Horse Reproduction Information

Successfully breeding horses requires an understanding of the reproduction process. It is the responsibility of the owners of the mare and stallion to ensure the horses are healthy and free from disease before considering breeding. Also, providing the horses with the proper nutrition, which includes a diet rich in protein, is an important factor for a healthy foal.

  1. Breeding Season

    • Horses have a breeding season when they become fertile for breeding. This season usually begins around February or March and ends sometime around October. A mare usually starts her reproductive cycle around the age of 3 and continues into her early 20’s.

    Heat Cycle

    • The heat cycle for a mare generally lasts 21 days. One egg is released during the cycle and it occurs at the end of the heat cycle, approximately 24 hours before the end of the heat cycle. The mare is in “standing heat” for about five days near the end of the heat cycle when she raises her tail and is receptive to the stallion.

    Breeding

    • When the mare is willing to accept the stallion’s advances and “showing” heat, breeding is recommended every other day for hand breeding and artificial insemination. Since the stallion’s semen is vital for up to three days, it is not necessary to have the stud cover the mare every day unless she has proven to be a difficult breeder.

      A high-protein diet should be fed to both the stallion and mare before and during breeding. The stallion needs extra protein to produce healthy semen and the mare needs to be in excellent condition for her body to prepare for the next 11 months.

    Gestation

    • The gestation period for a horse is between 335 to 340 days, but can be up to 370 days according to the University of Nebraska Lincoln. A foal born before 326 days of gestation is considered premature. Variables, such as the mare’s condition, the time of year and sex of the foal, have shown to influence the gestation time.

    Foaling

    • A mare generally delivers a foal with no assistance needed. Since they tend to deliver in the late night or early morning hours, catching the foaling may be difficult. Also, unlike most animals, a mare actually has the ability to delay foaling if she feels threatened, making it even more difficult.