Genetic parameter estimates based on selected and control beef cattle populations

Genetic parameters were estimated for birth weight, weaning weight, postweaning rate of gain and yearling weight from beef cattle data collected on populations subjected to selection as well as from data collected on genetic control populations. Heritability estimates for birth weight, weaning weight, postweaning rate of gain and yearling weight for genetic control males were 1.7, 1.3, 7.0 and 3.0 times larger, respectively, than estimates for select males. Corresponding values for genetic control females were 1.1, 2.4, 2.3 and 3.5 times larger than estimates for select females. Results obtained for the genetic correlations were more inconsistent than those obtained for the heritabilities; however, phenotypic correlations were similar for the genetic control and select population.