When to breed a mare?
Breeding horses is a complex process that requires careful planning, proper health assessments, and expert veterinary care. Whether breeding for performance, conformation, or temperament, ensuring the mare and stallion are in optimal condition is crucial. In equine veterinary medicine, checking a horse for breeding involves multiple steps, including reproductive soundness evaluations, hormone monitoring, and ultrasound examinations.
1. Assessing the Mare’s Reproductive Health
Before breeding a mare, a veterinarian performs a pre-breeding exam to assess her reproductive health. This includes:
Physical Examination
Checking overall body condition—mares should be in good health but not overweight.
Evaluating conformation and signs of past injuries that may impact pregnancy.
Reproductive Examination
Rectal palpation and ultrasound: This helps assess the ovaries, uterus, and cervix to determine if the mare is cycling properly.
Uterine culture and cytology: Tests for infections that could interfere with conception.
Hormone testing: Measuring progesterone and estrogen levels helps track reproductive cycles.
2. Tracking the Estrous Cycle
Mares are seasonal breeders, meaning they cycle primarily during spring and summer when days are longer. The estrous cycle lasts about 21 days, with a 5-7 day estrus (heat) period when the mare is receptive to the stallion.
Ultrasound checks track follicle development and ovulation timing.
Teasing behavior with a stallion can indicate when she is in heat.
Artificial lighting programs can be used to encourage early cycling in breeding programs.
3. Evaluating the Stallion
A stallion must also undergo reproductive evaluations, including:
Semen analysis: To check sperm count, motility, and morphology.
Testicular palpation and ultrasound: To ensure no abnormalities.
Breeding soundness exam: To confirm overall health and reproductive capability.
4. Choosing the Breeding Method
Once the mare is determined to be in heat and ovulating, breeding can occur through:
Natural cover: The stallion breeds the mare directly.
Artificial insemination (AI): Semen is collected and placed into the mare’s uterus.
Embryo transfer: A fertilized embryo is transferred from the donor mare to a surrogate.
5. Pregnancy Detection
About 14-16 days post-ovulation, an ultrasound can detect pregnancy. A follow-up exam at 30-45 days confirms fetal development.
By following these steps, veterinarians help ensure successful and healthy pregnancies in breeding horses.