Effects of H2O2-induced oxidative stress on the level of ROS in thigh muscle of broilers on 42 days post-hatch. Control is the noninjected treatment. Saline is 1 mL/kg BW physiological saline (0.75%) injected treatment. 2.5%H2O2, 5%H2O2 and 10%H2O2 are H2O2 treatments injected with 0.74, 1.48, and 2.96 mmol/kg BW H2O2 solution per bird; all data were represented as the mean value ± SE of eight sample birds per treatment; a,b,c,d means within a row with no common superscripts differ significantly (P < 0.05).