A health auditor for the world’s leading producer of beef, JBS, presented a video at a beef industry conference last week in Denver, showing sick cows struggling to walk and displaying signs of distress. The presentation was part of a panel discussion on beta-agonists, a class of drugs fed to cattle in the weeks before slaughter in order to add up to 30 pounds of body weight and to reduce fat.

Dr. Lily Edwards-Callaway, the head of animal welfare at JBS USA told the conference attendees that the cattle in the video had been fed beta-agonists, but did not specify which brand, according to Reuters.

On the same day that the video was shown at the Denver conference, Tyson Foods, Inc., the US’s largest meat producer, announced that it would no longer accept cattle that had been fed the most popular brand of beta-agonist, Zilmax. The drug is manufactured by Merck & Co., a corporation that has shown little concern even for the safety of drugs it manufactures for its human consumers.

Tyson reportedly said their decision was not related to food safety issues, but a concern over the animals’ behavior that experts said could be connected to their consumption of Zilmax. Many in the industry believe that Tyson’s decision was purely a marketing one – that the company hopes to boost sales of their products in other countries where the use of drugs like Zilmax is banned.

Pharmaceutical giant, Merck, told Reuters that Zilmax is not the cause of the distressing animal behavior seen at Tyson facilities, and stated that their drug is safe for animals.

Last year, The Chronicle of Higher Education issued a report about animal scientists in the pockets of pharmaceutical companies like Merck. The report, “As Beef Cattle Become Behemoths, Who Are Animal Scientists Serving?”  highlights the relationship between corporations and scientists, where scientists act as salesmen for the companies’ animal drugs, “Convincing ranchers that [drugs like] Zilmax will transform their cattle into ‘bovine Schwarzeneggers’…”

Animal scientists employed by public universities help pharmaceutical companies “persuade farmers and ranchers to use antibiotics, hormones, and [beta-agonist] drugs like Zilmax to make their cattle grow bigger ever faster,” the report states.

The relationship is profitable for both the pharmaceutical corporations and the professors and universities. Universities increasingly depend on the industry for research grants, and many professors put money into their pockets by acting as consultants and promoters for the companies.

According to The Chronicle, “the close relationship between animal scientists and pharmaceutical companies” ensures that few scientists have been interested in looking at the potential dangers that livestock drugs may cause to the animals and thereby the people consuming the meat. With the introduction of Merck’s drug, Zilmax; however, the line between industry and scientists became even more blurred.

Not surprisingly, there has been concern that academic animal scientists have become so friendly with pharmaceutical corporations that they may be working more in the companies’ interests than in the interest of farmers, ranchers, and consumers.

Growth-promoting drugs for livestock have long been controversial.

Zilmax and other livestock-bulking drugs like ractopamine have been banned by the European Union, China, Taiwan, and over 100 other countries due to concerns about drug residue on human health. Ractopamine, manufactured by Elanco, is a beta-agonist widely used by the US pork, beef, and turkey industries. About 80 percent of the US pig herd is fed the drug every year, the Huffington Post reports.

Ractopamine was approved by the US Food and Drug Administration (FDA) in 1999, based solely on research provided by Elanco. Other countries, who also refuse to import US meat from animals that have been fed the drug, found that Elanco’s data did not support their claims of safety about the drug.

The FDA-approved drug is labeled “Not for use in humans. Individuals with cardiovascular disease should exercise special caution to avoid exposure. Use protective clothing, impervious gloves, protective eye wear, and a NIOSH-approved dust mask,” according to AlterNet.

Like Zilmax, ractopamine is fed to livestock in the weeks or days before slaughter, meaning that the drugs remain in consumer meat.

Alisha is a writer and researcher with Ring of Fire. Follow her on Twitter @childoftheearth.