Determination of Optimum Calcium and Phosphorous Ratio for the Production of African Catfish Clarias gariepinus (Burchell, 1822)

Optimum calcium-phosphorus (Ca/P) ratio for the growth of African catfish was investigated over a 70-day period with a basal diet formulated and supplemented with Ca/P ratios of (0:0, 1:0.5, 1:1, 2:1.5, 3:1 and 3.5: 1.5) respectively. The results showed that the mean weight gain and specific growth rate increased from the fish fed the control diet up to the fish fed diet with Ca/P ratio of 2:1.5, and then declined consistently to the fish fed diet with Ca/P ratio of 3.5:1.5. Addition of Ca and P in the diets significantly increased the carcass ash, while feeding the fish with the control diet supposed to be imbalance in Ca/P ratio elevated the carcass fat and moisture. The increase in carcass ash consequently resulted in increase (P 0.05) in carcass minerals (Ca, Mg, P, Zn and Fe) in relation to fish fed the control diet. In conclusion, the study suggests Ca/P ratio of 2:1.5 (1.33:1) as the optimum for the production of African catfish.