In addition,it is common practice to reduce dietary levels of inorganic P, Ca, Na, energy, and some digestible amino acids (phytase matrix) in phytase-supplemented diets. It would seem that supplementation of phytase to diets that already meet birds’ requirements for these minerals can be both wasteful and counterproductive. However, supplementation of phytase at high levels , or to diets that already meet nutrient requirements of broilers, has produced improvement in animal performance presumably via mitigation of anti nutritive effects of phytate rather than supply of limiting nutrients