Location: Genetics and Animal BreedingTitle: Validation of SNP associations with bovine ovulation and twinning rate
Submitted to: Animal Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/4/2019
Publication Date: 5/15/2019
Citation: Kirkpatrick, B.W., Thallman, R.M., Kuehn, L.A. 2019. Validation of SNP associations with bovine ovulation and twinning rate. Animal Genetics. 50:259-261. https://doi.org/10.1111/age.12793.
Interpretive Summary: Previous work identified genetic variants associated with twinning rate in the US Holstein population and developed a model for genomic prediction. The current study was conducted to assess association of these variants with twinning rate and ovulation rate in a genetically diverse beef cattle population selected for twinning and ovulation rate. Of 14 variants assessed, one had a strong association with twinning rate in the beef cattle population. This variant may be useful to improve the rate of genetic improvement of beef cattle for twinning rate.
Technical Abstract: Previous work identified SNP associations with twinning rate in the US Holstein population and developed a model for genomic prediction. The current study was conducted to assess association of these SNPs with twinning rate and ovulation rate in a genetically diverse, outbred population selected for twinning and ovulation rate. A total of 18 SNPs which were components of a prediction equation for twinning rate in Holstein cattle were genotyped on 731 animals from the USDA Meat Animal Research Center production efficiency or twinning population. These 731 individuals were sires and dams well represented in the pedigrees of animals from the general twinner population, and their genotypes were used in predicting genotypes for animals in the larger population (n=16,035). Twinning rate and ovulation rate were analyzed in a two-trait repeated records analysis with marker associations analyzed individually as fixed effects. Criteria for marker validation were effect estimate with a sign consistent with previous estimates and significance at a nominal P<0.01. Of the 14 SNPs passing quality control assessments, only one was validated. A SNP in the 5' flanking region of the IGF1 gene, discovered previously in a positional candidate gene analysis, was significantly associated with twinning rate in the USDA twinning population (P<0.0002). This SNP may have utility in genomic prediction of twinning rate beyond the Holstein population.