INTERAÇÃO GENOTIPO-AMBIENTE PARA A IDADE AO PRIMEIRO PARTO EM BÚFALAS

Abstract

Given the great importance of environment genotype interaction in a genetic evaluation program, this work was developed to investigate the effects of this phenomenon on the estimates of genetic parameters of age at first birth in the buffalo (Bubalus bubalis) species. Information from animals raised in 12 Brazilian properties was used, and two approaches were defined: a) standard animal model and; b) reaction norms model, with two different definitions of environmental gradient. To estimate the parameters, Bayesian inference was used. The heritability estimate for age at first birth using the standard animal model was 0.196. For the GAIPP approach, heritability estimates ranged from 0.178 to 0.364. Considering the GAPL270 approach, the values ranged from 0.131 to 0.394. Regarding the genetic correlations between different environments, it was found that the definition of the environmental gradient had the greatest influence on the estimates so that extreme values of -0.003 and 0.394 were obtained for GAPL270 and GAIPP, respectively.