Effects Of Chinese Herbal Medicine On Growth,Enzyme Activity And Gene Expression Of Immune Factors Of Lates Calcarifer

Experiment Ⅰ: Explore the effect of adding different proportions of allicin on the digestive enzymes and liver immune enzymes of juvenile Lates calcarifer.In this study,80-days-old Lates calcarifer was used in the feeding trial.0% allicin was the control group,1%,5%,9% allicin were the testing group.The results showed that gastric amylase activity increased significantly in the 5% and 9% groups(P<0.05).Hepatic lipase activity increased significantly in the 1% and 9% groups(P<0.05).Pepsin activity in the 9% group significantly increased(P<0.05).The activity of hepatic catalase significantly increased in the 1% group(P<0.05).The activity of hepatic reduced glutathione significantly increased in the 1% and 9% groups(P<0.05).The content of liver malondialdehyde of the 9% group decreased significantly(P<0.05).This experiment showed that the addition of allicin in the feed could promote the digestive enzyme activity of the Lates calcarifer to certain extent,help the body to scavenge free radicals and improve the immunity of the fish.However,there were differences in the concentration of different digestive enzymes and immune enzymes.The appropriate addition range is between 5%-9%.Experiment Ⅱ: Explore the effect of different amounts of fresh ginger in feed on growth characteristics and immune enzyme activity of juvenile Lates calcarifer.Fresh ginger was smashed and used in this study.In this study,80-days-old Lates calcarifer was used in the feeding trial.0% ginger was the control group,1%,5%,9% ginger were the testing group.The results showed that special growth rate and weight gain rate were higher in each test group than in the control group,but was not significantly different(P>0.05).Condition factor decreased significantly in the 1% and 3% groups(P<0.05).The body length in terms of growth rate increased significantly in the 3%group(P<0.05).The survival rate of all test groups was significantly higher than that of the control group(P<0.05).Liver CAT activity increased significantly in the 1%group(P<0.05).Liver GSH increased significantly in the 5% group(P<0.05).Liver malondialdehyde content decreased significantly in the 3% and 5% groups(P<0.05).The changes of immune enzyme in serum were not obvious(P>0.05).This experiment showed that adding 1%-3% ginger in the feed can increase the feed intake,increase body length growth rate,improve the weight gain rate and special growth rate of Lates calcarifer,Adding ginger helps the body of Lates calcarifer to scavenge free radicals,improve antioxidant capacity,reduce liver damage,and has a better effect at 3%-5%.Experiment Ⅲ: Explore the effects of different contents of licorice powder in feed on growth characteristics,digestive enzymes,immune enzymes and immune genes of juvenile Lates calcarifer.In this study,80-days-old Lates calcarifer were fed with experimental diets.0% glycyrrhiza was the control group,1%,5%,9%glycyrrhiza were the testing groups.The results showed that survival rate increasedsignificantly in the 3% and 5% group(P<0.05).The body length in terms of growth rate of all test groups was significantly higher than that of the control group(P<0.05).Weight gain rate and special growth rate increased significantly in the 5% group(P<0.05).In foregut,AMS activity increased significantly in the 3% and 5% group(P<0.05).Liver AMS activity,foregut LPS activity,liver LPS activity,gastric LPS activity increased significantly in each test group(P<0.05).Foregut TRYP activity increased significantly in the 3% and 5% group(P<0.05).PP activity increased significantly in the 5% group(P<0.05).Liver T-AOC activity increased significantly in each test group(P<0.05).Liver CAT activity,Liver GSH-PX activity and Liver POD activity increased significantly in the 1% group(P<0.05).Liver MDA content decreased significantly in the 5% groups(P<0.05).Serum T-AOC activity and CAT activity increased significantly in each test group(P<0.05).Serum GSH-PX activity increased significantly in the 3% group(P<0.05).Serum LZM activity decreased significantly in the 1% and 5% groups(P<0.05).This experiment showed that adding3%-5% glycyrrhiza in the feed could promote the digestive enzyme activity,and improve fish body growth rate;It helps inhibit bacteria to improve the survival rate of Lates calcarifer,Added glycyrrhiza could improves antioxidant capacity and reduce liver damage,and has a better effect at 1%-3%.Compared with allicin,ginger,immune effect is stronger.Experiment Ⅳ: In order to analyze the immune mechanism of licorice on Lates calcarifer,explore the effect of licorice from the molecular level.The expressions of CRP,HSP90 and TNF up-regulated significantly in each test group(P<0.01).The expressions of IL10 and TGFβ1 up-regulated significantly in the 1% and 3% test group(P<0.01).The expressions of C3 up-regulated significantly in the 3% and 5%test group(P<0.01).The expressions of C4 up-regulated significantly in 1% the and5% test group(P<0.01).The expressions of m TOR,mlst8,e IF4 E and MX up-regulated significantly in the 5% test group(P<0.01).The expressions of HSP70 and INFγ1 down-regulated significantly in each test group(P<0.01).The expressions of IL8 down-regulated significantly in the 5% test group(P<0.01).This experiment showed that the addition of glycyrrhiza in the feed could affect the immune response system of Lates calcarifer at the molecular level,reduce pathogen invasion,up-regulation of m TOR,mlst8,MX,CRP,C3,C4,TNF and TGFβ1,down-regulation of HSP70、IL8 and IFNγ1.In conclusion,all these three additives,allicin,ginger and glycyrrhiza,had physiological and biochemical effects on Lates calcarifer.The addition of allicin at5%-9% had a certain promoting effect on the digestive ability and antioxidant ability of the Lates calcarifer.Ginger is a strong attractor,Ginger could promote growth rate when the added amount is between 1%-3%,And added 3%-5% could promote antioxidant capacity.Glycyrrhiza had a strong antioxidant capacity.Added 1%-3%could promote antioxidant capacity.The addition of 3%-5% could promote growth,and these three additives can be used at the same time.