Building Better Beef
January 24, 2011
Grazing cattle can be fed a fish oil-based feed additive to increase the Omega 3 oils in their meat, according to a University of Wyoming study released during the Sustainable Agriculture Research and Extension Center (SAREC) Livestock Field Day in Lingle, Wyo.
Dr. Dan Rule, professor of ruminant nutrition at the University of Wyoming, started the study in 2008 to see whether a fish oil-based supplement could be added to the diet of grass-fed beef to increase the level of Omega 3 oils in their meat.
Omega 3 is an important component in human nutrition, particularly for the health of the heart and brain. However, the human body can’t make the vital fats on its own, so humans have to eat foods high in Omega 3s to meet their nutritional requirements.
“Grass-fed beef is a niche market,” he said. “I wanted to see if the claim that these cattle are rich in Omega 3 fatty acids was valid. I also wanted to see if grass-fed beef could potentially become a source for Omega 3 oils,” he said.
“Grass-fed beef is typically lean, so the concentration of fatty acids is low, but of the fat, the proportion as Omega 3 is typically greater than feedlot-finished beef,” Rule said. “Omega 3 supplementation could increase the Omega 3 concentration of grass-fed beef.”
For the study, 40 Lowline steers were used because of their small frame size, and the limited time of a typical grazing season. The steers were maintained on an irrigated pasture, and supplemented with either a fish oil-based product, a saturated fat product, or a non-fat control supplement.
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“The challenge was how to get them in to feed them the supplement,” Rule said. “There were several problems with this research project from a practicality standpoint. It was hard to get the cattle to come off lush grass to eat a fish sandwich.”
Finally, stanchions were built for the cattle, and the supplement was mixed with molasses and beet pulp. The supplement was measured out into a tub and weighed. The cattle would stick their head in the stanchion, where they would be restrained for a few hours to give them the opportunity to eat the supplement.
The supplement was fed every other day. Once the cattle were finished eating it, the pan was removed and weighed to determine how much they consumed. The control group was fed 1.5 pounds or less per day, and during the course of the study, 26 pounds of fish oil supplement was fed.
“Palatability was a real issue. The intake was all over the board,” Rule said. “Some cattle would eat very little, and some ate it all,” he said. “I question how much you can feed, because at some point you could feed too much, and the beef will taste like fish,” he said.
Some of the assistants who helped with the study, said some of the meat had a distinct “fishy” smell, but there was never a consensus of whether they could taste it in the meat.
During the evaluation, biopsies of fat and muscle were taken after 40 and 100 days on the supplement. The carcass was sampled after slaughter at 180 days. Data was collected on the total Omega 3 fatty acids including alpha-linolenic acid, EPA, and DHA, as well as CLA in the longissimus muscle (LD), subcutaneous fat, and the liver. “The CLA is an important fatty acid to ruminant animals,” Rule said.
Rule was surprised at the results. “Apparently, Omega 3 supplementation is a feasible alternative, but I don’t know how economical it is,” he said. “In LD, changes in fatty acids reflected the supplement intake changes over time.”
Rule explained at slaughter, the total Omega 3 concentration in LD was 24 percent greater in the cattle fed the fish oil supplement than the control group of cattle. When the livers of these cattle were evaluated, the total Omega 3 proportions were 75 percent greater in the group feed the fish oil supplement than the control group, and the fat tissue Omega 3 proportion was 6.7 percent greater.
Rule said fish oil supplements are readily available. However, they have to be ordered through a company – it is not something handled at the local feed store. “They use it in dairy cattle,” Rule said. “But, mostly it is pure fat. One of the more common sources of Omega 3 fat is a calcium salt fish oil that is fed to the animal to allow it to consume fat. However, if too much Omega 3 fat is fed to an animal, it will not deposit into the tissue like it should.”