@conference {41198,
	title = {Genetic parameters for improvement of dual-purpose flock productivity with constraints on mature ewe body weight},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {60},
	year = {2000},
	month = {Jan},
	pages = {203-206},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Hamilton},
	abstract = {SIL provides opportunity for inclusion of information on mature ewe body weight in animal evaluations. This paper reports estimates of the parameters needed for these evaluations. Traits analysed were: weaning weight (WWT) and hogget liveweight in May (ALW); hogget yearling liveweight (HLW) and greasy fleece weight (HFW); and pre-mating body weights (ELW), number of lambs born (NLB) and greasy fleece weights of ewes at 2 to 5 years of age. EFW and especially ELW, were highly repeatable (>0.9), the pattern of genetic correlations suggesting that breeding ewes had reached maturity in these traits by 40 months of age. Direct and maternal genetic effects on WWT showed similar heritabilities (0.14{\textpm}0.02 \& 0.18{\textpm}0.02) and were positively correlated (0.20{\textpm}0.08). Maternal influences on traits measured at old ages were much reduced, direct heritabilities being similar to published estimates. WWT showed a high direct genetic correlation with LW8 and HLW (0.82{\textpm}0.02), but lower with ELW (0.70{\textpm}0.06 for 3-year old ewes). LW8 and HLW showed even higher direct genetic correlations with ELW (of the order of 0.90{\textpm}0.02). EFW was highly correlated genetically with HFW (0.80{\textpm}0.03), HLW (0.25{\textpm}0.04), ELW (0.23{\textpm}0.05) and LW8 (0.21{\textpm}0.04). Dual-purpose genetic response predictions were derived using SIL{\textquoteright}s recently revised relative economic values for a dual-purpose index. Its correlation with aggregate breeding value was 0.67. It predicted positive selection responses (per generation and standard deviation of selection pressure) in all traits: LW8 (2.1 kg), EFW (0.14 kg), NLB (0.038 lambs/ewe) and ELW (2.4 kg or 87\% of the predicted single trait response despite the negative economic weight for this trait). Restraining the response in ELW to zero required a ten-fold increase in the negative relative economic value for this trait, and reduced the correlation of the index with aggregate breeding merit to 58\% of its previous value. Such restriction greatly increased the relative contribution of fleece weight to economic response, made little difference to the contribution of NLB (although the absolute rate of progress was nearly halved), and reduced the contribution of growth; maternal effects on weaning weight became relatively more important. },
	issn = {1176-5283},
	author = {Clarke JN and Dobbie JL and Jones KR and Wrigglesworth AL and Hickey SM}
}
@conference {41063,
	title = {Sex and age effects on genetic parameters for wool production and qualities},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {59},
	year = {1999},
	month = {Jan},
	pages = {23-26},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Heritabilities and genetic correlations were estimated for New Zealand Romney sheep from within the selected and control lines of a 25-year selection experiment for greasy hogget fleece weight and yearling body weight. Average repeatability of clean fleece weight in 1 to 5 year-old ewes was 0.56, 25\% higher than the average heritability of 0.44. The average genetic correlation among measurements at different ages was 0.89. Sexual dichotomy in the relative predictive power of hogget records was most apparent for greasy and clean fleece weights but was evident to some degree for bulk and brightness as well, due mainly to lower heritabilities in male compared to female hoggets. Average co-heritability of greasy hogget with adult clean fleece weights was 25\% lower for male (0.26) compared to female (0.35) hoggets, in this case due to a lower genetic correlation (0.69 vs 0.81) as well as a lower heritability (0.33 vs 0.43, respectively). A repeatability model seemed an adequate approximation for estimation of breeding merit for most wool quality traits studied but not for lifetime wool production. },
	issn = {1176-5283},
	author = {Clarke JN and Dobbie JL and Jones KR and Wrigglesworth AL and Hickey SM}
}
@conference {40955,
	title = {Comparison of weight-selected Romney hoggets for growth and ultrasonic fat and eye muscle dimensions.},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {57},
	year = {1997},
	month = {Jan},
