Читать книгу Cattle and Their Diseases - Robert Jennings - Страница 22

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The raising of cattle has now become a source of profit in many sections—to a greater extent, at least, than formerly—and it becomes a matter of great practical importance to our farmers to take the proper steps to improve them. Indeed, the questions—what are the best breeds, and what are the best crosses, and how shall I improve my stock—are now asked almost daily; and their practical solution would add many thousand dollars to the aggregate wealth of the farmers of the country, if they would all study their own interests.

The time is gradually passing away when the intelligent practical farmer will be willing to put his cows to any bull, simply because his services may be had for twenty-five cents; for, even if the progeny is to go to the butcher, the calf sired by a pure-bred bull—particularly of a race distinguished for fineness of bone, symmetry of form, and early maturity—will bring a much higher price at the same age than a calf sired by a scrub. Blood has a money value, which will, sooner or later, be generally appreciated.

The first and most important object of the farmer is to get the greatest return in money for his labor and his produce; and it is for his interest to obtain an animal—a calf, for example—that will yield the largest profit on the outlay. If a calf, for which the original outlay was five dollars, will bring at the same age and on the same keep more real net profit than another, the original outlay for which was not twenty-five cents, it is certainly for the farmer's interest to make the heavier original outlay and thus secure the superior animal. Setting all fancy aside, it is merely a question of dollars and cents; but one thing is certain—and that is, that no farmer can afford to keep poor stock. It eats as much, and requires nearly the same amount of care and attention, as stock of the best quality; while it is equally certain that stock of ever so good a quality, whether grade, native, or thorough-bred, will be sure to deteriorate and sink to the level of poor stock by neglect and want of proper attention.

How, then, is our stock to be improved? Not, certainly, by that indiscriminate crossing, with a total disregard of all well-established principles, which has thus far marked our efforts with foreign stock, and which is one prominent reason why so little improvement has been made in our dairies; nor by leaving all the results to chance, when, by a careful and judicious selection, they may be within our own control.

We want cattle for distinct purposes, as for milk, beef, or labor. In a large majority of cases—especially in the dairy districts, at least, comprising the Eastern and Middle States—the farmer cares more for the milking qualities of his cows, especially for the quantity they give, than for their fitness for grazing, or aptness to fatten. These latter points become more important in the Western and some of the Southern States, where much greater attention is paid to breeding and to feeding, and where comparatively slight attention is given to the productions of the dairy. A stock of cattle which would suit one farmer might be wholly unsuited to another, and in such particular case the breeder should have some special object in view, and select his animals with reference to it.

There are, however, some well-defined general principles that apply to breeding everywhere, and which, in many cases, are not thoroughly understood. To these attention will now be directed.

The first and most important of the laws to be considered in this connection is that of similarity. It is by virtue of this law that the peculiar characters, properties, and qualities of the parents—whether external or internal, good or bad, healthy or diseased—are transmitted to their offspring. This is one of the plainest and most certain of the laws of nature. The lesson which it teaches may be stated in five words:—Breed only from the best.

Judicious selection is indispensable to success in breeding, and this should have regard to every particular—general appearance, length of limb, shape of carcass, development of chest; in cattle, to the size, shape, and position of the udder, thickness of skin, touch, length and texture of hair, docility, and all those points which go to make up the desirable animal.

Not only should care be exercised to avoid structural defects, but especially to secure freedom from hereditary diseases; as both defects and diseases appear to be more easily transmissible than desirable qualities. There is, oftentimes, no obvious peculiarity of structure or appearance which suggests the possession of diseases or defects which are transmissible; and for this reason, special care and continued acquaintance are requisite in order to be assured of their absence in breeding animals; but such a tendency, although invisible or inappreciable to careless observers, must still, judging from its effects, have as real and certain an existence as any peculiarity of form or color.

In neat cattle, hereditary diseases do not usually show themselves at birth; and sometimes the tendency remains latent for many years, perhaps through one or two generations, and afterward breaks out with all its former severity. The diseases which are found hereditary in cattle are scrofula, consumption, dysentery, diarrhœa, rheumatism, and malignant tumors. As these animals are less exposed to the exciting causes of disease, and less liable to be overtasked or subjected to violent changes of temperature, or otherwise put in jeopardy, their diseases are not so numerous as those of the horse, and what they have are less violent, and generally of a chronic character.

With regard to hereditary diseases, it is eminently true that "an ounce of prevention is worth a pound of cure." As a general and almost invariable rule, animals possessing either defects or a tendency to disease, should not be employed for breeding. If, however, for special reasons it seems desirable to breed from one which has some slight defect of symmetry, or a faint tendency to disease—although for the latter it is doubtful whether the possession of any good qualities can fully compensate—it should be mated with one which excels in every respect in which it is itself deficient, and on no account with one which is near of kin to it.

There is another law, by which that of similarity is greatly modified—the law of Variation or divergence.

All animals possess a certain flexibility or pliancy of organization, which renders them capable of change to a greater or less extent. When in a state of nature, variations are comparatively slow and infrequent; but when in a state of domestication they occur much oftener and to a much greater extent. The greater variability in the latter case is doubtless owing, in some measure, to our domestic productions' being reared under conditions of life not so uniform as, and different from, those to which the parent species was exposed in a state of nature.

Among what are usually reckoned the more active causes of variation may be named climate, food, and habit. Animals in a cold climate 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. The supply of food, whether abundant or scanty, is one of the most efficient causes of variation known to be within the control of man. A due consideration of the natural effects of climate and food is a point worthy the careful attention of the stock-husbandman. If the breeds employed be well adapted to the situation, and the capacity of the soil be such as to feed them fully, profit may be safely anticipated. Animals are to be regarded as machines for converting herbage into money.

The bestowal of food sufficient, both in amount and quality, to enable animals to develop all the excellencies inherent in them, and yield all the profit of which they are capable, is something quite distinct from undue forcing of pampering. The latter 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, since in animals the process may be carried far enough to produce barrenness. Instances are not wanting, particularly among the more recent improved short-horns, of impotency among the males and of barrenness among the females; and in some cases where the latter have borne calves, they have failed to secrete sufficient milk for their nourishment. Impotency in bulls of various breeds has, in many instances, occurred from too high feeding, especially when connected with a lack of sufficient exercise. A working bull, though perhaps not so pleasing to the eye as a fat one, is a surer stock-getter; and his progeny is more likely to inherit full health and vigor.

Habit has a decided influence toward producing variations. We find in domestic animals that use—or the demand created by habit—is met by a development or change in the organization adapted to the requirement. For instance, with cows in a state of nature, or where required only to suckle their young, the supply of milk is barely fitted to the requirement. If more is desired, and the milk is drawn completely and regularly, the yield is increased and continued longer. By keeping up the demand there is induced, in the next generation, a greater development of the secreting organs, and more milk is given. By continuing the practice, by furnishing the needful conditions of suitable food and the like, and by selecting in each generation those animals showing the greatest tendency toward milk, a breed specially adapted for the dairy may be established. It is just by this mode that the Ayrshires have, within the past century, been brought to be what they are—a breed giving more good milk upon a certain amount of food than any other.