Proceedings of the New Zealand Society of Animal Production.
1986, 46: 87-92
Proceedings of the New Zealand Society of Animal Production.
1986, 46: 87-92
Single-born ewe hoggets were 2.7kg heavier than twins and 4.0kg heavier than triplets, and HFW differences were 0.07kg and 0.13kg respectively. Single-born ram hoggets were 2.9kg heavier than twins and 4.3kg heavier than triplets, HFW differences being 0.04kg and 0.10kg, respectively. Ewe hoggets reared by 3, 4 and 5 year old dams were 0.7, 1.2 and 1.4kg heavier than those reared by 2 year old dams, and the corresponding estimates for ram hoggets were 0.6, 1.8 and 1.3kg. Dam age did not significantly affect HFW; linear regression coefficients of the traits on age were 0.003kgd-1 (ewes) and 0.006kgd (rams) for HFW, and 0.04kgd-1 and 0.08 kgd-1 for HLW. The regression of HFW and HLW was 0.02kgkg-1.
Heritability estimates (from paternal half-sib analyses) for HFW were 0.52±0.05 (ewes) and 0.22±0.04 (rams), while HLW heritability estimates were 0.26±0.05 and 0.21±0.06. Genetic correlation estimates were 0.21±0.15 (ewes), -09.33±0.18 (rams) and 0.03±0.14 (combined-sex), while phenotypic correlation estimates ranged from 0.27 to 0.40.
Keywords: NZSAPAB; Fleece weight; live weight; Coopworth; heritability; genetic correlation; environmental effects; sheep; wool
