Curtis Van Tassell ’94, Animal Breeding and Genetics

Cows grazing
Photo courtesy of the USDA Animal Genomics and Improvement Laboratory, for which Curtis Van Tassell works

In the last few years, family genealogy research has gotten much easier. With a cheek swab and a hundred dollars or so, you can figure out what part of the world your ancestors came from, and be connected to a third-cousin you never knew you had. A hobby that once involved dusty afternoons in archives has gone digital.

Recognizing that bovine genes could be surveyed in similar ways, Curtis Van Tassell, a researcher at the USDA’s Agricultural Research Service’s Bovine Functional Genomics Laboratory in Beltsville, Maryland, has been instrumental in revolutionizing how we breed dairy cows for better milk production.

Because of the emphasis on productivity in the U.S., farmers are only interested in using the highest-quality bulls for breeding purposes. This means that, through artificial insemination, only a small pool of 500 Holstein bulls fathers the calves of nine million Holstein cows. Previously, these bulls were selected based on their pedigree—if their mothers and sisters were known to be high producers. But these pedigrees were laborious to compile, and only about 30 percent accurate.

By coupling the existing knowledge of bovine genetics with the animals’ backgrounds, Van Tassell was able to identify dozens of genes that correlated to good breeding and high performance. Once these genes were identified, newborn cows and bulls could be tested without having to wait until they reached milk-production age. These tests are up to 70% accurate; twice as good as the pedigree method.

Van Tassell has been recognized with several awards, including the White House Presidential Early Career Award for Scientists and Engineers, the USDA Secretary of Agriculture Honors in Excellence Award, and the American Dairy Science Association 2012 J.L. Lush Award in Animal Breeding. As part of his work, Van Tassell has also created the USDA-BARC Dairy Diversity Panel, which genetically characterizes six different breeds of dairy cattle, and the Cooperative Dairy DNA Repository, which banks genetic material from dairy bulls for research purposes.

While Van Tassell’s research has had far-reaching effects on the dairy industry as a whole, its relevance has also hit closer to home. Van Tassell grew up on a dairy farm in Dutchess County, New York, with his brother, Stephen, who still operates the farm. Since implementing Van Tassell’s genetic tests alongside careful breeding, the farm’s revenue has doubled.