Abstract
The aim of the study was to determine the effect of the perinatal period on redox status indicators in the blood of ewes before and after lambing and during lactation. The study was performed on 12 ewes of the synthetic SCP line. Blood for testing of redox parameters was collected seven times: before pregnancy, 1.5 months and 24 h before lambing, 2 and 24 h after lambing, and in the fourth and eighth weeks of lactation. The following blood indices were determined by spectrophotometry: lipid peroxides, malondialdehyde, superoxide dismutase, catalase, plasma total antioxidant capacity, uric acid, urea, bilirubin, and creatinine. The tests showed that during the perinatal period reactions are generated which lead to oxidative stress. Oxidative stress in pregnant ewes was found to increase during the period before lambing and may persist even up to weeks 4-8 of lactation.