WICHITA, Kan. – Cargill announced that the company supports Merck Animal Health's decision to pull Zilmax from the market, and that the last of the company's cattle being fed Zilmax will be out of its supply chain by the end of September.

Merck recently announced it was temporarily suspending sales of Zilmax in the United States and Canada to conduct a scientific audit of Zilmax and the process of feeding the beta-agonist to cattle. The company said suspending sales would allow time to establish valid study protocols, identify feeders and packers to participate in the audit, and create a third-party team to oversee the process and validate its results.

"Cargill believes Merck’s decision to suspend sales of Zilmax until additional research can be conducted is prudent," the company said in a statement on its website. "Consequently, Merck has reached out to the industry and one of the steps it is taking involves the creation of an advisory board. Dr. Mike Siemens, Cargill’s head of animal welfare and husbandry, will represent Cargill on that board."

After years of studying the drug, Cargill said the company was the last major beef packer to allow cattle fed Zilmax into its beef supply chain in June 2012, the company said.

"One reason Cargill was initially reluctant to accept cattle fed Zilmax was a series of extensive beef tenderness tests that created concern about potential impact to product quality," the company said. "During the years from 2006 to 2012, best practices were developed by the company’s cattle procurement and Research & Development teams to ensure product quality."

Cargill said the company would suspend purchases of Zilmax-fed cattle in North America, pending research being conducted by Merck Animal Health.

Springdale, Ark.-based Tyson Foods Inc. said the company would no longer purchase cattle that are fed the growth promotant because of concerns about cases of cattle with difficulty walking. Tyson said it would suspend purchases starting Sept. 6.