The results of the review are on the Web at www.csuchico.edu/agr/grassfedbeef/ .

The vast majority of U.S. beef cattle eat grain or other high-calorie feed for several months at a feedlot before being processed. Eating such concentrated feed fattens the animals quickly and produces fat-marbled meat that is favored for its flavor and tenderness. Grass-fed cattle live out their lives on the range or pasture eating grass or hay. Their meat is leaner, less tender and contains the higher nutrient levels. It is also a product that can be marketed at a higher price, making grass-feeding a value-added process that can help cattle producers earn more money during difficult economic times.

"Grass-fed hamburger meat sells for about $1 more per pound. Steaks are sold at about double the normal price - about $7 more per pound than ordinary beef," said Glenn Nader, UC Cooperative Extension livestock and natural resources farm advisor in the Sutter-Yuba County office and the leader of the project.

However, because of the higher cost, the market is limited to a certain type of consumer. Grass-fed beef is preferred by people who have avoided meat because they believe grain could be more efficiently used to feed the world's poor, and those that feel purchasing grass-fed beef supports the preservation of open rangelands in rapidly urbanizing communities.

"These products sell in natural food stores that attract high-income, health-conscious consumers," Nader said. "We don't think grass-fed beef is a wave of the future. It represents a small niche market that we're trying to make available to ranchers." 

UC Cooperative Extension and CSU, Chico, received a $14,000 grant from the W. K. Kellogg Foundation California Food and Fiber Future project to study and promote the health benefits of grass-fed beef. Two CSUC students, Amber Abbott and Margaret Basurto, conducted a literature review, in which research results that were reported in 55 articles, letters, Web sites and commentaries by scientists representing a wide variety of institutions were studied, collated and aggregated.

Their report concluded that ranchers who produce grass-fed cattle may rightfully claim the product is more healthful than conventionally produced meat.

The report says that three ounces of ground beef from cattle fed conventional diets contain about 41 micrograms of beta-carotene and a typical rib eye steak has 36 micrograms. In contrast, meat from cattle fattened predominately on ryegrass has almost double the beta-carotene, 87 micrograms in 3.5 ounces of ground beef and 64 micrograms in a steak.

Beta-carotene is converted to vitamin A in the body. While excessive amounts of vitamin A in supplement form can be toxic, the body will only convert as much vitamin A as it needs from beta-carotene. Vitamin A is a critical fat-soluble vitamin that is important for normal vision, bone growth, reproduction, cell division and cell differentiation. A three-ounce serving of grass-fed beef supplies 10 percent of the recommended dietary allowance of beta-carotene for women, compared to 5 percent from conventional beef. 

The amount of natural vitamin E found in beef raised on a conventional diet is 3.7 micrograms per gram of meat. The amount of vitamin E per gram in beef raised on the grass-based diet is 9.3 micrograms, a nearly threefold improvement. A 3.5-ounce serving of grass-fed beef would yield 930 micrograms of vitamin E, about 7 percent of the daily dietary requirement.

Vitamin E is a fat-soluble vitamin with powerful antioxidant activity. Antioxidants protect cells against the effects of free radicals, which are potentially damaging byproducts of the body's metabolism that may contribute to chronic health problems such as cancer and cardiovascular disease.

Cattle's diet also significantly alters the fatty acid composition of their meat. Cattle fed primarily grass have 60 percent more omega-3 fatty acids and a more favorable omega-6 to omega-3 ratio. Omega-3 fatty acids reduce inflammation and help prevent heart disease and arthritis. Omega-6 promotes inflammation, blood clotting and tumor growth. Because the two substances work together to promote good health, it is important to maintain a proper balance of omega-3 and omega-6 fatty acids. The essential fatty acids are also highly concentrated in the brain and appear to be particularly important for cognitive and behavioral function.

Raising cattle on grass boosts the beef's level of a conjugated linoleic acid (CLA), a lesser-known but important group of polyunsaturated fatty acids found in beef, lamb and dairy products. Over the past two decades, numerous health benefits have been attributed to CLA in animals, including a reduction in cancer, heart disease, onset of diabetes and accumulation of body fat. To achieve these benefits, the average person should consume about 5 grams of CLA per day. A 3.5-ounce serving of grass-fed beef provides 1.23 grams of CLA, 25 percent of the daily requirement. The same amount of conventional beef provides less than 10 percent of the daily requirement.

Details about the health benefits of grass-fed beef, citations for all the research used in this study, and additional resources for consumers, grass-fed beef producers and ranchers considering raising grass-fed beef are on the Web site, www.csuchico.edu/agr/grassfedbeef/ . The site includes recipes, product labeling information, a cost study and producer contacts