Rearing water quality and zootechnical parameters of Litopenaeus vannamei in rapid Biofloc® and conventional intensive culture system

Rapid Biofloc (R) Technology (R-BFT) is a bio-augmentation protocol designed for biofloc. In this study, five production cycles were conducted to investigate the effect of R-BFT on water quality, and the performance of Litopenaeus vannamei reared on an industrial scale in comparison with a control group (CSOP). Bacillus infantis was used to inoculate the R-BFT group at the start of each cycle, while the C-SOP was conditioned fortnightly with commercial probiotics following the standard operating procedure for intensive shrimp culture. The C/N balance was maintained at 15:1 in both treatments using molasses one hour after feeding. Zero-wastewater discharge was maintained throughout each cycle for the R-BFT group, while 20% water exchange was done in the C-SOP weekly. The result showed similarity in the mean values of temperature, pH, and salinity. However, phosphate concentration and biofloc volume were higher in the R-BFT compared to the control, while the reverse trend was observed for dissolved oxygen, nitrite, and ammonia. Although the final weight and weight gained were similar in the treatments, the quantity of feed fed per shrimp and feed conversion ratio were substantially reduced for the R-BFT (14.82 g and 1.52 respectively) compared to the C-SOP group (18.33 g and 2.49 respectively). Survival was significantly higher in the R-BFT (91%) compared to the C-SOP (66%), while the mean yield was 57% higher in the former compared to the latter. Thus, R-BFT substantially improved water quality and the zootechnical performance of L vannamei under intensive culture. (C) 2021 The Author(s). Published by Elsevier B.V.