Zilmax Feed Additive Sales Halted Amid Cattle Problems

Following recent concerns about the effects of Zilmax feed additive on cattle, Merck has halted sales of the product pending further investigation.

In a statement issued Frida, Merck & Co. announced that sales of the widely popular animal feed additive Zilmax will be suspended.

The decision comes after an earlier statement on August 8, where the drug maker announced that it will launch an internal study into the risk of cattle problems from Zilmax, after reports surfaced that suggested the additive may cause lameness in some animals.

Zilmax is a popular beta-agonist, a class of drugs used to add weight to cattle, pigs and turkey before slaughter. It is given to the animal for only 20 days, but Merck reports the product increases carcass weight by 24 to 33 pounds, while improving tenderness and flavor in the beef.

Tyson Foods, the nation’s largest meat processor, recently announced that it will no longer accept beef from cattle treated with Zilmax. The decision came after cattle that had been given Zilmax were observed having difficulty walking and moving. The company says the final decision was based on animal welfare; however many industry experts point to Zilmax as the cause.

Amid the cattle problems, Zilmax sales will temporarily be halted in the United States and Canada, offering Merck time to conduct the study of the beef additive. Merck plans to establish study protocols, identify feeders and packers to participate in the study which will be overseen from the “feed yard to the packing plant.” The company also said it plans to create a third party team to validate the results of the study.

The company continues to maintain that Zilmax is safe, citing 30 studies since 2007 which validate it’s safety. The FDA will work with Merck along with the U.S. Department of Agriculture to help determine the safety of the product.

Livestock analysts were surprised by Merck’s decision, considering that the company’s earlier announcement about the intention to further study the product did not include a plan to stop sales. Merck’s decision may have come as a result of the slew of recent bad press concerning Zilmax and it’s side effects on animals.

Following Tyson’s announcement, JBS USA, a large U.S. Cattle processor, released a video of cattle exhibiting the same signs of lameness that Tyson reported. The video shows cattle having difficulty walking after being fed beta-agonist additives.

Analysts say the Zilmax cutback could result in a reduced supply of beef starting in the fall; however beef producers and livestock analysts say they do not expect significant changes. They anticipate companies currently using Zilmax will switch to Optaflexx. Optaflexx is a less potent beta-agonist sold by Eli Lilly and Co’s Elanco animal health unit. It is less effective at adding weight to animals than Zilmax.

Cargill, the third largest meat producer and major rival to Tyson Foods, said they will continue to buy cattle fed Optaflexx, calling Merck’s decision to halt Zilmax sales “prudent.”

Analysts predict the halt of Zilmax sales could result in a one percent drop in the production of beef in the U.S. Sales of Zilmax reached nearly $160 million last year alone.