体外消化法优化生长猪玉米-豆粕-DDGS饲粮和小麦-豆粕饲粮非淀粉多糖酶谱的研究

Optimization of Non-starch Polysaccharide Enzymes of Corn-Soybean-DDGS and Wheat-Soybean Diets for Growing Pig Using in vitro Method

旨在探讨使用体外法模拟猪饲粮胃肠道消化,优化生长猪玉米-豆粕-DDGS饲粮和小麦-豆粕饲粮的非淀粉多糖(NSP)酶谱。试验首先采用单因素完全随机设计,在玉米-豆粕-DDGS饲粮和小麦-豆粕饲粮中分别添加不同水平的单一NSP酶:纤维素酶、木聚糖酶、β-甘露聚糖酶、α-半乳糖苷酶、β-葡聚糖酶和果胶酶,采用基于生长猪生理消化的模拟胃液-小肠液体外法对饲粮体外干物质消化率(in vitro dry matter digestibility,IVDMD)进行测定,分析各NSP酶对饲粮IVDMD的作用效果。然后采用二次回归通用旋转设计,分别建立两种饲粮IVDMD与6种NSP酶的回归关系,筛选两种饲粮中6种NSP酶的最佳组合,再对优化的酶谱组合进行体外验证。结果显示:1)生长猪玉米-豆粕-DDGS饲粮和小麦-豆粕饲粮的IVDMD与6种NSP酶的添加水平之间均存在二次曲线关系;2)在本试验条件下,玉米-豆粕-DDGS饲粮的最佳酶谱:纤维素酶427.1U·kg^(-1)、木聚糖酶7 057.5U·kg^(-1)、β-甘露聚糖酶3 587.8U·kg^(-1)、α-半乳糖苷酶202.1U·kg^(-1)、β-葡聚糖酶1 543.3U·kg^(-1)和果胶酶72.7U·kg^(-1)。小麦-豆粕饲粮的最佳酶谱:纤维素酶1 117.9 U·kg^(-1)、木聚糖酶35 087.7 U·kg^(-1)、β-甘露聚糖酶1 917.1U·kg^(-1)、α-半乳糖苷酶305.0U·kg^(-1)、β-葡聚糖酶806.7U·kg^(-1)和果胶酶133.7U·kg^(-1);3)优化后的NSP酶谱组合使玉米-豆粕-DDGS饲粮的IVDMD提升了3.89%;使小麦-豆粕饲粮的IVDMD提升了3.48%。结果表明,体外法优化后的NSP酶谱组合和配伍能更大程度地提高生长猪玉米-豆粕-DDGS饲粮和小麦-豆粕饲粮的IVDMD,基于生长猪生理消化的模拟胃液-小肠液体外消化法可快速筛选出生长猪饲粮合理的NSP酶谱。

The study was conducted to optimize non-starch polysaccharide（NSP） enzymes of corn-soybean-DDGS diet and wheat-soybean diet for growing pigs using in vitro method. The NSP enzymes （cellulase, xylanase, β-mannanase, α-galactosidase, β-glucanase and pectinase） were added into the corn-soybean-DDGS diet and the wheat-soybean diet. In a one-way completely randomized experimental design, in vitro dry matter digestibility （IVDMD） of the two diets was determined using the gastric fluid and small intestinal fluid based on physiological data of growing pigs and the dose-response of the NSP enzymes on the IVDMD of diets were analyzed,respectively. Then the regression relationship of 6 NSP enzymes and the IVDMD of diets were established and the optimal NSP enzyme components was screened using a quadratic regress-universal rotary design. The results showed that：1） Quadratic effects of NSP enzymes on the IVDMD of corn-soybean-DDGS and wheat-soybean diets for growing pig were observed in the present study. 2） The optimal NSP enzyme components were 427.1 U·kg-1 cellulase, 7 057.5 U·kg-1 xylanase, 3 587.8 U·kg-1 β-mannanase, 202.1 U·kg-1 α-galactosidase, 1 543.3 U·kg-1 β-glucanase and 72.7 U·kg-1 pectinase for corn-soybean-DDGS diet, and 1 117.9 U·kg-1 cellulase, 35 087.7 U·kg-1 xylanase, 1 917.1 U·kg-1 β-mannanase, 305.0 U·kg-1 α-galactosidase, 806.7 U·kg-1 β-glucanase and 133.7 U·kg-1 pectinase for wheat-soybean diet. 3） The IVDMD of corn-soybean-DDGS diet and wheat-soybean diet with the optimal NSP enzymes were increased by 3.89% and 3.48%, respectively. The optimal NSP enzyme components effectively improve the IVDMD of corn-soybean-DDGS diet and wheat-soybean diet. The in vitro digestion method based on physiological parameter of growing pigs can be used as a convenient and rapid method for screening NSP enzyme components of a swine diet.