Digestibility coefficients of processed jackbean meal Cannavalia ensiformis (L.) DC for Nile tilapia, Oreochromis niloticus (Linnaeus, 1758) diets

A study was conducted to determine in-vivo apparent digestibility coefficient of nutrients in processed jackbean meal. Acid Insoluble Ash (AIA) was used as an indicator. The test diets consist of the seed meal replacing soybean meal at 10, 20, 30 and 40% to serve as test diets D10, D20, D30, and D40 respectively. A diet called as diet CTR, without jackbean meal served as control. These diets were fed to  Tilapia Oreochromis niloticus fingerlings (6.37 ± 0.07 g) in a glass tanks for 5 weeks. Faecal collection was made by siphoning after four hours of each feeding. Proximate analysis of both diets and faecal samples were carried out for crude protein, lipid, crude fiber, energy, and AIA. These were used to calculate the digestibility coefficient of nutrients. There was no significant difference (p > 0.05) in lipid and organic matter digestibility of the fish fed control diet and test diets. Significant (p < 0.05) variations occurred in nitrogen-free extracts, protein and crude fiber digestibility of fish fed control diet and the test diets.   Key words: Digestibility, in vivo, jackbean, Oreochromis niloticus.