Evaluation and potential of cocoyam as carbohydrate source in catfish, (Clarias gariepinus [Burchell, 1822])

The cost of feeding fish is about 60% of the total recurrent cost of fish farming, hence a need for non-conventional and cheaper ingredients to substitute the expensive ones. Seventy five juvenile of Clarias gariepinus mean weight 9.86 g were randomly stocked at 5 juveniles per tank of dimension 40 x 56 x 31 cm and fed five isonitrogenous and isocaloric diets containing graded levels of cocoyam at 0, 25, 50, 75 and 100% substituted for maize meal over a period of 70 days. The result of the experiment showed that diet 1 had the highest specific growth rate (SGR), 1.47%/day and diet 4 had the lowest of 0.89%/day. The best food conversion ratio (FCR), 1.81 was from diet 2 while the worst of 2.91 was from diet 4. Highest mean yield, net profit, benefit cost ratio and profit index of 26.58, 4.93, 1.23 and $16.11 respectively, were from diet 2 while the lowest of 22.91, 0.49, 1.02 and $9.47 were from diet 4. All indices considered were significantly different (p<0.05) between <50% cocoyam and >75% cocoyam treatments. The study showed that 25% replacement of cocoyam for maize is recommended for growth and economic benefit for sustainable aquaculture.