increased fertility. It is concluded that ewes should be shorn at least 4 weeks before joining and joined in April rather than March if lamb production is to be maximised.}, issn = {1176-5283}, author = {Smeaton DC and Webby RW and Hockey H-UP and Wadams TK} } @conference {39803, title = {High animal production from low herbage allowance}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {177-178}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Wool growth responses of Romney ewes to increasing pasture allowance in the autumn (pre-joining), early winter (mid pregnancy) and spring (lactation) were examined. Live weight gain and wool growth increased curvilinearly with allowance. Wool growth responses were greater in autumn than winter, with spring intermediate. The maximum difference in clean fleece weight between extremes of pasture allowance was 0.41 to 0.12 kg for autumn, 0.12 kg for winter and 0.15 kg for spring. Changes in live-weight gain were associated with greater changes in wool growth in autumn than in winter or spring.}, issn = {1176-5283}, author = {Fraser TJ} } @conference {39758, title = {Induction of cyclical ovarian activity in seasonally anoestrous Romney ewes: studies with exogenous GnRH or LH}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {21-24}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Groups of high and low fecundity Booroola x Romney (B x R) and Romney (R) two-tooth ewes grazed a pasture containing 85\% {\textquoteright}Grasslands Pawera{\textquoteright} red clover for 10 days; similar groups of ewes grazed ryegrass- white clover control pastures. Oestrus and ovulation were synchronised in all ewes to occur during the last 5 days of grazing. Pawera leaf material contained 0.7\% formononetin and the pasture was highly oestrogenic to sheep (>40 }, issn = {1176-5283}, author = {McNatty KP and Ball K and Hudson N and Gibb M and Thurley DC} } @conference {39774, title = {The influence of an extra flush of pasture before and during mating on the performance of beef cows on hill country}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {79-82}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Two experiments involving 715 suckling beef cows were conducted to determine the effects of oestrogen treatment at the time of PRID insertion on the synchronisation of oestrus and conception rate to timed AI. Experiment 1 examined the route of administration and dose level of oestrogen while Experiment 2 studied the effect of oestrogen treatment at PRID insertion and/or an injection of prostaglandin at the time of PRID removal. Treatment with oestrogen resulted in an 18\% improvement in synchrony and a 9\% increase in conception rate. A dose level of oestrogen 4 times that given by intramuscular injection was required to achieve similar results when it was administered via a gelatine capsule attached to the PRID.}, issn = {1176-5283}, author = {Smeaton DC and Wadams TK and Hockey H-UP} } @conference {39804, title = {Influence of feeding post-lambing on ewe and lamb performance at grazing}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {179-182}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied}, issn = {1176-5283}, author = {Rattray PV and Jagusch KT and Duganzich DM and MacLean KS and Lynch RJ} } @conference {39798, title = {Influence of herbage allowance on diet quality in lactation ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {161-164}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Urinary magnesium concentrations in dairy cows follow a distinct seasonal pattern, being high during the summer and lowest during August and September, coinciding with the period when the incidence of hypomagnesaemia is at its greatest. During this critical period mean urinary Mg concentrations (Y, mg/mg creatinine) measured weekly were related to mean plasma Mg concentrations (X, mM) by expression in Y= - 7.5 + 6.2X (R}, issn = {1176-5283}, author = {Geenty KG and Sykes AR} } @conference {39755, title = {Level of nutrition of the ewe and lamb survival}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {13-14}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied}, issn = {1176-5283}, author = {Johnson DL and Clarke JN and MacLean KS and Cox EH and Amyes NC and Rattray PV} } @conference {39793, title = {Modification of antler growth in red deer stags by use of synthetic progestogen}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {145-148}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied}, issn = {1176-5283}, author = {Muir PD and Barrell GK and Sykes AR} } @conference {39753, title = {New Zealand crossbred wool: aspects of its production uses and prospects}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {1-6}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No Abstract Supplied}, issn = {1176-5283}, author = {Wickham GA} } @conference {39782, title = {New Zealand export carcass grades of lamb, mutton and beef: past, present and probable}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {107-112}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The carcass weight, composition and meat quality of entire rams, Kelly and Russian castrates, wethers and ewes under 6 months old were compared. Wether lamb carcasses averaged 0.6 kg heavier than those of the ewes and the Russian (0.4 kg), Kely (0.6 kg) and ram (0.8 kg) carcasses were heavier than those of the wethers slaughtered at the same mean age. The ram and partial castrates were less fat than the wethers (2.4 to 3.3\%) which in turn were 2.7\% less fat than the ewes. There were no practical differences in percentage carcass cuts between the rams, partial castrates or castrates. A consumer taste panel in which 48 participating families cooked and tasted a ram and wether leg roast detected no difference between the two types of meat.}, issn = {1176-5283}, author = {Barton RA} } @conference {39776, title = {Oestrogen and the PRID}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {87-90}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Ram sperm inactivated by centrifuging through a Ficoll solution were stored for 3 days at room temperature. A high proportion (80\%) of the perm was motile after reactivation with a milk diluent but compared to fresh diluted semen, the sperm gave a low pregnancy rate (6\% v 60\%).}, issn = {1176-5283}, author = {Smith JF and McGowan LT} } @conference {39760, title = {Ovulation and oestrous responses of high and low fecundity ewes to ingestion of isoflavone-rich pasture}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {29-32}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Well or poorly reared ewes were differentially fed at 1 of 5 pasture allowances for 6 weeks prior to a synchronised mating. Rearing class and flushing treatment significantly affected ovulation rate. The well and poorly reared ewes had mean multiple ovulation rates per ewe cycling of 39 and 19\% respectively. Fitting pre-flushing and joining weights as covariates removed rearing and differential feeding effects on those rates. Extrapolation of the data suggests that poorly-reared ewes would ovulate similarly to well reared ewes at similar mating weights. Facial eczema depressed live-weight gain and had a further detrimental effect on the probability of ewes ovulating.}, issn = {1176-5283}, author = {Kelly RW and Shackell GH} } @conference {39759, title = {Ovulation rates in Marshall Romney and Romney ewes: effects of body size and condition score}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {25-28}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Three lines differing markedly in reproductive performance as a result of long-term selection for litter size were compared for ovulation rates and uterine efficiency. Genetic differences in litter size were found to be due to genetic changes in ovulation rate with no evidence of altered uterine efficiency. Three additional lines also showed variation in litter size to be due to variation in ovulation rate rather than differences in uterine efficiency.}, issn = {1176-5283}, author = {Knight TW and Hockey H-UP} } @conference {39769, title = {Prevention of bark chewing of pine trees by cattle: the effectiveness of repellents}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {61-64}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Behaviour patterns which were relevant to parturition and formation of the cow-calf bond were studied and where possible related to calf survival. The relationship of maternal experience (i.e. primigravid v multigravid) to these behaviours was also studied. It was possible to predict the order in which the cows calved and the time of calving. Social isolation, localisation and ingestion of the placenta and associated fluids were found to influence calf survival. Maternal experience was directly related to the occurrence of these behaviours.}, issn = {1176-5283}, author = {Marnane NJ and Matthews LR and Kilgour R and Hawke M} } @conference {39765, title = {The productive performance of Waihora Romney cross hogget and two-tooth ewes and commercial Romneys}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {47-50}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The basic aim of selection in flocks in the 150 to 200\% lamb drop range remains unchanged, namely to breed sheep of sound physical type and with the genetic potential to give maximum net profits per hectare from sales of meat and wool. However at these fertility levels the main thrust of selection moves off fertility due to the doubtful benefit of large numbers of triplets under commercial farm conditions. More emphasis can profitably be placed on milking ability as expressed by weaning weight. This has major implications in ensuring quick seasonal disposal of lambs to reduce the pressure on stocking rate brought about by high fertility. Also fleece weight gains in importance as increases in wool production do not involve increased stocking rate. In high fertility flocks health and behaviour traits such as free lambing, mothering ability and resistance to foot problems are of even greater importance. Overall, a very important factor to be considered in future selection in high fertility flocks is that per head gains in production be made while holding ewe body weights, i.e. an emphasis on efficiency for best per hectare results.}, issn = {1176-5283}, author = {Johnston MT and Kelly RW and Webb RR} } @conference {39766, title = {Productivity of Booroola-Merino cross ewes grazing improved tussock grassland}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {51-54}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Permanent incisor eruption patterns varied widely for 13 genotypes of ewes examined. Progeny of Ruakura High Fertility Romney sires displayed markedly earlier teeth eruption than other strains while Southdowns were later than any other genotype in the study. The wide variation observed both between and within breed types questions the reliability of dentition for ageing individual animals for sale.}, issn = {1176-5283}, author = {Bray AR and Allison AJ} } @conference {39794, title = {The profitability of farming red deer in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {149-152}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Four scrub-pasture associations containing different proportions of grass, white clover and gorse were developed by grazing with different ratios of goats and sheep. The ratios were: 100\% goats (Goat 100), 66\% goats and 34\% sheep (Goat 66), 33\% goats and 67\% sheep (Goat 33) and 100\% sheep (Sheep 100). These associations were then grazed by oesophageally fistulated goats and sheep in each season for 2 years. Grass was the principal feed of sheep in all associations (77\% of diet) and of goats (62\%). Sheep ate white clover in proportion to its presence in the sward (14\%) whereas it was rejected by goats (2\%). Gorse was a preferred feed for goats (20\%) but the principal feed only when gorse >10\% of the association; sheep ate very little gorse (0.1\%). Dietary overlap between goats and sheep was greatest on the Goat 66 association (0.89), which was grass dominant. It was less on the ?Goat 100 (0.69) where sheep ate more legume, and the Goat 33 (0.66) where goats ate more gorse. On the Sheep 100 association it was the lowest (0.12) because goats ate mainly gorse and sheep mainly grass and white clover.}, issn = {1176-5283}, author = {Floyd PG} } @conference {39791, title = {Progeny test of selected lean and fat rams}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {137-140}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Separate trials were conducted to investigate the effects of a synthetic progestagen - medroxyprogesterone acetate (MPA) - on red deer stags at 2 different stages of the antler growth cycle. MPA treatment of 2 stags from the time of harvest of {\textquoteright}A-grade{\textquoteright} velvet stimulated the growth of additional sets of antlers in each case. This treatment also reduced blood testosterone levels and prevented the seasonal increase in testicular size. Alternatively, MPA treatment applied to 6 stages during their hard antler phase (winter) caused premature casting of the antler buttons in all animals. These findings indicate a possible role of MPA or similar compounds for the artificial manipulation of antler growth under farming conditions.}, issn = {1176-5283}, author = {Fennessy PF and Greer GJ and Bass JJ} } @conference {39781, title = {Recent and potential changes in meat processing and their implications for producers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {103-106}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The paper takes the view that meat sales are likely to benefit from a reduction in average fat levels, particularly in lamb. Total fat content is controlled by the mature size of the breed or strain and by the stage of maturity that has been reached. The balance between appetite (energy in) and maintenance requirement (energy lost) seems less important, although there are examples of lean genotypes with low appetites. The partitioning of total fat between carcass (particularly subcutaneous) and abdominal (particularly perirenal) sites is not influenced by mature size but rather by breed itself, especially in cattle. The reason may lie in intrinsic metabolic differences between subcutaneous and abdominal fat tissues. The number of fat cells in subcutaneous fat, but perhaps not in other fat deposits, increases as total fatness increases. Attempts to reduce eventual fat content by reducing the number of cells through underfeeding in early life have not been successful. Hormonal metabolism can be altered by injecting or implanting active constituents and sex hormone implants are presently available in some countries which aim to confer on females or castrated males the advantages (in terms of low fat and high lean deposition) of the entire male. However their effectiveness in reducing fat content is less than in increasing overall growth. Immunological techniques of growth control are being developed which leave no residues in meat and it is likely that the future will see increasing use of these and other approaches as farmers strive to meet consumers{\textquoteright} requirements for lean meat at even lower production costs.}, issn = {1176-5283}, author = {Chrystall BB} } @conference {39787, title = {Relationships of carcass conformation of cattle and sheep with carcass composition}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {125-126}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Hemicastrates and steers were slaughtered at similar carcass weights at 14, 18 and 22 months of age for the assessment of factors associated with tenderness difference in representative forequarter muscles. Objective tests indicated that hemicastrate meat was tougher than that from steers at 22 months of age only. Heat labile collagen content was the major parameter associated with tenderness in M. longissimus; in both M. splenus and M. triceps brachii it was sarcomere length.}, issn = {1176-5283}, author = {Bass JJ and Johnson DL and Woods EG and Moore RW} } @conference {39775, title = {Reproductive performance of beef cows following temporary removal of calves}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {83-86}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Bovine sperm was inactivated by centrifuging twice through a 7\% Ficoll solution. The inactivated sperm could be reactivated for periods up to 10 days with B.S.A., egg yolk, seminal plasma and milk. To test the effect of inactivation on fertility semen was either (1) immediately diluted in Caprogen + 5\% egg yolk; or (2) twice centrifuged and then diluted as above; or (3) twice centrifuged, stored in an inactivated condition for 60 h and then diluted as above. Cows were inseminated 72 h after collection of semen. Fertility following insemination was (1) 74.3\%; (2) 72.5\%; (3) 54.2\%. Storage of sperm in the inactivated condition reduced fertility (P<0.01).}, issn = {1176-5283}, author = {Tervit HR and Smith JF and Goold PG and Jones KR and Vandien JJD} } @conference {39767, title = {Selection priorities in high-fertility sheep flocks}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {55-58}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Reducing "idling" time of cattle, redirecting responses away from bark chewing, or applying a "repellent" substance could be potential management tools for controlling damage to pine trees. Egg- powder, copper carbonate, thiram, cattle dung and scatole were compared as repellents. The dung treatment was the most effective in preventing bark chewing. Egg-treated trees were licked and not chewed. As a readily available material, cattle dung has a potential use in the control of bark chewing.}, issn = {1176-5283}, author = {Black PD} } @conference {39764, title = {Shearing and time of joining effects on reproduction in two- tooth ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {45-46}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Local Merino, 1/4 local Merino and 1/2 local Merino ewes were grazed on oversown and top-dressed tussock grassland. When ranked for lamb and wool productivity at 2 and 3 years of age both the Booroola crosses were superior to the Merino. Satisfactory lamb weights and ewe fleece weights were obtained at lambing percentages above those normally obtained on this class of land.}, issn = {1176-5283}, author = {McMillan WH and Knight TW} } @conference {39773, title = {Sheep distribution and herbage utilisation after oversowing and top-dressing part of a high country summer range}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {77-78}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Calves were removed for 48 hours from cows at 2 localities in 1978. Removal shortened the interval from calving to first oestrus at both localities. It shortened the interval from calving to conception and advanced the 1979 calving date at the locality which had the better level of nutrition. Weaning weights of the removed calves were depressed at both localities. The intervals from calving to first oestrus were affected at both localities by dam age and breed, 1978 calving date and condition score at removal.}, issn = {1176-5283}, author = {Abrahamson M and O{\textquoteright}Connor KF and Harris PS} } @conference {39754, title = {The shelter requirements of the new-born lamb}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {7-12}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No Abstract Supplied}, issn = {1176-5283}, author = {Sykes AR} } @conference {39768, title = {Tooth eruption patterns in New Zealand sheep breeds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {59-60}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Daytime grazing activity of 16 high (BI = 123) and 16 low breeding index (BI = 105) cows was observed during 3, 7-day periods in early, mid and late lactation. There were no differences in grazing, lying or standing times between high and low BI cows during early or mid lactation. High BI cows grazed longer during late lactation. There were no differences in daytime drinking frequency. Individual cow milking times were recorded during 5, 2-day (4 milkings) periods at bimonthly intervals. High BI cows consistently outproduced low BI cows throughout lactation by 3 kg of milk/d. High BI cows had shorter milking times in early lactation but these differences diminished as lactation progressed. No relationships between milking entrance order or milking temperament and breeding index were found.}, issn = {1176-5283}, author = {Aitken WM and Meyer HH} } @conference {39780, title = {Trends in meat market requirements: implications for producers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {99-102}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Some information of the first exports of frozen meat from New Zealand is given partly as a background to the development of export carcass grade standards. Investigations that have examined the physical and/or chemical composition of carcasses according to grade are reviewed as are examples of research studies that have used carcass grade as one of the traits considered. On the basis of very limited evidence, it is concluded that selection of meat animals for carcass grade is unwarranted but that improvement in carcass quality through breeding should take into account the need to reduce fat content and increase the depth of muscling both of which are, or should be, closely related to carcass grade. It is emphasised that those who produce meat animals of high carcass merit should be properly rewarded for their effort. A brief speculation into the future of carcass grades is made, but whether grading will be replaced by a carcass classification scheme or some other procedure that is automatic, quick and pertinent remains in the future.}, issn = {1176-5283}, author = {Frazer AE} } @conference {39800, title = {Urinary magnesium - an indicator of magnesium status/intake?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {42}, year = {1982}, month = {Jan}, pages = {167-168}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Animal production was measured in a grazing experiment on North Island hill country from 1975 to 1981. Two grazing managements, set stocked and rotationally grazed sheep, were compared at {\textquoteright}maintenance{\textquoteright} fertiliser (LF) and {\textquoteright}high{\textquoteright} fertiliser (HF). Stocking rate increased from 6.3 to 11.3 ewes/ha and 7.3 to 15.1 ewes/ha on LF and HF respectively with no decline in per animal production. HF gave 30\% more wool/ha and 36\% more weaned lamb weight/ha as a results of the increased stocking rate. There were no fertiliser x management interactions. Management effects were inconclusive. At lower stocking rates set stocking increased ewe mating live weight, increased lambing percentage, increased lamb weaning live weight and hence increased weaned lamb weight/ha. However, at the highest stocking rate rotationally grazed ewes lost less live weight in late pregnancy and had higher lamb weight/ha.}, issn = {1176-5283}, author = {Towers NR} } @conference {39703, title = {Agricultural growth - A possibility or a fantasy?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {1-15}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Rattray PV} } @conference {39708, title = {Aspects of energy metabolism of Jersey cows differing in breeding index}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {44-47}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Trigg TE and Parr CW} } @conference {39747, title = {Breeding for facial eczema resistance - A progress report}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {273-278}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Campbell AG and Meyer HH and Henderson HV and Wesselink C} } @conference {39713, title = {The case of induced early parturition in New Zealand dairy cattle - Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {71-75}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Moller K and MacDiarmid SC} } @conference {39716, title = {A comparison of lucerne and grass-clover pastures for dairying in South Taranaki - Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {88-89}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Thomson NA and Lagan JF} } @conference {39736, title = {Early predictors of ewe fertility}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {204-208}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Meyer HH} } @conference {39715, title = {The effect of a low rate of lime on North Island hill country pasture and animal production and the economics of use}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {82-87}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {O{\textquoteright}Connor MB and Foskett HR and Smith A} } @conference {39748, title = {The effect of daily infection with O. circumcincta larvae on the performance of pregnant and lactating sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {279-282}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Leyva V and Henderson AE and Sykes AR} } @conference {39724, title = {Effect of grazing management on hogget fleece characteristics}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {128-132}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Sumner RMW and During C and Webby RW} } @conference {39752, title = {The effect of growth implants on cattle and sheep production - Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {294-296}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McKenzie JR} } @conference {39735, title = {Effect of mating Romney ewe hoggets on lifetime production - Preliminary results}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {198-203}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Baker RL and Clarke JN and Diprose GD} } @conference {39706, title = {Effect of nutrition and mating management on calving patterns}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {34-38}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McGowan AA} } @conference {39721, title = {The effect of season of the year and pasture allowance on the growth of lambs fed different pasture species - Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {117-118}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Jagusch KT and Duganzich DM and Winn GW and Rattray PV} } @conference {39718, title = {The effect of sheep and cattle grazing on a mixed ryegrass/kikuyu/white clover pasture in Northland}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {95-100}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Goold GJ} } @conference {39731, title = {Effects of genotype, liveweight, pasture type and feeding level on ovulation responses in ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {174-182}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Rattray PV and Jagusch KT and Smith JF and Winn GW and MacLean KS} } @conference {39704, title = {The efficiency with which feed is utilised by the dairy cow}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {16-27}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Holmes CW and Davey AWF and Grainger C} } @conference {39730, title = {Energy requirements of red deer}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {167-173}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Fennessy PF and Moore GH and Corson ID} } @conference {39723, title = {Factors relating to lamb production efficiency on Southland farms - Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {125-127}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Harbord MW} } @conference {39739, title = {Fertilisation rate of ewes mated to high and low prolificacy Romney rams}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {224-228}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Moore RW} } @conference {39728, title = {The heat of warming feed}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {152-162}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Nicol AM and Young BA} } @conference {39727, title = {Herbage quality and physical breakdown in the foregut of sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {142-151}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Moseley G} } @conference {39712, title = {The hormonal induction of lactation in dry dairy cows - Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {68-70}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Davis SR and Welch RAS and Pearce MG and Peterson AJ} } @conference {39711, title = {Hypomagnesaemia and dairy production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {61-67}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Young PW and Rys G and O{\textquoteright}Connor MB} } @conference {39734, title = {Increasing the ovulation rate in ewes by immunisation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {193-197}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Smith JF and Cox RI and McGowan LT and Wilson PA and Hoskinson RM} } @conference {39742, title = {Intake and growth performance of grazing lambs weaned at 4 and 12 weeks of age}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {235-241}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Geenty KG and Sykes AR} } @conference {39738, title = {Interrelationships of placental development with nutrition in pregnancy and lamb birth weight}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {218-223}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Davis SR and Rattray PV and Petch ME and Duganzich DM} } @conference {39710, title = {The magnesium status of grazing dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {53-60}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Wilson GF} } @conference {39740, title = {Marked udder method (MUM) - A technique for identifying the progeny of ewes where identification at birth is not practicable}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {229-232}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Davis GH and Wallis TR and Bray AR} } @conference {39729, title = {Metabolisable energy required by feral goats for maintenance and the effects of cold climatic conditions on their heat production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {163-166}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Holmes CW and Moore YF} } @conference {39705, title = {A model for analysing alternative feeding strategies during the lactation cycle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {28-33}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Townsley RJ and Grainger C and McGowan AA} } @conference {39717, title = {Modelling a hill-country sheep production system}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {90-94}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Field TRO and Clark DA and Lambert MG} } @conference {39726, title = {The nutrients available to grazing cattle - Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {140-141}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Ulyatt MJ and Beever DE and Thomson DJ} } @conference {39746, title = {Nutrition of weaner beef heifers; growth, puberty and yearling mating on hill country}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {267-272}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Smeaton DC and Winn GW} } @conference {39744, title = {Nutritional {\textquoteright}tapering{\textquoteright} of farm livestock}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {248-253}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Jagusch KT and Smith JF and Rattray PV} } @conference {39733, title = {Oestrus and ovarian activity of Booroola merino crossbred ewe hoggets - Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {189-192}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Cleverdon JM and Hart DS} } @conference {39743, title = {Paired comparison analysis of palatabilities of twenty foods to dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {242-247}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Klopfer FD and Kilgour R and Matthews LR} } @conference {39719, title = {Pasture production and sward dynamics under sheep grazing}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {101-111}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Baars JA and Jagusch KT and Dyson CB and Farquhar PA} } @conference {39745, title = {Performance of crossbred cows in the Ruakura beef breed evaluation trial}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {254-266}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Baker RL and Carter AH and Muller JP} } @conference {39722, title = {Phalaris and ryegrass pastures for animal production in Hawkes Bay}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {119-124}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Wright DF and Kain WM and Hamilton GJ and Slay MWA and Luckman MS} } @conference {39714, title = {Physical effects within the teatcup related to intra-mammary infection}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {76-81}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Woolford MW and Williamson JH and Phillips DSM} } @conference {39732, title = {Problems in flushing ewes on North Island hill country}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {183-188}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Smeaton DC and Knight TW and Winn GW} } @conference {39709, title = {Production differences between Jersey and Friesian x Jersey cows in commercial dairy herds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {48-52}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Macmillan KL and Duganzich DM and Bryant AM} } @conference {39707, title = {Progress report on the performance of Jersey cows differing in breeding index}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {39-43}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Bryant AM and Trigg TE} } @conference {39741, title = {Protein deficiency in growing lambs fed fresh ryegrass/clover pasture ad libitum}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {233-234}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Barry TN and Manley TR and Redekopp C} } @conference {39725, title = {The repeatability of ultrasonic fat-depth measurements made on sheep up to 18 months of