EVALUATION OF DIETARY ASCORBIC ACID SUPPLEMENTATION IN PRATICAL DIETS FOR AFRICAN CATFISH Clarias gariepinus (BURCHELL 1822) FINGERLINGS.

摘要

The effect of dietary Ascorbic acid (Vitamin C) at inclusions levels of (0, 50, 100, 150 and 200mg AA per kg of feed) on the growth performance and nutrient utilization of African catfish Clarias gariepinus (Burchell 1822) fingerlings were investigated in a study that lasted ten weeks. Clarias gariepinus weighing 6.02±1.3 were randomly distributed into five treatment groups. A treatment contained three replicates of 10 fishes each. Results showed that L-ascorbic acid inclusion in the diet improved weight gain in Treatment 2, 3, 4 and 5. The highest mean weight gained (MWG) and protein efficiency ratio was recorded in treatment 4 fed a diet of 150mg AA/kg. Growth performance and nutrient utilization parameters such as specific growth rate (SGR), Feed Conversion Ratio (FCR), Protein Efficiency Ratio (PER) and Feed Efficiency (FE) in all the treatments were significantly different at (P < 0.05). After week 8, fish fed scorbutic diet in Treatment 1 (0mg/kg) began to develop clinical deficiency including lordosis, broken skull, pigmentation and feed refusal. In all parameters considered Treatment 4 fed 150mg AA/kg gave the best growth performance and nutrient utilization efficiencies, while fish in Treatment 1 fed scorbutic diet recorded the highest mortality of 30% and lowest growth performance and nutrient utilization efficiencies. However fish in Treatment 5 fed the highest level of ascorbic acid supplementation of ?200mg AA/kg did not perform better than fish in Treatment 4 fed 150mg AA/kg in terms of growth and nutrient utilization efficiencies.