Determination of the activity and relative abundance of mRNA for antioxidant enzymes in stallion testicular and epididymal tissues: A comparison between two breeding seasons.

•SOD activity is higher in the reproductive tract during the breeding season.•SOD1 is the predominant isoform in reproductive tract tissues.•Testicular tissue exhibited low CAT values in both seasons and high GPx activity.•GPx5 expression was highest in the caput epididymis during both seasons.•The reproductive system of stallions adapts well to environmental changes.