What is the geststion period for a horse?

"Gestation" means length of pregnancy, or rather how long a female horse, being a mare, carries a foal, from conception (mating with stallion) to birth.

Gestation for a horse is typically 310 days, which is generally considered the lowest number of days to produce a viable foal, without special care/veterinary treatment. However a mare can be pregnant up to 370 days...with 340-345 days the norm.