Abstract:

The objective of this study was to evaluate the gain in accuracy of genomic predictions by adding selected sequence variants to a high-density SNP panel and using weighted or regular single-step GBLUP (ssGBLUP) for age at first calving evaluations in Nellore cattle. Phenotypic records from 224,110 heifers from the Alliance Nellore database and 42,788 genotyped animals were used. All genotyped animals were imputed to whole-genome sequence based on a reference of 151 Nellore sires. A whole-genome association was performed, and 403 sequence variants were selected for inclusion in the high-density SNP panel. Accounting for sequence variants in ssGBLUP did not increase prediction accuracies and only marginally increased accuracy (1%) in weighted ssGBLUP. Our study indicates that genomic selection with ssGBLUP helps to improve prediction accuracy for age at first calving; however, only a marginal gain is observed by including selected sequence variants in the ssGBLUP.