The Principles of Breeding / or, Glimpses at the Physiological Laws involved in the Reproduction and Improvement of Domestic Animals

by S. L. Goodale

We cannot say what might have been the original type of many of our domestic animals, for the inquiry would carry us beyond any record of history or tradition regarding it, but few doubt that all our varieties of the horse, the ox, the sheep and the dog, sprang each originally from a single type, and that the countless variations are due to causes connected with their domestication. Of those reclaimed within the period of memory may be named the turkey. This was unknown to the inhabitants of the old continent until discovered here in a wild state. Since then, having been domesticated and widely disseminated, it now offers varieties of wide departure from the original type, and which have been nurtured into self-sustaining breeds, distinguished from each other by the possession of peculiar characteristics.

Among what are usually reckoned the more active causes of variation may be named climate, food and habit.

Animals in cold climates are provided with a thicker covering of hair than in warmer ones. Indeed, it is said that in some of the tropical provinces of South America, there are cattle which have an extremely rare and fine fur in place of the ordinary pile of hair. Various other instances could be cited, if necessary, going to show that a beneficent Creator has implanted in many animals, to a certain extent, a power of accommodation to the circumstances and conditions amid which they are reared.

The supply of food, whether abundant or scanty, is one of the most active cases of variation known to be within the control of man. For illustration of its effect, let us suppose two pairs of twin calves, as nearly alike as possible, and let a male and a female from each pair be suckled by their mothers until they wean themselves, and be fed always after with plenty of the most nourishing food; and the others to be fed with skimmed milk, hay tea and gruel at first, to be put to grass at two months old, and subsequently fed on coarse and innutritious fodder. Let these be bred from separately, and the same style of treatment kept up, and not many generations would elapse before we had distinct varieties, or breeds, differing materially in size, temperament and time of coming to maturity.

Suppose other similar pairs, and one from each to be placed in the richest blue-grass pastures of Kentucky, or in the fertile valley of the Tees; always supplied with abundance of rich food, these live luxuriously, grow rapidly, increase in hight, bulk, thickness, every way, they early reach the full size which they are capable of attaining; having nothing to induce exertion, they become inactive, lazy, lethargic and fat. Being bred from, the progeny resemble the parents, "only more so." Each generation acquiring more firmly and fixedly the characteristics induced by their situation, these become hereditary, and we by and by have a breed exhibiting somewhat of the traits of the Teeswater or Durhams from which the improved Short-horns of the present day have been reared.

The others we will suppose to have been placed on the hill-sides of New England, or on the barren Isle of Jersey, or on the highlands of Scotland, or in the pastures of Devonshire. These being obliged to roam longer for a scantier repast grow more slowly, develop their capabilities in regard to size not only more slowly, but, perhaps, not fully at all—they become more active in temperament and habit, thinner and flatter in muscle. Their young cannot so soon shift for themselves and require more milk, and the dams yield it. Each generation in its turn becomes more completely and fully adapted to the circumstances amid which they are reared, and if bred indiscriminately with any thing and every thing else, we by and by have the common mixed cattle of New England, miscalled natives; or if kept more distinct, we have something approaching the Devon, the Ayrshire, or the Jersey breeds.

A due consideration of the natural effect of climate and food is a point worthy the special attention of the stock-husbandman. If the breeds employed be well adapted to the situation, and the capacity of the soil is such as to feed them fully, profit may be safely calculated upon. Animals are to be looked upon as machines for converting herbage into money. Now it costs a certain amount to keep up the motive power of any machine, and also to make good the wear and tear incident to its working; and in the case of animals it is only so much as is digested and assimilated, in addition to the amount thus required, which is converted into meat, milk or wool; so that the greater the proportion which the latter bears to the former, the greater will be the profit to be realized from keeping them.

There has been in New England generally a tendency to choose animals of large size, as large as can be had from any where, and if they possess symmetry and all other good qualities commensurate with the size, and if plenty of nutritious food can be supplied, there is an advantage gained by keeping such, for it costs less, other things being equal, to shelter and care for one animal than for two. But our pastures and meadows are not the richest to be found any where, and if we select such as require, in order to give the profit which they are capable of yielding, more or richer food than our farms can supply, or than we have the means to purchase, we must necessarily fail to reap as much profit as we might by the selection of such as could be easily fed upon home resources to the point of highest profit.

Whether the selection be of such as are either larger or smaller than suit our situation, they will, and equally in both cases, vary by degrees towards the fitting size or type for the locality in which they are kept, but there is this noteworthy difference, that if larger ones be brought in, they will not only diminish, but deteriorate, while if smaller be brought in, they will enlarge and improve.

The bestowal of food sufficient both in amount and quality to enable animals to develop all the excellencies inherent in them, and to obtain all the profit to be derived from them, is something very distinct from undue forcing or pampering. This process may produce wonderful animals to look at, but neither useful nor profitable ones, and there is danger of thus producing a most undesirable variation, for, as in plants, we find that forcing, pampering, high culture or whatever else it may be called, may be carried so far as to result in the production of double flowers, (an unnatural development,) and these accompanied with greater or less inability to perfect seed, so in animals, the same process may be carried far enough to produce sterility. Instances are not wanting, and particularly among the more recent improved Short-horns, of impotency among the males and of barrenness in the females, and in some cases where they have borne calves they have failed to secrete milk for their nourishment.[3] Impotency in bulls of various breeds has not unfrequently occurred from too high feeding, and especially if connected with lack of sufficient exercise.[4]