Abstract:
The study was conducted at the Aquaculture Research and Development Centre at Akosombo to observe the growth performance of fry and fingerlings of O. niloticus; and also assess the cost-effectiveness of the different dietary treatments. In experiment 1, four isonitrogenous (36% crude protein) and isoenergetic (gross energy 18 MJ/kg) diets were formulated to contain agro-industrial by-products including: wheat bran (diet 1), pito mash (diet 2), rice bran (diet 3) and groundnut bran (diet 4) and fed to fry of O. niloticus (average initial weight 0.11 ± 0.01 g) stocked at 50 m-3 in out-door hapas for 8 weeks. In experiment 2, four isonitrogenous (30% crude protein) and isoenergetic (gross energy 18 MJ/kg) diets were formulated from the same by-products as in experiment 1 and fed to O. niloticus fingerlings (average initial weight 7 ± 0.23 g) stocked at 20 m-3 for 24 weeks.
Growth performance was similar (P > 0.05) for fry O. niloticus among all treatments. However, incidence cost was highest for diet 4 and lowest for diet 2. Fish fed on diet 2 had the highest (P < 0.05) profit index and those fed on diet 4 had the lowest. Growth performance in fingerlings was highest (P < 0.05) in diet 1 and least in the control. Whiles incidence cost was highest (P < 0.05) for fish fed diet 4 and lowest (P < 0.05) for fish fed diet 2.
In conclusion, the growth performances were similar (P > 0.05) for fry of O. niloticus among all treatments. For O. niloticus fingerlings, diet 1 produced the fastest growth. Diet 2 was the most cost-effective diet. From this study, diets 1 and 2 for rearing of O. niloticus are recommended for feeding.
