Optimizing feed restriction strategies for profitable Oreochromis niloticus culture in floating cages in riverine ecosystems

Abstract

High feed cost is a major obstacle for promoting the growth of nutrient-rich fish species like Nile tilapia (Oreochromis niloticus) in cage aquaculture. To address this issue, cage farming of O. niloticus was studied for a 75-day period in the Gurukchi River of Bangladesh. Three different feeding strategies (FS) were tested in floating cages: FS5- weekly restriction on feed supply for two days, FS6- weekly restriction on feed supply for one day, and FS7- no weekly restriction on feed supply, with three replications for each treatment. Water quality parameters were monitored weekly and found within suitable levels for fish cultivation. The analysis of length–weight relationship and the condition factor of O. niloticus showed positive allometric growth regardless of the diverse feeding tactics employed that consistently exhibit stability across all treatments. Both FS6 and FS7 had significantly higher (p < 0.05) final individual length, final individual weight, net yield, total yield, and specific growth rate than FS5. FS6 yielded significantly higher fish production with significantly lower feed conversion ratio than FS7. Economic analysis revealed the highest benefit–cost ratio and net revenue in FS6, recommending its use to minimize the need for supplemental feed and reduce production costs in tilapia cage culture.