Grass-fed beef may not have as many healthful traits as some perceive, according to results from a recent Texas AgriLife Research study.
Dr. Stephen Smith, an AgriLife Research meat scientist, and a team of researchers have found that contrary to popular perception, ground beef from pasture-fed cattle had no beneficial effects on plasma lipid.
However, high monounsaturated fat ground beef from grain-fed cattle increased HDL cholesterol, increased LDL particle diameters, and decreased insulin, suggesting that ground beef produced by intensive production practices provides "a healthful, high-quality source of protein."
"We wanted to see from this study if product from pasture-fed and corn-fed cattle had different effects on LDL or HDL cholesterol," Smith said. "We looked at the scientific literature and could not find any justifications for the statement that pasture-fed beef is better for you. All we found were rat studies in which they were fed omega-3 fatty acids, so we wanted to know if this applied to beef from grass-fed cattle."
The study, funded by the National Cattlemen's Beef Association, used Angus cattle raised at the McGregor AgriLife Research Center. One group of cattle was fed a pasture diet with supplement hay.
The steers were kept on pasture until 20 months of age. A second group of Angus steers was fed the same way a feedlot operator would and kept on a corn-based diet until 16 months of age, then reaching U.S. Department of Agriculture Choice status.
A third group of Angus steers were fed the corn-based diet the longest, until reaching USDA Prime. The fat in cattle that are high in marbling is low in saturated and trans-fats, and higher in monounsaturated fats.
"There really were no negative effects of feeding ground beef from the pasture-fed cattle," Smith said. "We did see many positive effects in men that consumed ground beef from corn-fed cattle. The ground beef from the USDA Prime cattle increased HDL cholesterol and LDL particle diameter. Both effects are protective against cardiovascular disease.
"The Prime ground beef also decreased insulin, so it may have some protective effect against type II diabetes."
"I know that cattle are adapted to growing on high-roughage, pasture diets, but my focus is the beef product," he said. "A lot of producers are receptive. What I*m trying to show them is that the longer cattle are fed a corn or grain-based diet, the healthier the product will be."
"I realize cost is involved - feeding corn is expensive. But, if you want a healthier product, you need more marbling. Time on feed is a big factor."
The study team included Dr. Rosemary Walzem, AgriLife Research poultry scientist, and Dr. Stephen Crouse, researcher from Texas A&M University*s health and kinesiology department.
Crop tour on Friday
The Annual Nueces County Crop Tour will take place on Friday, with registration at 8:30 a.m. at the Texas AgriLife Research and Extension Center at 10345 State Highway 44, just west of the Corpus Christi International Airport, followed by the tour bus departing promptly at 8:45 a.m.
In addition to touring the traditional cotton and grain sorghum variety tests and a cotton plant population study, the tour will also feature a tour of the new Drought Research Laboratory. Other topics to be addressed during the tour event will include: New Grain Sorghum and Cotton Technology, Weed Herbicide Resistance Management, Sorghum Harvest Aids, Algae Research in Coastal Bend, Boll Weevil Eradication and Pesticide Laws.
Pesticide applicators and Certified Crop Advisors will be able to obtain three continuing education units for participation in this event, which will conclude by 2 p.m. The tour is being sponsored by the Nueces County Extension Crops Committee, Texas AgriLife Extension Service and numerous agribusinesses.
Educational programs of the Texas AgriLife Extension Service are open to all people without regard to race, color, sex, disability, religion, age, or national origin. Individuals with disabilities, who require an auxiliary aid, service or accommodation in order to participate in any of the mentioned activities, are encouraged to contact the County Extension Office eight days before all programs for assistance.
Jeffrey Stapper is the Agricultural and Natural Resources Agent for Nueces County. Readers may contact him at 767-5217.