Effects of live transfer on serum biochemistry and oxidative stress parameters in the Turkish Salmon candidate fish

Turkish salmon (Oncorhynchus mykiss) has significant economic importance in Turkish aquaculture and export and is a key species supporting sustainable production, particularly in the Black Sea Region. Live fish transfer between facilities is an unavoidable step in the production cycle and may induce physiological and biochemical stress responses. Understanding transfer-related stress is essential for maintaining fish welfare and improving production efficiency. In this study, the effects of live transfer on selected biochemical parameters, serum electrolytes, and oxidative stress indicators were investigated in Turkish salmon. A total of 30 healthy fish (400±50 g, 12 months old) were divided into a pre-transfer control group and a post-transfer group following road transportation. Serum glucose, urea, uric acid, AST, ALP, LDH, Fe, total protein, and cortisol levels were analyzed. Significant increases were detected in glucose, AST, iron, and LDH levels in the transfer group compared to the control group (p<0.001), while cortisol levels significantly decreased (p<0.001). In addition, total oxidant status (TOS) and oxidative stress index (OSI) values significantly increased (p<0.05). These findings indicate that live transfer significantly affects metabolic, enzymatic, and oxidative stress responses, and optimization of transfer protocols is critical for fish welfare and production success.