Genotype-environment interaction for growth and reproductive traits in Nellore cattle, using reaction norms

Abstract Text: The aim of this study was to verify the importance of genotype-environment interaction (GEI) for age at first calving (AFC), scrotal circumference (SC) and yearling weight (YW) in Nellore cattle, using reaction norms in multi-trait random regression models. The heritability estimates for all traits increased as the environment became more favorable and ranged from low to medium for AFC , high for SC and medium to high for YW. The genetic correlation estimates between AFC and SC, AFC and YW, YW and SC in different environments, ranged from -0.15 to -0.68, -0.18 to -0.35, -0.1 to +0.68, respectively. There is an important GEI effect for AFC, SC and YW traits, so the expected genetic gain for these traits depend on the environment in which the animals are exploited.

Keywords:

Age at first calving

Genetic correlation

Nellore

Scrotal circumference

Yearling weight