Effect of dietary phytase and high available phosphorus corn on broiler chicken performance

Two trials were conducted to determine the effects on broiler chicken performance and health of reducing dietary phosphorus levels by treating feed with the enzyme phytase, formulating diets using high available phosphorus (HAP) corn, or when diets were formulated with HAP corn and treated with phytase. Cobb x Cobb male broiler chickens were placed in an experimental design consisting of four dietary treatments with six replicate pens of 50 broilers per pen. The dietary treatments consisted of untreated control feed, phytase-supplemented feed (500 U/kg), diets prepared with HAP corn, and diets prepared with HAP corn and supplemented with phytase. The chickens were maintained on these dietary treatments from 1 to 49 d of age with feed and water made available for ad libitum consumption. When the two trials were combined, there was a significant (P < or = 0.05) increase in body weight in the broilers fed the phytase treated diets at 49 d of age. The serum activity of alkaline phosphatase was significantly decreased in the diets supplemented with phytase, and serum cholesterol was significantly decreased in the diets prepared with HAP corn. These data indicate that total phosphorus can be reduced by at least 11% in diets prepared with HAP corn, or in diets supplemented with phytase, without affecting the performance or health of broiler chickens. When diets are prepared with HAP corn and supplemented with phytase, the dietary addition of total phosphorus can be reduced by at least 25% without affecting broiler chicken performance or health.