@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 = {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 = {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: 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: 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 = {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 = {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 = {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 = {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 = {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 = {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} } @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: 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 = {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 = {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 = {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 {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 {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: 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: 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: 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 = {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 = {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {41191, title = {Sheep industry structure and genetic improvement}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {60}, year = {2000}, month = {Jan}, pages = {175-179}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {The sheep industry consists of a nucleus or ram-breeding sector that accounts for 1-2\% breeding ewes and a commercial sector that relies on the ram-breeding sector for the supply of flock rams. The rate of genetic change in the whole industry is dictated by the rate of genetic gain in the nucleus sector. Increasing the size of the nucleus sector has little affect on genetic gain but increases the costs of genetic improvement. Industry structure is determined by the behaviour of breeders and farmers but there is often little individual incentive for these players to alter their practices despite overall benefit to the industry. The advent of performance recording, open-nucleus breeding schemes and the introduction of new sheep breeds have all resulted in modifications to the NZ breeding industry structure. The introduction of new biotechnology, notably DNA and cloning technologies could markedly alter future industry structure. }, issn = {1176-5283}, author = {Garrick DJ and Blair HT and Clarke JN} } @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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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} }