How do horses mate?
Like every animal, horses have a mating season every year so that they can participate in natural selection and the continued survival of their species.
In this article, I will explain everything about horse mating behavior and the breeding season to educate equestrians, especially those who want to have their own foal in the future.
How Do Horses Mate?
Like most species with mating seasons, horses exhibit specific mating patterns and behavior. So how do horses breed? Horse mating patterns typically involve a courtship between a mare and a stallion.
Mating is necessary to preserve the horse population. Mares and stallions can mate after reaching sexual maturity at the ages of three or four.
Mares can get pregnant and breed with stallions as early as age 2, but this is not recommended because the sexual organs have not fully developed. Also at age 2, the filly is still growing herself, which can cause problems with foaling and they also might not be mentally mature enough to raise a foal.
The three stages of horse mating (1) behavior are a courtship, mating, and postmating behavior.
Courtship is present in the natural mating of wild horses and the mating behavior of domesticated horses, provided they are allowed to breed naturally.
When there is in-hand breeding or forced breeding with human intervention, horses skip the courtship stage and move straight to mating.
In courtship, the highest-ranking stallion in a herd of wild horses or the stallion of choice in domesticated breeding will groom, nuzzle, sniff, and prance around the mare.
The dominant horse is examing the mare’s entire body. This behavior is an attempt to woo the mare, and allow the mare to demonstrate her acceptance of the stallion before mating.
The mare will either kick and bite to tell the stallion she is not ready, or stand still, lift her tail, and urinate. This invites the stallion to mount her, initiating the mating phase of the breeding process.
A mare and stallion pair will often separate from the rest of the herd during mating.
READ MORE: What is a Group of Wild Horses Called?
How Long Do Horses Mate For?
The entire mating process can take anywhere from hours to days depending on the closeness and sexual attraction between the stallion and mare pair.
The mounting process between stallion and mare usually takes less than one minute, and a wild stallion can mate with 2 mares within 7 minutes.
The mating behavior varies greatly between stallions and mares, so these numbers can change. Each pair takes things at their own pace.
Horses mate usually only in the spring and summer both in domesticated breeding and in the wild. Mares rely on the long days during this time of year to initiate their estrus cycle.
However, some breeds like Arabians, Thoroughbreds, and the American Quarter Horse are made to breed in the late winter months and early spring in the hopes of producing more mature horses.
To do this mares are put under lights so they come into season earlier.
Horses that are more mature and have better development perform better in races and shows. This is key in the horse racing industry when horses are being raced at 3 years old.
When stallions mount the mare, it is usually from the back as their reproductive organs are found behind their tail.
To mount, the stallion wraps their front legs around the barrel of the mare and holds on, resting their head against the mare’s back. The stallion usually dismounts the mare within 15 seconds of initiating the mating behavior
The two horses engaged in mating will typically whinny, nicker, squeal and grunt with varying intensities and durations.
Postmating Behavior Stage
Postmating (3) behavior is the behavior after the mating process is complete, which may include attempts by the stallion to re-mount the mare.
These repeated mounting attempts can damage the relationship between the mare and the stallion.
Horses may also fall over after completing mating behavior, and I will discuss the reasons why later.
CHECK: Horse Genders Explained
When is Horse Breeding Season?
Horses are seasonal breeders, meaning they breed at specific times during the year. The natural breeding season for horses is from early spring into late summer.
The reason why horses are seasonal breeders is that their gestation period is 11 months long and the warm climate of the spring and summer are the best to raise foals in.
Also, the lack of sun in the winter months prevents mares from going into heat. Essentially during this time, their reproductive cycling shuts down.
Mares have their estrous cycle during the breeding season, so they have to take advantage of the spring and summer.
How Often Does a Horse Come in Heat?
Mares come into heat every 21 days. A mare’s estrous cycle or heat cycle typically lasts for 7 days but can be anywhere from 4 to 10 days long. Heat length is different from mare to mare.
The first heat cycle of the season is usually irregular, but then the rest of them proceed as normal.
During the estrous cycle, the mare ovulates in the hopes that one of her eggs will be fertilized through mating with a stallion.
