Why Cattle Are Bigger & Bulkier: Drugs

Beef cattle have gotten bigger and bigger due to drugs including Zilmax, which is made by Intervet, a subsidiary of Merck. The average steer sent to a packing plant now weighs 1,300 pounds; in 1975, their average weight was 1,000 pounds. As an April 15th article in the Chronicle of Higher Education reports, a number of animal scientists at public universities help, and are paid by, pharmaceutical companies to advise and persuade farmers and ranches to use Zilmax, antibiotics, hormones and other drugs. The animal scientists and the companies have profited handsomely, even while the effects of these drugs on animals, and on humans, are unknown.

A 2005 survey found that more than two-thirds of animal scientists said they had received money from the industry in the past five years. The money comes not only in the form of research grants that, more and more, pay for “overhead and administrative costs,” but in payments to animal science professors in the form of fees as consultants and speakers.

As the Chronicle of Higher Education notes, while administrators at medical schools around the U.S. have “recently tightened rules to better police their faculty’s ties to pharmaceutical companies,” schools of agriculture have discounted and even rejected criticism about their too-close ties to pharmaceutical companies.

Zilmax could possibly turn the tide. The drug (which Intervet was charging $8,300 per 10-kilogram bag in January) makes cattle so bulked up that the quality of the beef from them has dramatically declined. It is further evidence that animal scientists advocating for the use of such drugs are more in sync with pharmaceutical companies than with farmers, ranchers and their animals:

Meat from the most pharmaceutically enhanced cattle (especially those given Zilmax)can be so tough that some packing plants are refusing to buy cattle fed the drug. Some cattlemen and beef-industry executives have also begun to speak out. They warn that continued use of the drug may make ranchers’ herds difficult to sell, and end up hurting the image of American beef….

Cargill won’t buy cattle that it knows have been fed zilpaterol, he said, using the drug’s generic name. Cargill’s view is that an overly aggressive focus on growth “can have an impact on the consumer attributes of size, quality, and tenderness,” he said. “So we need to find a balance. The message there is that we ask you to be careful.”

Paul Heinrich, an executive of Sysco, the global food distributor, has offered similar criticism about the “Frankenbeef” from cattle on Zilmax; butchers struggle to cut up extra-large carcasses. Ray Bozzacco, meat manager for the Meijer’s supermarket chain in Grand Rapids, Michigan, says simply that “bigger isn’t always better.” In a 2005 beef-industry survey, restauranteurs and food executives complained about “heavy carcasses, inappropriately-sized rib-eyes, and tough steaks that lacked the marbled fat that gives them flavor.”

Few academics offer such warnings, notes the Chronicle of Higher Education. Indeed, Ty E. Lawrence, an associate professor of animal science at West Texas A&M University, and Bradley J. Johnson, a professor of meat science and muscle biology at Texas Tech University, have both written scientific articles about Zilmax with company employees. A 2010 article in the Journal of Animal Science by Lawrence was a review of previously published research — much of it financed by Intervet — on the drug. Moreover, he was the highest-paid associate professor at his university last year, making $101,000 (as compared to the median salary for associate professors there of $60,000).

The effects of drugs like Zilmax on the cattle, and on human beings who eat beef from animals given it, are yet unknown. The FDA has received at least six reports detailing how one or more cattle died after eating feed mixed with Zilmax, says the Chronicle of Higher Education. Temple Grandin, a professor of animal science at Colorado State University, has reported that “Zilmax and Optaflexx appear to cause cattle to become heat stressed and go lame, especially on hot days,” after observing animals in a slaughterhouse.

If so many animal scientists are in, as it were, the pay of pharmaceutical companies, there need to be far more regulations about such relationships, for the sake of consumers and, certainly, of the animals themselves.

Related Care2 Coverage

Single Mad Cow Disease Case Confirmed in California

Beef’s Dirty Secrets (VIDEO)

Cattlemen Ready To Slug It Out With the EPA


Photo by moheroy


Debbie Tate
Debra Tate3 years ago

The drugs they give to the cattle end up in our digestive system! This is why I have reduced my meat intake to about 1/4th or less of what it used to be. I grew up in a "meat and potatoes" home. Now my home is a veggies home and the only time I know I will be eating meat is at family gatherings over the holidays. It keeps the peace with my 90 year old mother as she still cooks!

Carrie Anne Brown

thanks for sharing

Diane L.
Diane L.4 years ago

Yeah, I know, Colleen........and the same people who scream about cows being given drugs to muscle up or breed bigger calves (selective breeding) will go out and buy a designer dog because they think it's cute, or they'll breed their own mutt to whatever without a thought to the results. A hairier dog, smaller dog (Chihuahuas), a taller dog, a "longer" dog (with Doxies), a meaner dog, an uglier dog or whatever is in "fad" is all they care about.

ii q.
g d c.4 years ago


Steve R.
Steve R.4 years ago

Got a couple of chicks from my daughter to keep and raise as pets.

Went to the pet shop to buy food for them and was told I should get some Tetracycline to add to their water for a week or two!

Are they kidding me? That's an antibiotic - to give to perfectly healthy chicks????

Drug company corruption - it's everywhere!

Shar F.
Sharon F.4 years ago

That is very nasty to mess around with animal genetics; leave things alone. Please consider going vegetarian in response to all the genetic engineering and drugs fed to animals. Disgusting!

Diane L.
Diane L.4 years ago

Of course growth hormones are a factor, but so is selective breeding and better conditions under which the most "prime" breeding prospects are kept. Humans are bigger than they were centuries ago, or even decades ago. As a long time horse owner, I know that my breed of choice is now much taller than their ancestors were. It's from better feed, less harsh environment and better vet care. The biggest, most "fit" animals are kept for breeding, so it only makes sense that eventually, the offspring of those animals will result in being bigger, themselves.

Brenda Towers
Brenda Towers4 years ago

Happy to be a vegetarian.

Yvette S.
Yvette S.4 years ago

This abusive to animal and human If you get a disease and the only treatment is antibiotics good luck!!!

John S.
Past Member 4 years ago

Thanks for the information.