A new study has found that cows given health food, such as flaxseed, produce healthier milk that contains omega-3 fatty acids and less saturated fat.
Studies have shown that 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.
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, according to Gerd Bobe, the lead scientist on the study.
Ten pregnant cows at OSU's dairy were fed different amounts of flaxseed - up to seven percent of their daily diet. Researchers attempted to pinpoint the amount of flaxseed that would maximize the amount of omega-3 in milk and dairy products without negatively affecting their production and texture.
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.
The study found that feeding cows up to six pounds of extruded flaxseed improved the fat profile without negatively affecting the production and texture of the milk and other dairy products. Extrusion presses raw ground flaxseed into pellets with heat.
At six pounds 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. Similar improvements were observed in butter and cheese.
Still, saturated fat accounted for more than half of the fatty acids in the dairy products while the increase in polyunsaturated fats compromised no more than nearly nine percent of the total.
Researchers also noted that the refrigerated butter was softer and less adhesive thanks to fewer saturated fatty acids. Also, the cows produced the same amount of milk while eating flaxseed.
Although flaxseed costs more than traditional cattle feeds, Bobe hopes that 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.
The study has been published online in the Journal of Dairy Science.