Merck plans to conduct the biggest ever test of its
kind in an effort to reintroduce the weight-adding drug into the
United States and Canada after suspending sales last August. A test
herd of this size is currently worth up to $500 million.
Feedlot owners, however, are reluctant to participate in the study
until they get a guarantee that slaughterhouses will be willing to
buy the Zilmax-fed animals.
Snags with the study, whose size was confirmed to Reuters by Merck,
have not been previously reported.
"I'd be happy to sign up, just as soon as Merck tells me who is
going to pay me after they're done," said a feedlot owner in Texas.
"It's been a horrible time, with the drought. I can't afford to give
away a steer, let alone hundreds."
Cargill Inc and Tyson Foods Inc, two of the world's largest beef
processors, told Reuters their stance on Zilmax had not changed
since last autumn, when they stopped accepting cattle fed the drug
following reports it may cause lameness. Together the two companies
control 37 percent of the daily U.S. beef processing capacity.
Reuters reported in December that Tyson stopped taking Zilmax-fed
livestock after more than two dozen animals that had been fed the
drug arrived at one of its slaughterhouses with missing hooves.
The beef processors said their ban would remain until Merck had
scientifically proven that Zilmax was safe for animals. They also
want certainty that key export markets in Asia and elsewhere will
accept such beef products.
Merck has said it is confident in the "safety and performance" of
Zilmax. The U.S. Food and Drug Administration has deemed the drug
safe for both animals and humans.
A source with National Beef Packing Company said the company was not
accepting Zilmax-fed cattle. JBS USA Holdings Inc, another major
beef processor, did not return calls and emails for comment.
Merck in December said the evaluations would start in the first
quarter. But company spokeswoman Pamela Eisele declined to say this
week where the 240,000 cattle would come from in the United States,
whether the tests had started, or whether Merck had signed up any
packing plants, ranchers or feedlots — which house and fatten up the
cattle before they are slaughtered.
Eisele said the company's current plan was to sign up at least 50
U.S. feedlots, out of more than 73,000 nationwide, to participate in
field tests over several months. Merck hopes to enroll five to 15
feedlots for each slaughterhouse that agrees to process the cattle,
Anne Burkholder, who runs a 3,000-head feed yard in Cozad, Nebraska,
is eager to hear results.
"We need to have a large study, where we can really look at mobility
and well-being issues we're seeing in the present," said Burkholder,
who switched to another feed additive after Merck suspended Zilmax
She said she never had any problems with Zilmax.
[to top of second column]
QUESTIONS ABOUT STUDY
The attempt to launch a large-scale study underscores Merck's
determination to put zilpaterol-based Zilmax, once the
largest-selling growth drug for cattle, back on the lucrative
agriculture drug market.
The scale is unprecedented for a randomized, controlled study of
cattle, and the logistics involved with tracking so many cattle
"boggle the mind," said Morgan Scott, an epidemiology professor at
Kansas State University.
Merck said it believed the field evaluations will "support the
results of previous studies and the safety of the product."
A principal investigator hired by Merck, who is an epidemiologist
and veterinarian, will oversee the study and analyze data, Eisele
Merck has declined to name the investigator, or any of the
scientists or other academic experts involved in the study, but said
it would release the results once the study was completed.
Some livestock researchers have questioned why Merck has declined to
say who is leading the research effort. Others have criticized the
company for promoting the study's outcome before data are collected
"It would suggest that they've already decided the results," Scott
Christopher Reinhardt, a feedlot extension specialist at Kansas
State University, said meat packers and feedlots will make certain
results are objectively reported. Merck has "a vested interest in
the outcome but their partners don't, so there is sort of a check
and balance in place," he said.
Animal science experts said large-scale field studies — if done well — can offer valuable insight into drug interactions and impacts in
the real world after the initial laboratory vetting required for
federal regulatory approval.
With Zilmax off the market since last August, rival pharmaceutical
firms have grabbed market share. Many U.S. feedlots have switched to
ractopamine-based Optaflexx, made by Merck rival Eli Lily & Co.'s
Elanco Animal Health unit.
(Reporting by P.J. Huffstutter and Tom Polansek.
editing by David Greising and Ross Colvin)
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