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Popular Science Monthly/Volume 73/August 1908/Facts Concerning Milk

FACTS CONCERNING MILK
By A. E. P. ROCKWELL, M.D.

WORCESTER, MASS.

THE cow is the foster mother of our civilization. And fortunate are we in being able to secure the services of this humble animal in our endeavors to arrest the most important cause of race suicide. For our greatest menace in this direction resides in the fact that an alarming proportion of infants must be vicariously nourished at some period of their development by the cow.

Owing, on the one hand, to that sinister development of our industrial system which compels many women to engage in competitive factory labor, and the invasion by women of almost every field of human activity; and, on the other hand, to the unwholesome influences surrounding those immersed in the fatuitous struggle for social supremacy, we find that each year rewards us with a larger percentage of women who are unable to nurse their children.

One way, then, of registering the progress of civilization is in noting the constantly increasing proportion of infants in the rearing of which artificial feeding plays an important part.

It may, with some truth, be urged that owing to the educational influence of mothers' clubs and the like, and the entreaties of physicians, there is among a certain class of women possibly a greater desire to nurse their little ones; but of what avail is this inclination if their previous condition of servitude to a life not in consonance with this result, renders them physically unable to perform this important function? And it must be noted that this physical unfitness is not necessarily due to a failure on the part of the glands to which the duty of supplying lacteal fluid is assigned.

Many mothers are able to furnish for their children a fluid, but it can scarcely be designated as milk, owing to the fact that the blighting effects of unhappy or unwholesome emotions so common among wage earners, the over-worked housewife and the social aspirant render the milk entirely unfit for food.

To-day we live under high-pressure conditions, with accompanying wide fluctuations in emotional experiences, developing resultant temperamental effects notably prejudicial to the manufacture of a wholesome milk in the nursing mother. The chemistry of the emotions plays an important part in the welfare of the child.

It has been shown that as the result of vexation, disappointment, grief and kindred emotions certain highly organized chemical products are elaborated within the economy which find their way into the blood stream and thus into the mother's milk, rendering it more or less harmful to the infant receiving it. Hence, if it were possible during the period of lactation to transmute all women representative of the classes above indicated into wholesome, phlegmatic German peasant mothers, our milk problem in its multiform aspects would be wonderfully simplified. The present social order not only makes impossible such conditions, but we must calmly face a future in which maternal inefficiency in this regard will be even accentuated.

Some of us believe the solution of the vexed question of the overpopulation of the earth is resident in this problem of artificial feeding, particularly as certain statistical relationships seem to be springing up between the notorious modern birth rate and inefficient maternal nourishment, and we are learning that unsatisfactory as is artificial feeding at its best and perilous as it may become, it is, in any event, much more likely to be productive of good results than the attempt to nourish an infant on the milk of the mother physically, occupationally and temperamentally unfit.

Again, our apprehension must not be transformed into despair, for unremitting educational endeavors will ultimately insure a better milk supply and greater intelligence in its use. So while milk is regarded the most perfect of all foods for the young or old, in sickness or in health, the milk problem is virtually the children's problem, for cows' milk, modified in accordance with the requirements of each particular case, has been found to be the only practical method by which nature's plans for early nourishment of the human infant may be successfully imitated. Any attempt" at the solution of this question, therefore, which fails to emphasize our guardianship of the interests of the child would be calamitous.

Surgeon-General Walter Wyman of the Public Health Service says:

The steady decrease in general mortality does not apply to infants. It is recognized that gastro-intestinal disease is the largest single factor determining infant mortality. This enormous loss of potential wealth is of grave concern to the state and worthy of most careful consideration.

Further he says:

Dr. Eager gives figures to prove that the high infant mortality may be attributed almost entirely to impure milk.

Inasmuch as one child in every twenty in our large centers of population dies before five years of age of maladies traceable directly or indirectly to contaminated cows' milk, it may be well to outline very briefly some of the properties of this indispensable food and a few of the problems associated with its production and supply.

