October 30, 2013
US specialist debunks link between beta agonist and cattle movement
There is no direct link between the use of beta agonist, Zilmax, and its effects on cattle mobility, according to Chris Reinhardt, an extension feedlot specialist for K-State Research and Extension.
In contrary, Reinhardt believes that other factors, including a hot summer weather, may have affect animal movements.
The specialist was discussing the history and future of Zilmax as well as its implications in the cattlefeeding industry during a public webinar held on October 2013.
Zilmax, which serves as a cattle feed supplement approved by the US Food and Drug Administration, has been widely used by USfeedlots for more than five years. "Beta-agonists increase the deposition of lean muscle on the carcass," Reinhardt explains. "They make cattle more efficient at converting grain to muscle. They also help the efficiency of converting an animal carcass into sellable meat."
However, controversy over the beta agonistarises as meat packer, Tyson Foods Inc, announced a suspension of acquiring cattle which are fed with Zilmax. Concerns were raised on whether the product can cause negative effects on ambulatory ability of cattle.
On the international front, South Korea has suspended some US beef imports upon discovery of the cattle feed additive, zilpaterol, in meat products from a JBS USA unit. The action came after Merck & Co, the manufacturer of Zilmax, halted the sales of the beta agonist which is also a zilpaterol-based drug.
Despite the troubling developments, Reinhardt noted that consumer confidence has not suffered a significant impact. "When we compare it to other recent food safety issues, the consumer, either through lack of information or interest, never really became concerned. I was hopeful that it was because they perceived this as a non-event, at least with respect to food safety."
Reinhardt also praised Merck''s decision to withdraw Zilmax from sales. At the same time, he cautioned against oversimplifying the comparison between beta agonists Optaflexx and Zilmax as both are under different sub-classes of compound. Feedlots have turned to Optaflexx, which is manufactured by Elanco and also known as ractopamine, as investigations were being conducted on Zilmax.
The use of feed additives has become a controversial topic in recent times after a video, from an animal health auditor of JBS USA, showed animals with movement difficulties and displaying other signs of distress following the application of a growth drug.
It is also a source of contention among some meat importing countries like China, Russia and South Korea, which have refused to accept products tainted with feed additives.
The turn of events had caused Tyson to suspend the acquisition of Zilmax-fed cattle on September 6, 2013, while Cargill Inc did so on September 30. JBS had stopped the receiving of such animals at a location in Nebraska, US, according to a feed lot owner who delivers cattle to the facility.
Meanwhile, Merck had announced plans to bring Zilmax back for sales in the US and Canada following an audit into the feed additive''s application in the agriculture sector.
"We are pushing forward with a quality control programme to ensure that the drug is being properly used," said a spokeswoman for the company.
However, a date has not been confirmed for the resumption of sales.