Antioxidant capacity and meat quality of broilers exposed to different ambient humidity and ammonia concentrations

To investigate the effect of humidity and ammonia on the antioxidative capacities and meat qualities of broilers, 192 broilers were divided into 2 groups: high (H, 70 ppm) and low (L, 30 ppm) ammonia concentration. These groups were divided into 30% (Treatment humidity, T) and 60% (Control humidity, C) humidity, giving 4 treatments: C+L, C+H, T+L, and T+H. Blood and muscle antioxidative capacities and meat quality were measured. In the H group, body weight (BW), average daily feed intake (ADFI), average daily weight gain (ADG), blood and muscle antioxidative capacities, and postmortem pectoral muscle a* of broilers were significantly decreased (P < 0.05), and pectoral muscle thiobarbituric acid reactive substance (TBARS) contents and drip losses, postmortem pectoral muscle b* (P < 0.05) and L* (P = 0.054), and pectoral muscle shear forces (P = 0.075) increased. In the T condition, BW, ADFI, pectoral muscle superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities, and pectoral muscle L* decreased (P = 0.053), and pectoral muscle shear forces and TBARS contents increased (P < 0.05). In the T+H group, BW, ADFI, ADG, blood antioxidative capacities, pectoral muscle SOD and GSH-Px activities, and postmortem pectoral muscle a* were significantly lower than those of the C+L group, but postmortem pectoral muscle TBARS contents and pectoral muscle drip losses and shear forces significantly increased (P < 0.05). These results revealed that T+H could significantly reduce growth performance, antioxidative capacities, and meat quality of broilers; T intensified these negative effects.