The Feasibility of Small-Scale Hapa Culture of Tilapia Oreochromis niloticus as an Additional Income Source for Rice Farmers in Northeast Thailand

Abstract

In Northeast Thailand, hapa culture of tilapia may provide interesting perspec­tives for rural development. Besides being a suitable method for managing fish produc­tion in village ponds, it may generate additional income for local rice farmers. In the present study, rice farmers raised tilapia Oreochromis niloticus in small hapas (water volume 8 m3) in village ponds. Fish were fed a commercial diet (protein content 35%). Tilapia stocked at an initial weight of 50 g attained a mean specific growth rate of 1.46% of the body weight (BW) per day. Market size was attained after an average rearing time of 85 days. The mean feed conversion ratio was 1.4. The economic analysis was based on the observed plus four theoretical produc­tion scenarios. Investment costs were about 5% of total operating costs. Fingerling costs (about 25% of total costs) could be considerably reduced when fingerlings were collected from backyard ponds or from the hapas (•wild spawning•). Feed costs amounted to 70% of total costs but could be reduced by optimizing the feeding regime and home-mixing of fish feed. Stocking weight was not an important economic variable but affects the rearing period to reach market size. Shorter rearing periods gave higher daily gross margins, and were preferred by local rice farmers. A rearing period of 100 days may be a suitable compromise between the farmers' preference for short production cycles, the harvest size of the fish and the profitability Large of the hapa culture. Large fingerlings (W0= 50 g), stocked at a density of 14 fish·m.3, may reach a suitable market size of 216 g in 100 days. If smaller fingerling& are stocked, two rearing cycles will be needed to reach market size. In this way, rice farmers may increase their household income by about 20%.