title: The effect of thermal processing and enzyme treatments of soybean meal on growth performance, ileal nutrient digestibilities, and chyme characteristics in broiler chicks.
abstract: Effects of thermal processing (toasting or extrusion) of untoasted soybean meal on growth performance, apparent ileal nutrient digestibilities, and chyme characteristics were studied in broiler chicks fed diets with soybean meal as the main protein source. Effects of increasing shear forces during extrusion as well as enzyme treatments (protease and carbohydrase) were also studied. When compared with toasting, extrusion significantly improved feed conversion ratio (1.56 vs 1.62) and apparent ileal digestibilities of CP and nonstarch polysaccharides (87.5 vs 82.2% and 26.7 vs 11.4%, respectively). Enzyme treatment improved apparent ileal digestibility of CP and nonstarch polysaccharide compared with no enzyme treatment (85.2 vs 83.7% and 20.6 vs 14.5%, respectively); however, enzyme treatments did not result in a better growth performance of the chicks. Among the enzyme treatments, no differences were found in growth performance and apparent ileal CP digestibility, whereas the carbohydrase significantly improved apparent ileal nonstarch polysaccharide digestibility compared with the other enzyme treatments. Extrusion of SBM at the highest shear level caused a significant increase in the water-holding capacity, chyme viscosity, and concentration of soluble nonstarch polysaccharides in the chyme compared with extrusion of SBM at lower shear levels. The increase in chyme viscosity did not affect growth performance, nor did it influence apparent ileal nutrient digestibilities.
authors.affiliation: Wageningen Agricultural University, Department of Food Science, The Netherlands.
authors.forename: G J
authors.initials: GJ
authors.lastname: Marsman
authors.forename: H
authors.initials: H
authors.lastname: Gruppen
authors.forename: A F
authors.initials: AF
authors.lastname: van der Poel
authors.forename: R P
authors.initials: RP
authors.lastname: Kwakkel
authors.forename: M W
authors.initials: MW
authors.lastname: Verstegen
authors.forename: A G
authors.initials: AG
authors.lastname: Voragen
mesh_terms: D000818:Animals; D001835:Body Weight / Q000502:physiology; D002473:Cell Wall / Q000378:metabolism; D002645:Chickens / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D004044:Dietary Proteins / Q000378:metabolism; D004063:Digestion / Q000502:physiology; D010450:Endopeptidases / Q000494:pharmacology*; D005260:Female; D005511:Food Handling / Q000379:methods*; D006026:Glycoside Hydrolases / Q000494:pharmacology*; D006358:Hot Temperature; D007082:Ileum / Q000737:chemistry / Q000378:metabolism* / Q000502:physiology; D011134:Polysaccharides / Q000378:metabolism; D013025:Glycine max / Q000592:standards*; D014783:Viscosity
chemical_list: D004044:Dietary Proteins; D011134:Polysaccharides; D006026:Glycoside Hydrolases; C019822:carbohydrase; D010450:Endopeptidases