IMPLEMENTATION OF SINGLE-TRAIT AND MULTIPLE-TRAIT ANIMAL-MODELS FOR GENETIC EVALUATION OF HOLSTEIN TYPE TRAITS

Animal model genetic evaluations for final score and 14 linear type tr aits were implemented for US Holsteins in July 1991 and July 1992, res pectively. Data included 5.19 million records on 2.83 million cows for final score and 3.52 million records on 2.05 million cows for 14 line ar traits. The model included effects of herd-year-month of classifica tion, herd by sire interaction, permanent environment, and animal with unknown-parent groups. A multiple-trait procedure for the linear trai ts was facilitated by a canonical transformation in which the (co)vari ance matrix for the herd by sire and permanent environment effects wer e assumed to be proportional to that of the residual effect. Memory re quirements were reduced by ordering the data by herds because over 87% of the effects were nested within herds. Investigation of three diffe rent computing platforms identified a Unix workstation as the best com puting environment. Correlations between the sire and animal model bre eding values for bulls with semen available in 1992 were .92 for final score and .91 to .96 for the linear traits. Genetic merit of the mate s was accounted for more completely by the animal model, resulting in important differences in breeding value predictions between the two mo dels.