Effect of nonphytate phosphorus and phytase levels on broiler tibia

Abstract

It was evaluated the effect of nonphytate phosphorus (NNP) and phytase on broiler tibia.One thousand and two hundred chicks were allocated in a completely randomized designand factorial arrangement 4 x 3 (NPP x phytase levels), with four replicates. NPP levels, ateach phase, were 0.45, 0.37, 0.29 and 0.21% - initial, 0.41, 0.33, 0.25 and 0.17% - growth,and 0.37, 0.29, 0.21 and 0.13% - withdrawal. Phytase levels were 0, 500 and 1000 FTU/kgof diet. There was no effect on diameter at 21 days of age. Tibia with lower weight, lengthand diaphysis, distal epiphysis and average densities e proximal epiphysis density resultedfrom NPP reduction from 0.37 to 0.29% and from 0.29 to 0.21%, respectively. Inclusion of500 FTU/kg of phytase improved length and diaphysis density of the tibia, independent ofNPP levels. Diets with NPP, at initial, growth and final phases, of 0.37, 0.33 and 0.29%,respectively, supplemented with 1000 FTU/kg of phytase, can be used with no negativeeffect on bone quality in broilers.