Performance of WLH starter chicks fed different levels of phytase at varying non phytate phosphorus levels.

An experiment using 3x3 factorial design was conducted on week old egg type starter chicks to see the effect of different levels of non-phytate phosphorus (NPP) at different levels of enzyme phytase. Eighteen groups of thirty chicks in each were constituted. The average weight between and among the different groups was kept similar. Nine experimental diets with 0.2, 0.3 and 0.4% NPP levels at 400, 500, 600 units of phytase/kg diets were formulated. Each diet was randomly allocated to a duplicate group of chicks. The feeding was done ad lib up to eight weeks of age. Dietary NPP levels significantly (P<0.01) affected the body weight, gain in weight, feed consumption and feed conversion ratio. However phytase levels did not significantly (P<0.01) affected the body weight and weight gain but both the feed consumption and feed conversion efficiency were significantly (P<0.05) affected by the different levels of enzyme irrespective of dietary NPP levels. Increase in enzyme level at 0.2% NPP level significantly (P<0.05) reduced the body weight, weight gain and feed consumption with deterioration in FCR. However at 0.3% NPP level, increase in enzyme level significantly (P<0.05) improved weight gain and feed consumption. On the other hand at each level of enzyme, increase in dietary NPP level significantly (P<0.05) improved the body weight and gain in weight with increase in feed consumption. The data revealed that the highest body weight and gain in weight were achieved at 0.3% NPP with 500 units of phytase followed by the diet with 0.4% NPP with 400 unit of phytase.