Evaluation of three diets formulated from local agroindustrial by-products for production of Oreochromis niloticus in earthen ponds

Three diets were evaluated for growth, production and economic performance of the Nile tilapia, Oreochromis niloticus, after a culture period of 160 days at the Aquaculture Research and Development Centre (ARDEC), Akosombo, Ghana. Locally available agro-industrial by-products were used to compound the diets. Wheat bran and rice bran were used as energy sources while fish meal and groundnut bran were used as protein sources. The crude protein level of the control diet and the test diets were 9 and 15 per cent, respectively. Results from the feeding trials showed that diet F1 performed best in most of the growth and feed utilization parameters tested (mean daily growth rate and mean net weight gain). However, there was no significant difference between the performance of diets F1 and F3 (P > 0.05). The control diet F2 was the most economical with respect to profit index and economy of weight gain. It cost ¢1041.00 to produce 1 kg of fish on diet F2, while the same weight of fish costs ¢2013.00 to be produced on diet F3. Considering the overall performance of the three diets in terms of feed utilization and production economics, diet F1 (wheat bran and groundnut bran) was the most cost-effective practical diet. It is recommended to fish farmers for cultivation of Oreochromis niloticus fingerlings (90-100 g) to a marketable size of about 220 g in 5 months.