体外法估测日粮和饲料原料外源代谢葡萄糖值

Estimation of exogenous metabolic glucose value in diets and feed raw materials in vitro

试验旨在建立体外测定日粮和常用饲料原料中外源代谢葡萄糖(MG)含量的方法。试验采用单因子设计,以小肠消化时间为处理因素,分为1、2、4、6h和8h共5个处理。通过“胃蛋白酶-胰蛋白酶两段法”以四种不同日粮为底物进行体外模拟消化。将体外法测得的日粮淀粉降解率与体内法测得的日粮淀粉消化率进行相关性对照,确定两者相关系数最高的时间点,且将此设定为体外模拟消化的最佳时间。用此模拟消化时长,测定6种猪料原料外源MG水平。结果显示,体外法测定淀粉消化率,最佳的消化时长为6h,此时与体内法测定的淀粉消化率建立的回归方程为:y=0.1374x+84.834(R^2=0.8711)。最终得到体外法估测日粮外源MG的公式:外源MG=小肠淀粉量×(0.14×体外法测的小肠淀粉消化率+84.83)/0.9,并根据此方法测定出了几种常用饲料原料外源MG。

In order to establish the method for determining exogenous metabolic glucose level of feed and common feedstuff by simulating small intestinal digestion system in vitro.Digestion time was set as a single factor in this experiment,five treatments were divided into 1,2,4,6 h and 8 h,and four diets were managed to simulate digestion in vitro by "pepsin- trypsin two- stage method".Correlation analysis was conducted on the digestibility of starch in vivo and the degradation rate of dietary starch measured by in vitro.Setting the time period with the best correlation as a simulating digestion time in vitro.Therefore,the contents of exogenous metabolized glucose in six kinds of feedstuff were determined.The results showed that the optimal digestion time for simulating small intestinal digestion in vitro was 6 h,and the regression equation was y=0.137 4x+84.834(R^2=0.871 1).Thus,the estimated formula for the determination of exogenous glucose metabolism in vitro was IDSG = small intestine starch×(0.14×intestinal starch digestibility measured by in vitro method +84.83)/0.9,and several of common feedstuff were determined according to this method.