@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 = {The effects of out-of-season breeding on plasma prolactin concentrations, wool production and lamb birth weight}, journal = {New Zealand Journal of Animal Science and Production}, volume = {81}, year = {2021}, month = {01/2022}, pages = {129-135}, address = {Online}, abstract = {Performance of autumn- and spring-lambing ewes was compared in a year-long trial. Ewes were shorn in November and mated to lamb in May or August. Midside wool samples and plasma were collected at seven-week intervals to determine wool-growth rate, fleece characteristics, and prolactin concentrations. Autumn lambs were lighter (P<0.001) at birth and weaning (3.92{\textpm}0.1; 15.6{\textpm}0.7 kg) than spring lambs (5.27{\textpm}0.1; 25.3{\textpm}0.7 kg). Plasma prolactin concentrations were high (150 ng/ml) at mating (Dec) of autumn-lambing ewes, but low (50 ng/ml) at mating (March) of spring-lambing ewes. Both groups exhibited periparturient prolactin surges, but in autumn-lambing ewes this created high plasma prolactin concentrations during early pregnancy when plasma prolactin is usually very low. In autumn-lambing ewes, clean fleece weights (3.75{\textpm}0.11 kg), midside wool growth over 345 d (374{\textpm}12 mg/cm2) and fibre diameter (39.8{\textpm}0.5 mm) were significantly higher (P<0.05) than those of spring-lambing ewes (3.26{\textpm}0.12 kg; 331{\textpm}14 mg/cm2; 38.2{\textpm}0.5 mm respectively) whilst bulk and colour did not differ. Bulk was higher (P<0.05) in single-bearing ewes (21.1{\textpm}0.4 cm3/g) than in twin-bearing ewes (19.2{\textpm}0.7 cm3/g). It is postulated that elevated plasma prolactin concentrations (at key times) are related to seasonal differences in birth and fleece weights. Autumn lambing is beneficial for wool growth but detrimental for lamb birth weight and growth. Keywords: out-of-season lambing; sheep; prolactin; wool growth; birth weight}, issn = {1176-5283}, author = {Peterson SW and Burnham DL and Morris ST} } @conference {3672, title = {The effect of yard weaning and contact with humans on behavioural reactivity and liveweight gain of beef breed calves}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {8-12}, address = {Rotorua}, abstract = {Yard weaning of beef-breed calves is growing in popularity in New Zealand as a way of improving ease of handling, but there is little scientific literature regarding the practice. This experiment examined the effects of yard weaning versus paddock weaning with and without human contact on liveweight gain and behaviour. Paddock-weaned calves lost more live weight in the first sev-en days after weaning (-1.19 {\textpm} 0.17 kg/d versus -0.60 {\textpm} 0.16 kg/d; P=0.01) than yard-weaned calves but live weight was similar between treatments 42 days after weaning (D42). Yard-weaned calves tended to be less reactive than paddock-weaned calves on D7 (2.16 {\textpm} 0.28 versus 2.92 {\textpm} 0.33; P= 0.07, where one is least reactive and five is most reactive), but there were no differences in reactivity on D42. Faecal corticosterone concentrations were similar between weaning location, however, calves with minimal human contact had higher faecal corticosterone concentrations 48 hours after weaning than did calves with daily human contact (27.6 {\textpm} 2.11 ng/ml versus 18.6 {\textpm} 2.11 ng/ml; P<0.01), regardless of location. There were short-term advantages in live weight and heart rate associated with yard weaning of beef-breed calves, but these did not persist to D42. }, issn = {1176-5283}, author = {Ramsay BA and Schoorl JAJ and Stayton KM and Cranston LM and Morris ST and Burnham DL and Cockrem JF and Beausoleil NJ and Hickson RE} } @conference {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 {60955, title = {The effect of fasting on live weight in hogget wethers and pregnant mature ewes : Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {112-114}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Withholding of food and water, or fasting, of sheep for up to 24 hours is a practice commonly employed in the agricultural industry and research sectors. Farmers routinely fast sheep before shearing, pregnancy scanning and transport. Further, with relatively large numbers of animals involved in some experiments, duration of weighing and manipulation time can vary, which may interfere with a comparison of live weight measurements. The determination of the rate of liveweight loss will allow live weights