In the past few years, with evidence linking antibiotics on animal farms to drug resistance in humans, poultry producers (Perdue, Tyson, etc.) and restaurant chains (McDonald’s, Chick-fil-A, Wendy’s, Burger King, etc.) have pledged en masse to limit antibiotics in their chicken. It’s easy to pledge, but harder to do. The shift has farmers scrambling to break their reliance on antibiotics and find new ways to help their birds grow.