Some of the leading scientific principles of animal husbandry are readily illustrated by showing their application to a dairy farm. To conduct a dairy successfully the dairyman must give careful attention to the following particulars: 1. Careful selection of his herd. 2. The construction and maintenance of suitable stables and other buildings necessary to the work. 3. Providing the right sort of pasturage. 4. Providing the right sort of feed in addition to pasturage. 5. Facilities for the care and marketing of the dairy products. Neglect of any one of these points is liable to lead to failure in the enterprise. The Herd. The cows should be selected with reference to the main purpose for which the dairy is conducted. If the dairy is to supply milk for city markets, the cows should be chosen with due regard to the quantity of milk which they produce. If the dairy is devoted to supplying the market with butter, more regard must be paid to the quantity of butter fat in the milk than in the former case. Experienced dairymen are good judges of cows and seldom make mistakes in the selection of herds. For the benefit of those of less experience the following points, taken from Brook's Animal Husbandry, are given: HEAD--Small, lean and bony, with large muzzle and mouth. The nose and face should be free from fleshiness. EYE--Full, large, lively in expression, but at the same time mild, clear and bright. The whole expression of the face and eye should be motherly. FOREHEAD--May be either straight or dishing, but the latter gives a more well-bred appearance. EAR--Thin, large, active, and for most breeds should be of an orange color within. NECK--Should be rather thin, especially near the head, and long. It should be free in most breeds from loose, pendent skin. HORNS--Should be of moderate size. SHOULDERS--The animal at the shoulders may be from two to four inches lower than at the hips. The shoulders themselves should be thin, especially at the top, lean and bony. CHEST--Should be deep, that is, it should have a large measurement from top to bottom. It is less broad and roomy than in beef breeds. The section through the animal behind the shoulders should have an elliptical outline. Too great thinness behind the shoulders is, however, a mark of weak constitution. BACK--Should be rather long and rugged. The vertebrae of the backbone should be rather wide apart so that the fingers may be pressed down between the points in the ridge of the back. This is only one feature of the general looseness of structure which is looked for in the dairy type, as contrasted with the close, compact structure which is desirable in the beef type. LOINS--Should be fairly broad, the hip bones rather high and well apart. The bones, moreover, are often rather farther forward than in the beef type. This gives a long and strong hind quarter. THIGHS--The thighs should be thin, especially on the inside, in order to give room for a large udder. FLANK--The flank is well up, and rather thin. LEGS--The legs should be rather short and the hind legs may be rather crooked. The bones of the legs should be moderately fine. The forelegs are comparatively near together, the hind legs wide apart. TAIL--The tail should be long and fine, with a long switch. A long tail is believed to indicate that the vertebrae of the backbone are somewhat loosely connected, which, as has been pointed out, is considered highly desirable. THE GENERAL OUTLINE--When looked at from the side, the general outline should be that of a wedge, the upper line, or line of the backbone, and the lower line, or the line of the belly, approaching each other from behind. When looked at from behind or from above, the animal should also present a wedge shape, the lines of the wedge approaching each other from rear to front. The dairy cow, therefore, shows a double wedge. The ribs, to harmonize with this general wedge shape, are rather flat immediately behind the shoulders. At this point they do not spring out very widely, but toward the posterior part of the animal the ribs spring out from the backbone more and more broadly in order to give room for large internal organs "for a big workshop." THE UDDER--The udder should not be very pendent, but should obtain capacity by breadth, being wide from side to side, extending well forward, well backward also, and high up between the thighs. It should be broadly and firmly attached to the abdomen. The skin of the udder should be thin and delicate. The udder should be well filled out at the bottom between the teats, and the latter should be wide apart, squarely placed, and of good size. A daily record of each cow should be kept and those that do not reach the required standard should be sold or fattened for beef and their places taken by others. Only the calves from the best milkers should be retained for future additions to the herd. In this way the strain of the herd will be strengthened from year to year. The record should enlighten the dairyman concerning two points: the average daily quantity of milk given by each cow and the length of time from calving before the quantity of milk