Effects of Dietary Skimmed Krill Meal on the Growth, Non-Specific Immunity and Serum Physiological Metabolism Indicesof Juvenile Spotted Halibut (Verasper variegatus)

Abstract:

An 8-week feeding trial was conducted to evaluate the effects of dietary skimmed krill meal (SKM) on the growth performance, serum biochemical parameters and non-specific immunity of juvenile spotted halibut (Verasper variegatus). The basal diet was formulated with fishmeal and SKM as the protein resource, and fish oil as the lipid resource. The control diet (R0) did not contain SKM, and 6 other diets were supplemented with SKM at 6.33% (R10, 10% replacement of the fishmeal protein. The same were as follows, 12.66%(R20), 18.99%(R30), 25.32%(R40), 31.66%(R50) and 63.31%(R100). These diets were then fed to seven groups of juvenile spotted halibut with initial weight of (60.11±0.13) g. Results showed that the specific growth rate, survival rate and feed efficiency of R10–R50 groups were not significantly different from those of R0 (P>0.05), but it displayed a decreasing trend from R30. The hepatosomatic index and viscerosomatic index of R10–R30 groups were not significantly different from those of R0 (P>0.05). The serum acid phosphatase in R10 and R20 was significantly higher than that in R0 (P<0.05). The serum acid phosphatase of R30 was not different from that of R0 (P>0.05). The serum alkaline phosphatase in R30–R100 groups was significantly higher than that in R0 (P<0.05). The serum SOD of R10 was not different from that of R0 (P>0.05). The liver acid phosphatase in R10 was significantly higher than that in R0 (P<0.05). The liver alkaline phosphatase of R30 and R40 was not significantly different from that of R0 (P>0.05). The liver SOD of R10–R40 groups was not significantly different from that of R0 (P>0.05). The serum total protein of R10–R50 groups was significantly higher than that of R0 (P<0.05). There was no difference in the viscerosomatic index and glutamate dehydrogenase among groups (P>0.05). The results above showed that 10%–30% of SKM replacement might have the same effects on the growth performance, feed efficiency ratio and non-specific immunity of juvenile spotted halibut.