Photo/Illutration A herd of mares in foal gallop along a snow-covered track with their swollen bellies swinging in Otofuke, Hokkaido, on Jan. 16. (Kengo Hiyoshi)

OTOFUKE, Hokkaido--A herd of mares in foal galloped across a snow-covered track here on Jan. 16 for wintertime exercise to improve their health and prepare for a safer, easier delivery.

Guided by a farm employee on horseback, the horses covered a couple of laps on the 800-meter track.

The 86 horses, 52 of them pregnant and weighing a ton, belong to a research stock farm run by the National Livestock Breeding Center.

The pregnant horses are given opportunities for regular exercise, particularly in the winter when they tend to become inactive.

The horses’ exercise sessions are open to the public on weekday mornings until Feb. 24. They will continue doing the workout, with or without an audience, until April.

The mares are expected to give birth between the middle of February and the end of April.