Application Of Raffinose And Schizochytrium Sp.in The Feed Of Juvenile Pacific White Shrimp,Litopenaeus Vannamei

The aim of this present paper is to study the effects of dietary raffinose and Schizochytrium sp.supplementation on the growth performance,non-specific immunity and the activity of digestive enzyme of juvenile Pacific White Shrimp,Litopenaeus vannamei.Major results and conclusions were presented as follows:1.An 8-week feeding trail was conducted to evaluate the effects of dietary raffinose supplementation on growth performance,non-specific immunity,digestive enzyme activity and stress resistance of juvenile Pacific White Shrimp,Litopenaeus vannamei.Six practical diets were formulated to contain graded levels(0 %,0.02 %,0.04 %,0.08 %,0.12 % and 0.2 %)of raffinose.Each diet was randomly assigned to quadruplicate groups,the shrimp were feed three times a day to apparent satiation.The results indicated that the weight gain and specific growth rate showed a rising trend with the increasing supplementation of raffinose,and when the raffinose supplementation was 0.2 %,the final weight and feed coefficient of the shrimp were significantly different from that of the control group.With the increased addition of raffinose,the level of serum triglycerides(TG)increased significantly,and the content of total cholesterol(T-CHO)decreased,total-antioxidant capacity(T-AOC)of hepatopancreas increased significantly,the malondialdehyde(MDA)content ofhepatopancreas showed the opposite tendency,acid phosphatase(ACP)and alkaline phosphatase(AKP)activity in hepatic pancreas increased significantly.And The relative gene expression of lysozyme(LZM)? superoxide dismutase(SOD)and glutathione peroxidase(GSH-PX)in hepatic pancreas increased significantly with the increasing levels of raffinose,but the relative gene expression of intestinal trypsin and chymotrypsin in five raffinose groups decreased when compared with the control group.In addition,with the increased addition of raffinose,the survival rate of shrimp was also increased after 24 h,48 h,72 h and 96 h of low dissolved oxygen stress.These results clearly indicated 0.2 % raffinose in feed for Litopenaeus vannamei could improve growth performance,non-specific immunity and the low dissolved oxygen stress tolerance of white shrimp.2.An 8-week feeding trail was conducted to evaluate the effects of dietary Schizochytrium sp.supplementation on growth performance,non-specific immunity and the activity of digestive enzyme of juvenile Pacific White Shrimp,Litopenaeus vannamei.Six practical diets were formulated: D1 is the control group and did not add algal powder,D2,D3 and D4 added 1.5 %,3.0 % and 4.5 % broken wall algal powder(Schizochytrium sp.),respectively,D5,D6 and D7 added 1.5 %,3.0 % and4.5 % unbroken wall algal powder(Schizochytrium sp.).Each diet was randomly assigned to triplicate groups,the shrimp were fed four times a day to apparent satiation.The results indicated the survival rate and weight gain rate of shrimp in D3 group were significantly higher than that of other groups,and feed coefficient showed opposite tendency.However,there was no significant difference in all growth indexes between three unbroken wall algal powder groups and the control group.In D3 group,serum triglycerides(TG)and total cholesterol(T-CHO)contents,the ratio of high-density lipoprotein to low-density lipoprotein(HDL/LDL),total-antioxidant capacity(T-AOC)of hepatopancreas,acid phosphatase(ACP)and alkaline phosphatase(AKP)activity in hepatic pancreas,the relative gene expression of superoxide dismutase(SOD),glutathione peroxidase(GSH-PX),pancreatic lipase in hepatic pancreas as well as intestinal trypsin and chymotrypsin were significantly higher than other groups,but the malondialdehyde(MDA)content of hepatopancreaswas significantly lower than other groups.These results clearly indicated 3.0 %broken wall algal powder(Schizochytrium sp.)in feed for Litopenaeus vannamei could significantly improve growth performance,non-specific immunity and intestinal digestive function.