Mare Owner's Guide

If you are thinking of breeding from your mare, we have put together this handy guide to help owner's make informed decisions about their mare and any future foals she may have. FHAGBI promotes responsible breeding in accordance with the breeding rules and regulations of the KFPS. This is to ensure standards are maintained at the highest possible level and inbreeding is kept low. The KFPS have a comprehensive fertility brochure that is a must-read for any potential Friesian breeder. The link for this can be found under the 'Downloads' section.

There are many factors to consider when deciding whether or not to breed from your Friesian mare.

Mare's pedigree

Ideally the mare should be in the main Studbook (Stamboek, Stb), or, if in the Foal Book (Veulenboek, VB), B-Book I or II (Bijboek I or Bijboek II) the rest of her breed-line should preferably be in the main Studbook.

Mare's health

Before any mare is put into foal, it is highly recommended she has a Breeding Soundness examination. This will involve a general health check, external and internal reproductive tract examination, which may or may not include ultrasound examination of the uterus and ovaries. Prior to AI or going to stud, the mare should be tested for Equine Viral Arteritis – EVA (via a blood sample) and a swab taken for Contagious Equine Metritis – CEM. Both these diseases can cause major infertility problems. If you are planning on sending your mare to a stud to be inseminated, it is important to check with them for their health/test requirements on boarding mares.

If your mare has arthritis or a joint disease such as osteochondrosis, or a immune/skin disease such as sweet itch, again you really should question if she should be bred from as there may be a genetic link. Not to mention the need to consider the health and welfare of the mare herself. If your mare has a tendency to ‘milk off her back’ (i.e. lose a great deal of condition), then give her a year or two off between foals to replenish her body reserves and most importantly her mineral reserves, and consult one of the horse feed companies’ nutritionists as how to feed to ensure she maintains some condition.

Additionally, if the mare has a conformation or movement defect that has prevented her entry into the Studbook then she really should not be bred from as it may pass onto the offspring.

Finally consider the mare's age. If she is an older, maiden mare, always seek the opinion of your vet/breeding specialist who should be able to advise you on any age-related concerns. Additionally, putting a Friesian mare in foal at two years of age to foal down at three is unacceptable and is not condoned by FHAGBI nor the KFPS.

Lineage verification and DNA testing

As from September 2017, in addition to lineage verification, all mares that are declared Ster and all mares with a foal accepted for registration also need to undergo DNA testing for hydrocephaly, dwarfism and the chestnut factor.

Finding a suitable stallion

There are many factors to consider when deciding which stallion to use for your mare. Breeders should select a stallion whose conformation, movement, sports performance and pedigree will best complement the specific mare for the particular purpose for which the mare is being bred. FHAGBI recommends that only main Studbook mares are bred from with semen from an Approved Studbook stallion. If you decide that you are going to use a non-approved Friesian stallion to cover your mare, please ensure he is in the main Foalbook, has an excellent, full papered pedigree (all mares in pedigree Ster, Ster-Pref, Kroon, Model, or Model Pref) and that he has been to a grading and received the Ster predicate. Additionally, check the inbreeding percentage of the stallion with your mare. FHAGBI strongly discourages the breeding of Friesian mares to stallions of other breeds and no registration papers will be issued to the offspring of such breeding.

  • Complimenting your mare - Not only is it important to use the best-quality stallions, but it is even more important to make the correct combinations. In choosing a stallion you must determine what weak points of the mare you want to improve and what strong points you want to embed. As an aid in determining the strong and weak points of the horse, you can use the linear scoring form. This is drawn up at the inspection for the mare's Studbook registration. Then you look at the heritability performance of the stallions. This data can be found on the website of the KFPS and additionally are distributed annually with Phryso. For example, if your mare has a weak/low-scoring trot, it would be wise to use a stallion with a high-scoring/heritability trot, so complimenting your mare.
  • Inbreeding Co-efficient – All Friesian's have an inbreeding co-efficient, which is the percentage of how much their sire and dam are related to each other. The KFPS recommends to aim for inbreeding co-efficients less than 5%, less than 2% is ideal but anything less than 12% is acceptable. There are an increasing number of Friesian's being bred nowadays with 0% inbreeding co-efficient. A simple rule of thumb is that in a foal’s pedigree, no one name should appear more than once within the first three generations (parents, grandparents, great-grandparents). In selecting a stallion, the mare owner has the responsibility to consider carefully the inbreeding coefficient and kinship percentage of the resulting foal. It is not an absolute criterion by itself, but should be considered in conjunction with other factors such as desired conformation, intended use, height, etc. If you are a Gold member of FHAGBI this will give you membership to the KFPS and website access to their inbreeding co-efficient forecast, which calculates the percentage of inbreeding for foals resulting from the mating of a particular mare with a particular stallion.
  • Semen availability - You will need to check with the stallion stations as to the availability of semen for export. Semen from popular stallions may need to be reserved a year in advance. The KFPS are encouraging more studs to become EU-licensed so we hope that there will be a bigger choice of approved stallions in the near future.
  • Intended use - When choosing a stallion it is important to know what the intended use of the foal will be. Do you want to breed a foal for sports performance, such as driving or dressage? If so, take this into consideration when deciding which stallion to use by viewing its own relevant sports performance and also offspring performance.

