ABSTRACT
This chapter highlights the use of feed additives in animal production and the underlying mechanisms of actions, and to outlines those conditions where their inclusion in diets is most likely to result in beneficial effects. By reducing the availability of dietary phosphorus and other nutrients, phytate has considerable anti-nutritive effects for animals and increases their requirements for dietary nutrients. In animals, the sources of phytase for phytate digestion may be endogenous mucosae, gut microflora, plant ingredients, and exogenous phytase preparations. As early as the 1950s, concern was expressed that continued use of antibiotics to promote growth of poultry and other food animals might result in antibiotic resistance of pathogenic bacteria in humans. An important advance in animal nutrition over the past five decades is the use of feed additives to improve livestock, poultry, and fish growth and feed efficiency. An improvement in the growth performance and feed efficiency of animals will generate significant economic returns to producers.
