How do I tell when my mare is ready to breed?

Horses August 03, 2011 Print Friendly and PDF

A mare will show signs of heat (sexual acceptance of the stallion) about four to seven days of her approximately 21-day-long cycle. In between the heat periods, she is not receptive to a stallion. To check this, you need to tease her with a stallion, something that stallion owners will do as a daily or every-other-day routine to mares. A mare will urinate, swat, lift her tail, and show behavior consistent with receptivity to the stallion when she is in heat. However, these reactions are variable, so breeding farms will use a veterinarian to palpate the mare's reproductive tract or use an ultrasound machine to view the ovary to better pinpoint the time she releases an egg (occurs the latter part of a heat cycle).

Below are links to more information.

Connect with us

  • Twitter
  • Facebook
  • YouTube
  • Pinterest


This is where you can find research-based information from America's land-grant universities enabled by



This work is supported by the USDA National Institute of Food and Agriculture, New Technologies for Ag Extension project.