Response of African Catfish, Clarias gariepinus; (Burchell, 1822) to Diets of African Yam Bean, Sphenostylis stenocarpa Subjected to Two Processing Methods

Response of Clarias gariepinus to diets of African yam bean (Sphenostylis stenocarpa) (AYB) subjected to two processing methods was assessed. Mature AYB was boiled, fermented and processed into meals. Seven diets were formulated to contain 44.07 ±0.48% crude protein and 19.03±0.05 kJ g-1 gross energy respectively. Fishmeal in the diets was substituted with each of the two processed AYB meals at 40%, 45% and 50% levels. Nine fingerlings (initial average weight 1.36±0.02g) were stocked per experimental tank. Experimental diets were fed to triplicate groups of catfish fingerlings at 10% body weight for 56 days. Results showed that specific growth rate (SGR) and protein production value (PPV) were highest at 45% replacement of fermented AYB (3.32±0.20; 49.30±17.94) compared to control (3.17±0.44; 38.89±12.49). Mean values for haematological parameters (PCV, HB, WBC and RBC) significantly increased (P<0.05) above the initial status and control group. Haematological values for fish fed 40% inclusion level of fermented and boiled AYB were the highest. This study shows that AYB processed by fermentation and boiling were effective in enhancing fish growth. However, based on SGR and PPV results Fermented AYB should not be used in Clarias gariepinus diets beyond 45%inclusion level.Key Words: African Catfish, Alternative Protein Sources, African Yam Beans, Haematolog

Preliminary Evaluation of Jackbean (Canavalia ensiformis L.DC) Seed Meal as a Substitute for Fishmeal in diets for Clarias gariepinus (Burchell, 1822)

Jackbean (Canavalia ensiformis) is an under-utilized legume with crude protein content and amino acid profile that make it a potential ingredient in the tropics as substitute for fish meal in fish diets. This study assesses the potentials of Jackbean seed meal (JBSM) for partial replacement of fish meal in diets of Clarias gariepinus. Fishmeal in control diet was replaced progressively (10%, 20% 40% and 60%) by raw JBSM, 30-and 60-minute boiled JBSM. Test fish in each tank were fed 3% of their biomass twice daily for 56 days. Fish fed control diet had the best performance (Specific growth rate 1.6; Feed conversion ratio 1.88: Protein efficiency ratio 1.74). Specific growth ratio and PER of fish groups fed test diets were inversely related to the dietary levels of JBSM. The same trend applied to protein and fat contents of the fish carcass. Feed conversion ratio however had the reverse trend. Fish fed diets with up to 20% fishmeal substituted by 60 minute boiled JBSM had protein content similar to those fed the control diets (