The most significant changes in U.S. food-animal production in decades are coming by the end of this year, and farmers and producers aren’t prepared. That’s the warning of the nonpartisan Farm Foundation, based in Oak Brook, Ill., in a report called Stewardship of Antimicrobial Drug Use in Food-Producing Animals, released Wednesday morning.

The changes will make giving animals low doses of antibiotics to promote growth illegal, and new federal rules will require large-animal veterinarians to start approving antibiotic use. And a shortage of these veterinarians may make implementing the new changes even more challenging, Farm Foundation says.

The foundation released the report during the opening of a two-day summit on livestock antibiotic use Wednesday and Thursday in Washington, D.C. The report is based on a series of 12