Milk is at once the most important and the most perishable of all food products. Fresh milk is the most perfect mechanical emulsion known and contains roughly proteids (albuminoid substances equivalent in nature to the white of the egg) fat, in the form of minute globules which are later represented as cream, milk sugar, certain mineral salts and water. There is more or less fluctuation in the proportion in which these substances appear in all milks, particularly the milk of cows, owing chiefly to the development (in some instances covering periods of many hundred years) of certain breeds of cattle, possessing, among other qualities, certain characteristics as milk producers. I say chiefly to the development of breeds, because repeated experiments with various breeds have shown that it is not possible to alter materially the proportion in which the various constituents of milk appear in the milk of any given cow by any process of feeding yet discovered.

Improved methods of feeding increase the total quantity of the output, but not materially the quality, and any attempt to force by feeding an increase in the percentage of any one of the ingredients in the milk (particularly the fat content) may increase slightly for a short time such content, but it soon drops to the normal for each cow, and the experimenter has run the risk of ruining the animal experimented upon.

A popular fallacy prevails which enshrines in the minds of the uninformed the belief that milk having a large percentage of fat is rich milk, and hence, the best milk. Milk rich in fat and the best milk from both a physical and a chemical view are not synonymous terms, either as a matter of domestic economy or as applied to its use for infants. While all good milk must possess fat, the consideration of the amount thereof from a nutritive standpoint is second to that of the proteid content except in a certain few selected cases, which rarely include babies or young children.

Dr. J. A. Gilbert, writing in The Medical Record (New York), takes the view that this devotion to "rich" milk has no logical basis. In our earnest search after a fat milk, he says, we have probably gone too far. To quote from an editorial in The Hospital (London) which notes Dr. Gilbert's opinion appreciatively:

The milk which is richest in cream is not, therefore, the most nutritious, for the very simple reason that a rich milk is less easily digested and absorbed than a milk in which the fat percentage is low. As far as its other constituents are concerned, a milk poor in fat is as valuable a food as a milk rich in fat.

Owing, then, to ignorance or personal interest, recent discussion of the milk problem throughout the land has revolved around the percentage of fat in milk and undue prominence has been given this phase of the question.

Protein is the most important nutritive content in all milks, and is the one toward which breeding efforts and the attention of the consumer should be directed. As protein, the tissue former, is the most valuable constituent of milk, it follows that an endeavor to insure a high percentage of this indispensable food element should be the aim of any legislative enactments having in view the establishment of milk standards (of which we hear so much in this day) and not the maintenance nor increase of the fat content. And when it is understood, moreover, that as the fat content of milk increases, the tendency probably is toward the decrease of the proteid content, the folly of this course becomes patent.

Legislative measures referable to the production, transportation, sale and consumption of milk have had and will continue to have a most important, direct and indirect influence upon the character of the herds supplying the milk to the several communities in which such legislation is operative.

As laws represent the will of the majority and as the majority in this instance are the consumers, it behooves us, as such, to understand what is desirable in the matter of milk and then through educational effort work toward the attainment of it.

A word here regarding the leading characteristics of breeds of cattle may not be amiss. All cattle may be roughly divided into three general classes according to the purpose for which they are designed—the beef breeds, the general purpose breeds and the dairy breeds, with the last of which only we are concerned. The dairy breeds are again roughly divided into two great classes.

First, those who give large quantities of milk containing a normal proportion of fat divided into small globules. Of this type the Holsteins and Ayrshires are examples.

Second, those in whose milk a large percentage of fat is found in the form of large globules but who in general are somewhat delicate and comparatively small milkers.

Jerseys and Guernseys are typical of this class.

Before the introduction and general use of the separator, a device which separates the cream by centrifugal force from the fresh milk, the dairy breeds represented in the second class were in great demand, because with their milk the cream rose quickly to the surface on standing and was easily skimmed. The skimmed milk, however, of these breeds has the bluish color, familiar to all housewives, and is possessed of small nutritive value. Excessive fat production having been developed at the expense of the food value contained in the whole milk. Moreover, the fat globules are large, being about three times the size of those of the breeds representative of the first class, and hence much more difficult of digestion by children and most invalids.

In this connection, Chas. W. Townsend, M.D., of the Boston Floating Hospital, says:

The quality of the fat of Jersey and Guernsey milk, aside from its quantity, is in some infants a cause of digestive disturbance; I have many times seen babies gain but slowly and show fatty stools on Jersey milk modifications, even when the percentage of fat was low, while the same babies gained rapidly and digested well the modifications having the same amount of fat, made with the milk of Ayrshire, Holstein or common red cows.

