Abstract:A 113-day experiment was conducted to investigate the efficiency of bio-floc aquaculture technology (BFA) for water quality control, disease resistance and growth of Litopenaeus vannamei in intensive farming systems at different stocking densities. The experiment was carried out on traditional farming treatments (TF200, TF400, and TF600) and BFA farming treatments (BF200, BF400, and BF600) at stocking densities of 200, 400 and 600 ind/m2, respectively. The six groups of shrimp were kept in 18 indoor cement tanks. Bio-flocs were developed in BFA farming tanks by adding sucrose and probiotic with very little water exchange during the experiment. Traditional farming treatments were cultured with traditional methods. It was found that the water quality, special growth rate and survival rate of the shrimp deteriorated or reduced with the increase of stocking density in all treatments. However, BFA at stocking density of 400 ind/m2 revealed advantage in closed farming systems of L. vannamei, compared with the traditional farming at the same stocking density (TF400). In BF400, the bio-floc volume increased by 3.25-fold, while the concentrations of nitrite-N and ammonia-N decreased by 67.9% and 72.7%, respectively; Water consumption decreased about 33%, and body weight, survival, special growth rate and production per unit of L. vannamei increased by 14.5%, 156.3%, 2.4%, and 194.1%, respectively. The production of BFA farming at stocking density of 400 ind/m2 (BF400) was 4.01±0.94 kg/m2, showing the best environmental and production effect.
