FAQ Horse Care

Baby Brain: Horse Breeding Terminology for Beginners

Mare and foal
Written by Natalie Gasper

Equine Breeding Vocabulary

Trying to master horse breeding terminology can feel like learning a second language. Whether you’re just curious, or thinking about breeding your mare or stallion, this article will cover the basic terms and slang you should be familiar with.

Horse breeding is about pairing a good mare with a compatible sire to create a foal with lots of potential. Mares produce foals while stallions sire foals. A pedigree is used to trace a horse’s ancestors to help predict things like coat color and temperament. You can use live cover or artificial insemination to breed a mare, who will be pregnant for 11 to 12 months. A mare who is used exclusively for breeding is called a broodmare.

Breeding Horses 101

People breed horses for lots of reasons. Some do it to keep a less common breed around, like the Cleveland Bay. Others want to produce the fastest Thoroughbreds or the most elegant Warmbloods.

To Produce vs. To Sire

These two terms are often confused by newbies to the breeding world.

To produce refers to a mare, while to sire refers to a stallion. A mare produces a foal and a stallion sires one.

Gestation Period

A mare’s gestation period is anywhere from 11 to 12 months or 330 to 370 days.

Equine Genetics

Many breeders place a large value on genetics because it helps them predict which traits a foal may have.

For example, a first-generation parent contributes 50% to the offspring (sire to foal or dam to foal). The grandsire would contribute 25% and so on. This isn’t an exact science because there’s always a chance a gene will mutate.

Horse Pedigrees

A pedigree traces a horse’s ancestors. In disciplines like racing and Western events, breeders, buyers, and trainers a considerable emphasis is placed on this.

Understanding a horse’s ancestry can provide insights into coat color, height, temperament, and even what disciplines he may excel in. You can learn more about horse pedigrees here.


Photo Cred: Canva

Common Breeding Terms


A stud is a stallion (male horse) used for breeding.


A stallion is a male horse that’s capable of reproducing.


A sire is a horse’s father.


A broodmare is a mare (female horse) that’s used for breeding. Some mares, due to an injury or soundness problem, are used for breeding their whole lives.


A dam is a horse’s mother.


A damsire is the sire (father) of the mare or the foal’s maternal grandfather.


A maiden is what you call a mare who’s never had a foal.

Live Foal Guarantee

A live foal guarantee is something typically offered by the stud owner.

This means you don’t have to pay the stud fee until the foal is born, stands, and nurses the mare.

Newborn foal

Photo Cred: Canva


The get is the offspring of a sire.

By / Out Of

Horses are by stallions and out of mares. Holly, by Winston and out of Jean, means Winston is Holly’s sire and Jean is Holly’s dam.

Artificial Insemination

Artificial insemination, or A.I., is one way a mare can get pregnant. This process involves using fresh, cooled, or frozen semen instead of doing live cover. A.I. may be preferred due to several factors including geographic location and safety to both animals.

Live Cover

Live cover is the opposite of A.I., or when a mare and a stallion have physical contact during the breeding (the stallion “mounts” the mare to inseminate her).


Many breeders will use a teaser stallion to see if a mare is in estrus, or ready to be bred. A mare in estrus will show interest in the stallion, raise her tail, or urinate. Mares who aren’t will avoid the stallion, pin their ears, or strike out.


Hobbles are placed on a mare to prevent her from kicking the stallion during the breeding process. Nowadays, if a mare is aggressive towards a stallion, breeders will opt for an A.I. option instead.

Stud Fee

The stud fee is how much a mare’s owner pays to have her mare bred to a particular stallion. The fees can range from $100 to $100,000.

Private Treaty

Stallion owners can use this to mean they are screening or being choosy about which mares they’ll let their stallions breed to.


Heat is another term for estrus or the time when a mare can become pregnant.


Caslicks, or a vulvoplasty, is a surgical procedure where the lips of the mare’s vulva are partially sutured together to prevent fecal contamination issues.

Blue Hen

A blue hen is a term for a mare who’s had a lasting (and impressive) effect on a breed or line (through multiple generations). Do Good is a blue hen of the racing world.


Colostrum is the first milk that a mare produces after giving birth. It’s full of antibodies, which helps provide immunity to the foal. It is important that the foal nurses within 24 hours of birth to get these full benefits.

Foal nursing

Photo Cred: Canva

Frequently Asked Questions

Q: What is a breeding mare called?

All mares can have foals, provided they don’t have any reproductive issues. Mares who are used exclusively for breeding are called broodmares.

Q: What is a breeding type in horses?

Depending on who you ask, this can be one of two things.

  1. There are three types of breeding: herd, pasture, and artificial.
  2. The three types of breeding are inbreeding (two closely related horses), pure breeding (the same lines or breeds or used, like two Thoroughbreds or two Quarter horses), and cross-breeding (two different breeds, like one Thoroughbred and one Quarter horse).

Q: What is a dam in horse breeding?

A dam is the mother of a foal.

Q: What is live cover in horse breeding?

Live cover means the mare and stallion have physical contact during the breeding process.

Q: How many mares can a stallion breed in a day?

A stallion can do live cover anywhere from one to three times a day.

Q: At what age do you start breeding a mare?

Experts and vets recommend waiting until a mare is five (when she reaches physical maturity) to start breeding. Anywhere from 5 to 10 years of age is a good starting point, though the lower end of that range is better if you plan to use the mare as a broodmare.

Q: When do you wean a foal?

Foals can be weaned from their mothers as early as four months of age, which is when their nutritional needs exceed what the mare can provide. The accepted range is four to seven months old.

Parting Thoughts

While breeding a horse can sound complicated, it’s a lot easier to understand once you’ve mastered the terminology.

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About the author


Natalie Gasper

Nancy loves retraining off the track Thoroughbreds and working with her dogs!