不同生长阶段和饲粮类型下猪空肠液在纯化过程中消化酶活性回收率的差异

Difference in Recoveries of Digestive Enzyme Activities during Purification Process for Jejunal Fluid of Pigs in Different Growth Phases and Diet Types

本试验旨在探讨不同来源的猪空肠液在消化酶纯化过程中活性回收率的差异,为体外仿生消化酶试剂的制备提供参考。试验采用2×2两因素完全随机设计,包括2个生长阶段[生长期(60~100日龄)和育肥期(101~140日龄)]和2种饲粮类型[玉米-豆粕型饲粮和玉米-玉米干酒糟及其可溶物(DDGS)-米糠粕型饲粮]。每个生长阶段采用2×2完全交叉设计,将8头安装有空肠T型瘘管的“大×长”二元杂交去势公猪随机分为2组,每组4头猪。在每个生长阶段各进行2期试验,交叉饲喂2种饲粮,形成每个处理8头猪(重复)。每期试验包括10d预试期和3 d空肠液收集期。待每期试验结束后将每头猪空肠液混合,然后采用无水乙醇沉淀法纯化空肠液中的消化酶,测定纯化过程中消化酶活性的损失和回收率。结果表明:1)不同来源空肠液经冰乙醇沉淀-复溶后获得的消化酶活性的回收率间无显著差异(P>0.05),且回收率均在70%以上;2)不同来源空肠液经冰乙醇沉淀-复溶-冻干后获得的消化酶活性的回收率也均无显著差异(P>0.05),且回收率均在60%以上;3)冰乙醇沉淀-复溶过程中消化酶活性的损失极显著高于冻干过程(P<0.01)。综合以上结果,不同生长阶段和饲粮类型下获得的猪空肠液在纯化过程中消化酶活性的回收率均无显著差异,且通过无水乙醇沉淀法可以获得满意的回收率。

This study was conducted to investigate the difference in the recovery of digestive enzyme activity of different jejunal fluid sources during purification process in pigs,to provide reference for the preparation of digestive enzyme in vitro. Two growth phases [growing period( 60 to 100 days of age) or fattening period( 101 to 140 days of age) ] and two diets [corn-soybean meal diet or corn-corn distillers dried grains with soluble( DDGS)-rice bran meal diet]were used in a 2×2 factorial arrangement in a completely randomized design.Eight growing crossbred barrows( Yorkshire×Landrace) surgically fitted with permanent T-cannula in the upper jejunum were randomly divided into 2 groups in a 2 × 2 change-over design with 4 pigs per group. Each phase contained 2 experimental periods and 2 diets were cross feeding with 8 pigs per treatment. Each experimental period lasted for 10 d acclimatization and 3 d jejunal fluid collection. The jejunal fluid was pooled of each pig after collection,and then purified by anhydrous ethanol precipitated. The loss and recovery of digestive enzyme activity were determined during the purification process. The results showed as follows: 1) there was no significant difference in the recovery of digestive enzyme activity among different sources of jejunal fluid after ice ethanol precipitated-redissolved process( P>0.05),and the recovery of enzyme activity was more than 70%. 2) No significant difference was observed in the recovery of digestive enzyme activity among different sources of jejunal fluid after ice ethanol precipitated-redissolved-freeze dried process( P>0.05),and the recovery of enzyme activity was more than 60%. 3) The loss rate of digestive enzyme activity in the precipitatedredissolved process was significantly higher than that in the freeze-dried process( P<0.01). In conclusion,no significant difference in the recovery of digestive enzyme activity in the purification process of jejunal fluid observed from pigs under different growing phases and diet types,and satisfactory recovery can be obtained using anhydrous ethanol precipitation.