Phosphorus requirements of broiler chicks six to nine weeks of age as influenced by phytase supplementation.

摘要: Two trials of similar design were conducted to determine the nonphytate phosphorus (NPP) requirements for broilers from 42 63 d age in diets with or without phytase supplementation. Male a commercial strain grown on nutritionally complete NRC (1994) recommended levels Ca and NPP. At d, birds placed experimental fed d. The treatments consisted 2 x 6 factorial arrangement two (0 800 U/kg) six NPP (0.10 0.35% 0.05% increments). Body weight gain, feed conversion, mortality determined during period. 49, 56, excreta samples taken, killed tibia ash determination. lowest level NPP, supplementation, was sufficient maximum BW livability. Using nonlinear regression, needed optimize absence 0.31 +/- 0.004%, 0.23 0.02%, 0.22 0.029% at respectively. When supplemented U/kg phytase, requirement optimum 0.15 0.049% 49 56 no more than 0.10% (lowest tested) maximize ash. Compared current recommendations, application these reduced dietary could markedly reduce excretion by broilers.