@conference {39994,
	title = {Prediction of ewe mutton carcass composition from carcass weight, GR and C measurements, and the Hennessy grading probe},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {46},
	year = {1986},
	month = {Jan},
	pages = {59-62},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Fourteen herd-years of data, comprising a total of 2169 records, were obtained from beef heifers involved in the Ruakura Genetics Section{\textquoteright}s long term breeding trials. The contributions of breed-cross, weight selection , herd year, birth date and age of dam, to variation in live weight, proportion exhibiting oestrus and proportion pregnant were studied. For heifers reaching first oestrus by about 15 months of age, means ages and weights at puberty were also calculated. Later-born calves were younger and lighter at puberty than average. Younger dams produced heifer offspring which reached puberty when older but lighter than average. Breed and location differences were greater for proportions of heifers expressing oestrus before joining than for proportions pregnant. At Goudies, the proportion achieving oestrus among Jersey x Angus heifers was 0.72, Friesian-cross 0.61, Hereford x Angus 0.47, Hereford 0.38 and Angus 0.25. Corresponding proportions diagnosed pregnant after 8 weeks of mating were 0.83, 0.93, 0.83, 0.78 and 0.73. Where there were major feed shortages over an extended period between 5 and 15 months of age, live weights and pubertal age were more affected than pubertal weight. In contrast, long term weight selection increased pubertal weight by 11\%, while pubertal age was little changed. Preliminary estimates of heritability for pubertal age and weight were 0.31},
	issn = {1176-5283},
	author = {Kirton AH and Feist CL and Duganzich DM}
}
@conference {39944,
	title = {Prediction of lamb carcass composition from GR and carcass weight},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {45},
	year = {1985},
	month = {Jan},
	pages = {63-66},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {A lean-growth index (LGI) incorporating growth rate and the proportion of that growth which is fat is calculated by first converting live-weight differences into differences in weight of lean tissue and then adjusting these values using an estimated breeding value for fat depth. The adjustment of fat depths for weight is by within-flock double-log regression or by specifying a constant exponent in the relationship between fat depth C and live weight. Simulation studies suggested that the constant-exponent method was superior for smaller groups of sheep. Improvements in LGI by selection appear more likely to arise from genetic increases in growth rate than from decreases in weight-corrected fatness, but the inclusion of fatness in the index should lead to the production of lambs that can be taken to heavier weights before becoming overfat.},
	issn = {1176-5283},
	author = {Kirton AH and Duganzich DM and Feist CL and Bennett GL and Woods EG}
}