age}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {133-139}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Purchas RW and Rae AL and Barton RA and Beach AD} } @conference {39751, title = {Selenium, cobalt and copper supplementation of beef cattle in Northern Southland}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {293}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Reid TC} } @conference {39737, title = {The starvation-exposure syndrome and neonatal lamb mortality: A review}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {209-217}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McCutcheon SN and Holmes CW and McDonald MF} } @conference {39750, title = {Successful semi-commercial artificial insemination of ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {288-292}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Meyer HH and Harvey TG} } @conference {39720, title = {Summer ill-thrift in lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {112-116}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Scales GH and Moss RA and Burton RN} } @conference {39749, title = {Wool growth of ewes during autumn on hill country}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {283-287}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Sumner RMW and Smeaton DC} } @conference {39673, title = {Biochemical aspects of ram sperm viability}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {130-135}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {van Eerten MTW and Forrester IT} } @conference {39684, title = {Bulk: A wool trait of importance to the carpet industry}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {196-204}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Carnaby GA and Elliott KH} } @conference {39683, title = {Cell Biology and wool production and properties}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {189-195}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Orwin DFG} } @conference {39677, title = {Comparative digestive physiology and metabolism of the red deer and the sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {151-157}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Milne JA} } @conference {39653, title = {The control of internal parasites in lambs by grazing management}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {18-22}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Lewis KHC and Mason PC} } @conference {39665, title = {Correlating stock and pasture production in Northland}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {85-91}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Rumball PJ} } @conference {39661, title = {Effect of herbage allowance on dairy cow performance}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {50-58}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Bryant AM} } @conference {39662, title = {The effect of herbage allowance on the dry matter intake and milk production of dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {59-63}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Glassey CB and Davey AWF and Holmes CW} } @conference {39688, title = {Effect of increasing phosphorus intake on the P faecal endogenous loss in the sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {221-225}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Grace ND} } @conference {39690, title = {The effect of level of feeding of pasture on its digestion by lactating dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {227-230}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Trigg TE and Bryant AM and Cox NR} } @conference {39660, title = {The effect of lucerne feeding on ovulation rate in ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {44-49}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Smith JF and Jagusch KT and Brunswick LFC and McGowan LT} } @conference {39659, title = {Effect of nutrition on ovulation rate and litter size in Booroola-Merino cross and Merino ewes - Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {43}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Bray AR and Montgomery GW and Wallis TR} } @conference {39658, title = {Effects of diet and liveweight on ovulation rates in {\textquoteright}Romney{\textquoteright} ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {38-42}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Knight TW} } @conference {39656, title = {Effects of different growth paths from 4 to 11 months of age on Romney hogget oestrus and subsequent reproduction}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {27-33}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Moore RW and Smeaton DC} } @conference {39652, title = {Effects of level of nutrition and drenching strategy on pasture utilization during autumn by set-stocked hoggets infected with gastro-intestinal nematodes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {12-17}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Jagusch KT and Rattray PV and Petch M and Vlassoff A} } @conference {39686, title = {Effects of short-term differential feeding in the autumn on liveweight gains and wool growth of ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {209-214}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Sumner RMW and Rattray PV} } @conference {39668, title = {Effects of soil-contaminated feed on dry matter and water intake in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {106-110}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Pownall DB and Lucas RJ and Ross AD} } @conference {39689, title = {Factors influencing nitrogen flow from the rumen}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {226}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {John A and Ulyatt MJ and Jones WT and Shelton ID} } @conference {39693, title = {Factors influencing the interval to post-partum oestrus, conception date and empty rate in an intensively managed dairy herd}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {236-239}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Macmillan KL and Clayton DG} } @conference {39657, title = {Flushing responses from heavy and light ewes - Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {34-37}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Rattray PV and Jagusch KT and Smith JF and Winn GW and MacLean KS} } @conference {39674, title = {Grazing ruminants: Evaluation of their feeds and needs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {136-144}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Corbett JL} } @conference {39680, title = {The implications of milking management strategies involving variations of milking frequency in the immediate post-partum period}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {166-174}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Phillips DSM and Woolford MW and Copeman PJA} } @conference {39654, title = {The influence of internal parasites on replacement dairy heifers during their second year of life - Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {23-24}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Day AM} } @conference {39698, title = {Intensive wintering of beef steers in Northland}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {268-271}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Shannon PW and During C} } @conference {39700, title = {Interval from calving to first oestrus in autumn- and spring- calving herds in the same locality}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {280-284}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Montgomery GW and Davis GH and Hurrell GA} } @conference {39672, title = {Laser light scattering as a probe of sperm motility}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {124-129}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Woolford MW and Woolhouse JK and Phillips DSM and Hawley SA and Harvey JD and Shannon P and Curson B} } @conference {39696, title = {Liveweight variation in Sheeplan flocks}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {254-257}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Johnson DL and Clarke JN and Robinson CA} } @conference {39651, title = {Lost potential - a matter of national concern}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {1-11}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Macmillan KL} } @conference {39681, title = {Milk production losses associated with clinical mastitis within identical-twin sets}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {175-179}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Woolford MW and Williamson JH} } @conference {39663, title = {Modelling the contribution of forage crops to production, profitability and stability of North Island dairy systems}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {64-67}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Miller CP} } @conference {39691, title = {Nutritional evaluation of kale (Brassica oleracea)}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {231-234}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Barry TN and Manley TR and Reid TC and Wilson KR and Hemmingsen P and Millar KR} } @conference {39675, title = {Passage of Cr-EDTA through the digestive tract of cattle and sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {145-149}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Poppi DP and Minson DJ} } @conference {39666, title = {Pasture allowance and lamb growth}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {92-97}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Thompson KF and McEwan JC and Risk WH} } @conference {39694, title = {A plan for improving the fecundity of a flock by indirect selection}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {240-247}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Hull FTL and Hanning RKT} } @conference {39702, title = {Preliminary results of selection for yearling or 18-month weight in Angus and Hereford cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {304-311}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Baker RL and Carter AH and Hunter JC} } @conference {39670, title = {Production potential of extension is not fully exploited}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {117}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McKenzie SA} } @conference {39679, title = {The relationship between the degree of udder development and milk production in Coopworth ewes - Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {163-165}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Davis SR and Hughson G and Farquhar PA and Rattray PV} } @conference {39667, title = {The relationship of pasture parameters to liveweight gain of hoggets on North Island hill country}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {98-105}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {During C and Dyson CB and Webby RW} } @conference {39682, title = {Relationships between milk somatic cell counts, production index and dry cow therapy in seasonal dairy herds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {180-188}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Macmillan KL and Duirs GF and Hook IS} } @conference {39697, title = {The relationships of growth, body shape, and body composition to the initiation of oestrous activity in different sheep breeds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {258-267}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Stephenson SK and Dalton DC and Kirton AH} } @conference {39695, title = {Repeatability of reproduction rate components in Merino and Booroola x Merino ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {248-253}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Lewer RP and Allison AJ} } @conference {39692, title = {Reproductive efficiency in twenty town supply dairy herds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {235}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Fielden ED and Harris RE and Macmillan KL and Shrestha SL} } @conference {39687, title = {A review of effects of shearing on sheep production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {215-220}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Smith ME and Bigham ML and Knight TW and Sumner RMW} } @conference {39701, title = {The role of maternal effects on the efficiency of selection in beef cattle - A review}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {285-303}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Baker RL} } @conference {39655, title = {Sheep thrift problems under irrigation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {25-26}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Oliver JR and Gumbrell RC and McKnight LJ} } @conference {39671, title = {Some factors which influenced knowledge and use of tail painting - A study of extension}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {118-123}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Macmillan KL} } @conference {39664, title = {Some implications of sward chemical and physical characteristics for the nutrition of grazing ruminants}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {68-84}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Hughes TP and Poppi D and Sykes AR} } @conference {39676, title = {Stomach fermentation and digesta flow in macropodine marsupials and sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {150}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Dellow DW and Hume ID} } @conference {39699, title = {The successful development of a PRID regime for oestrous synchronization in New Zealand beef cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {272-279}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Smith JF and Tervit HR} } @conference {39669, title = {Training sheep as {\textquoteright}leaders{\textquoteright} in abattoirs and farm sheep yards}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {111-116}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Bremner KJ and Braggins JB and Kilgour R} } @conference {39678, title = {Voluntary intake and digestion in red deer and sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {158-162}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Fennessy PF and Greer GJ and Forss DA} } @conference {39685, title = {Wool production and characteristics of Merino and Longwool ewes and their respective Booroola crosses}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {40}, year = {1980}, month = {Jan}, pages = {205-208}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Hawker H and Davis GH and Allison AJ} } @conference {39620, title = {Age and breed effect of ram on ewe{\textquoteright}s reproductive performance}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {39}, year = {1979}, month = {Jan}, pages = {77-86}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Ch{\textquoteright}ang TS and Evans R} } @conference {39641, title = {Beef breed evaluation - breed utilization strategies}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {39}, year = {1979}, month = {Jan}, pages = {223}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Johnson DL and Morris CA} } @conference {39643, title = {The biochemical assessment of energy status in the grazing lactating ruminant}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {39}, year = {1979}, month = {Jan}, pages = {233-241}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Payne E and Trigg TE and Rattray PV and Nicoll GB and Smeaton DC} } @conference {39634, title = {Calving patterns and herd production in seasonal dairy herds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {39}, year = {1979}, month = {Jan}, pages = {168-174}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Macmillan KL} } @conference {39639, title = {A comparison of the fatness of weaned and unweaned lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {39}, year = {1979}, month = {Jan}, pages = {211-216}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Purchas RW} } @conference {39647, title = {Effect of herbage allowance on intake and utilization of pasture by cattle of different ages}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {39}, year = {1979}, month = {Jan}, pages = {260-264}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Trigg TE and Marsh R} } @conference {39646, title = {The effect of herbage yield and allowance on growth and carcass characteristics of weaned lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {39}, year = {1979}, month = {Jan}, pages = {254-259}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Jagusch KT and Rattray PV and Oliver TW and Cox NR} } @conference {39627, title = {The effect of selection for body weight at different ages on fat deposition in mice}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {39}, year = {1979}, month = {Jan}, pages = {118-128}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Baker RL and Carter AH and Cox EH} } @conference {39623, title = {The effect of shearing ewes during the mating period on the subsequent lambing pattern}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {39}, year = {1979}, month = {Jan}, pages = {100-102}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Welch RAS and Kilgour R and Robson GA and Smith ME and Williams ET} } @conference {39624, title = {The effect of time of shearing on plasma gamma glutamyltransferase levels after a facial eczema outbreak}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {39}, year = {1979}, month = {Jan}, pages = {103-105}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Smith ME and Towers NR and Giles KH} } @conference {39615, title = {Effects of differential nutrition on the incidence of oestrus and ovulation rate in Booroola x Romney and Romney ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {39}, year = {1979}, month = {Jan}, pages = {43-49}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Allison AJ and Kelly RW} } @conference {39638, title = {Effects of weaning age on export lamb production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {39}, year = {1979}, month = {Jan}, pages = {202-210}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Geenty KG} } @conference {39625, title = {The effects of winter grazing systems on some wool characteristics}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {39}, year = {1979}, month = {Jan}, pages = {106-114}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Horton CT and Wickham GA} } @conference {39619, title = {Ewe and teaser breed effects on reproductive behaviour and performance}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {39}, year = {1979}, month = {Jan}, pages = {68-76}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Meyer HH} } @conference {39632, title = {An examination of managerial practices on a high producing dairy farm in relation to experimental results}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {39}, year = {1979}, month = {Jan}, pages = {154-163}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Davis BN and Bartlett KR and Scott JDJ and Bryant AM and Cook MAS} } @conference {39628, title = {Factors influencing conception rates to artificial breeding in New Zealand dairy herds: A review}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {39}, year = {1979}, month = {Jan}, pages = {129-137}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Macmillan KL} } @conference {39645, title = {Farm production gains following adoption of a hill country grazing management system}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {39}, year = {1979}, month = {Jan}, pages = {251-253}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Smith ME and McLaren PN and Hopkins DR} } @conference {39648, title = {Feed intake of grazing Friesian bulls}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {39}, year = {1979}, month = {Jan}, pages = {265-274}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Clark DA and Brougham RW} } @conference {39636, title = {Genetic parameters and economic values of traits other than production for dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {39}, year = {1979}, month = {Jan}, pages = {180-193}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Wickham BW} } @conference {39612, title = {Hill country: a major agricultural resource and its capacity for increased production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {39}, year = {1979}, month = {Jan}, pages = {1-12}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Hight GK} } @conference {39617, title = {Hogget liveweight-oestrus relationship among sheep breeds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {39}, year = {1979}, month = {Jan}, pages = {56-62}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Meyer HH and French RL} } @conference {39630, title = {Immediate and longer term response of dairy cows to level of nutrition in early lactation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {39}, year = {1979}, month = {Jan}, pages = {139-147}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Bryant AM and Trigg TE} } @conference {39621, title = {The influence of sires on lamb survival}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {39}, year = {1979}, month = {Jan}, pages = {87-93}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Knight TW and Hight GK and Winn GW} } @conference {39637, title = {Interrelationships between GR and other lamb carcass fatness measurement}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {39}, year = {1979}, month = {Jan}, pages = {194-201}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Kirton AH and Johnson DL} } @conference {39635, title = {Interrelationships between somatic cell counts, production, age and mastitis organisms in individual cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {39}, year = {1979}, month = {Jan}, pages = {175-179}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Duirs GF and Macmillan KL} } @conference {39649, title = {Leaf protein concentrate quality: The effect of pasture species and reducing agent}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {39}, year = {1979}, month = {Jan}, pages = {275-280}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Donnelly PE and McDonald RM} } @conference {39622, title = {Mating management and reproductive activity of intensively farmed red deer}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {39}, year = {1979}, month = {Jan}, pages = {94-99}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Bray AR and Kelly RW} } @conference {39613, title = {McMeekan Memorial Lecture: The contribution of research to grasslands farming in Western Europe}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {39}, year = {1979}, month = {Jan}, pages = {13-22}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {O{\textquoteright}Keefe P} } @conference {39631, title = {Milkfat production increases due to an advisory programme aimed at increasing the feed supply on dairy farms}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {39}, year = {1979}, month = {Jan}, pages = {148-153}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Mace MJ and Peterson DCV} } @conference {39644, title = {Minimal feeding of pregnant ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {39}, year = {1979}, month = {Jan}, pages = {242-250}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Rattray PV and Trigg TE} } @conference {39616, title = {Ovulation-liveweight relationships in ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {39}, year = {1979}, month = {Jan}, pages = {50-55}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Smith JF and Rattray PV and Jagusch KT and Cox NR and Tervit HR} } @conference {39629, title = {The relation of pasture allowance to changes in body condition and weight of pregnant non-lactating cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {39}, year = {1979}, month = {Jan}, pages = {138}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Holmes CW and McLenaghan RJ and Auko P and Nottingham R} } @conference {39640, title = {Relationships between ultrasonic measurements taken on live cattle and their carcass composition}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {39}, year = {1979}, month = {Jan}, pages = {217-222}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Bass JJ} } @conference {39618, title = {Reproductive rate and wool production of two strains of Australian Merino and their crosses with the Booroola Merino}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {39}, year = {1979}, month = {Jan}, pages = {63-67}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Piper LR and Bindon BM and Killeen ID and McGuirk BJ} } @conference {39614, title = {A review of the influence of liveweight and flushing on fertility made in the context of efficient sheep production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {39}, year = {1979}, month = {Jan}, pages = {23-42}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Cockrem FRM} } @conference {39642, title = {Selection for increased cow fecundity: A review}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {39}, year = {1979}, month = {Jan}, pages = {224-232}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Piper LR and Bindon BM} } @conference {39650, title = {A statistical appraisal of sacred cow - Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {39}, year = {1979}, month = {Jan}, pages = {281-283}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Johnstone PD} } @conference {39633, title = {The value of MAF advisory services in a dairy discussion group}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {39}, year = {1979}, month = {Jan}, pages = {164-167}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Dawson AD and Smith ME} } @conference {39626, title = {Wool production of exotic x Romney sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {39}, year = {1979}, month = {Jan}, pages = {115-117}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Bigham ML and Meyer HH} } @conference {39576, title = {Adopting new technologies and raising dairy production - A matter of incentives}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {38}, year = {1978}, month = {Jan}, pages = {20-29}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Hutton JB} } @conference {39602, title = {Beef production on an all-crop grazing system - Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {38}, year = {1978}, month = {Jan}, pages = {147-150}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Stephen RC and McDonald RC} } @conference {39579, title = {The characteristics of carpet wools in relation to processing and performance}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {38}, year = {1978}, month = {Jan}, pages = {34-41}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Ross DA} } @conference {39599, title = {Compensatory growth of beef cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {38}, year = {1978}, month = {Jan}, pages = {141}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Scales GH and Taylor AG} } @conference {39581, title = {Development and control of ryegrass staggers in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {38}, year = {1978}, month = {Jan}, pages = {47-52}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Keogh RG} } @conference {39597, title = {The dynamics of pasture production under sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {38}, year = {1978}, month = {Jan}, pages = {129-138}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Jagusch KT and Rattray PV and MacLean KS and Joyce JP} } @conference {39586, title = {Economic evaluations of exotic sheep crosses in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {38}, year = {1978}, month = {Jan}, pages = {71-78}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Sorrenson WJ and Scott ME} } @conference {39609, title = {Effect of date of harvest and conservation method on the feeding value of conserved pasture for beef cattle at pasture}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {38}, year = {1978}, month = {Jan}, pages = {191-195}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Marsh R and Ward JDB} } @conference {39605, title = {An effect of pasture on the secretion of salivary proteins by the cow}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {38}, year = {1978}, month = {Jan}, pages = {174}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Cockrem FRM and McIntosh JT} } @conference {39577, title = {Factors associated with high productivity on a dairy farm}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {38}, year = {1978}, month = {Jan}, pages = {30}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Crowley A and Kilgarriff PJ} } @conference {39606, title = {Factors influencing the interval from calving to first oestrus in beef cattle on North Island hill country}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {38}, year = {1978}, month = {Jan}, pages = {175-180}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Knight TW and Nicoll GB} } @conference {39578, title = {A farmer{\textquoteright}s concept of the New Zealand wool industry}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {38}, year = {1978}, month = {Jan}, pages = {31-33}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Carter DR} } @conference {39596, title = {Field estimates of daily winter feed allowance for grazing ewes in Southland - Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {38}, year = {1978}, month = {Jan}, pages = {127-128}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Thompson KF and Cooney GJ} } @conference {39591, title = {Flushing ewes on pasture and pasture silage}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {38}, year = {1978}, month = {Jan}, pages = {101-104}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Rattray PV and Jagusch KT and Smith JF and Tervit HR} } @conference {39607, title = {Genetic and environmental effects on incidence and causes of lamb mortality}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {38}, year = {1978}, month = {Jan}, pages = {181-184}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Meyer HH and Clarke JN} } @conference {39604, title = {Genetic progress from performance and progeny test selection in down sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {38}, year = {1978}, month = {Jan}, pages = {161-173}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Eikje ED} } @conference {39600, title = {The growth and carcass characteristics of entire and castrate red stags}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {38}, year = {1978}, month = {Jan}, pages = {142-144}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Drew KR and Fennessy PF and Greer GJ} } @conference {39589, title = {Influence of hogget oestrus on subsequent ewe fertility}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {38}, year = {1978}, month = {Jan}, pages = {90-96}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Moore RW and Knight TW and Whyman D} } @conference {39590, title = {Insemination of sheep with fresh or frozen semen}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {38}, year = {1978}, month = {Jan}, pages = {97-100}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Tervit HR and Smith JF and Goold PG and Drost H} } @conference {39593, title = {Management effects on productivity of southern North Island hill country}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {38}, year = {1978}, month = {Jan}, pages = {110-115}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Grant DA and Lambert MG and Guy MC} } @conference {39584, title = {Manipulation of liver metabolism in relation to ruminant toxicology}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {38}, year = {1978}, month = {Jan}, pages = {59-64}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Mortimer PH and Manns E and Coe BD} } @conference {39608, title = {Milk yield and composition from cows grazing lucerne}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {38}, year = {1978}, month = {Jan}, pages = {185-190}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Bryant AM} } @conference {39594, title = {Mixed grazing of cattle and sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {38}, year = {1978}, month = {Jan}, pages = {116-120}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Boswell CC and Cranshaw LJ} } @conference {39595, title = {Pasture allowances for the breeding ewe}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {38}, year = {1978}, month = {Jan}, pages = {121-126}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Rattray PV and Jagusch KT} } @conference {39610, title = {Possible exploitation of body composition-nutrition interrelationships for early weaning of calves}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {38}, year = {1978}, month = {Jan}, pages = {196-201}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Donnelly PE and Fennessy PF} } @conference {39611, title = {Pre-calving nutrition of beef cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {38}, year = {1978}, month = {Jan}, pages = {202-208}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Reardon TF and Welch RAS and Wright DE and Brinsmead MW} } @conference {39574, title = {Presidential Address: Research in dairy cow nutrition}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {38}, year = {1978}, month = {Jan}, pages = {1-8}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Bryant AM} } @conference {39598, title = {Re-Implanting Ralgro in fattening steers - Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {38}, year = {1978}, month = {Jan}, pages = {139-140}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McKenzie JR and South AC} } @conference {39587, title = {The risk of importing scrapie with exotic breeds of sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {38}, year = {1978}, month = {Jan}, pages = {79}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Bruere AN} } @conference {39582, title = {Ryegrass staggers: A role for fungal tremorgens}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {38}, year = {1978}, month = {Jan}, pages = {53-57}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Reid CSW and Keogh RG and Latch GCM and Gallagher RT} } @conference {39580, title = {Ryegrass staggers