Zilmax Suspension Will Result in Lighter Cattle

US - The US beef industry has suggested that Merck’s decision to suspend Zilmax could result in an eight pound drop in average fed cattle weights.

22 August 2013

2 minute read

North America

Feeders are expected to switch to a ractopamine based beta-agonist capable of smaller lean weight gains following the cattle mobility and well-being scare to come from Tyson’s processing plants earlier this month.

Early predictions see the swap to Optaflexx leading to an overall drop in beef production for the year, down 0.92 per cent so far in 2013 on 2012 figures.

The two products differ in terms of active drug and the effect of liveweight gain although work similarly, both being beta-agonists.

Zilmax incorporates Zilpaterol and boasts liveweight gains of 19 pounds whereas Optaflexx contains ractopamine and claims to increase steer weight by 15 pounds.

Analysts have noted that the widespread adoption of beta-agonists in early 2012 coincided with cattle weights jumping ‘dramatically’ at the same time. This came some five years after the Food and Drug Administration approved Zilmax for US use in 2007.

Market commentators Steve Meyer and Len Steiner have said that one driver of year-on-year production increase must be beta-agonists.

They added that a year on year increase is evident from February 1 2012 of 19.08 pounds per head, an increase of 2.2 per cent.

While both products lead to superior weight gain in the final feedlot days, greater feed efficiency and lean muscle gain is achieved with Zilmax.

In their daily livestock report, Mr Meyer and Steiner said : “The economic benefit of these products for both feeders and packers is significant and we expect feeders that currently use Zilmax to switch to Optaflexx.

“Therefore, not all of that two per cent production increase will be lost. According to our sources, switching from Zilmax to Optaflexx will probably reduce weights by 6-8 pounds or about one-third of the increase observed in 2012.”

The jury is still out on why sightings of non-ambulatory cattle are being connected with Zilmax although, panels of animal health, nutrition and welfare experts are at work to formulate a concise answer to the Zilmax question.

Merck animal health has remained confident in the safety of the product and has maintained the issue is purely animal well-being and not food safety.

Dr Bradley Johnson, a feedlot and muscle biology expert said that Zilmax is safe as it does not stay in the animals long or accumulate in muscle or fat.