Evaluating Oxidative Stress, Nitric Oxide Production and Mitochondrial Activity Trend in Broiler Blood Cells under Progressive Cold Stress

Broiler production is crucial for global food security as a high-quality protein source. However, climate change causes extreme temperature fluctuations, including severe cold stress. Sudden ambient temperature drops impair broiler growth and health. This study investigates how continuously decreasing ambient temperature affects oxidative stress and mitochondrial activity in broiler blood cells.

Blood cells pooled from two broiler chickens were diluted and subjected to a gradual temperature reduction from 42°C to 0°C, with 3°C decrements at each step. Mitochondrial activity, malondialdehyde (MDA), total antioxidant capacity (TAC), hydrogen peroxide (H₂O₂), reduced glutathione (GSH), catalase activity and nitric oxide (NO) levels were subsequently measured.

Mitochondrial activity and NO levels showed significant quadratic trends (P<0.05), increasing at moderate cold before declining at lower temperatures. From 42°C to 21°C, mitochondrial activity rose significantly at 39–33°C and 21°C (P<0.05), while MDA levels increased at 39–27°C and 21 °C (P<0.05). TAC declined significantly from 42°C to colder points (P<0.05). Between 18°C and 0°C, mitochondrial activity and NO fluctuated, suggesting an adaptive response. Conversely, H₂O₂, GSH and catalase levels remained stable across all temperatures (P>0.05). These findings highlight a complex cellular response to cold stress, emphasizing the need for proper cold stress management in broiler production.