While in heat, mares urinate frequently and change their behavior to become receptive to the stallion.
They will squeal and whinny often to try to get a stallion’s attention and gain his advances. Mares may also lift their tail towards a stallion to reveal their reproductive organs.
Some mares are very obvious and will display these behaviors to geldings as well! I have one of these mares myself!
This teases the stallion and invites them to begin the courtship process. While they are in heat, mares can also be more irritable and resistant to work under the saddle and the ground.
I have been around a mare in heat before and it is a sight to see.
My friend was bringing her mare back from the pasture to be groomed and she urinated right in front of us and was uncomfortable.
Both of us were surprised at first but had a good laugh about it afterward.
The gestation (4) period for a pregnant mare averages anywhere from 330 to 342 days. However, mares can carry their foal over this period. My own mare foals at 345 days.
Mares have some control over when they actually foal. They can hold out for better weather. It’s pretty amazing!
About 6 to 9 days after foaling, mares exhibit a behavior called foal heat. Foal heat is the first estrus cycle that a mare has after having a foal. This can take place anywhere from 5 to 15 days after foaling.
Why Do Horses Fall After Mating?
After mating is complete, it is common for the mare and stallion to fall over. Why do horses fall over after mating? There are three main reasons for this
- It is their first time mating- the stress of the first mating experience and the aggression of the stallion in mating causes the pair to fall over
- Hormone Imbalances-if the hormones of the mare and stallion are imbalanced, this leads to changes in behavior which cause both of them to fall after mating
- Stress– if the mare and stallion are chronically stressed due to the conditions they mate in, the pair can fall over. Make sure they have plenty of space to mate to avoid this.
- Syncope– both mare and stallion can have syncope, which results from insufficient blood flow to the brain. Because of the lack of blood reaching the brain, horses with syncope faint and can do so after mating.
Horses falling over after breeding is a situation that no horse owner or breeder wants to face. Knowing what causes this can help you prevent it and ensure your horses have a smooth reproductive cycle.
READ MORE: Do Horses Need a Companion?
Wild vs Domesticated Horse Breeding Behavior
The mating behaviors (2) of a feral herd and domesticated horses have some significant differences.
Especially since one occurs by natural instinct and the other occurs in a controlled environment both with and without human interference.
Domestic breeding practices are considered selective breeding because the pairings are chosen by horse owners.
Wild Horse Mating Behavior
Semi-wild and feral horses breed in the late spring and midsummer in a group of one stallion and several mares.
The dominant stallion displays two major reproductive behaviors, harem formation, and courtship and mating.
Harem formation is all the things the stallion does to keep his herd together. While the herd is grazing, the stallion will circle them, and he will be in the back to herd them on while they are on the move.
This behavior helps protect the herd from threats. Stallions also mark their territory and exhibit the flehmen response when surveying it.
Although all horses use the flehmen response, it is more common in stallions and geldings than mares. The flehmen response helps horses investigate smells.
Young colts who are not the dominant males can form a bachelor herd to find their own mares to mate with.
Courtship and Mating
In the wild, feral horses initiate their own mating behavior. The dominant horse will prance up to their mare of choice with an arched neck and raised tail.
The prancing is usually accompanied by stomping, whinnying, and snorting. In the days before the mare’s estrus cycle, the stallion will nip at her and kick or strike.
If the mare continues to display threatening and nonreceptive behavior like kicking, squealing and pinning the ears the stallion will leave her alone.
Even when the mare is in heat, the initial behavior will be aggressive. Mares in heat will display courtship behavior such as lifting the tail and presenting the reproductive organs to the stallion, urinating frequently.
After the courtship, if the mare accepts the bachelor stallion, the stallion will mount her and begin the mating process. The stallion dismounts the mare after 15 seconds and may sniff or urinate over any of the secretions given off in mating.
The entire mating process usually takes place in a minute or less, and feral stallions can mate with the same mare multiple times with a few minutes pause in between,
The mating behavior of feral stallions is highly organized based on a dominance hierarchy. Stallions compete to mate, and only the alpha stallion gets to breed to the mares.
Here is a video showing natural horse breeding behavior.
