Effects of different dietary lipid levels and fatty acids profile in the culture of white shrimp Litopenaeus vannamei (Boone) in biofloc technology: water quality, biofloc composition, growth and health

The objective of this study was to evaluate the influence of different dietary lipid and fatty acids on the nutritional value of bioflocs used as a feed, as well as shrimp performance and health. A total of 1800 Litopenaeus vannamei juveniles (2.87 +/- 0.01 g) were cultured in biofloc technology, with a density of 200 shrimp m(-2), and fed with three isoproteic experimental diets at different lipid levels (85 g kg(-1), 95 g kg(-1) and 105 g kg(-1)); each treatment was performed in triplicate. After 61 days, no significant difference was observed (P > 0.05) among the water quality parameters. For the shrimp performance, significant difference was observed (P = 0.011) among the values of survival, where treatments with lower lipid levels had higher survival (92.5 +/- 3.5% and 91.0 +/- 2.5%). Although there are significant differences in survival, no significant differences in the total haemocytes count (THC) were observed. For other growth performance, no differences were observed (P > 0.05). A positive correlation (r = 0.75) has been observed between the dietary oleic acid and bioflocs. The bioflocs showed 'long-chain' polyunsaturated fat acids (lcPUFA), especially arachidonic acid. The shrimp showed similar growth and stayed healthy at the end of the experimental period.