Summary
What is true of humans, horses, cattle, pigeons. and every variety of animate beings is, of course, equally true of dogs: By inbreeding and line breeding we intensify both the merits and the faults of the original foundation parents.
The Syrian tribesman Terah must have had a strong, healthy body and a keen, lively and judicious mind. The cow Rhea must have had much more than a productive udder to commend her highly for being bred upon so heavily. Dreadnought (the Abraham of homing pigeons) must have had not only a deep keel and strong wings, but must have been perfectly balanced throughout. Cottage Queen (the first hen to lay an egg every day of the year except Sundays and Bank Holidays) must have had no ovarian blemish to bequeath to her countless daughters.
We as dog breeders, when considering inbreeding and line breeding, MUST remember that outstanding quality is good; indeed, it is excellent, but the absence of similar faults or shortcomings in the mating pair is every bit as important. We must also remember that by using as our tap-root, or foundation, animals for inbreeding or line breeding two specimens having a similar fault, it is far more easy to establish that fault in our strain than had we used some other type of mating.
Any student who will take the trouble to study the original forebears of any strain in any species of livestock will find that inbreeding and line breeding have played a large part in creating their type. There is a persistent belief that such breeding endangers virility and fertility, but the absence of the latter essentials to existence is, in any case, very common, inbred or not.
Many domestic animals are weakly, many are sterile, and any tendency in that direction in a parent becomes, of course, doubled by inbreeding. This belief, therefore, becomes re-established by the experience of those who have inbred their stock WITHOUT ADEQUATE SELECTION OF SOUND SPECIMENS.
Part VIII
In these, the final installments of the series which has been appearing for several months, I have been asked to supply both a summation, and some examples, of planned matings.
First, it must be recognized that all faults. Excellencies, capabilities and diseases of all living matter can be divided into two categories, depending entirely on whether they are (I) inborn, or (2) acquired.
To obtain a proper understanding of these two terms, it is necessary to study briefly another point. All life has its origin in what is .known as the living "cell." the lowest form of animal life consisting entirely of one single cell. As the animal forms rise to a level above this simplest type of life, more cells are added and the creature becomes an organism of multi-cellular life.
The cells of which an animal is composed are of two kinds: the pro-creative germ, or birth cells, and the body cells The first of these, the germ cells, are the most important in planned breeding and are the result of the fertilization of one cell, the ovum of the female, by another germ cell, the sperm of the male. Because these cells are the true bearers of the heredity of the individual, and their chromatin material passes on from generation to generation. these are the ones with which we are concerned in this study.
The second group of cells
The body cells are essentially covering or protective cells. In higher animals they are always associated with the idea of protection and use and are of various kinds; such as, muscle cells, bone cells, skin cells, etc.
Because we are here mainly concerned with the matter of heritable characteristics, rather than acquired, little need be said about the latter. It might be well, however, with the object of clarification in mind, to consider briefly some differentiation between the two groups of cells뾲his particularly because. I have found, there is confusion in the minds of some beginner dog breeders as to what constitutes inherited characteristics in contrast to those which are acquired.
So very many ask, when some fault of their dog is pointed out to them. "Can I do any-thing to correct it?" or "Will exercise improve the condition?" They thus indicate their confusion over the two types of cells. It seems to me that unless an understanding is had on this matter, there would be little help given to novices in the breeding art by the further consideration of a breeding program.
As is well known, there is never any growth without the stimulus of nourishment of some kind. Thus the GERM cells develop under the stimulus of nourishment, while the growth of BODY cells comes through the stimulus not only of nourishment, but also of use or injury. As examples, muscle is developed by use while the bad effects sometimes eventuating from distemper are caused by injury.
These points are important for an understanding of the subjects of particular interest to dog breeders, named the inborn and acquired faults, virtues, or diseases of their stock.
Inborn Traits Heritable ?Acquired Are Not!
It can thus be seen that the inborn and the acquired characteristics are in two separate classes.
The inborn is the result of the germ cells and is heritable, while the acquired affects the body cells, is not continuous in its life, and so cannot be transmitted.
Take as an example rickets, which is a disease of the bones (the body cells) due to a lack of vitamin D, calcium and phosphorus. It is, therefore, an acquired disease and is not transmitted, although, through faulty metabolism, the ability to assimilate the above mentioned essentials of proper nutrition might be.
On the other hand, the short tails which often appeared in the descendants of Nores v.d. Kriminalpolizei back in the nineteen twenties?German Shepherd Dogs were the result of an inherited trait due to genetic influence.
