by David Bowser

Flaxseed oil in beginning rations appears to benefit the health of cattle on feed and improve the quality grade of their beef. There doesn't appear to be any detrimental impact on the flavor of the beef.

Dr. Jim Drouillard, feedlot nutritionist at Kansas State University, said research done at Kansas State concerning calves brought into feedyards from out of state first caught his interest that led to the flax investigation several years ago.

In a study dealing with enhancing the immune response of cattle and stress reduction, Kansas State was doing research with byproduct feed, onion residue. The residue came from a plant in south central Nebraska that was making onion rings.

Researchers took scraps of onions that didn't make it out whole from the fryer and fed it to cattle.

"We had a phenomenal impact on the health of the animals," Drouillard said. "We really couldn't figure out what that was."

They looked at the onions because onions and similar plants, such as garlic, have been credited with some medicinal benefits.

"We kind of pursued that," he said. "We looked at the produce that was all onion without the fryer waste, without the oils and all that."

That led to an opposite effect.

"We killed more cattle, and we made more of them sick," Drouillard said.

Digging deeper into the problem, they discovered it was the content of a particular fatty acid, linolenic acid, an omega-3 fatty acid in the oil used in the fryer.

"As it turns out," Drouillard said, "it's one of our dietary essential fatty acids."

That led them to look at flaxseed as a potential means of improving the immune response in cattle.

In treatments for bovine respiratory disease, he said, about 55 percent of the cattle with no fat in the diet were treated at least once.

Flaxseed oil basically cut the treatment numbers in half.

Looking at second and third treatments, cattle fed flaxseed oil clearly stood out as not needing as many treatments.

Drouillard warned, however, that there still needs to be more research done in this area.

"You have to have a lot of studies before things really start becoming clear," Drouillard said.

While individual studies have been misleading, he said, the bulk of the studies indicate that the flaxseed oil is responsible for the response they were looking for.

"The next question we asked is whether there is potentially a downside associated with flax," Drouillard said. "The oil that is in flax has a predisposition for oxidation."

Downstream in the production process, potential problems with fed cattle could develop.

"We looked at feeding cattle an additional 180 days after we removed flax from the diet," Drouillard said. "This is where we really got some surprising results, some very unexpected results."

The cattle had different fat sources, including flax, in their diets during the first 35 days. Then they were fed an additional 180 days without the fat sources.

Looking at carcass weight, the control group averaged 663 pounds. The cattle fed tallow averaged 668 pounds. The cattle fed flaxseed averaged 670 pounds. The cattle fed the flaxseed oil averaged 680 pounds.

"We get a bit of an improvement by feeding tallow," Drouillard said. "A little bit more improvement feeding flax, but quite a bit more improvement as the result of feeding the flaxseed oil."

Carcass weights from the cattle fed a ration with linseed meal and tallow dropped off to less than 656 pounds.

Linseed meal is flaxseed with most of the oil squeezed out of it, although Drouillard said that the linseed meal retains some residual fat.

Yield grade on the carcasses didn't change very much, but quality grade was remarkable.

About 69 percent of the control group of cattle graded Choice or Prime. That number dropped to 67.4 percent for the cattle fed tallow the first 35 days in the feedyard, but it rose to almost 83 percent for cattle fed flax. The cattle fed flaxseed oil graded more than 93 percent Choice and Prime. The cattle fed linseed oil and tallow graded 82 percent Choice and Prime.

"In this particular treatment we had 39 Prime carcasses," Drouillard said.

He said there have been a number of studies indicating that a relative short term exposure to flax can result in a large residual effect.

"We really didn't change the yield grade appreciably with our different treatments," Drouillard said, "but we had a huge impact on the percentage of Choice and Prime cattle."

A sensory panel, however, determined that feeding flax is not going to have an impact on the flavor profile of that meat.

"Short term exposure to the flax or flax oil," Drouillard said, "can have a pretty large impact on fat deposition, particularly the fat that is deposited in the marbling."

Exposure to the flax, he said, does not seem to have any negative impact to the beef's flavor. ©