Application of genomic information in a dairy cattle breeding scheme

Marker assisted selection has been applied in dairy cattle breeding schemes over the last decade with minor to moderate improvements in genetic gain. In most cases, the cost effectiveness of marker assisted selection has been neutral, at best. The completion of the sequencing of the bovine genome in 2006 has generated a large number of single nucleotide polymorphisms that has allowed the application of genomic selection. In addition, the cost of genotyping single nucleotide polymorphisms is considerably lower than microsatellite genotyping. Livestock Improvement Corporation has undertaken extensive genotyping of the sires that have been progeny tested in the last 20 to 30 years. Analysis of these data by Livestock Improvement Corporation researchers has identified combinations of markers that were used to obtain genetic evaluation of bulls from their DNA. By utilising this genomic information, semen from two-year-old sires has been sold to New Zealand dairy farmers. Over the past two years, the genomically selected bulls have accounted for approximately 15 to 20% of the inseminations. It is expected that selection based on genomic information, termed genomic selection, will increase the rate of genetic gain in New Zealand by 30 to 50%.