Maryn McKenna chased the medical mystery of drug-resistant infections right to the source: industrial chicken farms.
Americans love their chicken, and last year, they each ate a record-breaking 91 pounds of it, whether in the form of Chicken McNuggets, chicken salad, Kentucky Fried Chicken, or chicken soup (for the soul, anybody?). But as Maryn McKenna lays out in her new book “Big Chicken: The Incredible Story of How Antibiotics Created Modern Agriculture and Changed the Way the World Eats,” the secret story of chicken’s success may have more to do with antibiotics than white meat. These days, as McKenna points out, birds are produced much like factory cars — and in low doses, added to feed or water, antibiotics fatten up chickens and protect them from infections due to overcrowding.
Today, a chicken’s weight at slaughter is twice what it was 70 years ago, and it’s achieved in half the time. To help them get there, chickens — along with other animals in the U.S. — consume 34 million pounds of antimicrobials per year including antibiotics, very little of it to cure actual infections. (For comparison, in 2011, about 8 million pounds of antibiotics were sold to humans.) As much as 80% of the antibiotics sold in the U.S. are given to animals; all those drugs weigh in at more than 63,000 tons per year, according to a 2010 paper.