Название | Cattle and Their Diseases |
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Автор произведения | Robert Jennings |
Жанр | Языкознание |
Серия | |
Издательство | Языкознание |
Год выпуска | 0 |
isbn | 4064066193423 |
But the udder is of special importance. It should be large in proportion to the size of the animal, and the skin thin, with soft, loose folds extending well back, capable of great distension when filled, but shrinking to a small compass when entirely empty. It must be free from lumps in every part, and provided with four teats set well apart, and of medium size. Nor is it less important to observe the milk-veins carefully. The principal ones under the belly should be large and prominent, and extend forward to the navel, losing themselves, apparently, in the very best milkers, in a large cavity in the flesh, into which the end of the finger can be inserted; but when the cow is not in full milk, the milk-vein, at other times very prominent, is not so distinctly traced; and hence, to judge of its size when the cow is dry, or nearly so, this vein may be pressed near its end, or at its entrance into the body, when it will immediately fill up to its full size. This vein does not convey the milk to the udder, as some suppose, but is the channel by which the blood returns; and its contents consist of the refuse of the secretion, or of what has not been taken up in forming milk. There are also veins in the udder, and the perineum, or the space above the udder, and between that and the buttocks, which it is of special importance to observe. These veins should be largely developed, and irregular or knotted, especially those of the udder. They are largest in great milkers.
The knotted veins of the perineum, extending from above downwards in a winding line, are not readily seen in young heifers, and are very difficult to find in poor cows, or those of only a medium quality. They are easily found in very good milkers, and if not at first apparent, they are made so by pressing upon them at the base of the perineum, when they swell up and send the blood back toward the vulva. They form a kind of thick network under the skin of the perineum, raising it up somewhat, in some cases near the vulva, in others nearer down and closer to the udder. It is important to look for these veins, as they often form a very important guide, and by some they would be considered as furnishing the surest indications of the milking qualities of the cow. Full development almost always shows an abundant secretion of milk; but they are far better developed after the cow has had two or three calves, when two or three years' milking has given full activity to the milky glands, and attracted a large flow of blood. The larger and more prominent these veins the better. It is needless to say that in observing them some regard should be had to the condition of the cow, the thickness of skin and fat by which they may be surrounded, and the general activity and food of the animal. Food calculated to stimulate the greatest flow of milk will naturally increase these veins, and give them more than usual prominence.
THE MILK-MIRROR.
The discovery of M. Guénon, of Bordeaux, in France—a man of remarkable practical sagacity, and a close observer of stock—consisted in the connection between the milking qualities of the cow and certain external marks on the udder, and on the space above it, called the perineum, extending to the buttocks. To these marks he gave the name of milk-mirror, or escutcheon, which consists in certain perceptible spots rising up from the udder in different directions, forms and sizes, on which the hair grows upward, whilst the hair on other parts of the body grows downward. The reduction of these marks into a system, explaining the value of particular forms and sizes of the milk-mirror, belongs exclusively to Guénon.
MILK-MIRROR [A.]
He divided the milk-mirror into eight classes, and each class into eight orders, making in all no less than sixty-four divisions, which he afterward increased by subdivisions, thus rendering the whole system complicated in the extreme, especially as he professed to be able to judge with accuracy, by means of the milk-mirror, not only of the exact quantity a cow would give, but also of the quality of the milk, and of the length of time it would continue. He endeavored to prove too much, and was, as a matter of consequence, frequently at fault himself.
Despite the strictures which have been passed upon Guénon's method of judging of cows, the best breeders and judges of stock concur in the opinion, as the result of their observations, that cows with the most perfectly developed milk-mirrors are, with rare exception, the best milkers of their breed; and that cows with small and slightly developed milk-mirrors are, in the majority of cases, bad milkers. There are, undoubtedly, cows with very small mirrors, which are, nevertheless, very fair in the yield of milk; and among those with middling quality of mirrors, instances of rather more than ordinary milkers often occur, while at the same time it is true that cases now and then are found where the very best marked and developed mirrors are found on very poor milkers. These apparent exceptions, however, are to be explained, in the large majority of cases, by causes outside of those which affect the appearance of the milk-mirror. It is, of course, impossible to estimate with mathematical accuracy either the quantity, quality, or duration of the milk, since it is affected by so many chance circumstances, which cannot always be known or estimated by even the most skillful judges; such, for example, as the food, the treatment, the temperament, accidental diseases, inflammation of the udder, premature calving, the climate and season, the manner in which she has been milked, and a thousand other things which interrupt or influence the flow of milk, without materially changing the size or shape of the milk-mirror. It has, indeed, been very justly observed that we often see cows equally well formed, with precisely the same milk-mirror, and kept in the same circumstances, yet giving neither equal quantities nor similar qualities of milk. Nor could it be otherwise; since the action of the organs depends, not merely on their size and form, but, to a great extent, on the general condition of each individual.
MILK-MIRROR [B.]
MILK-MIRROR [C.]
The different forms of milk-mirrors are represented by the shaded parts of cuts, lettered A, B, C, D; but it is necessary to premise that upon the cows themselves they are always partly concealed by the thighs, the udder, and the folds of the skin, which are not shown, and therefore they are not always so uniform in nature as they appear in the cuts.
MILK-MIRROR [D.]
Their size varies as the skin is more or less folded or stretched; while the cuts represent the skin as uniform or free from folds, but not stretched out. It is usually very easy to distinguish the milk-mirrors by the upward direction of the hair which forms them. They are sometimes marked by a line of bristly hair growing in the opposite direction, which surrounds them, forming a sort of outline by the upward and downward growing hair. Yet, when the hair is very fine and short, mixed with longer hairs, and the skin much folded, and the udder voluminous and pressed by the thighs, it is necessary, in order to distinguish the part enclosed between the udder and the legs, and examine the full size of the mirrors, to observe them attentively, and to place the legs wide apart, and to smooth out the skin, in order to avoid the folds.
The mirrors may also be observed by holding the back of the hand against the perineum, and drawing it from above downward, when the nails rubbing against the up-growing hair, make the parts covered by it very perceptible.
As the hair of the milk-mirror has not the same direction as the hair which surrounds it, it may often be distinguished by a difference in the shade reflected by it. It is then sufficient to place it properly to the light in order to see the difference in shade, and to make out the part covered by the upward-growing hair. Most frequently, however, the hair of the milk-mirror is thin and fine, and the color of the skin can easily be seen. If the eye alone is trusted, we