ment unfavorably, seems reasonable to infer. I give below not only the food, but the proportion of butter to milk: Cow. Feed. Proportion. 1 lb. : 23.23 lbs. 1 lb.: 23.27 lbs. = = 1 lb.: 17.77 lbs. No. 1. Pasture, and qt. of oil meal, about 2 to 3 qts. shorts No. 2. Pasture, and 3 qts. of oil meal, 3 qts shorts, 1 qt. oats No. 3. Pasture, and qt. of oil meal, about 2 to 3 qts. shorts Milk of different cows, but of the same breed and herd, measurements taken at different times, and under varying conditions. The sequences are not, therefore, as regular as they otherwise might be. By collating some measurements which were taken from the lower layer of cream, and not incorporated in the above table, we have additional illustrations: We may now proceed to consider some of the consequences which result, in practice, from these facts. It is well known that the yield of butter from cows varies in amount from day to day, from causes which have not yet been accurately determined, but may be formulated in the terms food and circumstance. Mr. Blanchard, quoted in the National Live Stock Journal for 1872, p. 205, in an address before the "Butter Makers' Association," states that a dairy which one day will make one pound of butter from twenty-three or twenty-four pounds of milk, will the next day, perhaps, under appareutly similar circumstances of feed and temperature, require twenty-eight pounds. In addition to this daily variation in butter yield, which is undoubtedly determined, in large part, by the processes of nutrition, we find on an extended scale a constant variation for season. Let us illustrate this fact, so generally known, by a few statements: J. B. Broughton, of Malone, N. Y., has milked three hundred cows, and as stated in the fourth report of the Vermont Dairymen's Association, his butter yield in the spring, on hay, was in the proportion of one pound of butter to twenty-seven or eight pounds of milk. In June, on grass, the proportion was as one to twenty-one, and for the year as one to twenty-four. Another statement from the National Live Stock Journal for September, 1872, gives the spring proportion as one to twenty-six, the November proportion as one to seventeen and a quarter pounds. The record of the famous Jersey cow, "Lady Milton," states her butter yield as follows: We will tabulate a few other cases, covering a range of breeds, and give our author This table could be indefinitely extended, but in all my notes I have but one record where the autumn milk of any one cow made less butter proportionally than the early summer milk. One more quotation: Mr. Ellsworth, a very reliable and accomplished farmer of Barre, Mass., published in the Agriculture of Massachusetts for 1871-2, a record of the butter proportion of his herd of high grade Durhams. It is as follows, the trial being made once each week: From the tables we have now presented, covering the records of cattle under diverse circumstances of food and treatment, I think it may be assumed as a general truth, that the milk is, as the farmers express it, richer in the autumn than in the spring. Although this fact is usually attributed to the influence of the food, I think it is probably the effect of the time of calving, and I desire to claim an agency for the globules of the milk in securing these results. If, as we have shown to be the case, the globules, although decreasing in size, yet make a nearer approach to an uniformity of size, as time passes from the calving, it would seem, theoretically at least, that there would be a greater saving of the butter from the churning, from the cow old in milk, than from the same cow when a fresh milker. As illustrating the influence of uniformity of size of globule in producing butter, I give the following experiment, which, although made with reference to solving the problem of the effect of keeping distinct breeds for the supply of a dairy, and in so far as it refers to the breeds, anticipating some conclusions which are to be developed further on, yet may, in this place, be considered simply as results derived from milk of different physical characters. The experiment was made by taking twenty fluid ounces of Jersey milk, and dividing into two parts as nearly alike as could be. The same was done with the like quantity of Ayrshire milk: Jersey milk; average size of globules, 1-5252 inch. These milks were cooled to 60° and churned by shaking in a Florence flask. Ten ounces Jersey milk; butter came in five minutes; churned eighteen minutes; product, 136 grains of butter. Ten ounces Ayrshire milk; butter came in twenty minutes; churned thirty minutes; product, 76 grains of butter. These twenty ounces of milk, churned in two lots, prodaced 212 grains of butter. Ten ounces of Jersey milk plus ten ounces of Ayrshire milk, mixed and churned; butter came in thirteen minutes; churned twenty minutes; then removed butter by a filter and churned the buttermilk ten minutes longer; product, 179 grains of butter. Difference in favor of churning each milk separately, 33 grains, or about eighteen and a half per cent. Let us investigate the size of the globule in the buttermilk: It is acccordingly seen that there is an indicated waste in mixing milk of various sized globules, for the purpose of churning. This can be accounted for in this case in either one of two ways-breed causes, or dissimilarity in size of globule. It is probable that the first cause obscures the experiment somewhat, yet the latter influences in a large degree. I desire those who do not accept this explanation (of an accessory cause) to try the proportion of butter to milk in the autumn, in milk from cows newly calved, and those who have calved in the spring. To rightly understand the various problems connected with the dairy cow, it is absolutely essential that all the influences affecting her milk should be known, in order that variation, caused by circumstance or individ. ual peculiarity, may be successfully eliminated from those changes produced in the milk by the feed. BREED VARIATION. The variation consequent on breed has either been almost entirely overlooked by the chemist in his analytical investigation, or else it has been most unphilosophically assumed not to be of importance. Certain it is that unless the chemist deals with typical specimens, and gives accurately and minutely all the circumstances attending the nutrition and hereditary peculiarities of the animal from which the milk was obtained, together with an account of the treatment of the milk between the milking and the analysis, also with the circumstances attending the milking, we can have no correct series of analyses by which the composition peculiarities of one milk can be scientifically studied in its relations to other milk. Let me call attention to the fact that the nutrition of the animal affects the percentage composition of its milk, as does also the position of the milk with reference to the whole time occupied in milking. Furthermore, each teat probably yields a milk of somewhat dissimilar percentage composition; for a careful series of observations made by Mr. Edward Burnett, of Deerfoot Farm, Southboro, Massachusetts, show that the rear teats produce a milk richer in cream than the forward ones.