DNA testing is tool to fine-tune genetic evaluationsd


Cattlemen have come to believe DNA testing will make genetic selection simpler; whereas, it will actually make it more complicated, but more effective, said Mark Thallman of the U.S. Meat Animal Research Center (MARC) at Clay Center, Neb.
The belief that DNA testing will completely replace expected progeny differences (EPDs) for making genetic selection is a myth, said Mark Thallman of the U.S. Meat Animal Research Center (MARC), Clay Center, Neb., during the opening session of the 2004 Beef Improvement Federation (BIF) Annual Meeting in Sioux Falls, S.D., May 25. However, DNA technology does offer opportunity to add accuracy to current evaluation systems.

“DNA testing has been oversold for a long time,” Thallman said. “I think we’re getting better about it now, but originally there was a lot of discussion that DNA testing was just going to replace the need for reporting of pedigrees and phenotypes.”

The current system of genetic evaluation ties pedigree and phenotype, or performance, information on a number of animals together through the process of National Cattle Evaluation (NCE) to provide EPDs. Thallman said incorporating DNA test results into that system to provide marker-adjusted EPDs will provide more accurate evaluation of genetic potential, especially for cattle at an early age.

Thallman noted that it will be difficult to include DNA test results into the NCE until sufficient data has been collected. Ironically, cattlemen tend not to collect a lot of data until it can go into NCE.

He encouraged breed associations to develop procedures for direct acquisition of DNA test results into breed databases.

“Breed associations can play and important role in encouraging the flow of DNA testing information into NCE and reporting the resulting DNA-adjusted EPDs back to the breeders,” he said. “They will need to provide education on how to use this technology effectively and on how not to misuse it.”

– by Shauna Rose Hermel