Estimation of Variances and Covariances for Use in a Multiple Trait Beef Sire Evaluation Model

A modified maximum likelihood multiple trait procedure was used to estimate sire and error variances and covariances among calving ease, weaning weight, and yearling weight calf records. A description of the new method is presented. Data included 477 757 calves of 13 breeds of sire. Breeds of sire with over 9 000 calf records had genetic correlations between calving ease and growth traits that ranged from −.02 to −.43, and between weaning weight and yearling weight from.63 to.91. Heritability estimates for calving ease ranged from.07 to.30 for male calves and from.14 to.40 for female calves; for weaning weight from.12 to.31 for male calves and from.15 to.40 for female calves; and for yearling weight from.07 to.21 for male calves and from.17 to.52 for female calves. The residual error correlations between calving ease and the growth traits ranged from −.09 to.13 for male calves and from −.04 to.15 for female calves, and between weaning weight and yearling weight they varied around.7. The new estimates are recommended for use in multiple trait sire evaluation.