Evaluation of biofloc meal as an ingredient in diets for white shrimp Litopenaeus vannamei under practical conditions: Effect on growth performance, digestive enzymes and TOR signaling pathway

Biofloc meal is a sustainable protein source of aquafeed, which has been verified by several previous studies under experimental conditions. This study evaluated the potential for the replacement of fish meal (FM) with biofloc meal (BM) in the diet of Litopenaeus vannamei under practical conditions. Two isonitrogenous (430 g kg− 1) and isolipidic (80 g kg− 1) diets were formulated, in which FM was replaced with BM at 0% and 15%. A commercial diet (CD) was used as reference. A 6-week feeding trail was conducted in concrete tanks (L 6 m × W 5 m × H 1.2 m) in green house with 8000 shrimps (initial weight 7.76 ± 0.61 g) per tank. Compared to FM, BM did not make negative effect on growth performance, digestive enzymes and TOR signaling pathway (P > 0.05). The parameters for growth performance of both FM and BM were significantly higher than that of CD (P < 0.05). Through real-time quantitative PCR analysis, relative expression levels of trypsin, tor and s6 k of CD were significantly down-regulated (P < 0.05), while 4e-bp expression level was not significantly affected by different diets (P > 0.05). Based on the above data, 15% replacement of fishmeal with biofloc meal did not make any difference on shrimps compared with fish meal group. Therefore, biofloc meal can be a sustainable ingredient of aquafeed for L. vannamei.