Grazing Cows Produce More
Cancer-Fighting Compound in Milk
By Linda McGraw
April 7, 2000
A change in the way U.S. dairy cows are
fed may give consumers one more healthful reason for drinking milk. Cows
grazing pastures, or fed diets containing vegetable oil, produced five times
more of a cancer-fighting compound--conjugated linoleic acid (CLA)-- than cows
fed conventional diets, according to Agricultural Research Service studies in
CLA is a fatty acid found in beef and dairy fats. The human body
doesnt produce CLA on its own, but CLA is available through foods such as
whole milk, butter, beef and lamb.
ARS dairy scientist Larry Satter at the ARS
U.S. Dairy Forage Research Center
showed how to increase CLA levels in milk from cows fed typical confinement
rations. He added whole soybean and linseed oils to a typical corn-alfalfa
diet, boosting the CLA content in the cows milk to equal the levels
obtained from grazing. ARS and the
Wisconsin Alumni Research
Foundation (WARF) patented this method to increase CLA in cows milk.
These studies may increase interest in grazing for dairy cows. Currently,
only 10 to 12 percent of U.S. dairy cows are grazed, according to Satter.
A University of Wisconsin researcher is
credited with discovering CLAs cancer-fighting properties in a study of
rats fed fried hamburger. Today, human studies of CLA are underway at several
research institutions. Laboratory animals given CLA in their diets have shown a
reduction in several types of cancers and a slower progression of
atherosclerosis, a contributor to heart disease.
If human trials show the same benefits as studies with laboratory animals,
the benefit of consuming milk products could impact the economy of dairy
ARS is the U.S. Department of
Agricultures chief research agency. The research is featured in the
April issue of Agricultural
Scientific contact: Larry Satter, ARS
U.S. Dairy Forage Research Center, Madison, Wis., phone (608) 264-5353, fax
(608) 264-5147, email@example.com.