绵羊日粮的阳离子交换量与其纤维物质在胃肠道中的消化动力学的关系研究

采用12头安装有瘤胃和十二指肠瘘管的绵羊作为试验动物，随机分成4组，研究以稻秆(RS)、小麦秸(WS)、玉米秸(MS)和花生藤(PV)4种不同的阳离子交换量(CEC值)为主的绵羊日粮对纤维物质消化动力学、瘤胃降解率和瘤胃内环境参数的影响。结果表明：不同日粮的CEC值不同，具有较高CEC值的日粮(如玉米秸和花生藤)，营养价值也较高，其营养物质在十二指肠和直肠的流通量要比CEC值低的日粮(稻秆和麦秸)小，但具有较高的消化率，其粗纤维物质具有较多的可消化营养物质(a b)和较高的表面可发酵指数(SAFI)以及较高的瘤胃降解率。同时，随着日粮CEC值升高，各种营养物质在十二指肠和直肠中的流通量呈下降的趋势，各种营养物质在绵羊消化道中各部位的消化率呈上升的趋势，而且各营养物质的瘤胃降解率也有逐步升高的趋势。

Study on the Relationship between Dietary Cation Exchange Capacity (CEC) and Digestion Kinetics of Fiber in the Forestomach-intestines Tract of Sheep

Twelve sheep with permanent rumen and duodenum cannula were chosen as experiment animals and were divided into four groups in a randomized design to study the relationship of the CEC values in the roughage feedstuff diet including rice straw, wheat straw, maize stover and peanut vine and the digestion kinetics, the fermentation and degradation of fibre in the forestomach-intestines tract and the parameters in the rumen inner-environment in sheep. The results showed that the CEC values in different diet were different and the diets with higher CEC value (maize stover and peanut vine) had also higher nutritive values. The nutrient flow of diets with higher CEC values in the duodenum and rectum was lower than those with the lower CEC value (rice straw and wheat straw), and the fibrous materials of diet with higher CEC value had higher digestibility. The available nutrient components (a b), surface area fermentational index (SAFI) and ruminal degradation rate for the diet with higher CEC value were also higher than the diet with lower CEC value. At the same time, with increasing the CEC value, the nutrient flow to the duodenum and rectum tract decreased, the digestion rate in whole tract and ruminal degradation rate increased.