Growth, Feed Utilization and Haematology of Clarias gariepinus (Burchell, 1822) Fingerlings Fed Diets Containing Different Levels of Vitamin C

Abstract

Problem statement: In an effort to increase growth, improve feed utilization, reduc e stress and prevent certain diseases , a 14 week feeding trial was conducted to determine the effects of different levels of dietary vitamin C (ascorbic aci d) on growth, feed utilization and hematological changes in Clarias gariepinus fingerlings. Approach: Diets were formulated to contain 0, 50, 100, 150, 500, 1000 and 1500 mg L-ascorbic acid kg -1 of feed contributing 0, 0.05, 0.10, 0.15, 0.5, 1.0 and 1.5% to the formulated diets respectively. Fish of mean weight 10.12±0.7 g were fed on experimental diets in triplicate groups. Weight gain of fish fed diet with 0% of vitamin C were significantly (p 0.05) differences in weight gain amo ng the fish fed diets containing 0.05, 0.10 and 0.15% of vitamin C. Generally, fish fed vitamin C s upplemented diets showed better growth rate, feed conversion ratio and protein efficiency compared wi th those without vitamin C supplementation. Results: The results of hematological analyses of fish showe d that red blood cell, white blood cell, haemoglobin concentration and packed cell volume were not significantly (p>0.05) affected by vitamin C supplemented diets. Fish fed the vitamin C-free d iet begin to show deficiency signs such as erratic swimming, flashing, skin darkening and reduced growth at 12 weeks of feeding trial. Conclusion: This study indicated that 50 mg kg -1 of ascorbic acid is sufficient to prevent C. gariepinus fingerlings from developing clinical symptoms relating to vitamin C deficiency. A mega dose of 1500 mg kg -1 of