Since centrifugalization was introduced much more attention has been given to breeds giving more rational milk, for the separator removes as easily and at the same cost the fat from a low as a high percentage milk. Hence, the effort as indicated has been to develop breeds which would produce skimmed milk which was nutritious and regarding the manifold virtues of which as a food we need not enter into here.

So highly developed are some of these breeds of the first class that it is worthy of note that many individuals are to be found that will give their weight of milk each month and total butter production for the year, equivalent to one half their weight.

Hence, we find in breeds representing the first class, namely, the Holsteins and the Ayrshires, the qualities particularly desirable in the family cow, inasmuch as their milk is best for infants, and furnishes a perfectly balanced ration alike for older children and adults.

Again, important as are the chemical analysis of milk and urgent as is the necessity of its being delivered fresh and uncontaminated, the question of the vigorous health and temperament of the individual cow is quite as vital.

Let us then again consider the relative merits of the two classes of dairy cows as heretofore indicated, in relation to their claim for excellence in this indispensable particular. Mention will be made only of the leading breed in each class in order to emphasize the illustration.

It is a well-known fact that the Jerseys, as bred and cared for in this country, have a highly irritable nervous temperament, and are more difficult to feed, rear and manage than any other breed.

The Holsteins, on the contrary, are a large, healthy breed of placid temperament, great constitutional vigor, enormous digestive and producing capacity, comparatively resistant to disease, and flourish to a high degree in our trying climate. The same qualities which commend the wet nurse in the performance of the function which the child's natural mother is unable to perform, are those which should commend to the community the cow which now, more than ever, sustains to the infant population the relationship above indicated.

Common knowledge independent of scientific observation sustains the fact that a nurse with poor or delicate digestion, sensitively and highly organized, irritable nervous temperament, doubtful vital resource or resistance, is entirely unsuitable to rear a child. The same is true of the cow, and her individual adaptability must now be subjected to the same scrutiny. Many an infant has had its life imperiled or has been lost owing to its receiving its nourishment from a nurse who has suffered from disappointment, anger, hysteria, indigestion, lack of exercise or the like.

Much of our artificially fed infant mortality is due, directly or indirectly, to the presence in cows' milk of similar poisons generated in nature's wonderful laboratory and as defiant of test-tube analysis as are those other qualities in the milk of strong, hardy cows which, for want of better names, we designate as vital energy or vital force.

Speaking of vitalizing power in the milk of certain cows as compared with others, Professor Carlisle, of the Wisconsin Experiment Station, says:

The point I wish to make here is that there is such a thing as vitality in milk, and that it is of equal if not greater importance than is chemical composition especially for the milk supply of cities. And there can be no question but that the vitality of the milk is closely associated with the vitality of the animal producing it.

The effect, then, of laws requiring a high percentage of fat will be to put a ban upon the most sturdy, healthy, normal, productive and useful breed of cows the world has ever known, for they are to be found in every country of the globe and probably produce more milk and by-products than all other breeds combined. It will encourage the sale of the milk product of a breed which is neither hardy nor vigorous; which is probably more susceptible to tuberculosis and other diseases, owing partly to the fact that their delicate constitution requires housing more months of the year than any other breed; a breed giving a milk not only entirely unsuited to the purposes of artificial feeding of infants, but possessing excessive fat and other deleterious properties to such a degree that many of the cows of this breed are unable to rear their own calves; a breed originating in a salubrious climate, reared with the tenderest care, and brought to this inclement land to be exposed to conditions unnatural to them or their ancestors and therefore resulting in a milk product which, according to modern standards, is undesirable in many ways.

Many state institutions throughout our commonwealths maintain herds of Holsteins, some of which are among the finest in the land, in the confident belief that it would be impossible to supply such an abundant quantity of highly nourishing milk through the medium of any other breed.

