Abstract: The effects of lipoic acid (LA) on the antioxidant status of broilers were
investigated. Birds (1 day old) were randomly assigned to four groups and fed
corn-soybean diets supplemented with 0, 100, 200, 300 mg/kg LA, respectively. The
feeding program included a starter diet from 1 to 21 days of age and a grower diet from 22
to 42 days of age. Serum, liver and muscle samples were collected at 42 days of age. For
antioxidant enzymes, superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px)
activity in serum, liver and breast muscle significantly increased in chickens fed with LA.
The concentration of malondiadehyde (MDA), an indicator of lipid peroxidation, was
significantly lower in serum, liver and leg muscle in birds that received LA than in the
control group. Treatments with LA significantly increased glutathione (GSH) content in
liver and increased α-tocopherol content in leg muscle as compared to the control. These
results indicate that dietary supplementation with 300 mg/kg LA may enhance antioxidant
capability and depress oxidative stress in broilers