We already know that 4-in-5 popular restaurant chains have put little to no thought into dealing with the overuse of antibiotics in the farm animals that provide the beef, chicken, and pork for their foods. And though chicken titans like Perdue and Tyson are nudging the poultry industry toward fewer antibiotics, cattle farmers are apparently more reluctant to head the drug-free route because they are making big profits on drugged-up cows.

The Wall Street Journal reports that, with ranchers seeing some of their largest profits ever, they are balking at providing antibiotic-free meat to customers.

Following a drought in 2014 that culled cattle herds to historic low levels, cattle prices have been at all-time highs recently. The price of fresh beef in July was up 11% over the previous year to $6.16/lb.

Grassfed and antibiotic-free beef often sells for a higher price, but some farmers say that making that switch requires additional investment and time. If farmers are already making more now than ever before on cows raised using an abundance of antibiotics, they have little incentive to switch to providing a product that might not be as immediately profitable.

“With a real strong market like that, there’s just no advantage to going to a natural program,” explains one Oregon farmer who has declined to join a local natural beef cooperative.

Antibiotic-free beef only accounts for about 5% of the whole U.S. market, representing around $800 million in sales a year. But the popularity of organic beef has soared by more than 300% since 2011, compared to only about 12% overall growth in the fresh beef business.

And there are more people out there who want to buy the product, at least according to a rep for a natural cattle cooperative — representing 80 ranchers in the Western U.S. — who tells the Journal that “supply is our bigger issue.”

With an apparent shortage of antibiotic-free meat in the U.S. and an industry that is slow to adopt — partly because cows take so much longer to go to market than chickens — some big buyers of the drug-free stuff have had to look across the ocean for beef vendors.

Last year, with beef prices rising and not enough stateside providers to meet its demand, Chipotle — one of only two major restaurant chains to earn an “A” in today’s antibiotics scorecard — had to resort to getting some of its grassfed beef from Australia.

The Journal notes that CKE Restaurants — the parent company of Carl’s Jr. and Hardee’s — also relies on Australian beef for its “All-Natural Burger.”

Antibiotics for farm animals account for around 80% of all antibiotics sold in the U.S. While some of those drugs are used for the genuine treatment of actual diseases, the majority of these antibiotics are provided to the animals — through their feed and water — in doses too low to effectively kill disease-causing bacteria. In fact, this sort of prophylactic, non-therapeutic application of antibiotics is believed to be aiding in the development of bacteria that is resistant to traditional drugs.

A recent investigation by our colleagues at Consumer Reports recently turned up antibiotic-resistant bacteria in 18% of tested ground beef samples. Meanwhile, only about 9% of more sustainably sourced beef contained these nasty pathogens, which turned up a mere 6% of grassfed beef tested for the study.

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