Abstract #M12

# M12
Genomic testing of female Holsteins: A resource for selection and improvement.
Kimberly M. Davenport*1, Joshua J. Peak1, Brenda M. Murdoch1, 1University of Idaho, Moscow, ID.

Genomic testing is providing a powerful tool for use in dairy management decisions across the United States. While genetic testing has been more broadly implemented for sire selection, its use in selection of females is only now being applied. The identification of females with the most promising genetic potential can influence selection decisions including replacement heifers and cull cows, as well as identify female candidates for embryo donations. Identifying the genetic potential in both male and female contributors to the herd will accelerate genetic improvement and identify potential problems of disease carrier matings before they occur. The purpose of this study was to (1) confirm pedigree information with genetic parentage, (2) identify females that may carry a disease-associated allele, and (3) compare recorded herd data of cows that have been phenotypically selected for reproduction performance to genomic predictions of the Clarifide test. Purebred Holstein cows (n = 162) were sampled by ear punch. Tissue samples were sent to Zoetis and a low density Clarifide genomic test was used to correct pedigree parentage and evaluate the genomes for several markers associated with common selection parameters. Several traits economically important to dairy herds such as milk yield, milk fat component percentage, and traits related to reproductive efficiency and productive life, were compared with results from the Clarifide genomic tests for each animal. The accuracy of parentage records utilizing the parentage correction tool was used to eliminate animal misidentification. The relative similarity of the genomic prediction to phenotypic data and parentage corrections for these traits suggest all be incorporated into future management decisions to accelerate genetic progress of the herd. The sustainability of the US dairy industry will become more dependent upon the effective implementation and strategic use of genomic selection of desirable complex phenotypic traits.

Key Words: genetics, dairy, selection