Approximate accuracies of prediction from random regression models

A procedure for obtaining approximate reliabilities of estimated breeding values under a random regression model is presented. The method is based on a concept of an equivalent number of progeny, with subsequent selection index approximation of reliability utilising equivalent progeny information on the animal and its parents. The accuracy of the proposed approximation was tested using st multiple trait random regression test day model for dairy production traits applied to Canadian Jersey data. Gibbs sampling method was used to generate exact reliabilities of genetic evaluations for several traits derived from the genetic random regression coefficients. The approximation was shown to be relatively unbiased for both bulls and cows. The method has been implemented in the Canadian test day model for dairy production traits. (C) 2000 Elsevier Science B.V. All rights reserved.