begins to diminish. The most profitable animals are good milkers for a long time. They may not produce such large quantities of milk while fresh as some others, but their record for six months or a year shows them to be far more profitable. It costs no more to keep a good cow than a poor one, and the first is kept at a profit, while the second is kept at a loss. The next thing necessary is a milk test which will show the amount of butter fat as well as the quantity of cream. This test should be made by an expert in a creamery or butter factory if possible, because in these places the necessary apparatus is at hand and an expert is usually in charge. If, however, the farmer is so situated that he must make his own test for milk, by sending to his experiment station for directions, he will receive such assistance and guidance as will enable him to make the test successfully. The Stable. Milk can be produced only from healthy cows, and in most regions where dairying is carried on, proper housing of the herd is the important factor in preserving the health of the animals. Disease, especially tuberculosis, is frequently contracted because the stable is poorly ventilated and because it is kept in a filthy condition. The stable should be well-ventilated and well-lighted. The walls should be kept free from dust and should be frequently whitewashed. Above all, the floors should be kept free from filth and plenty of fresh, clean litter should be spread daily. Open feed troughs and partitions made of piping or iron railing, which will not collect the dust, are the most desirable. The yard and grounds about the barn should also be free from weeds, manure and rubbish. Feed. Fresh grass is the most desirable feed for milch cows, but suitable pasturage for a large herd requires so much land that some other source of food supply available all the year is necessary. During the months when pastures are not in grass, the cows must be fed entirely from this other source. The right sort of ration must be determined and the most economic means of supplying it be provided. Many farmers use ensilage, or silage, as it is commonly called. The Silo. The silo has become a fixed part of the equipment of nearly all dairy farms. It enables the farmer to preserve a larger quantity of fodder than is possible by any other system of preservation known. Moreover, it preserves the fodder in nearly as natural a state as possible. While a good silo is somewhat expensive, on the other hand it soon pays for the outlay by the beneficial results which it yields. Silos are constructed of various materials. Doubtless those built of concrete are the best, as they are certainly the most durable. On the other hand, they are the most expensive and beyond the reach of many farmers who can afford to build only a wooden structure. For this reason stave silos are more commonly seen than any others. Various forms of these silos are in use, and a farmer desiring to construct one should consult firms which make a business of putting up buildings of this sort. While by doing work himself the farmer might save a little expense at the outset, yet the risk of making an imperfect structure is too great to warrant attempting to save the slight difference in expense. A cylindrical silo 20 feet in diameter and 20 feet high will contain 105 tons of silage and one of the same diameter 25 feet high and 25 feet in diameter will contain 224 tons. These figures enable a farmer to judge quite accurately as to the size of a silo which he wishes to build, and the work should be done by one experienced in constructing buildings of this sort. All things being equal, the cylindrical silo is the best. It contains no angles, it is more easily kept tight and is easily cleaned when emptied. Moreover, the cylindrical silo is the strongest from for a structure of this sort, and it is not easily pressed out of shape by the pressure from within. In locating the silo the farmer should carefully consider two things: first, convenience in handling the silage, which must be done at least twice a day; and secondly, the position of the silo with reference to the stable, so that odors arising from it will not penetrate the stable, at least during milking time, since milk readily absorbs odors of this sort. The silo should be as near the stable as possible without danger of contaminating the milk. If the cows are fed after milking time and the stable is thoroughly aired before milking time, there is but little danger from these odors. The bottom of the silo should be cement or plank, but cement is preferable, since a plank bottom causes a loss of five or six inches of the silage next to it. The structure should be airtight, but the roof should provide ample ventilation. With these points in view, the farmer desiring to construct a silo knows about what to require of the builders. Connected with this article is an illustration of a silo of a very satisfactory type. Various crops are suitable for silage, but experiment has shown that corn is the most desirable. Alfalfa and clover are also used to good advantage. Experiments have shown