Research on adding fish oil supplements in grass-fed cattle continues

Lingle – Grass-fed cattle represent a small portion of the beef market, but are becoming more popular with health-conscientious consumers who are looking for a healthier red meat. Dan Rule, professor of ruminant nutrition at the University of Wyoming, started a study in 2008 to see if 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 oils are 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.
    Rule explained his work during the Aug. 23 field day at the James C. Hageman Sustainable Agriculture Research and Extension Center (SAREC).
    A Question of
Omega-3s
    “Grass-fed beef is a niche market,” Rule explained of his study. “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.”
    “My thoughts were that if beef could contain more Omega-3 fatty acids, how would you do that? The Omega-3s needs to be in the muscle, but first you have to get it through the stomach and GI system. How to get it there was a challenge,” he explained.
    Unsaturated fatty acids break down pretty readily in rumen.
    During the study, Rule worked with Virtus Nutrition to use a calcium salt that modifies fat so a good share of those acids passed through the rumen to be absorbed in the intestine and made it into the meat.
    “The initial study looked at the feasibility of this to see if it would work,” Rule explained. “We started with a calcium sulfate fish oil ration mixed with ground up beet pulp pellets and a mineral balance. We fed that to cattle and collected individual intake data. When the cattle were slaughtered, we measured the Omega-3s in the muscle, liver and fat tissue.”
    “We looked at how much Omega-3 got into muscle and liver. The result was intake-related, but we had a very good response,” he said. “The problem was, intake variability was pretty high.”
    Even with the calcium salt added in, the fish oil supplement smelled rank after a period of time. Some cattle like seafood and others don’t, which caused the intake to vary.
Successful feeding
systems
    Two years later, Rule said they have developed a system that could possibility be used by ranchers, if they want to increase the Omega-3s in the meat of their grass-fed beef.
    “The problem is to put this together so it is not labor intensive and is actually doable,” he said.
    To increase the palatability of the fish oil, Rule worked with Hubbard Feeds and Virtus Nutrition to mix calcium salt with fish oil in lick tubs.
    Rule said the cattle like the lick tubs, and are consuming about one half pound a day out of these tubs, which is what he expected.  
    Now Rule is studying the best way to feed the lick tubs to the cattle. He has experimented with supplementing it with both high and low quality pasture and has evaluated the results by looking at serum samples to see how the Omega levels fluctuate.
    In a pilot study, Rule said cattle grazing really poor quality pasture would consume more from the tubs, especially if molasses was added. In evaluating the serum, he found the cattle had three times the amount of Omega-3 compared to other tests.
Evaluating muscle
    Soon, Rule said the cattle will be slaughtered, and they will evaluate the meat for the presence of Omega-3s. The meat is evaluated by taking a sample of the muscle after the animal is slaughtered. The fat is then extracted and analyzed for the type of fatty acids in beef. The fatty acids levels can vary from zero to six, but Rule is primarily interested in the higher levels, which indicate a higher presence of Omega-3s.
    This far into the study, Rule said the problem with the barrels is not being able to control how much each animal consumes.
    If the mixture could be fed with a feed truck, producers could more closely control costs and the diet. Rule said the current mixture in the lick tubs can cost $1,000 a ton for the fish oil and barrel set up.
    “There will be a range in what each animal has for Omega-3 levels because one animal will consume more than another,” he explained.
    Currently, producers would have to provide a range of Omega-3s their beef contains, but technology could be made available in the future that may pinpoint how much Omega-3 each animal has.
    “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 greatly increase the Omega-3 concentration of grass-fed beef.”
    For more information on this or other studies at SAREC, call 307-837-2000 or email sarec@uwyo.edu. Gayle Smith is a correspondent for the Wyoming Livestock Roundup. Send comments on this article to roundup@wylr.net.