Farm animals are routinely given low levels of antibiotics—to prevent disease, to help them grow bigger and to hedge against the difficult conditions of factory farming—and this widespread practice is contributing to the steady rise of antibiotic resistance in bacteria, scientists think. Some diseases can hop back and forth between humans and farm animals, and the low doses of antibiotics allow bacteria to evolve defenses, before they jump back to humans. (This video from the American Museum of Natural History does a good job explaining the basics.)

This problem has been on a lot of researchers' radars for a very long time, at least back to the 1970s, says the New York Times, and now the Food and Drug Administration is taking steps to do something about it. Over the next three years, the federal agency wants to eliminate the use of antibiotics as a growth promoter.

The problem with the plan, says journalist Maryn McKenna for her blog, Superbug, is that it isn't mandatory. But, the FDA does have the power to do a fair bit of naming and shaming, which should hopefully help encourage its adoption:

Companies have 90 days to signal to the FDA whether they agree to follow this plan. Could they defy the agency and continue to sell their products for growth promotion? Probably they could; but the FDA has promised to make transparent which companies sign up and don’t, apparently counting on public pressure to get companies to move.

The move won't end the use of antibiotics on farms. They'll still be available for treating, or in some cases, preventing, diseases. But if the FDA's plan gets widespread adoption, it should hopefully cut down the routine use of low doses of antibiotics that is thought to be the issue when it comes to antibiotic resistance.

More from Smithsonian.com:

What Will It Take to Wipe Out Superbugs?

Your Meat is Probably Packing Antibiotic Resistant Superbugs