The response of Heterobranchus longifilis to the combination of fish meal at different levels with 40% of groundnut cake in its diet

A study was carried out on the response of Heterobranchus longifilis to the replacement of fish meal with 40% of groundnut cake in six experimental diets with varying protein levels (26.13%, 30.88%, 34.87%, 39.28%, 44.19% and 50.76%). The highest weight gain (72.46g), specific growth rate (SGR) (2.16), the best food conversion ratio (FCR) (1.91) and gross food conversion efficiency (GCE) (0.016) were recorded for fish fed diet with 50.76% (Diet VI) crude protein (40%groundnutcake and 38.15% fish meal). There was no significant difference (P>0.05) in the final weight offish fed the various diets. The diet with 44.19% (diet V) crude protein having 40% groundnut cake and 31.81 % fish meal gave a conversion ratio not significantly different (P>0.05) from fish fed diet VI and so it will be more economical to use this feed with lower fish meal. There was significant variation (P0.05) in the survival of fish fed the varying diets. The combination of groundnut cake and fish meal in the diet of H. longifilis that showed increased nutrient density and digestibility for optimal growth was obtained where the percentage groundnut cake/fishmeal was 40/31.81