Comparative Effect of Microbial Phytase Supplementation on Layer Chickens Fed Diets with Required or Reduced Phosphorous Level

Abstract

An experiment was conducted to determinethe effect of microbial phytase supplementation on layer`s feed. One hundred and sixteen 23-week-old Lohman brown laying hens were used in a 8-weeks feeding trial. Hens were randomly allotted into four treatments where the group (1) (control group) was fed basal diet with normal non-phytate phosphorous (0.38%) without phytase, group (2) fed diet with normal NNP (0.38%) and supplemented with phytase, group (3) fed diet with NNP 0.32% and supplemented with phytase enzyme and group (4) fed diet with NNP 0.26% and supplemented with phytase. Results revealedthat egg weight showed significant (p<0.05) increasein all phytase supplemented groups. Egg shell weight increasedsignificantly (p<0.05)in all phyatse supplemented groups when compared with the control group also shell thickness increased significantly (p<0.05) in both group (2 &3). No significant (P≥0.05) difference was observed in serum Ca,P level while alkaline phosphatase was significantly (P˂0.05) increased in group (3). Egg shell analysis showed increase in egg shell ashand  egg shell calcium % % in group (3) and group (4) when compared with the control group. Egg shell phosphorous% was higher in all phytase supplemented groups than the control group.Dietary 0.26% NNP level supplemented with phytase enzyme significantly (p<0.05) increase Ca availability. Also dietary 0.32% and 0.26% NNP level supplemented with phytase enzyme significantly increase (p<0.05) P availability by 33.85% and 20.7%.  Phytase supplementation in laying hens ration is not recommended without reduction of dietary NNP.