A new study of chicken farms confirms a long-suspected benefit of organic agriculture: it fights the spread of antibiotic-resistant bacteria. For years, scientists have had a hunch that the widespread use of antibiotics on livestock encouraged naturally-occurring microbes to develop resistance to drugs. But antibiotics are so common on American farms that their hypothesis was hard to test.
The new study, headed by Amy Sapkota of the University of Maryland and published in Environmental Health Perspectives, tested the microbes present in 10 conventional chicken farms and 10 chicken farms that had recently gone organic. Organic standards do not allow the use of preventative antibiotics in animals, so if the researchers' hypothesis was right, they would find lower levels of drug resistance in the bacteria there.
The researchers findings were definitive. A much smaller percentage of the bacteria at the organic farms had antibiotic resistance -- indicating that the use of antibiotics in animals encourages the spread of drug resistant bacteria.
Non-therapeutic antibiotics are banned at livestock farms in most of Europe; could American regulators follow suit? This study is the latest in a string of studies finding that organic agriculture supports good health.
The meat industry, though, continues to dispute the link between its use of antibiotics and the growth of drug-resistant bacteria. And low doses of antibiotics allow industrial livestock farmers to cram more animals into a smaller space and have them grow faster.
That said, antibiotic use, and the drug-resistant bacteria it encourages, is starting to take a chunk out of meat producers' bottom line. Just last week, Cargill recalled 36 million pounds of ground turkey because it was thought to be tainted with drug-resistant salmonella.