Genetic and phenotypic parameters for pre-weaning growth and weaning conformation of Angus cattle

Abstract

Weaning weight (WW) and conformation score (CS) records on Angus calves from four New South Wales herds were analysed by least-squares procedures. Paternal half-sib components of variance and covariance were used to obtain estimates of heritabilities of various measures of growth and cs, as well as genetic, phenotypic and environmental correlations. Estimates of the heritabilities of measures of growth ranged from 0.20 (all data) to 0.24 when derived from heifer data only. The heritability of cs was 0.24 when the data were adjusted for ww, and 0.19 when no covariate was included in the analysis. All correlations among different measures of growth were positive and close to unity. There were small positive phenotypic and environmental correlations (0.19 to 0.36) and small negative genetic correlations between ww and cs (–0.02 to –0.41).