Taurine Intake Alleviates Oxidative Damage During Transportation in Culter alburnus

Live fish transport easily induces severe physiological stress, marked by pronounced oxidative damage and significant mortality, leading to substantial economic losses annually. Here, we evaluated the effects of taurine intake on alleviating stress response during transportation of Culter alburnus. Juvenile fish were fed diets containing 0 (control), 0.5, 1.0, 1.5, or 2.0 g/kg taurine for 8 weeks before undergoing 12 h of simulated transport. The results showed that taurine supplementation significantly improved growth performance in a dose-dependent manner. During transportation, the deterioration of water quality and the damage of gill tissue decreased with the increase in concentration. The determination of catalase (CAT), glutathione peroxidase (GSH-Px) and malondialdehyde (MDA) showed that 2.0 g/kg taurine improved antioxidant capacity. The high-concentration taurine group enhanced the activities of immune enzymes such as acid phosphatase (ACP) and alkaline phosphatase (AKP), while the activity of total nitric oxide synthase (T-NOS) was inhibited. The antioxidant immune effect of the 0.5 g/kg and 1.0 g/kg concentration groups was not obvious. Transcriptome analysis revealed that 2.0 g/kg taurine enhanced the antioxidative stress capacity of C. alburnus by upregulating the expression of immune-related genes (TLR5, Il12b) and activating the Toll-like receptor signaling pathway as well as the cytokine-cytokine receptor interaction pathway. These findings demonstrated that dietary taurine improved resilience to transport stress in C. alburnus.