Genotype by environment interaction in Nelore cattle from five Brazilian states

Abstract

Records from 75,941 Nelore cattle were used to determine the importance of genotype by environment interaction (GEI) in five Brazilian states. (Co)variance components were estimated by single-trait analysis (with yearling weight, W450, considered to be the same trait in all states) and multiple-trait analysis (with the record from each state considered to be a different trait). The direct heritability estimates for yearling weight were 0.51, 0.39, 0.44, 0.37 and 0.41 in the states of Goiás, Mato Grosso, São Paulo, Mato Grosso do Sul and Minas Gerais, respectively. The across-state genetic correlation estimates between Goiás and Mato Grosso, Goiás and Minas Gerais, São Paulo and Minas Gerais, and Mato Grosso do Sul and Minas Gerais ranged from 0.67 to 0.75. These estimates indicate that GEIs are biologically important. No interactions were observed between Goiás and São Paulo, Goiás and Mato Grosso do Sul, Mato Grosso and São Paulo, Mato Grosso and Mato Grosso do Sul, Mato Grosso and Minas Gerais, or São Paulo and Mato Grosso do Sul (0.82 to 0.97). Comparison of single and multiple-trait analyses showed that selection based on the former was less efficient in the presence of GEI, with substantial losses (up to 10%) during selection.

Genotype by environment interaction for birth and weaning weights of composite beef cattle in different regions of Brazil

“…These authors state that each biological trait should be treated as a different trait in each of the states for the identification of superior individuals. Diaz et al (2011), in a study with yearling weight of Nellore in five Brazilian states, reported genetic correlations of about 0.7 between some states. Posterior densities for the estimates of genetic correlations obtained by these authors reached values close to 0.4, showing the importance of G Â E. Due to low genetic correlations, Bertrand et al (1985) suggested that the genetic evaluation of Polled Hereford bulls in some regions of the United States should be evaluated separately.…”

Genotype by environment interaction in different birth seasons for weight at 240, 365 and 450 days of age in Tabapuã cattle

“…Selection of more animals in the season that have higher residual variance is not desirable, since in a practical manner, animals from seasons with less "controlled" environments could be chosen (Diaz et al, 2011b).…”

“…However, the GEI effect was noticed to be important for the country and even among regions (Diaz et al, 2011a(Diaz et al, , 2011b. Taking into account that Brazil is a country in which it is possible to observe distinct types of environments with heterogeneous systems of cattle raising (Lopes et al, 2008), the presence and the importance of GEI evaluation seems to be justified.…”

Cluster and meta‐analyses of genetic parameters for feed intake traits in growing beef cattle

“…The observed difference found in this study between weights of males and females is consistent with other studies involving various beef cattle breeds (Diaz et al . ; Pégolo et al . ).…”