Impact of exogenous carbohydrases and phytase on growth performance and nutrient digestibility in broilers

Abstract

Lu, H., Adedokun, S. A., Preynat, A., Legrand-Defretin, V., Geraert, P. A., Adeola, O. and Ajuwon, K. M. 2013. Impact of exogenous carbohydrases and phytase on growth performance and nutrient digestibility in broilers. Can. J. Anim. Sci. 93: 243–249. The effect of supplementing corn–soybean-based diets with Rovabio®Max AP, an exogenous enzyme mix with carbohydrase (xylanase and β-glucanase) and phytase activities to broiler chickens was evaluated. Male Ross 708 broilers were assigned to four diets: positive control (PC), negative control (NC), deficient in metabolizable energy (ME), crude protein (CP), calcium (Ca) and non-phytate phosphorus (nPP), relative to the PC, by 100 kcal kg−1, 5 g kg−1, 1.1 g kg−1and 1.6 g kg−1, respectively, in the starter and grower diets; and NC+Rovabio®at 0.05 or 0.075 g kg−1diet. Starter diets were fed from day 0 to day 21 and grower diets from day 22 to day 42. Body weight (BW) and body weight gain on days 22 and 42 were increased (P<0.05) by enzyme supplementation. Enzyme addition increased (P<0.05) feed intake from day 22 to day 42 and overall (day 0 to day 42). Gain to feed ratio (G:F) was significantly increased (P<0.05) with enzyme supplementation during both starter and grower phases. Enzyme addition increased (P<0.05) serum phosphorus (P) concentration on day 21. On day 42 enzyme supplementation increased (P<0.05) the apparent ileal digestibility of P, dry matter (DM), energy, and N. Addition of a combination of carbohydrases (xylanase and β-glucanase) and phytase to corn–soybean-based diets deficient in ME, CP, Ca and P resulted in a significant increase in growth performance and utilization of P, DM, energy and N in broiler chickens.