to be corrected to... Continued }, issn = {1176-5283}, author = {Burnham DL and Morel PCH and Kenyon PR and Morris ST and Stafford KJ} } @conference {41699, title = {To wether - short scrotum or leave lambs as entire rams ? Revisiting an old question using new genetics}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {67}, year = {2007}, month = {Jan}, pages = {44-47}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Wanaka}, abstract = {A comparison of wethers (WTH), short scrotum (SSC) and rams (RAM) was made on 552 7/16 Romney, 3/16 Poll Dorset, 3/16 Texel and 3/16 East Friesianlambs. Lambs were drafted for slaughter using commercial criteria on weight and condition score at weaning (D81), D120, D154 and D192. Due to faster growth rates, by the end of the 2nd kill (D120) approximately 31\% of RAM and SSC lambs were slaughtered compared with 16\% of WTH lambs (P<0.01), although the difference was no longer significant by the end of the 4 th kill. The carcass weight of WTH (17.6kg) was significantly heavier (P<0.01)than the RAM (17.2kg) but not significantly different to the SSC (17.5kg), despite similar kill liveweights, due to the increased dressing out percentages of the WTH lambs (43.6\%, 43.1\% and 42.5\% respectively; P<0.05). Based on GR, 8.7\% of WTH carcasses graded overfat, compared with only 0.6\% of RAM and SSC carcasses (P<0.001). Over the kill period the price schedule ($/kg carcass weight) dropped, so for the WTH given their longer time to slaughter and poorer grading due to over fat carcasses the price for WTH carcasses ($49.16) was lower (P<0.01) than RAM or SSC carcasses ($50.37 and $50.70). When the added cost of feeding and drenching was taken into consideration, the net value of the WTH was evenless. Composite wether lambs of still potentially present an opportunity cost, except incertain situations where the management benefits outweigh the direct financial cost. }, issn = {1176-5283}, author = {PL Johnson and Kenyon PR and Burnham DL and West DM} } @conference {41831, title = {Relationships between on-farm and pre-slaughter behaviour and growth and meat quality for bulls and steers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {261-265}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Angus and Hereford-Angus cross bulls (n = 58) and steers (n = 59) were assessed for temperament 3 times during post-weaning growth and for behaviour during pre-slaughter holding in order to investigate relationships between these traits and measures of growth and meat quality including meat tenderness and meat colour. Composite on-farm temperament scores encompassed measures during weighing of stepping and unease on the scale, and speed of movement and level of agitation when released from the scale. Pre-slaughter assessments included counts of butting, pushing, fighting and mounting. Plasma levels of cortisol, glucose, lactate and fatty acids at slaughter were measured. On-farm temperament scores were significantly correlated (P < 0.0001) between the 3 times and between measures within a time. On-farm measures, however, were not related to pre-slaughter scores or to plasma cortisol or metabolite levels. Plasma cortisol levels were significantly higher for steers than bulls (43.8 vs 22.4 ng/ml; P < 0.001) as reported previously, and bulls had significantly higher pre-slaughter behaviour scores, but there were no castration effects on levels of plasma metabolites or on-farm temperament scores. Relationships between behavioural traits and measures of growth rate and meat quality based on treatment-adjusted residuals were low and non-significant. It is concluded that despite on-farm temperament scores being moderately repeatable, these measures were not associated with differences in pre-slaughter behaviour, and neither of these traits was associated with growth rate or measures of meat quality. KEYWORDS: animal behaviour; meat quality; meat pH; cortisol; growth rate; tenderness. }, issn = {1176-5283}, author = {Burnham DL and Purchas RW and Morris ST} } @conference {41499, title = {Manipulating lamb birth weight and survival rate in singletons born to hoggets}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {175-178}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Lambs born to hoggets tend to be relatively lightweight at birth (Drymundsson, 1973; McMillan \& McDonald, 1983) and display low survival rates to weaning (McCall \& Hight 1981; McMillan \& McDonald, 1983). In addition the incidence of