Abstract
A specific procedure for the within herd genetic evaluation of beef cattle for weaning weight has been developed. All known additive genetic relationships among the animals are taken into account. The model includes herd-year means, direct additive genetic values, maternal additive genetic values, and random environmental errors. The procedure obtains best linear unbiased predictors of the genetic values and best linear unbiased estimators of the herd-year means. The procedure takes advantage of opportunities for reducing the number of predictions of genetic values. The model can also be applied in such a way that the resulting predictors and estimators do not have minimum variance, however, the number of genetic equations is further reduced. An example is given. The example gives the impression that further reducing the number of genetic equations increases the prediction error variance of the predictors and the variance of the estimators very little. The example also gives the impression that biases that could result from further reducing number of genetic equations are small. Copyright © 1979. American Society of Animal Science . Copyright 1979 by American Society of Animal Science.