Dutch Horses Unlimited has brought Dutch warmblood horses to New Zealand. Dutch warmbloods are renown for their performance in both the dressage and show jumping arena. Many world class sport horses have their origins in Holland. If you want to breed your mare to a Dutch warmblood horse, Dutch Horses Unlimited is the first address to enquire.

The Dutch warmblood studbook has a sophisticated breeding scheme. The performance of Dutch warmbloods in competitions is recorded, and based on that information, breeding values are derived. This way, all horses in the studbook have a breeding value for show jumping and dressage, as well as for numerous exterior traits. These breeding values are published on a yearly basis. In order to make the best use of this information , Dutch Horses Unlimited has provided a method to select a stallion from the population, which best matches your mare to achieve the breeding objective you want. An explanation of how it works can be found below.

Breeding is combining parent animals in such a way, that you have the best chance to get progeny  which has the genetic capabilities you desire. In horse breeding, the starting point is usually the mare, for which a suitable stallion has to be found, that, in combination with the mare, gives the highest probability to generate a foal that will meet your requirements.

Dutch Horses Unlimited assists you to find the stallions that meet your breeding objective. Although many of the stallions are not directly available in New Zealand, Dutch Horses Unlimited can help you to find other stallions that meet your needs.  

How to choose a stallion for your mare.

1. Introduction
2. Concept of breeding indexes
3. How to fill in the form
4. Describe your mare and the foal you want to breed
5. What is ... ?
6. Example

Introduction

Animal traits are controlled by genetic and environmental factors. In animal breeding and genetics, we normally look at the variation of genetic and environmental factors in a population. If much of the variation in the trait is determined by genetic factors, we say that the trait has a high heritability. When a trait has a high heritability, we can improve the trait effectively by breeding. When the heritability is low, it is more effective to manipulate the animals environment, or the way we handle and/or train the animals. For example, female fertility traits are known to have a low heritability. This means, that there is no point in trying to improve the fertility of the next generation of mares by selecting the animals with a higher fertility.  It's better to have a better heat detection system, improve the quality of work of inseminators, improve timing of insemination etc. On the other hand, traits like musculature are known to have a high heritability. So it is effective to change the musculature of the next generation by selecting those stallions which are known to inherit this trait.

Several traits are easily measurable on an individual animal. For example, when we look at the shape of the hoof, we can classify a hoof as being wide or narrow, or anywhere in between, and score accordingly. In how to fill in the form a description is given of all traits which are being measured by the Dutch Studbook KWPN, and for which breeding indexes are calculated. The breeding indexes for sport and conformation are based on a rather complex, but accurate animal model, that take into account the performance of the animals themselves, their offspring, and their parents. A value of 100 for a particular trait represents the average of the Dutch population for that trait. 

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Concept of breeding indexes

In order to be able to give a qualification of a breeding animal, we need to know how much of a certain trait will be inherited by the next generation. For example, if you have a breeding mare with a light musculature of the neck, you want to know which stallions qualify to improve this trait in the next generation. In other words, which stallion has a high "transfer rate" for this trait? The "transfer rate" is what is normally called a breeding index. The breeding index is an estimation of the rate at which a certain trait is transferred to the next generation. The best estimate for the breeding index of the next generation, eg the foal you want to breed, is the average between the breeding index of the stallion and the breeding index of the mare. So if the BI for  musculature of the neck of the mare is 92, and you want to breed a foal with a BI for this trait of 100, you need to select a stallion with a BI of 108. ((92 + 108) / 2 = 100). The more traits you want to take into consideration, the harder it gets to find a stallion that meets all requirements.

There are also indexes for performance: a BI for Jumping and a BI for dressage. The estimation of these numbers if a fairly complex matter, and is based on the animals' own performance, and the performance of offspring, sibs, half-sibs and parents.

The breeding indexes for sport performance (jumping and dressage) have a standard deviation of 20, which means that approximately 66% of the population has a breeding index for these traits between 80 and 120. It also means that approximately 16% of the population is below 80, and 16% is above 120. 

The breeding indexes for conformation have a standard deviation of 4. This means that if we consider every individual trait, that approximately 66% of the population has a value between 96 and 104. Approximately 16% has a value below 96, and 16% has a value above 104.

