Growth performance and survival rate of Clarias gariepinus juveniles fed different levels of aflatoxin – contaminated feeds

Abstract

This experiment was conducted to evaluate the effects of different levels of aflatoxin- contaminated feed (0% toxigenic maize, 25% toxigenic maize +75% good maize, 50% toxigenic maize+50%good maize, 75% toxigenic maize +25% good maize and 100% toxigenic maize) on growth, survival, haematology and histology of Clarias gariepinus juveniles. Ten Clarias gariepinus juveniles with average weight of 42.81±0.01g were subjected to five treatments, with two replicates for each. The fish were fed twice daily at 5% body weight of 40% crude protein for six weeks. Growth performance indices such as Mean Weight Gain (MWG), Specific Growth Rate (SGR), Survival Rate (SR) and Feed Conversion Ratio (FCR) were determined. Haematological parameters such as Packed Cell Volume (PCV), Red Blood Cell (RBC), Haemoglobin (Hb) content and lymphocytes were evaluated. Data resulting from the experiment were subjected to descriptive statistics and ANOVA at P = 0.05. Results showed that highest mean weight gain (107.00± 10g), specific growth rate (0.03±00g), survival rate (60.00%) and feed conversion ratio (0.68±0.05) were observed with control diet. MWG, SGR, SR and FCR were significantly (p<0.05) higher in control diet compared with the other treatments. Also, packed cell volume, red blood cell (count) were higher in the control compared with other treatments, red blood cell counts were significantly different (p< 0.05) in control than other treatments. Lymphocytes were better in control and treatment 1 (25% toxigenic maize + 75% good maize) while decreased value were observed in the other treatments which indicate reduction in immune response of the fish. The control diet and treatment 1 were significantly (p<0.05) higher than other treatments but no significant difference (p>0.05) were recorded between control and treatment 1 (25% toxigenic maize + 75% good maize). Histology analyses of the liver and intestine of aflatoxin – contaminated feeds revealed severe degeneration and diffuse necrosis and mucosal erosion respectively. This study concludes that presence of aflatoxin contaminated feed affect the survival and growth performance of Clarias gariepinus juveniles

Keywords: Growth, Aflatoxin- contaminated feeds, Clarias gariepinus, Haematology Survival