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

Abstract

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, Haematology