Merck Animal Health has issued a statement about its Zilmax feed additive, which was pulled from the marketplace several months ago. The drug was pulled after Tyson Foods announced it would no longer use the drug in its production operations, after noticing that some cattle on the drug were experiencing mobility problems.

The company said in a statement:

“During the last 90 days, Merck Animal Health, with the input and oversight of its Advisory Board, has worked to implement its Five-Step Plan to Ensuring Responsible Beef and has made considerable progress. The findings that come as a result of the plan will add to the significant amount of data that already exists for Zilmax (zilpaterol hydrochloride), including numerous animal safety and well-being trials. Zilmax is a feed supplement approved by the FDA and other regulatory authorities. While we have made considerable progress, it is too early to determine when Merck Animal Health will return Zilmax back to the market in the United States and Canada.  

"At Merck Animal Health, we continually evaluate our processes and procedures across the entire company to ensure that we maintain the best science-based practices and procedures for the health and well-being of animals," says KJ Varma, BVSc, Ph.D., Senior Vice President Global R&D, Merck Animal Health. "Our five-step plan is a direct reflection of that commitment to science. It also reflects our commitment to working with our industry partners to maintain the highest standards of care for the health and well-being of cattle. We are pleased to be able to tap into the vast knowledge and expertise of professionals from throughout the industry to help us carry out this significant undertaking."

The implementation of the five-step plan has included the following key components.

Merck Animal Health Advisory Board 
Formed in August, the Merck Animal Health Advisory Board is comprised of representatives from packers, large, medium and small cattle feeder operations, cow-calf producers, veterinarians, academia and industry consultants. In addition to helping the company maintain an open dialogue on animal well-being, beta agonist use and related matters, the objectives of the Board include:

  • Review all available animal safety and well-being research data on Zilmax
  • Review the existing Zilmax Quality Assurance program (ZQA) and make recommendations, as needed
  • Provide input on the certification and scientific audit processes; and
  • Review and provide guidance on best management practices for using Zilmax

The advisory board has provided input on, reviewed and approved all initiatives in support of the plan. 

Certification Process 
To help further ensure safe and effective product use by customers, a formal certification process has been developed. As part of the certification, every feedyard team member, nutritionist and veterinarian who uses Zilmax or provides consultative services on feeding Zilmax to cattle must be trained annually on the proper use of the product.

The training will focus on safety practices, product handling, mixing protocols, cattle management, product inventory, record keeping and clean-out procedures. Every certified operation will also be required to pass an initial homogeneity test to ensure proper mixing practices, as well as four additional feed mix tests throughout the year. Before a feedyard can participate in the Zilmax Field Evaluations, the operation will need to be certified.  

Zilmax Field Evaluations
In addition to implementing the certification process, the company has also worked with its Advisory Board to develop and finalize the protocol for the field evaluations for Zilmax-fed and control cattle (previously noted as "scientific audit"), which are expected to begin in Q1 2014. 

  • Observing cattle throughout the system - before and after receiving Zilmax - at the feedyard and at the packing plant
  • Evaluating the mobility of cattle by trained third-party experts utilizing an established mobility scoring system  
  • Reviewing potential compounding factors, such as nutrition, transportation, receiving facilities, flooring surfaces, and cattle management and handling practices

The field evaluations will take place with the oversight of a well-known independent epidemiologist and veterinarian, who will serve as principal investigator and collect all data, analyze results and publicly communicate findings in support of the company's commitment to transparency and communication. 

"We at Merck Animal Health remain highly confident in the safety of Zilmax, which is supported by the results of more than 30 studies, totaling 65,000 cattle that were conducted by well-respected universities and third-party experts," says Dr. Varma.  "We believe the field evaluations we are conducting as part of the five-step plan will support the results of previous studies and the safety of the product, and we are confident that they will help create a greater understanding of the best management practices that are so vital to helping ensure the well-being of cattle."  

For additional information about the Five-Step Approach to Ensuring Responsible Beef, please visit: http://www.merck-animal-health-usa.com/news/2013-8-13.aspx.

Source: Merck Animal Health