Accuracy of Genomic Selection for Growth Traits in Nellore Cattle

Abstract Text: The objective of this study was to evaluate the accuracy of prediction of genomic breeding values using GBLUP method for genomic selection of weight gain from birth to weaning (GBW) and from weaning to yearling (GWY) in Nellore cattle. The accuracy of genomic prediction was evaluated by the correlation (CORR) between EBVs and predicted direct genomic values (DGVs) for animals in the validation group. The regression coefficient of the regression of EBVs on the DGVs (b) was calculated to evaluate the degree of inflation/deflation of genomic predictions. Low accuracies of genomic predictions (0.21) for the both traits, with highly inflated DGVs (b = 0.25 and 0.38 for GBW and GWY, respectively) were found. The results suggest the need for further studies using alternate prediction methods in genomic analysis and possibly the need for a larger training population for obtaining more accurate genomic predictions.

Keywords: beef cattle, Nellore, weight gain