Genotype x environment interaction for milk yield in buffaloes.

Abstract Text:

The milk yield at 270 days (MY270) of 1,004 first lactations of Murrah Buffaloes was analyzed. For MY270 analysis, a random regression (RRM) uni-trait model was performed. In the reaction norm model, the variance components were regressed on the environmental gradient (EG). In RRM linear Legendre polynomials were used, regressed on MY270 average adjusted for each EG. The attainment of the covariance components was performed by Bayesian inference. Estimates of additive genetic, phenotypic and residual variance ranged from 36,562 to 100,426 (kg²), 96,116 to 245,094 (kg²) and from 59,553 to 144,667 (kg²), respectively. The heritabilities ranged from 0.20 to 0.41. The genetic correlations between different EGs were higher as EGs were closer or similar. Based on the criteria used to define the EG, it can be noted the presence of genotype-environment interaction for MY270.

Keywords:

dairy cattle

breeding

bayesian inference