CLA in Angus Beef: What the Research Says

Conjugated linoleic acid, usually shortened to CLA, is a group of fatty acids found naturally in the meat and milk of ruminant animals such as cattle. It shows up often in discussions of grass-fed beef, sometimes with strong health claims attached. This article explains what CLA is, how it gets into beef, what we can say about how finishing diet changes it in Angus and other cattle, and why caution about health claims is justified.

What CLA is and where it comes from

CLA is a family of fatty acids that are variants of linoleic acid, an omega-6 fat. Beef contains several forms, and the most abundant is usually called c9,t11 CLA, also known as rumenic acid. It forms when microbes in a ruminant's stomach partially convert the polyunsaturated fats in feed, a process called biohydrogenation. One related intermediate, trans-vaccenic acid, can also be converted into c9,t11 CLA in the animal's tissues. This is why CLA is found in beef and dairy from ruminants but not in significant amounts in most plant foods or in pork and poultry.

What finishing diet does to CLA

A 2022 review in Frontiers in Sustainable Food Systems reported that grass-fed beef contains about twice as much CLA as conventional beef, and that forage-fed cattle have roughly two to three times higher levels of c9,t11 CLA and trans-vaccenic acid than grain-fed cattle. The review did not give absolute concentrations in the portion we could access, and it did not focus on a single breed. That means the pattern is well described, but you should look at individual studies for the actual amounts in Angus.

The reason forage helps is not that grass contains CLA itself. It is that forage supplies the precursors, and a forage-heavy rumen environment favors production of the intermediates that become CLA. Grain-heavy rations tend to shift rumen conditions in ways that change which intermediates form. That is why finishing diet and the length of time on forage both matter, and why two grass-finished products can differ.

Is it beneficial?

Headlines have linked CLA to a range of potential benefits in laboratory and animal work. Human evidence is thinner and less consistent, and amounts in beef are small compared with the doses used in some supplement studies. We were not able to retrieve a review with a clear human-health conclusion to cite for this article, so we are not going to state one. What we can say is what researchers themselves say about beef composition in general: a 2024 study of Black Angus beef in Scientific Reports found differences in many compounds between pasture and feedlot finishing but cautioned that human trials are required to assess health effects. The same caution applies to CLA. If you have a medical reason to care about specific nutrients, talk to a qualified health professional.

What affects CLA in your cattle

Feed and forage

Fresh, high-quality forage is the main lever. Mature or stored forage generally supplies less of the fatty acid precursors than lush growth does. Farm.fm's page on what Angus beef is gives general background, and the University of Nebraska-Lincoln beef site carries research on finishing and forage-based systems.

Time on feed

Cattle that spend more of their finishing period on forage carry more forage-derived fatty acids. Switching to grain late in finishing moves the profile partway back.

Supplements

Some supplements, including certain oils and byproduct feeds, can change rumen fatty acid pathways. Results vary and you should consult a qualified nutritionist before changing a ration for this purpose.

Animal and fat deposition

Differences in total fat influence concentrations per gram of meat. Reports may express CLA as a percentage of fat or as milligrams per gram of beef, and the two can tell different stories.

Marketing responsibly

If you sell grass-finished beef, it is reasonable to say that forage-finished beef tends to contain more CLA than grain-finished beef, citing published work. It is not reasonable to claim that eating your beef will prevent or treat disease. Regulators scrutinize health claims on food labels, and you should check current rules from the U.S. Food and Drug Administration and USDA's Food Safety and Inspection Service before putting any nutrition claim in print. To reach customers interested in forage-finished beef, the agriculture directory is a helpful place to start.

For shoppers

If you buy beef for its fatty acid profile, keep expectations realistic. The amounts of CLA in a serving of beef are small, and beef is one food among many. Choose beef because you like how it tastes and how it was raised, and treat any nutrition difference as a minor bonus. The American Meat Science Association offers accessible information on meat composition and quality.

Bottom line

CLA is a naturally occurring fat in ruminant beef, and forage finishing is associated with higher levels. The health significance for people remains less certain than marketing suggests. Verify claims against original studies and current regulations, and note that this site is independent and not affiliated with the American Angus Association or Certified Angus Beef.