Emerging Technologies
Implementation of Genomic Evaluation in the Dairy Industry
Abstract:
Genomic evaluation and selection refer to the use of a panel of genetic markers densely covering the whole genome to estimate the breeding value or progeny difference of animals. Genomic evaluation is most advanced in the dairy industry and in particular in the USA, but all major dairying countries are now implementing it. This requires a reference population that has been recorded for the important traits and genotyped for the markers. In dairy cattle this usually consists of progeny-tested bulls, but in future it also will contain cows.
The reference population is used to estimate a prediction equation, which predicts breeding value from marker genotypes. This prediction equation can then be applied to bulls and heifers that do not have records for the traits or progeny but do have marker genotypes. As the size of the reference population increases, the accuracy of the prediction equation improves, so that it is possible to predict the breeding value of a calf for milk yield almost as accurately using markers as with a progeny test. The accuracy of genomic evaluations is higher in dairy cattle than in beef cattle for several reasons — one major breed, a larger reference population comprised of animals with more accurate evaluations.
In the dairy industry in USA and Australia the marker data is being viewed as just a new source of data to add to the traditional data used to estimate breeding values (performance records and pedigrees) and so the genomic evaluation will become part of the traditional herd recording and genetic evaluation system. This will make genomic EBVs or EPDs easy for dairy farmers to use because there will be only one system within the country, and it will be directly comparable to the traditional EPDs. However, in all cases there is a desire by those who have invested in the reference population to seek to have its use restricted so that they can benefit from their investment. This is reasonable, but I believe that in the longer term an open system that everyone can use will best serve our livestock industries.
About the speaker:
Mike Goddard is a professorial fellow in animal genetics with a joint appointment from the University of Melbourne and Victoria Department of Primary Industries. He graduated in veterinary science (1972) and did a doctorate on breeding guide dogs for the blind (1979) before becoming a lecturer in biometrics at James Cook University, Townsville (1977-1983), and then a scientist in the Department of Agriculture (1983-1993) and director of the Animal Genetics and Breeding Unit (1993-1998).
Goddard’s research on genetic improvement of dairy and beef cattle and pigs and application of genomics to genetic improvement has broad application and global recognition. In 2001, he published the first paper on genomic selection. It showed how to use dense SNPs covering the whole genome to accurately estimate the genetic merit of animals.
Currently, he serves as the chief scientist of the Cooperative Research Center (CRC) for Beef Genetic Technologies in Australia. This CRC is using the human, mouse and bovine genomes to improve the profitability and productivity of Australian and global beef businesses. It is one of 49 CRCs funded by the Australian Commonwealth Government.
BIF acknowledges the support of the National Research Initiative Grant no. 2009-55205-05062 from the USDA Cooperative State Research, Education and Extension Service Animal Genome program for sponsoring Goddard’s attendance at this meeting.
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