Effect of varying proportions of the daily feed rations on the performance of Juveniles of Clarias gariepinus (Burchell, 1882)

Abstract

African catfish Clarias gariepinus (Burchell, 1882) constitutes a bulk of farmed freshwater fish, particularly in Africa. Its optimal production relies on an optimal feeding regime as feed covers about 50% of operation cost. Studies on feeding regimes have mostly been on feeding frequency and the daily required rations. This study was therefore designed to evaluate the impact of varied proportions of normal daily rations on the performance of C. gariepinus juveniles. Clarias gariepinus Juveniles of 17.6 ± 3.7 g were stocked at a density of 15 juveniles per 50 L of water in 80 L plastic tanks and cultured indoors for 42 days. They were fed a standard specific feed at 5% total biomass three times daily (8:00, 13:00 and 18:00). Treatment 1 received 33.33% of its daily ration at each feeding period, while treatments 2 and 3 received (50%, 25% and 25%) and (25%, 25% and 50%) of the daily rations at 8:00, 13:00 and 18:00, respectively. Fish biomass and survival rate were determined weekly and individual fish weights and lengths were determined at the end of the experiment. Water was aerated continuously and half the volume was renewed daily; temperature and pH were monitored twice daily. The specific growth rate, weight and length gained were best in treatment 3 although not significantly different (p>0.05) among treatments. However, feed conversion ratio and condition factor in treatment 3 were significantly (p<0.05) better when compared to treatments 1 and 2 although temperature and pH in the different treatments were not significantly different (p>0.05). The estimated investment cost was 3891, 4136 and 3907 FCFA, with profit index of 0.95, 0.87 and 1.09 in treatments 1, 2 and 3, respectively. Therefore, administering about 50% of the daily ration in the evening as was the case in treatment 3 is more profitable in the culture of C. gariepinus juveniles.