singletons in hoggets often exceeds 92\% (McCall \& Hight, 1981; McMillan \& McDonald, 1983). Therefore management procedures that improve both birth weight and survival of singleton lambs should have a significant effect on returns. Severe under nutrition during pregnancy of mature ewes can lead to reduced ewe and lamb performance (Rattray 1986), which can negatively affect lamb survival. However to date minimal research under New Zealand{\textquoteright}s pastoral conditions has been undertaken in hoggets. In contrast to the mature ewe, it is also advantageous for the hogget to be increasing in conceptus-free live weight during pregnancy if lifetime performance is not to be negatively affected. Interestingly, under concentrate feeding regimes in the United Kingdom it has been reported that a high level of hogget nutrition in pregnancy, actually reduces both lamb birth weight and survival (Wallace et al., 1996). Shearing mature ewes in mid- to late-pregnancy has been shown to differentially increase singleton- (Morris et al., 2000; Kenyon et al., 2002a) and twin-lamb birth weights (Morris \& McCutcheon, 1997; Morris et al., 1999; Kenyon et al., 2002b). Mid-pregnancy shearing has tended to increase twin-lamb survival rates (Morris et al., 1999; Kenyon et al., 2002b) but has been found to decrease singleton survival rates in one of four studies (Kenyon 2002). The effect of mid- to late-pregnancy shearing of hoggets has not been examined under pastoral conditions in New Zealand. Due to the low rate of twin pregnancies in hogget{\textquoteright}s the chance of achieving a positive affect from mid-pregnancy shearing on both a lamb birth weight and survival may be low. The aims of these studies were to determine if hogget live weight change and shearing treatment during pregnancy could be used to manipulate singleton lamb birth weight and survival. }, issn = {1176-5283}, author = {Kenyon PR and Morris ST and West DM and Stafford KJ and Corner RA and Ottema K and Burnham DL} } @conference {41427, title = {The effect of sward height on twin and triplet lamb birth weights and survival rates to weaning}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {63}, year = {2003}, month = {Jan}, pages = {152-154}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Queenstown}, abstract = {The differential allocation of pasture between ewes of different bearing/rearing ranks requires a knowledge of the relationship between herbage allowance, intake and production. Few experiments have been conducted in which responses to different pasture allowances have been examined for triplet-bearing/rearing ewes, particularly under continuous stocking management. Published feed requirements for ewes rearing triplets have often been extrapolated from those defined for twin-rearing ewes (Geenty \& Rattray 1987). The sward surface guidelines for feeding single- and twin-bearing ewes have been published and researched under New Zealand conditions (Parker \& McCutcheon 1992; Morris et al., 1993a, 1993b; Morris et al., 1994). There is anecdotal evidence for varying lambing performance and lamb growth rates for triplet-bearing/rearing ewes under pastoral grazing conditions. The national average lambing percentage is increasing to beyond 120\% (MWIES 2002). The proportion of triplets in flocks lambing above 150\% increases at the expense of single-born lambs (Amer et al., 1999). The aim of the research communicated in this paper was to compare ewe and lamb performance in twin- and triplet-bearing/rearing ewes offered various sward height allowances. }, issn = {1176-5283}, author = {Morris ST and Kenyon PR and Burnham DL and Everett-Hincks JM} } @conference {41369, title = {Subclinical Johne{\textquoteright}s Disease in Sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {62}, year = {2002}, month = {Jan}, pages = {284-287}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {

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

