Evaluation of fermented African mesquite seed (Prosopis africana) on growth and nutrient digestibility of Nile tilapia (Oreochromis niloticus) fingerlings

Production of cheap and quality dietary protein to replace the expensive conventional protein was studied in an 84-day feeding trial of Nile tilapia Oreochromis niloticus. African mesquite (Prosopis africana) seeds were subjected to fermentation processes and four iso-nitrogenous diets (35% crude protein) were formulated to contain graded levels of fermented African mesquite seed meal (FMS) to replace soybean meal (SBM) at four inclusion levels (0%, 15%, 30% and 45%) replicated in a completely randomised design. Proximate analysis showed increased in crude protein (35.10% to 41.29%), amino acids concentration, minerals content (calcium and phosphorus) while there were reductions in crude fibre (7.79% to 2.13%), crude lipids (4.02% to 2.67%) and anti-nutritional factors of FMS. The highest protein digestibility of 83.35% was recorded in FMS30 while FMS15 showed the least (77.07%). Carcass compositions were affected by diets composition. The minimum feeding cost of US$ 0.88 kg−1 was registered in FMS45 while FMS15 recorded the highest value of US$ 1.37 kg−1. In conclusion, 45% of FMS could replace SBM without compromising growth performance of Nile tilapia.