Effect of a new coating on the bioefficacy of a phytase product in broilers fed corn-soybean meal- based diets

A study evaluated whether a coated (C) bacterially-derived, non-intrinsically thermostable, phytase product showed equivalent bioefficacy compared to the uncoated version of the same product (Phyzyme XP; 6-phytase, EC 3.1.3.26). Male Ross 308 chicks were assigned to three dietary treatments each with 6 cage replicates of 8 birds each The treatments were: Control (NC), NC + 500 U/kg phytase and NC + 500 U/kg C-phytase. Except for Ca and P, the basal corn-soybean meal diet was formulated to meet NRC (1994) requirement. Calcium and P levels were 0.58 and 0.22%, respectively. Birds were weighed on days 0 and 21, and on day 21 birds were sacrificed for ileal phosphorus digestibility and tibia ash determination. Data were analysed using the GLM procedure of SAS. No significant differences were observed between the two phytase treatments. Supplementation of the NC diet with phytase and C-phytase increased (P<0.05) tibia ash from 45.9% to 49.2% and 49.1%, respectively. There were no significant differences between treatments for 21-d body weight (P>0.05). Phosphorus digestibility significantly improved by 20.6 and 18.0 percentage units (P<0.05) with phytase and C-phytase supplementation, respectively. Addition of the new coating to the phytase resulted in similar bioefficacy to the original uncoated product.