About 80% of antibiotics produced in the U.S. are given to farm animals. This practice is: Bad for Human Health > This overuse of antibiotics encourages the evolution of antibiotic-resistant bacteria strains by giving bacteria resistant to the antibiotics a better chance of survival. > Because the antibiotics we feed animals are similar to those for humans, the evolution of antibiotic-resistant bacteria strains is a serious public health threat. > Poultry products often carry at least one bacterial strain, and it is now increasingly likely that the bacteria in the meat you buy is an antibiotic-resistant strain. Bad for the Environment > Nearly two trillion tons of animal waste are produced each year in America. This waste contains significant amounts of undigested antibiotics and antibiotic-resistant bacteria, which can contaminate surface and ground water, harm natural ecosystems, and eventually make their way back to humans. Bad for Farm Animals > Animals on factory farms are given antibiotics to compensate for their crowded and unsanitary living conditions and to help them gain weight. Livestock allowed to lead more natural lives are healthier and need fewer antibiotics.