A public webinar that will take place on October 29th will focus on the history and future of Zilmax, formally known as zilpaterol hydrocholoride, and its implications on the cattle feeding industry.

It will be led by Chris Reinhardt, extension feedlot specialist for K-State Research and Extension.

Zilmax is a beta-agonist, or cattle feed supplement, approved by the US Food and Drug Administration. Feedlots have used it to improve the cattle’s natural ability to convert feed into more lean muscle.

„Beta-agonists increase the deposition of lean muscle on the carcass,” Reinhardt said. „They make cattle more efficient at converting grain to muscle. They also help the efficiency of converting an animal carcass into sellable meat.”

Although the product has been widely used in the US for more than five years and is considered safe from a food safety perspective, major US meat packer Tyson announced it would suspend buying cattle fed Zilmax on Sept. 6, 2013, due to an animal welfare concern. The concern involved questioning if the product affected the ambulatory ability, or movement, of cattle. Merck, the manufacturer of Zilmax, voluntarily suspended sales of the product to collect more data.

Reinhardt said there has been no direct link between the use of Zilmax and cattle mobility, as many things, including hot summer weather, can affect animals’ ability to move. He said pulling the product has simply allowed for more investigation to see if it played a role.

While Zilmax sales have been temporarily suspended for the investigation, Reinhardt said many feedlots have switched to a competing beta-agonist called Optaflexx, or ractopamine, which is manufactured by Elanco. Reinhardt plans to address the complex nature of beta-agonists and also what he sees in the future of cattle feedin