Heredity And Animal Breeding
( Originally Published 1912 )
Unusually successful breeders are looked upon by persons not conversant with higher aspects of animal breeding as being possessed of some carefully guarded secrets or rules of mating that give them unusual advantages in their work. Anyone not familiar with the art of breeding cannot appreciate the necessity and efficacy of extended and studious observation combined with careful experience. Obviously there is nothing about an animal's individuality or breeding powers that may not be learned as readily by one person as by another, but the difference lies in the significance of the external indications to variously equipped men, and in their courage and willingness to act upon what they have learned to read in the animals scrutinized. Again it is apparent that by far the chief feature of breeding is in the selection of animals for mating.
To formulate any rules or guides from the work and instruction of even the most successful breeders is a very confusing task. Many such men have seriously discussed the teachings of their experience in regard to the relative influence upon the progeny of the male and female parents. In some instances we are recommended to select a certain type or class of females to mate with a specified type of male; in others emphasis is laid on ancestors of one sex almost to the exclusion of the other sex. Practically all emphasize the necessity of a good line of ancestry, though just what constitutes such and what weight it should be given in comparison with individual make-up is impossible of clear expression.
A long, careful, practical apprenticeship to the operations of our more capable breeders will bring a person of ordinary natural qualities for the work into an intimacy with the aims and guiding principles of the profession that will remove the seeming vagueness of the precepts of even the best followers of the art. At the same time such a person must still be conscious of a superficiality of his knowledge of the laws and forces with which he deals. It has been said that while the practices of the breeders show much of uniformity in their estimation and application of the principles involved, yet their precepts lack entirely the clearness and similarity of their examples. At first sight this is somewhat discouraging to the student or beginner, and it is the aim of these pages to first look into some facts and conditions that obtain in all breeding and which may constitute a basis for later discussion of principles that govern in all breeding operations.
Both precept and example of all good breeders show a uniformity and fundamental reliance upon the principle commonly expressed in the phrase, "Like begets like." Robert Bakewell could say no more to the eager solicitors of his secret than "Breed the best to the best." A hundred years later the sage of Sittyton with as much frankness and definiteness as was possible to put into words assured those who clamored to know the reason of the unusual fleshing of his Short-horns that "thick-fleshed cattle breed thick-fleshed cattle."
Thé most helpful discussion of Bakewell's ideas that is now available is printed by Youatt and is herewith quoted :
"Having remarked that domestic animals in general produced others possessing qualities similar to their own, he conceived the idea that he had only to select the most valuable breeds, such as promised to return the greatest emolument to the breeder, and that he should then be able, by careful attention to progressive improvement, to produce a breed whence he could derive a maximum of advantage.
"Under the influence of this excellent notion, he made excursions into different parts of England, in order to inspect the different breeds, and to select those that were best adapted to his purpose, and the most valuable of their kind, and his residence and his early habits disposed him to give the preference to the Long-horn cattle.
"We have no account of the precise principles which guided him, nor of the motives that influenced him in the various selections which he made ; but Mr. Marshall, who says that he `was repeatedly favored with opportunities of making observations on Mr. Bakewell's practice, and with liberal communications from him on all rural subjects,' gives us some clue. He tells us, however, that `it is not his intention to deal out Mr. Bakewell's private opinions, or even to attempt a recital of his particular practice.' Mr. Marshall was doubtless influenced by an honorable motive in withholding so much that would have been highly valuable; and we can only regret that he was so situated as to have this motive pressing on his mind.
"He speaks of the general principles of breeding, and when he does this in connection with the name of Bake-well, we shall not be very wrong in concluding that these were the principles by which that great agriculturist was influenced.
" `The most general principle,' he says (we are referring to his `Economy of the Midland Counties,' vol. I, p. 297), `is beauty of form. It is observable, however, that this principle was more closely attended to at the outset of improve ment (under an idea in some degree falsely grounded, that the beauty of form and utility are inseparable) than at present, when men who have long been conversant in practice make a distinction between a `useful sort' and a sort which is merely `handsome.'
"The next principle attended to is a proportion of parts, or what may be called utility of form in distinction from beauty of form; thus the parts which are deemed offal, or which bear an inferior price at market, should be small in proportion to the better parts.
"A third principle of improvement is the texture of the muscular parts, or what is termed flesh, a quality of live stock which, familiar as it may long have been to the butcher and the consumer, had not been sufficiently attended to by breeders, whatever it might have been to graziers. This principle involved the fact that the grain of meat depended wholly on the breed, and not, as has been before considered, on the size of the animal. But the principle which engrossed the greatest share of attention, and which above all others is entitled to the graziers' attention, is fattening quality, or a natural propensity to acquire a state of fatness at an early age, and when in full keep, in a short space of time, a quality which is clearly found to be hereditary.
