IN-BREEDING.

New Zealand Illustrated Sporting & Dramatic Review, Volume XV, Issue 881, 24 January 1907, Page 5

IN-BREEDING.

In the course of an article on systematic breeding, an English writer takes up in-breeding, upon which subject he says:— With wild animals the same principle is always at work. Every animal has a fair chance of life, and if it cannot compete with its associates it goes under. The weakly zebra foal is deserted, or falls prey to the everwatching enemy. No weakling can ever have the chance of handing on its characteristics to future generations. Furthermore, the struggle of the males for supremacy insures that only the best out of these splendid animals obtains supremacy and procreates his like; and on the least suspicion of failing powers, he is ousted by his superior and thus the vitality of the species continues undiminished. Instead of constitutional weakness becoming inbred and hereditary, exactly the opposite takes place, and if wild animals inbreed to the extent which we believe they do, their grand health and strength is passed on as an hereditary attribute from one generation to another. The absence of selection is worst exemplified, of course, in the human family. The ever-in-creasing discoveries of science which

are continually finding new methods of combating disease and making endurable our ailments may be blessings to us, but any rate can hardly be called >a benefit for future generations. The very necessary prohibition of the marriage of near relations makes the general decline of the race slower than it would otherwise be; but, in spite of it, the survival to marry of the enormous army of the unsound in consequence of medical assistance is bound to tell in the long run, as i t does among other animals. We repeat we do not believe the closest in-breeding, even for an indefinite number of generations, would lead to any form of degeneration if only the constitutionally perfect were bred together. The question is, then, if we select for constitution, can we hope to maintain the characters of speed, action, weight, etc., as the case may be ? As matters at present stand, it hardly seems as if we could. The severe tests to which our racehorses are put is certainly some trial of constitutional merit, and if all breeders combined to breed from those individuals who stood the exigencies of a three or four years’ training, we should in a few years be in a fair way to possess a strain free from slur of delicacy which at present surrounds it. At present every speedy mare which fails to stand prolonged training, or which easily breaks down goes to the stud to become the dam of offspring which are bound to inherit a tendency, if nothing more, to their mother’s weakness. Inbreeding, the mating of these offspring with animals which perhaps possess a strain or two of the blood from which theii’ dam inherited her weakness, at once insures that the infirmity shall not be lost, and therefore we can truly say that in-breeding is, in a way, the cause of all the evils that are laid at its door, but not that it causes them. Under the circumstances breeders should go to the root of the matter, and turn their attention, above everything else, to the production of strong, healthy animals. In addition to the selection of healthy parents, there are other ways of doing this. One is to breed only from the fully mature, and from parents neither exclusively young nor exclusively old. Another is to breed under as natural conditions as possible, allowing an outdoor life to the mare and foals, and not permitting the birth of foals at unnatural seasons of the year because an extra race or two or some paltry prizes might be picked up by the advanced youngster. A third course is not to wean too early—in fact, if this process is conducted naturally, all the better for both. Of course, a liberal dietary during a foal’s first winter comes under the head of elementary stud management rather than within the province of this article, but. its importance with regard to the whole future life and development of a colt justifies one in alluding to it here.

There is an old and hackneyed saying that “ Like produces like.” So familiar is it -that we are sometimes apt to overlook its significance. It is proved by the experience of certain breeders of the smaller mammals that it is possible to breed successful prize-winners without recourse to close in-breeding at all. The observations of fanciers, it may be added, are often of much value by reason of the rapidity with which generation succeeds generation in small animals. Much more experience and valuable information are to be obtained than is the case with the slower breeding horses and cattle. We know more than one case of men who objected to consanguineous mating on principle, and who adopted the course of never breeding from near relatives. They found that by always buying the best, and by crossing the most perfect specimens together, the action of the above-mentioned saying was brought into force. That the animals were in reality related —that they were inbred in the back part of their pedigree—we have no doubt; at the same time the relationship was not near. It is extremely likely that the secret of the success lay in the fact that first-class specimens were bought regardless of cost, and that in consequence the females at any rate equalled, if they did not excel, the males in points of conformation. The importance of good females as a factor In successful breeding cannot be too. strongly insisted upon. Furthermore, to get the best results the mating together of animals with the same good points conduces to the transmission of these points to the offspring, and by in-breeding to them in subsequent generations they will be fixed, and will become potent characters in a strain.