过瘤胃保护蛋氨酸稳定性及其评定方法的研究

Study on Stability and Assessment Methods of Rumen-protected Methionine

本研究应用双外流连续培养系统和瘤胃尼龙袋法检验动物油包被蛋氨酸在瘤胃中的稳定性。根据动物油添加比例不同(分别添加20%、30%和40%),保护性蛋氨酸分为过瘤胃保护蛋氨酸I(RPMet-I)、过瘤胃保护蛋氨酸II(RPMet-II)和过瘤胃保护蛋氨酸III(RPMet-III)。试验结果表明:与未包被蛋氨酸相比,动物油包被蛋氨酸在瘤胃中的释放率显著降低(P<0.05);动物油添加比例不同对于过瘤胃保护蛋氨酸的稳定性影响显著(P<0.05)。不同形式保护性蛋氨酸在双外流连续培养系统中的降解趋势与在瘤胃中的降解趋势相似,且应用双外流连续培养系统测定各个时间点保护性蛋氨酸的释放率简单、稳定,与瘤胃尼龙袋法相比各个时间点的释放率均存在强相关回归关系(n=5,P<0.01),因此该系统适宜于评定保护性氨基酸的稳定性。

Rumen-protected methionine （RPMet） was made with different proportion of grease and DL-Met, and its stability was studied by dual-flow continuous culture system and rumen nylon bag method. The results showed that the release rates of RPMet were significantly lower than that of DL-Met （P〈0.05） ; the proportions of the appended grease have significant effect （P〈0.05） on the stability of RPMet. Different forms of RPMet have similar degradable trend in the dual-flow continuous culture system and in the rumen. It was simple and stable to measure the release rates of RPMet with continuous culture system. A regression equation for the release rates of incubation times of RPMet between using continuous culture system and rumen nylon bag method was established. The dual-flow continuous culture system is a feasible method to assess the stability of RPAA. [Chinese Journal of Animal Nutrition, 2006,18 （3） ： 203- 207 ]