Effects of xylazine on blood biochemical, oxidative, and haematological to responses to transport distance stress in day-old broiler chicks

Transport of day-old chicks is a major concern in the poultry industry, as it induces stress that can impair performance and health. This study investigated whether xylazine, an alpha-2 adrenergic agonist that reduces metabolic rate, could modulate stress responses in day-old broiler chicks during simulated road transport. A total of four hundred day-old broiler chicks were allocated in a 3 × 4 factorial design consisting of three transport distances (0, 100, and 200 km) and four injection treatments (control, saline, xylazine at 0.5 mg/kg BW, and xylazine at 1 mg/kg BW). The results showed that transport distance had significant effects (P < 0.05) on glucose, uric acid, protein, albumin, cholesterol, triglycerides, sodium, potassium, ALT, AST, malondialdehyde, glutathione peroxidase, white blood cell count, heterophil percentage, and heterophil-to-lymphocyte ratio, with linear trends observed for most parameters. However, xylazine administration at both 0.5 and 1 mg/kg BW did not significantly affect any of the measured parameters (P > 0.05), and no significant interaction effects between distance and treatment were observed for most parameters except for potassium (P < 0.05). Regarding interaction effects (distance × treatment), no significant interactions were observed for the majority of parameters (P > 0.05); however, a significant interaction was detected for serum potassium (P < 0.05), indicating that the effect of xylazine on potassium concentration was dependent on transport distance. In conclusion, transport distance significantly alters biochemical, oxidative, and hematological parameters in day-old broiler chicks, indicating a pronounced stress response, but xylazine at the tested doses failed to mitigate these transport-induced changes.