}, issn = {1176-5283}, author = {Thompson KG and West DM and Anderson PVA and Burnham DL} } @conference {40958, title = {Short-Term Grain Feeding and its Effect on Carcass and Meat Quality.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {57}, year = {1997}, month = {Jan}, pages = {275-277}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Forty-five crossbred steers weighing 540-580 kg were assigned to three treatment groups. Group 1 received pasture only for 58 days; Group 2 grazed at a similar herbage mass to Group 1 and were supplemented with 4 kg/hd/day of a concentrate ration; Group 3 were on a feedlot and fed 8 kg/hd/day of concentrate together with 2.0 kg/hd/day of straw. Groups 2 and 3 each had a 28 day pre-conditioning period followed by a 30 day concentrate feeding period. Final fasted liveweight, liveweight gains, and carcass weights for concentrate, concentrate plus pasture and pasture alone groups were 546 {\textpm} 9, 548 {\textpm} 9, 547 {\textpm} 8 kg; 0.33 {\textpm} 0.09, 0.42 {\textpm} 0.09, -0.05 {\textpm} 0.09 kg/hd/day and 293 {\textpm} 7, 315 {\textpm} 4 and 313 {\textpm} 4 kg, respectively. The concentrate plus pasture and pasture only fed groups had greater fat depths. Ultimate pH was slightly lower in concentrate fed than pasture fed cattle but there were no differences in fat colour or tenderness as measured in the laboratory. Plasma carotene levels were significantly lowered by a factor of 10 in the concentrate fed group compared to the grass fed group, but this did not affect fat colour when measured subjectively at the meat processing plant or objectively in the laboratory. Apparently feeding concentrates for 30 days is insufficient to affect fat colour characteristics. }, issn = {1176-5283}, author = {Morris ST and Purchas RW and Burnham DL} } @conference {40848, title = {The effect of shearing by cover comb or blades on the resistance of sheep to cold, windy and wet conditions}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {332-333}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Four pairs (total 8 sheep) of Romney mixed-age ewes were housed indoors and fed chaffed lucerne hay at a level equivalent to 1.2 times maintenance. Oxygen consumption was measured in two open circuit calorimeter chambers on days -3, -2, 0, 2, 6 and 10 with day 0 being day of shearing. On each measurement day, oxygen consumption was measured under two sets of climatic conditions (cold plus wind, followed by cold plus wind plus rain). Differences in live weight, fleece weight and liveweight gain of the ewes were not statistically significant. The difference in the rate of oxygen consumption (litres/kg0.75/hour) between cover comb and blade shorn-sheep was not significant during the cold+wind conditions. However, when }, issn = {1176-5283}, author = {Burnham DL and Holmes CW and Morris ST and Parker WJ and Kidd RI} } @conference {40869, title = {Plasma carotenoid concentrations early in life can be used as a selection criterion for fat colour in heifers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {398-399}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Plasma carotenoid (PC) concentrations were measured at 2-5 month intervals in 20 Hereford x Jersey (HJ) and 20 Hereford x Friesian (HF) once bred heifers from 10-35 months-of-age. Half of the heifers were slaughtered at 31 months-of-age and the rest at 35 months-of-age. The colour of the subcutaneous and intermuscular fat was measured using a chromameter and c* values were calculated. Subcutaneous and intermuscular fats in HJ heifers were yellower (i.e. they had higher c* values) than in HF heifers. Regression equations that included breed, date of slaughter and PC concentrations at 10-12 months-of-age, accounted for 56\% of the variation in c* values for subcutaneous fat and 40\% of the variation in c* values for intermuscular fat (P<0.001). }, issn = {1176-5283}, author = {Death AF and Knight TW and Purchas RW and Morris ST and Burnham DL} } @conference {40567, title = {The effect of pasture height on herbage intake and ewe production under continuous stocking management during the autumn.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {75-78}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A replicated trial design with ewes continuously stocked on mixed ryegrass/white clover pastures at three target sward surface heights (SSH) of 4, 6 and 8 cm, and 16 ewes per sward treatment (total 96 ewes), was carried out from February through to April 1993. Herbage intake was assessed indirectly from faecal output measured using chromium controlled release capsules and the in vitro digestibility of herbage samples obtained from oesophageal- fistulated sheep run with the ewes. Intake measurements were taken before and after the rams were joined with the ewes. Pasture measurements for the 4, 6 and 8 cm SSH treatments were: SSH, 4.12 vs 6.18 vs 7.97 cm (PSE 0.54 cm, P<0.05); mass, 3358 vs 4291 vs 5231 kg DM/ha (PSE 389 kg DM/ha, P<0.1); dead mater content, 38.9 vs 26.7 