A SIMPLE PROCEDURE FOR OBTAINING APPROXIMATE INTERIM COW SOLUTIONS FROM AN ANIMAL-MODEL

The computational costs required for solving the equations for an indi vidual animal mixed model can be considerable. More frequent evaluatio ns would benefit dairy producers, allowing them to make breeding and m anagement decisions earlier. A procedure was developed to immediately obtain approximate estimates of cow breeding value as soon as new info rmation becomes available. Only solutions for cows with records in pro gress are updated. The algorithm is based on solving a system of two e quations and can be applied by producers. The method corrects for chan ges in estimated production of the current record of a cow but assumes that the effects of changes in evaluations of other animals related t o this cow on the evaluation of the cow in question are negligible. He rd-year-season effects are not reestimated. The correlations between t he updated cow evaluations based on animal model evaluations computed during May 1992, but using estimated production from November 1992, fo r records in progress and the animal model evaluations from November w ere .027 to .064 higher than the correlations between the May and Nove mber evaluations for production of milk, fat, and protein. Although ga ins are slight, the cost application of the algorithm is insignificant .