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

Background: 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. Methods: Blood cells pooled from two broiler chickens were diluted and subjected to a gradual temperature reduction from 42oC to 0oC, with 3oC 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. Result: Mitochondrial activity and NO levels showed significant quadratic trends (P less than 0.05), increasing at moderate cold before declining at lower temperatures. From 42oC to 21oC, mitochondrial activity rose significantly at 39-33oC and 21oC (P less than 0.05), while MDA levels increased at 39-27oC and 21oC (P less than 0.05). TAC declined significantly from 42oC to colder points (P less than 0.05). Between 18oC and 0oC, mitochondrial activity and NO fluctuated, suggesting an adaptive response. Conversely, H2O2, GSH and catalase levels remained stable across all temperatures (P greater than 0.05). These findings highlight a complex cellular response to cold stress, emphasizing the need for proper cold stress management in broiler production.