Evaluation of the oxidative status of periparturient mares supplemented with high amount of α-tocopherol

Abstract

Aim of the study was to investigate the oxidative status during peripartum period in mares fed high amount of dietary α-tocopherol. α-Tocopherol, ferric reducing ability of plasma (FRAP) and reactive oxygen metabolites (d-ROMs) levels were measured in blood samples from 17 Thoroughbred mares at three intervals: (1) 20 days before the expected foaling date; (2) 12 h following parturition; (3) 7 days post-partum. The levels of α-tocopherol, d-ROMs and FRAP were retrospectively analysed in relation to the number of insemination services (Ins) after foaling performed per conception. The parameters α-tocopherol and d-ROMs evidenced minimal fluctuations during peripartum period while FRAP levels showed a linear decrease. The α-tocopherol did not show significant variations and was numerically higher in mares >10 years old while FRAP levels were significantly higher in older mares in the post-partum. Mares receiving three natural insemination services showed higher levels of FRAP in the pre-partum period (p = .009) and lower values of α-tocopherol (p = .015) in the postpartum compared to mares receiving one service. No d-ROMs level differences appeared among service classes. Oxidative stress is not present in periparturient mares fed 2.750 IU of supplementary α-tocopherol. Differences in redox metabolism are detectable between young and old mares. Plasma antioxidant potential is higher in older mares particularly in the post-partum period.Highlights Oxidative stress is not present in periparturient mares fed 2.750 IU of supplementary α-tocopherol. Antioxidant potential of plasma is higher in mares older than 10 years compared to younger mares. The increased plasma antioxidant potential seems related to an increase in services per conception.

Keywords

• periparturient mare
• oxidative stress
• α-tocopherol
• frap
• d-roms