Evaluation of Viligen® NE as a feed additive for Pacific white shrimp reared in a biofloc system during the nursery phase

Abstract The aim of this study was to evaluate Viligen® NE (Alltech®, USA) as a feed additive for Penaeus vannamei reared in a biofloc system during the nursery phase, focusing on growth performance, intestinal microbiological analysis, and resistance tocold challenge. Shrimp post-larvae (41 mg) were fed for 6 weeks with four experimental diets: (a) 0.5 g Viligen® NE kg⁻ 1 , (b) 1 g Viligen® NE kg⁻ 1 , (c) 2 g Viligen® NE kg⁻ 1 , and (d) a control diet (0 g Viligen® NE kg⁻ 1 ). The experiment was conducted in quadruplicate, totaling 16 experimental tanks, with a stocking density of 2000 post-larvae m⁻ 3 . Shrimp growth performance parameters were positively influenced by the inclusion of Viligen® NE in the diet. Polynomial regression indicated an optimal inclusion level of 1.17 g kg⁻ 1 for maximizing specific growth rate and weight gain. Additionally, supplementation at 1 g kg⁻ 1 enhanced shrimp resistance to cold challenge. However, no significant differences were observed in intestinal counts of total heterotrophic bacteria or Vibrio spp. among treatments. In conclusion, dietary supplementation with Viligen® NE at an optimal level of 1.17 g kg⁻ 1 improved growth performance, and 1 g kg⁻ 1 enhanced cold challenge resistance of nursery-phase shrimp reared in a biofloc system.