Selecting a Friesian stallion for your mare

It is a challenging activity – selecting the right stallion for your mare. When choosing a stallion it is not just important to use the best-quality stallion or use a stallion you “like” but it is even more important to make the correct combinations. The NZFHS and KFPS strive to make as many breeding data on its stallions available as possible.

What are important factors in making a decision as to which stallion you will breed your mare?

There are a number of factors that you need to consider. They are your breeding goal, your budget, the inbreeding % to a specific stallion, and the strong and weak points of your mare and whether she is carrier of some of the genes that produces “faulty” foals. Let’s have a look at all those factors.

Determine your breeding goals first.

First a breeder needs to determine what the goal of the breeding is. Examples of this may be:

  • a modern, sporty, athletic Friesian for dressage competition
  • a harness type for show driving or a horse for combined driving
  • a more classical, or baroque type Friesian
  • A wonderful, reliable pleasure horse that can be in the paddock for months and then gets saddled for a ride
  • To produce a breeding mare or stallion

Especially if you are a breeder, quality is one of the most important factors and breeding a studbook mare to a studbook stallion comes closest the breeding goals of the KFPS.

Costs would be another factor to consider. If you are breeding to a studbook stallions, that means importing frozen semen yourself or through a third party. It is costly and has a higher risk of failure and your expenses might dramatically increase because of that.

Which stallion to select? One of the choices you have to make is between selecting an approved studbook stallion or a foalbook stallion with a breeding permit. If you own a main studbook mare, you would like to have the foal into the main studbook too and therefore you need to breed to a studbook stallion. The alternative is to breed to a foalbook stallion (who is also in the main book) with a breeding permit. This is “the next best thing” to a studbook stallion, as they would have come close to be selected as studbook stallion. The advantage is that the stallion is in the country and you can most likely obtain chilled semen. This will enhance the chances of the mare getting pregnant. While with frozen you usually get enough straws for up to three inseminations, chilled semen can be collected at any time. You are also more likely to get a LFG from the stallion owner while this is not the case with most studbook stallions. With some studbook stallions however you can request additional straws or receive a refund for the service fee part of the costs.

What are the differences between an approved studbook stallion and a foalbook stallion with a breeding permit?

A studbook stallion has been through a rigorous selection process, consisting of 4 steps:

  • First round of selection (normally in the Netherlands or the USA). Followed by skeletal x-rays and semen quality tests.
  • Two subsequent rounds of selection during the stallion keuring/show in January in Friesland each year.
  • Central (performance) tests (70 days) in autumn each year for the young stallions (from approximately 3 ½ year old), or in spring for the older stallions. If passed a stallion will be admitted to the studbook and be awarded a provisional license with a breeding limit.
  • Progeny performance testing over 3 generations. Offspring will be selected and has to undergo a performance test (ABFP).

Progeny of a studbook stallion and studbook mare are admitted to the studbook as adults if they pass the selection process at a keuring. Progeny of a studbook stallion and a B-book I mare will be eligible for the B-book I register. For all rules see article about books and registers under menu item “breeding rules”.

Note: A studbook stallion is recognizable by a 3 digit number after the name, eg. Jasper 366, Beart 411. The name and sequence number is given to them by the studbook once they are approved for entry into the studbook.

For a foalbook stallion to be issued with a breeding permit, the following conditions have to be met:

  • Must be a “ster” stallion of very good quality (eg, scoring high for racial type and movement), and must be registered in the Main Book foalbook section.
  • Preferably having passed one or two rounds of the stallion selection as a minimum.
  • Be DNA checked (eg. chestnut factor, dwarfism, hydracephalus), satisfactory semen analysis and satisfactory full skeletal X-ray of all joints.

They also must have successfully completed an IBOP test or equivalent (eg. ABFP or achieved high level in sport). Additionally they must make a positive contribution to the breeding in a specific country.

Depending on the status of the mare, the resulting foal will be eligible for B-book I or B-book II.  The table 1, indicates what the results of different breedings are.

What if I breed to a stallion without a permit? If you breed with a foalbook stallion without a permit, the resulting foal can only be admitted to the B-book II. It needs two additional generations of breeding to a studbook or foalbook stallon with a permit to have the offspring back to B-book I. If you breed to a foalbook stallion without a breeding permit, the breeding results are much less predictable as you breed to a much more unknown quantity. Of course this is dependent on the breeding and performance of that particular stallion.

Table 1 registration process

Stallion →

Mare        ↓

Main studbook Foalbook (in Mainbook only) with breeding permit Foalbook in Mainbook/ Bb I/ Bb II
Main Book Main book Bb I Bb II
Bb I Bb I* Bb I Bb II
Bb II** Bb I Bb II/ BbI** Bb II

*           After use of 3 Studbook stallions in the last 4 continuous generations in the motherline the progeny of the Bbook I mare are registered in the main studbook

**         If the Bbook II mare is bred to a foalbook stallion with a permit, promotion to Bbook I takes place in 2 generations. Is the Bbook II mare bred to a studbook stallion, then promotion takes place in one generation.

The other factors in a making a decision about which stallion to use are:

  • Inbreeding percentage – it is important with the Friesian Breed to keep this below 5 %. The inbreeding % can be calculated for studbook stallions on the KFPS website. Alternatively, for studbook as well as permit stallions you can e-mail the society and request a calculation to be done.
  • Matching your mare to a stallion and improve on the less strong points of your mare. When your mare was admitted to the studbook, you would have received a linear score result. This will provide details about the strong and the weaker points of the mare. Selecting a stallion that would improve some of these weaker points is important. For studbook stallions you can use the breeding value indicators that are available for each stallion, for permit stallions, you can use the linear score results that you can request from the stallion owner or lookup on the KFPS website.

The approximate relationship between the linear score results in the upper part of the form are shown in table 2 below:

Linear score 5 10 15 20 25 30 35 40 45
Breeding values 84 88 92 96 100 104 108 112 116

On the linear score sheet or the breeding values of your mare determine which characteristics you want to improve. The diagram on the left shows the values of the mare. The length of the walk is short, so you need to select a stallion that has a longer stride in the walk. The diagram on the right shows the breeding values of a stallion that has a good length in the walk.

In general, the colours in the stallion values indicate whether they are unfavourable (red, to the left), favourable (blue, to the right) or optimal values ( light blue). The optimal values are always closest to 100.


If your mare is a carrier of one of the two “faulty” genes, that causes dwarfism or hydrocephalus, do not pair with a stallion that is a carrier also. This increase the risk of a foal born with a fault very sharply. Information about your mare can be obtained by having a DNA test done. For stallion information, you need to discuss this with the stallion owner or the KFPS.

Does your mare conceive to frozen semen? With some Friesian mares it will be difficult to achieve a pregnancy to frozen semen. Frozen semen quality has already suffered because of the freezing process and may have a progressive motility of less than 40 % compared to at least 70 % of chilled semen after 24 hours. Only experience will tell whether your mare conceives successfully with frozen.

Summarising, selecting a stallion for your mare is not that simple as you want to have the best possible result. Many factors come into play and it is always important to look beyond the fact that a stallion looks impressive because he has to complement your mare in quite a few other ways. Asking for advice is a good thing and there are many sources for information available. The societies such as the NZFHS and of course the KFPS, stallion owners and experienced breeders are always willing to give advice!