Effect of Supplementing Phytase at Different Dietary Noe-phytate Phosphorus Levels on the Performance of Broilers

Effect of supplementing phytase at different dietary non phytate phosphorus (NPP) levels on growth and carcass traits of broilers was studied on one hundred ninety two sexed Cobb broilers of one week age, distributed into twelve groups of sixteen birds each. Six isocaloric and isonitrogenous diets were formulated at constant calcium level of 1% with varying levels (0.3,0.4 and 0.5% of NPP without and with phytase 600 units/kg were formulated to duplicate groups so chicks for four weeks. Average body weight, gain in body weight and feed consumption during 1 to 3 weeks of age, were significantly (P≤0.05) affected. However, during 4–5 weeks, the feed consumption was not affected by the dietary treatments. Average body weight and weight gain during 4–5 weeks of age were also significantly (P≤0.05) affected by the addition of phytase. Feed conversion ratio improved at all the NPP levels with the addition of phytase. During entire growth period (1–5 weeks), gain in weight increased with the addition of phytase at all the NPP levels. The addition of phytase at 0.4% NPP increased both feed consumption and feed conversion ratio significantly (P≤0.05) but reverse was true at 0.3% and 0.5% dietary NPP levels. The metabolizability of dry matter, ether extract and nitrogen retention were also significantly (P≤0.05) affected by the supplementation of phytase in the diet Dressing percentage, shank, liver and gizzard weights were significantly (P≤0.05) affected by the supplementation of phytase. The dressing percentage increased with supplementation of phytase at 0.3% and 0.4% NPP levels. It can be concluded that supplementation of 600 units phytase/kg diet improved the performance of the birds.