Conformation And The Breeder
by Dr. Robert Baird
Part I Part II Part III Part IV
When a sport horse breeder first looks at a horse he will be impressed by those qualities which he is trying to produce in his own breeding program. He will evaluate a stallion or mares potential for passing on certain characteristics; and every horse, including geldings, may provide information on the heritable qualities of the parents.
A rider sees a horse from another perspective. It must demonstrate in temperament, conformation and movement its suitability for a specific discipline. This varies with the discipline and the level of performance the rider hopes to achieve, but ultimately both breeders and riders seek the same qualities in their horses. They want horses that are even-tempered, athletic and are well conformed.
Although directed primarily at the breeder, this article applies equally to the rider, whether the objective is upper level competition or simply non-competitive pleasure riding.
The value of the qualities mentioned above - athleticism, a good temperament, and acceptable conformation - may vary slightly with our goals. For instance, a prospective buyer who hopes to take a horse to advanced level will avoid one that fails to move well, even though it has a good temperament and acceptable conformation. For the same buyer, a horse that shows natural athletic ability, a good temperament and acceptable conformation, will be judged much more favorably. On the other hand, a rider who is looking for a field hunter will be very interested in having a horse with a reliable temperament and which is able to carry weight and stay sound. Outstanding athletic potential may be of limited value to him, as the horse may never be asked to jump higher than three feet six inches.
A horse being judged primarily for athleticism is best seen in conditions creating the most positive first impression. Thus, if seen moving at liberty, and in a quiet, excitement-free and relatively small enclosure, then balance, rhythm and natural self-carriage may be readily observed. Especially at the canter and trot, but also at the walk, the athletic horse will flex his loins, raise the base of the neck and demonstrate the impulsion and thrust we associate with one which will be a pleasure to ride and train, and which will stand up to work. If he moves well and appears to have a good temperament, the decision can be made later whether his conformational shortcomings are acceptable.
* * *
The form of the horse varies with the function it is expected to perform, so that, before attempting to judge a sport horse, it is important to know what type we are looking for and what its function is to be. Is it for jumping, dressage, eventing, driving, endurance or any other discipline? Although there are some variations of conformation which are discipline-specific, most of the desirable qualities are common to all sport horses. Bio-mechanical efficiency permits ease of movement, which, in turn, reduces trauma and encourages soundness.
For present purposes we will confine the discussion to horses being selected for the three Olympic disciplines of Show Jumping, Dressage and Three Day Event.
The goal in any breeding program is to produce foals that are at least as good as their parents, hopefully better. However, there is reliable evidence that 25% of all foals do not live up to the qualities of their sire and dam, and another 25% make only serviceable riding or pleasure horses. So that 50%, or one in every two foals, are only fair or poor compared to their ancestors. In any other endeavor, a 50% relative failure rate would be very disappointing.
The best chance of obtaining genetic excellence in a sport horse occurs when it has well-conformed parents that themselves have good performance results. Occasionally we will see an outstanding performer whose parents and close relatives have not performed, or at any rate have not done so with distinction. That individual may represent a rare and valuable new line, but it is advisable to treat so-called new lines with caution when making a breeding decision. Once the breeding choice has been made and the foal is on the ground, what you see is what you get, regardless of the qualities of the parents.
Phenotype is the term used to describe the outward, visible structure of the horse, sometimes referred to as surface anatomy. But it also encompasses the internal anatomy of the animal, and includes the physiological function of the heart, lungs, digestion, central nervous system, and so on. In addition, the word phenotype is also used to include performance and relatively high heritable traits. In contrast, the genetic constitution of the horse is known as the genotype.
It should be accepted for our purposes that athletic ability in the horse is determined by the phenotype and is detectable by examination.
Breeders can increase the likelihood of success significantly by:
- studying the conformation of sire and dam and analyzing it correctly;
- understanding the relationship between conformation and performance;
- mating and culling to correct or eliminate conformational weaknesses;
- recognizing objective performance records.
By emphasizing the qualities that allow for greater athletic potential, we minimize the likeliness of unsoundness and breakdown. So we should concentrate on what we want and why we want it.
Sport horse breeders are restricted in many respects to a fairly narrow range of type. They are often forced to keep it even narrower than they would like, depending on the market place and the demands of the buyers.
If buyers know what is the best conformation for their particular discipline, the breeder may have to anticipate that and produce, for example, horses more suited to dressage than to hunter or jumper, and that anticipation may be narrowed further, depending on the level of accomplishment which the riders hope to reach. These two disciplines may sometimes accept variations in conformation, but certain basic requirements are almost always the same.
