ARS | Publication request: INTERACTION BETWEEN DIETARY LEVELS OF VITAMIN C AND E ON GROWTH AND IMMUNE RESPONSES IN CHANNEL CATFISH ICTALURUS PUNCTATUS

Submitted to: Aquaculture America Conference
Publication Type: Abstract Only
Publication Acceptance Date: October 1, 2005
Publication Date: February 3, 2006
Citation: Aksoy, M., Lim, C.E., Li, M.H., Klesius, P.H. 2006. Interaction between dietary levels of vitamin C and E on growth and immune responses in channel catfish Ictalurus punctatus. Aquaculture America Conference. Las Vegas, NV.

Technical Abstract: Vitamins C (L-ascorbic acid) and E ('-tocopherol) are dietary essential for most aquacultured species. It has also been demonstrated that these vitamins play an important role in the functioning of the immune system when supplied in the diet at levels above the requirements for normal growth and development. Synergistic effects of these vitamins have been also reported in some fish species. Thus, this study was conducted to evaluate the effect of dietary levels of vitamins C and E on growth performance and immune response of channel catfish. A basal practical diet containing 35% protein and 2900 kcal DE/kg was supplemented with three levels of vitamin C (0, 100, 2000 mg/kg diet) and three levels of vitamin E (0, 50, 500 mg/kg diet) at each level of vitamin C (3 x 3 factorial experiment). Each diet was fed to juvenile channel catfish in triplicate aquaria to apparent satiation twice daily for 12 weeks. Results indicate that the amount of vitamin E contained in the basal diet (23.1 mg/kg) was sufficient to promote good growth, feed efficiency and survival of juvenile channel catfish. However, vitamin E supplementation (50-500 mg/kg diet) was needed to maintain high levels of white blood cell count, hemoglobin, hematocrit and liver storage of vitamin E. Supplementation of vitamin C (100 mg/kg) to the basal diet containing 10.5 mg/kg was required for good growth, feed efficiency and survival, normal bone formation and improved serum protein content. A dietary vitamin C level of 2000 mg/kg was needed for maximum erythropoiesis (erythrocyte count and hemoglobin) and liver storage of both vitamins C and E. Superoxide anion production by leukocytes was significantly stimulated by supplementation of both vitamins but their interaction had no effect on this parameter. Dietary levels of vitamins C or E and their interaction had no effect on macrophage chemotaxis ratio and phagocytosis. The interaction between dietary levels of vitamin C and E had no effect on weight gain, feed efficiency, survival, hemoglobin, hematocrit, tissue levels of vitamins C and E and serum protein but did significantly effect red blood cell and white blood cell counts.