THE EFFECT OF Tephrosia vogelii AQUEOUS EXTRACT ON THE GROWTH AND NUTRIENT UTILIZATION PARAMETERS OF Clarias gariepinus

The impact of sub lethal exposure of the aqueous extract of Tephrosia vogelii leaves on Clarias gariepinus was evaluated through the changes on the growth and nutrient utilization parameters of the fish when compared to the control group. Replicates of ten (10) juveniles of Clarias gariepinus were kept in test tank of glass aquaria tanks of size 30.5 x 30.5 x 46.2 cm each. A freshly prepared stock solution of aqueous extract of T. vogelii was dispensed into each of the three tanks at the following magnitudes of 0.91 mg/L, 1.82 mg/L, 3.64 ng/L and control 0.00 mg/L. Each treatment was in triplicate. Fish were fed to 5% body weight with 42% crude protein level commercial feed for eight (8) weeks. The weight gain of fish in each tank and treatment was obtained fortnightly. Dose dependent decreased was observed on the growth of C. gariepinus and in all the nutrient utilization parameters such as live weight gain (LWG), Specific Growth Rate (SGR), Feed conversion ratio (FCR)., Gross Feed Conversion Efficiency (GFCE), Feed Efficiency (FE), Protein Efficiency Ratio (PER) and Nitrogen Metabolism (Nm) were recorded. In Nigeria, because of cost implications and the need for higher returns on investment, farmers are increasingly depending on plant-based aqua feeds; a major problem associated with this development is that plant ingredients are rich in phyltic acid, which reduces the bioavailability of nutrients like minerals and protein to the fish, thereby causing aquaculture pollution. There is therefore need for research efforts to be directed towards producing aqua feeds that will increase the nutritive value of fish diet and increase profitability and productivity without degrading the environment.