This study wascarried out to evaluate some alternatives for modeling of genetic and environmentaleffects influencing the weaning weight of Charolais-Zebu crossbred calves. Theweaning weight data of 56,965 calves with alleles' percentage from the Charolaisbreed varying from 23% to 66% were used. The models under comparison differedfor the inclusion of the individual and maternal additive and non-additive geneticeffects, as well as the way to model those effects (multiple regression or discretevariable). The inclusion of the interaction between the calf genetic group andits contemporary group was also evaluated as a random uncorrelated effect. Theadjustment criteria pointed out the interaction between the calf genetic groupand its contemporary group to represent a significant part of the variationobserved for the weaning weight of the Charolais-Zebu crossbred calves, andthe effects of alleles' percentage from the Charolais breed and the heterozygosity,individual and maternal, can be modeled by using the multiple regression.
