大菱鲆的赖氨酸最适需求量研究OA北大核心CSTPCD

In order to optimize the lysine requirement of turbot(Scophthalmus maximus L.)and evaluate the effects of dietary lysine level on plasma biochemical indexes,digestive enzyme activity antioxidant and immune function of turbot,five isonitrogen(about 50％crude protein)and isolipid(about 12.5％crude fat)diets were designed in this study,of which the lysine contents were 1.69％,2.49％,3.32％,4.11％and 4.90％respectively,and fed for ten weeks.The results showed that when the dietary lysine content increased to 3.32％,the growth performance gradually improved,and then stabilized.Low dietary lysine content will adversely affect the feed utilization of turbot.With the increase of dietary lysine content from 1.69％to 4.90％,whole body lipid decreased and the protein increased.The liver body index(HSI)of fish also decreased with the increase of dietary lysine content.In terms of intestinal digestive enzyme activity,lipase and trypsin increased first and then decreased with the increase of dietary lysine content,reaching the highest level at 3.32％lysine.The addition of dietary lysine did not affect blood glucose content while plasma triglyceride(TG)content and total cholesterol(T-CHO)content increased significantly in 1.69％group and 2.49％group.In addition,the appropriate content of lysine can improve the antioxidant capacity of turbot liver and alleviate the inflammatory response by regulating nonspecific immunity.In this study,we found that when the dietary lysine content is about 3.19％of feed dry weight(6.39％of dietary protein),it can play its effective role to the greatest extent.