"Therefore, in Bakewell's opinion, everything depended on breed, and the beauty and utility of the form, the quality of the flesh and the propensity to fatten were, in the offspring, the natural consequence of similar qualities in the parents. His whole attention was centered on these four points ; and he never forgot that they were compatible with each other, and might be occasionally found in the same individual.
"Improvement had hitherto been attempted to be produced by selecting females from the native stock of the country, and crossing them with males of an alien breed. Mr. Bakewell's good sense led him to imagine that the object might be better accomplished by uniting the superior branches of the same breed, than by any mixture of foreign ones.
"On this new and judicious principle he started. He purchased two Long-horn heifers from Mr. Webster, and he procured a promising Long-horn bull from Mr. Westmoreland. To these and their progeny he confined him-self, coupling them as he thought he could best increase or establish some excellent point, or speedily and effectually remove a faulty one.
"Many years did not pass before his stock was un-rivalled for the roundness of its form, the smallness of its bone and its aptitude to acquire external fat; while they were small consumers of food in proportion to their size; but at the same time, their qualities as milkers were very considerably lessened."
Youatt refers to one of Bakewell's bulls to which a few cows were brought at 5 guineas each. He also quotes Marshall regarding Bakewell in the words :
"He likewise gives a curious account of Mr. Bake-well's hall. `The separate joints and points of each of the more celebrated of his cattle were preserved in pickle, or hung up side by side, showing the thickness of the flesh and external fat on each, and the smallness of the offal. There were also skeletons of the different breeds, that they might be compared with each other, and the comparative difference marked.' "
The following is also taken from Youatt:
"The practice of letting bulls originated in this district, and chiefly with Mr. Bakewell, and was generally adopted. The bulls were sent out in April, or the be-ginning of May, and were returned in August. The prices varied from Io to 50 or 6o pounds ; but in one case, * * * a bull was let at 80 guineas a season. Further evidence of the estimation in which the Bakewell stock was held is shown in his letting three rams in 1787 for 1,200 guineas."
It is commonly written that Bakewell was very reticent by nature and guarded very closely the "secrets of his operations." It seems more just to consider that to the inquirers of his time the process of selection seemed inadequate, and they found it easier to suppose that there was some carefully guarded factor the possession of which would make them equally successful.
In dealing with the relation of offspring and parents we are in touch with the force commonly spoken of as heredity. Manifestly, the desideratum of the breeding profession is the highest possible measure of control over the force of heredity. The past decade has been marked by unusual progress toward a more comprehensive understanding of the various aspects of heredity. Discoveries have opened new avenues of investigation; previously puzzling phenomena have been rendered possible of explanation, and there exists a somewhat confident air that in the not remote future the breeding of animals will be placed on a plane of greater definiteness and less uncertainty than it now occupies. To study heredity and its newer and scientific aspects as applied to the former and present conceptions of breeding is the object of the succeeding chapters.
The term heredity is most commonly defined as the tendency of the offspring to resemble the parent form. The same thought has been expressed in "Like begets like." We are reminded on every hand in both plant and animal life that like begets like in a general way so far as species or variety is concerned, and in the main also individuality of offspring is close to that of parent. In an exact sense, however, no animal is a counterpart of either parent. Total merit or separate points as often vary away from as toward what we desire. The making of our breeds has consisted no less in the elimination of the undesirable than in the perpetuation and combination of the better features of such animals as have been regarded as approaching more nearly to the ideal of usefulness and value for the purpose for which bred. Manifestly heredity and its study is as much concerned with a consideration of the minor departures from resemblance of offspring to parental type as with the likenesses.
The idea of heredity finds expression in our common words "heritage" and "inheritance," as implying the transfer of title or possession from one generation to another. The proper study of heredity in animals, however, must not fail to recognize that the young animal's heritage is complete at its birth; no subsequent dependence or connection with either parent for nourishment or protection can be considered as in any sense a hereditary relation ; in fact, it will later be shown that hereditary impress was fully conveyed at a much earlier period, namely, at conception.
The confusion resulting from the attempt to apply the truth of "Like begets like" in exact or minute sense arises from the necessity of considering every animal in relation to two parents. The physiology of the reproductive processes having to do with the making of a new animal are well understood and sufficiently easy of explanation to repay careful study by one who would familiarize himself with the fundamentals of the breeder's work. The relation of each of the parents to their progeny and the real ultimate origin is made clear by an understanding of the arrangement and functions of the reproductive organs, more particularly in the female.