Paper summary: No-contact microchip measurements of body temperature and behavioural changes prior to foaling

Study focused on observing body temperature changes in mares to predict foaling, as well as observing specific behaviors linked to temperature changes.

Observations were conducted over two foaling periods: 2018 and 2019 (March 30, 2018–May 5, 2018, and April 1, 2019–May 2, 2019). 39 Anglo-Arab mares were observed (19 in 2018 and 20 in 2019). 13 mares were primiparous (foaling for the first time), and 26 were multiparous (had foaled previously). No mare was observed in both 2018 and 2019.

The mares were housed in 16m² stalls and had access to pasture three days a week from 10 AM to 4 PM in groups. They were fed twice daily at 8 AM and 4 PM with forage and a dietary supplement composed of barley, soybean meal, and minerals; water was available ad libitum.

Specific behaviors:

- Flehmen: curling of the upper lip to detect odors.

- Nesting: preparing a comfortable area to lie down by circling or pawing the ground.

- Looking at the flank.

- Scratching the hindquarters against the stall wall.

In 2019, video recordings from surveillance cameras were collected to analyze behavior during the hour before foal expulsion in 8 multiparous mares. The frequency and duration of lying lateral (lateral recumbency) and the frequency and duration of specific behaviors (flehmen, nesting, looking at the flank, scratching hindquarters against the stall wall) were recorded.

The average gestation period was 323 ± 6 days. All foals were born normally without human assistance. 36/39 (~92%) foals were born at night (7 PM–7 AM); the other three were born at 7:40 AM, 12:17 PM, and 5:10 PM, respectively. Two foals died within six months after birth: one became ill 10 days after birth, and the other suffered a leg fracture. In both cases, these events were unrelated to the birth.

"These observations are consistent with previous behavioural studies demonstrating increased restlessness with pre-parturient mares repeatedly alternating lying down and standing bouts [11], increased time spent lying down [11,12] and walking time [50]. These increases have been shown to be very variable between mares but they could possibly be reliable for detection of impending parturition (from 2 h before foaling)."

According to this study, the simple frequency and duration of "lateral recumbency" and "walking" could be a reliable source to help predict foaling 2 hours in advance.

Auclair-Ronzaud, J., Jousset, T., Dubois, C., Wimel, L., Jaffrézic, F., & Chavatte-Palmer, P. (2020). No-contact microchip measurements of body temperature and behavioural changes prior to foaling. Theriogenology, 157, 399–406.https://doi.org/10.1016/j.theriogenology.2020.08.004