Tyson to stop buying supplement-fed cattle

WICHITA, Kan. – Tyson Foods Inc. told cattle feeders this week it will no longer buy animals fed a supplement that’s designed to bulk them up before slaughter, citing experts who suggest the drug may be causing cattle to become lame.

The decision by the food giant has raised concerns from industry experts that less beef will be available, which would drive up consumer prices. The growth-inducing drugs are approved by the U.S. Food and Drug Administration and help feedyards get roughly 25 more pounds of beef from each carcass. They’ve been increasingly used to offset dwindling cattle herd numbers, especially in the face of last year’s drought.

“There have been recent instances of cattle delivered for processing that have difficulty walking or are unable to move,” Tyson told feeders in a letter Wednesday. “We do not know the specific cause of these problems, but some animal health experts have suggested that the use of the feed supplement Zilmax, also known as zilpaterol, is one possible cause.”

Tyson, one of the nation’s largest beef processors, said the vast majority of the feedback the company has received has been supportive, because it’s being done out of concern for animal welfare, spokesman Gary Mickelson said Friday.

Zilmax manufacturer Merck Animal Health said in an emailed statement Friday that its product is safe for use in cattle. It said studies have found that cattle fed Zilmax have normal behavior and movement.

Merck, based in Summit, N.J., said it will work with Tyson to help identify other causes for the lameness.

Zilmax is mixed in with normal livestock feeds typically 20 days before slaughter. The additives work at a cellular level to more efficiently convert the feed’s nutrients into lean muscle instead of fat.