New technology speeds dairy marker application for Australian farmers

Australian dairy farmers are one step closer to accessing genetic markers for identification of desired traits in their cows and speeding genetic gain of the dairy herd, thanks to a collaborative agreement between the Dairy Cooperative Research Centre (CRC) and ParAllele BioScience, a United States biotech company that was recently acquired by Affymetrix Inc. (Nasdaq: AFFX), to screen the DNA of more than 1500 elite Australian dairy bulls.

The technology from ParAllele will enable researchers to screen the DNA of individual sires bred and performance-tested for Australian conditions using stored semen supplied by Genetics Australia. Patterns observed in the bulls’ DNA, known as genetic markers, can be correlated with particular performance traits and be used to directly identify elite cattle.

Through the national database of the Australian Dairy Herd Improvement Scheme (ADHIS), information is available on the performance and pedigree for each screened bull.

“The Dairy CRC will combine the DNA data generated by the ParAllele technology with the information in the ADHIS database to produce a very clear indication of which genetic markers correlate to specific traits found in individual animals – a unique and exciting development made possible through the application of new genetic technology to Australian dairy semen resources,” said Professor Herman Raadsma from the University of Sydney’s Faculty of Veterinary Science and leader of the CRC’s Gene Discovery Program which also includes the search for genetic markers.

Dairy CRC researchers are investigating a range of markers for traits in the dairy cow which are of value to farmers. When markers identified by researchers are linked with particular performance traits, bull calves can be tested for the presence of these markers. This information could predict their sire performance, which could greatly improve sire selection for progeny testing.

Dairy farmers will be able to send off a sample of a cow’s hair to a laboratory to determine if she has the markers for particular traits. Farmers will then be able to use that information in breeding and herd management decision-making.

“DNA testing for markers will identify if animals are likely to have genes that, for instance, predispose a cow to persist in her lactations, produce higher-quality milk or be more resistant to diseases such as mastitis,” said Dr Paul Donnelly, Chief Executive Officer of the Dairy CRC.

“A group of markers taken together may even predict Australian Profit Ranking (APR).”

The ParAllele technology works in conjunction with the Affymetrix GeneChip^® technology, enabling researchers to study an animal’s entire genome (the complete set of genes) to identify the handful of genes associated with the desired traits of the elite cattle. This high-density genome-wide scan will fast track the application of genetic markers of particular interest to Australian dairy farmers, which will help increase profits.