The European Union banned the use of antibiotics to boost animals' growth in 2006. At first, the ban had little effect on the amount of drugs given to pigs. Carsten Rehder/Corbis hide caption

itoggle caption Carsten Rehder/Corbis

Craig Rowles tends to his pigs in a barn near Carroll, Iowa. Dan Charles/NPR hide caption

itoggle caption Dan Charles/NPR

Organic apples hang from trees in an orchard in Forest Range, Adelaide Hills, South Australia. donkeycart/via Flickr hide caption

itoggle caption donkeycart/via Flickr