CATTLE AND THEIR DISEASES TEXT

of fifteen months, that shown in the next, where the corner teeth are not more than half the original size, and the centre ones still smaller. [Illustration: TWO YEARS PAST.] The permanent teeth are now rapidly growing, and preparing to take the place of the milk-teeth, which are gradually absorbed till they disappear, or are pushed out to give place to the two permanent central incisors, which at a year and a half will generally present the appearance indicated in the cut, which shows the internal structure of the lower jaw at this time, with the cells of the teeth, the two central ones protruding into the mouth, the next two pushing up, but not quite grown to the surface, with the third pair just perceptible. These changes require time; and at two years past the jaw will usually appear as in the cut, where four of the permanent central incisors are seen. After this, the other milk-teeth decrease rapidly, but are slow to disappear; and at three years old, the third pair of permanent teeth are but formed, as represented in the cut; and at four years the last pair of incisors will be up, as in the cut of that age; but the outside ones are not yet fully grown, and the beast can hardly be said to be full-mouthed till the age of five years. But before this age, or at the age of four years, the two inner pairs of permanent teeth are beginning to wear at the edges, as shown in the cut; while at five years old the whole set becomes somewhat worn down at the top, and on the two centre ones a darker line appears in the middle, along a line of harder bone, as appears in the appropriate cut. [Illustration: THREE YEARS PAST.] [Illustration: FOUR YEARS PAST.] [Illustration: FIVE YEARS PAST.] [Illustration: TEN YEARS PAST.] Now will come a year or two, and sometimes three, when the teeth do not so clearly indicate the exact age, and the judgment must be guided by the extent to which the dark middle lines are worn. This will depend somewhat upon the exposure and feeding of the animal; but at seven years these lines extend over all the teeth. At eight years, another change begins, which cannot be mistaken. A kind of absorption begins with the two central incisors--slow at first, but perceptible--and these two teeth become smaller than the rest, while the dark lines are worn into one in all but the corner teeth, till, at ten years, four of the central incisors have become smaller in size, with a smaller and fainter mark, as indicated in the proper cut. At eleven, the six inner teeth are smaller than the corner ones; and at twelve, all become smaller than they were, while the dark lines are nearly gone, except in the corner teeth, and the inner edge is worn to the gum. POINTS OF A GOOD COW. After satisfaction is afforded touching the age of a cow, she should be examined with reference to her soundness of constitution. A good constitution is indicated by large lungs, which are found in a deep, broad, and prominent chest, broad and well-spread ribs, a respiration somewhat slow and regular, a good appetite, and if in milk a strong inclination to drink, which a large secretion of milk almost invariably stimulates. In such a cow the digestive organs are active and energetic, and they make an abundance of good blood, which in turn stimulates the activity of the nervous system, and furnishes the milky glands with the means of abundant secretion. Such a cow, when dry, readily takes on fat. When activity of the milk-glands is found united with close ribs, small and feeble lungs, and a slow appetite, often attended by great thirst, the cow will generally possess only a weak and feeble constitution; and if the milk is plentiful, it will generally be of bad quality, while the animal, if she does not die of diseased lungs, will not readily take on fat, when dry and fed. [Illustration: A GOOD MILCH COW.] In order to have no superfluous flesh, the cow should have a small, clean, and rather long head, tapering toward the muzzle. A cow with a large, coarse head will seldom fatten readily, or give a large quantity of milk. A coarse head increases the proportion of weight of the least valuable parts, while it is a sure indication that the whole bony structure is too heavy. The mouth should be large and broad; the eye bright and sparkling, but of a peculiar placidness of expression, with no indication of wildness, but rather a mild and feminine look. These points will indicate gentleness of disposition. Such cows seem to like to be milked, are fond of being caressed, and often return caresses. The horns should be small, short, tapering, yellowish, and glistening. The neck should be small, thin, and tapering toward the head, but thickening when it approaches the shoulder; the dewlaps small. The fore quarters should be rather small when compared with the hind quarters. The form of the barrel will be large, and each rib should project further than the preceding one, up to the loins. She should be well formed across the hips and in the rump. The spine or back-bone should be straight and long, rather loosely hung, or open along the middle part, the result of the distance between the dorsal vertebrae, which sometimes causes a slight depression, or sway back. By some good judges, this mark is regarded as of great importance, especially when the bones of the hind quarters are also rather loosely put together, leaving the rump of great width and the pelvis large, and the organs and milk-vessels lodged in the cavities largely developed. The skin over the rump should be loose and flexible. This point is of great importance; and as, when the cow is in low condition or very poor, it will appear somewhat harder and closer than it otherwise would, some practice and close observation are required to judge well of this mark. The skin, indeed, all over the body, should be soft and mellow to the touch, with soft and glossy hair. The tail, if thick at the setting on, should taper and be fine below. 