Effect of phytase supplementation on broiler performance

Two experiments were conducted to study the effects of phytase on the performance of broilers fed maize-soya diets. In experiment I, two diets were used: (i) a reference diet and (ii) a phytase (Biofeed phytase) supplemented diet at 500 FTU/kg feed replacing 6.75 g DCP (0.126% NPP) in starter (0–21 d) and 5.5 g DCP (0.102% NPP) in finisher (22–42 d) diets respectively. Each diet had 8 replicates each with 8 chicks. In experiment II. birds were reared on broiler starter diet up to 22 d and from 23 d onwards three diets were fed: (i) a broiler finisher reference diet (ii) phytase I diet containing phytase at 500 FTU/Kg feed replacing 7g DCP/Kg (0.131% NPP) and (iii) Phytase 2 diet containing phytase at 787 FTU/kg feed replacing II g DCP/kg (0.205% NPP). Each diet had 7 replicates and each replicate had 5 chicks. At 44 d age blood samples from wing vein and tibia from slaughtered bird were collected (one bird from each replicate) for estimating serum Ca and P and tibia ash. The weight gain in broilers fed diets supplemented with phytase at 500 FTU/kg at the expense of 0.126% NPP in starter and 0.131% NPP in finisher diets was similar to that of reference diet. However, supplementing phytase at 787 FTU/kg feed at the expense of 0.205% NPP resulted in a significant (P<0.01) depression in weight gain, tibia ash content and an increase in serum calcium levels. In both the experiments, no significant differences (P>0.05) in carcass traits were observed. It can be concluded that phytase at 500 FTU/kg diet can replace 0.126%NPP (6.75 g DCP/kg) in starter and 0.131% NPP (7g DCP/Kg) in broiler finisher diet.