Effects of Supplemental Dietary Phytase on Performance and Blood Biochemical Parameter of Broiler Chicks

Abstract

An experiment was conducted to study the effects of phytase enzyme on performance, blood biochemical parameter and tibia ash content of broiler chicks. Two hundred eighty Ross broiler chicks were located randomly to seven experimental diets at four replicates (cages) and fed from 5 to 28 days of age. A positive control diet (0.422% non-Phytate Phosphorus, nPP) and a negative control diet (0.316% nPP) were used, and five more diets were manufactured by supplementing the negative control diet with 300, 600, 1,200, 2,400, and 24,000 FTU/kg of exogenous phytase (Phyzyme XP). The addition of exogenous phytase above 600 FTU/kg and 1200 FTU/kg improved (P<0.05) feed conversion ratio and body weight gain of the birds fed the negative control diet, respectively. Decreasing nPP content in the diet reduced tibia ash (P<0.001) content and phytase supplementation increased it (P<0.001) as logarithmic liner equation. Phosphorus concentration of serum chicks fed negative control diet was reduced and phytase supplementation above 600 FTU/kg increased it. However, negative control diet increased alkaline phosphatase activity of serum and addition of phytase above 2400 FTU/kg reduced its activity to level of positive control diet (P<0.01). Albumin concentration of serum chicks was increased by addition of phytase above 600 FTU/kg diet. The lowest calcium content and highest total protein concentration of serum chicks were seen at treatment of 600 FTU/kg phytase. These results demonstrated that addition of 600 FTU/kg phytase to low-available phosphorus diets (75% of NRC recommended) improved performance of broiler chicks due to improve utilization of phytate phosphorus of corn-soy bean meal diets.