This document discusses various types of feed additives and their uses. It defines feed additives as ingredients added to basic feed mixes in small amounts to fulfill specific needs. The FDA regulates their use and new additives require clearance. Additives are used to alter animal metabolism, growth, digestion and more. Major classes include growth promoters, medicines, hormones, antioxidants and preservatives. Specific additives mentioned include antibiotics, coccidiostats, hormones, flavors, enzymes and more. All require careful handling and use according to label for safety and effectiveness.