Abstract

Hogget fleece weight (HFW) (n=10376) and live weight (HLW) records (n=5930) from a highly fecund Coopworth flock were analysed by least squares methods to obtain estimates of environmental effects, heritabilities and genetic and phenotypic correlations. 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

CA, Morris, RL Baker, and GL Bennett

Proceedings of the New Zealand Society of Animal Production, Volume 46, , 71-76, 1986