Ethanol byproducts serve as another source of antibiotics in livestock feed.
A report calls out a dangerous habit used in farming and energy industries.

For the last several decades, doctors have been warning about the dangerous practice of routinely feeding antibiotics to healthy animals. Many farmers do this in an attempt to ward off disease in crowded conditions and to speed growth, but public-health researchers have linked the overuse of antibiotics in farming to the sharp rise in hard-to-kill - and sometimes fatal - superbugs in people.

While the use of antibiotics in readying farm animals for consumption is no secret to most Americans, another source of antibiotics likely is. A new report from the Institute for Agriculture and Trade Policy calls out a surprising way the drugs wind up in the livestock many Americans eat: the process of producing ethanol.

It All Starts With Corn

To create crop-based ethanol, an increasingly common component of U.S. gasoline, producers use yeast to break down its sugars and ferment corn. The distillation process takes place in large vats of warm water, creating the perfect breeding ground for bacteria that could hamper ethanol yields. To counteract this, the report says that ethanol producers have routinely added antibiotics like penicillin and erythromycin to the fermentation tanks. "These antibiotics, distributed by animal drug manufacturers and chemical suppliers, are readily available without a prescription," according to the report. In fact, they're completely unregulated by the Food and Drug Administration, the same agency under fire for failing to curtail overuse of antibiotics in farming.

So what does creating ethanol have to do with farm animals? The corn mash and liquid slurry by-products created during ethanol production are sold as animal feed. The beef and dairy industry are the biggest consumers of the ethanol by-product - based feed. "Residues of antibiotics in [ethanol-based feed] - the predictable result of adding antibiotics to ethanol fermentation vats - have the potential to cause increased antibiotic resistance, impacting the human population," the author of the report writes.

Don't Buy Into This Dangerous Style of Farming

Until government agencies take action to ban antibiotic use in animal feed, including ethanol by-product feeds, opt for organic, grass-fed dairy and beef. Cows' digestive systems aren't built for a corn diet, anyway, so supporting grass-fed operations means you're supporting healthier cows boasting more nutrients, too. To learn more, read The Guide to Buying Grass-Fed Beef.