Impact of exercise frequency, race distance, age, and pregnancy stage on oxidative stress and lipid metabolism in purebred Arabian mares.

Overview

• This study investigated how exercise frequency, race distance, age, and pregnancy stage affect oxidative stress and lipid metabolism in pregnant Purebred Arabian mares.
• The research aimed to understand the impact of different training intensities on the health of pregnant mares by measuring specific oxidative stress markers and lipid metabolites at different pregnancy stages.

Introduction and Background

• Pregnancy naturally raises oxidative stress in mares, which can negatively impact the health of both the mare and her foal.
• The relationship between exercise during pregnancy and oxidative stress has been unclear, creating a need to evaluate how exercise intensity influences oxidative balance and lipid metabolism.
• Oxidative stress involves an imbalance between antioxidants and reactive oxygen species, leading to potential cellular damage.
• Lipid metabolism markers such as cholesterol and triglycerides are important for understanding energy and metabolic status during pregnancy and exercise.

Study Objectives

• To explore how different levels of training affect oxidative stress and lipid metabolism in pregnant Purebred Arabian mares.
• To determine the effects of mare age and pregnancy stage combined with exercise frequency on oxidative and metabolic markers.

Materials and Methods

• Subjects: 22 clinically normal Purebred Arabian mares from Algeria.
• Grouping: Mares were divided into three groups based on age and exercise frequency.
• Exercise groups included mares that differed by race participation and frequency of training.
• Sampling Points: Blood samples were taken during early and mid-pregnancy to assess changes over pregnancy stages.
• Oxidative Stress Markers:
  • FRAP (Ferric Reducing Antioxidant Power) – measures total antioxidant power.
  • TBARS (Thiobarbituric Acid Reactive Substances) – indicates lipid peroxidation, a marker of oxidative damage.
• Lipid Metabolism Markers:
  • Total cholesterol (CHOL)
  • Triglycerides (TG)

Results

• There was a significant increase (P < 0.05) in both FRAP and TBARS levels during the first trimester in the oldest mares that did not participate in racing, indicating higher oxidative stress and antioxidant activity.
• Positive correlations were observed between:
  • FRAP levels and mare age – older mares had higher antioxidant power.
  • TBARS levels and pregnancy stage – oxidative damage markers increased as pregnancy progressed.
• Negative correlation between FRAP levels and racing frequency was found, suggesting that more frequent exercise may reduce antioxidant capacity or oxidative stress levels.

Discussion

• Older mares that were unexercised during pregnancy displayed elevated oxidative stress markers, suggesting increased susceptibility to oxidative imbalance during pregnancy.
• The increase in FRAP in older mares may reflect a compensatory rise in antioxidant defenses in response to oxidative stress.
• The increase of TBARS with pregnancy stage indicates progressive oxidative damage during gestation, potentially affecting mare and foal health.
• The negative correlation between FRAP and race frequency implies that exercise might modify oxidative stress, possibly through enhanced antioxidant mechanisms or adaptations in mares that regularly race.
• These findings highlight the importance of considering age and exercise habits when managing the health of pregnant mares, especially in more advanced age groups.

Conclusions

• Oxidative stress levels in pregnant Purebred Arabian mares vary with age and exercise frequency.
• Older mares without exercise are more prone to oxidative imbalance during pregnancy.
• Moderate exercise or racing frequency appears associated with different oxidative stress markers, potentially offering protective effects.
• These insights may help inform exercise management and health monitoring protocols for pregnant mares to ensure better outcomes for both mares and foals.