Performance of locally formulated feeds for rearing of African catfish in Tanzania
Fisheries is an important food production sub-sector, providing almost 20% of the world’s protein supply; however, the trend in fish production from capture fisheries has reached its limits due to overfishing. A study was
conducted to evaluate the performance of two locally formulated feeds as possible replacements for an imported costly commercial feed (CMF) commonly used in rearing of African catfish (Clarias gariepinus Burchell) in
Tanzania. Two feed types, namely TAF 1 and TAF 2, denoting TAFIRI feed type 1 and 2 were formulated from fish meal (Rastrineobola argentea) and soybean (Glycine max L.), respectively. Nine concrete tanks of 12 m3
each were stocked with 320 catfish fry each, and fed with formulated feeds at 5% of their mean body weight for four months. Water in the tanks was wholly flushed out on a weekly basis and fish sorted for the fast growers to
reduce cannibalism. On a monthly basis, fish were randomly sampled for body length and weight. The mean values for temperature, dissolved oxygen and pH ranged from 21.62±0.04 to 25.16±0.05 oC, 5.43±0.05 to
5.7±0.07 mg O2 L-1, and 6.5±0.05 to 6.61±0.03, respectively. Feed TAF 1 was the best performer with weight gain of 33.72±0.89, average daily gain of 0.28±0.01, FCR of 1.35±0.05 and specific growth rate of 4.61±0.04.
Fish fed on the commercial feed performed the poorest, with weight gain of 6.17±4.8, average daily gain of 0.05±0.004, FCR of 1.56±0.11 and specific growth rate of 2.98±0.05. Results from this study suggest that locally formulated feeds can cost effectively be used for the rearing of African catfish in Tanzania.
Key Words: Clarias gariepinus, dissolved oxygen, Glycine max