No-contact microchip measurements of body temperature and behavioural changes prior to foaling.

This research investigates the use of microchip measurements of body temperature and behaviour changes as indicators to predict foaling in horses. The study finds that a significant drop in body temperature, increased tail movements, and specific behaviours correlate with impending parturition, which suggests that continuous temperature monitoring may aid prediction of foaling time.

Study Design and Participants

• The study encompassed thirty-nine mares observed over two foaling seasons (2018 and 2019).
• The horses were kept in 16 m stalls, with outdoor access in groups three times a week from 10:00 to 16:00.
• Additionally, night watch and video surveillance were employed during foaling periods.

Methods of Monitoring

• Each mare was implanted with a microchip sensor in the neckline for body temperature monitoring. Measurements were manually taken every 2 hours from 5 days before to 6 hours after parturition.
• The mares also wore a tail accelerometer which recorded tail movements and lateral recumbency, beginning 24 hours before the birth.
• In a smaller sampling of eight mares, video analysis was used in the hour preceding the expulsion of the foal to monitor behaviour.
• Behavioural and temperature data correlations were examined using principal component analysis (PCA).

Results and Findings

• All foals were born healthy without the need for human intervention during foal births.
• A significant drop of 0.3℃ was observed in the mares’ average daily body temperature between the day of parturition compared to the average temperature of the 5 days before.
• A significant temperature decrease was also detected 12 hours before and at the start of parturition.
• Utilizing a 0.5℃ threshold, parturition could be anticipated 12 hours in advance with 96.6% sensitivity and 95.0% specificity.
• The study revealed more frequent and shorter tail movements as foaling approached.
• Increased frequency and duration of specific behaviours (such as flehmen, looking at their flank, and rump scratching against the stall wall) were observed, positively correlating with body temperature.

Conclusion

• Just as in other species, body temperature changes in mares are connected to signals usually associated with impending parturition, wherein a significant temperature decrease starts to be seen 12 hours prior to and during foaling.
• This suggests that should automated temperature monitoring technology be developed, it could be employed as an additional tool to predict parturition in mares.