木薯叶提取液制备及其对甲鱼生长的影响

本研究优化了木薯叶提取液制备的条件，并且检测该提取液对甲鱼生长性能、血液化学指标的影响。试验首先对提取木薯叶的溶剂提取法进行工艺优化，确定最优提取条件，包括：溶剂浓度、料液比、提取温度、提取时间4个因素。其次将提取液经处理后加入甲鱼饲料中，通过分析检测甲鱼存活率、生长性能、饲料转化性能、机体营养组成、血液生化及免疫能力指标，来确定其对甲鱼生长的影响。试验结果表明，木薯叶提取制备的最优工艺为：乙醇浓度50％，料液比（mL/g)40 ∶ 1，提取温度70 ℃，提取时间2 h；通过对甲鱼饲养的研究，表明饲料中添加木薯叶提取液能提高甲鱼的生长速度，降低饲料系数，并能降低甲鱼机体内血糖、胆固醇、甘油三酯水平，以及降低血清丙二醛含量，从而提高了甲鱼的糖代谢、脂肪代谢和免疫能力。因此，本研究不仅首次将木薯叶提取液作为添加剂加入甲鱼饲料，同时也为木薯叶提取液作为天然低毒的饲料添加剂提供了理论依据。

Liquid Extracting from Cassava Leaves and Its Effects on Growth of Soft-shell Turtles

The liquid extracting from cassava leaves and its effects on turtles’growth are optimized in the study. Firstly, the optimal process of extracting liquid from cassava leaves is determined. The extracting conditions include ethanol density, solid-to-liquid ratio, extracting temperature and extracting time. Secondly, the effects of the liquid of cassava leaves on the growth of soft-shelled turtle by determining the survival rate, growth performance, feed conversion ratio, trophic component of turtles, blood biochemical and immunity indicators are analyzed. The result shows that the optimal process conditions are percent of ethanol density（50%）, solid-to-liquid ratio（40:1), extracting temperature（70 ℃）, extracting time（2 h）. In conclusion, it indicates that the feed with the extracting liquid could improve the turtles’growth rate, decrease the feed coefficient, decrease the content of blood sugar, cholesterol and triglyceride of turtle and decrease MDA of turtle serum, so that the liquid could promote the glycometabolism, fat metabolism and immunity of turtle. Thus, this study not only firstly adds the liquid extracting from the cassava leaves into the turtles’feed, but also provides the theoretic reason for using the liquid as natural and low-toxic feed additive.