The Research Of Requirement Of Dietary Lipid And N-3HUFA For Sea Cucumber (Apostichopus Japonicus) Juveniles

Text1was conducted to determine the optimum dietary lipid level of sea cucumberApostichopus japonicus juvenile focusing on growth performance, digestive enzyme andproximate compositions of body wall. Diets with six crude lipid levels (0.19,1.38,2.91,4.36,5.96and7.16%) were fed to sea cucumber juveniles (0.65±0.004g) once a day for60days. Thebody weight gain (BWG), specific growth rate (SGR), feed intake (FI) and PER generallydecreased with increasing dietary lipid levels. The sea cucumbers fed diets containing0.19%crude lipid shown the maximum BWG than those of other treatments. The sea cucumbers feddiets containing1.38%crude lipid shown the minimum protease than those of other treatments.The sea cucumbers fed diets containing7.16%crude lipid shown significantly (P <0.05) higherlipase level than those of sea cucumbers fed diets containing0.19and1.38%crude lipid. The seacucumbers fed diets containing crude lipid exceed7.16%shown significantly (P <0.05) highereicosapentaenoic acid (EPA) level of body wall than those of sea cucumbers fed diets containing0.19%crude lipid. The content of docosahexaenoic acid (DHA) of sea cucumber body wallincreased at first and decreased subsequently with increasing dietary crude lipid. The content ofn-3highly unsaturated fatty acids (HUFAs) of sea cucumber body wall followed the same pattern,reached a maximum value at a crude lipid level of1.38%., but not different (P>0.05) from thesea cucumbers fed diets containing crude lipid exceed2.91%. In conclusion, it can be indicatedthat the optimum dietary lipid are0.19-1.38%for sea cucumber juveniles.Text2was conducted to determine the optimum level of dietary n-3HUFAs for sea cucumberjuveniles focusing on growth performance and body wall composition. Diets with five n-3HUFAlevels (0.15,0.22,0.33,0.38and0.46%) were fed to sea cucumber juveniles (1.97±0.01g) oncea day for60days. High survival was shown (>97%) and not affected by dietary n-3HUFA level.The sea cucumbers fed diets containing0.22%n-3HUFA showed significantly (P <0.05) higherfeed efficiency and protein efficiency ratio than those of the sea cucumbers fed diets containing0.15%n-3HUFA. The body weight gain followed the same pattern, but no significantlydifference (P>0.05) was observed among all treatments. No significantly differences (P>0.05)were observed in moisture, crude protein, crude lipid, ash, and carbohydrate content of the bodywall among all treatments. The16:0and18:1were the most abundant saturated and monoenoicfatty acids, respectively. The content of EPA and DHA of sea cucumber body walls generallyincreased with increasing dietary n-3HUFA level. The sea cucumbers fed diets containing0.46%n-3HUFA showed higher n-3HUFA content, but no significantly difference (P>0.05) wasobserved among all treatments. According to the growth performance and fatty acidcompositions of sea cucumber body walls, it can be indicated that the optimum dietary n-3 HUFAs are0.22-0.38%for sea cucumber juveniles.