Perdue Farms uses antibiotics in attempts to keep their chickens healthy.
The living conditions, the spread of sicknesses and diseases from overcrowding, and the inhumane treatment the chickens receive all play a role.
Living conditions are cramped, with birds numbering in the thousands. They are also incredibly filthy, being ridden with waste, as well as corpses of perished birds, and ventilated. Antibiotics are used by Perdue to keep most of the chickens from dying due to environmental induced sicknesses.