Mating of mares.

The end of winter and the beginning of spring mark the beginning of an important time in a horse's life: the start of the breeding season and the mating of mares. This is the time of year when pheromones are flying and everyone is in the mood for love. Horses of both sexes are affected by changes in their hormone levels, which signal to them that it's time to mate.

Before deciding to breed mares and breed them, it's important to understand why you're breeding , what you're trying to produce, and what your plan is for the foal. Producing and breeding a foal is a multi-year commitment, so it's worth imagining how the future will unfold.

Once that's clear, when is the best time to cover a mare? The answer depends on several factors, including the mare owner's goals (e.g., an "early" foal for competition or sales), the mare's reproductive status (freshly foaled, first-time, elderly, or problematic), stallion availability and fertility, the mare's facilities, and its geographic location (cold climates or milder climates).

Equine pregnancies last around 11 months, so the decision on the foaling date will determine when to breed the mare.

Most mares have a seasonal reproductive cycle , coming into heat (estrus) for the first time in the season in late winter, early spring, and ending in the fall.

Mares come into heat every 21 days during this breeding season and are fertile and receptive to mating for 5 to 7 days of their cycles. They show a lack of heat from approximately November until late February or March. Even if they show signs of heat, they may not be ovulating, and if mated, they usually do not conceive.

This is nature's way of preventing the arrival of a foal in the middle of winter, when temperatures are low and food is scarce. If we cover the mare in early spring, the future foal will be raised in a temperate climate and grow substantially before winter returns.

A mare generally enters her first heat around 12 to 15 months of age. However, we personally believe it is not advisable to breed mares before they are four or five years old, when they are already physically developed and mentally mature enough to be a good mother. Bred a mare earlier can cause her growth to be stunted due to the physical demands of pregnancy and/or cause her not to be mature enough to properly breed and bond with her foal.

Generally, mares are past their reproductive prime by the time they reach 15 or 16 years of age, but they can carry and give birth to healthy foals well into their 20s, especially if they've had multiple successful pregnancies beforehand. However, she's the type of mare all breeders love to have: well-built and attractive, with great movement, excellent manners, the uncanny ability to consistently produce stunning foals, and she's also a great mother. The problem is that she's starting to age, and her fertility isn't what it used to be.

Horses mate, like many other mammals, through courtship, followed by a stallion mating with a receptive mare. Mares will show signs of being in heat during their most fertile days, which are the five to seven days at the beginning of their cycle. This is the ideal time for horses to mate and produce a foal.

Like most male mammals, males are willing and ready to mate year-round. This means the timing really depends on the female.

When a mare is fertile and in heat, she will show physical signs such as discharge and swelling of the vulva. When a stallion is nearby, she may urinate in front of him (releasing pheromones that signal she is ready to mate) and may straddle him. When she has the stallion's attention, she will raise her tail to show him she is ready.

Although fertile mares are usually receptive to a stallion's attentions, that doesn't mean the stallion doesn't have to make any effort. Stallions will sense a fertile mare through the signals she gives them. To test whether a mare is receptive or not, a stallion may sniff mares or even nudge them to test their readiness.

Once a stallion has discovered a receptive mare, he will elicit the Flehmen response; he will throw his head back, nose in the air, and purse his upper lip. He may prance and show off to the mare, whinny, and often perform a sort of dance, lifting his hooves off the ground. A stallion with a high libido will exhibit enthusiasm for mounting and attempting to sire a mare.

After this display, he will approach her and may bite or pet her. If the mare doesn't reprimand him, he will begin sniffing her rear, legs, and tail. At this point, the mare will likely have raised her tail toward him, and he will mount her. The courtship act is usually a longer display than the mating act itself, which lasts only a couple of minutes.

After mating, the stallion will usually rest on the mare's back for a few seconds and then dismount as the mare walks away. The pair will graze within sight of each other and periodically repeat the courtship and mating while the mare remains in heat.

At the end of heat matings it is not always easy to know if a mare is pregnant , even if she is an experienced broodmare.

Some owners try for years to impregnate their mares, and others are accidentally impregnated overnight by a neighbor's escaped stallion.

One way to check this is to return her to a stallion two weeks after mating her to observe her behavior. If she is receptive to the stallion, then she is most likely not pregnant. Although refusal to be mated is not a guaranteed reason for pregnancy, most mares will reject a stallion's attempts if they have conceived.

To effectively confirm pregnancy , an ultrasound is recommended for the mare 14-16 days after ovulation and mating. A second examination between days 30 and 40 provides an opportunity to assess fetal viability and development.

Horse embryos are no more fragile than those of other species; it's primarily because horses generally have poor reproductive performance (the ability to sustain a conception).

There are many causes of early embryonic loss. Stress, fever, uterine infections, hormonal abnormalities, and twins can all cause a mare to spontaneously abort, and she will usually begin showing signs of estrus to begin the next heat cycle.

In addition to the fertility of the mare and stallion, other factors, such as reproductive management and nutrition, play an important role in conception rates in horse breeding. Reproductive success requires more than luck: it requires the preparation of both stallion and mare, careful maintenance and management, and technical skill to ensure the mare has the best chance of conceiving.

Once pregnancy is confirmed, the mare should live with other horses during her pregnancy, as long as her field companions are not unpleasant. Horses are herd animals and need a social life to be healthy and psychologically balanced. Grazing also provides all the necessary exercise and a regular diet that keeps the mare in proper body condition during pregnancy.

In principle, there is no need to supplement a pregnant mare's diet until the last trimester of pregnancy . Obese mares will have more difficulty foaling within eleven months.