by Alan Newport and Andy Vance
On Thursday the country's second-largest beef processor announced it would suspend purchase of cattle fed zilpaterol hydrochloride because of animal welfare concerns.
Tyson Fresh Meats, in a letter to cattle feeders, said its action would be effective Sept. 6, 2013.
Tyson said it would suspend purchases of cattle fed the supplement as an interim measure while the company assesses animal welfare concerns related to the additive. Tyson Fresh Meats has 17 production sites throughout North America and employs nearly 41,000 workers.
By afternoon the manufacturer of zilpaterol, known commercially as Zilmax, fired off a response. Merck Animal Health said the benefits and safety of Zilmax are well documented. The company noted that its product has a 30-year history of research and development and rigorous testing, and that regulatory agencies around the globe have reviewed extensive data and concluded that use of Zilmax according to the label is safe in cattle.
Beta-agonists are feed additives which cause cattle to put on more muscle and less fat late in the feeding period when animals' tendency is the opposite. Many cattle feeders consider beta-agonists to provide a high return on investment.
Tyson's letter laid out this line of reasoning: "There have been recent instances of cattle delivered for processing that have difficulty walking or are unable to move. 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 is one possible cause."
Tyson added, "This is not a food safety issue. It is about animal well-being and ensuring the proper treatment of the livestock we depend on to operate."
These animal welfare issues were a hot topic among panelists Wednesday at a symposium on the use of beta-agonists in Denver, Colorado. The symposium was hosted by the Cattlemen's Beef Board and National Cattlemen's Beef Association during the Cattle Industry Summer Conference.