Genetic and Environmental Correlations between Weaning Scores and Subsequent Gains in the Feed Lot with Record of Performance Steers

Abstract

This analysis is based on 613 steers from 83 Hereford sires in experiments conducted by the United States Bureau of Animal Industry in cooperation with the Montana Agricultural Experiment Station. The variances and covariances of gains and weaning score were broken down into genetic and environmental influences. A gross correlation of 0.0001 was observed between score at weaning and gains in the feed lot. A genetic correlation of 0.300 and an environmental correlation of −0.304 were obtained. The heritability estimate for scores was 31 percent and for gains 70 percent. The negative environmental correlation may be due to (1) some compensating increased gains in the feed lot for the relatively poorer conditions of environment before weaning, or (2) negative correlation that may exist between milk production and gains. It is concluded that there is little value in selecting feeders for rapid gain if sole dependence is placed on visual method of selection.