Early and accurate diagnosis of pregnancy in the mare is critical in determining her reproductive viability during the breeding season. Once a mare has been determined to be pregnant, her embryonic growth and fetal development may be accurately monit …

The gestation period of the mare is less well-defined as compared to many other mammals. In other words, the window for parturition in the mare is much broader than that of other mammals. Mares are seasonally polyestrus, which means that their breedi …

As discussed several times in this space, mares seasonally polyestrus, which means that their estrous cycles depend on the season. A mare will undergo regular estrus cycles during late Spring, Summer and early Fall, and none during Winter. It is larg …

Many mares posses the bona fides that warrant breeding, such as good temperament, conformation, bloodlines and talent, but age is also a very important consideration. Despite the fact that it isn’t at all uncommon to find mares bred during their 20s, …

How long is a horse pregnant? Well, the short answer is 10 to 12 months, or from approximately 326 days to 354 days (although there have been cases where gestation for a mare has gone as long as 365 to 370 days). Most mares only carry one foal per pr …

Estradiol Cypionate is a pro-drug ester of Estradiol, a naturally occurring hormone that circulates endogenously within the human body. Estradiol is the most potent form of all mammalian estrogenic steroids and acts as the major female sex hormone. A …

Estradiol is a medication and naturally-occurring steroid hormone. It is an estrogen and is used mainly in hormone therapy. Estradiol cypionate (ECP) is used to induce estrus in horses. It is also used by veterinarians to treat estrogen-responsive in …

A working knowledge of the mare’s reproductive anatomy and physiology is essential in a horse breeding program. Familiarity with the mare's estrous cycle and the timing of events therein is equally important. These provide the basis on which all …

Generally speaking, the best time for mating of a mare and stallion is determined by several factors. These include the length of daylight (season), the daily temperature, the mare's general health, diet, the amount of rainfall, the climate, and …

Mares are seasonally polyestrus; this means that they experience regular estrus cycles during late Spring, Summer and early Fall, with none occurring during the Winter. The typical mare cycles regularly between March and October, with each estrou …

During the fetal development of the mare itself, a pool of primordial follicles forms as ovarian tissue, and each follicle consists of prophase I oocytes surrounded with a single layer of flattened granulosa cells.1 By the time the mare reaches s …