Effects of dietary mannan oligosaccharides on growth, non-specific immunity, and intestinal health in juveniles of the Japanese sea cucumber (Apostichopus japonicus)

We investigated the beneficial dietary effects of mannan oligosaccharide (MOS) on sea cucumber ( Apostichopus japonicus ) and the optimum dietary level of MOS. Juvenile sea cucumbers (initial mean weight of 1.50 ± 0.00 g, N = 225) were fed once daily for 60 days in tanks with aerated seawater (3 tanks/diet; 15 inds/tank) on feeds supplemented with 0 g/kg (M0), 4 g/kg (M1), 8 g/kg (M2), 12 g/kg (M3), and 16 g/kg (M4) MOS. The results showed that 4 g/kg of MOS in feeds significantly improved the growth performance of sea cucumber. There was a positive linear and quadratic correlation between the total superoxide dismutase (T-SOD) activity and dietary MOS level (linear, P = 0.043, R 2 = 0.279; quadratic, P = 0.009, R 2 = 0.545). Compared with the control group, 8 g/kg MOS significantly increased the protease (PRO) and amylase (AMS) activities ( P