vs 40.4\% (PSE 5.8\%, NS); and organic matter digestibility, 68.0 vs 71.9 vs 63.8\% (PSE 1.21\%, P<0.0001). Organic Matter (OM) intakes fro the 4, 6 and 8 cm SSH treatments were 1.39 vs 1.86 vs 1.06 kg OM/ewe/day (PSE 0.08 kg OM/ewe/day, P<0.05) for the pre-mating intake and 1.26 vs 1.34 vs. 1.09 kg OM/head/day (PSE 0.06 kg OM/ewe/day, NS) for the mating intake period. Production responses of the ewes for the 4, 6 and 8 cm SSH treatments were: liveweight gain, 72 vs 83 vs. 73 g/day (PSE 5 g/day, NS); and wool growth rate, 1.37 vs 1.44 vs 1.42 mg/cm2/day (PSE 0.03 mg/cm2/day, NS). These results suggest that, in the autumn, maximum herbage intake and ewe performance on ryegrass - white clover pastures can be obtained at a sward height of about 4 cm, and that pasture digestibility and dead matter content in the pastures are the major limiting factors at this time of year. }, issn = {1176-5283}, author = {Burnham DL and Parker WJ and Morris ST} } @conference {40624, title = {The effects of restricted suckling and prepartum nutritional level on reproductive performance of primiparous crossbred beef cows.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {307-310}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Reproductive performance was recorded in a total of 21 two-year-old Hereford x Friesian and Simmental x Friesian primiparous cows before and after restriction of calf suckling. Cows were allocated one of two pastures allowances from day 112 to 212 of gestation so that the high nutrition (HN) group gained 0.75 kg/d, and the low nutrition (LN) group gained 0.17 kg/d during mid-gestation. Suckling was suppressed for 7 days by fitting nose plates to 46-day-old calves in the restricted suckling (RS) group, whereas the normal suckling (NS) group remained as a control. Dominant follicles in the ovaries occurred in all cows by day 32 post partum and underwent a pattern of growth and atresia before first ovulation. Restricted suckling cows had a shorter interval from calving to conception than NS cows (76.0 {\textpm} 5 vs 94.1 {\textpm} 6 days, P<0.05, whereas genotype and nutritional treatment had no effect on interval to conception. However, the beneficial effect of suckling restriction on days from calving to conception only occurred in cows fed the high herbage allowance in mid-gestation. RS calves spent more time grazing during the period of attachment of nose plates and differences in behaviour remained over a further 5 days after nose plates were removed (62.4 {\textpm} 7 vs 38.6 {\textpm} 7 minutes spent grazing; P<0.001), but were lighter at weaning (146.7 {\textpm} 3 vs 162.4 {\textpm} 3 kg; P<0.01). Despite the lower calf liveweight at weaning it is concluded that manipulation of suckling through fitting nose plates to calves can be used to initiate earlier re-breeding in primiparous cows. }, issn = {1176-5283}, author = {De Nava Silva GT and Burnham DL and McDonald MF and Morris ST} } @conference {40444, title = {Herbage allowance - intake - production relationships in continuously stocked winter- and spring-lambing ewes}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {11-14}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The potential of by-products from fruit and vegetable growers and processors to serve as supplementary feeds for dairy cows in the Hawkes Bay region, which traditionally experiences poor summer pasture growth, was assessed. A total of 75 000 tonnes (wet matter) of by- products were produced by the six growers and processors surveyed, mainly between January and June. Peak by-product output occurred in April when an estimated 15,000 tonnes of wet matter was produced. Industry disposal costs ranged from $10 to $33/tonne wet matter. The metabolisable energy values (MJ ME/kg DM) of by-products were at least equivalent to those of high quality spring pasture (e.g. carrot 11.3, apple pomace 13.7), but nitrogen levels (\% in DM) were low compared to those recorded in pasture (e.g. corn 1.0\%, apple pomace 1.9\%). A linear programming analysis of a Hawkes Bay dairy farm indicated that farmers could afford to pay up to 15.5 cents/kg DM for additional feed from May to October and 26.7 cent/s kg DM during the remainder of the year if milkfat prices were $6/kg. These shadow values indicate the maximum price that could be paid for transport and feeding costs for by-products on the model farm.}, issn = {1176-5283}, author = {Morris ST and Parker WJ and Burnham DL and Reynolds GW and McCutcheon SN} }