Does age and parity affect the oxidative profile of pregnant and postpartum mares?
Authors: Rosa Filho R R, França D S, Alonso M A, Riccio A V, Affonso F J, Brito M M, Francischini M C P, Nichi M, Boakari Y, Fernandes C B
Journal: Journal of equine veterinary science
Summary
# Editorial Summary Pregnancy demands substantial metabolic resources in mares, particularly during the final trimester when oxygen consumption rises sharply and reactive oxygen species production accelerates—a phenomenon well-characterised in humans but understudied in equines. Researchers measured oxidative and antioxidant markers in 17 mares across three age groups (3–7, 8–11, and ≥12 years) and varying parity levels, sampling during late gestation, peripartum, and postpartum periods using TBARS analysis, enzymatic antioxidant assays (glutathione peroxidase, glutathione reductase, superoxide dismutase), and mineral quantification. Maternal age emerged as a significant factor: older mares demonstrated elevated glutathione peroxidase activity with consistent time-dependent changes, whilst magnesium concentrations showed a notable interaction with both age and gestational stage—findings suggesting adaptive antioxidant responses rather than oxidative stress per se. Lipid and protein oxidation markers, iron levels, and other enzymatic defences remained stable across age groups and reproductive stages, indicating pregnant and postpartum mares maintain robust oxidative balance regardless of age. For practitioners managing geriatric broodmares or monitoring high-parity animals, these findings suggest age-related adjustments in antioxidant capacity may be physiologically protective rather than pathological, though magnesium status warrants closer attention during late gestation and transition to lactation.
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Practical Takeaways
- •Monitor antioxidant status and magnesium levels more closely in older pregnant mares (≥12 years), as age-related changes in glutathione peroxidase activity may affect their physiological reserves during late gestation and parturition
- •Parity appears less important than age in determining oxidative stress responses during pregnancy and postpartum, suggesting breeding programmes should account for maternal age over number of previous pregnancies
- •Nutritional supplementation or monitoring of magnesium and antioxidant capacity may warrant consideration in geriatric pregnant mares to support optimal maternal and fetal outcomes
Key Findings
- •Maternal age influences glutathione peroxidase levels during late gestation, parturition, and postpartum phases, with older mares showing higher levels
- •Age and gestational duration interact significantly to affect magnesium concentrations in pregnant and postpartum mares
- •Glutathione reductase, superoxide dismutase, lipid oxidation, protein oxidation, and total iron showed no significant variations across age groups or parity status during the study period
- •Parity did not significantly affect the oxidative profile of mares during late gestation and postpartum period