Paper summary: Body temperature and behaviour of mares during the last two weeks of pregnancy
Statistical analysis of the percentage of time spent in different positions over 2 weeks (in the study: 66.8% standing, 27.0% eating, 4.9% lying sternal, 1.0% lying lateral) and differences on the evening of birth (+5.3% walking, +8% lying sternal, +5.3% lying lateral, -13.5% standing).
Out of 58 births, 54 births (97%) occurred while lying down, and 50 mares (86%) gave birth between 6 PM and 6 AM.
Behavior of mares during the 2 weeks preceding foaling in percentage of time per day (day 0 = day of foaling)
Definition of observed behaviors:
- Lying lateral: the mare is lying on her side with her head and neck extended on the ground.
- Lying sternal: the mare is lying on her belly with her front legs folded.
- Standing: the mare is standing when she is on all four legs; no distinction is made between standing awake or asleep; if she is standing while eating, the behavior is recorded as eating.
- Walking: the mare has moved two or more of her legs within a 3-second period.
- Eating: the mare is eating; chewing wood or other non-food items is not counted as eating, nor is searching for food. (In this experiment, as the mares were observed every 30 minutes, if fecal matter was seen on the ground upon arrival, it was assumed the mare had eaten, and this was recorded as the "Eating" behavior).
The day before birth (day 1), mares spent as much or more time lying lateral, which could indicate a need for rest, as no muscular activity is recorded during their sleep (Ruckebusch study in 1972 on farm animal sleep cycles), while the reduction in time spent lying sternal could suggest an increased need for vigilance as foaling approaches.
Thirty minutes before birth, mares spent an average of 48.7% of the time standing, 10.2% lying sternal, 10.2% lying lateral, 10.2% eating, and 20.5% walking.
In this study, 54/58 births (96%) occurred in a lying position, but researchers emphasize that behavioral changes are minimal (likely an evolutionary adaptation to minimally signal an approaching period of weakness in the mare); less time spent lying sternal is the only significant behavioral change observed in mares until the day of foaling.
Shaw, E. B., Houpt, K. A., & Holmes, D. F. (1988). Body temperature and behaviour of mares during the last two weeks of pregnancy. Equine veterinary journal, 20(3), 199–202. https://doi.org/10.1111/j.2042-3306.1988.tb01499.x
About the author(s)
Article written by Simon Riembault, member of the FirstBreath team