摘要
This study consolidates the efficacy of a non-starch polysaccharide （NSP）ase enzyme-concept in corn and wheat-based broiler diets. The NSP building blocks of corn, wheat and soybean meal （SBM, 44% protein） were studied first. Cereal NSP primarily consists of arabinose, xylose and glucose molecules that form arabinoxylan, β-glucan and cellulose polysaccharides. In soybean meal （SBM）, glucose （cellulose） predominates, next to galactose and uronic acids that form “pectins”. Broiler performance progress using in-feed NSPase enzymes depends on the concentration, complexity and solubility of the substrate and the genetic potential of the animal, mainly. A dual NSPase enzyme-concept for cereal and SBM NSP, predominantly being arabinoxylan, β-glucan and cellulose, was developed. Methods for measuring enzyme activities （endo-1,4-β-xylanase （EC 3.2.1.8） and endo-1,3（4）-β-glucanase （EC 3.2.1.6）） were developed （AVEVE Biochem UNITS） and preparations thereof （XG） standardized to meet requirements for most challenging NSP （corn, barely soluble）. Feed intake （FI）, bodyweight gain （BWG） and feed：gain ratio （F：G） were assessed in three zootechnical studies, each using 160 Ross 308 broilers split in two feeding groups with 80 birds/group （10 replicates of eight） for 42 d （starter/grower period）. Respective corn-SBM, wheat-SBM and corn/wheat-SBM diets were used as negative control （NC） or added with the enzyme-concept （XG）. In the total period, XG ameliorated BWG and F：G compared to NC in each study, where BWG increased best in diets with corn and F：G lowered most in diets with wheat. The dual NSPase enzyme-concept offers ingredient flexibility in present setting by enhancing the nutritional content of corn, wheat and SBM, expectedly from cleaving major NSP target molecules. Thereby, broiler professionals increase feed formulation liberty and safety and production result simultaneously.
