Saccharomyces crevices and Bacillus spp. effectively enhance health tolerance of Nile tilapia under transportation stress

Abstract

© 2020 Elsevier B.V. The effects of added probiotics on growth performance, blood chemical, and hematological responses; as well as immune-related gene expression in Nile tilapia (Oreochromis niloticus) under transportation stress were evaluated. Fish were treated over a period of 120 days in three groups: T1, the control group (no probiotic), T2, 5.6 × 108 cfu g−1 of Saccharomyces cerevisiae, and T3, 1 × 106 cfu g−1 of Bacillus spp. The fish were then exposed to the transportation stress experiment for four hours (h). The resulted revealed that there were no significant differences in survival rate during and after transportation in all treatments. However, the survival rate of the control group significant decreased (p <.05) after 24 h post transportation stress, and significantly higher rate of cortisol, glucose, aspartate aminotransferase (AST), and alanine aminotransferase (ALT) were observed in the T1 group, compared to the T2 and T3 groups. However, significantly lower malondialdehyde (MDA) was found in T3 compared to those of T1 and T2 after 24 to 72 h post-transportation. The expression of heat shock proteins (Hsp70) and tumor necrosis factor-alpha (TNF-α) levels in the control group were significantly higher (p <.05) than those of T2 and T3 groups, especially at 0 h post-transportation stress. No significant differences in lysozyme activity and hematological profiles were detected between the control (T1) and probiotic groups (T2 and T3). In conclusion, Nile tilapia reared for 120 days in aqueous probiotic showed significantly improved health tolerance under transportation stress.