Thomas Morgan Rotch, M.D., the distinguished authority on the diseases of children, speaks as follows regarding the value of the milk of this particular breed:

For instance, good Holstein milk is at times not salable on account of its total solids not coming within the limits of the law (Massachusetts State Standard). The law demands during winter 3.70 per cent, fat and 13 per cent, solids, while in the summer 3 per cent, fat and 12 per cent, solids. As we all know, the Holstein milk, unless the cows are especially fed, falls below this standard. Now, from a medical point of view the Holstein milk is exactly what we find best for infant feeding and it is an extremely good milk for any one to drink. The immense number of infants, however, who live entirely upon milk should be taken into consideration in this question, and I believe that the people should be allowed to buy this milk just as they should be allowed to buy a milk modified to suit a special infant who is being taken care of.

Too much can not be said or done to encourage the production and consumption of a food product which possesses nutritive elements of the right kind in the proper proportion, and nourishing qualities of such high value—a product which is essential to the proper development of the child, upon the future health of.which the state becomes dependent for its prosperity a product which has made healthy, contented and prosperous the nation, which for two thousand years has enjoyed its benefits.

As we have seen, no cow can obey the mandate of a legislature, no matter what liberty she may be allowed to exercise in the choice of her food. Some protection against adulteration and other forms of fraud in these selfish and greedy commercial days is necessary, but a standard based upon the total fat and total solids not fat, in milk, particularly when that fat percentage is placed so high that none of our most useful and healthful breeds can produce her,d milk in compliance with it, simply defeats the object for which it was designed.

For example, the milk test at the St. Louis Exposition was probably the most scientifically conducted and most illuminating in results ever made in this or any other country.

Among others the following groups competed in the tests: twenty-five Jerseys, five Brown Swiss, fifteen Holsteins and twenty-five Short Horns, not one of which produced milk up to the legal standard established by some states, and yet these cattle had been selected and fitted for an international exhibition, and were fed, groomed and tutored by experts in the art of milk production. Some of the very animals, valued perhaps at several thousand dollars, are producing milk in several different commonwealths to-day, which if sampled by the state inspector could put its owner in jail for violation of the law. Moreover, when we understand that the relative percentage of fat and solids not fat, in milk, varies in each cow with the period of lactation, time of day when the sample is taken, with the weather and seasons, the physical condition, and many other contingencies, and when we realize that two quarts from the same cow can differ; also two quarts from the same milk pail and mixing tank, some of the difficulties in establishing a just, arbitrary standard may be appreciated.

It is difficult to induce the public to realize that refined methods of analysis, the more careful attention to breeds and breeding, the great difficulty of supplying from considerable distances, the ever-increasing urban demand, the introduction of centrifugalization and other important considerations have entirely changed the complexion of the milk problem within a very recent period.

Many of us do not realize that much of the milk consumed in our large cities is taken from herds kept as far as 300 miles or more from the consumer, and when it is delivered to him is frequently forty-eight hours old. The problems surrounding the transportation of such milk in the summer season may be in part appreciated when we know that the presence of 5,000 bacteria to the cubic centimeter is considered a reasonably low count and that under favorable conditions this number is capable of doubling by geometrical progression every half hour.

Samples of commercial milk taken in New York city recently showed 35,200,000 bacteria to the cubic centimeter; London, 31,888,000; Washington, 22,134,000. That seventy-eight typhoid germs in one cubic centimeter of milk increased in seven days to 440,000,000 furnishes an illustration of the possibilities in this direction, and when one realizes that one cubic centimeter is equivalent to about sixteen drops, some idea may be gained of the bacterial population of much of the milk we drink.

Milk removed properly from a perfectly healthy cow, and kept in receptacles previously sterilized, contains practically no bacteria, and may at a low temperature be-preserved for days without material change. When, however, these precautions are not observed the results are as above indicated. Not all these germs are harmful, but many varieties are exceptionally prejudicial to the health of children. Each of 500 epidemics recently investigated, including typhoid fever, scarlet fever and diphtheria were found to be caused by contaminated milk. That 11 per cent, of milk samples examined from Washington contained tuberculosis germs need not be considered as exceptional and can be verified by the examination of data of a similar nature from other cities. And when we understand that the milk supply of New York city, for example, is derived from the product of 35,000 farms and shipped from 700 creameries located in six different states, it is easy to appreciate some of the difficulties surrounding the protection of the community from the sources of infection contained in milk.