For a breeder purchasing breeding stock, or trying to decide which stallion to breed to which mare, or a rider or competitor selecting a horse for competition, a certain amount of judgment is required. And we all do some form of judging every time we look at a horse.
Such judgment is not easy for everyone. Many international riders are wary of buying a young horse on conformation and pedigree alone. Most prefer to know and see what it is capable of doing in their discipline. It may cost them more initially, but often less in the long run.
What, then, are the considerations we must be aware of when making a selection, and how should these considerations be prioritized?
When trying to forecast how an unproven horse will perform, or even how he will look when fully developed, there are three criteria we should consider:
- The conformation and natural athleticism of the individual;
- Physical similarities to close family members;
- Performance results of parents, siblings and ancestors.
Again, the order is important. If we see two horses side by side, one really good looking and correctly conformed, but on which we have absolutely no information, and the other poorly conformed but with good information on his pedigree and ancestors performance records, we will almost always be safer to choose the well-conformed for breeding purposes.
Members of a specific breed association are sometimes overwhelmed - occasionally blinded - by the bloodlines of the horse in front of them, and may forgive an otherwise unforgivable defect. They may even get defensive by recalling the outstanding performance record of a close or even distant relative, in spite of a significant conformational flaw.
After deciding what to breed, the breeder should have reasonable hope and expectation, but ultimately must accept the foal on the ground. What you see is what you get.
Mating to correct weaknesses of conformation merits special mention. By way of an example, breeders may breed a long-backed horse to one with a short back, in an attempt to produce a foal with a back of desirable length. However, we know that over 90% of all mammalian traits are controlled by multiple genes, while simple Mendelian genetics apply to less than 10%. The length of a horses back is controlled by a number of factors. These include the length of the vertebral bones themselves and the width and compressibility of the inter-vertebral discs. Each of these factors, in turn, is controlled by several genes, producing the possibility of a large variation in back length. Therefore, a long-backed horse might have long vertebrae and normal disc width, while a short-backed horse might have normal vertebrae and narrow discs, and there can be any combination of these variables. In general, the length of a horses back will lie somewhere between the lengths of the parents backs. Rarely, the result will be a foal with a longer back than either of the parents. For the breeder, however, the best chance of success is to cull the long-backed horse and breed with two horses both of which have backs of desirable length.
Conformation judging is a process of observation which can determine whether a horse will move well, carry weight and stay sound. It is not a system of fault picking, and breeders must avoid the over-analysis of minor flaws in conformation. Paralysis by Analysis is a common problem in many of lifes pursuits, and is not unknown in the horse world.
The equine and human, both being mammals, have many skeletal similarities, and it may be useful if the human skeleton is visualized when considering the layout of the bones of the horse.
90% of conformation is the result of bone structure. The lay-out of the horses bones, their lengths and the angles which they create with each other, plus their muscular and ligamentous attachments, produce what we call conformation. They control how the horse stands and moves in all gaits, and also how he jumps.
To learn about the bones and their angles, we must be familiar with the points of the horse, and following are some desirable bone relationships and proportions (Figure 1). They will be discussed in some detail later, but in general it should be accepted that the horse will be more bio mechanically efficient the closer these relationships are to the ideal.
- In a rectangular frame, the body length (point of shoulder to point of buttock) should be about 10% greater than the height at the withers.
- The back (pt. of withers to pt. of croup) should be less than 50% of the body, preferably 45%.
- The rib cage length (pt. of withers to last rib) should be greater than the length of the back. (105%)
- The last rib should be no farther than 6 inches from the point of the hip.
- The pelvic length (pt. of hip to pt. of buttock) should be at least 1/3 the body length.
- The pelvic angle should be greater than 15°.
- The peak of the withers should be behind the point of the elbow.
- The arm (pt. of shoulder to pt. of elbow) should be at least 1/2 the length of the shoulder.
- The shoulder / arm angle should be at least 90°.
- The pastern should be 1/2 to 3/4 the length of the cannon bone.
- The stifle should lie directly below the point of the hip.
- The femur should be longer than the gaskin.
- The stifles should be further from the midline than the hips.
- The stifle should be lower than the elbow.
- The hock should be higher than the knee.
- The depth at the groin should be close to the depth at the girth.
Good conformation is desirable, not because it looks the best, but because it stands up the best. It is always refreshing to see a horse with a conformational weakness perform with excellence against all expectations. We must be aware, however, that, in such a case, the performance occurred in spite of the defect, not because of it.
So far, therefore:
- Conformation depends largely upon bone structure.
- We should know the points of the horse, and, if possible, the names of the bones.
- We should know what effect proportional differences have on conformation and movement.
We are looking for sound, fertile, long-lived and athletic horses, and should treat fashion with caution.