Ohio State University scientists have found a new way to produce more nutritious milk: Feed dairy cows flaxseed.

Cows who received flaxseed as part of their regular feed produced milk with more heart-healthy omega-3 fatty acids and less saturated fat, which can increase cholesterol and cause cardiovascular disease, the researchers reported in a study published online in the Journal of Dairy Science.

Diets high in saturated fat can increase cholesterol and cause heart disease, while those rich in omega-3 and other polyunsaturated fatty acids may reduce the risk of heart disease, studies have shown.

Lead researcher Gerd Bobe noted traditional cattle feed mixtures of corn, grains, alfalfa hay, and grass result in dairy products with low concentrations of omega-3s and other polyunsaturated fats.

Bobe and colleagues fed 10 cows at OSU's dairy different amounts of the seeds — up to seven percent of their daily diet — to determine how flaxseed that would maximize the amount of omega-3 in milk and dairy products without affecting their production and texture.

"We were looking for a sweet spot," said Bobe, an expert in human and animal nutrition. "Too much of a good thing can be bad, especially when trying to maintain consistency with dairy products."

Collaborators in OSU's food science and technology department also turned milk into butter and fresh cheese from the cows’ milk.

The results showed feeding cows up to six pounds of extruded flaxseed — raw ground seeds pressed into pellets — reduced saturated fatty acids in whole milk fat 18 percent, while poly-unsaturated fatty acids increased 82 percent, and omega-3 levels rose 70 percent.

Similar improvements were noted in butter and cheese.

Although flaxseed costs more than traditional cattle feeds, Bobe said it still could be an affordable feed supplement for cows because products enriched with omega-3 can sell for a premium at the grocery store.

"Many consumers already show a willingness to pay extra for value-added foods, like omega-3 enriched milk," he said.

He added that the OSU experiments showed dairy farmers would have no trouble convincing cows to eat flaxseed. "They loved it. They ate it like candy," he said.