title: Effects of exogenous proteases without or with carbohydrases on nutrient digestibility and disappearance of non-starch polysaccharides in broiler chickens.
abstract: The objective of the current study was to evaluate the effect of a subtilisin protease, without or with inclusion of carbohydrases, on digestibility and retention of energy and protein, as well as the solubilization and disappearance of non-starch polysaccharides (NSP) from corn-soybean meal based diets fed to broiler chickens. Two hundred eighty-eight Ross 308 male broiler chickens were used for the experiment. On d 14, the birds were weighed and allocated to 6 treatments and 8 replicates per treatment with 6 birds per replicate. Treatments were: 1) corn-soybean meal based control diet; 2) control diet plus supplemental protease at 5,000 (P5000) protease units (PU)/kg); 3) control plus 10,000 PU/kg protease (P10000); or control plus an enzyme combination containing xylanase, amylase, and protease (XAP) added to achieve protease activity of: 4) 2,500 PU/kg (XAP2500); 5) 5,000 PU/kg (XAP5000); or 6) 10,000 PU/kg (XAP10000). The enzymes in XAP were combined at fixed ratios of 10:1:25 of xylanase:amylase:protease. Data were analyzed by ANOVA and specific orthogonal contrasts between treatments were performed. Addition of xylanase and amylase increased (P < 0.05) the ileal digestibility of protein by 4.2% and 2.1% at XAP5000 and XAP10000, respectively (relative to P5000 and P10000, respectively), exhibiting a plateau after the XAP5000 dose. Increment (P < 0.05) in AME due to protease was evident, particularly in P10000. At the ileal level, XAP reduced (P < 0.05) the flow of insoluble xylose and arabinose, which indicates an increase in the solubilization of arabinoxylan polymers in the small intestine. Protease on its own reduced (P < 0.05) the flow of insoluble arabinose but did not affect the flow of insoluble xylose. XAP reduced (P < 0.05) the pre-cecal flow of insoluble and total glucose and galactose. It was concluded that whereas protease by itself improved nutrient utilization and increased solubilization of NSP components, at the lower dose, a combination of xylanase, amylase, and protease produced effects greater than those of protease alone.
authors.affiliation: Monogastric Science Research Centre, Scotland's Rural College, Edinburgh, EH9 3JG, UK oluyinka.olukosi@sruc.ac.uk.
authors.forename: O A
authors.initials: OA
authors.lastname: Olukosi
authors.affiliation: Monogastric Science Research Centre, Scotland's Rural College, Edinburgh, EH9 3JG, UK.
authors.forename: L A
authors.initials: LA
authors.lastname: Beeson
authors.affiliation: Englyst Carbohydrates Ltd, Southampton, Hampshire, SO16 7NP, UK.
authors.forename: K
authors.initials: K
authors.lastname: Englyst
authors.affiliation: Dupont Industrial Biosciences, Marlborough, SN8 1XN, UK.
authors.forename: L F
authors.initials: LF
authors.lastname: Romero
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000824:Animal Nutritional Physiological Phenomena / Q000187:drug effects; D000818:Animals; D002645:Chickens / Q000502:physiology*; D004032:Diet / Q000662:veterinary; D004044:Dietary Proteins / Q000378:metabolism*; D019587:Dietary Supplements / Q000032:analysis; D004063:Digestion / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004734:Energy Metabolism / Q000187:drug effects*; D006026:Glycoside Hydrolases / Q000378:metabolism*; D007082:Ileum / Q000502:physiology; D008297:Male; D011134:Polysaccharides / Q000378:metabolism*; D013025:Glycine max / Q000737:chemistry; D020860:Subtilisin / Q000008:administration & dosage / Q000494:pharmacology*; D003313:Zea mays / Q000737:chemistry
chemical_list: D004044:Dietary Proteins; D011134:Polysaccharides; D006026:Glycoside Hydrolases; C019822:carbohydrase; D020860:Subtilisin
keywords: broilers; carbohydrase; component sugars; non-starch polysaccharides; protease