that the best results are obtained from corn silage when the crop is cut just as the ears are beginning to glaze. As the corn is cut in the field, it is hauled to the ensilage cutter, which cuts it into pieces about an inch in length, using the stalks and ears without separation. As the cut silage leaves the machine, it is carried by an endless belt containing buckets, or by a blower, to the silo. If the plant is dry it should be thoroughly wet after leaving the cutter, before it is packed. Otherwise it soon becomes mildewed. In case of dry crops it is the practice to run a stream of water over the silage as it leaves the cutter. The water tends to make the mass in the silo air-tight, and thus prevent fermentation and decay. When the silo is filled, the ensilage should be covered by some preparation which will exclude the air. Local conditions determine what can be used to the best advantage. The doors in the side of the silo should, of course, be kept closed until the contents have been lowered to each succeeding door. Silage protected from the air will be kept fresh and succulent through the winter, and it is practically as nourishing and healthful as the grass obtained in the average pasture. The silo combines the advantages of storing a large amount of feed in a small space and of keeping it in its natural state until used. Moreover, by this means of storage, the farmer can raise upon a few acres fodder, which, if raised under ordinary conditions, would require many times the acreage, and, in addition to this, the silage is much better adapted to the purpose of feeding milk cows than any other sort of dairy food. Milk. Healthy cows, suitable feed and cleanliness are essential to the production of good milk. The first two of these conditions we have already discussed. The third is equally important. No farm product is so sensitive to its surroundings as freshly drawn milk. It absorbs particles from the air and odors from any substances in close proximity to it, or from the atmosphere impregnated with the odor of such substances. Moreover, the smallest particles of dirt may contain germs which multiply very rapidly and in a short time render the milk unfit for use, either because it is disagreeable to the palate or because it contains germs which will convey disease to the system. Under cleanliness three things should be considered. The first of these is the condition of the stable. Before milking, the air in the stable should be changed, so that it will be pure and fresh. Sweeping or littering the cows before milking should be avoided, because these operations raise dust which it liable to contaminate the milk. The second point pertains to drawing the milk. The milkers should wear clean clothing and have their hands clean and dry. Previous to milking, the udders and flanks of the cow should be wiped with a damp cloth, so as to remove any particles of dirt or dust which might fall into the pails. Pails with small tops should be used. Those with the tops partially covered are preferred. The old-fashioned wide-top pail should in all cases be avoided. As soon as the milk is drawn it should be removed from the stable, strained and cooled. However, if the milk is to be used at once, or in a few hours, the cooling is not essential. In small dairies milk is usually strained into cans which are placed in cold water. The temperature should be reduced to 40deg, or at least 45 deg. If the cans are covered so that the air is excluded, under these conditions milk will keep sweet from 24 to 36 hours, sometimes longer. Milk designed for butter and cheese should be taken to the creamery at the earliest opportunity, for there suitable facilities are provided for storing it under proper conditions and temperature. Milk designed for shipment to a city should be stored in receptacles that are kept in ice. All utensils employed in the reception or storage of milk should be thoroughly cleaned immediately after using, and scalded with boiling water, or, what is better, placed in a vat and steamed for several minutes. This will kill all germs that may adhere to the surface. Sour milk is caused by the growth of bacteria which convert the sugar in the milk into acid. These bacteria are not active at a low temperature. Therefore warm milk sours much more quickly than cold. The following illustration, taken from "Farmers' Bulletin No. 63," United States Department of Agriculture, shows the contents of pure milk freshly drawn, and of milk which has stood in a warm room in a dirty dish for a few hours. Good milk contains about 87% water, 3.6% fat and 4.8% sugar, besides a number of other ingredients. Under normal conditions it is the most healthful and perfect food provided. However, it does not contain sufficient nutriment to supply the demands of the adult human system, but it is an important factor in that supply. Milk should never be considered as a beverage, and when it forms a part of one's diet, the other portions of the diet should be regulated in accordance with the kind and amount of nutriment which the milk contains. See Bacteria; Animal Husbandry; Milk.