Genotype x Environment Interaction for reproductive traits in brazilian Nellore breed cattle

Abstract

SUMMARY The objective of this study was to evaluate the effect of the genotype-environment interaction (GEI) for scrotal circumference traits measured at different ages, 365 (SC365), 450 (SC450) and 550 (SC550) days of age, and age at first calving (AFC) for Nellore animals raised in different regions of Brazil. For the evaluation, the herds were grouped in the following regions of the country: North, Southeast and Central-west, using information from 26,619, 28,730, 14,476, 15,397 for the traits SC365, SC450, SC550 and AFC respectively. Genetic parameters, as well as the assessment of GEI were performed using Bayesian inference, using the programs of the BLUPF90. The estimated heritabilities were: 0.465 ± 0.021, 0.500 ± 0.022, 0.492 ± 0.026, 0.117 ± 0.017 for SC365, SC450, SC550 and AFC respectively. The results obtained in the analysis, indicated that this interaction was not significant for SC at different ages (genetic correlation, rg> 0.8). For AFC, significant effect of GEI was observed for combinations involving the Northern region (rg<0.8), indicating that this interaction should be considered by the genetic evaluation programs in this region.

Heteroscedastic Reaction Norm Models Improve the Assessment of Genotype by Environment Interaction for Growth, Reproductive, and Visual Score Traits in Nellore Cattle

“…The effect of genotype by environment interaction (GxE) has received special attention from several studies regarding its effect on traits related to growth, reproduction, and health [ 6 , 7 , 8 , 9 , 10 ]. These authors have pointed out the re-ranking of animals as the main interaction effect of GxE in tropical production systems for traits with economic importance in breeding programs.…”