|SAVAGE, DOUG - Non ARS Employee|
Submitted to: Holstein International
Publication Type: Popular Publication
Publication Acceptance Date: 7/10/2018
Publication Date: 8/1/2018
Citation: Savage, D. 2018. 10 years of revolution: Paul VanRaden looks at the evolution of genomics. Holstein International. 25(8):16–17.
Technical Abstract: The arrival of genomics 10 years ago has evolved into the biggest revolution the cattle breeding industry has seen. A look back at some of the developments as genomics were implemented is presented. A breakthrough in the speed of genotyping allowed thousands of markers to be tested cheaply and the subsequent development of a genotyping chip with 50,000 single-nucleotide markers. Although data quality was good, thousands of progeny-tested bulls had to be genotyped to prove that genomic selection works. Once genomics was verified to be much more accurate than parent average in predicting genetic merit of the sons of those bulls, artificial-insemination organizations started genotyping young bulls. Initially the main use of the technology was planned for selection of bulls, but then it was realized that the value was even greater for improving accuracy of evaluations for cows. At first, breeders started genotyping their favorite cows but soon discovered it was more important to genotype heifers. The biggest growth area was for large commercial herds, and many now genotype all their heifer calves and use the results for selecting and managing their herds. Over half a million genotypes are added annually to the U.S. database maintained by the Council on Dairy Cattle Breeding (CDCB), and that database now includes information from over 2.1 million Holsteins from the United States, Canada, and 55 other countries. North America has had an edge over other countries because of its aggressive use of genomics to shorten generation interval and identify genetic outliers among progeny. The technology also has led to other uses including pedigree discovery. Whole herds without parentage recording can now have sire, maternal grandsire, and sometimes even maternal great-grandsire determined based on a 3-generation pedigree generated from one test. Dairy-cattle breeding has been a leader in the use of genomics because of the size of the database, but the use of genomic tools for humans and other species is growing. One future growth area for dairy cattle genomics is the genotyping of all cows.