Understanding how animals produce CLA and how that influences other important processes is key to harvesting benefits, says Dr. Erasmus Okine.
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Dr. Erasmus Okine
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Much of the key to capturing the potential of CLA lies in understanding how beef and dairy cattle produce this unique fatty acid and how that influences other important processes that impact both production and product quality, says Dr. Erasmus Okine of the University of Alberta. This is the focus of the CLA Network's animal mechanisms module, which in particular has examined animal mechanisms related to CLA isomers CLA 9,11 and CLA 10, 12.
"Our approach has been to better understand the processes within the animal that produce CLA and have related implications for the production and composition of dairy and beef products," says Okine, leader of the CLA Network's animal mechanisms module. "The knowledge we gain from this effort provides us with new opportunities to improve these products, not only in terms of CLA but also in the context of broader related benefits."
Studies by researchers participating in the CLA Network have confirmed that beef and dairy products already contain natural CLA and these natural levels may be increased substantially through simple livestock production approaches, says Okine, who presented an overview of animal mechanisms module progress at the CLA Summit 2007 conference.
Through a combination of several animal mechanism studies, researchers have come a long way in identifying the process by which these microbes take linoleic acid and move it into the two forms of CLA currently of greatest interest – CLA 9,11 and CLA 10,12. Among the key findings, this research has shown that simple dietary manipulation can consistently produce CLA increases of five times or more in milk fat or two-to-three times in beef.
"A major focus for us has been to examine the processes that underlie these increases, as well as to examine the effects of increased CLA on other animal mechanisms that have important implications for production and product quality," says Okine.
Among recent research, this has included a series of studies to investigate the effects of CLA 9,11 and CLA 10,12 on fat formation and deposition in beef cattle. These studies found that feeding modified diets to increase CLA in beef cattle also resulted in carcasses with higher levels of desirable marbling fat and lower levels of undesirable backfat.
"This is a very important finding," says Okine. "With CLA, it appears we have found a simple, cost effective means to reduce backfat and to generate greater volumes of high quality beef with CLA health attributes that will meet premium market demand."
Waste fat has been estimated to cost the North American beef industry approximately $4.4 billion per year – $2 billion to produce and $2.4 billion to remove and ship, notes Okine. In addition, degree of marbling is one of the most important factors influencing the consumer eating experience.
"Our studies have shown an opportunity for using CLA to dramatically reduce a major industry cost and improve the consumer eating experience," says Okine. "Because these benefits are achieved by increasing natural CLA, this further enhances the product health value."
In a study with dairy animals, researchers identified an enzyme in the mammary gland that takes vaccenic acid – a CLA precursor – and transforms it into CLA.
"Learning more about this mechanism will support the development of strategies to optimize CLA levels in dairy products and to target related market opportunities," says Okine.
In the course of this research, Okine and colleagues made several other findings that will assist in understanding the best CLA strategies.
Among these findings, the researchers found that, during the growth phase, CLA 9,11 was shown to have profound effects types of fat cells known as 3+3-L1 fat cells as well as fat cells located outside the muscle. However, this CLA type didn't seem to affect marbling fat cells during the same phase. An additional finding showed that CLA 10,12 tends to decrease lipid formation in all fat cells.
At this stage, these findings are of most interest to researchers. They provide knowledge that will aid the development of CLA strategies to reduce backfat and increase marbling.
Reprintable with credit. Individual articles in the Report on CLA Summit 2007 are available for reprint, with acknowledgement of the source: The CLA Network. For broader reprint requests or reprint assistance contact the CLA Network at CLAnetwork@gov.ab.ca.