Domestic Horse Breeding Behavior
How do horses mate in a domestic environment? In a domestic environment, the social behavior horses exhibit before mating is hindered.
There is selective breeding, where the mare owner decides what stallion to pair with her. An owner may have only a couple or many mares in their breeding stock. Most breeders focus on just one breed of horse.
On breeding farms and other stables, the stallions are usually kept separate from the mares and geldings so that they do not engage in sexual behavior prior to the scheduled breeding date.
Interaction with mares is limited to breeding. Mating is allowed by three different methods on domestic breeding farms:
- Natural cover pasture breeding– the stallion and two or more mares are placed in a pasture to engage in courtship and mating on their own terms
- Natural cover in hand- the stallion is presented to the mare while haltered by the handler on one or more days when the mare is in heat
- Artificial insemination– a collection of semen from the stallion followed by intrauterine infusion of semen into the broodmares of choice.
For the in-hand cover, the stallion will likely be muzzled to prevent biting. Alternatively, a protective cover is put on the mare so the stallion can’t harm her.
While the mare’s hind legs are tied in breeding hobbles to stop her from kicking as well as a twitch so that she will standstill.
These types of domestic breeding are extremely common. For sport horses, the most common type of breeding is through AI, which allows breeders to use any stallion in the world. The mare and stallion never meet.
It is less natural but safer, especially for horses that are worth huge amounts.
Thoroughbred breeding is still only allowed by in-hand, natural cover.
Do horses mate with their offspring?
Stallions are not inclined to mate with their offspring. If families mate with each other, it is because of human interference.
Can horses mate with ponies?
Ponies can breed with horses. In fact, one of the most popular crosses between a horse and a pony is the Welsh Pony x Thoroughbred. I have a very close relationship with a Welsh x Thoroughbred named Cappy.
Do horses have a mating season?
Horses are seasonal breeders so they do have a mating season. It goes from the early spring months to the late summer months.
How do horses mate? Every year in the early spring and late summer, mares start their reproductive cycle, which means it is horse breeding season.
The stallion courts and mates with the mare at their own pace. Wild and domestic horse breeding have differences because one has human influence and the other does not.
How do horses mate? Let us know your opinion below!
- (1) “Social Behavior of Horses – Behavior.” Merck Veterinary Manual, www.merckvetmanual.com/behavior/normal-social-behavior-and-behavioral-problems-of-domestic-animals/social-behavior-of-horses#:~:text=During%20courtship%20the%20stallion%20will. Accessed 19 Mar. 2022.
- (2) McDonnell, Sue. “Reproductive Behavior of the Stallion.” Veterinary Clinics of North America: Equine Practice, vol. 2, no. 3, Dec. 1986, pp. 535–555, 10.1016/s0749-0739(17)30705-8. Accessed 22 Feb. 2020.
- (3) Li, Xiao-Wei, et al. “Post-Mating Interactions and Their Effects on Fitness of Female and Male Echinothrips Americanus (Thysanoptera: Thripidae), a New Insect Pest in China.” PLoS ONE, vol. 9, no. 1, 29 Jan. 2014, p. e87725, www.ncbi.nlm.nih.gov/pmc/articles/PMC3906220/, 10.1371/journal.pone.0087725. Accessed 19 Mar. 2022.
- (4) BUKOWSKI.JOHN. “Breeding and Reproduction of Horses.” Veterinary Manual, MSD Veterinary Manual, 2019, www.merckvetmanual.com/horse-owners/routine-care-and-breeding-of-horses/breeding-and-reproduction-of-horses.
Bryanna is a 23-year-old Florida-based Grade 1 Para-dressage rider based in Florida and she has been riding for 5 years. Horses are her passion and her ultimate goal is to be selected for the US Para-Equestrian Team and represent the US at the Paralympics. She rides at Quantum Leap Farm and Emerald M Therapeutic Riding Center and her equine partners are Shane, an American Paint Horse, and Cappy a Welsh x Thoroughbred. When she is not helping at the barn, riding, or training, she is learning about horses, writing articles about them, and using her social media platforms to raise awareness for therapeutic riding and para-equestrianism, shares her journey, and advocates for greater inclusion of para-equestrian in the media and equestrian sport at large.
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