in sheep and cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {38}, year = {1978}, month = {Jan}, pages = {42-46}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Byford MJ} } @conference {39603, title = {Some components of improved beef cow productivity on hill country}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {38}, year = {1978}, month = {Jan}, pages = {151-160}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Nicoll GB and Hight GK and Everitt GC} } @conference {39585, title = {Studies on sporidesmin metabolism in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {38}, year = {1978}, month = {Jan}, pages = {65-70}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Fairclough RJ and Sissons CH and Holland PT and Ronaldson JW} } @conference {39592, title = {Summer supplementary feeding of ewes in Northland}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {38}, year = {1978}, month = {Jan}, pages = {105-109}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Piggot GJ and Packard PM and Renshaw JA} } @conference {39588, title = {A system of identifying factors limiting the reproductive performance of commercial sheep flocks}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {38}, year = {1978}, month = {Jan}, pages = {80-89}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Kelly RW and Allison AJ and Johnstone PD} } @conference {39601, title = {Techniques of administrating progestogens for oestrus synchronization in cattle - Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {38}, year = {1978}, month = {Jan}, pages = {145-146}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Smith JF} } @conference {39583, title = {Tremorgenic penicillia in ryegrass staggers outbreaks}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {38}, year = {1978}, month = {Jan}, pages = {58}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {di Menna ME} } @conference {39575, title = {The value of incentives and subsidies for increasing livestock production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {38}, year = {1978}, month = {Jan}, pages = {9-19}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Taylor NW} } @conference {39540, title = {Agonistic Behaviour of Grazing Heifers During Dairy Herd Formation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {37}, year = {1977}, month = {Jan}, pages = {50-51}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Dee BA} } @conference {39544, title = {Beef Production from Lucerne}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {37}, year = {1977}, month = {Jan}, pages = {67-71}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Joyce JP and Brunswick LCF} } @conference {39545, title = {Breed and Sex Effects on the Content of Edible Meat in Beef Carcasses}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {37}, year = {1977}, month = {Jan}, pages = {72-81}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Everitt GC and Jury KE and Ward JDB} } @conference {39562, title = {Breeding Objectives for New Zealand Sheep Production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {37}, year = {1977}, month = {Jan}, pages = {182}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Morris CA and Clarke JN} } @conference {39557, title = {Calorimetric facilities for dairy cattle at Ruakura Animal Research Station}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {37}, year = {1977}, month = {Jan}, pages = {158-162}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Bryant AM and Hughes JW and Hutton JB and Newth RP and Parr CR and Trigg TE and Young J} } @conference {39536, title = {Comparative Dairy Production of Jerseys and Friesian-Jersey Crossbreds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {37}, year = {1977}, month = {Jan}, pages = {25-31}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Campbell AG} } @conference {39570, title = {A comparison of sire and dam breeds for the production of export lambs slaughtered at 3, 4?, and 6 months of age}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {37}, year = {1977}, month = {Jan}, pages = {235-242}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Geenty KG and Clarke JN} } @conference {39555, title = {Depression of lambing percentage from mating on lucerne}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {37}, year = {1977}, month = {Jan}, pages = {149-151}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Coop IE} } @conference {39554, title = {Effect of breed of ram on the onset of the breeding season in Romney ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {37}, year = {1977}, month = {Jan}, pages = {142-148}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Tervit HR and Havik PG and Smith JF} } @conference {39542, title = {Effect of Herbage Per Unit Area and Herbage Allowance on Dry Matter Intake by Steers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {37}, year = {1977}, month = {Jan}, pages = {58-61}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Reardon TF} } @conference {39543, title = {The Effect of Level of Herbage Dry Matter Per Animal on Efficiency of Utilization of Pasture by Young Friesian Cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {37}, year = {1977}, month = {Jan}, pages = {62-66}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Marsh R} } @conference {39535, title = {The Effect of Level of Meal Allowance on the Growth of Early-Weaned Calves at Pasture}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {37}, year = {1977}, month = {Jan}, pages = {20-24}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Donnelly PE} } @conference {39559, title = {Energy cost of protein deposition in the pre-ruminant and young ruminant lamb}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {37}, year = {1977}, month = {Jan}, pages = {167-172}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Rattray PV and Jagusch KT} } @conference {39558, title = {The energy metabolism of young Friesian calves fed on a diet of milk and concentrate}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {37}, year = {1977}, month = {Jan}, pages = {163-166}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Hughes TP and Holmes CW and Davey AWF} } @conference {39565, title = {Group breeding schemes in sheep improvement in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {37}, year = {1977}, month = {Jan}, pages = {206-212}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Rae AL} } @conference {39571, title = {Hormonal responses of lambs to trucking, handling and electric stunning}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {37}, year = {1977}, month = {Jan}, pages = {243-248}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Pearson AJ and Kilgour R and de Langen H and Payne E} } @conference {39572, title = {Improving forage nutritive value: Some recent findings in forage conservation research in Europe}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {37}, year = {1977}, month = {Jan}, pages = {249-257}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Barry TN and Wilkinson JM and Wilkins RJ} } @conference {39541, title = {Induced Calving with Cortiscosteroids: A Comparison Between Induced Cows and Their Calves and Control Animals}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {37}, year = {1977}, month = {Jan}, pages = {52-57}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Welch RAS and Kaltenbach CC} } @conference {39549, title = {The influence of plane of nutrition immediately post-calving on the performance of beef cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {37}, year = {1977}, month = {Jan}, pages = {103-108}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Nicol AM} } @conference {39548, title = {The influence of pre- and post-calving nutrition on beef cow and calf performance}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {37}, year = {1977}, month = {Jan}, pages = {96-102}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Scales GH and Stevenson JR and Platt MP} } @conference {39566, title = {Investigations of carpet wool genes in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {37}, year = {1977}, month = {Jan}, pages = {213-217}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Wickham GA and Rae AL} } @conference {39552, title = {Observations on the behaviour and factors influencing the sexually-active group in cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {37}, year = {1977}, month = {Jan}, pages = {128-135}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Kilgour R and Skarsholt BH and Smith JF and Bremner KJ and Morrison MCL} } @conference {39551, title = {Oestrus Synchronization in Beef Cattle: A Review}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {37}, year = {1977}, month = {Jan}, pages = {120-127}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Smith JF} } @conference {39564, title = {Organization of Sheep Improvement in Norway}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {37}, year = {1977}, month = {Jan}, pages = {198-205}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Eikje ED} } @conference {39560, title = {The physical breakdown of feed during digestion in the rumen}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {37}, year = {1977}, month = {Jan}, pages = {173-175}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Reid CSW and Ulyatt MJ and Monro JA} } @conference {39537, title = {Planned Animal Health and Production Services - An Economic Evaluation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {37}, year = {1977}, month = {Jan}, pages = {32-38}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Jackman JB and Moller K} } @conference {39573, title = {The popular press as an information medium and forum in animal production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {37}, year = {1977}, month = {Jan}, pages = {258-262}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Wilson B} } @conference {39550, title = {Post-partum anoestrus in beef cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {37}, year = {1977}, month = {Jan}, pages = {109-119}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Tervit HR and Smith JF and Kaltenbach CC} } @conference {39534, title = {Presidential Address: The Sheep and Cattle Industries in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {37}, year = {1977}, month = {Jan}, pages = {1-19}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Scott JDJ} } @conference {39547, title = {The relationship between Central Test Station performance and subsequent progeny performance for growth traits of Hereford Bulls}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {37}, year = {1977}, month = {Jan}, pages = {89-95}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Wickham BW} } @conference {39553, title = {Relationship between semen traits, mating frequency and percentage of ewes lambing multiples in high fertility Romney sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {37}, year = {1977}, month = {Jan}, pages = {136-141}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Moore RW and Whyman D} } @conference {39569, title = {Reproductive Performance and Wool Production of Merino and High Fertility Strain (Booroola) x Merino Ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {37}, year = {1977}, month = {Jan}, pages = {230-234}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Allison AJ and Stevenson JR and Kelly RW} } @conference {39568, title = {Reproductive performance, growth and wool production of exotic sheep and their crosses with the Romney}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {37}, year = {1977}, month = {Jan}, pages = {220-229}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Meyer HH and Clarke JN and Bigham ML and Carter AH} } @conference {39556, title = {Reproductive performance of ewes mated on lucerne}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {37}, year = {1977}, month = {Jan}, pages = {152-157}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Scales GH and Moss RA and Kelly RW} } @conference {39538, title = {Response of Cows in Early Lactation When Offered Maize Silage to Appetite and Restricted Areas of Pasture}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {37}, year = {1977}, month = {Jan}, pages = {39-45}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Bryant AM and Cook MAS} } @conference {39539, title = {Response of Lactating Cows to Abomasal Infusions of Casein, Methionine and Glucose}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {37}, year = {1977}, month = {Jan}, pages = {46-49}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Rogers GL and McLeay LM} } @conference {39561, title = {Rumen motility in sheep and cattle as affected by feeds and feeding}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {37}, year = {1977}, month = {Jan}, pages = {176-181}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Waghorn GC and Reid CSW} } @conference {39563, title = {Technical Aspects of the National Sheep Recording Scheme (Sheeplan)}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {37}, year = {1977}, month = {Jan}, pages = {183-197}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Clarke JN and Rae AL} } @conference {39546, title = {Value of Conformation in New Zealand Beef Grading}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {37}, year = {1977}, month = {Jan}, pages = {82-88}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Bass JJ and Robinson C and Colomer-Rocher F} } @conference {39567, title = {Wool Production of Sheep Breeds on Hill Country}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {37}, year = {1977}, month = {Jan}, pages = {218-219}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Bigham ML and Elliott KH and Dalton DC} } @conference {39525, title = {An analysis of Angus central bull performance tests in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {36}, year = {1976}, month = {Jan}, pages = {210-215}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Dalton DC} } @conference {39504, title = {The Application of oestrus synchronization in New Zealand dairy herds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {36}, year = {1976}, month = {Jan}, pages = {50-57}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Macmillan KL and Curnow RJ} } @conference {39516, title = {The basis of nutritive value - a modelling approach}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {36}, year = {1976}, month = {Jan}, pages = {140-149}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Ulyatt MJ and Baldwin RL and Koong LJ} } @conference {39533, title = {Behaviour at lambing of Romney ewes with exotic breed lambs: An interim report}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {36}, year = {1976}, month = {Jan}, pages = {258-260}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Kilgour R and de Langen H and Bremner K} } @conference {39523, title = {Carcass composition of purebred and crossbred Angus steers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {36}, year = {1976}, month = {Jan}, pages = {198-203}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Bass JJ and Colomer-Rocher F and Baker RL and Carter AH and Jarnet MP and Woods EG} } @conference {39503, title = {A Comparison of the Danish, U.K., U.S. and New Zealand Systems of Mastitis Control}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {36}, year = {1976}, month = {Jan}, pages = {42-49}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Jasper DE} } @conference {39518, title = {Computer simulation of the feed requirements of shorn sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {36}, year = {1976}, month = {Jan}, pages = {161-169}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Faichney GJ and Black JL and Graham NMC} } @conference {39514, title = {Effect of Formaldehyde-treated casein and Methionine on the intake of silage by sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {36}, year = {1976}, month = {Jan}, pages = {127}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Lancaster RJ} } @conference {39521, title = {Effect of lambing date on the utilization of grass/clover and lucerne pastures during mating}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {36}, year = {1976}, month = {Jan}, pages = {184-189}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Thomson NA and Jagusch KT} } @conference {39519, title = {The effect of level of nutrition on the productivity of sheep of different genetic origin}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {36}, year = {1976}, month = {Jan}, pages = {170-178}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Joyce JP and Clarke JN and MacLean KS and Lynch RJ and Cox EH} } @conference {39513, title = {The effect on dairy cows and sheep performances of additives to high dry matter maize silage}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {36}, year = {1976}, month = {Jan}, pages = {120-126}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Hutton JB and Rattray PV} } @conference {39509, title = {The effects of heat treatment during processing in calf milk replacer quality}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {36}, year = {1976}, month = {Jan}, pages = {87-92}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Donnelly PE and Dean RJ and Kevey C} } @conference {39505, title = {Egg Transfer in Cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {36}, year = {1976}, month = {Jan}, pages = {58-66}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Struthers GA and Marshall DPJ} } @conference {39506, title = {Egg Transfers in Exotic Sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {36}, year = {1976}, month = {Jan}, pages = {67-75}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Tervit HR and Allison AJ and Smith JF and Harvey TM and Havik PG} } @conference {39512, title = {Environmental factors associated with summer-autumn growth rates of cattle and sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {36}, year = {1976}, month = {Jan}, pages = {103-119}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Scott JDJ and Rattray PV and Smeaton DC} } @conference {39517, title = {An evaluation of the role of systems modelling in an agricultural research programme}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {36}, year = {1976}, month = {Jan}, pages = {150-160}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Wright A and Baars JA and Bryant AM and Reardon TF and Saunders WMH and Wilson DA} } @conference {39531, title = {The fertility of hill country ewes mating at different stages of the joining period}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {36}, year = {1976}, month = {Jan}, pages = {252}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Knight TW} } @conference {39500, title = {The Importance of Pasture Pests in Animal Production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {36}, year = {1976}, month = {Jan}, pages = {12-22}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Pottinger RP} } @conference {39510, title = {The influence of breed of calf on the milk production of beef cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {36}, year = {1976}, month = {Jan}, pages = {93-98}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Nicol AM} } @conference {39508, title = {The influence of stubble height on digestibility, intake and liveweight gain on beef steers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {36}, year = {1976}, month = {Jan}, pages = {81-86}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Nicol AM and Clarke DG and Munro J and Smith MC} } @conference {39529, title = {Measurement of ovulation rates by laparoscopy and effects on reproductive performance}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {36}, year = {1976}, month = {Jan}, pages = {240-246}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Kelly RW and Allison AJ} } @conference {39511, title = {Measuring milk intake of lambs suckling grazing ewes by a double isotope method}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {36}, year = {1976}, month = {Jan}, pages = {99-102}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Wright DE and Wolff JE} } @conference {39524, title = {A new show class in an agricultural show}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {36}, year = {1976}, month = {Jan}, pages = {204-209}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Todhunter RC and Nicol AM} } @conference {39528, title = {Nutrition and embryo survival in the ewe}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {36}, year = {1976}, month = {Jan}, pages = {231-239}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Edey TN} } @conference {39527, title = {On-farm progeny testing for beef production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {36}, year = {1976}, month = {Jan}, pages = {222-230}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Everitt GC and Jury KE and Ward JDB} } @conference {39502, title = {Pasture Production in a Protein Extraction}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {36}, year = {1976}, month = {Jan}, pages = {30-41}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Ostrowski HT} } @conference {39520, title = {Performance of early-weaned lambs on lucerne and pasture}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {36}, year = {1976}, month = {Jan}, pages = {179-183}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Rattray PV and Morrison MCL and Farquhar PA} } @conference {39499, title = {Presidential Address: Some Aspects of the New Zealand Meat Industry}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {36}, year = {1976}, month = {Jan}, pages = {1-11}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Kirton AH} } @conference {39515, title = {Principles of Modelling Animal Systems}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {36}, year = {1976}, month = {Jan}, pages = {128-139}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Baldwin RL} } @conference {39522, title = {Red gut in lamb lucerne grazing trials at Lincoln}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {36}, year = {1976}, month = {Jan}, pages = {190-197}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Jagusch KT and Gumbrell RC and Dellow DW} } @conference {39532, title = {Relationship of parturient behaviour to reproductive efficiency of Finnsheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {36}, year = {1976}, month = {Jan}, pages = {253-257}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Holmes RJ} } @conference {39530, title = {Selection for fertility and response to PMSG in Romney ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {36}, year = {1976}, month = {Jan}, pages = {247-251}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Smith JF} } @conference {39501, title = {Selection Indices for Perendale Sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {36}, year = {1976}, month = {Jan}, pages = {23-29}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Elliott KH and Johnson DL} } @conference {39507, title = {The utilization of whole grain in maize silage by cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {36}, year = {1976}, month = {Jan}, pages = {76-80}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Bryant AM} } @conference {39526, title = {The value of on-farm performance selection of Angus and Hereford bulls}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {36}, year = {1976}, month = {Jan}, pages = {216-221}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Baker RL and Carter AH} } @conference {39465, title = {A.I. of sheep with frozen semen}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {35}, year = {1975}, month = {Jan}, pages = {71-77}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Smith JF and Boys PTS and Drost H and Wilson SG} } @conference {39463, title = {Anti-bacterial activity of seminal plasma and other tissues}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {35}, year = {1975}, month = {Jan}, pages = {61-64}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Shannon P and Curson B and Twomey A and Molan PC} } @conference {39472, title = {The carcass composition of Angus, Hereford x, Angus, Friesian x Angus, Charolaise x Angus and South Devon x Angus steers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {35}, year = {1975}, month = {Jan}, pages = {112-118}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Bass JJ and Baker RL and Carter AH and Jones KR} } @conference {39487, title = {Cerebrospinal fluid magnesium concentrations in hypomagnesaemic tetany}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {35}, year = {1975}, month = {Jan}, pages = {170-174}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Allsop TF and Pauki JV} } @conference {39477, title = {Combined effect of date of lambing and stocking rate on ewe and lamb liveweight during lactation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {35}, year = {1975}, month = {Jan}, pages = {144}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Trotter RW and Monteath MA and Kelly RW} } @conference {39479, title = {Comparative production of Romney sheep grazed with and without access to drinking water}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {35}, year = {1975}, month = {Jan}, pages = {150}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Clark VR and Jay NP} } @conference {39456, title = {The components of bovine saliva in relation to bloat}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {35}, year = {1975}, month = {Jan}, pages = {29-34}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McIntosh JT} } @conference {39460, title = {The distribution of Mg in the digesta of sheep fed fresh pasture}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {35}, year = {1975}, month = {Jan}, pages = {47-50}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Grace ND and Davies E} } @conference {39476, title = {The effect of lambing date on lamb growth rate, ewe liveweight and some observations on ewe milk production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {35}, year = {1975}, month = {Jan}, pages = {138-143}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Rattray PV and Morrison MCL and Oliver TW} } @conference {39468, title = {The effects of decreasing liveweight at mating on reproduction in Romney ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {35}, year = {1975}, month = {Jan}, pages = {91}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Dobbie JL and Welch RAS and Ackerley JG and Lake DE} } @conference {39481, title = {Effects of stage of growth, season, and conservation method on the nutritive value of lucerne}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {35}, year = {1975}, month = {Jan}, pages = {152-158}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Joyce JP and Brunswick LCF} } @conference {39466, title = {Egg transfer in cattle: Effect of hormonal treatment on synchronization of oestrus and ovarian response}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {35}, year = {1975}, month = {Jan}, pages = {78-82}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Tervit HR and Smith JF} } @conference {39489, title = {Environmental heterogeneity as a factor in group size determination among grazing sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {35}, year = {1975}, month = {Jan}, pages = {184-190}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Squires VR} } @conference {39480, title = {Estimates of genetic variation and covariation from New Zealand National Board Performance Testing Data}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {35}, year = {1975}, month = {Jan}, pages = {151}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Clarke JN and Adam JL and Hargreaves K} } @conference {39484, title = {Farm production experiments comparing formaldehyde-treated silage with conventional feeds for wintering yearling beef cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {35}, year = {1975}, month = {Jan}, pages = {167}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Binnie DB and Barry TN and Risk WH} } @conference {39482, title = {Formic acid as an additive for lucerne silage}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {35}, year = {1975}, month = {Jan}, pages = {159}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Lancaster RJ and Brunswick LCF and Wilson RK} } @conference {39491, title = {Grazing behaviour of sheep during summer and autumn in relation to facial eczema}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {35}, year = {1975}, month = {Jan}, pages = {198-203}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Keogh RG} } @conference {39478, title = {Growth, fertility and wool production of young Merino ewes fed different levels from 7 to 19 months of age}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {35}, year = {1975}, month = {Jan}, pages = {145-149}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Davis GH} } @conference {39474, title = {Growth rate and oestrous behaviour of Friesian, Hereford x Friesian, Simmental x Friesian and Angus heifers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {35}, year = {1975}, month = {Jan}, pages = {129-136}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Dalton DC and Jury KE and Hall DRH} } @conference {39473, title = {Growth rates of Friesian x Friesian, Hereford x Friesian and Simmental x Friesian steers in several environments}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {35}, year = {1975}, month = {Jan}, pages = {119-128}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Everitt GC and Jury KE and Ward JDB} } @conference {39494, title = {Handling deer run in confined areas}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {35}, year = {1975}, month = {Jan}, pages = {213-218}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Drew KR and Kelly RW} } @conference {39462, title = {Human error involved in dairy cow submission to artificial breeding}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {35}, year = {1975}, month = {Jan}, pages = {58-60}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Trim PN} } @conference {39459, title = {The influence of a protected tallow supplement on milk yield and composition}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {35}, year = {1975}, month = {Jan}, pages = {41-46}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Wilson GF and Brookes IM} } @conference {39493, title = {The influence of the senses of smell, sight and hearing on the sexual behaviour of rams}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {35}, year = {1975}, month = {Jan}, pages = {212}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Smith JF} } @conference {39464, title = {The inheritance of a A-Pyridine Nucleosidase in bull semen}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {35}, year = {1975}, month = {Jan}, pages = {65-70}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Giles KH and Macmillan KL} } @conference {39488, title = {Iron-induced hypocuprosis}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {35}, year = {1975}, month = {Jan}, pages = {175-183}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Campbell AG and Coup MR and Bishop WH and Wright DE} } @conference {39492, title = {Libido testing and subsequent mating performance in rams}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {35}, year = {1975}, month = {Jan}, pages = {204-211}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Kelly RW and Allison AJ and Shackell GH} } @conference {39486, title = {Liveweight and carcass responses of grazing steers to supplements in summer}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {35}, year = {1975}, month = {Jan}, pages = {169}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Reardon TF} } @conference {39461, title = {The NZSAP study group on internal parasites and animal production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {35}, year = {1975}, month = {Jan}, pages = {51-57}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Brunsdon RV} } @conference {39496, title = {Observations on the behaviour of single-suckled calves from birth to 120 days}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {35}, year = {1975}, month = {Jan}, pages = {221-230}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Nicol AM and Sharafeldin MA} } @conference {39470, title = {Onset of puberty in Angus, Friesian, Friesian x Angus, and Friesian x Jersey heifers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {35}, year = {1975}, month = {Jan}, pages = {97-102}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Pleasants AB and Hight GK and Barton RA} } @conference {39498, title = {Operant conditioning as a technique for the solution of practical problems in animal husbandry}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {35}, year = {1975}, month = {Jan}, pages = {238-247}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Whittlestone WG and Mullord MM and Cate LR and Waite T} } @conference {39485, title = {Pad Wintering of Beef Steers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {35}, year = {1975}, month = {Jan}, pages = {168}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Matthews WI} } @conference {39457, title = {Pasture composition and bloat}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {35}, year = {1975}, month = {Jan}, pages = {35}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Wright DE and Curtis MW} } @conference {39455, title = {Physiological genetics as a basis for the study of susceptibility to bloat in cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {35}, year = {1975}, month = {Jan}, pages = {21-28}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Cockrem FRM} } @conference {39467, title = {Preliminary studies on the efficiency of mating on ewe hoggets}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {35}, year = {1975}, month = {Jan}, pages = {83-90}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Allison AJ and Kelly RW and Lewis JS and Binnie DB} } @conference {39453, title = {Presidential Address: Farmer Motivation and Increased Animal Productivity}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {35}, year = {1975}, month = {Jan}, pages = {1-12}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McDonald MF} } @conference {39471, title = {Progeny testing Angus and Hereford bulls for growth performance}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {35}, year = {1975}, month = {Jan}, pages = {103-111}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Baker RL and Carter AH and Beatson PR} } @conference {39454, title = {Progress in identifying sources of animal variation in susceptibility to bloat}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {35}, year = {1975}, month = {Jan}, pages = {13-20}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Reid CSW and Gurnsey MP and Waghorn GC and Jones WT} } @conference {39475, title = {Relationships between milk yield, milk consumption and lamb growth in Romney, Dorset and Crossbred sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {35}, year = {1975}, month = {Jan}, pages = {137}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Geenty KG and Clarke JN and Wright DE and Wright GJ and Jones BA} } @conference {39490, title = {Sheep dispersal patterns on hill country: Techniques for study and analysis}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {35}, year = {1975}, month = {Jan}, pages = {191-197}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Kilgour R and Pearson AJ and de Langen H} } @conference {39495, title = {Social grooming patterns of dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {35}, year = {1975}, month = {Jan}, pages = {219-220}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Wood MT} } @conference {39497, title = {Social interactions among dairy cows during herd formation in spring}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {35}, year = {1975}, month = {Jan}, pages = {231-237}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Bremner KJ} } @conference {39469, title = {Studies on induced calving in cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {35}, year = {1975}, month = {Jan}, pages = {92-96}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McGowan LT and Welch RAS and Hunter JT} } @conference {39458, title = {The utilization of the energy of fresh milk by young Jersey and Friesian calves}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {35}, year = {1975}, month = {Jan}, pages = {36-40}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Holmes CW and Davey AWF and McLean NA and Jukes GC} } @conference {39483, title = {Winter performance of beef weaners fed untreated and formaldehyde-treated wilted lucerne silages and hay}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {35}, year = {1975}, month = {Jan}, pages = {160-166}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Scales GH and Barry TN} } @conference {39445, title = {Animal Health in a Feedlot}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {34}, year = {1974}, month = {Jan}, pages = {188-193}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Morris GR} } @conference {39420, title = {Anti-bacterial and anti-sperm effect of seminal plasma}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {34}, year = {1974}, month = {Jan}, pages = {61-64}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Shannon P and Twomey A and Curson B} } @conference {39441, title = {The application of artificial breeding as a reproductive technique in cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {34}, year = {1974}, month = {Jan}, pages = {158-166}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Macmillan KL} } @conference {39419, title = {Application of the egg transfer technique in cattle and sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {34}, year = {1974}, month = {Jan}, pages = {56-60}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Tervit HR and Rowson LEA and McDonald MF} } @conference {39452, title = {Beef Feedlotting - A Discussion Paper}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {34}, year = {1974}, month = {Jan}, pages = {254-261}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Monteath MA} } @conference {39450, title = {Beef market specifications as they affect the producer}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {34}, year = {1974}, month = {Jan}, pages = {241-246}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Bremner JP} } @conference {39425, title = {Beef production from untreated silage and silage treated with a mixture of formalin and formic acid}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {34}, year = {1974}, month = {Jan}, pages = {79-81}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Barry TN} } @conference {39414, title = {Behaviour of hill country sheep breeds during farming routines}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {34}, year = {1974}, month = {Jan}, pages = {28-36}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Whately J and Kilgour R and Dalton DC} } @conference {39439, title = {Breed differences in the tissue proportions and muscle distribution of meat animals}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {34}, year = {1974}, month = {Jan}, pages = {151}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Davies AS} } @conference {39451, title = {Business and management problems between killing and final product sales}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {34}, year = {1974}, month = {Jan}, pages = {247-253}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Trounce RH} } @conference {39440, title = {Communication of animal production information: An adviser{\textquoteright}s viewpoint}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {34}, year = {1974}, month = {Jan}, pages = {152-157}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Milligan KE} } @conference {39429, title = {Comparison between two methods of selecting 20-month steers for slaughter}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {34}, year = {1974}, month = {Jan}, pages = {96-99}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Nicol AM} } @conference {39413, title = {Comparison of pen and paddock systems for the pedigree mating of sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {34}, year = {1974}, month = {Jan}, pages = {23-27}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Clarke JN and Geenty KG and Bennett RG and Christensen GN and Wilson JA} } @conference {39411, title = {A comparison of the performance of Dorset, Corriedale and Romney sheep during lactation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {34}, year = {1974}, month = {Jan}, pages = {14-18}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Geenty KG and Jagusch KT} } @conference {39433, title = {Condition Scoring of Sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {34}, year = {1974}, month = {Jan}, pages = {114}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Milligan KE and Broadbent JS} } @conference {39410, title = {Crossbreeding, Interbreeding and Establishing a New Breed of Sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {34}, year = {1974}, month = {Jan}, pages = {11-13}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Coop IE} } @conference {39418, title = {Diagnosing pregnancy in ewes by rectal palpation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {34}, year = {1974}, month = {Jan}, pages = {55}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Ackerley JG and Welch RAS} } @conference {39422, title = {Effect of starvation on blood metabolites in pregnant sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {34}, year = {1974}, month = {Jan}, pages = {66}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Wolff JE and O{\textquoteright}Hara PJ and Kronfeld DS} } @conference {39423, title = {Energy requirements for pregnancy in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {34}, year = {1974}, month = {Jan}, pages = {67-77}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Rattray PV} } @conference {39447, title = {Feed intake and growth in New Zealand feedlots}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {34}, year = {1974}, month = {Jan}, pages = {206-214}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Thompson KF and Monteath MA} } @conference {39443, title = {Feedlot facilities}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {34}, year = {1974}, month = {Jan}, pages = {177-181}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Kerr RA} } @conference {39448, title = {Financial aspects of feedlot management in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {34}, year = {1974}, month = {Jan}, pages = {215-232}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McIvor AR and Jagusch KT and Charlton PJ} } @conference {39436, title = {Heat produced by young Jersey and Friesian calves in cold environments}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {34}, year = {1974}, month = {Jan}, pages = {132}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Holmes CW and McClean NR} } @conference {39421, title = {Hydrogenation of unsaturated fatty acids by ruminal fluid in vitro}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {34}, year = {1974}, month = {Jan}, pages = {65}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Payne E} } @conference {39435, title = {Hypocupriosis in dairy cattle in Northland}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {34}, year = {1974}, month = {Jan}, pages = {131}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Smith B} } @conference {39434, title = {Influence of birth date and dam{\textquoteright}s age on early growth in beef cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {34}, year = {1974}, month = {Jan}, pages = {115-130}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Baker RL and Carter AH and Cox EH and Templer HA} } @conference {39416, title = {Liveweight fertility relationships in Merino and half-bred ewes in a high country environment}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {34}, year = {1974}, month = {Jan}, pages = {45-50}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Allison AJ and Thompson KF and Davis GH} } @conference {39438, title = {Measurement of milk consumption in young ruminants using tritiated water}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {34}, year = {1974}, month = {Jan}, pages = {145-150}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Wright DE and Jones BA} } @conference {39427, title = {Measurement of rumen, methane kinetics and its application to bloat research}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {34}, year = {1974}, month = {Jan}, pages = {94}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Bryant AM and Murray RM} } @conference {39446, title = {Nutrition of Feedlot Beef Cattle in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {34}, year = {1974}, month = {Jan}, pages = {194-205}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Jagusch KT and McIvor AR} } @conference {39437, title = {Nutrition of the pre-ruminant calf}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {34}, year = {1974}, month = {Jan}, pages = {133-144}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Davey AWF} } @conference {39424, title = {Nutritive characteristics of maize silage and maize silage/grass rations for cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {34}, year = {1974}, month = {Jan}, pages = {78}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Waghorn GC and Wilson GF} } @conference {39428, title = {Nutritive values of lucerne leaf-protein concentrate and lupin-seed meal as protein supplements to barley diets for growing pigs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {34}, year = {1974}, month = {Jan}, pages = {95}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Carr JR and Pearson G} } @conference {39417, title = {Oestrus synchronization in cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {34}, year = {1974}, month = {Jan}, pages = {51-54}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Smith JF} } @conference {39426, title = {Plant tannins, bloat and nutritive value}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {34}, year = {1974}, month = {Jan}, pages = {82-93}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Reid CSW and Ulyatt MJ and Wilson JM} } @conference {39444, title = {Pollution problems associated with feedlot production of livestock}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {34}, year = {1974}, month = {Jan}, pages = {182-187}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Bell RG} } @conference {39415, title = {The present status of applied reproductive physiology in animal production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {34}, year = {1974}, month = {Jan}, pages = {37-44}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Robinson TJ} } @conference {39409, title = {Presidential Address: Crises, Consequences and Challenges for the New Zealand Animal Production Industry}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {34}, year = {1974}, month = {Jan}, pages = {1-10}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Clark VR} } @conference {39430, title = {Relationships of various parameters with the lambing performance of hoggets}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {34}, year = {1974}, month = {Jan}, pages = {100-101}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Winn GW and Cumberland GLB} } @conference {39432, title = {Reproductive Performance of Merino Ewes Dosed with Selenium Prior to Mating}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {34}, year = {1974}, month = {Jan}, pages = {103-113}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Scales GH} } @conference {39431, title = {Response to Oestradiol in Ewe Lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {34}, year = {1974}, month = {Jan}, pages = {102}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Whyman D} } @conference {39442, title = {Some techniques for increasing reproductive rates in sheep and their application in the industry}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {34}, year = {1974}, month = {Jan}, pages = {167-176}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Allison AJ} } @conference {39412, title = {Sources of variation for wool, body weight and oestrous characters in Romney hoggets}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {34}, year = {1974}, month = {Jan}, pages = {19-22}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Baker RL and Clarke JN and Carter AH} } @conference {39449, title = {Types of cattle to feed in relation to the needs of markets}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {34}, year = {1974}, month = {Jan}, pages = {233-240}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Barton RA} } @conference {39408, title = {Amino Acid Supplementation of Normal Hybrid and Opaque-2 Maize-Based Diets for Growing Pigs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {33}, year = {1973}, month = {Jan}, pages = {208}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Stables N} } @conference {39392, title = {Application of Dynamic Programming to the Culling Decision in Dairy Cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {33}, year = {1973}, month = {Jan}, pages = {141-147}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McArthur ATG} } @conference {39404, title = {Beef Cattle Improvement through Performance Recording and Selection}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {33}, year = {1973}, month = {Jan}, pages = {194-203}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Baker RL} } @conference {39390, title = {The behaviour of entire bulls of different ages at pasture}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {33}, year = {1973}, month = {Jan}, pages = {125-138}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Kilgour R and Campin DN} } @conference {39381, title = {Breeding for improved reproduction in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {33}, year = {1973}, month = {Jan}, pages = {18-25}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Ch{\textquoteright}ang TS} } @conference {39400, title = {Changes in Whole Body and Carcass Composition in Young Sheep During Weight Loss and Subsequent Regrowth}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {33}, year = {1973}, month = {Jan}, pages = {184-190}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Drew KR} } @conference {39402, title = {The Effect of Cortisol Acetate Administration on Growth and Carcass Quality of Lambs (Summary only)}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {33}, year = {1973}, month = {Jan}, pages = {192}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Purchas RW} } @conference {39403, title = {Effect of including quindoxin, a new chemical growth promoter, in pig and poultry rations}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {33}, year = {1973}, month = {Jan}, pages = {193}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Berwyn-Jones MD} } @conference {39388, title = {The effect of liveweight on the ovarian response and fertility of ewes treated with PMSG}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {33}, year = {1973}, month = {Jan}, pages = {114}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Allison AJ} } @conference {39397, title = {The effect of soil ingestion on the Mg and Ca metabolism of sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {33}, year = {1973}, month = {Jan}, pages = {164-165}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Grace ND and Healy WB} } @conference {39396, title = {Effects of Quantity and Quality of Feed on Gastric Secretion in the Sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {33}, year = {1973}, month = {Jan}, pages = {158-163}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McLeay LM and Titchen DA} } @conference {39383, title = {Factors affecting storage of semen}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {33}, year = {1973}, month = {Jan}, pages = {40-48}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Shannon P} } @conference {39407, title = {Feed Conversion Efficiency in High Liveweight Gain and Low Liveweight Gain Friesian Bulls}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {33}, year = {1973}, month = {Jan}, pages = {206-207}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Clark DA} } @conference {39406, title = {Grass Compared with Concentrates as an Early Weaning Feed for Friesian Bull Calves}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {33}, year = {1973}, month = {Jan}, pages = {205}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Byford MJ} } @conference {39399, title = {Measurement of the Milk Consumption of Suckling Beef Calves by an Isotope Dilution Method}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {33}, year = {1973}, month = {Jan}, pages = {176-183}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Nicol AM and Irvine CHG} } @conference {39380, title = {Memorial Address: John Morris Ranstead}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {33}, year = {1973}, month = {Jan}, pages = {11-17}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Ward AH} } @conference {39379, title = {A new look for Animal Production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {33}, year = {1973}, month = {Jan}, pages = {1-10}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Everitt GC} } @conference {39385, title = {Nutritional and physiological developments in reproduction of pigs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {33}, year = {1973}, month = {Jan}, pages = {62-86}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Shearer IJ and Adam JL} } @conference {39387, title = {Observations on Yearling Mating of Beef Cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {33}, year = {1973}, month = {Jan}, pages = {94-113}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Carter AH and Cox EH} } @conference {39389, title = {Premating Treatment of Breeding Ewes with Thiabendazole}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {33}, year = {1973}, month = {Jan}, pages = {115-124}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Holmden JH and McMullan MJ and Cairns GC and Leaning WHD} } @conference {39393, title = {Price: Liveweight Relationships at Beef Weaner Sales}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {33}, year = {1973}, month = {Jan}, pages = {148}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Thompson KF} } @conference {39394, title = {Quantitative Aspects of Fermentation in the Gastro-Intestinal Tract of Sheep Fed Fresh Herbage}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {33}, year = {1973}, month = {Jan}, pages = {149-156}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Ulyatt MJ and Dellow DW and Egan AR and Walker DJ} } @conference {39382, title = {Recent advances in reproductive physiology: Implications for control of fertility and fecundity of sheep and cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {33}, year = {1973}, month = {Jan}, pages = {26-39}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McDonald MF and Cumming IA} } @conference {39405, title = {Repeated Gonadotrophic Stimulation of Ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {33}, year = {1973}, month = {Jan}, pages = {204}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Clarke IJ} } @conference {39386, title = {Some aspects of Anoestrus in New Zealand dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {33}, year = {1973}, month = {Jan}, pages = {87-93}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Fielden ED and Macmillan KL} } @conference {39395, title = {Some Aspects of Feeding Whole Wheat Grain to Young Sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {33}, year = {1973}, month = {Jan}, pages = {157}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Bigham ML} } @conference {39391, title = {Some Aspects of Sheep Group Breeding Schemes in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {33}, year = {1973}, month = {Jan}, pages = {139-140}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McConnell GR and Thompson KF} } @conference {39398, title = {Ten- and Eighteen-Week Suckling of Friesian Steers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {33}, year = {1973}, month = {Jan}, pages = {166-175}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Smith ME and Callow C and McSweeney BJ} } @conference {39384, title = {Why do bulls differ in fertility?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {33}, year = {1973}, month = {Jan}, pages = {49-61}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Macmillan KL} } @conference {39401, title = {Yellow Fat in Lambs (Summary only)}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {33}, year = {1973}, month = {Jan}, pages = {191}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Kirton AH and Crane B and Paterson DJ and Clare NT} } @conference {39363, title = {Breeding Dairy Cattle with Reduced Susceptibility to Bloat}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {32}, year = {1972}, month = {Jan}, pages = {96-98}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Reid CSW and Clarke RTJ and Gurnsey MP and Hungate RE and Macmillan KL} } @conference {39353, title = {Calf Growth and Lifetime Performance of Beef Cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {32}, year = {1972}, month = {Jan}, pages = {20-25}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Everitt GC} } @conference {39364, title = {Current Levels of Performance in the Ruakura Fertility Flock of Romney Sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {32}, year = {1972}, month = {Jan}, pages = {99-111}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Clarke JN} } @conference {39371, title = {Developments and future trends in non-animal sources of protein}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {32}, year = {1972}, month = {Jan}, pages = {147-159}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Hove EL} } @conference {39356, title = {The Effect of Formaldehyde Treatment on the Chemical Composition, Apparent Digestibility and Voluntary Intake of Silage by Sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {32}, year = {1972}, month = {Jan}, pages = {48-49}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Barry TN and Fennessy PF and Duncan SJ} } @conference {39365, title = {The effect of mating pressure on characteristics of the ejaculate in rams and on reproductive performance in ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {32}, year = {1972}, month = {Jan}, pages = {112-113}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Allison AJ} } @conference {39354, title = {Effects of Pre-Weaning Nutrition on Subsequent Growth Rate, Feed Conversion Efficiency and Carcass Composition of Identical Twin Steers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {32}, year = {1972}, month = {Jan}, pages = {26-38}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Reardon TF and Everitt GC} } @conference {39358, title = {Feeding Value of Lucerne}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {32}, year = {1972}, month = {Jan}, pages = {54-63}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Joyce JP and Brunswick L and Parker J} } @conference {39373, title = {Food Protein Products from Milk}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {32}, year = {1972}, month = {Jan}, pages = {170-177}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McGillivray WA} } @conference {39352, title = {Friesian and Beef Breed Performance in an Improved Tussock Environment}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {32}, year = {1972}, month = {Jan}, pages = {19}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Lewis KHC and Davis GH} } @conference {39366, title = {Growth rate selection in Southdown sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {32}, year = {1972}, month = {Jan}, pages = {114}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Hart DS} } @conference {39361, title = {Influence of Experimental Design in Measuring the Voluntary Intake of Grazing Sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {32}, year = {1972}, month = {Jan}, pages = {85-86}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Ulyatt MJ} } @conference {39368, title = {A management information system for a Broiler Hatchery}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {32}, year = {1972}, month = {Jan}, pages = {123-131}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McArthur ATG and Le Page DK} } @conference {39378, title = {Meat and Meat Products}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {32}, year = {1972}, month = {Jan}, pages = {226-234}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Pearson AM} } @conference {39351, title = {Meat Production from Friesian and Angus Bulls}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {32}, year = {1972}, month = {Jan}, pages = {11-18}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Dalton DC and Everitt GC} } @conference {39372, title = {Milk Protein Production: An analysis of New Zealand{\textquoteright}s present and potential capabilities}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {32}, year = {1972}, month = {Jan}, pages = {160-169}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Hutton JB} } @conference {39362, title = {Plasma and Urinary Metabolites as Indices of N Utilization in Sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {32}, year = {1972}, month = {Jan}, pages = {87-95}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Egan AR} } @conference {39350, title = {Presidential Address: Extension in Animal Production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {32}, year = {1972}, month = {Jan}, pages = {1-10}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Clifford HJ} } @conference {39357, title = {Production of Prime Lambs from Coopworth Ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {32}, year = {1972}, month = {Jan}, pages = {50-53}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McConnell GR and Jagusch KT} } @conference {39375, title = {Protein Production from Beef}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {32}, year = {1972}, month = {Jan}, pages = {185-203}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Everitt GC} } @conference {39376, title = {Protein Production from Pigs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {32}, year = {1972}, month = {Jan}, pages = {204-214}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Carr JR} } @conference {39377, title = {Protein Production from Poultry}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {32}, year = {1972}, month = {Jan}, pages = {215-225}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Patchell MR and Thorstensen SD} } @conference {39374, title = {Protein Production from Sheep, Goats and Deer}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {32}, year = {1972}, month = {Jan}, pages = {178-184}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Coop IE} } @conference {39355, title = {The Qualities of Ram Carcasses}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {32}, year = {1972}, month = {Jan}, pages = {39-47}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Kirton AH and Paterson DJ} } @conference {39359, title = {Review of Field Research Section Fertilizer x Stocking Rate Grazing Trials in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {32}, year = {1972}, month = {Jan}, pages = {64-76}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Joblin ADH and Blackmore LW and Bircham JS and Cossens GG and Cumberland GLB and O{\textquoteright}Connor MB and Thomson NA and Smith RG and Wright DF} } @conference {39369, title = {Some observations on the suckling activity of calves on nurse cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {32}, year = {1972}, month = {Jan}, pages = {132-138}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Kilgour R} } @conference {39370, title = {Sources of world food protein and the New Zealand contribution}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {32}, year = {1972}, month = {Jan}, pages = {139-146}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Whittlestone WG} } @conference {39360, title = {Studies on the Movement of Mg, Ca, P, Na and K Across the Gut Wall of Sheep Fed Fresh Pasture}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {32}, year = {1972}, month = {Jan}, pages = {77-84}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Grace ND} } @conference {39367, title = {A survey of lambing practices in stud sheep flocks in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {32}, year = {1972}, month = {Jan}, pages = {115-122}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Welch RAS and Kilgour R} } @conference {39342, title = {Breeds of Sire for Export Lamb Production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {31}, year = {1971}, month = {Jan}, pages = {175}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Kirton AH and Carter AH and Clarke JN and Sinclair DP and Jury KE} } @conference {39321, title = {Calf Rearing by Multiple Suckling and the Effects on Lactation Performance of the Cow}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {31}, year = {1971}, month = {Jan}, pages = {22-40}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Everitt GC and Phillips DSM} } @conference {39329, title = {A Comparison of Phosphorus Responses in Pasture and Sheep, and Effects of Increased Grazing Pressure in a Dry Season}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {31}, year = {1971}, month = {Jan}, pages = {66-73}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Cumberland GLB and Dyson CB and Honore EN} } @conference {39325, title = {Compensatory Growth in Yearling Beef Cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {31}, year = {1971}, month = {Jan}, pages = {51-61}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Scales GH and Lewis KHC} } @conference {39338, title = {Computer Systems for Management Information in Primary Production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {31}, year = {1971}, month = {Jan}, pages = {135-141}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Cockrem FRM} } @conference {39341, title = {Crossing Experiments for the Utilization of Sheep Breeds in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {31}, year = {1971}, month = {Jan}, pages = {164-174}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Clarke JN} } @conference {39327, title = {Digestibility of Protein-Extracted Forages}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {31}, year = {1971}, month = {Jan}, pages = {64}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Vartha EW and Allison RM} } @conference {39345, title = {Early Lamb Production and its Place in New Zealand Farming}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {31}, year = {1971}, month = {Jan}, pages = {186}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Welch RAS and Duder FR and Tervit HR} } @conference {39335, title = {Effect of Nutrition of the Dam on Wool Follicle Development of Corriedale Lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {31}, year = {1971}, month = {Jan}, pages = {114-120}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Williams PM and Henderson AE} } @conference {39323, title = {Effect of Pre-Slaughter Starvation on Weight-Loss in Cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {31}, year = {1971}, month = {Jan}, pages = {42}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Kirton AH and Paterson DJ} } @conference {39334, title = {The Effect of Sub-Maintenance Feeding of Ewes During Mid-Pregnancy on Lamb and Wool Production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {31}, year = {1971}, month = {Jan}, pages = {105-113}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Monteath MA} } @conference {39337, title = {The Effect of Treating Forage with Formaldehyde During Haymaking and Methionine Administration During Feeding on the Digestion and Utilization of Energy and Nitrogen by Sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {31}, year = {1971}, month = {Jan}, pages = {129-134}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Barry TN} } @conference {39340, title = {Effectiveness of Growth Performance Selection in Cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {31}, year = {1971}, month = {Jan}, pages = {151-163}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Carter AH} } @conference {39320, title = {Effects of Varying the Environment on the Behaviour and Performance of Dairy Cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {31}, year = {1971}, month = {Jan}, pages = {10-21}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Albright JL} } @conference {39347, title = {Feed Requirements of Beef Cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {31}, year = {1971}, month = {Jan}, pages = {196-210}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Joyce JP} } @conference {39332, title = {Feeding Value of Barley for Sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {31}, year = {1971}, month = {Jan}, pages = {92-96}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Joyce JP} } @conference {39346, title = {Methods of Expressing Feed Requirements}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {31}, year = {1971}, month = {Jan}, pages = {187-195}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Bryant AM} } @conference {39322, title = {Mismothering in Romney Sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {31}, year = {1971}, month = {Jan}, pages = {41}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Welch RAS and Kilgour R} } @conference {39348, title = {Nutrient Requirements of New Zealand Dairy Cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {31}, year = {1971}, month = {Jan}, pages = {211-223}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Hutton JB} } @conference {39333, title = {Nutrition of Halfbred Ewes on Improved Tussock Grassland}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {31}, year = {1971}, month = {Jan}, pages = {97-104}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Vartha EW and Clifford PTP} } @conference {39336, title = {Nutrition of the Young Growing Lamb: Studies at Lincoln College}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {31}, year = {1971}, month = {Jan}, pages = {121-128}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Jagusch KT and Mitchell RM and McConnell GR and Fennessy PF and Woodlock MR and Jay NPW} } @conference {39349, title = {The Nutritional Requirements of Grazing Sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {31}, year = {1971}, month = {Jan}, pages = {224-234}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Jagusch KT and Coop IE} } @conference {39326, title = {Preliminary Studies of Digestion in the Hindgut of the Sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {31}, year = {1971}, month = {Jan}, pages = {62-63}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Reid CSW and MacRae JC and Dellowes DW and Clarke RTJ and Whyburn RS} } @conference {39319, title = {Presidential Address: Improving Beef Cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {31}, year = {1971}, month = {Jan}, pages = {1-9}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Shannon P} } @conference {39324, title = {Reciprocal Crossbreeding of Friesian and Angus Cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {31}, year = {1971}, month = {Jan}, pages = {43-50}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Hight GK and Everitt GC and Jury KE} } @conference {39343, title = {Reproductive Differences between Border Leicester x Romney and Romney Two-Tooth Ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {31}, year = {1971}, month = {Jan}, pages = {176-179}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Larsen WA and McDonald MF} } @conference {39330, title = {The Sites of Digestion of Fresh Pasture Species in the Gastro-Intestinal Tracts of Sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {31}, year = {1971}, month = {Jan}, pages = {74-81}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Ulyatt MJ and MacRae JC} } @conference {39328, title = {Some Effects of Anthelmintic Dosing on the Mineral Status of Hoggets}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {31}, year = {1971}, month = {Jan}, pages = {65}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Andrews ED and Hogan KG and Brunsdon RV} } @conference {39331, title = {Studies on the Hydrolysis by Carbohydrates of Plant Cell-Wall Constituents in Relation to Pasture Quality}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {31}, year = {1971}, month = {Jan}, pages = {82-91}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Bailey RW and Jones DIH} } @conference {39339, title = {Two New Methods of Teaching Animal Breeding with Potential in Agricultural Extension}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {31}, year = {1971}, month = {Jan}, pages = {142-150}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Fawns RA and McArthur ATG} } @conference {39344, title = {The Use of an Ultrasonic Device for Detection of Pregnancy in the Ewe}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {31}, year = {1971}, month = {Jan}, pages = {180-185}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Allison AJ} } @conference {39295, title = {The application of performance testing to pig improvement in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {30}, year = {1970}, month = {Jan}, pages = {41-50}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Quartermain AR} } @conference {39310, title = {Classification and grading of beef and lamb in the United States of America}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {30}, year = {1970}, month = {Jan}, pages = {172-185}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Barton RA} } @conference {39308, title = {Classification and grading of beef and veal carcasses}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {30}, year = {1970}, month = {Jan}, pages = {144-160}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Everitt GC and Evans ST} } @conference {39309, title = {Classification and grading of pig carcasses}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {30}, year = {1970}, month = {Jan}, pages = {161-171}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Adam JL} } @conference {39297, title = {Drenching of pregnant ewes and its effect on their wool production and lamb growth rates}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {30}, year = {1970}, month = {Jan}, pages = {52-64}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Leaning WHD and Cairns GC and McKenzie JK and Hunter WR} } @conference {39314, title = {The effect of feeding formaldehyde-treated casein and lucerne meal to sheep on nitrogen metabolism and wool production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {30}, year = {1970}, month = {Jan}, pages = {216-217}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Barry TN} } @conference {39303, title = {Effect of pre-weaning plane of nutrition on subsequent growth and carcass quality of lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {30}, year = {1970}, month = {Jan}, pages = {106-115}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Kirton AH} } @conference {39299, title = {The effect of storage time on the voluntary intake of silage by sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {30}, year = {1970}, month = {Jan}, pages = {77-89}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Bryant AM and Lancaster RJ} } @conference {39293, title = {Efficiency of feed conversion in Friesian and Angus steers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {30}, year = {1970}, month = {Jan}, pages = {23-31}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Joblin ADH} } @conference {39318, title = {Evaluation of speakers at the 1970 conference}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {30}, year = {1970}, month = {Jan}, pages = {249-257}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Clifford HJ} } @conference {39294, title = {The feed intake of Friesian dairy beef animals}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {30}, year = {1970}, month = {Jan}, pages = {32-40}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {MacLean KS and Joyce JP and Rattray PV} } @conference {39317, title = {Free amino acids in the plasma of sheep fed supplementary protein, with particular reference to e-N-methyl lysine}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {30}, year = {1970}, month = {Jan}, pages = {240-248}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Fraser IEB and Haden DD} } @conference {39307, title = {Grading of lamb and mutton carcasses}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {30}, year = {1970}, month = {Jan}, pages = {130-143}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Kirton AH and Jury KE} } @conference {39305, title = {The influence if protein supplements on milk yield and composition}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {30}, year = {1970}, month = {Jan}, pages = {123-127}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Wilson GF} } @conference {39289, title = {Ingested soil as a possible source of elements for grazing animals}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {30}, year = {1970}, month = {Jan}, pages = {11-19}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Healy WB} } @conference {39302, title = {The intake and utilization of milk and grass by lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {30}, year = {1970}, month = {Jan}, pages = {94-105}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Joyce JP and Rattray PV} } @conference {39291, title = {Magnesium absorption in the digestive tract of sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {30}, year = {1970}, month = {Jan}, pages = {21}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Grace ND} } @conference {39301, title = {The nutritive value of the residue from protein-extracted herbage}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {30}, year = {1970}, month = {Jan}, pages = {92-93}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Ulyatt MJ} } @conference {39292, title = {Oestrogenic activity in New Zealand pastures and some effects of oestrogen injections on Mastitis and fertility}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {30}, year = {1970}, month = {Jan}, pages = {22}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Welch RAS and Tervit HR} } @conference {39304, title = {Pasture type and lamb carcass composition}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {30}, year = {1970}, month = {Jan}, pages = {116-122}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Jagusch KT and Nicol AM} } @conference {39288, title = {Presidential Address: Animal Production in a hungry world}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {30}, year = {1970}, month = {Jan}, pages = {1-10}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Whittlestone WG} } @conference {39300, title = {The production of volatile fatty acids in sheep on different pasture types}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {30}, year = {1970}, month = {Jan}, pages = {90-91}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Mackintosh JB and Ulyatt MJ} } @conference {39311, title = {Protein Supplementation and Wool Growth}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {30}, year = {1970}, month = {Jan}, pages = {186-201}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Henderson AE and Bryden JMG and Mazzitelli FE and Milligan KE} } @conference {39290, title = {Saline drinking water for sheep: Some aspects of the ingestion of sodium chloride solutions}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {30}, year = {1970}, month = {Jan}, pages = {20}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Potter BJ and Walker DJ and Jones GB and Reid CSW} } @conference {39316, title = {Some effects on food intake of infusions of amino acid-containing materials}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {30}, year = {1970}, month = {Jan}, pages = {227-239}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Bryant AM and Titchen DA and Reid CSW} } @conference {39306, title = {Specifications for the classification and grading of meat carcasses in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {30}, year = {1970}, month = {Jan}, pages = {128-129}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Ryan B} } @conference {39296, title = {Storage of ram semen at ambient temperatures}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {30}, year = {1970}, month = {Jan}, pages = {51}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Welch RAS and Shannon P} } @conference {39298, title = {Stress in sheep resulting from management practices}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {30}, year = {1970}, month = {Jan}, pages = {65-76}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Kilgour R and de Langen H} } @conference {39315, title = {Studies on the intestinal digestion of nitrogen by sheep fed formalin-treated casein diets}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {30}, year = {1970}, month = {Jan}, pages = {218-226}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {MacRae JC} } @conference {39312, title = {Wool growth in relation to dietary protein level}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {30}, year = {1970}, month = {Jan}, pages = {202-208}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Carrico RG and Cockrem FRM and Wickham GA} } @conference {39313, title = {Wool growth in relation to sulphur-containing amino acid administration to sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {30}, year = {1970}, month = {Jan}, pages = {209-215}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Wickham GA} } @conference {39262, title = {Antibodies in Brucellosis}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {29}, year = {1969}, month = {Jan}, pages = {14-21}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Rice CE} } @conference {39277, title = {Baby beef without concentrates - A Feasibility Study Baby beef without concentrates - A Feasibility Study}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {29}, year = {1969}, month = {Jan}, pages = {137-146}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Joblin ADH} } @conference {39276, title = {Biochemistry of Sporidesmin}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {29}, year = {1969}, month = {Jan}, pages = {132-136}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Wright DE} } @conference {39266, title = {The cleaning of milking machines and milk quality}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {29}, year = {1969}, month = {Jan}, pages = {48-53}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Twomey A} } @conference {39267, title = {Comparative growth performance of Jersey, Friesian and Ayrshire bulls on pasture}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {29}, year = {1969}, month = {Jan}, pages = {54-62}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Carter AH} } @conference {39286, title = {The effect of plane of nutrition and feeding Formalin-treated casein on the production, fibre diameter and tensile strength of wool}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {29}, year = {1969}, month = {Jan}, pages = {218}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Barry TN} } @conference {39280, title = {Effects of level of stocking rate on conversion efficiency and productivity of dairy beef cattle and breeding ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {29}, year = {1969}, month = {Jan}, pages = {176}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Joyce JP and Rattray PV} } @conference {39281, title = {The effects of pre-lambing Anthelmintic drenching on production of ewes and the development of worm parasitism in lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {29}, year = {1969}, month = {Jan}, pages = {177-191}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Lewis KHC and Stauber VV} } @conference {39271, title = {Egg transplantation studies in Romney ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {29}, year = {1969}, month = {Jan}, pages = {95-101}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McDonald MF} } @conference {39278, title = {Genetic and environmental effects on beef production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {29}, year = {1969}, month = {Jan}, pages = {147-163}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Everitt GC and Evans ST and Franks M} } @conference {39268, title = {Genetic improvement of dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {29}, year = {1969}, month = {Jan}, pages = {63-76}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Johansson I} } @conference {39275, title = {The influence of dietary factors and drug-processing enzymes on Sporidesmin poisoning in sheep - A Preliminary Report}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {29}, year = {1969}, month = {Jan}, pages = {125-131}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Mortimer PH} } @conference {39284, title = {An investigation of the relationships between body temperature and implantation and lambing rates in the New Zealand Romney ewe}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {29}, year = {1969}, month = {Jan}, pages = {195-207}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Cockrem FRM and McDonald MF} } @conference {39287, title = {Lamb Mortality in Hill Country Flocks}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {29}, year = {1969}, month = {Jan}, pages = {219-232}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Hight GK and Jury KE} } @conference {39263, title = {Machine milking and Mastitis}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {29}, year = {1969}, month = {Jan}, pages = {22-25}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Whittlestone WG and Fell LR} } @conference {39274, title = {The nutritive value of Snow Tussock (Chionochloa zotov)}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {29}, year = {1969}, month = {Jan}, pages = {124}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {MacRae JC} } @conference {39283, title = {Observations on the fertility of the two-tooth New Zealand Romney ewe}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {29}, year = {1969}, month = {Jan}, pages = {194}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Wodzicka-Tomaszewska M and Welch RAS} } @conference {39282, title = {Oestrous activity and lamb production of the N.Z. Romney ewe}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {29}, year = {1969}, month = {Jan}, pages = {192-193}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Quinlivan TD and Martin CA} } @conference {39261, title = {Presidential Address: An approach to teaching animal science in the university}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {29}, year = {1969}, month = {Jan}, pages = {1-13}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Hollard MG} } @conference {39273, title = {Progress in defining the differences in nutritive value to sheep of Perennial Ryegrass, Short-Rotation Ryegrass and White Clover}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {29}, year = {1969}, month = {Jan}, pages = {114-123}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Ulyatt MJ} } @conference {39269, title = {Research on current sire proving procedures}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {29}, year = {1969}, month = {Jan}, pages = {77-86}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Evans DA} } @conference {39285, title = {Some effects of an increased stocking level on wool growth}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {29}, year = {1969}, month = {Jan}, pages = {208-217}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Sumner RMW and Wickham GA} } @conference {39279, title = {Some factors affecting yellow fat colour in cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {29}, year = {1969}, month = {Jan}, pages = {164-175}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Morgan JHL and Pickering FS and Everitt GC} } @conference {39264, title = {Some recent research on milking machine design}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {29}, year = {1969}, month = {Jan}, pages = {26-36}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Phillips DSM and Copeman PJA} } @conference {39265, title = {Surveys on farm milking shed performance}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {29}, year = {1969}, month = {Jan}, pages = {37-47}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Clifford HJ} } @conference {39270, title = {Transport of sheep ova in rabbits}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {29}, year = {1969}, month = {Jan}, pages = {87-94}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Welch RAS} } @conference {39272, title = {The utilization of Perennial Ryegrass and White Clover by young sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {29}, year = {1969}, month = {Jan}, pages = {102-113}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Rattray PV and Joyce JP} } @conference {39240, title = {Advances in Semen Dilution}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {28}, year = {1968}, month = {Jan}, pages = {23-31}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Shannon P} } @conference {39245, title = {Animal and pasture production as indices of fertilizer maintenance requirements}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {28}, year = {1968}, month = {Jan}, pages = {53-64}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Scott RS} } @conference {39239, title = {Autotransplantation of Endocrine Glands in Sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {28}, year = {1968}, month = {Jan}, pages = {22}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Hart DS and Beaven DW and Espiner EA and Perry EG and Holland GW} } @conference {39258, title = {Beef production from Jersey steers grazed in three environments}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {28}, year = {1968}, month = {Jan}, pages = {158-176}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Morgan JHL and Everitt GC} } @conference {39259, title = {Beef production with Friesian and Friesian-cross cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {28}, year = {1968}, month = {Jan}, pages = {177-179}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Hollard MG} } @conference {39242, title = {Body composition studies with the milk-fed lamb}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {28}, year = {1968}, month = {Jan}, pages = {40}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Jagusch KT} } @conference {39244, title = {Calculation of the digestibility and the starch equivalent value of herbages from chemical analyses}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {28}, year = {1968}, month = {Jan}, pages = {49-52}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Gaillard BDE} } @conference {39260, title = {A comparison between Friesian, Jersey and Friesian-Jersey cross steers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {28}, year = {1968}, month = {Jan}, pages = {180-181}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Barton RA and Jones CF and Donaldson JL and Barnes FR and Evans DA and Clifford HJ} } @conference {39238, title = {Comparison of mice, guinea-pigs and sheep as test animals for bioassay of oestrogenic pasture legumes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {28}, year = {1968}, month = {Jan}, pages = {11-21}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Morley FHW and Bennett D and Braden AWH and Turnbull KE and Axelsen A} } @conference {39253, title = {Distribution of Spermatozoa in the Reproductive Tract of the Romney ewe}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {28}, year = {1968}, month = {Jan}, pages = {120}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Lang DR and Oh YK} } @conference {39247, title = {The effect of two different planes of nutrition from conception to four years of age on the maintenance requirements and on the efficiency of wool growth}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {28}, year = {1968}, month = {Jan}, pages = {74-82}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Wodzicka-Tomaszewska M and Bigham ML and Kirton AH and Duganzich DM} } @conference {39254, title = {Future requirements for expanded beef production in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {28}, year = {1968}, month = {Jan}, pages = {121-130}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Ward FL} } @conference {39241, title = {Genetic implications of advances in semen dilution}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {28}, year = {1968}, month = {Jan}, pages = {32-39}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Stichbury JW} } @conference {39255, title = {Hill country beef cattle research at Whatawhata}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {28}, year = {1968}, month = {Jan}, pages = {131-144}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Hight GK} } @conference {39252, title = {The influence of liveweight on ovulation rate in the ewe}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {28}, year = {1968}, month = {Jan}, pages = {115-119}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Allison AJ} } @conference {39257, title = {Meat meal in early weaning calf concentrate mixtures}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {28}, year = {1968}, month = {Jan}, pages = {157}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Khouri RH} } @conference {39237, title = {Presidential Address: Agricultural Science in the Human Environment}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {28}, year = {1968}, month = {Jan}, pages = {1-10}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Campbell AG} } @conference {39246, title = {Prospects for high production from Canterbury Plains pastures}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {28}, year = {1968}, month = {Jan}, pages = {65-73}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Vartha EW and O{\textquoteright}Connor KF} } @conference {39243, title = {Some factors influencing the growth of lambs on irrigated pasture}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {28}, year = {1968}, month = {Jan}, pages = {41-48}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Walker SD} } @conference {39251, title = {Synchronization of oestrus in ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {28}, year = {1968}, month = {Jan}, pages = {114}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Coop IE and Clark VR} } @conference {39249, title = {Winter feeding hoggets}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {28}, year = {1968}, month = {Jan}, pages = {94-106}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Drew KR} } @conference {39256, title = {Winter feeding trials with beef cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {28}, year = {1968}, month = {Jan}, pages = {145-156}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Joblin ADH} } @conference {39248, title = {Winter supplementation of Merino ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {28}, year = {1968}, month = {Jan}, pages = {83-93}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Lewis KHC} } @conference {39250, title = {Wool follicle and fleece characters of F1 and F2 Border Leicester x Romney sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {28}, year = {1968}, month = {Jan}, pages = {107-113}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Henderson AE} } @conference {39217, title = {Age at puberty, length of breeding season and ovulation rate in Romney Marsh and Border Leicester x Romney Marsh hoggets}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {27}, year = {1967}, month = {Jan}, pages = {48}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Lang DR and Hight GK} } @conference {39220, title = {An airflow calorimeter for the measurement of the sensible heat loss of animals}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {27}, year = {1967}, month = {Jan}, pages = {69-70}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Cockrem F and Clarke RM} } @conference {39223, title = {Birth weights of dairy, beef and dairy-beef calves}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {27}, year = {1967}, month = {Jan}, pages = {73-79}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Everitt GC} } @conference {39230, title = {Breeding for improved quality and quantity of forage for the grazing animal}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {27}, year = {1967}, month = {Jan}, pages = {139-145}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Barclay PC} } @conference {39228, title = {Effect of soil type on uptake of magnesium by pasture plants}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {27}, year = {1967}, month = {Jan}, pages = {121-125}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McNaught KJ and Ludecke TE} } @conference {39235, title = {The effect of temperature on body growth and other traits of open- and woolly-faced Romney lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {27}, year = {1967}, month = {Jan}, pages = {193-209}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Cockrem F} } @conference {39232, title = {The efficiency of feed utilization}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {27}, year = {1967}, month = {Jan}, pages = {154-165}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Coop IE} } @conference {39229, title = {Increasing fodder production for the grazing animal}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {27}, year = {1967}, month = {Jan}, pages = {126-138}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Campbell AG} } @conference {39227, title = {Ingestion of soil by sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {27}, year = {1967}, month = {Jan}, pages = {109-120}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Healy WB} } @conference {39225, title = {Interrupted pregnancy in the dairy cow}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {27}, year = {1967}, month = {Jan}, pages = {93-100}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Moller K} } @conference {39218, title = {Observations on the prediction of lambing dates}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {27}, year = {1967}, month = {Jan}, pages = {49-51}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Phillips TO} } @conference {39215, title = {Performance recording of sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {27}, year = {1967}, month = {Jan}, pages = {29-45}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Clarke EA} } @conference {39216, title = {Population structure and breeding for genetic improvement}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {27}, year = {1967}, month = {Jan}, pages = {46-47}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Quartermain AR} } @conference {39224, title = {A possible use of computers in animal production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {27}, year = {1967}, month = {Jan}, pages = {80-92}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Dick ID and Vignaux GA} } @conference {39213, title = {Presidential Address: Agricultural development and research in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {27}, year = {1967}, month = {Jan}, pages = {1-16}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Hutton JB} } @conference {39214, title = {Principles and practices used in livestock improvement programmes in the USA}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {27}, year = {1967}, month = {Jan}, pages = {17-28}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Chapman AB} } @conference {39231, title = {Progress in pasture plant physiology}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {27}, year = {1967}, month = {Jan}, pages = {146-153}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Langer RHM} } @conference {39219, title = {Residual effects of prenatal nutrition on the postnatal performance of Merino sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {27}, year = {1967}, month = {Jan}, pages = {52-68}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Everitt GC} } @conference {39226, title = {Soils and Animal Production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {27}, year = {1967}, month = {Jan}, pages = {101-108}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Saunders WMH} } @conference {39221, title = {Taste panel relationships}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {27}, year = {1967}, month = {Jan}, pages = {71}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Morgan JHL} } @conference {39234, title = {The use of steady state feeding system in nutrition experiments with ruminants}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {27}, year = {1967}, month = {Jan}, pages = {181-192}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Ulyatt MJ} } @conference {39233, title = {Use of the comparative slaughter technique to estimate the nutritive value of pasture for hoggets}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {27}, year = {1967}, month = {Jan}, pages = {166-180}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Joyce JP and Newth RP} } @conference {39222, title = {The utilization of lactose by the growing pig}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {27}, year = {1967}, month = {Jan}, pages = {72}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Shearer IJ and Dunkin AC} } @conference {39236, title = {The winter nutrition of Romney hoggets}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {27}, year = {1967}, month = {Jan}, pages = {210-222}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Drew KR} } @conference {39210, title = {An attempt to control hydatid disease in animals in an isolated region of New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {26}, year = {1966}, month = {Jan}, pages = {161-164}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Gemmell MA} } @conference {39201, title = {The effect of grazing time and supplementary feeding of hay on production per cow in early lactation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {26}, year = {1966}, month = {Jan}, pages = {71-85}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Hutton JB and Parker OF} } @conference {39199, title = {Effects of intra-duodenal infusions of fat on the food intake of sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {26}, year = {1966}, month = {Jan}, pages = {36-51}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Tichen DA and Reid CSW and Vlieg P} } @conference {39206, title = {Eradication of Brucellosis from the New Zealand cattle population}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {26}, year = {1966}, month = {Jan}, pages = {125-133}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Hopkirk CSM} } @conference {39207, title = {Field and experimental epidemiology of Salmonella infection in calves}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {26}, year = {1966}, month = {Jan}, pages = {134-144}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Robinson RA} } @conference {39208, title = {Field observations on incidence of Mastitis and control measures}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {26}, year = {1966}, month = {Jan}, pages = {145}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Brookbanks EO} } @conference {39204, title = {Hormonal synchronization of oestrus in Romney ewes during the breeding season}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {26}, year = {1966}, month = {Jan}, pages = {107-122}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Clarke JN and Roberts EM and Carter AH and Kirton AH} } @conference {39200, title = {The in vitro prediction of herbage digestibility}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {26}, year = {1966}, month = {Jan}, pages = {52-70}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Drew KR} } @conference {39211, title = {Internal parasites of sheep and their effects on production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {26}, year = {1966}, month = {Jan}, pages = {165-181}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Brunsdon RV} } @conference {39196, title = {Presidential Address: Research in Agriculture}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {26}, year = {1966}, month = {Jan}, pages = {1-7}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Johns AT} } @conference {39202, title = {Problems in the economic interpretation of pig feeding experiments}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {26}, year = {1966}, month = {Jan}, pages = {86-97}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Candler WV} } @conference {39198, title = {Some aspects of the behaviour of grazing sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {26}, year = {1966}, month = {Jan}, pages = {22-35}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Lancashire JA and Keogh RG} } @conference {39209, title = {Some bacteriological aspects of Mastitis diagnosis and control}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {26}, year = {1966}, month = {Jan}, pages = {146-160}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Elliott REW} } @conference {39212, title = {Some economic effects of disease}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {26}, year = {1966}, month = {Jan}, pages = {182-188}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Fielden ED} } @conference {39197, title = {Stability and productivity of pastures}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {26}, year = {1966}, month = {Jan}, pages = {8-21}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Morley FHW} } @conference {39205, title = {Symposium: Disease and Animal Production - Introduction}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {26}, year = {1966}, month = {Jan}, pages = {123-124}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Lancaster MC} } @conference {39203, title = {Variation in ovarian activity of Romney Marsh ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {26}, year = {1966}, month = {Jan}, pages = {98-106}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McDonald MF and Ch{\textquoteright}ang TS} } @conference {39193, title = {The analysis and interpretation of data on the body weight of the two-tooth ewe}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {25}, year = {1965}, month = {Jan}, pages = {164-183}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Cockrem F} } @conference {39191, title = {The cell count of milk and rapid tests for Mastitis}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {25}, year = {1965}, month = {Jan}, pages = {137-151}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Whittlestone WG and de Langen H} } @conference {39184, title = {Current developments in poultry breeding and selection}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {25}, year = {1965}, month = {Jan}, pages = {43-51}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Patchell MR} } @conference {39183, title = {The estimation of carcass composition in bacon weight pigs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {25}, year = {1965}, month = {Jan}, pages = {26-42}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Joblin ADH} } @conference {39194, title = {Extent and nature of weight losses due to pre-slaughter fasting of lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {25}, year = {1965}, month = {Jan}, pages = {184-194}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Kirton AH and Clarke JN and Carter AH and Sinclair DP} } @conference {39185, title = {Further experiments on the effect of pre-milking stimulus on dairy cow production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {25}, year = {1965}, month = {Jan}, pages = {52-64}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Phillips DSM} } @conference {39182, title = {Memorial address: William Riddet of Massey}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {25}, year = {1965}, month = {Jan}, pages = {13-25}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Campbell IL} } @conference {39190, title = {Pasture quality in terms of soluble carbohydrates and volatile fatty acid production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {25}, year = {1965}, month = {Jan}, pages = {119-136}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Kingsbury LR} } @conference {39192, title = {Practical implications of anatomical research in beef cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {25}, year = {1965}, month = {Jan}, pages = {152-163}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Butterfield RM} } @conference {39181, title = {Presidential address: Animal Production and the Society}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {25}, year = {1965}, month = {Jan}, pages = {1-12}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Stichbury JW} } @conference {39186, title = {Quantitative Studies of Digestion in the Reticulo-Rumen I. Total removal and return of digesta for quantitative sampling in studies of digestion in the reticulo-rumen of cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {25}, year = {1965}, month = {Jan}, pages = {65-84}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Reid CSW} } @conference {39187, title = {Quantitative Studies of Digestion in the Reticulo-Rumen II. The digestion of insoluble carbohydrates in the reticulo-rumen}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {25}, year = {1965}, month = {Jan}, pages = {85-95}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Bailey RW} } @conference {39188, title = {Quantitative Studies of Digestion in the Reticulo-Rumen III. Fluctuations in the numbers of rumen protozoa and their possible role in bloat}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {25}, year = {1965}, month = {Jan}, pages = {96-105}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Clarke RTJ} } @conference {39195, title = {A technique for evaluating fat lamb production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {25}, year = {1965}, month = {Jan}, pages = {195-201}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Inkster IJ and Jury KE and Muller JP} } @conference {39189, title = {Variations in ruminal pH, volatile fatty acid concentration and proportions of the individual acids}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {25}, year = {1965}, month = {Jan}, pages = {106-118}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Davey AWF} } @conference {39175, title = {Assessment of body composition in the live animal}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {24}, year = {1964}, month = {Jan}, pages = {77-89}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Kirton AH} } @conference {39176, title = {The ecology of pastoral production in Australia}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {24}, year = {1964}, month = {Jan}, pages = {90-110}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Moule GR} } @conference {39180, title = {Economic implications of increased wool production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {24}, year = {1964}, month = {Jan}, pages = {164-180}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Philpott BP} } @conference {39177, title = {Genetic problems in increasing sheep production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {24}, year = {1964}, month = {Jan}, pages = {111-128}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Rae AL} } @conference {39169, title = {Grazed Pasture Parameters: Dead herbage, net gain and utilization of pasture}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {24}, year = {1964}, month = {Jan}, pages = {17-28}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Campbell AG} } @conference {39168, title = {Presidential Address: Better Meat for a Bigger Market}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {24}, year = {1964}, month = {Jan}, pages = {1-16}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Barton RA} } @conference {39179, title = {Problems of disease and fertility in sheep production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {24}, year = {1964}, month = {Jan}, pages = {149-163}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Te Punga WA} } @conference {39172, title = {The release of plant cell contents and its relation to bloat}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {24}, year = {1964}, month = {Jan}, pages = {57-66}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Bryant AM} } @conference {39178, title = {Sheep nutrition and management}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {24}, year = {1964}, month = {Jan}, pages = {129-148}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Coop IE} } @conference {39173, title = {Sperm transport in the female rabbit}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {24}, year = {1964}, month = {Jan}, pages = {67-68}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Inkster IJ} } @conference {39171, title = {Studies on some factors influencing food intake in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {24}, year = {1964}, month = {Jan}, pages = {43-56}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Ulyatt MJ} } @conference {39174, title = {Studies on the maintenance of the corpus luteum in the ewe}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {24}, year = {1964}, month = {Jan}, pages = {69-76}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McDonald MF} } @conference {39170, title = {The voluntary intake of the lactating dairy cow and its relation to digestion}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {24}, year = {1964}, month = {Jan}, pages = {29-42}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Hutton JB and Hughes JW and Newth RP and Watanabe K} } @conference {39164, title = {Animal Research in a Tussock Environment at Tara Hills}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {23}, year = {1963}, month = {Jan}, pages = {131-143}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Scott JDJ and Ludecke TE and Lewis KHC and Diack AR} } @conference {39153, title = {Availability of selenium in forage to ruminants}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {23}, year = {1963}, month = {Jan}, pages = {13-19}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Butler GW and Peterson PJ} } @conference {39167, title = {Diet and the motility of the forestomachs of the sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {23}, year = {1963}, month = {Jan}, pages = {169-188}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Reid CSW} } @conference {39156, title = {The effect of lactation of intake in the dairy cow}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {23}, year = {1963}, month = {Jan}, pages = {39-52}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Hutton JB} } @conference {39161, title = {Genotype-pasture interaction in the fertility of Romney Marsh ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {23}, year = {1963}, month = {Jan}, pages = {100-106}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Ch{\textquoteright}ang TS} } @conference {39159, title = {The influence of rams on the onset of the breeding season in ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {23}, year = {1963}, month = {Jan}, pages = {79-87}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Edgar DG and Bilkey DA} } @conference {39166, title = {An introduction to the use of simulation in the study of grazing management problems}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {23}, year = {1963}, month = {Jan}, pages = {159-168}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Arcus PL} } @conference {39157, title = {Maintenance and lactation requirements of grazing sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {23}, year = {1963}, month = {Jan}, pages = {53-62}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Coop IE and Drew KR} } @conference {39158, title = {Methods of assessing herbage feeding value}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {23}, year = {1963}, month = {Jan}, pages = {63-78}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Minson DJ} } @conference {39155, title = {Nitrate - A factor in animal health}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {23}, year = {1963}, month = {Jan}, pages = {28-38}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Garner GB} } @conference {39152, title = {Presidential Address: The New Zealand Society of Animal Production - Its past, present and future}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {23}, year = {1963}, month = {Jan}, pages = {5-12}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Andrews ED} } @conference {39154, title = {Selenium and Ewe Fertility}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {23}, year = {1963}, month = {Jan}, pages = {20-27}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Hartley WJ} } @conference {39162, title = {Some effects of endogenous hormones on muscles and connective tissue, with special reference to the ewe}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {23}, year = {1963}, month = {Jan}, pages = {107-120}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Bassett EG} } @conference {39165, title = {Systems of pig production in Canterbury: An economic appraisal}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {23}, year = {1963}, month = {Jan}, pages = {144-158}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Longwill A} } @conference {39160, title = {The use of return interval pattern to indicate dairy herd infertility problems}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {23}, year = {1963}, month = {Jan}, pages = {88-99}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Castle OM} } @conference {39163, title = {Variations in the iodine values of fats from fatty, muscular and bone tissues of the Romney sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {23}, year = {1963}, month = {Jan}, pages = {121-130}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Barton RA and Shorland FB and Rae AL} } @conference {39139, title = {Bull sampling programmes in the artificial breeding of dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {22}, year = {1962}, month = {Jan}, pages = {54-66}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Searle SR} } @conference {39140, title = {Dairy cattle improvement overseas}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {22}, year = {1962}, month = {Jan}, pages = {67-74}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Stichbury JW} } @conference {39149, title = {Dairy herd fertility}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {22}, year = {1962}, month = {Jan}, pages = {139}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Shannon P} } @conference {39141, title = {Genetic Improvement Symposium - Discussion}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {22}, year = {1962}, month = {Jan}, pages = {75-78}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Anonymous} } @conference {39147, title = {Goitre and neonatal mortality in lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {22}, year = {1962}, month = {Jan}, pages = {123-132}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Andrews ED and Sinclair DP} } @conference {39136, title = {The Maintenance Requirements of New Zealand Dairy Cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {22}, year = {1962}, month = {Jan}, pages = {12-34}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Hutton JB} } @conference {39148, title = {The movement of ova in the genital tract of the ewe}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {22}, year = {1962}, month = {Jan}, pages = {133-138}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Edgar DG} } @conference {39142, title = {Nitrogen metabolism in the rumen}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {22}, year = {1962}, month = {Jan}, pages = {79-87}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McDonald IW} } @conference {39144, title = {Pasture carbohydrates and the ruminant}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {22}, year = {1962}, month = {Jan}, pages = {99-108}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Bailey RW} } @conference {39135, title = {Presidential Address: Research Administration}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {22}, year = {1962}, month = {Jan}, pages = {5-11}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Flux DS} } @conference {39151, title = {Production economics and problems of animal production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {22}, year = {1962}, month = {Jan}, pages = {142-158}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Candler WV} } @conference {39137, title = {Prospects in animal improvement through breeding}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {22}, year = {1962}, month = {Jan}, pages = {35-44}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Rae AL} } @conference {39145, title = {The role of protozoa in rumen fermentation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {22}, year = {1962}, month = {Jan}, pages = {109-117}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Howard BH} } @conference {39146, title = {Rumen Physiology Symposium - Discussion}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {22}, year = {1962}, month = {Jan}, pages = {118-122}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Anonymous} } @conference {39143, title = {Some aspects of rumen metabolism influencing intake and production in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {22}, year = {1962}, month = {Jan}, pages = {88-98}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Johns AT} } @conference {39138, title = {A suggested approach to the selection of domestic animals on physiological characters}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {22}, year = {1962}, month = {Jan}, pages = {45-53}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Cockrem F} } @conference {39150, title = {Symposium on Factors Affecting Fertility - Discussion}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {22}, year = {1962}, month = {Jan}, pages = {140-141}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Anonymous} } @conference {39132, title = {Biological aspects of the sulphur content of Romney wool}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {21}, year = {1961}, month = {Jan}, pages = {153-165}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Ross DA} } @conference {39128, title = {Discussion on Symposium}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {21}, year = {1961}, month = {Jan}, pages = {121-123}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Anonymous} } @conference {39125, title = {The energy requirements of sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {21}, year = {1961}, month = {Jan}, pages = {79-91}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Coop IE} } @conference {39121, title = {Factors limiting pasture production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {21}, year = {1961}, month = {Jan}, pages = {33-46}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Brougham RW} } @conference {39119, title = {Field observations of the effect of grazing management on pasture production on a soil of volcanic origin}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {21}, year = {1961}, month = {Jan}, pages = {10-17}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McKenzie SA} } @conference {39122, title = {Grazing Management}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {21}, year = {1961}, month = {Jan}, pages = {47-60}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McMeekan CP} } @conference {39124, title = {Nutritional requirements of dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {21}, year = {1961}, month = {Jan}, pages = {64-78}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Wallace LR} } @conference {39127, title = {The nutritional requirements of swine}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {21}, year = {1961}, month = {Jan}, pages = {109-120}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Smith DM} } @conference {39134, title = {Observation of some effects of glucose infusion in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {21}, year = {1961}, month = {Jan}, pages = {176-177}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Boda JM and Riley PW} } @conference {39133, title = {The pollination of red clover and lucerne in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {21}, year = {1961}, month = {Jan}, pages = {166-175}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Gurr L} } @conference {39118, title = {Presidential Address: Higher Agricultural Education}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {21}, year = {1961}, month = {Jan}, pages = {5-9}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Stewart A} } @conference {39126, title = {Relative effects of environment and liveweight upon the feed requirements of sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {21}, year = {1961}, month = {Jan}, pages = {92-108}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Lambourne LJ} } @conference {39120, title = {A theoretical basis for grazing management}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {21}, year = {1961}, month = {Jan}, pages = {18-32}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Campbell AG} } @conference {39131, title = {The use of electronic measuring techniques in agricultural research}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {21}, year = {1961}, month = {Jan}, pages = {144-152}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Phillips DSM} } @conference {39130, title = {The use of isotopes in animal and plant research}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {21}, year = {1961}, month = {Jan}, pages = {130-143}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Butler GW} } @conference {39129, title = {The use of small animals in agricultural research}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {21}, year = {1961}, month = {Jan}, pages = {124-129}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Flux DS} } @conference {39106, title = {Advances in controlled sheep breeding}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {20}, year = {1960}, month = {Jan}, pages = {42-53}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Robinson TJ} } @conference {39104, title = {The application of research findings in farm advisory work (Presidential Address)}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {20}, year = {1960}, month = {Jan}, pages = {5-12}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Gerring JC} } @conference {39109, title = {A biopsy study of growth and development of muscle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {20}, year = {1960}, month = {Jan}, pages = {58-60}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Everitt GC} } @conference {39107, title = {Brucellosis in animals and man}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {20}, year = {1960}, month = {Jan}, pages = {54-55}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Cameron HS} } @conference {39116, title = {Cattle Twins: The maternal environment and animal production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {20}, year = {1960}, month = {Jan}, pages = {95-107}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Brumby PJ} } @conference {39113, title = {Current research and practice in silage making overseas}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {20}, year = {1960}, month = {Jan}, pages = {75-81}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Lancaster RJ} } @conference {39115, title = {The effect of pre-milking stimulation on milk and butterfat production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {20}, year = {1960}, month = {Jan}, pages = {93-94}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Phillips DSM} } @conference {39105, title = {The future of agricultural research}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {20}, year = {1960}, month = {Jan}, pages = {13-41}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Dick ID} } @conference {39117, title = {An inherited blindness (Cataract) in cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {20}, year = {1960}, month = {Jan}, pages = {108}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Carter AH} } @conference {39111, title = {Nematodirosis in lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {20}, year = {1960}, month = {Jan}, pages = {63-66}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Brunsdon RV} } @conference {39110, title = {A progress report on research on face cover}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {20}, year = {1960}, month = {Jan}, pages = {61-62}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Cockrem F} } @conference {39108, title = {Selenium and animal health}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {20}, year = {1960}, month = {Jan}, pages = {56-57}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Hartley WJ} } @conference {39112, title = {Some recent results of research in rumen microbiology}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {20}, year = {1960}, month = {Jan}, pages = {67-74}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Wright DE} } @conference {39114, title = {The structure of pasture in relation to production potential}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {20}, year = {1960}, month = {Jan}, pages = {82-92}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Mitchell KJ} } @conference {39099, title = {The association of sporidesmium with facial eczema}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {19}, year = {1959}, month = {Jan}, pages = {77-82}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Percival JC} } @conference {39098, title = {The beaker test as an indicator of facial eczema toxicity}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {19}, year = {1959}, month = {Jan}, pages = {69-76}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Clare NT} } @conference {39096, title = {Biological assays for toxicity}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {19}, year = {1959}, month = {Jan}, pages = {59-63}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Worker NA} } @conference {39102, title = {The chemical composition of rapidly growing ryegrass and its relation to animal production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {19}, year = {1959}, month = {Jan}, pages = {99-110}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Butler GW} } @conference {39097, title = {Chemical extraction and fractionation of the toxin}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {19}, year = {1959}, month = {Jan}, pages = {64-68}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {White EP} } @conference {39095, title = {The collection of toxic grass and the preservation of toxicity}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {19}, year = {1959}, month = {Jan}, pages = {53-58}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Clare NT} } @conference {39088, title = {Consolidation as a factor in silage fermentation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {19}, year = {1959}, month = {Jan}, pages = {16-19}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Lancaster RJ} } @conference {39100, title = {The identification and culture of sporidesmium bakeri syd.