Department of Plant and Soil Science
What if Cows and Milk Could Be Healthier?
New Feed Crop Could Create Enriched Dairy Foods
- By Cheryl Dorschner
Grocery shoppers are familiar with eggs fortified with omega-3 fatty acids, but a new study could lead to other products in the dairy case containing these nutrients. Jana Kraft studies whether cattle feed that is high in healthful fatty acids improves cow’s health and the health attributes of milk fat. Her ultimate goal: to create milk, cheese and yogurt that are high in omega-3 fatty acids and selenium.
Because omega-3 fatty acids and selenium have been recognized as nutrients of high biological value that impart health benefits, they represent promising functional food components enriched in milk and dairy products. Diets rich in these nutrients have been shown to be significant in lowering cholesterol and the risk of heart attacks.
“There is growing interest in the development of functional milk and dairy products to maximize their contribution to health promotion and disease prevention,” says Kraft.
Her two-year project began in October 2011, funded by $150,000 from UVM’s Dairy Center of Excellence. “For the current project, the plants for the oil to feed the cows were grown in Canada,” Kraft explains. “However, I’d like to see the plants grown in Vermont to encourage sustainable agriculture here.” To incorporate the bonus of locally grown cattle feed part of the project, Kraft will ask grant funders to extend the project an additional year.
She’s supplemented her initial project with a $60,000 three-year Hatch Project ending in 2015 to test her hypothesis on an animal model and additionally “look at the cow level, that is, the objective is to improve the overall health of the cow through feeding omega-3 fatty acids,” she says.
NOT SO SIMPLE, BUT WORTH IT
Why not just add omega-3 fatty acids to milk and yogurt and skip running it through the cow altogether?
“The omega-3 fatty acids could be simply incorporated into the products,” Kraft concedes, “but one of our major goals is also to improve the cow's health, so with one strategy we will accomplish two goals: improving the healthfulness of milk and enhancing the health of the dairy cow.” Then there’s the suspended fat. “If you add fats to dairy products, you will need to emulsify it into the product,” she says. “A 'naturally enriched' product may be more appealing to or accepted by the consumer.” Last but not least, there are a number of reasons having to do with milk chemistry. “Milk fats' composition is unique, for example, the milk fat globule membrane contains bioactive substances by itself. Milk fat is easy to digest and has a unique and desirable texture and flavor,” Kraft explains. “By simply adding the omega-3 fatty acids and/or removing milk fat, you may alter the typical and desirable flavor and texture of milk and the way it performs in recipes.”
Unfortunately, one can’t just feed cattle, say, fish oil, which is rich in omega-3 fatty acids, because the oil is toxic to the bacteria in the rumen that digest the feed in the cattle’s stomach, Kraft explains. Also, the rumen bacteria convert unsaturated fatty acids to saturated fatty acids – the opposite of our goal of adding healthful fatty acids to the diets of both cows and humans.
One “work-around” this obstacle is to add encapsulated rumen-protected oil to the feed. But ultimately, Kraft believes she will come up with a novel rumen-protected, feed source that is high in specific omega-3 fatty acids, will be good for cows that eat it and the beneficial acids will be present in their milk. To that end, she analyzes the milk for lipids and fatty acid analysis using gas chromatography to test variables such as what feed offers the highest levels of omega 3’s and what is the lowest dose cattle must receive for the benefits to show.
In related research, Kraft recently submitted a proposal to the New England Dairy Promotion Board/Vermont Dairy Promotion Council to collaborate with UVM College of Medicine to improve understanding of the role of milk fat from whole milk as an integral part of a balanced diet and its efficacy in modulating risk factors associated with metabolic syndrome. This study will be a human intervention trial.
Kraft feels that “milk fat is getting a bad rap. Milk fat contains a unique variety of bioactive fatty acids that may account for beneficial effects of milk fat. Whole-milk dairy products are an important part of a healthful diet. Balance is what is important,” she says.
“Many researchers focus on developing new products for the market, but overlook human nutrition as a component of those products,” says Kraft, who is an assistant professor of animal science. “My work is the interface between animal science and human nutrition.”
“Dr. Kraft’s research is innovative and timely with its focus on making dairy foods even more healthful in a natural way, and it fits with the multi-disciplinary expertise of the department in that it looks to improve both animal and human health,” says André-Denis Wright chair of animal science in UVM’s College of Agriculture and Life Sciences.