Physiological and Antioxidative Effects of Dietary Acetyl Salicylic Acid in Laying Japanese Quail (Coturnix japonica) under High Ambient Temperature

The objective of the present study was to determine if acetylsalicylic acid (ASA) would have further antioxidative effects beyond lowering rectal temperature of stressed laying Japanese quail and hence improve its physiological status. During summer season when daily high temperatures averaged between 33 and 36°C and relative humidity averaged between 60 to 70%, four treatment groups of adult Japanese quail each containing three replicates of fifteen females were fed either a control diet containing 0% ASA or the control diet supplemented with 0.025, 0.05 or 0.1% ASA from 8 to 16 wk of age. Rectal body temperature was significantly decreased by feeding 0.05 and 0.1% ASA. Hen-day egg production was significantly increased for quails fed the diet containing 0.05% and 0.1% ASA. Shell thickness seemed to be thicker at the higher levels of ASA. Serum T3 concentration was decreased significantly (P≤0.05) in quails fed 0.1% ASA (0.38ng/ml) in comparison with controls (0.62ng/ml), but serum T4 concentration was not significantly affected. Dietary ASA had a positive effect on humoral immunity and quails fed 0.05 and 0.1% ASA had a significantly higher total antibody titer compared to other treatments. ASA treatments caused a significant decrease in serum cholesterol, glucose and hepatic TBARS as an indicator for lipid peroxidation, as well as enhancement in the activity of antioxidative enzymes GSH-Px and SOD in a dose dependent manner. These antioxidative effects were accompanied with a significant reduction in corticosterone levels due to ASA treatments. Therefore, it could be concluded that feeding diets containing 0.05 or 0.1% ASA during the summer season could have potential benefits for poultry welfare and productivity because of reducing body temperature and oxidative stress, which consequently allowing more physiological resources to be used for responding to environmental stressors.