Study On Nutrition Physiology Of Copper, Selenium And Cobalt In Litopenaeus Vannamei

In the present study,feeding trials were conducted to determine the effect of copper,selenium and cobalt with different sources and supplement on growth performance,serum biochemical and non-specific immune response for Litopenaeus vannamei juvenile.The brief summarys are as follows:1.An 8-week feeding trial was conducted to study the effects of copper sources and supplement level on growth,non-specific immune enzyme activities and amino acid contents in the muscle of Litopenaeus vannamei.Two-factors is designed,and treatments consisted of 0,8,16,32 or 64 mg supplemental Cu/kg from hydroxyl methionine copper(HMC),tribasic copper chloride(TBCC)or copper sulfate(SC).A total of 1560 shrimp with an initial body weight of(0.330±0.001)g were randomly distributed into thirty-nine0.38 m~3 fiberglass tanks with 40 shrimp per tank and 3 tanks per diet.The feeding experiment lasted for 8 weeks.The results showed that weight gain rate(WGR),specific growth rate(SGR)and survive rate(SR)were not significantly affected by three sources of copper(P>0.05).However,WGR,SGR,SR were significantly affected by level of copper and 8 to 64 mg/kg groups higher than control(P<0.05).Different dietary sources and level of copper had significant influences on total protein(TP),glucose(GLU),triglycerides(TG)content(P<0.05),copper sources and level had interaction in TP(P<0.05),and the highest TP was found in 32mg/kg of HMC.Total superoxide dismutase(T-SOD),copper-zinc superoxidedismutase(Cu-ZnSOD)inhepanoreatic,phenoloxidase(PO)and ceruloplasmin(CP)in serum were significantly effected by different sources of copper(P<0.05).The highest T-SOD,CP,Cu-ZnSOD and PO activities were found in 64,16,32,32 mg/kg of HMC respectively.Glycine,alanine,aspartic acid,glutamic acid,arginine contents in muscles were significantly effected by copper sources(P<0.05).There were a significant interaction between copper sources and copper concentration in the hepanoreatic selenium concentrations.Analysis by polynomial regression of WGR of shrimp indicated that the optimum dietary copper requirement as HMC,TBCC or SC was17.52 mg/kg,20.32 mg/kg and 20.29 mg/kg for Litopenaeus vannamei.Using broken line equation and a slope ratio technique,relative bioavailability values of HMC and TBCC with SC as the standard,was respectively 115.15%and 71.88%for serum ceruloplasmin.By comparing,the HMC had the highest relative bioavailability,followed by SC,and the lowest is TBCC.2.An 8-week feeding trial was conducted to study the effects of selenium sources and supplement level on growth,non-specific immune enzyme activities and interaction between selenium and vitamin E of Litopenaeus vannamei.Twenty-seven purified diet containing graded levels of dietary selenium(0,0.1,0.3,0.6,1.0 mg/kg)from sodium selenite(Se-S),selenomethionine(Se-M)or selenoyeasy(Se-Y)and vitamin E(0,100,200 mg/kg).A total of 3240 shrimp with an initial body weight of(0.576±0.001)g were randomly distributed into eighty-one 0.38 m~3fiberglass tanks with 40 shrimp per tank and3 tanks per diet.The results showed that there were a significant interaction between selenium sources and selenium concentration in the WGR and SGR,but had no significant interaction on SR of white shrimp(P>0.05).The serum glutathione peroxidase(GSH-Px),serum glutathione reductase(GR),serum PO and liver GSH-Px of shrimp had significant interaction between selenium sources and selenium concentration(P>0.05).Significant interaction between selenium sources and selenium level were found in liver and muscle selenium concentration of shrimp(P>0.05).Dietary vitamin E level and selenium both significantly affected WGR and SGR(P<0.05),however,SR were not significantly affected(P>0.05),when Se-S as selenium.Shrimp fed diets with the Se-M and vitamin E showed significantly affected on WGRand SGR(P<0.05),and SR were not significantly affected(P>0.05).Significant interaction between dietary vitamin E and selenium from three selemiun sources were found in serum GSH-Px,serum GR,serum PO,liver GSH-Px and hepanoreatic selenium concentrations of shrimp(P<0.05),but were not significant interaction in muscle selenium concentrations(P>0.05).Analyzed by second-order and broken-line model with WGR,the dietary Se requirement of Litopenaeus vannamei was estimated to be 1.00 mg/kg,0.96 mg/kg,0.64 mg/kg from Se-S,Se-M or Se-Y respectively,by comparing,the Se-Y had the highest relative bioavailability,followed by Se-M,and the lowest was TBCC;a broken line equation for serum GSH-Px showed that the optimum dietary selenium requirement as Se-S,Se-M or Se-Y was determined to be 0.87 mg/kg,0.78 mg/kg and 0.64 mg/kg for Litopenaeus vannamei.There is a significant interaction between selenium and vitamin E in the nutrition of Litopenaeus vannamei.3.An 8-week feeding trial was conducted to study the effects of cobalt sources and supplement level on growth,non-specific immune enzyme activities and cobalt contents in tissues of Litopenaeus vannamei.An eleven purified diet containing graded levels of dietary cobalt(0,5,10,20,40,80 mg/kg)from cobalt chloride(Co-C)and Cobalt-Methionine(Co-M).A total of 1320 shrimp with an initial body weight of(0.494±0.001)g were randomly distributed into thirty-three 0.38 m~3 fiberglass tanks with40 shrimp per tank and 3 tanks per diet.The results showed that different dietary sources and level of cobalt had significant influences on WGR and SGR.There were significant differences in the WGR and SGR cobalt levels(P<0.05),but there were no significant differences in SR.Shrimp fed diets supplemented with 10 mg Co/kg from cobalt methionine diets had the highest WGR,SGR.Different dietary sources and level of cobalt had significant influences on TG,TP and cholesterol(CHOL)content(P<0.05),but had no significant effect on GLUC of white shrimp(P>0.05).Cobalt sources and level had interaction in alanine transaminase(ALT),aspartate taansaminase(AST),lactate dehydrogenase(LDH)(P<0.05).Hepanoreatic cobalt concentration were significantly effected by cobalt sources and levels(P<0.05).The broken line equations for weight gain showed that the optimum dietary cobalt as Co-C and Co-M requirements were determined to be 47.11 mg/kg and 7.06 mg/kg for Litopenaeus vannamei,respectively,Co-M had higher relative bioavailability than Co-C.