反刍动物对淀粉的利用-内网入口.DOC

反刍动物对淀粉的利用( 汪水平，王文娟，左福元 （西南大学 荣昌校区动物科学系，重庆 402460） 摘 要：淀粉是谷物的主要能量组分。小麦干物质中淀粉含量为77%，玉米和高粱为72%，大麦和燕麦为57%和58%。谷物来源与加工方法对淀粉的消化位点及其消化率影响很大。小肠消化淀粉的能力受胰腺淀粉酶的限制。增加十二指肠蛋白质的数量，可促进胰腺分泌淀粉酶。小肠葡萄糖转运能力不受葡萄糖数量的限制。反刍动物对淀粉的利用与机体葡萄糖代谢密切相关。评价淀粉在小肠的利用效率，不能只考虑瘤胃淀粉发酵造成的潜在能量损失，而需要评定小肠葡萄糖吸收对代谢葡萄糖的贡献及大肠淀粉发酵的能量损失和对反刍动物健康的影响。从整体代谢能角度看，谷物淀粉在瘤胃发酵的利用效率最高。但是，只有保证瘤胃充分发酵并提供能发挥小肠葡萄糖主动转运能力的过瘤胃量，淀粉才得到最佳利用。 关键词：淀粉；反刍动物；消化；吸收；葡萄糖；代谢 Starch utilization by ruminants WANG Shui-ping, WANG Wen-juan, ZUO Fu-yuan (Department of Animal Science, Rongchang Campus of Southwest University, Chongqing 402460, China) Abstract: Starch is the major energy component of grains. Wheat contains 77% of DM as starch, corn and sorghum contain 72%, and barley and oats contain 57 to 58%. Grain sources and processing methods have a profound effect on starch digestibility and site of starch digestion. The capacity to digest starch in the intestine are apparently limited by the supply of pancreatic amylase. Amylase secretion may be enhanced by increasing duodenal entry of protein. Capacity for active transport of glucose across the gut wall does not seem to limit the amount of starch digested that is absorbed as glucose. High correlation exists between starch utilization and glucose metabolism by ruminants. It is not enough to consider separately the potential energy loss as a result of starch fermentation in the rumen for evaluating the efficiency of utilization about starch in the small intestine. Therefore, it is indispensable to evaluate the contribution of glucose absorbed from the small intestine to metabolizable glucose and the potential energy loss and healthy benefit as a result of starch fermentation in the large intestine. In terms of overall metabolizable energy yield, grain starch is best used when it is fermented in the rumen. However, the optimal utilization of starch can be realized when starch is adequately fermented in the rumen and the potential capacity of glucose transport across the gut wall are exerted. Key W