Flaxseed Diet Leads to Healthier Milk From Cows

More nutritious milk with much more omega-3 fatty acids and less saturated fat is delivered by dairy cows that are fed flaxseed, according to a new study by Oregon State University.

Goal of the study was to find the ideal amount of flaxseed in cows diets to maximize the omega-3 content in the resulting dairy products, while still achieving high standards of production quantity and texture of those. The results are promising, at six pounds flaxseed fed per day, saturated fatty acids in whole milk fat dropped 18 percent, poly-unsaturated fatty acids increased 82 percent, and omega-3 levels rose 70 percent compared to feeding no flaxseed.

Milk produced in this way could represent a convenient adjustment, at little cost, to the everyday diets of billions of people. Studies have shown that eating a lot of saturated fat can increase cholesterol and cause heart disease, while eating omega-3 and other polyunsaturated fatty acids may reduce the risk of heart disease.

Traditional cattle feed mixtures of corn, grains, alfalfa hay and grass silage result in dairy products with low concentrations of omega-3 and other polyunsaturated fats, on the other hand, flaxseed costs more than those. Gerd Bobe, lead scientist on the study, which has been published online in the Journal of Dairy Science, suggests that it still could be an affordable feed supplement for cows since products enriched with omega-3 are worth more, while the production cost increase of single cents per gallon would be quite marginal compared to the possible premiums.

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

Conducting the research, ten pregnant cows at OSU's dairy were fed different amounts of flaxseed - up to seven percent of their daily diet. Collaborators in OSU's food science and technology department assisted in turning milk into butter and fresh cheese, which were then tested for texture and nutritional composition.

"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."

It should be noted that while the fat profile was significantly adjusted to the better, saturated fat still accounted for more than half of the fatty acids in the dairy products while the increase in polyunsaturated fats compromised nearly nine percent of the total.