Kay’s Cuts: Zilmax’s cautionary tale

Beef Central, 02/09/2013


A monthly view of the North American beef industry with Steve Kay, publisher of Cattle Buyers Weekly, Petaluma, California.


Neither I nor Beef Central foresaw what would occur within a month of us writing about the use of beta-agonist feed supplements in beef production. But the warning signs about Zilmax were there, especially over cattle well-being and its effect on beef quality.

The Zilmax story in the US is still unfolding. But years from now, it should be taught as a cautionary tale of how not to ignore concerns about a product or a practice. More immediately, the story will force the Australian industry to take an even more cautious, in-depth approach to weighing up Zilmax’s pluses and minuses.

Merck Animal Health, which makes Zilmax, had spent 30 years developing and testing the product. So it felt confident about every aspect of Zilmax. But this wasn’t enough for cattle well-being issues to emerge. These caused Tyson Foods, the US’s largest processor of grain-fed cattle, to make its announcement last month that it would no longer buy cattle fed Zilmax after September 6.

Other packers initially said their buying practices would not change. But Merck’s subsequent decision to pull Zilmax off the market while it conducts an extensive audit gave the packers cover to say they are also stopping buying Zilmax-fed cattle. JBS USA will do so from September 23 and Cargill from the end of the month.

August’s events were startling, but showed how many in the industry turned a blind eye to two key concerns about Zilmax. That’s because Merck had touted Zilmax as a new technology to help cattle feeders make more money and the industry to produce more beef per animal.

Both arguments seemed attractive. The product came on the market as cattle feeders faced US $8 per bushel corn prices and as industry leaders were starting to develop strategies to improve the industry’s sustainability.

Zilmax’s benefits were and are well-known. It can add 24 to 33 pounds (11-15kg) of live weight to fed steers and heifers in their last 20 days of time on feed. It is said to add 1.4pc in a carcase’s dressing percentage. It is said to double the percentage of carcases that grade USDA Yield Grade 1 and halve the percentage of Yield Grade 4s and 5s.

So it produces leaner beef from grain-fed cattle.

There were concerns however about its effect on tenderness. Certified Angus Beef (CAB), the US industry’s most successful branded beef program, expressed such concerns in October 2010, citing feedback from some of its restaurant customers. But Merck reiterated the results of its tenderness tests on Zilmax-produced beef, saying Zilmax had no impact on tenderness.

Cargill also expressed concerns over tenderness after conducting thousands of tests.

Concerns also arose about Zilmax’s impact on cattle well-being.

World-renowned animal handling specialist Dr Temple Grandin raised eyebrows when she stated such concerns. But she saw well-being issues from the start. In the September 2013 issue of Meat&Poultry magazine, Grandin wrote: “When beta-agonists first came on the market, I observed some strange new problems in fed cattle when they arrived at the packing plant. Brahman crosses, Holsteins and many other types of cattle had occasional lots where on hot summer days, cattle arrived that were stiff and sore-footed. A few animals went down and had severe heat stress symptoms. Many people said my reports were just anecdotal.”

Despite these concerns, most cattle feeding operations began to use Zilmax. Packers were more reluctant to accept Zilmax-fed cattle but all were by spring last year. These uptakes meant that in 2012, an estimated 70pc of all the cattle on feed in the US were being fed either Zilmax or Optaflexx, another beta-agonist. Some estimates are that their use by July this year was split 50/50. Merck says that its Zilmax sales in the US and Canada in 2012 totalled US $159 million.

Perhaps because of this widespread use, concerns persisted about how Americans might perceive Zilmax’s use. While beta-agonists are deemed safe for animals and humans, some in the industry feared the social media might start blogging about “cattle on steroids” or spread some other distorted story about their use.

Some industry leaders deemed Zilmax’s use a “ticking time bomb”. Tyson helped defuse that bomb with its decision, based on the very issues that Grandin had observed years earlier.

How long Merck’s suspension of Zilmax sales will last is anyone’s guess. For now, North American cattle feeders will move to using more Optaflexx and feed cattle to heavier weights as corn prices decline.

Whether Zilmax is used again might depend on several factors, including: whether Merck eventually deems it safe at lower usage levels; whether the beef industry feels it can achieve carcase productivity gains without its use; and whether the social media takes up the Zilmax story or not.

The most critical factor however might be the industry’s attitude to beef quality. Apart from tenderness issues, Zilmax produces larger cuts that are more difficult to merchandise in grocery stores and restaurants.

The industry needs to keep improving beef’s overall quality if it wants Americans to keep paying more for it. Zilmax might not fit in that future.


Read Beef Central's July articles on moves to register Zilmax for use in Australian beef production:


Your email address will not be published. Required fields are marked *

Your comment will not appear until it has been moderated.
Contributions that contravene our Comments Policy will not be published.


Get Beef Central's news headlines emailed to you -