Effect of sequential feeding of phosphorus-deficient diets and high-dose phytase on efficient phosphorus utilization in broiler chickens

Abstract

ABSTRACT An experiment was conducted to investigate the effectiveness of sequential feeding of a very low non-phytate P (NPP) diet supplemented with varying doses of phytase to broiler chickens. A total of 450 one-day-old male broiler chickens were fed a standard diet up to 14 d of age, then allotted to 6 dietary treatments (with 5 replicates of 15 broiler chickens each) from d 14 to 42. Dietary treatments included a positive control [PC; 4.35 g NPP/kg (d 14 to 28) and 3.95 g NPP/kg (d 28 to 42)], a negative control without any inorganic P source [NC; 1.50 g NPP/kg (d 14 to 28) and 1.36 g NPP/kg (d 28 to 42)], and a negative-positive control (NPC), in which broiler chickens received the PC for 24 h and then fed the NC (including 0, 500, 1,500, or 3,000 FTU phytase/kg) for the following day in a 48-h-cycle sequential feeding program. The Ca to NPP ratio was maintained at 2 to 1 in all formulations. The NC diet decreased overall feed intake (FI) and serum P compared to those of the PC diet (P = 0.047 for overall FI; P