Merck Animal Health has decided to temporarily suspend sales of the feed additive Zilmax (zilpaterol hydrochloride) in the U.S. and Canada. The company says, "This will allow sufficient time for the establishment of valid study protocols, identification of feeders and packers to participate in the audit, and creation of a third-party team to oversee this process and validate its results."
Earlier this week, Merck announced a five-step plan to conduct a scientific audit that will "monitor the process of feeding of Zilmax, and will follow identified cattle from the feedyard to the packing plant to determine potential causes of lameness and other mobility issues during feeding, transportation, offloading and staging at the processing facility. We also will do a thorough review of potential compounding factors—such as nutrition, transportation and receiving facilities."
The Food and Drug Administration (FDA) says it is working with Merck and USDA (but not in a joint study or scientific investigation) to monitor the situation and gather information as to whether the feed addititive is safe, according to Reuters newswire. FDA reportedly told Reuters it has received "a very small number" of reports of "lameness or lying down" in cattle whose feed contained zilpaterol.
These actions came in response to news earlier this month that Tyson Foods will stop buying cattle that are fed Zilmax as of Sept. 6 due to mobility concerns with the animals. National Beef Packing Co., Cargill and JBS have said they will continue to buy cattle finished with Zilmax and other beta agonists.
"We remain confident in the safety of the product, based on our own extensive research and that of regulators and academic institutions, and are committed to the well-being of the animals that receive it," says KJ Varma, BVSc, Ph.D., Diplomate ACVCP, Senior Vice President Global R&D, Merck Animal Health. "This important step demonstrates our commitment to providing our industry partners with data that will reaffirm confidence in Zilmax. We sincerely regret that this situation creates business challenges for our customers but it is critical to ensure that this process is conducted appropriately and with rigorous scientific measures. After the five-step plan is completed, the results will be shared publicly."
Merck says it is also accelerating the development of its Animal Health Advisory Board, which will bring industry experts, producers and company leadership together for discussions about animal well being.
Zilmax sales in the United States and Canada were $159 million in 2012.
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