Predictive utility of pre-partum temperature changes in the mare.

Area of Science:

• Veterinary Medicine
• Animal Physiology
• Reproductive Biology

Background:

• Rectal temperature monitoring is crucial for assessing mare health and reproductive status.
• Understanding circadian rhythms in equine physiology is essential for accurate health assessments.
• Parturition in mares is often preceded by physiological changes, including temperature fluctuations.

Purpose of the Study:

• To investigate the circadian variation in rectal temperature in mares.
• To determine if rectal temperature changes occur prior to parturition.
• To correlate parturition timing with pre-partum temperature patterns.

Main Methods:

• Rectal temperature was measured in 22 mares at three time points daily for seven days pre-partum and one day post-partum.
• Mares were grouped based on their parturition time: 0700-1500 h, 1500-2300 h, and 2300-0700 h.
• Circadian patterns and pre-partum temperature changes were analyzed in relation to foaling time.

Main Results:

• A clear circadian variation in rectal temperature was observed, with the lowest temperature at 0700 h.
• The typical nocturnal temperature increase was absent on the day prior to parturition (Day -1).
• A statistically significant decrease in rectal temperature preceded parturition in mares foaling between 1500 and 2300 h; a similar trend was noted in other groups but was not significant.
• Post-partum, rectal temperatures initially rose above normal before returning to baseline levels.

Conclusions:

• Circadian rhythms in rectal temperature are present in mares but are disrupted prior to parturition.
• A significant pre-partum temperature decrease may serve as a parturition indicator, particularly for afternoon foaling.
• Post-partum hyperthermia is a normal physiological response in mares.