Contrasted to this, we find that the tails of several breeds of dogs, such as Fox Terriers and Dobermans, can be docked for generation after generation and, as this is a body cell injury and not inheritable, no change is made in the germ cells and succeeding generations of these dogs continue to come with long tails.
If the above principles are understood and applied to dog breeding, it will at once be seen that the main essentials of a good specimen are all dependent upon inborn characteristics and are therefore inherited.
By training, feeding, and other good care, they can be improved up to a certain PREDESTINED point, but beyond that it is impossible for them to be changed or improved.
This explains the characteristics, which are hereditary and thus transmissible, but when we come to the manner in which they are transmitted, in what degree they are transmitted, and how we can increase or eliminate them, the questions become much more difficult to answer.
Numerous scientists in the field of genetics have propounded various theories of animal breeding. As is well known, Mendel based his experiments on sweet peas, with which he explained the transference of characteristics from parent stock to succeeding generations. The characteristics of sweet peas are limited, but in dogs there are almost unlimited inherited factors and combinations of factors.
Gait for example, depends not only upon the conformation of the dog as regards his skeletal structure, but also upon the muscles working over it and the motor-nerve force stimulating them to action. The complexity of all these influencing factors is such that any attempt to use the Mendelian theory in the breeding of dogs is, for all practical purposes, out of the question.
This law, now generally accepted by all authorities on animal breeding, presupposes that the two parents contribute, between them, half of the inherited traits, each of them contributing one-quarter. The four grandparents contribute among them one-fourth of the inherited traits, or each of them one sixteenth. The eight great-grandparents contribute among them one-eighth, or each of them one sixty-fourth, and so on, the whole inheritance equaling the sum of the series.
It might be well to interject here a mention of how little influence any grandparent or great-grandparent has, when it appears no more than once in a pedigree, and also to indicate, to the proponents of continual out-crossings, how they are misleading both themselves and those who listen to them when they point to some notable dog in the third or fourth generation of their dog뭩 pedigree as being of particular value.
In order to apply Galton뭩 law with any degree of success. ~n animal breeder should be in possession of very accurate data as to the characteristics of the ancestors of the mating. pair, and this is often difficult to obtain. Furthermore, too few dog breeders are sufficiently interested in their breed뭩 improvement to take the trouble to look for such data before making their matings.
A further hindrance to the obtaining of ac curate information is that our conception o beauty and perfection is so changeable. Ideas regarding these attributes are comparative and our standards change continually, while perhaps not in actual wording, at least in interpretation by the judges.
These differences of opinion and selections by judges, some qualified and perhaps more who are not, lead to confusion. They make all but impossible any definite standard of beauty or utility.
While, scientifically speaking, neither Mendel뭩 nor Galton뭩 laws can be applied, practically speaking there are known results which work out very much in accordance with them.
Producing and Breeding Hybrids
For example, Mendel, in his experiments with sweet peas. bred together a tall and a short variety and got a hybrid generation. He bred these hybrids together and found he obtained 75 per cent tall plants and 25 per cent dwarf plants. The small plants were then bred together and produced nothing but small plants, but the 75 per cent of tall plants. when bred together, produced two kinds: (1) a mixed collection of tails and dwarfs, and (2) nothing but tails, the ratio of talls to dwarfs being as 2 to 1. In this way he learned that by breeding two hybrids (or intermediates) the result was 25 per cent tall, 50 per cent mixed, and 25 per cent dwarfs.
In all breeding it must be remembered that there are two types of characters, or factors, DOMINANT and RECESSIVE. In sweet peas, the talls were proven to be dominant and the dwarfs recessive, and each, when bred to its own kind, bred true; whereas the mixed when interbred produced the same formula of 25 per cent tall or pure dominants. ~0 per cent mixed, or impure dominants, and percent dwarfs, or pure recessives.
To set up the formula as simply as possible, we will take the letters PD to represent pure dominants (talls), PR to represent pure recessives (dwarfs), and ID to represent impure dominants (intermediates). The result of a union of two ID would work out as follows:
ID plus ID = 1PD, 2ID, 1PR.
That is, there would be one pure dominant to three others.
The Formula in Practice
If we consider some of our most prominent sires of the past whose records are available to us, as well as a few of the present dogs, we will find that occasionally there comes along a stud who seemingly sires outstanding specimens. as judged by their show wins. This is also true of bitches, as evidenced by Ch. Nyx of Long-Worth. for example.
