Around day 20, the follicle reaches its full size and ruptures, releasing the egg into the fallopian tube (ovulation). ... The ruptured follicle forms the corpus luteum (CL), which secretes the hormones that prepare the uterus for pregnancy.

How long does a mare ovulate for?

Reproductive Life of the Mare

Mares have two follicular waves each cycle. Although the mare continues to ovulate regularly every 21 days throughout the breeding season, the length of estrus varies, ranging from two to eight days, and the length of diestrus varies accordingly to maintain a 21-day interval.

How long after ovulation can mare get pregnant?

The equine ovum seems to be capable of being fertilized for at least 18 hours after ovulation.