Estrus, or heat, is behavior that occurs during the ovulation period of the mare which usually ends within 24 to 48 hours of ovulation.
Estrus is the time when the mare is receptive and will accept the stallion. Estrus lasts an average of 5 to 7 days.

Signs of estrus include:
- Frequent Urination
- Squatting Posture
- Clitoral “winking"
See Horse Breeding Behavior for more information.
