Enhancing nutrient utilization of broiler chickens through supplemental enzymes

Abstract

The objective was to determine effects of adding phytase, amylase, and a cocktail of non-starch polysaccharide-degrading enzymes (NSPase) individually or in combinations to corn-soybean meal-based diet for broilers on apparent ileal digestibility (AID) of nutrients and dietary AMEn value. Four hundred and eighty male broiler chicks were divided into 80 groups and fed 8 diets in a completely randomized design (10 groups/diet) from day 15 to 21 of age. The diets were basal diet unsupplemented or supplemented with phytase (1,500 FTU/kg; Ronozyme HiPhos), amylase (80 KNU/kg, Ronozyme HiStarch), and NSPase (75g/metric ton, Ronozyme Multigrain) individually or in all possible combinations. The basal diet contained the phytase at 1,000 FTU/kg, and was formulated to meet the NRC (1994) recommended nutrient requirements for broiler chickens except for ME, Ca, and non-phytate P, which were reduced by 150kcal/kg, 0.18%, and 0.15%, respectively. Addition of phytase to the basal diet increased (P < 0.05) AID of P from 40.4 to 59.3%. Addition of amylase, NSPase or a combination of amylase and NSPase to the phytase-supplemented basal diet further increased (P < 0.05) AID of P to 63.4, 69.9, and 67.3%, respectively. Addition of phytase, amylase or a combination of amylase and NSPase to the basal diet did not affect dietary AMEn value. However, addition of NSPase alone or a combination of phytase and amylase or of phytase and NSPase to the basal diet improved (P < 0.05) dietary AMEn value from 3,203 to 3,339, 3,309 or 3,289kcal/kg, respectively. In conclusion, it is more beneficial (with regard to AID of P and dietary AMEn) to add amylase and NSPase to phytase-supplemented diets for broilers. Because the basal diet contained phytase at 1,000 FTU/kg, the increase in AID of P due to supplemental phytase (1,500 FTU/kg) indicates that supplemental phytase at 2,500 FTU/kg is more beneficial with regard to improving AID of P than supplemental phytase at 1,000 FTU/kg.