|Van Vleck, Lloyd|
Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: 3/1/1998
Publication Date: N/A
Technical Abstract: Estimates of (co)variance components and genetic parameters were obtained for weaning weight and several carcass traits using a derivative-free REML algorithm with animal models. Hot carcass weight, retail product percent- age, bone percentage, fat percentage, rib eye area, actual fat thickness and Warner-Bratzler shear force data were collected on 4071 two-breed cross ssteers. Weaning weight was recorded on these steers as well as on their paternal half-sib sisters and on the three-breed cross calves of those females (n=11,193 total records). Direct and maternal heritabilities for weaning weight were .25 plus/minus .03 and .16 plus/minus .03, respective- ly. The proportion of phenotype variance of weaning weight due to maternal permanent environmental effects was .17 plus/minus .03. Direct heritabil- ities for carcass traits were moderate to large in magnitude (.25 to .65). Correlation between direct and maternal additive genetic effects for wean- ing weight was negative (-.21 plus/minus .14). Direct genetic correlation for weaning weight with carcass traits were of small magnitude (-.10 to .08) except with hot carcass weight (.69) and with rib eye area (.25). Correlations between maternal genetic effects for weaning weight and direct genetic effects for carcass traits were of small magnitude (-.05 to .12) except for bone percentage (.58), although estiamtes may be associated with large sampling variance. In general, maternal ability for weaning weight does not seem to be highly correlated with carcass traits in steers.