The Potential of Groundnut (Arachis hypogaea L.) By-Products as Alternative Protein Sources in the Diet of Nile Tilapia (Oreochromis niloticus)

Abstract

The nutritional suitability and cost effectiveness of groundnut cake (GNC) and groundnut husk (GNH) as protein sources in the diet of Nile tilapia (Oreochromis niloticus), mean initial weight 4.24 ± 0.20 g, was evaluated over a 56-day growth period. Five isonitrogenous (320 gkg−1), isolipidic (100 gkg−1), and isoenergetic (18 KJg−1) test diets were formulated in which GNC proteins replaced fish meal (FM) protein at levels of 25% and 50%, and GNH protein at 10% and 20%. The control diet had FM as the sole protein source. The growth experiment was conducted in plastic tanks in a recirculation system; each dietary treatment was in triplicate. After feeding fish at 4%–6% body weight per day, GNC and GNH protein replacements up to 50% and 20%, respectively, did not significantly (P < 0.05) affect growth and feed utilization. The study indicated that GNC and GNH protein could replace at least 50% and 20% of fish meal protein, respectively, in the diet of O. niloticus fingerlings without adversely affecting growth, feed efficiency, whole body composition, and nutrient digestibility. Generally the GN by-products-based diets were more cost-effective than the fish meal-based diet, particularly GNH replacing 20% fish meal protein.