While animals are a very natural part of the environment, there is nothing natural about raising cattle, chickens or pigs in America today. First comes the billions of pounds of polluting and genetically modified corn and soybeans that are fed to these animals. Each animal is different, but it generally takes from 2 to 9 pounds of food to produce a pound of animal flesh. That food could feed people instead and leave more farmland free for forests and wildlife. Then comes the billions of pounds of manure that is smelly, toxic and poorly regulated . Every city in America has a large staff of people dedicated to treating sewage and runoff to protect people and the environment, and there are many strictly enforced regulations for sewage treatment. Yet large chicken, pork and cattle operations often do not treat their sewage at all. The 2014 movie Cowspiracy very eloquently summarizes the environmental challenges created by the meat industry.