title: Energy and nutrient utilization of broiler chickens fed corn-soybean meal and corn-based diets supplemented with xylanase.
abstract: A study was conducted to evaluate the effects of increased levels of a β-xylanase on energy and nutrient utilization of broiler chickens fed corn-soy diets. A total of 480 slow feathering Cobb × Cobb 500 male broilers were randomly distributed to 10 treatments having 8 replicates of 6 birds each. Birds were fed a common starter diet to d 14 post hatch (3,050 kcal/kg AMEn, 21.7% CP, 1.05% Ca, and 0.53% nPP). The experimental diets were provided afterwards until 25 d. Two experimental diets, a conventional corn/soy-based basal diet (CS) and the basal diet in which 40% of the diet was displaced by corn (CN), were fed as-is or supplemented with 50, 100, 150, or 200 fungal β-xylanase units (FXU)/kg. Dietary treatments were distributed factorially as a 2 × 5 arrangement. Samples of feed, excreta, and ileal digesta were analyzed for determination of ileal digestible energy (IDE), metabolizable energy, and total tract retention of protein and lipid. No interactions between diet and xylanase were observed. The CS diets had higher (P < 0.05) energy utilization and nutrient digestibility when compared to the CN diets. AMEn and IDE were improved (P < 0.05) by 192 and 145 kcal/kg, respectively, when diets were supplemented with 100 FXU/kg xylanase. The xylanase added to the CN diet led to quadratic increases (P < 0.05) in IDE (Y = - 0.014x(2) + 2.570x + 3,155; r(2) = 0.60) and in AMEn (Y = - 0.016x(2) + 3.982x + 3,155; r(2) = 0.68). Crude protein digestibility and AMEn were linearly increased (P < 0.05) when xylanase was added to the CN diet. In conclusion, energy utilization and digestibility of crude protein and dry matter increased with xylanase supplementation in corn/soy-based diets. When xylanase was tested in the CS diet, 92 and 124 FXU/kg maximized the energy release effect; however, the maximum energy response in the CN diet or corn was not achieved until 200 FXU/kg.
authors.affiliation: Departament of Animal Science, Federal University of Rio Grande do Sul, Av. Bento Gonçalves, 7712, Porto Alegre, RS, Brazil, 91540-000.
authors.forename: C
authors.initials: C
authors.lastname: Stefanello
authors.affiliation: Departament of Animal Science, Federal University of Rio Grande do Sul, Av. Bento Gonçalves, 7712, Porto Alegre, RS, Brazil, 91540-000 slvieira@ufrgs.br.
authors.forename: S L
authors.initials: SL
authors.lastname: Vieira
authors.affiliation: Departament of Animal Science, Federal University of Rio Grande do Sul, Av. Bento Gonçalves, 7712, Porto Alegre, RS, Brazil, 91540-000.
authors.forename: P S
authors.initials: PS
authors.lastname: Carvalho
authors.affiliation: DSM Nutritional Products, Av. Engº Billings, 1729, São Paulo, SP, Brazil, 05321-010.
authors.forename: J O B
authors.initials: JO
authors.lastname: Sorbara
authors.affiliation: DSM Nutritional Products, Wurmisweg 576, 4303 Kaiseraugst, Switzerland.
authors.forename: A J
authors.initials: AJ
authors.lastname: Cowieson
mesh_terms: D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena / Q000187:drug effects / Q000502:physiology; D000818:Animals; D002645:Chickens / Q000378:metabolism*; D004032:Diet / Q000662:veterinary; D019587:Dietary Supplements; D043364:Endo-1,4-beta Xylanases / Q000494:pharmacology*; D004734:Energy Metabolism / Q000187:drug effects / Q000502:physiology; D008297:Male; D013025:Glycine max; D003313:Zea mays
chemical_list: D043364:Endo-1,4-beta Xylanases
keywords: broiler; corn; digestibility; metabolizable energy; xylanase