Breeding and Genetics Symposium I: How genomic selection has changed livestock breeding
In the past decade, genomic testing of beef cattle has evolved from applications in research, to a routine practice for many beef cattle seedstock breeders. Testing for lethal genetic conditions or parentage was many breeders’ first experience with genomic testing. While the American Angus Association (AAA) began utilizing 384 SNP genotypes in genetic evaluations in 2009, the adoption of genotyping with higher density (~50,000 SNP) arrays by AAA in 2010 launched large-scale genotyping of Angus cattle for genetic evaluation. AAA transitioned from semi-annual to weekly genetic evaluations in 2010, and cost of genotyping decreased from $139 per animal in 2011, to $37 in 2017. In fiscal year 2018, AAA members genotyped over 160,000 animals for genetic evaluation, and as of April 2019, the AAA and Canadian Angus Association joint genetic evaluation includes over 635,000 genotyped animals. Now genotyping arrays with Angus-specific SNP content are used. The primary benefit to Angus breeders has been increased accuracy of genetic prediction for young animals, especially for traits with limited phenotypic information such as carcass traits, feed intake and mature cow size. Future benefits from genotyping include identification and selection against embryonic lethal alleles, better characterization of inbreeding, and selection tools for additional traits relevant to or measured in unique environments. Electronic sensors and other novel approaches may yield previously unmeasurable phenotypes for health and efficiency traits, which can be extended to wider populations for selection using genomics. New techniques such as DNA pooling and genotyping by sequencing may reduce costs enabling widespread testing in commercial cow-calf and cattle feeding enterprises. The application of genomic selection has clearly been a significant advancement in genetic selection in Angus cattle in the past ten years. This early adoption will expedite subsequent genomic tools at an increasing rate and will foster innovation.