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {19}, year = {1959}, month = {Jan}, pages = {83-90}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Thornton RH} } @conference {39092, title = {Leadership in a herd of dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {19}, year = {1959}, month = {Jan}, pages = {36-43}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Kilgour R and Scott TH} } @conference {39103, title = {Mating of Hoggets}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {19}, year = {1959}, month = {Jan}, pages = {111-119}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Lewis KHC} } @conference {39091, title = {The mechanical activity of the reticulo-rumen of cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {19}, year = {1959}, month = {Jan}, pages = {23-35}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Reid CSW and Cornwall JB} } @conference {39094, title = {The Pathology of Facial Eczema}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {19}, year = {1959}, month = {Jan}, pages = {48-52}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Dodd DC} } @conference {39090, title = {The relationship of genetic merit to between herd differences in milk production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {19}, year = {1959}, month = {Jan}, pages = {21-22}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Brumby PJ} } @conference {39087, title = {Research, extension and the farmer (Presidential Address)}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {19}, year = {1959}, month = {Jan}, pages = {5-15}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Smith DM} } @conference {39089, title = {Sources of protein for milk production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {19}, year = {1959}, month = {Jan}, pages = {20}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Synge RLM} } @conference {39101, title = {A summary of intake studies with hoggets}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {19}, year = {1959}, month = {Jan}, pages = {91-98}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Clarke EA} } @conference {39093, title = {Symposium on Facial Eczema Research - Introduction}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {19}, year = {1959}, month = {Jan}, pages = {44-47}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McMeekan CP} } @conference {39076, title = {Agricultural Advisory Services}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {18}, year = {1958}, month = {Jan}, pages = {51-60}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Cornwell J} } @conference {39072, title = {Animal factors in the Aetiology of Bloat}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {18}, year = {1958}, month = {Jan}, pages = {21-31}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Johns AT and Mangan JL and Reid CSW} } @conference {39082, title = {Assessment of Fat in Mutton and Lamb}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {18}, year = {1958}, month = {Jan}, pages = {112-125}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Barton RA and Kirton AH} } @conference {39079, title = {Cervical Mucus Arborization - Its use in assessing ovarian activity in the ewe}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {18}, year = {1958}, month = {Jan}, pages = {87-96}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McDonald MF and Raeside JI} } @conference {39077, title = {Davidson and Brydone Founders of the New Zealand Meat Export Industry}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {18}, year = {1958}, month = {Jan}, pages = {61-76}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Hewland PD} } @conference {39074, title = {The effect of stocking rate and concentrate feeding on the conversion of pasture to milk}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {18}, year = {1958}, month = {Jan}, pages = {34-42}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McMeekan CP} } @conference {39085, title = {The effect of Thyroxine on the Romney two-tooth}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {18}, year = {1958}, month = {Jan}, pages = {141-152}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Ross DA and Lewis KHC} } @conference {39071, title = {Genetics and Livestock Improvement (Presidential Address)}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {18}, year = {1958}, month = {Jan}, pages = {5-20}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Rae AL} } @conference {39078, title = {Hormones in relation to animal production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {18}, year = {1958}, month = {Jan}, pages = {77-86}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Hammond J} } @conference {39080, title = {The induction of ovulation and oestrus in ewes during anoestrus (Summary only)}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {18}, year = {1958}, month = {Jan}, pages = {97-98}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Edgar DG} } @conference {39084, title = {The influence of Thyroxine on wool growth}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {18}, year = {1958}, month = {Jan}, pages = {128-140}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Ferguson KA} } @conference {39081, title = {Recent Work on Animal Fats}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {18}, year = {1958}, month = {Jan}, pages = {99-111}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Shorland FB} } @conference {39086, title = {Responses of sheep to Thyroxine implantation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {18}, year = {1958}, month = {Jan}, pages = {153-164}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Hart DS} } @conference {39075, title = {Some effects of treading on pasture}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {18}, year = {1958}, month = {Jan}, pages = {43-50}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Edmond DB} } @conference {39073, title = {Studies in the Utilization of Winter Pasture by Dairy Cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {18}, year = {1958}, month = {Jan}, pages = {32-33}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Wallace LR} } @conference {39083, title = {Use of Monozygous Twins for Experiments Involving Changes in the Characteristics of Butterfat}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {18}, year = {1958}, month = {Jan}, pages = {126-127}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McDowall FH} } @conference {39068, title = {Blood levels of progesterone in the ewe}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {17}, year = {1957}, month = {Jan}, pages = {78-79}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Edgar DG and Ronaldson JW} } @conference {39070, title = {Border Leicester cross ewes for fat lamb production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {17}, year = {1957}, month = {Jan}, pages = {88-95}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Coop IE} } @conference {39067, title = {The breeding behaviour of two-tooth ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {17}, year = {1957}, month = {Jan}, pages = {72-77}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Inkster IJ} } @conference {39064, title = {Comparison of faecal pigments and faecal nitrogen for the estimation of feed-to-faces ratio of pasture-fed cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {17}, year = {1957}, month = {Jan}, pages = {56-62}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Kennedy WK and Lancaster RJ} } @conference {39057, title = {Concentrate Feeding of Dairy Cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {17}, year = {1957}, month = {Jan}, pages = {20-22}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Wallace LR} } @conference {39059, title = {The daily water consumption of a herd of dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {17}, year = {1957}, month = {Jan}, pages = {25-26}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Campbell IL and Munford RE} } @conference {39062, title = {Further studies on meat production per acre}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {17}, year = {1957}, month = {Jan}, pages = {41-45}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Walker DE} } @conference {39063, title = {Pasture growth rate studies in relation to grazing management}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {17}, year = {1957}, month = {Jan}, pages = {46-55}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Brougham RW} } @conference {39061, title = {Preliminary trials with whey for fattening pigs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {17}, year = {1957}, month = {Jan}, pages = {37-40}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Dunkin AC} } @conference {39056, title = {Presidential Address: The Progress and Prospects of Artificial Breeding in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {17}, year = {1957}, month = {Jan}, pages = {5-19}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {James JP} } @conference {39060, title = {Recent developments in herd improvement}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {17}, year = {1957}, month = {Jan}, pages = {27-36}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Stichbury JW} } @conference {39066, title = {Rumen Studies in Sheep - Levels of Microbial End-Products}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {17}, year = {1957}, month = {Jan}, pages = {70-71}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Williams VJ and Christian KR} } @conference {39069, title = {A study on the breeding season of Romney ewe lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {17}, year = {1957}, month = {Jan}, pages = {80-87}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Ch{\textquoteright}ang TS and Raeside JI} } @conference {39058, title = {Two experiments on the effect of short periods of underfeeding on the yield and composition of cows milk}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {17}, year = {1957}, month = {Jan}, pages = {23-24}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Patchell MR and Flux DS} } @conference {39065, title = {Variations in the digestible energy content of New Zealand sheep pastures}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {17}, year = {1957}, month = {Jan}, pages = {63-69}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Lambourne LJ} } @conference {39055, title = {Antipyrine for In Vivo Body-Fat Estimations in pasture-Grazing Animals}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {16}, year = {1956}, month = {Jan}, pages = {141-142}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {White RR and McDonald MA} } @conference {39040, title = {A Comparison of Hogget Thrift on Perennial Ryegrass and White Clover}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {16}, year = {1956}, month = {Jan}, pages = {23-30}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Sinclair DP and Clarke EA and Filmer DB} } @conference {39047, title = {Cornell Research on Methods of Selecting Dairy Sires}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {16}, year = {1956}, month = {Jan}, pages = {69-76}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Henderson CR} } @conference {39050, title = {The economic and management consequences of early weaning pigs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {16}, year = {1956}, month = {Jan}, pages = {95-100}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Smith DM} } @conference {39041, title = {The effect of high and low plane rearing of hoggets on lifetime productivity}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {16}, year = {1956}, month = {Jan}, pages = {31-38}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Coop IE} } @conference {39044, title = {Face Cover in Corriedale Sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {16}, year = {1956}, month = {Jan}, pages = {55-58}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Coop IE} } @conference {39045, title = {Face Cover in Romney Sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {16}, year = {1956}, month = {Jan}, pages = {59-65}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Cockrem FR and Barton RA and Rae AL} } @conference {39039, title = {Hogget Ill-thrift}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {16}, year = {1956}, month = {Jan}, pages = {22}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Clarke EA and Filmer DB} } @conference {39038, title = {Memorial Address: W.J. Croucher, Father to the Pig Industry}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {16}, year = {1956}, month = {Jan}, pages = {13-21}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McMeekan CP} } @conference {39053, title = {Methods of Bloat Control}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {16}, year = {1956}, month = {Jan}, pages = {122-129}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Reid CSW} } @conference {39049, title = {The Milking Characteristics of Identical Twin Cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {16}, year = {1956}, month = {Jan}, pages = {89-94}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Brumby P} } @conference {39043, title = {New Zealand Climatic Production Potentials of Pasture Plants}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {16}, year = {1956}, month = {Jan}, pages = {48-54}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Mitchell KJ} } @conference {39037, title = {Presidential Address}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {16}, year = {1956}, month = {Jan}, pages = {5-12}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Durrant T} } @conference {39046, title = {The relationship between face cover and reproductive efficiency in Romney Ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {16}, year = {1956}, month = {Jan}, pages = {66-68}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Inkster IJ} } @conference {39042, title = {Sheep Management on Improved Hill Pastures}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {16}, year = {1956}, month = {Jan}, pages = {39-47}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Suckling FET} } @conference {39048, title = {Some Aspects of Dairy Sire Selection}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {16}, year = {1956}, month = {Jan}, pages = {77-88}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Carter AH} } @conference {39052, title = {Some economic aspect of New Zealand{\textquoteright}s Livestock Industry}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {16}, year = {1956}, month = {Jan}, pages = {115-121}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Paton WN} } @conference {39051, title = {Sources of Loss in the Unfertilised and Fertilised Sheep{\textquoteright}s Ova}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {16}, year = {1956}, month = {Jan}, pages = {101-114}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Hart DS} } @conference {39054, title = {Twenty-Five Years of Mendelian Sheep-Breeding}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {16}, year = {1956}, month = {Jan}, pages = {130-140}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Dry FW} } @conference {39034, title = {The Bacteriology of Lamb Mortality}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {15}, year = {1955}, month = {Jan}, pages = {120-125}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Hartley WJ and Boyes BW} } @conference {39026, title = {The Chemical Control of Ecto-Parasites of Sheep and Cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {15}, year = {1955}, month = {Jan}, pages = {66-73}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Allan WS} } @conference {39020, title = {An Economic Survey of the New Zealand Sheep Industry}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {15}, year = {1955}, month = {Jan}, pages = {24-31}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Keen WL} } @conference {39031, title = {The Effect of Some Endocrine Factors on Mammary Gland Growth and Lactation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {15}, year = {1955}, month = {Jan}, pages = {95-102}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Flux DS} } @conference {39036, title = {Factors Affecting the Non-Fatty Solids in Milk, with Particular Reference to the New Zealand Town Milk Industry}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {15}, year = {1955}, month = {Jan}, pages = {132-139}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Campbell IL and Flux DS and Patchell MR} } @conference {39021, title = {The Fleece as a Factor in Sheep Adaptation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {15}, year = {1955}, month = {Jan}, pages = {32-35}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Henderson AE} } @conference {39027, title = {The Intakes of Grass and Silage by Dairy Cows During the Summer}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {15}, year = {1955}, month = {Jan}, pages = {74-80}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Percival JC} } @conference {39024, title = {Meat Production per Acre}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {15}, year = {1955}, month = {Jan}, pages = {51-56}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Walker DE} } @conference {39019, title = {Memorial Address: James Little and His Corriedale Sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {15}, year = {1955}, month = {Jan}, pages = {17-23}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Stevens PG} } @conference {39030, title = {Molybdenum and Animal Health in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {15}, year = {1955}, month = {Jan}, pages = {93-94}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Cunningham IJ} } @conference {39033, title = {Neonatal Lamb Mortality in the Gisborne Area}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {15}, year = {1955}, month = {Jan}, pages = {104-119}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McFarlane D} } @conference {39025, title = {The Photoperiodic and Hormone Response of Wool Growth in Sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {15}, year = {1955}, month = {Jan}, pages = {57-65}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Hart DS} } @conference {39018, title = {Presidential Address: Some Animal Production Problems of the South Island}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {15}, year = {1955}, month = {Jan}, pages = {5-16}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Coop IE} } @conference {39022, title = {Recent Developments in the Field Study of Sheep Nutrition}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {15}, year = {1955}, month = {Jan}, pages = {36-47}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Lambourne LJ} } @conference {39029, title = {The Role of Molybdenum in Plant Nutrition}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {15}, year = {1955}, month = {Jan}, pages = {86-92}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Davies EB and Grigg JL} } @conference {39023, title = {Role of Rumen Microflora in Ruminant Metabolism}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {15}, year = {1955}, month = {Jan}, pages = {48-50}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Gall LS} } @conference {39032, title = {Some Aspects of the Inheritance of Fertility in Sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {15}, year = {1955}, month = {Jan}, pages = {103}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Rae AL and Ch{\textquoteright}ang TS} } @conference {39028, title = {Studies of Molybdenum in the Soil}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {15}, year = {1955}, month = {Jan}, pages = {81-85}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Healy WB} } @conference {39035, title = {Techniques and Results of Low Temperature Bull Semen Storage}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {15}, year = {1955}, month = {Jan}, pages = {126-131}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {James JP and Fyvie AA} } @conference {39014, title = {Break versus Paddock Grazing of Dairy Cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {14}, year = {1954}, month = {Jan}, pages = {111-117}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McMeekan CP and Hancock J} } @conference {39002, title = {The Future of Animal Production in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {14}, year = {1954}, month = {Jan}, pages = {14-26}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Hamilton WM} } @conference {39007, title = {The Future of Animal Research}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {14}, year = {1954}, month = {Jan}, pages = {60-68}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McMeekan CP} } @conference {39003, title = {The Future of Dairying in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {14}, year = {1954}, month = {Jan}, pages = {27-31}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Perry WN} } @conference {39006, title = {The Future of Grassland Research in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {14}, year = {1954}, month = {Jan}, pages = {52-59}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Melville J} } @conference {39005, title = {The Future of Land Development in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {14}, year = {1954}, month = {Jan}, pages = {45-51}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Greig DM} } @conference {39012, title = {Levels of Inbreeding in New Zealand Pedigree Jersey Cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {14}, year = {1954}, month = {Jan}, pages = {96-102}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Stewart A} } @conference {39008, title = {New Zealand{\textquoteright}s Place in the Meat Export Trade}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {14}, year = {1954}, month = {Jan}, pages = {69-76}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Bevin RH} } @conference {39011, title = {Observations on Helminth Parasites and Hogget Unthriftiness in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {14}, year = {1954}, month = {Jan}, pages = {91-95}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Clarke EA and Filmer DB} } @conference {39013, title = {The Physiology of Milk Ejection and its Role in Dairy Production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {14}, year = {1954}, month = {Jan}, pages = {103-110}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Brumby PJ} } @conference {39001, title = {Presidential Address: The Veterinary Surgeon and Animal Production in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {14}, year = {1954}, month = {Jan}, pages = {5-13}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McFarlane D} } @conference {39009, title = {The Role of Carotene in Ovine Rickets}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {14}, year = {1954}, month = {Jan}, pages = {77-83}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Grant AB} } @conference {39004, title = {The Role of the Meat and Wool Industries in the Future of New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {14}, year = {1954}, month = {Jan}, pages = {32-44}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Reeves S} } @conference {39015, title = {Sampling Systems for Dependent Data}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {14}, year = {1954}, month = {Jan}, pages = {118-120}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Williams RM} } @conference {39010, title = {Some Observations on the Effect of Drenching Young Sheep with Phenothiazine}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {14}, year = {1954}, month = {Jan}, pages = {84-90}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Whitten LK} } @conference {39017, title = {Studies in the Pelvic Region of the Ewe during Pregnancy and Parturition}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {14}, year = {1954}, month = {Jan}, pages = {123-125}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Bassett EG and Phillips DSM} } @conference {39016, title = {The Value of Identical Twins in Research}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {14}, year = {1954}, month = {Jan}, pages = {121-122}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Carter AH} } @conference {38998, title = {Environmental Factors Affecting Wool Growth}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {13}, year = {1953}, month = {Jan}, pages = {113-120}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Coop IE and Hart DS} } @conference {38989, title = {The Extension Needs of the Farmer}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {13}, year = {1953}, month = {Jan}, pages = {50-55}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Wood AG} } @conference {38988, title = {The Extension Worker and his Work}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {13}, year = {1953}, month = {Jan}, pages = {41-49}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Tyrer TG} } @conference {38986, title = {A Farmer Looks at Agricultural Education}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {13}, year = {1953}, month = {Jan}, pages = {28-33}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Durrant T} } @conference {39000, title = {Grazing Behaviour in Relation to Bloat}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {13}, year = {1953}, month = {Jan}, pages = {127}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Hancock JJ} } @conference {38995, title = {Level of Superphosphate Topdressing and Butterfat Production per Acre}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {13}, year = {1953}, month = {Jan}, pages = {97-105}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Ward AH} } @conference {38990, title = {Memorial Address: James Glenny Wilson, of Bulls}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {13}, year = {1953}, month = {Jan}, pages = {56-64}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Wild LJ} } @conference {38997, title = {Observations on Effects of Rabbit Grazing on Pasture}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {13}, year = {1953}, month = {Jan}, pages = {112}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Bull PC and Harris GS and Moore LB and Wodzicki K} } @conference {38993, title = {Pasture Establishment}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {13}, year = {1953}, month = {Jan}, pages = {82-87}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Sears PD} } @conference {38991, title = {Pasture Quality and Animal production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {13}, year = {1953}, month = {Jan}, pages = {65-73}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Melville J} } @conference {38992, title = {The Pattern of Growth of Individual Pasture Plants}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {13}, year = {1953}, month = {Jan}, pages = {74-81}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Mitchell KJ} } @conference {38983, title = {Presidential Address: The Basic Efficiency of Animal Production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {13}, year = {1953}, month = {Jan}, pages = {5-16}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Wallace LR} } @conference {38996, title = {Ruminant Metabolism}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {13}, year = {1953}, month = {Jan}, pages = {106-111}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Johns AT} } @conference {38985, title = {Secondary School Agricultural Education}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {13}, year = {1953}, month = {Jan}, pages = {24-27}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Wild GV} } @conference {38999, title = {Some Recent Advances in Facial Eczema Research}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {13}, year = {1953}, month = {Jan}, pages = {121-126}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Perrin DD and White EP and Clare NT} } @conference {38994, title = {Spray Irrigation on Grasslands}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {13}, year = {1953}, month = {Jan}, pages = {88-96}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Noble PF} } @conference {38987, title = {State Agricultural Extension Services}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {13}, year = {1953}, month = {Jan}, pages = {34-40}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Smallfield PW} } @conference {38984, title = {University Agricultural Education}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {13}, year = {1953}, month = {Jan}, pages = {17-23}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Peren GS} } @conference {38979, title = {An Approach to the Application of Field Techniques in Wildlife Research}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {12}, year = {1952}, month = {Jan}, pages = {89-93}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Riney T} } @conference {38975, title = {Augmentation of Fertility in Sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {12}, year = {1952}, month = {Jan}, pages = {61-66}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Wallace LR} } @conference {38973, title = {A Comparison of Various Selection Plans in Sheep Breeding}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {12}, year = {1952}, month = {Jan}, pages = {58-59}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Rae AL} } @conference {38969, title = {Current Genetic Thought and Dairy Cattle Breeding}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {12}, year = {1952}, month = {Jan}, pages = {16-31}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Hancock J} } @conference {38980, title = {An Endocrine Approach to the Study of the Inheritance of Milk Secretion}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {12}, year = {1952}, month = {Jan}, pages = {94-101}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Turner CW} } @conference {38970, title = {The Expansion and Structure of the New Zealand Pedigree Jersey Breed}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {12}, year = {1952}, month = {Jan}, pages = {32-39}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Stewart A} } @conference {38972, title = {The Future of Herd Improvement in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {12}, year = {1952}, month = {Jan}, pages = {49-57}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Ward AH} } @conference {38968, title = {Memorial Address: John Anderson Gilruth}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {12}, year = {1952}, month = {Jan}, pages = {10-15}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Hopkirk CSM} } @conference {38981, title = {Milk Production in the Sow}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {12}, year = {1952}, month = {Jan}, pages = {102-114}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Smith DM} } @conference {38982, title = {Milk Production of the Ewe}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {12}, year = {1952}, month = {Jan}, pages = {115-120}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Barnicoat CR} } @conference {38976, title = {Observations on Non-Nutritional Factors Affecting Fertility in Sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {12}, year = {1952}, month = {Jan}, pages = {67-75}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Hart DS and Stevens PG} } @conference {38967, title = {Presidential Address}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {12}, year = {1952}, month = {Jan}, pages = {5-9}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McGuinness S} } @conference {38971, title = {Selection Through the Herd Sire}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {12}, year = {1952}, month = {Jan}, pages = {40-48}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Castle OM} } @conference {38974, title = {Some Recently Discovered Aspects of Ewe Abortion and Ram Sterility in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {12}, year = {1952}, month = {Jan}, pages = {60}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McFarlane D and Jebson JL and McClure TJ and Hartley WJ and Salisbury RM} } @conference {38977, title = {A Study in Dairy Farming Trends in the Waipa County, 1941-1950}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {12}, year = {1952}, month = {Jan}, pages = {76-82}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Hutton JB and Wright M} } @conference {38978, title = {The Toxicity of North African Phosphate and Superphosphate to Milking Cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {12}, year = {1952}, month = {Jan}, pages = {83-88}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Swan JB and McIntosh IG} } @conference {38959, title = {Age Distribution in N.Z. Pedigree Cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {11}, year = {1951}, month = {Jan}, pages = {79-86}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Stewart A} } @conference {38960, title = {The Effect of Management on the Grazing Behaviour of Calves}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {11}, year = {1951}, month = {Jan}, pages = {87-88}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McArthur ATG} } @conference {38961, title = {Factors Affecting the Efficiency of Food Conversion by Pigs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {11}, year = {1951}, month = {Jan}, pages = {89-99}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Smith DM} } @conference {38965, title = {Growth Rates of Early and Late Weaned Single and Identical Twin Calves}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {11}, year = {1951}, month = {Jan}, pages = {107-110}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Percival JC} } @conference {38964, title = {The Importance of Genetic Correlations in Selection}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {11}, year = {1951}, month = {Jan}, pages = {104-106}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Rae AL} } @conference {38958, title = {Infertility in Rams}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {11}, year = {1951}, month = {Jan}, pages = {62-78}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Webster WM} } @conference {38963, title = {Investigation on the Excretion of Sex Hormones by Sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {11}, year = {1951}, month = {Jan}, pages = {102-103}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Bassett EG and Sewell OK and White EP} } @conference {38954, title = {The limit set to Tropical Dairy Production by Nutritional Factors}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {11}, year = {1951}, month = {Jan}, pages = {23-37}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Payne WJA and Laing WI} } @conference {38966, title = {Memorial Address - George Henry Holford}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {11}, year = {1951}, month = {Jan}, pages = {111-119}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Ranstead JM} } @conference {38956, title = {A Plan of Pig Improvement Applicable to N.Z. Conditions}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {11}, year = {1951}, month = {Jan}, pages = {48-56}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Longwill A} } @conference {38962, title = {The Practice of Flushing Ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {11}, year = {1951}, month = {Jan}, pages = {100-101}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Wallace LR} } @conference {38952, title = {Presidential Address: Some Aspects of Hill Country Sheep Improvement}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {11}, year = {1951}, month = {Jan}, pages = {5-17}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Clarke EA} } @conference {38953, title = {Some Variations in the Fleece of Romney Marsh Stud Ewes in Relation to Season and Breeding Behaviour}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {11}, year = {1951}, month = {Jan}, pages = {18-22}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Stevens PG and Wright GM} } @conference {38955, title = {To Call to Produce More Live-Stock}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {11}, year = {1951}, month = {Jan}, pages = {38-47}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Levy EB} } @conference {38957, title = {Veterinary Diagnostic Services and Primary Production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {11}, year = {1951}, month = {Jan}, pages = {57-61}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McFarlane D} } @conference {38938, title = {A Comparison of Three Rations for Dairy Cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {10}, year = {1950}, month = {Jan}, pages = {26-31}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Flux DS and Patchell MR} } @conference {38948, title = {The Effect of Level of Nutrition on the Sexual Capacity of Dairy Bulls}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {10}, year = {1950}, month = {Jan}, pages = {84-88}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {James JP} } @conference {38951, title = {The Epidemiology of Nematode Parasitism in Sheep with Particular Reference to Manawatu District}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {10}, year = {1950}, month = {Jan}, pages = {106-114}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Tetley JH} } @conference {38943, title = {The Estimation of Digestibility}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {10}, year = {1950}, month = {Jan}, pages = {45-48}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Lancaster RJ} } @conference {38940, title = {Experiments in Dairy Husbandry with Particular Reference to Yield of Fat}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {10}, year = {1950}, month = {Jan}, pages = {36-40}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Armstrong PJ} } @conference {38937, title = {The Influence of Level of Nutrition During Pregnancy and Lactation on Lamb and Wool Production of Grazing Sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {10}, year = {1950}, month = {Jan}, pages = {20-25}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Coop IE} } @conference {38950, title = {Lethal and Other Inherited Factors Causing Abnormalities in New Zealand Stock}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {10}, year = {1950}, month = {Jan}, pages = {91-105}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Hancock J} } @conference {38942, title = {The Measurement of Faeces Output}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {10}, year = {1950}, month = {Jan}, pages = {43-44}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Coup MR} } @conference {38941, title = {The Measurement of Feed Consumption of Individual Animals - Introduction}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {10}, year = {1950}, month = {Jan}, pages = {41-42}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Wallace LR} } @conference {38936, title = {Memorial Address: The Matthews of Wairongamai}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {10}, year = {1950}, month = {Jan}, pages = {11-19}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Morton AC} } @conference {38944, title = {Method of Measurement of Feed Consumption}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {10}, year = {1950}, month = {Jan}, pages = {49-56}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Percival JC} } @conference {38949, title = {Milk Production of the Sow}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {10}, year = {1950}, month = {Jan}, pages = {89-90}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Smith DM} } @conference {38935, title = {Presidential Address: The Progress of Endocrinology with Special Reference to Animal Production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {10}, year = {1950}, month = {Jan}, pages = {3-10}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Campbell IL} } @conference {38947, title = {Some Factors Influencing Milk Ejection in Mechanical Milking}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {10}, year = {1950}, month = {Jan}, pages = {81-83}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Phillips DSM} } @conference {38945, title = {Some Observation on the Use of the Movable Enclosure Method of Estimation of Pasture Consumption by Grazing Animals}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {10}, year = {1950}, month = {Jan}, pages = {57-66}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Sears PD} } @conference {38946, title = {Some Recent Experiments on the Problem of Milk Ejection}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {10}, year = {1950}, month = {Jan}, pages = {67-80}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Whittlestone WG} } @conference {38939, title = {The Use of Inbreeding in Animal Improvement}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {10}, year = {1950}, month = {Jan}, pages = {32-35}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Wright GM} } @conference {38932, title = {Beef Production \& Marketing in Relation to the Overall Objective of Increased Meat Supply}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {9}, year = {1949}, month = {Jan}, pages = {130-140}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Rowlands A} } @conference {38924, title = {Can the Hill Country Supply the Store Stock Necessary for Increased Fat Lamb Production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {9}, year = {1949}, month = {Jan}, pages = {51-59}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Bull SF} } @conference {38922, title = {Efficiency of Production of New Zealand Dairy Cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {9}, year = {1949}, month = {Jan}, pages = {32-41}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Mitchell KJ} } @conference {38930, title = {Fat Lamb Crosses in Canterbury}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {9}, year = {1949}, month = {Jan}, pages = {112-121}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Coop IE and Clark VR} } @conference {38923, title = {Grass Rationing in Relation to Production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {9}, year = {1949}, month = {Jan}, pages = {42-50}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Woodyear-Smith H} } @conference {38926, title = {Influence of Sire on Fat Lamb Quality}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {9}, year = {1949}, month = {Jan}, pages = {66-84}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Barton RA and Phillips TO and Clarke EA} } @conference {38925, title = {The Influence of the Type of Ewe upon the Type of Fat Lamb Carcass}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {9}, year = {1949}, month = {Jan}, pages = {60-65}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Walker DE and McMeekan CP} } @conference {38928, title = {Lamb Fattening on Pastures and Crops in the Gisborne District}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {9}, year = {1949}, month = {Jan}, pages = {97-106}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Simpson JEV} } @conference {38920, title = {Memorial Address: Bernard Cracroft Aston, First New Zealand Official Agricultural Chemist}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {9}, year = {1949}, month = {Jan}, pages = {10-23}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Grimmett RER} } @conference {38934, title = {Milk-Fever of Ewes in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {9}, year = {1949}, month = {Jan}, pages = {153-163}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Leslie A} } @conference {38929, title = {North Island Fat Lamb Crosses}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {9}, year = {1949}, month = {Jan}, pages = {107-111}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Walker DE} } @conference {38927, title = {Observations of Lambing Behaviour in Ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {9}, year = {1949}, month = {Jan}, pages = {85-96}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Wallace LR} } @conference {38919, title = {Presidential Address}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {9}, year = {1949}, month = {Jan}, pages = {3-9}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Campbell IL} } @conference {38921, title = {Problems of Increased Production in the Meat Industry}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {9}, year = {1949}, month = {Jan}, pages = {24-31}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McGuinness S} } @conference {38931, title = {Shearing Ewes Before Lambing}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {9}, year = {1949}, month = {Jan}, pages = {122-129}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Coop IE and Drake JH} } @conference {38933, title = {Some Observations on How the Veterinary Profession can Help Meat Production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {9}, year = {1949}, month = {Jan}, pages = {141-152}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Crawford R} } @conference {38906, title = {The Fight for Food}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {8}, year = {1948}, month = {Jan}, pages = {27-36}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Fawcett EJ} } @conference {38905, title = {Grigg of Longbeach}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {8}, year = {1948}, month = {Jan}, pages = {14-26}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Stevens PG} } @conference {38908, title = {The influence of rabbits on farm production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {8}, year = {1948}, month = {Jan}, pages = {48-53}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Wodzicki KA} } @conference {38907, title = {Land Utilisation and Settlement}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {8}, year = {1948}, month = {Jan}, pages = {37-47}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Greig D} } @conference {38918, title = {The Potential uses of Penicillin in the Treatment of Bovine Mastitis}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {8}, year = {1948}, month = {Jan}, pages = {121-130}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Roach RW} } @conference {38904, title = {Presidential Address: The Changing Face of Farming}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {8}, year = {1948}, month = {Jan}, pages = {3-13}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Ward AH} } @conference {38914, title = {Progeny Testing in Sheep - The inheritance of birth weight, growth rate and cannon bone length}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {8}, year = {1948}, month = {Jan}, pages = {86-96}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McLean JW} } @conference {38911, title = {The relationship between level of nutrition during the dry period and subsequent performance of dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {8}, year = {1948}, month = {Jan}, pages = {61-63}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Campbell IL and Flux DS} } @conference {38915, title = {Some Aspects of Progeny Testing in Sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {8}, year = {1948}, month = {Jan}, pages = {97-108}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Rae AL} } @conference {38909, title = {Some Aspects of Rabbit Control}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {8}, year = {1948}, month = {Jan}, pages = {54-59}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McIntosh IG} } @conference {38917, title = {Some Farming Trends in Whangarei County, 1940 to 1946-47}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {8}, year = {1948}, month = {Jan}, pages = {111-120}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Mitchell KJ} } @conference {38916, title = {Some Observations on the Nature of the Milk Let Down Mechanism in the Cow}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {8}, year = {1948}, month = {Jan}, pages = {109-110}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Whittlestone WG} } @conference {38913, title = {Special Purpose Pastures in Intensive Grassland Farming}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {8}, year = {1948}, month = {Jan}, pages = {72-85}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Levy EB and Sears PD} } @conference {38912, title = {Winter Milk Production from an all-grass dairy farm}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {8}, year = {1948}, month = {Jan}, pages = {64-71}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Long WS} } @conference {38901, title = {The effect of soil type on productivity in the Whangarei County}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {7}, year = {1947}, month = {Jan}, pages = {137-145}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Hamilton WM} } @conference {38897, title = {Extension Services and the Farmer}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {7}, year = {1947}, month = {Jan}, pages = {103-114}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Burnard CW} } @conference {38895, title = {Fertiliser, Pasture Considerations and Management in Relation to Fat Lamb Production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {7}, year = {1947}, month = {Jan}, pages = {75-94}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Clarke EA} } @conference {38896, title = {The Future of Fertilisers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {7}, year = {1947}, month = {Jan}, pages = {95-102}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Andrews JC} } @conference {38902, title = {The grazing behaviour of dairy cows in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {7}, year = {1947}, month = {Jan}, pages = {145-146}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Hancock JJ and Wallace NM} } @conference {38894, title = {Hill Country Problems}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {7}, year = {1947}, month = {Jan}, pages = {66-75}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Smallfield PW} } @conference {38898, title = {The influence of plane of nutrition upon the reproductive efficiency of animals}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {7}, year = {1947}, month = {Jan}, pages = {114-125}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Wallace L} } @conference {38903, title = {Influence of Season on Human Fertility}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {7}, year = {1947}, month = {Jan}, pages = {147-156}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Wodzicki KA and Hamilton WM} } @conference {38891, title = {Labour in Relation to Grasslands Dairying}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {7}, year = {1947}, month = {Jan}, pages = {42-48}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Candy RA} } @conference {38888, title = {Memorial Address - Alfred Hyde Cockayne}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {7}, year = {1947}, month = {Jan}, pages = {8-13}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Levy EB} } @conference {38899, title = {Nutritive Status of New Zealand Pastures}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {7}, year = {1947}, month = {Jan}, pages = {125-129}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Lancaster RJ} } @conference {38900, title = {Parasitism in Relation to Pasture Farming}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {7}, year = {1947}, month = {Jan}, pages = {129-136}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Whitten LK} } @conference {38889, title = {Pasture and Animal Production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {7}, year = {1947}, month = {Jan}, pages = {13-27}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McMeekan CP} } @conference {38887, title = {Presidential Address: The Expanding Science of Nutrition}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {7}, year = {1947}, month = {Jan}, pages = {1-8}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Cunningham IJ} } @conference {38893, title = {Sheep Management Problems of Poverty Bay}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {7}, year = {1947}, month = {Jan}, pages = {55-66}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McGuinness S} } @conference {38890, title = {Some Aspects of Pasture Growth and Utilisation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {7}, year = {1947}, month = {Jan}, pages = {27-42}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Sears PD} } @conference {38892, title = {Some Hazards of Grazing in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {7}, year = {1947}, month = {Jan}, pages = {49-55}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Filmer JF} } @conference {38884, title = {The accuracy of various methods of estimating a dairy cow{\textquoteright}s production of milk and butterfat}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {6}, year = {1946}, month = {Jan}, pages = {99-104}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Campbell IL} } @conference {38883, title = {Breeding N-Type Sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {6}, year = {1946}, month = {Jan}, pages = {95-99}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Dry FW} } @conference {38874, title = {Breeding of Dairy Cattle in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {6}, year = {1946}, month = {Jan}, pages = {22-32}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Stewart A} } @conference {38876, title = {Breeding of Pigs in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {6}, year = {1946}, month = {Jan}, pages = {49-54}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Smith DM} } @conference {38875, title = {Breeding of Sheep in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {6}, year = {1946}, month = {Jan}, pages = {33-48}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Stevens PG} } @conference {38882, title = {Congenital Photo-Sensitivity in Southdown Sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {6}, year = {1946}, month = {Jan}, pages = {90-95}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Hancock JJ and Bassett EG} } @conference {38873, title = {Ernest Short of Parorangi}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {6}, year = {1946}, month = {Jan}, pages = {12-21}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McMeekan CP} } @conference {38880, title = {The Influence of Heterosis in the Progeny Test}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {6}, year = {1946}, month = {Jan}, pages = {73-80}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Matson J} } @conference {38877, title = {Inheritable Cellular Antigens in Cattle Blood}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {6}, year = {1946}, month = {Jan}, pages = {54-58}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Buddle MB} } @conference {38879, title = {The inheritance of {\textquoteright}Parrot-Beak{\textquoteright} in New Zealand milking shorthorns}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {6}, year = {1946}, month = {Jan}, pages = {71-73}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Ranstead JM} } @conference {38872, title = {Presidential Address: The Group Herd Testing Movement}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {6}, year = {1946}, month = {Jan}, pages = {1-11}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Hume CM} } @conference {38878, title = {The Relationship of Artificial Insemination to Future Dairy Cattle Breeding}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {6}, year = {1946}, month = {Jan}, pages = {59-71}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {James JP} } @conference {38881, title = {Some notes on Inheritance of Productivity in Sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {6}, year = {1946}, month = {Jan}, pages = {80-90}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McMahon PR} } @conference {38885, title = {The stimulation of milk secretion in dairy cattle with Diethylstilbestrol and Thyroprotein}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {6}, year = {1946}, month = {Jan}, pages = {104-110}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Hollard MG and Campbell IL} } @conference {38886, title = {The value of separated milk and pasture as a food for dairy calves}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {6}, year = {1946}, month = {Jan}, pages = {110-113}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Cook MK} } @conference {38862, title = {Advisory functions of the field veterinary officer}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {5}, year = {1945}, month = {Jan}, pages = {33-40}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McIlwaine JE} } @conference {38870, title = {Control by vaccination of contagious abortion in dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {5}, year = {1945}, month = {Jan}, pages = {79-83}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Buddle MB} } @conference {38868, title = {Copper deficiencies and dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {5}, year = {1945}, month = {Jan}, pages = {68-71}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Cunningham IJ} } @conference {38859, title = {The economic importance of disease losses in dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {5}, year = {1945}, month = {Jan}, pages = {10-21}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Ward AH} } @conference {38861, title = {The economic importance of disease losses in pigs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {5}, year = {1945}, month = {Jan}, pages = {28-32}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Peirson R} } @conference {38860, title = {The economic importance of disease losses in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {5}, year = {1945}, month = {Jan}, pages = {21-27}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Marshall D} } @conference {38871, title = {The nutritive status of Pampas Grass}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {5}, year = {1945}, month = {Jan}, pages = {84-88}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Coup MR and Dunlop AA} } @conference {38865, title = {Plants toxic to stock in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {5}, year = {1945}, month = {Jan}, pages = {52-57}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Connor HE} } @conference {38866, title = {Poison hazards to stock}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {5}, year = {1945}, month = {Jan}, pages = {58-64}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McIntosh IG} } @conference {38858, title = {Presidential Address: Animal Research in NZ}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {5}, year = {1945}, month = {Jan}, pages = {1-9}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Filmer JF} } @conference {38867, title = {Rickets in sheep in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {5}, year = {1945}, month = {Jan}, pages = {64-68}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Fitch L} } @conference {38863, title = {The role of quarantine in prevention and control of animal disease}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {5}, year = {1945}, month = {Jan}, pages = {40-49}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Barry WC} } @conference {38864, title = {The role of the veterinary practitioner in prevention and control of animal disease}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {5}, year = {1945}, month = {Jan}, pages = {49-52}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Leslie A} } @conference {38869, title = {Vaccination as a method of control of stock diseases in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {5}, year = {1945}, month = {Jan}, pages = {72-78}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Hopkirk CSM} } @conference {38848, title = {The animal in relation to food production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {4}, year = {1944}, month = {Jan}, pages = {23-30}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Filmer JF} } @conference {38856, title = {Artificial stimulation of milk secretion in dry non-pregnant dairy cattle with diethylstilbestrol}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {4}, year = {1944}, month = {Jan}, pages = {78-83}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Campbell IL} } @conference {38855, title = {The cattle pituitary gland in relation to ovarian dysfunction}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {4}, year = {1944}, month = {Jan}, pages = {74-78}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Bassett EG} } @conference {38849, title = {Economic considerations affecting increased production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {4}, year = {1944}, month = {Jan}, pages = {30-38}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Taylor NH} } @conference {38854, title = {Experiments in poultry breeding}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {4}, year = {1944}, month = {Jan}, pages = {72-74}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Nielsen EP} } @conference {38845, title = {Food and Agriculture}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {4}, year = {1944}, month = {Jan}, pages = {1-8}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Fawcett EJ} } @conference {38850, title = {General Discussion on Papers Presented on the First Day}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {4}, year = {1944}, month = {Jan}, pages = {38-49}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Anonymous} } @conference {38853, title = {The influence of sex upon carcass quality and efficiency of food utilisation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {4}, year = {1944}, month = {Jan}, pages = {64-72}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Wallace LR} } @conference {38857, title = {A new technique for the study of milk ejection in the dairy cow}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {4}, year = {1944}, month = {Jan}, pages = {83-97}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Whittlestone WG} } @conference {38847, title = {Plants and Food}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {4}, year = {1944}, month = {Jan}, pages = {16-23}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Callaghan FR} } @conference {38846, title = {Soils and Food Production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {4}, year = {1944}, month = {Jan}, pages = {8-16}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Taylor NH} } @conference {38852, title = {Some further observations on fat lamb production in Canterbury}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {4}, year = {1944}, month = {Jan}, pages = {55-64}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Walker DE} } @conference {38851, title = {Summer Fattening of Lambs in Canterbury}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {4}, year = {1944}, month = {Jan}, pages = {49-55}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Ewer TK} } @conference {38840, title = {Calf nutrition and the importance of nutrition in the post weaning stages}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {3}, year = {1943}, month = {Jan}, pages = {58-65}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Ballinger CE} } @conference {38835, title = {The control of contagious abortion}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {3}, year = {1943}, month = {Jan}, pages = {32-37}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Buddle MB} } @conference {38832, title = {Factors affecting the rate of herd improvement in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {3}, year = {1943}, month = {Jan}, pages = {11-20}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Hamilton WM} } @conference {38834, title = {Female Sterility}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {3}, year = {1943}, month = {Jan}, pages = {26-31}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Webster WM} } @conference {38838, title = {The influence of nutrition on the composition of the milk of dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {3}, year = {1943}, month = {Jan}, pages = {52-55}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McDowall FH} } @conference {38842, title = {The inheritance of multi-factorial characters in the sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {3}, year = {1943}, month = {Jan}, pages = {70-81}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McMahon PR} } @conference {38844, title = {Lactation Curves}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {3}, year = {1943}, month = {Jan}, pages = {86-95}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Riddet W and Campbell IL} } @conference {38841, title = {Occurrence of congenital porphyria with bone pigmentation in pigs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {3}, year = {1943}, month = {Jan}, pages = {66-70}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Clare NT} } @conference {38839, title = {Preliminary Observations on the Milk Supply of the Ewe}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {3}, year = {1943}, month = {Jan}, pages = {56-58}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Barnicoat CR} } @conference {38831, title = {Presidential Address - The control of adaptability phenomena}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {3}, year = {1943}, month = {Jan}, pages = {1-10}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McMeekan CP} } @conference {38843, title = {Purposeful Breeding in Plant Improvement}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {3}, year = {1943}, month = {Jan}, pages = {81-85}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Levy EB} } @conference {38833, title = {The relation of the endocrine system to milk secretion and reproduction}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {3}, year = {1943}, month = {Jan}, pages = {20-25}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Campbell IL} } @conference {38837, title = {The spread and control of Mastitis}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {3}, year = {1943}, month = {Jan}, pages = {43-51}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Hopkirk CSM} } @conference {38836, title = {The theory and practice of mechanical milking}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {3}, year = {1943}, month = {Jan}, pages = {37-42}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Whittlestone WG} } @conference {38814, title = {Chairman{\textquoteright}s Opening Remarks}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {2}, year = {1942}, month = {Jan}, pages = {1}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McMeekan CP} } @conference {38818, title = {Chromium Oxide method for determining digestibility}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {2}, year = {1942}, month = {Jan}, pages = {21-22}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Barnicoat CR} } @conference {38822, title = {The crude fibre complex in animal nutrition}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {2}, year = {1942}, month = {Jan}, pages = {38-40}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Lancaster RS} } @conference {38815, title = {Dehydrated Meat}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {2}, year = {1942}, month = {Jan}, pages = {2-7}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Andrews JC} } @conference {38830, title = {District and seasonal influence on lactation curves in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {2}, year = {1942}, month = {Jan}, pages = {90-98}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Ward AH} } @conference {38827, title = {Extension work in dairy cattle feeding}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {2}, year = {1942}, month = {Jan}, pages = {76-79}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Nielsen EP} } @conference {38828, title = {A future for New Zealand Fisheries}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {2}, year = {1942}, month = {Jan}, pages = {80-83}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Richardson LR} } @conference {38823, title = {Grasslands and Forage Crops in Rotation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {2}, year = {1942}, month = {Jan}, pages = {41-51}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Levy EB} } @conference {38820, title = {Identical twins in dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {2}, year = {1942}, month = {Jan}, pages = {30-32}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Dry FW} } @conference {38829, title = {The influence of the animal on pasture production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {2}, year = {1942}, month = {Jan}, pages = {84-89}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Sears PD and Goodall VC} } @conference {38816, title = {Ketosis of dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {2}, year = {1942}, month = {Jan}, pages = {7-13}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Armstrong MC} } @conference {38819, title = {Nutrition and Animal Health in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {2}, year = {1942}, month = {Jan}, pages = {23-29}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Cunningham IJ} } @conference {38825, title = {Nutrition and the fleece}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {2}, year = {1942}, month = {Jan}, pages = {61-67}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McMahon PR} } @conference {38826, title = {The nutritive value of New Zealand lamb and mutton}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {2}, year = {1942}, month = {Jan}, pages = {68-75}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McMeekan CP and Clarke EA} } @conference {38821, title = {Problems of dairy-pasture feed supply}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {2}, year = {1942}, month = {Jan}, pages = {33-38}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Hamilton WM} } @conference {38817, title = {Sow Nutrition}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {2}, year = {1942}, month = {Jan}, pages = {14-20}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Ballinger CE} } @conference {38824, title = {On vaccine treatment for Mastitis}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {2}, year = {1942}, month = {Jan}, pages = {51-59}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Marples ME} } @conference {38813, title = {Artificial Insemination in Cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {1}, year = {1941}, month = {Jan}, pages = {58}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {James JP} } @conference {38805, title = {Birthcoat Characters and their Genetical Significance}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {1}, year = {1941}, month = {Jan}, pages = {13-17}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Dry FW} } @conference {38806, title = {Criteria of Male Fertility}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {1}, year = {1941}, month = {Jan}, pages = {18-24}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Blake TA} } @conference {38810, title = {Evaluation of the Fleece in Relation to Breeding Methods}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {1}, year = {1941}, month = {Jan}, pages = {44-49}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McMahon PR} } @conference {38809, title = {Field Surveys in Dairy Cattle Production Studies}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {1}, year = {1941}, month = {Jan}, pages = {38-43}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Ward AH} } @conference {38804, title = {Inheritance of Disease Resistance}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {1}, year = {1941}, month = {Jan}, pages = {8-12}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McLean JR} } @conference {38807, title = {Milk Production Studies}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {1}, year = {1941}, month = {Jan}, pages = {25-30}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Cooper MM} } @conference {38808, title = {Pasture Utilisation by the Animal}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {1}, year = {1941}, month = {Jan}, pages = {31-37}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Melville J and Sears PD} } @conference {38802, title = {President{\textquoteright}s Opening Address}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {1}, year = {1941}, month = {Jan}, pages = {1-2}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Ranstead JM} } @conference {38803, title = {Should a Breeder Tell?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {1}, year = {1941}, month = {Jan}, pages = {3-7}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Ranstead JM} } @conference {38812, title = {Statistical Methods in Animal Experimentation}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {1}, year = {1941}, month = {Jan}, pages = {57}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Campbell JT} } @conference {38811, title = {Technique in Meat Production Studies}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {1}, year = {1941}, month = {Jan}, pages = {50-56}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {McMeekan CP} }