I am mentioning the late Ch. Nyx here both because she is well known to every Shepherd breeder, and because she has undeniably had a greater influence for good on the breed than any other bitch, at least in comparatively modern times. Something of her record was given in an earlier installment and, while much more could be supplied, it would not serve my purpose here.
By the same token, I could use her grandson Ch. Vol of Long Worth, were I to choose a male for the purpose. Let us suppose that the parents of Nyx were both impure dominants and, for use in as simple a manner as possible, that the average litter is four in number. Then it is possible, even if not proven scientifically, that Nyx was the pure dominant, in various characteristics, in her litter.
While I found in actual breeding use that she was dominant in quite a number of characteristics, suppose we select one, rear angulation, to use here. (Although I am cognizant of the fact that rear angulation is not a simple genetic factor, but rather a combination of factors, it will nevertheless serve to well illustrate my point.)
Now let us set up some possible matings and their results. Taking the average litter as four, and figuring on three litters, there would be twelve puppies. Nyx, with dominant good rear angulation, if mated to a male with dominant good rear angulation, would produce all pure dominants. Mated to a sire with impure dominant rear angulation she would produce one-half pure dominants and one-half impure dominants. If mated to a pure recessive뾞 male with straight angulation in the rear as a pure recessive characteristic뾱he would produce all impure dominants.
These results may be tabulated as follows:
PD plus PD all PD
PD plus ID = one-half PD, one-half ID
PD plus PR all ID
Of the twelve puppies from the three sires, Nyx would produce six pure dominants and six impure dominants, but no pure recessives, as shown above.
Now take a bitch who is an impure dominant in this factor of rear angulation. which for demonstration purposes we have selected as the trait to use as an example, perhaps one of the above ID offspring.
The formula works out as follows:
ID plus PD = one-half impure dominants, one-half pure dominants
ID plus ID one-fourth pure dominants, one-half impure dominants. one-fourth pure recessives.
ID plus PR = one-half impure dominants, one-half pure recessives.
Again taking the average litter as four, there would be twelve pups out of this impure dominant bitch, sired by a pure dominant male, an impure dominant male, and a pure recessive male. There would be three pure dominants, six impure dominants, and three pure recessives in the offspring.
Thus, from a pure dominant female there would be in twelve puppies twice the number of good ones, or pure dominants for sufficient rear angulation, and no really poor ones. Again, as stated above. I used the bitch Nyx in these illustrations only because she is better known amongst the fancy than any other bitch of the breed, with a record of producing winners from every mating.
In the actual working out of these theories it is perhaps easier to use a sire. His ancestry is usually better known, and through being bred to many bitches his classification as to whether he is PD. ID. or PR in certain factors is more easily and quickly determined.
All of this seems more simple than it is often found to work out in actual practice but we all know that, in speaking of the prepotency of a sire or dam, we mean to what extent that animal is able to predominate in the blend resulting from matings with it. Its prepotency may vary and extend to any degree up to an entire inheritance.
Earlier in this article I mentioned Galton뭩 law and stated his theory that each ancestor contributed a certain proportion of the sum total in the offspring.
We will now take up what is sometimes termed "piling up the blood" of certain ancestors, or inbreeding and linebreeding, the terms used when the name of some ancestor appears several times in the pedigree. The exact term varies according to how many times the name occurs and where it occurs in the pedigree.
It stands to reason that if an ancestor뭩 name appears twice in a pedigree, especially if it is not far back in it, then his influence must be greatly increased; if three times, then it is of still greater value.
In matings where similar blood is united?where the pedigrees of each of the mating pair contain the name of a notable specimen of the breed뾵e often get results which are so fortunate as to cause us to speak of that particular mating as a "nick mating."
Suppose, for example, that a bitch has the blood of many sires but three of which we will designate as A. B and C. If she is mated to a stud who also has blood of different sires, but amongst them he also has stud C. as a close ancestor, we will say, then the resultant offspring will more likely inherit the characteristics of the C dog than of A or B, or any other dogs in the pedigree.
If these characteristics are desirable and what we are striving to breed into oar dogs, then the mating can be called a "nick mating." The Nyx mating to Ch. MarIo was an example, for this "D" litter containing six
One too often hears from exhibitors and breeders such remarks as, "I breed for the type that is winning, regardless of the Standard." This means to me that the speaker s future as a consistent?producer of high-quality dogs is most doubtful뾞nd that his real interest in the "game" is the superficial one of Champions (all that were ever shown out of the eight is represented in a large percentage of our modern type, and later-day, prepotent American bred German Shepherd Dogs.