Tyson sent a letter to cattle-feeding operations last week, stating it would stop accepting cattle fed on beta-agonist Zilmax as of 6 September. The processor said it was concerned that the drug was one “possible cause” of lameness in cattle entering its processing plants.
Merck Animal Health, which produces the drug, said it was confident in the safety of its product, but had a policy to “vigorously” pursue all reported adverse events, whether or not they were deemed related to the product. “It is a responsibility we take very seriously.”
The company said it would immediately begin a process of re-training and re-certifying farmers and veterinarians feeding Zilmax to cattle, and would conduct a scientific audit, tracing cattle fed on Zilmax from the feedyard to the packaging plant to establish the possible causes of lameness.
“Merck Animal Health will do a thorough review of potential compounding factors – such as nutrition, transportation, receiving facilities, etc. We will perform this audit in conjunction with third-party experts,” said the statement.
It added that it would call a meeting of the Merck Animal Advisory Board – made up of representatives from the cattle feeding and packaging industries, as well as animal health experts – within the next 30 days to review available data and identify any additional management practices needed to guarantee the safety of the drug.
The company stressed that Zilmax was not suitable for animals intended for breeding, or for use in veal calves.
No scientific basis
The National Cattlemen’s Beef Association (NCBA), which represents US cattle farmers, commended Merck for “taking meaningful action to address questions about the impact of Zilmax on animal welfare” and said the company was going “above and beyond” what was required by committing to retrain and recertify every Zilmax user.
The organisation claimed that there was “no scientific basis” that the use of beta-agonists resulted in the animal welfare concerns cited by Tyson, but said it had convened the world’s top animal welfare experts to investigate any possible correlation between the use of beta-agonists and animal welfare issues.
“Our goal is to fully understand how the use of these products impacts animal welfare in real-life conditions. If this process determines the current use of beta-agonists is compromising animal welfare, we will take appropriate action to ensure that every animal raised for food receives the proper care it deserves,” said the NCBA statement.