The cows chew the grass down low enough for hens, then often, though not always, the pigs come in and root the soil, prepping it for its next coat of sod. “We’ll always need animals for food,” says Kirschenmann. “Without them, we’d have no manure. The question is, how many can the landscape bear before it, and the system, fall apart?”

http://www.rollingstone.com/feature/belly-beast-meat-factory-farms-animal-activists