* If, then we have gland variation, milking variation, season variation, food variation, individual variation, breed variation, it will be realized how important it is, for scientific study, that the complete history of the circumstances preceding an analysis should be given in every case. We have already given an account of some of the variations in the morphological constituent of the milk, which accompany certain conditions in the cow, and certain positions in the milk. We will now proceed to give the result of our observations illustrating the variations produced by breed. The Jersey, the Ayrshire, and the Dutcht breed are those with which I am not only most familiar, but the only breeds whose milk I have had any opportunity to investigate. In the Jersey and the Ayrshire milks my morphological studies have been fairly complete; in the Dutch milk, more limited. The Jersey cow has been bred wholly with reference to butter; the Ayrshire cow for cheese and butter; the Dutch cow principally for the production of cheese, although butter and beef are each claimed for her by her American advocates. The belief in the universality of inheritance as a law, and that the animal structure is but an equilibrium between many forces acting both in the present and from the past, would lead us to infer that any changes brought about by selection or otherwise, disturbing the relative action of any one force, would, in time, produce recognizable changes in an animal. It is, in fact, impossible for any one who has a positive belief in the inflexibility of causation, as a law, to expect that a continued seeking for a product in cheese or butter, could take place in any community of intelligent breeders without influencing, in time, the character of the animal. We therefore approach our inquiry with a well grounded expectation of finding differences in the milk which will correspond to the uses to which the milk is applied, among a civilized and highly intelligent people. Each breed has not only its own type, but also includes individuals who depart to a greater or less extent from the typical form. Under one aspect, the typical form may be considered as being the form possessed by the larger numbers of the best bred cows of a breed. In the discussion which is hereafter to follow, I have endeavored, in every case, to apply my observations and conclusions to the product of animals which may be *The experiment of Mr. Edward Burnett shows percentages as below: By Dutch I mean those large black and white cattle, imported from Holland, and frequently called "Holsteins" in the United States. considered as typical, for if we should take the exceptional cow for the purpose of study we should make confusion indeed. JERSEY MILK. The milk from the Jersey cow, when examined microscopically, is seen to possess globuies larger, both absolutely and on the average, than does the milk from the other two breeds. Another noticeable and very important observation is upon the absence of granules. These granules do, however, appear in the milk in limited numbers, and can always be detected in considerable number in the skim-milk and the buttermilk. In consequence of this structure, this milk, when set in percentage glasses, throws up its cream with rapidity, and presents usually a blue appearance in the skim-milk. I have known a specimen of Jersey milk to throw up the bulk of its cream in four hours, although it usually requires a longer time for this process to take place. On account of this peculiarity of globule, this milk is one unfitted by structure for the milk retailer. The cream rising to the surface during the interval between the milking and delivery, does not readily mix again with the milk. The quick rising of cream is, however, of importance to the butter dairyman, as it is, in the breed we are considering, united with a completeness, which is indicated by the blue skim-milk. The cream from the Jersey cow can, therefore, be skimmed from the pans at a somewhat earlier stage than can the other creams, without producing thereby waste. When the skim milk is set in a cool place, it is seen to throw up very little cream, although even kept for a long time, in this respect differing from the skimmilk of the typical Ayrshire. This will be better understood if we reflect that it is the milk globule which gives color to milk, and the absence of this globule would, therefore, be indicated by a change of color. If all the globules of the milk were of the size of the largest, the skim milk would probably be nearly the color of water; if the small globules are very numerous, and inequilibrium in the fluid, a skimming of the cream could take place without noticeably affecting the color of the remainder. In considering the Jersey milk in its butter relations, we must consider that the size of the globule would indicate an easy churning quality, and a strong "grain" to the butter. As a matter of repeated observation, this is not only the case, but the enveloping membrane appears weaker than that which incloses the fat in the Ayrshire or Dutch milk examined. This weakness is indicated not only by the globules being more readily ruptured under the field of the microscope, but also by the effect of the chemical action induced in the mi'k upon standing. In Jersey cream, kept for some time, ether will detect much more free fat than in Ayrshire cream of the same age. This comparative weakness of the globule is well shown by the following experiment, which explains itself. The cows were selected in the second instance with sole reference to the unformity of the size of the globule: |