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. Guenon, 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 Guenon. [Illustration: 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 Guenon'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. [Illustration: MILK-MIRROR [B.]] [Illustration: 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. [Illustration: 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 shall often be deceived. [Illustration: MILK-MIRROR [E.]] In some countries cattle-dealers shave the back part of the cow. Just after this operation the mirrors can neither be seen nor felt; but this inconvenience ceases in a few days. It may be added that the shaving--designed, as the dealers say, to beautify the cow--is generally intended simply to destroy the milk-mirror, and to deprive buyers of one means of judging of the milking qualities of the cows. It is unnecessary to add that the cows most carefully shaven are those which are badly marked, and that it is prudent to take it for granted that cows so shorn are bad milkers. Milk-mirrors vary in position, extent, and the figure which they represent. They may be divided according to their position, into mirrors or escutcheons, properly so called, or into lower and upper tufts, or escutcheons. The latter are very small in comparison with the former, and are situated in close proximity to the vulva, as seen at 1, in cut E. They are very common on cows of bad milking races, but are very rarely seen on the best milch cows. They consist of one or two ovals, or small bands of up-growing hair, and serve to indicate the continuance of the flow of milk. The period is short, in proportion as the tufts are large. They must not be confounded with the escutcheon proper, which is often extended up to the vulva. They are separated from it by bands of hair, more or less large, as in cut marked F. [Illustration: MILK-MIRROR [F.]] Milk-mirrors are sometimes symmetrical, and sometimes without symmetry. When there is a great difference in the extent of the two halves, it almost always happens that the teats on the side where the mirror is best developed give more milk than those of the opposite side. The left half of the mirror, it may be remarked, is almost always the largest; and so, when the perinean part is folded into a square, it is on this side of the body that it unfolds. Of three thousand cows in Denmark, but a single one was found, whose escutcheon varied even a little from this rule. The mirrors having a value in proportion to the space which they occupy, it is of great importance to attend to all the rows of down-growing hairs, which diminish the extent of surface, whether these tufts are in the midst of the mirror, or form indentations on its edges. These indentations, concealed in part by the folds of the skin, are sometimes seen with difficulty; but it is important to take them into account, since in a great many cows they materially lessen the size of the mirror. Cows are often found, whose milk-mirrors at first sight appear very large, but which are only medium milkers; and it will usually be found that lateral indentations greatly diminish the surface of up-growing hair. Many errors are committed in estimating the value of such cows, from a want of attention to the real extent of the mirror. All the interruptions in the surface of the mirror indicate a diminution in the quantity of the milk, with the exception, however, of small oval or elliptical plates which are found in the mirror, on the back part of the udders of the best cows, as represented in the cut already given, marked A. These ovals have a peculiar tint, which is occasioned by the downward direction of the hair which forms them. In the best cows these ovals exist with the lower mirrors very well developed, as represented in the cut just named. In short, it should be stated that, in order to determine the extent and significance of a mirror, it is necessary to consider the state of the perineum as to fat, and that of the fullness of the udder. In a fat cow, with an inflated udder, the mirror would appear larger than it really is; whilst in a lean cow, with a loose and wrinkled udder, it appears smaller. Fat will cover faults--a fact to be borne in mind when selecting a cow. In bulls, the mirrors present the same peculiarities as in cows; but they are less varied in their form, and especially much less in size. In calves, the mirrors show the shapes which they are afterwards to have, only they are more contracted, because the parts which they cover are but slightly developed. They are easily seen after birth; but the hair which then covers them is long, coarse, and stiff; and when this hair falls off, the calf's mirror will resemble that of the cow, but will be of less size. With calves, however, it should be stated, in addition, that the milk-mirrors are more distinctly recognized on those from cows that are well kept, and that they will generally be fully developed at two years old. Some changes take place in the course of years, but the outlines of the mirror appear prominent at the time of advanced pregnancy, or, in the case of cows giving milk, at the times when the udder is more distended with milk than at others. M. Mayne, who has explained and simplified the method of M. Guenon, divides cows, according to the quantity which they give, into four classes: first, the very good; second, the good; third, the medium; and fourth, the bad. In the FIRST class he places cows, both parts of whose milk mirror, the mammary--the tuft situated on the udder, the legs and the thighs--and the perinean--that on the perineum, extending sometimes more or less out upon the thighs--are large, continuous, and uniform, covering at least a great part of the perineum, the udder, the inner surface of the thighs, and extending more or less out upon the legs, as in cut A, with no interruptions, or, if any, small ones, oval in form, and situated on the posterior face of the udder. [Illustration: MILK-MIRROR [G.]] Such mirrors are found on most very good cows, but may also be found on cows which can scarcely be called good, and which should be ranked in the next class. But cows, whether having very well developed mirrors or