Click here to read more about approved stallions and the all the relevant stallion information/links from the KFPS.

Stud service

Once you have decided on a stallion, the decision over where and how the mare is to be impregnated needs to be made. Live cover and Artifical Insemination (AI) are the two approved methods, however, the majority of approved stallions do not offer live cover so this leaves AI as the only option. For mare owners in Great Britain and Ireland, there are two options;

  1. Artifical Insemination via exported semen. Providing the stallion is standing at an EU-licensed station and provides chilled and/or frozen semen, it can be exported to the UK to be used to inseminate the mare by your own vet/breeding specialist. They may also have stocks of frozen semen for export from stallions which were previously standing at their stud.
  2. Send the mare over to a Stud in the Netherlands to be inseminated.

For more information on AI in the KFPS Registered Friesian, please download the AI guide found on this page.

For more information on Embryo Transfer, please click here to visit the article on the KFPS website.

Pregnancy care

The gestation period of a horse is approximately 320 to 365 days, with most mares averaging between 330-345 days. Once your mare's pregnancy has been confirmed it is fairly easy to work out an approximate foaling date from the date of service.

Throughout pregnancy, you should ensure that your mare receives adequate nutrition, especially through the winter, ideally lots of forage complemented with a quality stud balancer. During the last 3-4 months of pregnancy, she should be on an increasing plain of nutrition to enable her to cope with the demands of her developing foal, without allowing her to become overweight. Check with your vet regarding your mare's worming schedule as some wormers should not be used on pregnant mares. Providing your mare is fit and has no complications, she can still be ridden throughout the first half of her pregnancy, although it is advisable to stop riding after approximately 200 days gestation. If you intend to ride your mare, speak to your vet about the length and type of exercise you plan on doing with her and they should be able to offer some guidance.

The end is near

There are a few signs owners should look out for during the weeks leading up to the mare's foaling date. Approximately a month before foaling, many mares start to develop oedema low in their abdomen. At roughly the same time their udder begins to enlarge, accelarating in size about 2 weeks before term. A few days before foaling, the udder softens and fills with fluid that slowly changes to thick colostrum. The colostrum is generally present 1-2 days before birth. Softening of the pelvic ligaments will occur at this stage and the mare's tail-head may appear more pronounced. A mammary secretion, known as 'waxing' usually appears about 1 day before birth and in the last few hours some mares will start to drip milk from their udder.


The majority of mare's give birth during the night/early morning. Common signs of the foal's imminent arrival include restlessness, kicking at the belly, looking towards the flanks, and the mare generally seeming irritable or anxious. Some mares may pace, lie down and get up regularly or stand as if planning to urinate without actually doing so. Once you begin to see these signs, it is likely that your mare is in the first stage of labour and her foal will soon arrive. Owners should ensure the mare is in a secure, quiet place (foaling stall or paddock) and allow them the space and time to begin to foal without undue stress or interruptions. A remote camera mounted in the foaling stall/paddock allows an owner to keep track of the mare’s progress without interfering. Most mares will birth without any complications at all, but if at any stage you are worried, do not be afraid or embarrassed to phone your vet/breeding specialist. Far better an out of hours call out charge than a poorly mare or foal.

Post-partum care

Providing the mare has had an easy, straight-forward birth and the foal is feeding well, it is best to leave the new Mum alone with her foal for the first 24 hours or so. As tempting as it is to fuss over the new arrival, allow the pair time to bond quietly all the while maintaining a watchful eye.

Although a huge commitment, following your mare's journey through pregnancy and watching a foal from birth to maturity is a very worthwhile and rewarding experience. There is alot to consider when thinking of breeding from a mare and we hope you have found this guide helpful. If you have any further questions about breeding, please contact Vicki Knapp -, who is an experienced Friesian breeder and will be happy to offer advice.

Click here to read details on the process of registering foals with the KFPS.