The efficacy of dietary Bambara nut (Vigna subterranean) in the growth performance and cost benefit of Clarias gariepinus culture was evaluated. To this end 35% CP diet was formulated using locally available ingredients. Five different diets were prepared from the 35% CP diet, replacing Soybean with Bambara nuts at different percentage as follows: T1 (0% BN: 100 SB), T2 (25% BN: 75% SB) T3 (50% BN: 50% SB), T4 (75% BN: 25% SB) and T5 (100% BN: 0% SB), and organoleptic assessment was conducted on the diets to determine texture, aroma and color, while chemical assessment was conducted to determine the nutritional qualities of the diets. One hundred and fifty (150) sub-adult Clarias gariepinus were distributed into five (5) groups in triplicates of ten (10) using fifteen aquaria, and were fed T1 – T5, for eight (8) weeks. Length and weight of fish were evaluated fortnightly to determine: weight gain, percentage weight gain, specific growth rate, performance index and condition factor. And the cost of feed and fish were determined to evaluate the cost benefits of the various diets. At the end of the feeding trials, data were collected and analysed using ANOVA followed by a Turkey multi-companism test with SPSS 170 package software and the following results were obtained: (1) the experimental diets T1-T5 had no effects on the physico-chemical properties of the experimental waters (2) the aroma of the experimental diets were less fishy, their texture ranges from fibrous to less fibrous and the colour from dark brown to light brown as the quantity of the Bambara nut in the diets increases (T1-T5). (3) The % lipid, % proteins and % fibre decreased as the quantity of Bambara nut increased in the experimental diets (T1-T5). (4) All the growth parameters and performance index increased significantly (P<0.05) as the quantity of Bambara nuts increased in the various diets (T1-T5):- Weight gain (WG): T1 (54.61+2.11), T2 (70.96+8.47), T3 (67.82+0.63), T4 (70.90+5.90) and T5 (77.35+3.81), Percentage weight gain (PWG): T1 (30.76+0.77), T2 (40.66+1.46), T3 (35.64+1.64), T4 (37.46+1.13) and T5 (44.84+10.30); Condition factor (CF): T1 (0.55+0.13), T2 (0.62+1.02), T3 (0.70+0.41), T4 (0.64+11.4) and T5 (0.64+4.30); Specific growth rate (SGR): T1 (0.34+0.02), T2 (0.43+0.05), T3 (0.42+0.01), T4 (0.43+0.02) and T5 (0.49+0.02); Performance index (PI): T1 (158.99+2.76), T2 (208.99+25.84), T3 (210.98+2.28), T4 (203.85+11.87) and T5 (213.13+4.30). The fish fed the Bambara nut diets (T2-T5) had enhanced net profit, profit index and benefit cost ratio, but lower economic weight gain. Bambara nut is unarguably a better feed ingredient than Soybean in the culture of Clarias gariepinus.
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