Prediction of GEBV in comparison with GMACE value of genotyped young foreign bulls

Abstract

EBVs and GEBVs for milk yield of young genotyped Holstein bulls were predicted using a conventional Animal Model, RRBLUP, GBLUP, ssGBLUP and one-step blending procedures. For prediction, the nation-wide databases of domestic Czech production records from the first lactation combined with deregressed proofs from Interbull files through 2013, which had been transformed by MACE to domestic production conditions, and domestic test-day-records in the first three lactations were used. 2,627 genotyped bulls were used, from them 2,189 already proven in domestic condition. Analyses were run that used Interbull values only for these genotyped bulls, or used Interbull values for all available sires. Predictions were compared with GEBV of 96 young foreign bulls evaluated abroad and transformed by Interbull method GMACE 09/2013 into Czech scale. Correlation of predictions with GMACE value of foreign bulls ranged from 0.33 to 0.75. Combining domestic data with Interbull EBVs improved prediction of both EBV and GEBV. Prediction by Animal Model (traditional EBV) using only the domestic first lactation had correlation with GMACE value 0.33; whereas combining the nation-wide domestic database with all available deregressed proofs for genotyped and non-genotyped sires from Interbull resulted in of EBV correlation 0.60, compared to correlation 0.47 when using Interbull data only. Genomic enhanced breeding value has in all cases higher correlations than traditional EBV, the highest correlation were for predictions from the ssGBLUP procedure using combined data (0.75). ssGBLUP with domestic three lactations test-day-records has correlation with GMACE 0.69.