University of Maryland Extension

Genomic testing helps define management strategies for farmers

Holsteins at the Central Maryland Research and Education Center
Image Credit: 
Edwin Remsberg Photography

The University of Maryland Department of Animal and Avian Sciences hosted a Dairy Field Day and Tour for local farmers on Oct. 10 at the Central Maryland Research and Education Center (CMREC) to discuss results of genomic testing in the University's dairy herd.

A genetic audit of 70 CMREC heifers used biological samples from Zoetis, a global animal health company, to capture data for a host of physical and health-related characteristics, as well as parentage.

"Those traits have an impact on economics," said Victoria Baker, regional representative for Zoetis who presented on the herd results during the Field Day. "Having the right cows in those stalls can hopefully make you profitable."

Zoetis has completed genomics on over 500,000 Holstein heifers across the country and determined genetic markers for a host of traits including health and proclivity to disease, milk production, and even physical characteristics desirable in show animals, said Baker.

Breeding using genetics is not a new practice - farmers and ranchers have historically planned reproduction strategies based on those same traits, breeding their healthiest and best-producing heifers to procure productive offspring, said Baker. Identifying those traits through genomics allows farmers to make those decisions with a higher probability of success, and helps them identify animals that may have health problems in the future.

"[Genomics] help you make decisions to best manage your herd," Baker said.

The audit of the University cattle by Zoetis was performed before the animals' first lactation, and generated data to analyze milk production, breeding, fat yield, and various genetic health traits including mastitis, lameness, and respiratory problems.

While a genetic audit can assist farmers in developing management strategies for a more profitable herd, genetics are a constant that farmers are unable to change or control, said Dr. Li Ma, Assistant Professor in the Department of Animal and Avian Sciences. Developing a healthy environment is the other half of the equation, and has many factors including living conditions, climate, and nutrition.

"The environment is something that farmers can change," said Ma.

Populations of Holsteins across the U.S have shown improvement over the last 60 years, said Ma, due in part to better environmental management and improvement in genetic selection capabilities. "Genetic gains are cumulative," he said.

There is no threshold for improvement in genetic potential, said Baker, but gathering genetic data on more populations locally will provide better efficiency in breeding strategies and allow farmers to make better predictions with higher accuracy, helping them to design a strategy for economically sound management.

The Dairy Field Day was sponsored by Kathy L. Johnson, Agricultural Development Manager, Howard County Economic Development Authority; Bob Enfield, Southern States Frederick Cooperative; Paul Goeringer, Agriculture Law Educational Initiative; and David Whitlock, Select Sire Power. For more information on the CMREC herd or the genomics program at UMD, contact Rachael Slattery at or go to

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