Effects of dietary addition of vitamins C and D₃ on growth and calcium and phosphorus content of pond-cultured channel catfish

Fingerling channel catfish, Ictalurus punctatus, were fed one of three diets: one deficient in vitamin C (ascorbic acid), one deficient in vitamin D₃ (cholecalciferol), or one containing both vitamins. Semimonthly from May to September and monthly from September to February, calcium and phosphorus were determined in eviscerated bodies and fat-free skeletons by neutron activation analysis. Body weight gains, survival rate, and feed conversion rates were determined for the May to September period. Fish on the three diet regimens showed no significant difference in weight gain, feed conversion, or survival. Interactions between sampling date and diet indicated no correlation between vitamin C or D₃ and the calcium and phosphorus in eviscerated bodies and fat-free skeletons of the fish.