Since the end of the Second World War, the United States has pursued a national policy of an abundant and inexpensive food supply. Increased animal productivity has improved efficiencies of animal production and reduced the carbon footprint for production of meat, milk, and eggs. Some components of the technologies employed by animal producers to improve efficiency of animal production include improved nutrition and reproduction; advances in genetics; and health and management practices; as well as feed additives, hormonal treatments, and growth enhancing technologies (GETs).