@conference {41159,
	title = {The effects of shearing Finnish Landrace x Romney ewes in mid-pregnancy on lamb survival, birth and other weights},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {60},
	year = {2000},
	month = {Jan},
	pages = {58-60},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Hamilton},
	abstract = {In each of 2 years, 600 Finnish Landrace x Romney ewes were subjected to a range of nutrition levels in early to mid pregnancy. Half the ewes were then shorn at day 70 of pregnancy with a standard comb. In the first year (1997), shearing treatment had no impact on single lamb birth and weaning weights, which were 5 and 29 kg respectively. Treatment improved twin lamb birth weights by 0.2 kg (P< 0.10), and weaning weight 1.4 kg (P<0.10). In the second year (1998), shearing treatment benefited single lamb birth weight (0.2kg; P< 0.10), and weaning weight (1kg; P<0.01) and improved twin lamb birth weight by 0.2 kg (P<0.01). In both years, lambing rate and survival were not affected. Ewe weaning weight, also in both years, was slightly higher in the ewes shorn at day 70 of pregnancy (P< 0.05). },
	issn = {1176-5283},
	author = {Smeaton DC and Webby RW and Tarbotton IS and Clayton JB}
}
@conference {41041,
	title = {Productivity and Profitability of Twinning Beef Cows},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {58},
	year = {1998},
	month = {Jan},
	pages = {245-247},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Twinning Hereford x Friesian beef cows were run in farmlets with breeding ewes at Whatawhata Research Centre. The additional inputs and outputs of twinning cows were compared with those of single calving treatments. This was carried out in a farm systems environment so that the feed-back mechanisms inherent in biological systems could operate. Typically, the twinning beef cows lost 15\% of their foetuses during pregnancy and had (in the most recent year) a calf survival rate of 80\%. Comparable figures for single calving cows were 5 and 95\% respectively. Twin calves weighed 200 kg at weaning compared to 240 kg for singles. The twin cow farmlets required 250 kg extra DM/cow and 5.7 extra hours of labour/cow at calving. The sheep were not measurably affected by cow treatment. Gross margin analyses using these and other trial data indicated that twinning cows were $44/cow less profitable than single cows. Further analyses showed however, that the twinning cow system would breakeven with the singles if any one of the following changes were possible, (1) twin calf wean weight 220kg, (2) twin calf survival 89\%, (3) twin foetal loss 5\%, (4) labour differences dropped from 5.5 (above) to 2.1 hours/cow. When all the breakeven values were assumed to have occurred at the same time, twin cows were $120/cow more profitable than single cows. This is the money available to pay for extra risk and the extra cost of getting a cow twin pregnant (at day 60) compared to single pregnant. },
	issn = {1176-5283},
	author = {Smeaton DC and Clayton JB}
}
@conference {40682,
	title = {Effects of genotype and nutrition on sheep carcass fat and eye muscle development between weaning and 14 months of age},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {55},
	year = {1995},
	month = {Jan},
	pages = {104-107},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Although several studies have implicated cortisol in the control of  body composition in sheep, the precise mechanisms are unclear. Cortisol  basal concentration and response to an ACTH challenge was studied in  Coopworth wethers selected for (Fat) or against (Lean) fatness in both the  fed and 48 hour fasted states at two stages (15 and 33 weeks). The aim was  to investigate whether fasting, age or genotype would influence cortisol  secretory parameters.   Mean basal cortisol concentration was higher for fasted than fed lambs (13.6  versus 8.9 ng/ml, p<0.001), but did not differ significantly with genotype or  overall stage of development. Maximal cortisol response to ACTH was  greater for the fat than the lean genotype, at both 15 weeks (86.3 versus 65.3  ng/ml, p<0.01) and 33 weeks (108.2 versus 91.1 ng/ml, p<0.01) of age.   Maximal cortisol response was also significantly greater with fasting and  increasing age, but the effect of fasting on cortisol increase was greater at 15  than 33 weeks of age. Clearance of cortisol was significantly slower after  fasting, but unaffected (p>0.05) by genotype and development.   Basal cortisol concentrations was not associated with differences in body  composition between the fat and lean genotypes. However the larger  maximal response in the fat genotype may indicate that the adrenal gland  plays a role in determining body composition.  },
	issn = {1176-5283},
	author = {Binnie DB and Clarke JN and Clayton JB and Mowat CM and Purchas RW}
}
@conference {40699,
	title = {Estimated pasture intake and cow output of single and twin calving beef breeding cows},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {55},
	year = {1995},
	month = {Jan},
