Effects of the Fermented Soybean Meal as a Replacement of Algae Powder on the Growth Performance and Body Composition of Juvenile Sea Cucumber (Apostichopus japonicus)

Abstract:

In recent years, the fast development of sea cucumber (Apostichopus japonicus) farming overwhelmed the supply of algae powder as the feed. In this study, we investigated whether fermented soybean meal (FSBM) could be an effective replacement of algae powder. The algae powder and the mixture of fishmeal and algae powder (2∶15) were replaced with FSBM in this study. The growth performance and body composition were tested in A. japonicus with initial body weight of 17.7 g. In the 10-week feeding trial, nine isonitrogen experimental diets were formulated. D1 was the control group; D2–D5 were algae powder-replaced groups; and D6–D9 were mixture-replaced groups. Each diet was assigned randomly to three tanks each of which contained 30 sea cucumber juveniles. The results showed that: As the proportion of replacement of algae powder increased, the weight gain rate (WGR) and the specific growth rate (SGR) first increased and then decreased. D2 showed the highest WGR and SGR, which were significantly higher than those of D4 and D5 (P<0.05). As the proportion of replacement of the mixture increased, WGR and SGR decreased significantly (P<0.05). Replacement of algae powder caused decrease in the crude lipid, Gly, Met, and Cys, and it increased the contents of Phe and His; while replacement of mixture led to decrease in crude ash of the body wall and contents of Ser, Thr, Gly, Met, Lys, and His, and it increased the contents of Arg, Pro, Phe and Cys. Replacement of powder caused decrease in contents of Ca, Mg, Fe, Zn, Cu, Cr, Mn and Pb; Replacement of mixture led to decrease in contents of Ca, Mg, Zn, Cu, Cr and Pb, and it increased contents of Fe and Mn. Using WGR as the indictor, SAS REG analysis showed that the optimum proportion of replacement of algae powder with FSBM was 29.75%. NLIN analysis showed that the optimum replacement proportion of the mixture was 46.46%.