Effect of microbial phytase on production performance of White Leghorn layers fed low non-phytate phosphorus diet
A.K.PANDA, S. V. RAMA RAO AND M. V.L. N. RAJU
Project Directorate on Poultry
Rajendranagar, Hyderabad , - 500 030
An experiment with 150 WL layers was conducted to examine the effect of microbial phytase supplementation to low NPP diets on their egg production, egg shell quality, bone mineralisation and retention of nutrients during 32 to 48 weeks of age. Four isonitrogenous and isocaloric diets were formulated to contain 1.2, 1.8, 2.4 and 3.0 g NPP/kg diet with the two lowest NPP (1.2 and 1.8) supplemented with microbial phytase ( Biofeed Phytase, India) @ 500 FTU per kg diet. Each diet was offered ad libtum to 5 replicates of 5 layers in each throughout the experiment. The body weight gain lowered significantly (P<0.05) in the layers fed 0.12 % NPP diet as compared to those fed higher levels of NPP (0.18 to 0.30 %). Supplementation of phytase to 0.12 % NPP diet significantly enhanced the body weight and was comparable with those fed diet containing 0.18 to 0.30 % NPP. No additional advantage could, however, be found by enhancing the NPP levels beyond 0.18 % (0.24 or 0.30 %) or supplementing phytase to diet containing 0.18 % NPP. The hen day egg production, food intake, food efficiency, shell weight, shell thickness, shell strength and tibia strength followed the same trend as above. However, supplementing phytase to 0.18 % NPP diet significantly enhanced the tibia ash content than without phytase supplement. Egg weight, specific gravity and haugh unit was neither influenced by NPP levels nor due to phytase supplementation. Supplementing phytase to 0.12 % NPP diet significantly (P<0.05) enhanced not only the retention of N and P but also reduced their excretion. It could be concluded that supplementation of 500 FTU of microbial phytase / kg diet can reduce the NPP level to 0.12 % in the layer diet, eliminates inorganic P supplementation and resulted in significant reduction of N 2 and P excretion without affecting the production performance of layers.