| | Conjugated Linoleic Acid (CLA) has sparked broad interest in recent years for reducing cholesterol and risk of certain cancers. In 2000 a study was conducted at the Lethbridge Research Center, in collaboration with Dr. Randall Weselake at the University of Lethbridge. It was one of the first studies to show that levels of this valuable fatty acid can be dramatically increased in the meat component of ruminants.
The research found that feeding vegetable oil high in linoleic acid, which is converted to CLA in the rumen, boosted CLA levels in the muscle tissue of lambs by more than 200 %. That increase also reduced the percentage of other fatty acids that are considered unhealthy.
Similar results are expected in beef cattle. Our study shows that not only can we significantly increase CLA levels in ruminant meat, but we can do so through simple supplementation of the animal diet. This may lead to practical production strategies for beef cattle which would result in added health benefits for meat consumers. We used safflower oil in our study, which is the vegetable oil with the highest level of linoleic acid. However, sunflower and canola oil, along with some other vegetable oils, have comparably high levels of linoleic acid and could produce similar results.
In a second major finding, we observed one type of CLA molecule reduced backfat and increased lean muscle mass of the lambs. Other studies have shown this effect on hogs and poultry, but to our knowledge, our study is the first to confirm the effects in ruminants. We hope to produce the same results in cattle because excess backfat represents a huge economic loss to the cattle producer.
Ruminant muscle tissue contains a profile of various fatty acids, including CLA. Some are considered undesirable for human health, while others such as CLA are considered beneficial. Since CLA is produced in the rumen through the conversion of linoleic acid we wanted to see if adding linoleic acid to the diet would boost CLA in meat.
In addition to vegetable oil we examined the effects of feeding artificially pre-formed CLA to the lambs. In this study thirteen lambs were examined. Four had diets supplemented with safflower oil and four had diets supplemented with pre- formed CLA. The remaining five received no supplement and were examined in comparison. We found no significant effect on the CLA content in muscle tissue. We believe that the pre- formed CLA was probably metabolized for energy.
The results of a separate study, in early 2000, illustrated the potential benefits of feeding high linoleic acid oil to dairy cattle and goats fed canola oil to produced increased levels of CLA in milk.
Further study is underway with cattle to more thoroughly investigate the benefits of high linoleic acid oil for beef. More advances in CLA research are expected over the next several years as researchers explore production strategies. For more information on advances in CLA research in meat and dairy check the CLA Network Internet website: http://www.clanetwork.com
Original author:
Dr. Zahir Mir
Agriculture and AgriFood Canada,
Research Centre, Lethbridge
Southern Alberta Beef Review - July, 2000 - Volume 2, Issue 3
Updated by Tennis Marx, July 2006 |
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