From the Union of Concerned Scientists website (http://www.ucsusa.org/food_and_agriculture/feed/feed-latest.html#2):
Switch to organic poultry farming reduces antibiotic resistance A blockbuster new scientific study shows that a transition to organic animal production methods that don’t use antibiotics can reduce levels of antibiotic-resistant bacteria on farms. This is the first U.S. study to provide on-farm data on the impacts of removing antibiotics from large-scale poultry CAFOs (confined animal feeding operations). Researchers from the University of Maryland and the Food and Drug Administration measured levels of antibiotic-resistant bacteria in poultry litter, water, and feed samples from 10 conventional poultry operations and 10 newly-organic operations of similar size. (Under organic certification rules, producers are not allowed to use antibiotics.) The newly antibiotic-free organic farms had much lower rates of resistant bacteria compared to the conventional farms, demonstrating that the reduction in antibiotic use can immediately lower the levels of antibiotic-resistant bacteria found on the farm. The study was released in the midst of a massive food safety recall of ground turkey contaminated with antibiotic-resistant salmonella. That incident, involving 36 million pounds of ground turkey produced by agribusiness giant Cargill, sickened some 111 consumers. Read the full study here, and learn more about the turkey recall here.