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How to fill in the form

With respect to conformation, the table below represents the traits which are taken into consideration. A value of 100 indicates that the trait is average for the population of Dutch Horses. The two columns indicate the meaning for values below or above the average.

For a mare, you should be able to score each individual trait. When you want to breed the mare, there may be certain traits that you want to improve, or correct. For example, you may have a mare that has a relatively short neck, and you want to breed a foal with a longer neck. In this case, your mare may have a score of 106, and ideally, you want to breed a foal with a score of 100 for this trait. Also, your mare's posture of trot may be pushing, and you want to breed a foal that is more lifted. The mare scores, let's say 96, and you want to breed a foal that will score 104.

You can see here that you don't necessarily need to breed for a high score for a conformation trait. You just need to specify what your breeding objective is. This may also apply in a way for the breeding indexes for sport. You may want to breed a typical jumping horse, or maybe a typical dressage horse.

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Describe your mare and the foal you want to breed

When you fill in the form, you first need to check the traits that you want to take into consideration for the foal to breed. Then you need to score the value for these traits of your mare. Subsequently, you need to indicate the values for the foal you want to breed. When you submit this form, the selector will come up with a list of stallions that give the closest match. With respect to the breeding values for sport, you fill in the value for the mare, and the minimum value of the breeding index that you want the foal to have. In that case, stallions that will breed a foal with an index above the target value will be considered equally good for that trait. For example, let's say your mare has a breeding index for dressage of 112. You want the offspring to be a really good dressage horse, so you want the foal to get a value of 130 or higher. In that case, the stallions that have a value of 148 or higher (this will yield a BI for dressage of (148 + 112) / 2 = 130, will be considered as equally good. The final ranking will depend then on the ranking based on the other traits that you have taken into account.

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What is ... ?

Heritability: : the part of the total variation of a trait within a population (phenotypic variance), which is determined by genetic factors.

Breeding index : the amount in which an animal transfers a certain trait to the next generation. The breeding index of the next generation is equal to the average of the breeding indices of the two parents.

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Example

Let's assume that you have a mare, with a BI for jumping of 105, and a BI for Dressage of 118. You want to breed this mare, and your target is a foal with a high BI for Dressage and an average BI for Jumping.

When you have chosen your language from the home page ("English" in this case), you subsequently select "Stallion Selector". You will then see a table where yu can enter the scores for conformation of your mare. They are set to 100 by default (which is the population average).

When you scroll down, you can enter the BI for Jumping and Dressage of your mare. A value of 105 is close to the average, and you leave this value unchanged. A BI of 118 is above average, and you click on the third circle from the right hand side for the BI Dressage.

Further down, you have the section for the foal you want to breed. First, you seen the conformation section, and below are the BI's for Jumping and Dressage. In the first place you wanted to breed a foal with a high potential for Dressage. When you check the box on the left hand side of the line for Dressage, you indicate that you want to take this trait into account in your selection of stallions. You also click the circle on the very right hand side of this line, to indicate that you want the highest possible BI for dressage.

You also wanted an average BI for Jumping. You need to check the box on the left hand side of this line, to indicate that you also want to take this trait into account. If you then click on "Submit", the system works out which stallions, in combination with the mare you described, will breed the foal that comes closest to your desires.

When you click on the names of the stallions, you will see a graphical representation of the conformation and sport traits of the foal that will result from the combination of this stallion with your mare. So you can get a prediction of the traits of your foal. When the traits were not taken into account in your selection of stallions, the bars will show in light blue. If they were included, they will show in red.

As you can see, you have predominantly selected stallions with a high BI for jumping. Your target was to breed a foal with a high potential for dressage, but because you also have (relatively) high demands on the Jumping trait, the system needs to find stallions that meet both your requirements. Obviously, there are only few stallions with a very high BI for dressage, and an above average BI for Jumping.

When you return to the input form for the foal to breed, and indicate that you don't want to take the BI for Jumping into account (by un-checking the box on the left of that line), and resubmit, you'll see a totally different list of stallions. In this case you selected the the stallions with the highest BI for dressage.

You can also see, that the foals that would result from these stallions, would have a below average BI for Jumping.

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