The world’s second largest beef processor Tyson Fresh Meats recently announced it would no longer accept cattle fed zilpaterol hydrochloride, a feed additive commonly known as Zilmax, as of Sept. 6. But Iowa cattle specialists say it’s a suspension as of now, and not a complete ban.

"I think it’s important to note that this is just a suspension as of now, that’s at least how it’s written in the Tyson wording," said Lee Schulz, livestock specialist and assistant...