These days, we see an enormous increase in numbers, of those who wish to
become breeders. This applies to horses, dogs and just about every other
domestic animal. There sadly seems to be a severe
lack of knowledge, as to just what it takes to become a responsible
breeder. Many unfortunately, think it's just
a matter of finding two individuals with working
organs. Happily though, there does seem to be
some public awareness of the significance of genetic
diversity in certain individuals and the obvious advantage
of breeding animals who are closely, or somewhat closely,
related. At least within those who have sought to educate
themselves on the matter.
In some respects, Genetic diversity (outcrossing) might be considered
advantageous in the total pool of domesticated horses. However,
linebreeding and inbreeding can also have desired effects.
The total gene pool (genetic diversity) for horses is extremely large.
This is apparent when one considers all of the various
breeds, crossbreeds and numbers therein. However, this obviously
limits the gene pool for any one particular
breed. The outcome of this, restricts all animals of that
breed, to have a certain "look" and background.
In earlier years of a given breed, animals who possessed
the desired traits, were bred very closely to relatives
who also possessed those traits - hence the beginning of
the different "breeds" as we know them today. So let's
have a look at just what inbreeding, linebreeding and
outcrossing are all about. Of course there is much more
to it than that which I outline here, but it should give the
newcomer to breeding, a little idea of just what it's all about.
First however, let us dispell some myths and legends
about breeding. Inbreeding does not produce,
midgets, animals with three legs, temperament problems, infertility etc.
Similarly, outcrossing does not necessarily produce animals with no genetic problems or healthier, stronger animals! 'Hybrid Vigor" as it is known, is a myth in many respects.
You can find just as many major
problems in outcrossed animals as you can in inbred or linebred stock.
The key to ALL breeding, is to know what you are doing before you begin.
It begins with education. Learn as much as possible about your chosen breed. Study the 'Standard' of the breed. Research all you can about animals appearing in the pedigrees of those you intend to breed. Honestly evaluate their strong and weak points and don't breed with your 'heart'! Just because you have a dog or horse you love
dearly, does not mean he or she is of quality to bring into the world,
the next generation. A large number of animals
alive today, do have genetic and other problems, and if bred, only
produce more with the same defects. There are only two types of breeders. The
irresponsible and the responsible. I'll leave it up to anyone reading
this, as to which their conscience determines they wish to be.
INBREEDING is a very close cross between a given pair
of animals. This might be a son to mother, father to daughter or
brother to sister. The latter is not a common union and personally,
I can't see what it is expected to achieve.
Inbreeding should only be attempted by extremely knowledgeable breeders.
Those who are most thoroughly aquainted with all the animals, fairly close-up in
the pedigree. The breeder must have a sound knowledge of those individuals, as it
applies to their health, longevity, quality, temperament etc. Even color might play a part. Certainly, well bred and noted individuals from these types of close breedings, have been produced. They are frequently, extremely prepotent. This is also how the breeder can set 'type' in his breed.
LINEBREEDING is the breeding of two animals who are closely related
to the same ancestor or a couple of ancestors, but are little if at all,
related to each other through any other ancestors. In a linebred pedigree,
a single horse and his ancestors might appear two or more times. This has often been a preferred method of breeding, within the breeder communities. This method of breeding, does obviously not set 'type' quite as quickly as inbreeding.
OUTCROSSING is the breeding of two unrelated animals - at
least say within the first four or five generations. If one were to study pedigrees,
it is almost inevitable to often find several of the same horses appearing in the pedigree of both sire and dam. However, for now we will consider an outcross, the breeding of two horses which don't show the same horse appearing in the last four or five generations.
The purpose of both inbreeding and linebreeding is to bring improvement more rapidly and narrow the pedigree to a few closely related lines of descent. It reduces variability. It more quickly sets a 'type' in your stock. It also brings out more strongly, good and bad qualities. This also includes genetic problems which might have lain hidden before. It is easier to predict the result of a breeding by inbreeding and to a lesser degree linebreeding, than the results of a complete outcross. If the selection of the ancestors or ancestor the sire and dam have in common, is an excellent example of the breed, then it would come as no surprise that the offspring would probably be of superior quality.
Judicious inbreeding and linebreedings, have shown in all breeds of animals, a real improvement in offspring. Remember however, this only comes about if the ancester chosen on whom to inbreed or linebreed, is himself, a particularly superior example of the breed. One who has shown through his offspring, that he does in fact reproduce himself reliably. This also applies to mares if it is indeed a mare, on which the inbreeding is performed. Years ago, breeders only considered the stallion when breeding. We now (thankfully) know differently. Our mares are just as important and maybe even more important, than our stallions. The quickest and most certain way to produce superior offspring is by very careful inbreeding or linebreeding. When considering inbreeding and/or linebreeding however, one must not consider the animal on pedigree alone. Much research should be done as to his possible weak points. This must include his temperament, any genetic health problems he might have possessed and if he died young, what was the reason etc. With so many genetic problems within our animals today, it certainly is necessary to do as much research as possible on a given animal, whether he be living or dead. A horse bred on pedigree alone, without much knowledge of the horses therein - especially one who appears many times over in that pedigree, quite well might display many previously unknown genetic problems. This might be a propensity toward certain cancers, allergies, heart problems and more.
Close breedings certainly will likely bring out such ailments in offspring. It does not "cause" them, but instead displays them which obviously then allows the breeder to know just what he has in his line. Close breedings not only bring out the good and desirable traits, but those which might have been lying hidden for generations. Inbreeding and linebreeding therefore bring out in the open, the best
and sometimes worst traits, in an individual. It is again the reason why it is so important to research as much as possible about a certain stallion for example, to whom you are breeding your related mare.
There is no doubt, that all animals, have some imperfections and it is up to one's own desires, knowledge of the breed, knowledge of genetics and certainly one's conscience, just which faults one is willing to overlook in an otherwise spectacular example of a given animal. It is always unwise though, to double up on a fault. If your mare has a particular fault which is not correct and you find objectionable, then it should be obvious that you wouldn't breed her to a stallion with a similar fault. In fact, she should be bred to one who is excellent where she is faulty - if indeed she is breed-worthy at all.
Offspring of two unrelated horses, cannot be reliably predicted. They might resemble the sire, the dam or neither. If however, the product of an outcross shows himself or herself to be of quality, it is prudent to bred them back into the strongest (most correct) line of their parents. So if one has set a certain type within a breed, which is now producing itself reliably, just when 'does' one decide upon an outcross?
Certainly with an outcross breeding, you might possibly lose a certain amount of that 'type" which you have previously sought. However, should you find that your heavily inbred or linebred foals are displaying some unwanted features, then it's probably time for an outcross. Again though, only chosing supreme examples of the breed. Once again, using an outcross Stallion to your mare/s, you would want to make sure you do very careful homework as to his background, what he has produced, noting his faults etc. Sometimes an outcross can bring a pleasant surprise and then one might consider breeding back into the line which the foal most displays. Always remember however, an outcross can sometimes bring the most unpleasant surprises and the breeder might lose what he has worked for in previous years, eliminating some of his ealier stock's good qualities.
Regardless of whether you wish to inbreed, linebreed or outcross, the main objective is to produce the best possible animal in the next generation. Without lots of research, homework, study, knowledge of the breed and its Standard, you can never hope to produce that which you have in mind.
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