Effects of Phosphorus Level and Phytase in Broiler Breeder Rearing and Laying Diets on Live Performance and Phosphorus Excretion1

ABSTRACT The effects of a reduced dietary nonphy-tate phosphorus (NPP) level and inclusion of phytase on broiler breeder performance and P concentrations in the litter and manure were investigated. Ross 308 broiler breeder pullets and Ross 344 cockerels were placed sex-separate in a blackout growing house and fed standard starter and grower diets to 9 wk of age. At 10 wk of age, 4 treatments (A, B, C, D) were assigned to each of 4 floor pens of 68 pullets and 1 pen of 50 cockerels. From 10 t