By P.J. Huffstutter
CHICAGO (Reuters) - Cargill Inc, one of the world's largest beef processors, threw a wrench into Merck & Co.'s plans to reintroduce its feed additive Zilmax, stating it will not accept Zilmax-fed beef into the Cargill supply chain "until we are 100 percent confident the animal welfare issues are resolved."
Cargill told Reuters Wednesday its ban on Zilmax applies both to beef it processes, as well as to cattle in its own feed lots. In addition, Cargill said it will not use Zilmax-fed beef "until Asia and other trading partners accept it in their markets."
Pharmaceutical giant Merck on Tuesday told Reuters that it is seeking to reintroduce Zilmax, the controversial feed additive temporarily pulled from the market in August after reports that it caused lameness in cattle.
A spokeswoman for Merck's Animal Health unit said that while "it is too early to speculate on when we will resume sales for Zilmax in the U.S. and Canada," Merck was pushing forward with its quality control program to ensure the drug was being properly used.
Merck did not immediately respond to request for comment on Cargill's action.
Merck's August decision came after Tyson Foods Inc. <TSN.N> said it would stop accepting Zilmax-fed beef after cattle were observed arriving for slaughter with signs they were having difficulty walking or moving. Reuters had reported in August that, at a major cattle industry conference, an animal-health expert from JBS USA <JBS.UL> had shown a video of lame cattle arriving at its slaughterhouses.
Merck's audit over how its product has been used in the field is ongoing, according to the company. Merck was "committed to completing this as quickly as possible, while also ensuring it is conducted appropriately and with rigorous scientific measures," company spokeswoman Pamela Eisele said in an email Tuesday.
Among other steps, Merck has formed an advisory board that includes representatives from meat processors, cattle feeder operations, producers, veterinarians, academics and industry consultants to review animal safety research data on Zilmax. The company declined to say who had been appointed to the board, which convened for the first time in October.
(Reporting By P.J. Huffstutter; Editing by Tim Dobbyn and Andrew Hay)