Participating in a cooled, transported semen program places more responsibilty on the mare owner. At the breeding farm, an experienced breeding manager oversees teasing mares, monitoring a mare's estrous cycle, is familiar with various reproductive disorders which may keep a mare from conceiving, and is a skilled technician in either live-cover or artificial insemination. When the mare is kept at home, the owner assumes responsibility as the breeding manager. Owners unfamiliar with the specifics involved in equine reproduction need a veternarian with equine reproduction and artificial insemination expertise. As with any breeding program, success depends on the reproductive health of normal cycling mares. Mares must be inseminated at the correct stage of their estrous cycle.

Preparing and Breeding the Mare

Preparation for a mare to be inseminated with cooled semen is no different than any other mare trying to conceive. The mare must be in good body condition, vaccinated, and on a regular deworming schedule. If mares are to be bred early in the year (February or March), they should be placed under artificial lights starting in November. Most mares will have shed their winter hair coats upon entering the breeding season which begins in late April and continues through August. Typically a mare will cycle every 21 days and be in heart for 5 to 7 days.

The very best indicator of a mare's cyclicity is to have acess to a teasing stallion. Mares should be teased every other day to detect heat. Once a mare begins to show signs of heat, her ovaries and cervix should be palpated and ultrasounded. Producers unable to tease a mare are at a disadvantage and must rely on periodic palpation and ultrasound exams to detect when she is cycling. A mare continually develops follicles on her ovaries throughout her estrous cycle. Thus ovarian activity may be detected, but the mare may be weeks away from actually being in heat. Without access to observing the typical behavioral changes of a mare in heat, it may take several examinations to determine where she is in her cycle. Postpartum mares will have a "foal heat" 7 to 14 days following foaling, and a second cylce approximately 30 days later. Therefore owners of lactating mares should have some indication as to when reproductive exams should be initiated.

It is critical that the mare owner and stud farm routinely communicate to be aware of each other's schedule. Most stud farms collect each stallion on a every-other-day schedule. However, depending on the stallion and farm, this may occur more or less frequent. Furthermore, many popular stallions will have several cooled semen customers, and schduling of shipments with adequate semen may be a problem. The stud farm should be notified the first day the mare comes into heat so any preplanning can be done.

Pregnancy rates from cooled semen are the highest when mares are inseminated within 24 hours following semen collection. Some stallion semen is highly viable up to 48 hours following collection. Semen stored up to 72 hours may appear to have good motility, but fertilization capabilities are poor. Mares will ovulate 24 to 48 hours before the end of heat, so frequent examination of their ovaries is important to predict ovulation, yet not miss it. If a mare has not ovulated following the initial insemination, a second semen shipment may be necessary. Mares should be teased regularly following insemination, and can be ultrasounded for pregnancy 14 days following ovulation. As with any breeding program, mares should continue to be teased through 40 days of pregnancy and ultrasounded a second time to ensure a viable pregnancy. The stud farm should be kept notified of the mare's early pregnancy progress.