The dietary requirement of juvenile grass shrimp (Penaeus monodon) for vitamin D

Two 8-wk experiments were conducted to determine the adequate level of dietary vitamin D for juvenile grass shrimp (Penaeus monodon). In Experiment 1, purified diets with six levels (0, 0.1, 0.5, 2.5, 12.5 and 62.5 mg/kg diet) of supplemental ergocalciferol and cholecalciferol were fed to P. monodon (mean weight 0.19 +/- 0.02 g). In Experiment 2, we used 0, 0.05, 0.1, 0.2, 0.3, 0.6 and 1.0 mg/kg of supplemental cholecalciferol in basal diet fed to the shrimp (mean weight 0.25 +/- 0.03 g). In both experiments, shrimp fed vitamin D-deficient diets grew poorly. In Experiment 1, poorer growth performance was observed in shrimp fed diets containing ergocalciferol compared with those fed the diets containing cholecalciferol. In Experiment 2, weight gain was highest in shrimp fed the diet supplemented with 0.2 mg cholecalciferol/kg diet, followed by the groups fed 0.1 mg/kg, then 0.3 mg/kg, 0.05 and 0.6 mg/kg, 1.0 mg/kg, and finally the unsupplemented control group. The differences among these groups were significant (P < 0.05). The feed efficiency ratio and alkaline phosphatase activity generally followed the same pattern as the weight gain. Analysis by brokenline regression of weight gain and alkaline phosphatase activity of the shrimp in Experiment 2 indicated that the adequate dietary cholecalciferol concentration for growing P. monodon is approximately 0.1 mg/kg.