Annatto concentrate reduces oxidative stress in ewes during metabolic challenge stages

This study evaluated the effects of annatto concentrate (ANC) supplementation on oxidative stress markers in ewes during critical reproductive phases: prepartum, postpartum, and weaning. Thirty Dorper crossbred ewes were divided into three groups (n = 10): Control (0 % ANC), 0.5 % ANC, and 1 % ANC. Blood samples were collected at three stages: last third of gestation (100 days), postpartum, and weaning, and analyzed for TAC, MDA, reduced thiols (-SH), hydrogen peroxide (H₂O₂), and the enzymatic activities of catalase, superoxide dismutase (SOD), and glutathione peroxidase (GPx). Results indicated that the 1 % ANC dose significantly reduced H₂O₂ and MDA levels during prepartum period (P < 0.05), while the 0.5 % dose enhanced catalase activity during postpartum (P < 0.01). At weaning, the 0.5 % ANC dose also improved oxidative status by increasing SOD and GPx activity (P < 0.05). These findings suggest that ANC supplementation improves oxidative balance in ewes during metabolically demanding periods, offering a natural strategy to enhance animal health and welfare.