Phytase Superdosing in the Diet of Lightweight Replacement Pullets: Performance, Organ Biometry and Bone Characteristics

ABSTRACT The aim of this study was to evaluate the effect of two types of phytases (the 1st produced from Escherichia coli and the 2nd from Aspergillus oryzae) with different dosages (300 and 900 Unit Phytase or FTU) on performance, organ biometry and bone quality of replacement pullets in the period of 8 to 17 weeks of age. A total of 288 Hy-Line White laying hens were used at 8 weeks of age. A completely randomized design was adopted in a 2 x 2 factorial scheme, totaling 4 treatments with 8 replicates of 9 birds each. Performance, biometric variables and bone characteristics were evaluated. There was no significant interaction between the factors for any of the evaluated variables. The conversion and the accumulated consumption were influenced (p