鱼类对饲料可消化糖的利用和代谢特征

糖类是鱼类三大营养物质之一，可消化糖作为一种性价比较高的能量物质，其合理利用对饲料成本的降低和饲料物理性状的维持具有重要意义，但鱼类对糖的利用有限，投喂含有一定比例可消化糖的膨化商业饲料易引起肝脏疾病的发生。文章总结了部分已发表关于鱼类糖耐受和生长试验结果的报道，发现不同鱼类对葡萄糖的代谢模式存在一定的差异，一些鱼类倾向于将过量葡萄糖以糖原的形式储存在肝脏中，而有些鱼类则既能合成糖原也能合成脂肪。糖耐量试验是了解鱼类利用可消化糖类的重要研究手段，但目前还没有统一的标准，导致研究结果的参考意义不强。作者建议将来在统一方法标准的基础上，重点研究不同鱼类的葡萄糖代谢特征以及调控方法。

Utilization and metabolism of dietary digestible carbohydrates in fish

Carbohydrate is one of three major nutrients of fish. A growing number of studies have focused on the effects of dietary digestible carbohydrates on different fish species. Carbohydrates are the most abundant energy-yielding nutrients and economically indispensable in commercial fish feed formulation. The rational utilization of digestible carbohydrate is of great significance to the reduction of feed cost and the maintenance of feed physical properties. On the other hand, the rapid development of special aquaculture fish in recent years is limited in the use of sugar.Feeding commercial feed containing a certain proportion of digestible carbohydrate is often easy to cause the occurrence of liver disease. The pathways of digestion, absorption and metabolism of digestible carbohydrate in fish are basically similar to those in mammals, but there may be great differences in metabolism and specific pathways. The previous results of glucose tolerance test and feeding trial indicated that different fish species had different ability in the metabolism of glucose. Excess glucose will be stored as glycogen by glycogenesis in some fish species, or be stored as both glycogen and lipid. At present, there is limited criterions for glucose tolerance test for fish species. In future, we need to understand more about the mechanism and regulation of glucose metabolism in fish species.