Studies On The Optimal Vitamin A,D₃,E Requirements By Juvenile Sea Cucumber（Apostichopus Japonicus Selenka）

Part 1: An 8-week feeding experiment was conducted to evaluate the effects of vitamin A on growth performance,digestion and physiological and biochemical index of juvenile sea cucumber Apostichopus japonicus Selenka.Six isonitrogen and isoenergetic diets were formulated by adding 0(A1),2000(A2),4000(A3),6000(A4),8000(A5),12000(A6)IU/kg into basal diet(measured value: 3250,5187,7054,8970,12975,16400 IU/kg).Juvenile sea cucumber with initial body weigh(15.48±0.01)g were fed.Results showed as follows: 1)There was no significant influence on survival rate(SR)of sea cucumber,both the weight gain rate(WGR)and specific growth rate(SGR)were siginficantly improved,and the A1 group significantly lower than that of other groups(P<0.05),and the A4 group reached the top.There were no significant difference between A6 group and other groups of ratio of intestine weight to body weight(IWR)(P>0.05),but the A1 group was significant lower than other four groups(P<0.05).The deposition amount of VA in the body wall increased.2)There was no significant effects of VA on the contents of moisture,crude protein of the body wall(P>0.05).With the increasing of VA,the content of crude lipid of body wall increased,and crude ash contents of body wall increased and thereafter declined.The contents of zinc of body wall showed the same trend as the crude ash,both the contents of iron and VA were ascending.3)VA had no effect on the activity of intestinal protease(P>0.05).With the increasing of VA,the activity of lipase increased,and the A1 group was significantly lower than other groups.The activity of amylase was increased first and then decreased,and the A4 group was the highest.4)The activities of alkaline phosphatase(AKP),glutamic oxalacetic transminase(GOT),total superoxide dismutase(T-SOD)activity and malondialdehyde(MDA)content were significantly effected by VA.With the increasing of VA,both the activity of AKP and T-SOD were first up and then down,and the activity of AKP of the A1 group was significantly lower than othergroups(P<0.05).The activity of T-SOD in A2-A5 group were significantly higher than that in A1 group(P<0.05),and there was no significant difference between A1 and A6 group.The activity of GOT was decreased first and then uplifted,and reached the lowest in the A4 group.The contents of MDA were decreased.VA had no effect on the activity of glutamic-pyruvic transaminase(GPT)(P>0.05)and catalase(CAT).In conclusion,analysis by a linear regression equations of WGR indicated that the optimum demand of VA for sea cucumber(initial body weight 15.48g)was 11000IU/kg.Part 2: A feeding trial was conducted to evaluate the effects of vitamin D3 on growth performance,body composition,digestion,antioxidant capacity of juvenile sea cucumber Apostichopus japonicus Selenka.Six isonitrogen and isoenergetic diets were formulated by adding 0(D1),250(D2),500(D3),1000(D4),2000(D5),3000(D6)IU/kg VD3 into basal diet(measured value: 95,334,570,1076,2063,3081 IU/kg).Juvenile sea cucumber with initial body weight(15.43±0.14)g were fed for 8 weeks.Results showed that : 1)VD3 had no effects on survival rate(SR)(P>0.05)of sea cucumber,both weight gain rate(WGR)and specific growth rate(SGR)were siginficantly improved,and D1 group significantly lower than that of other groups(P<0.05),ratio of intestine weight(IWR)to body weight of D3,D4 and D5 groups were significantly higher than the other three groups(P<0.05),but there were no differences among them(P>0.05).2)With the increasing of VD3,moisture,crude protein and crude lipid contents of body wall were not affected significantly(P>0.05),but crude ash contents of body wall increased and thereafter declined and reached the maximum at D5 group,the contents of hydroxyproline of body wall decreased first and then increased,and reached the lowest in the D4 group(P<0.05).The deposition amount of VD3 in the body wall increased first and then decreased,and the D4 group reached the highest value,significantly higher than other groups.VD3 significantly increased the contents of calcium of body wall(P<0.05),also the contents of phosphorus increased at first and kept stable then,and the contents of phosphorus of D4,D5 and D6 groups were significantly higher than that of D1 group(P<0.05),but there were no differences among them(P>0.05).The contents of magnesium of body wall were all on the rose by dietary VD3,and all experimental groups were significant higher than that of D1 group(P<0.05).The contents of iron increased first and then decreased,and the group of D5 and D6 was significantly lower than that of the other groups(P<0.05),and the contents of manganese were decreased,but the difference between each group was no significant(P>0.05).3)VD3 had no significant effects on intestinal protease,amylase and lipase content(P>0.05).4)With the increasing of dietary VD3 levels,both the activities of alkaline phosphatase(AKP)and total superoxide dismutase(T-SOD)in intestine of experimental groups first rose and then declined,while the contents of malondialdehyde(MDA0 were decreased.The total antioxidative capacity(T-AOC)and the activitie of catalase(CAT)in intestine of all groups were not significantly affected(P>0.05)by VD3.In conclusion,analysis by a linear regression equations of WGR indicated that the optimum demand of VD3 for sea cucumber(initial body weight 15.43g)was 1587.5IU/kg.Part 3: The aim of the experiment was to determine the effects of vitamin E on growth performance,body composition,digestion,physiological and biochemical index of juvenile sea cucumber Apostichopus japonicus Selenka.Six isonitrogen and isoenergetic diets were formulated by adding 0(E1),80(E2),160(E3),240(E4),320(E5),400(E6)mg/kg into basal diet(measured value: 0、73、152、228、295、364mg/kg).Juvenile sea cucumber with initial body weight(15.43±0.14)g were fed for 8weeks.Results showed that: 1)VE had no effect on the survival rate(SR)of the sea cucumber,both the weight gain rate(WGR)and specific gain rate(SGR)were first rose then descended,and the E4 group reached the highest value.2)VE had no significant effects on contents of moisture,crude protein and crude ash(P>0.05).With the increasing of VE,the contents of crude lipid in the body wall was rose and then fall,and reached the top in the E5 group.The contents of selenium of body wall showed the same trend as the crude lipid.The accumulation of VE in the body wall of sea cucumber showed an upward trend,and the E1 group was significantly lower than that in other gruops(P<0.05),but there was no significant differences between them(P>0.05).3)The activity of intestinal trypsin was not effected by VE.With the increasing of VE,both the activity of lipase and amylase were first rise then descend.4)With the increasing dietary VE,the activity of intestinal AKP showed an upward trend,while the GOT activity of intestinal decreased first and then increased,and reached the lowest in the E4 group.The contents of MDA decreased with the increasing of the VE,and the E1 group was significantly higher than those in other groups.The trend of T-SOD activitywas opposite to the GOT activity.VE had no effect on the activity of intestinal CAT activity.In conclusion,analysis by a linear regression equations of WGR indicated that the optimum demand of VE for sea cucumber(initial body weight 15.41g)was 253.33mg/kg.