	pages = {161-164},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Thirty-eight adult Merino breeding ewes were drenched with Ivomec  and given a controlled release anthelmintic (benzimidazole) capsule in  August 1992 and December 1993.   Mean FEC in the Untreated group peaked over lambing at 600epg in 1992  and 800epg in 1993. Mean FEC in the Treated group remained below 50epg  during the active period of the capsule. The Treated ewes had a higher  survival rate, were heavier, grew more wool from late July 1993 and weaned  more and heavier lambs in 1993 than the Untreated ewes.   At a mean Merino wool price of 500c/kg greasy, returns from the increased  wool production more than equates with the anthelmintic treatment cost.   Increased returns would be gained from improve ewe survival and increased  lamb production.  },
	issn = {1176-5283},
	author = {Bown MD and Clayton JB and McMillan WH and Smeaton DC}
}
@conference {40435,
	title = {Management effects on seasonal fibre quality in Angora goats},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {52},
	year = {1992},
	month = {Jan},
	pages = {293-296},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Lambs grazing ryegrass infected with endophyte (Acremonium lolii) may exhibit staggers or diarrhoea or both, with little correlation between these two conditions. Associated mycotoxins/toxins other than the staggers-inducing lolitrems are likely to be responsible for metabolic changes causing reduced intake, elevated temperature and diarrhoea. These mycotoxins are not necessarily confined to the base of the leaf sheath and stem as is the case for lolitrems. The distribution of mycotoxins to proximal portions of vegetative ryegrass and the effect of these plant components on grazing animals was investigated. Following experimental confirmation in 1991 of nil correlation between staggers and diarrhoea, groups of lambs were grazed in autumn 1992 on 100\% endophyte-infected hybrid ryegrass cv. Grasslands Marsden (Lollium boucheanum Kunth.), using a leader-follower system. Upper and lower leaves, and pseudostem were progressively removed by four groups of lambs on three day breaks, replicated twice. Liveweight gain ranged from 164 g/day in lambs having first offer, to 28 g/day in those grazing the base of the plants (P<0.01). Rectal temperature averaged 40.2 C being slightly above normal in all treatments. Faecal moisture was high; ranging from 79-87\% throughout the experiment with no significant differences due to treatment. Observed faecal soiling was greatest in lambs receiving high leaf component (P<0.05). Clinical staggers, barely detectable in lambs grazing leaf, became severe as the proportion of pseudostem in the diet increased (P<0.01). In contrast to the clear association between endophyte and staggers in lambs grazing the base of infected ryegrass, consistently high faecal moisture, and consequent faecal soiling occurred regardless of the part of the plant consumed, but tended to be greatest in lambs grazing leaf. Analysis of plant components suggested that peramines may be associated with this problem.},
	issn = {1176-5283},
	author = {Bown MD and Clayton JB and Bigham ML}
}
@conference {40236,
	title = {Nutrition effects on fibre quality in Angora goats during spring},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {50},
	year = {1990},
	month = {Jan},
	pages = {323-328},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {No abstract supplied   },
	issn = {1176-5283},
	author = {Bigham ML and Bown MD and Clayton JB}
}
@conference {40159,
	title = {Nutrition effects on live weight and reproduction of Cashmere doe hoggets},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {49},
	year = {1989},
	month = {Jan},
	pages = {157-162},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Often effective breeding programmes are dependent on the assumption that heritabilities and genetic correlations between traits are the same in both sexes and that the genetic correlation for the same trait measured on both sexes is unity. A total of 12 302 records from 149 sire groups were analysed using mixed model techniques to test these assumptions. The results provide an indication that genetic and phenotypic parameters differ for male and female sheep. Cognizance of this fact should be taken when considering alternative selection strategies.},
	issn = {1176-5283},
	author = {McCall DG and Clayton JB and Dow BW}
}
@conference {40012,
	title = {Calving date effects on beef cow productivity},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {46},
	year = {1986},
	month = {Jan},
	pages = {149-152},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {An agonist of gonadotrophin releasing hormone (GnRH) improves dairy cow pregnancy rates when injected at an appropriate stage after insemination. These studies were extended to ewes and hoggets in a series of trials to determine the effects of a single injection of GnRH made at varied intervals after mating. All sheep were mated at a synchronised oestrus (day of oestrus = day 0) with treated ewes being injected on a set date with 2 or 4 },
	issn = {1176-5283},
	author = {Smeaton DC and McCall DG and Clayton JB and Dow BW}
}
