Improvement of brown shrimp (Penaeus aztecus) culture parameters through dietary enriched synbiotic in a biofloc system

This study aimed to determine the potential efficacy of dietary prebiotics, probiotics, and synbiotic on growth performance, total hemocyte count (THC), hepatopancreas histology, and gut microbiota composition of brown shrimp (Penaeus aztecus) under biofloc technology (BFT) conditions for 84 days. Seven feed additive groups were formed as C: control group with no feed additive, P: probiotic mixture (1 mL, 1 × 10⁹ CFU/100 g feed, Lactobacillus plantarum, L. acidophilus, L. salivarius, and Bacillus subtilis), A: 0.2 g Arthrospira/100 g feed, S: P + A, ES1: P + A + 0.1 g MOS/100 g feed, ES2: P + A + 0.2 g MOS/100 g feed, ES3: P + A + 0.3 g MOS/100 g feed. At the end of the trial, P, A, and S showed an intermediate effect on final body weight (FBW) compared to the control group, while FBW significantly increased in the ES1, ES2, and ES3 groups (P < 0.05). Gut microbiota diversity revealed a predominance of Proteobacteria phylum and a decrease in Bacillota phylum in dietary prebiotic, probiotic, and synbiotic treatments. The number of B cells increased in the hepatopancreas of brown shrimp fed diets containing feed additives, indicating a significant effect on hepatopancreatic tubules. THC levels of the shrimps in the experimental groups increased, and the highest values were reached in shrimps fed with synbiotic diets (P < 0.05). In conclusion, it can be concluded that enriched synbiotic diets supplemented with probiotic mixture, Arthrospira, and mannan oligosaccharide can promote healthy growth for brown shrimp under BFT conditions.