Genome-wide association of age at first calving in Nelore cattle using phenotypes from genotyped and ungenotyped animals

Abstract Text: The goal of this study was to perform  genome-wide association (GWA) analyses of age at first calving in Nelore cattle using the  weighted single step GBLUP method under two scenarios, including (n=43,482) or not (n=1,813) the phenotypic information from ungenotyped animals, and to compare the most important genomic regions identified in both scenarios. For each scenario, three different weightings were tested, with increasing shrinkage for SNPs explaining lower variance. The GWA analyses considered 333,878 SNPs distributed along the autosomes. Additional phenotypic information from ungenotyped animals influenced the results of GWA analyses, especially when higher shrinkage was applied to SNPs explaining lower variance. Besides some coincidence, the most important genomic regions indicated by the analyses considering or ignoring phenotypes from ungenotyped animals were not the same.

Keywords:

complex traits

sexual precocity

single step GBLUP