(Co) variance components and genetic parameters for birth weight (BW), adjusted weaning gain (AWG) and for conformation (WC), precocity (WP), muscling (WM) and size (WS) scores at weaning were estimated, from records of 40,915 Angus calves, raised in the state of Rio Grande do Sul, southern Brazil. From that data, 12,706 had birth weight records and 11,863 had complete records for visual scores (VS). The data were analyzed using an animal model, in uni and multivariate analyses, and the variance components estimated by restrict maximum likelihood. The direct additive heritabilities estimated were 0.29, 0.25, 0.18, 0.19, 0.19 and 0.21, respectively for BW, AWG, WC, WP, WM and WS. Maternal heritability for AWG was 0.16 and genetic correlation between direct and maternal effects was --0.51. This high negative correlation indicates antagonism between these effects and decreases total heritability for AWG to 0.18. The contribution of dam permanent environment to phenotypic variance was between a minimum of 0.05 for BW and a maximum of 0.12 for AWG. Genetic correlation between BW and AWG was --0.06, showing that these traits are genetically non-dependent. The genetic correlations found between AWG and VS were from 0.71 to 0.86, and among VS traits from 0.58 to 0.91. These positive associations among VS traits and these with pre-weaning growth phase, support the simultaneous selection of these traits, by means of selection indexes.
animal model; beef cattle; correlation; heritability
