Meristem: Beef Science

A little "rumen magic" could go a long way to boosting the health value of dairy and beef products, says a team of livestock researchers.

Scientists in the CLA Network are taking advantage of the unique ability of the rumen to act as a virtual factory for producing natural conjugated linoleic acid (CLA), a type of beneficial fat that early animal studies have linked to considerable potential for battling chronic disease in humans.

"The more we learn about the ability of the rumen to produce natural CLA, the more good news there is for consumers and for livestock industries," says Dr. Erasmus Okine, a ruminant nutritionist at the University of Alberta. "We know that rumen processes produce CLA that is transferred into dairy and beef products. We also know levels of this natural CLA can be increased substantially in these products through simple changes to common livestock production practices."

Okine, who is also Chair of the Department of Agricultural, Food and Nutritional Science, is one of many leading researchers aiming to identify and take advantage of CLA opportunities, as part of the CLA Network.

Founded in Canada, the CLA Network is a collaborative team from academia, industry and government, including representatives from many areas of expertise such as research, food industry, health and communications. Together, they are working to harvest the expanding health potential of CLA in dairy and beef products.

"A key focus for the CLA Network is investigating the effect of livestock production practices on CLA levels," says Okine. "This is leading toward practical production strategies for increasing CLA content in dairy and beef products."

The unique potential for enhancing natural CLA in these products stems from the power of the rumen - the first compartment of the stomach of a ruminant animal, where food is collected and returned to the mouth as cud for chewing.

Though the rumen structure is relatively basic, it contains billions of bacteria and other microorganisms. These make the rumen the densest microbial community, and the best one at degrading plant fibre, known to exist.

In the case of CLA, the advantages of the rumen come in to play when the animal digests plant material to release linoleic acid - a beneficial fatty acid that facilitates a number of basic biological processes in humans. The microorganism activity in the rumen alters linoleic acid, which results in the creation of CLA as well as CLA precursors.

The CLA that is created by this process has the same health facilitating properties of linoleic acid. However, the new conjugated form has the valuable additional abilities to displace unwanted types of fat and to act as an anti-carcinogen. Early animal studies have shown considerable CLA potential for human health benefits related to cancer, heart disease, obesity, diabetes, kidney disease and bone density.

On the livestock production front, researchers over the past decade have undertaken pioneering studies to examine the role of production practices in influencing CLA levels.

"Currently, it is generally considered reasonable to get about a two- to four-fold increase in CLA in milk fat through relatively simple dietary manipulation," says Dr. David Glimm, a dairy nutrition research associate at the University of Alberta.

Results in beef animals are also encouraging, says Dr. Priya Mir, a ruminant nutritionist and physiologist at Agriculture and Agri-Food Canada in Lethbridge, Alta. "Indications are CLA can consistently be doubled with simple modifications to production practices."

Further information on the effort to increase CLA levels, including further perspective from Okine, Glimm and Mir, is featured in a new article available on the Web, at www.CLAnetwork.com. Background information on the CLA Network and a range of other articles on CLA progress - with new items added regularly - are also available on the site.

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'Rumen magic' to boost dairy and beef health value