Zilmax boosts weight quickly

But meat treated with growth-accelerating drug has been banned in Europe.

In their quest to grow cattle quicker, heavier and cheaper, some beef producers rely on what are called “growth promoters.”

Animal pharmaceutical firms are marketing two such drugs for cattle, including Zilmax. It’s a “beta agonist,” which means it works at the cellular level to transfer more energy cattle get from feed into muscle instead of fat.

Zilmax, the more potent of the two, is made by Merck Animal Health, which boasts the drug can add 24 to 33 pounds to an animal during its last 20 days in the feedlot. Merck said Zilmax “enables an animal’s natural metabolism to more efficiently convert feed energy to lean, healthy, delicious beef.”

But meat from cattle treated with zilpaterol, used in Zilmax, has been banned from the European Union since 1996 because of human health concerns, said Frank Swartenbroux, an administrator with the European Union in Brussels.

“Like ractopamine, zilpaterol is a beta-agonist, and all beta-agonists, even the more recent ones, are considered a risk to public health,” Swartenbroux said.

He added that the European Union has “a longstanding policy of not allowing the administration of veterinary drugs to healthy animals in the absence of a therapeutic purpose.” Studies there show the drugs can induce high heart rates in humans.

Some within the U.S. beef industry also have spoken out against the drug’s use in cattle, arguing that Zilmax can result in tougher meat.

A report last year from the University of Wisconsin extension service noted that, although studies on Zilmax vary, some have reported “slight reductions in marbling,” resulting in “an increase in toughness.”

Cargill is the only one of the big four packers to say publicly they aren’t satisfied with the quality of meat treated with such drugs.

“Cargill has not completely embraced the use of growth promotants due to the potential resulting lower quality of meat,” according to a statement from the company.

However the statement said Cargill has little control over whether such drugs are used by the ranchers they buy from, adding “to keep our plants running and meet customer demand, we find ourselves in a position where we must harvest cattle that have been fed growth promotants...”

David Yates, a technical services manager for Merck, declined to discuss the Cargill comments, but insisted Zilmax is safe and effective, and said he puts meat treated with Zilmax on his family’s dinner table.

“It’s been researched for 30 years now and has been in use for 17 years globally,” Yates pointed out.

He said it also is approved for use in Canada and Mexico and was commercialized for U.S. cattle in 2007.

Not only that, Yates said, but drugs such as Zilmax — along with good genetics — have meant that the beef industry is getting twice as much meat today as it did in 1958 from roughly the same number of cattle.

And that means using fewer environmental resources.

The drugs also have their defenders in the beef industry, including Tim Klein, CEO of Kansas City-based National Beef.

Klein said the drugs allow cattlemen to use less water and less corn, which in turn allows them to fatten cattle to 1,300 pounds 10 days sooner.

However, Klein — whose company is partly owned by a network of feedlots — conceded that if growth promoters are fed to certain cattle, the result can be tougher meat.

Nonetheless, the drugs are in widespread use across America.

“Ninety some percent of cattle on feed are using one of the two beta agonists,” said Steve Kay, a longtime cattle industry observer and publisher of Cattle Buyers Weekly.