Effects Of Xinyang Maojian Broken Tea Supplementation In High Fat Diet On Muscle Nutrient And Lipid Metabolism Of Yellow River Carp（Cyprinus Carpio ）

Under the intensive cultivation mode,lipid metabolic diseases,muscle quality decline and low immunity are widespread in the Yellow River carp（Cyprinus carpio）.Which has affected the healthy development of the carp aquaculture industry,it is urgent to reduce excessive lipid deposition in fish and improve the quality of aquatic products.Studies have shown that tea is rich in active material such as tea polyphenols,tea polysaccharide,which could promote the transformation absorption of lipid,enhance immunity,and improve the quality of aquatic products etc.However,in the process of tea transportation,production and packaging,large number of break tea was produced,which not only pollutes the environment but also wastes resources.The nutrients and functional components in the broken tea are the same as those in the whole tea.If the broken tea can be reasonably added into the feed of Cyprinus carpio,it will play a double role in alleviating excessive fat accumulation and protecting the environment.Thus,in this study,using Cyprinus carpio as the research object,adding Xinyang Maojian Broken Tea(BT_Maojian)in carp feed,setting the control group,high-fat group（HF）,HF+1%BT,HF+2%BT and HF+3%BT group,respectively,an 8-week culture experiment was conducted to analyze the effects of BT_Maojian on the growth performance,conventional nutrients,antioxidant capacity,fatty acid composition,lipid deposition in tissues and expression of key genes in lipid metabolism of Cyprinus carpio.This study clarifies the regulatory effects of BT_Maojian on muscle quality and lipid metabolism of Cyprinus carpio.The main results were as follows:1、Effects of BT_Maojian on the growth,antioxidant capacity and intestinal structure of Cyprinus carpio.Compared with the control group and HF group,the addition of 2%and 3%BT_Maojian significantly increase the rate of weight gain and specific growth factor of Cyprinus carpio（P<0.05）.The contents of T-AOC and T-SOD in serum and liver of Yellow River carp in HF group were significantly decreased,and the addition of BT_Maojian could increase the above two oxidation parameters to the level of control group in different degrees;unlike the decrease of MDA in serum of the HF group,the MDA in liver of the HF group was increased significantly,while the activity of MDA enzyme was decreased to different degrees by BT_Maojian in the HF group carp liver,indicating that BT_Maojian can improve the antioxidant capacity of the Yellow River carp.Intestinal morphology observation results show that in HF group,the villi in the middle intestine were short and wide,and the brush edge was not obvious;But in HF+3%BT_Maojian group,the intestinal villi of Yellow River carp were longer and extended into the intestinal cavity uniformly.It was suggested that BT_Maojian could alleviate the intestinal damage of Yellow River carp caused by high fat feeding.2、Effects of BT_Maojian on conventional nutrients,muscle amino acid composition and the muscles,liver,intestinal fatty acid composition of Cyprinus carpio.The content of whole fish protein in HF+2%BT and HF+3%BT group is significantly higher than those in the other three groups（P<0.05）;Different proportions of broken tea added is significantly increase the muscle in the content of essential amino acids and half essential amino acids（P<0.05）;in addition,BT_Maojian can increase the content of aspartic acid significantly（P<0.05）.Considering the content of FAs,we found that in BT_Maojian addition groups,the contents of C18:2n6,C18:3n3 and∑PUFA/∑SA in muscle were increased to different degrees,which suggested that BT_Maojian could improve the quality of Yellow River carp.Similarly,in HF+2%BT group,the contents of C18:3n3,∑PUFA/∑SA and∑ω-6/∑ω-3 in liver were significantly higher than those in other groups（P<0.05）.Besides,the content of C18:3n3 in intestinal tract of each BT_Maojian supplemental group was also increased significantly（P<0.05）.In conclusion,BT_Maojian can promote the synthesis of PUFAs in different tissues of carp.3、Effects of BT_Maojian on lipid deposition and lipid metabolism related enzyme activity of Cyprinus carpioIn HF and HF+1%BT group,the fat accumulation was increased in liver of Cyprinus carpio,and the lipid droplets in liver cell were increased significantly;With the addition of BT_Maojian,the fat content of liver decreased,and the morphology of liver cells tended to be normal.Physiological and biochemical index determination results showed that the content of HDL-C in serum of HF+2%BT group carp is significantly higher than the rest of the four groups（P<0.05）;the content of LDL-C and AST in serum and liver of HF group carp were significantly higher than control group（P<0.05）,meanwhile,the contents of these two indexes in serum and liver of HF+1%HF+1%BT group were significantly lower than those of high fat group（P<0.05）.Thus,we speculated that BT_Maojian can improve the characterization of lipid metabolism disorders caused by high fat food.4、Effects of BT_Maojian on the expression of key lipid metabolism genes in liver,muscle and abdominal fat of Cyprinus carpio.The expression levels of lipid synthesis key genes（FASN,PPARγ,SREBP-1）in liver,the key tissues of fat metabolism,showed a trend of increasing firstly（HF group）and then decreasing(BT_Maojian group);meanwhile,the expression of key lipid decomposition genes（HSL and PPARα）in HF+3%BT group was increased significantly,while the expression of fat transporter gene（CD36）was decreased in the higher fat group significantly.These genes may be the main reason to explain why BT_Maojian can alleviates the excessive accumulation of hepatic fat in liver of high fat group carp.Similarly,most of key lipid metabolic genes in muscle and adipose tissue,which are the key tissues for fat storage,were increased at first and then decreased,suggesting that BT_Maojian regulates lipid accumulation and mobilization in muscle and abdominal cavity of carp.In conclusion,the addition of BT_Maojian can improve the growth performance and muscle quality of Cyprinus carpio,improve the adverse symptoms such as low antioxidant capacity,intestinal damage and excessive fat accumulation in liver.Therefore,BT_Maojian can be used as a green feed additive applied in the feed production of Cyprinus carpio.