Soybean protein concentrate in Pacific white shrimp reared in bioflocs: effect on health and vibrio challenge

ABSTRACT. Litopenaeus vannamei shrimp were reared in a bioflocs system and fed different levels of soybean protein concentrate as a replacement for fishmeal, and both immunological parameters of this marine shrimp and its resistance to Vibrio sp. infection (CPQBA 378-12 DRM01) were evaluated. Four different diets were formulated with 0, 33, 66 and 100 % of soybean protein concentrate as a substitute for fishmeal. Shrimp were reared in a biofloc system in twelve 800 L tanks (250 shrimp m-3) maintained at constant aeration and temperature. After 42 days, 36 animals (14.21 ± 0.89 g) per treatment were challenged with Vibrio sp. (1 x 105 CFU mL-1 - LD10), and hemolymph was collected before and after challenge to perform immunological assays (agglutination titer, concentration of protein and phenoloxidase activity). Shrimp fed with the experimental diets showed no difference in their resistance to infection and haemato-immunological parameters. Thus, rearing L. vannamei in a biofloc system on diets containing either partial or total replacement of fishmeal for soybean protein concentrate did not affect either immunocompetence or susceptibility to infection.