Efficiency of intensive tilapia culture in earthen ponds applied biofloc technology (BFT), probiotics and off-flavor control methods

The aim of this study was to assess the efficiency of Nile and red tilapia cultured in intensive systems applied a combination of biofloc technology (BFT) and probiotics in earthen ponds with different methods to control the off-flavor problem. A growing-out experiment was conducted for 150 days in which both Nile tilapia (5.88 ± 0.59 g) and red tilapia (9.72 ± 0.72 g) fingerlings were randomly allotted into three replicates of earthen ponds which were subdivided into four treatment groups, including: off-flavor controlled by algae management in Nile tilapia ponds (NT - AM) and red tilapia ponds (RT - AM), and off-flavor controlled by active water exchange in Nile tilapia ponds (NT - WE) and red tilapia ponds (RT - WE). The results showed that water quality was maintained in suitable ranges for fish growth. There were no significant differences in growth performance (final weight, daily weight gain and specific growth rate) among all treatments (P < 0.05). Feed conversion ratio of Nile tilapia (1.28 - 1.31) was significantly lower than that of red tilapia (1.35 - 1.37) (P < 0.05). The survival ratio (about 80%) and extrapolated yield (21.50 tons/ha in 150 days) of fish was similar and high for both Nile and red tilapia. The quality of the harvested fish in term of condition factor, size even and off-flavor intensity was also excellent. The economic efficiency of red tilapia farming in this system was higher as compared to cage systems. This study clearly demonstrated that the technique of combined BFT and probiotic application in earthen ponds could contribute to the sustainable development of tilapia production in Vietnam by reducing production cost, saving water resource and avoiding environmental pollution.