In recent years the prominence given to tubercular disease in cattle, with the consequent appearance of the tuberculosis germ in the milk of such cattle, has entirely overshadowed the importance of certain other diseases in cows, likewise accompanied by the presence in the milk of cows so suffering of enormous numbers of bacteria characteristic of such diseases. I refer particularly to the disease known as "Mastitis," an inflammation of the udder accompanied by the presence of certain bacteria largely of the pus-forming type which are discharged with the milk in enormous numbers.

While possibly a smaller number of cows suffer from this disease than from tuberculosis (and herein probably lies the reason why this important source of infantile mortality has been overlooked), many cows not only suffer from repeated acute attacks in which far greater numbers of these bacteria are eliminated with the milk than tubercular germs in pulmonary tuberculosis or even tuberculosis of the udder, but not a few suffer from a more or less intractable, chronic type of this malady which renders them a never-failing fountain of mischief.

Probably the major portion of the grave intestinal disturbances of children are due directly or indirectly to the presence in milk of the bacteria characteristic of this disease and the ptomains, toxins and kindred substances which always accompany certain types of bacteria activity. And notably is this true of milk, for it is a most excellent example of what is known technically as a culture medium, meaning a substance favoring in a high degree bacteria development and growth. Some one says: "Yes, while this is all very bad we can protect ourselves by pasteurizing or sterilizing our milk." While either of these processes properly carried out will destroy the germs or for a few hours prevent their activity they can not destroy the ptomains or like highly organized poisons already present, and as dangerous to human life as they are crafty in eluding chemical analysis.

Pasteurization, then, the proper execution of which requires much skill and training, removes from contaminated milk but part of the danger while its palatability has been impaired and its nutritive properties somewhat altered, and we are obliged to drink the carcass of millions of bacteria still suspended in it. The tendency, moreover, of pasteurization is to put a premium upon dirt, which gains entrance to milk chiefly through careless methods in milking and caring for milk after it leaves the cow which carries with it a great multitude of bacteria and is the most important source of bacteria contamination of milk.

It has been computed that the people of the City of Berlin drink in one year many hundred pounds of cow-barn filth suspended in milk.

Milk so produced as to be free from dirt (unhappily not the milk of commerce) may be considered also comparatively free from bacterial growth.

Pure milk, fresh milk produced free from germ and dirt contamination in the stable and during handling and transportation, is the birthright of our children, is what we all desire and is the goal toward winch the various boards of health, cattle inspection bureaus and similar agencies of our commonwealths are striving for against heavy odds.

Two great obstacles stand in the path:

1. The difficulty, even under repeated inspection of premises on which milk is produced (inspection in some instances emanating from four or five separate sources) to induce the producer to adopt cleanly methods of production.

2. The increased cost to the consumer of milk so produced, a cost which the poor man can not and the well-to-do are disinclined to meet. For in many of our states it is doubtful if such milk as we would all like to use could be delivered at our doors, under the conditions of increased cost which prevails to-day, at 15 cents a quart and allow the farmer and the retailer each a reasonable profit thereon; for in farming, as in other lines of business, cost of production must include interest on investment, taxes, depreciation, labor, raw material (hay, grain and the like) insurance, and similar charges.

But what remedy may we hope to apply to extricate ourselves from the present dilemma? Rather than fritter away the money and energies of the various states in trying to maintain standards for fat and solids not fat which are not only impossible of attainment, but a constant menace to the farmer and a prolific source of irritation and discontent to all concerned in the milk industry. Let us now concentrate our efforts upon an endeavor to insure a pure milk supply for the children. This can best be done by taking the machinery of the state boards of health and kindred agencies now employed in cattle and milk inspections and direct their activities along the lines of a certified milk supply which has been applied with measurable success in connection with certain cities—the plan being to enlarge the scope of the work, as at present conducted, so as to include all the dairies supplying the commonwealth with milk whether situated within or without the state.

Certified milk means that a dairy has been properly inspected by trained and competent officials who give to the owner thereof a certificate allowing him to place upon the containers of milk leaving his farm (for a certain period until a subsequent inspection is made) a label indicating that the milk is absolutely clean and produced under sanitary conditions by a healthy herd.

This plan minimizes the technicalities and red tape ordinarily attending work of this nature and promises to vouchsafe to us and our children a milk supply in character consonant with the demands of the civilization in which we live, but it can not be secured unless a majority of us demand it and are willing to pay for the additional, expense which it entails.