Genotype by environment interaction on crossbreed beef cattle

[摘要] Data from Hereford and Nelore breeds and their crosses were used to estimate the effect of genotype and environment interaction on weaning and yearling weights. The statistical analyses were performed by the least-squares method using models that included region, contemporary group within region, month of birth and sex of the calf, linear and quadratic effects of age of the calf and age of the cow, both nested within sex, and the genetic group and genetic group × region interaction effects. In general, genetic groups were influenced by the region effect. Differences in performance between regions decreased as the proportional contribution of zebu increased. All genotypes increased performance in the less restrictive environment. Crossbreeding systems should consider keeping fitness of dams and their products to environmental conditions.

[学科分类] 兽医学

[关键词] genetic group;heterosis;yearling;weaning    Introdução Uma das alternativas para melhorar os índices de produção da pecuária é a utilização de sistemas de cruzamento entre raças;pois;ao combinar cruzamentos e seleção;é possível adequar mais rapidamente o genótipo dos animais para que tenham bons desempenhos produtivo e reprodutivo nos mais diversos ambientes