Abstract:

To investigate the influence of dried earthworm powder (DEP) on growth performance, activity of digestive enzymes and immunity of juvenile Sea Cucumber Apostichopus Japonicus (SCAJ), five kinds of feeds at the same protein level (18.6%) were prepared by using DEP to replace fish meal at four levels of 20% (20DEP), 40% (40DEP), 60% (60DEP) and 80% (80DEP), with 100% fish meal as a control group. A 30-day feeding trial was conducted to evaluate the feeding effect of juvenile SCAJ fed with the five formulated feeds. The results showed that SGR (specific growth rate) and RS (survival rate) of juvenile SCAJ in the control group were significantly lower than those of juvenile SCAJ in the other groups (P<0.05); Activity of protease, amylase, lipase, cellulase and ACP, AKP, T-SOD of juvenile SCAJ fed with 20DEP and 40DEP was all extremely higher than those of juvenile SCAJ in control group (P<0.01); Along with the percents of DEP substituting for fish meal increasing gradually, all of the evaluation indexes fell back, and in contrast with the control group, 60 DEP substitution for fish meal suppressed greatly T-SOD activity of juvenile SCAJ (P<0.05); what's more, 80 DEP substitution for fish mea impaired observably activity of protease and immunoenzyme of juvenile SCAJ (P<0.05). The results indicated that to juvenile SCAJ, 20% DEP substitution for fish mea can promote growth, improve activity of digestive enzymes and enhance disease resistance.