	pages = {263-266},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Lines of Romney sheep selected for either weaning (WWW) or yearling body weight (TYW and HYW) for 25 years were compared relative to their respective controls in a common environment using two unselected crops of male and female progeny. The weaning weight (WWW) line and one of the yearling weight (TYW) lines were derived from a common base flock, of diverse origin. The WWW line maintained a similar body weight advantage of approximately 20\% over its control at 5, 8, 10 and 14 months of age. All control lines showed very similar average body weight trends with age (28.0{\textpm}0.5, 33.9{\textpm}0.05, 35.3{\textpm}0.06 and 42.6{\textpm}0.7). In contrast the yearling weight lines showed increasing divergence with age from 22\% in February to 28\% (TYW) and 31\% (HYW) at 13 months. All lines, and especially the yearling weight lines showed some weight increase over the winter (May to July). Eye muscle depth and width changed little over the winter compared with the previous autumn or the following spring, in contrast to fat depth trends which increased in all lines but for which however, there was little line divergence among the yearling weight lines during the winter. All selected lines had significantly lower eye muscle dimensions at the same liveweight than their controls (by 4\% for width and 5\% for depth). Lines also showed contrasting divergence in average weight-adjusted fat depth relative to their controls, especially those derived from the same base population. As judged by reductions in subcutaneous fat depth, the WWW line lost its initial leanness superiority (4\% lower fat depth) during the winter, the TYW line increasing its superiority (16-17\% lower fat depth) during the winter and spring. The other yearling liveweight line (HYW) showed only half the leanness superiority over its control at these times. Thus, lines selected for improved growth alone had different patterns of muscle and especially subcutaneous fat development in a desirable direction for commercial lean lamb production, but responses were variable. },
	issn = {1176-5283},
	author = {Clarke JN and Dobbie JL and Jones KR and Uljee AE and Wrigglesworth AL}
}
@conference {40961,
	title = {The role of calsequestrin in muscle function.},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {57},
	year = {1997},
	month = {Jan},
	pages = {286},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Meat quality depends on muscle quality which is related to the regulation of muscle function by the contrac-tion-inducing ion, calcium. If the process of Ca 2+ uptake, sequestration or release at the level of the muscle cell is interrupted or altered, there is a loss of muscle quality. Two well-characterized conditions that result directly from al-tered Ca2+ regulation are porcine malignant hyperthermia and chicken crook neck syndrome.},
	issn = {1176-5283},
	author = {Trumble W and Wesson C and Jones KR and Uljee AE and Wrigglesworth AL}
}
@conference {40732,
	title = {Genetic parameters of lifetime wool production},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {55},
	year = {1995},
	month = {Jan},
	pages = {268-271},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Heritabilities and genetic correlations were estimated from the selected  and control lines of a 25-year selection experiment for hogget greasy fleece  weight (GFW). The heritability of GFW was higher in the selected than the  control line and in female hoggets (0.48) compared with males (0.32). Inter-  age genetic correlations were less than unity, and higher in fleece weight  selected animals. Average genetic correlations between hogget and adult  records were higher in ewe than ram hoggets. Together these parameters  gave co-heritability estimates (pooled across lines) for greasy hogget with  clean adult ewe fleece weights of nearly half the average magnitude in males  (0.21) compared with female (0.36). These results have important  repercussions to the design of effective selection strategies for improvement  of lifetime wool production.  },
	issn = {1176-5283},
	author = {Clarke JN and Dobbie JL and Hickey SM and Jones KR and Wrigglesworth AL}
}
@conference {40529,
	title = {Plasma prolactin in Romney sheep selected for hogget fleece weight},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {53},
	year = {1993},
	month = {Jan},
	pages = {371-376},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Seventy nine mature, alpacas were scanned every 10-14 days using real time ultrasonography to visualise the foetus. There was a 24\% foetal loss between days 21-30 of gestation and parturition, with the maximum loss occurring between days 21-30 and days 31-40 of gestation. There was a 5\% loss of foetuses after day 100 of gestation.},
	issn = {1176-5283},
	author = {Clarke JN and Pearson AJ and Sumner RMW and Johnson DL and Dobbie JL and Wildermoth JE and Wrigglesworth AL}
}
