Comparison of the Composition of Cow’s and Human Milk
The following analyses give the comparison between cow’s milk and human milk:
| Human Milk. | Cow’s Milk. | |
| Nitrogenous substances | 2.35% | 4.30% |
| Fat | 3.40% | 3.80% |
| Sugar | 4.85% | 3.70% |
| Salts | .20% | .60% |
| Water | 89.20% | 87.60%49 |
Buying, Care, and Sterilization of Cow’s Milk
Cow’s milk varies considerably in nutritive properties, and for the growing infant who receives no other food it is extremely important that it be of the first quality. It should be tested in every possible way to enable one to form a correct estimate of its value, and unless unquestionably good should be rejected.50 When fresh from the cow, not more than two hours old, and of superior quality, it need not be sterilized, but should be put into perfectly cleansed and sterile vessels,51 and kept in an ice-box, or refrigerator, at a temperature of 50° to 60° Fahr.52
When obliged to buy the ordinary milk of commerce, select if possible that which is put up in glass jars. There are farmers who do this. Each jar is sealed, marked with the owner’s name and address, and the date of sending. Such milk does not become contaminated with bad air in transit, cannot be tampered with by middlemen, and must be free from dirt, as it would show through the glass; each customer gets exactly a quart, with all the cream that belongs to it; moreover, the owner, having attached his name, has thus put his reputation at stake, and is not likely to sell inferior milk. When this is not practicable, search for the best and cleanest dairy, and see that the milk is delivered as soon as possible after being received at the dairy. Milk should not be bought from small stores.
The best milk comes from cows that have good pasturage, with clean running water, and that are fed in winter on dry fodder and grain, and not on ensilage and brewery waste.
According to the reports of the American Public Health Association, one fifth of all the deaths among infants may be traced to the milk supply, and there is no doubt that most of the sickness of bottle-fed children, during the summer months, is directly due to the unhealthy condition of their food.
It then becomes the imperative duty of every mother, nurse, or other person who has the care of children, to learn, if she does not already know, the simpler tests for milk, and something of the philosophy of the feeding of her charge.53 When such knowledge is more general, and women are able to determine intelligently the quality of the milk which is offered them, then will milk-dealers be forced to cease mixing, adulterating, and otherwise tampering with the milk, which, as a general thing, is sold at the farms in excellent condition.
The first object is to secure a good quality of milk; then comes the consideration of how it shall be prepared: this must be in such manner as shall render it as nearly like human milk, in composition and digestibility, as possible.
Comparison of the tables just given shows that cow’s milk contains more nitrogenous matter and salts, and less sugar, than human milk.54 By diluting with water to reduce the protein and salts, and adding sugar and a little cream, the proportions of these different substances may be made to approximate those in mother’s milk. In both the sugar is the same—lactose, or milk-sugar; the fats are also much alike in each; but the albuminous matter of cow’s milk differs somewhat from that of human milk, particularly in the way in which it coagulates in the presence of acids. Human milk forms into small, light, feathery curds; cow’s milk into large, compact, not so easily digested masses. It is necessary, therefore, to seek the means for preventing the coagulation of milk in large curds in the stomach of the child—in other words, to so treat cow’s milk that it shall coagulate more like human milk. This may be done in two ways:
(1) By mixing into the milk some substance which shall separate the particles of albumen from each other, and so cause it to form into smaller masses.
(2) By partial predigestion.
To accomplish the first, it is necessary to use some diluting substance of a harmless nature; if it be nutritious, so much the better. For this, Mellin’s food, barley-water, veal broth, lime-water, and gelatin are recommended.
Mellin’s food is a partially predigested grain, in such a condition that it can be assimilated by the infant; barley-water is valuable for its potash salts, in which cow’s milk is deficient, and which the growing babe needs; veal broth is rich in lime; and lime-water neutralizes the acid of the gastric juice, so that milk is not acted upon so strongly, and consequently forms into a lighter curd.
The second method is that of partial predigestion, and is accomplished by the use of peptonizing agents, among which Fairchild’s peptogenic milk-powder is good (directions for its use will be given later). On account of the expense of these preparations it is not probable that they will come into general use, except in cases of sickness.
It is therefore evident that dependence must be placed almost entirely upon attenuants to render the casein of cow’s milk more easily digestible. Probably for this Mellin’s food is as good, if not better, than any other of the recommended preparations. It is not injurious, is nutritious in itself, and is a good diluting agent, causing milk to form into looser curds than it would otherwise do, and it contains sufficient sugar to require no further addition of this substance.
Now arises the question whether milk shall be sterilized for infants’ feeding. The weight of evidence seems to be as follows: if it is possible to see the conditions under which the cows live, and to know that they are unquestionably good, that the animals are in perfect health, that the milk is drawn from cleansed udders into cleansed vessels by clean hands, kept in a cool place, and used fresh, then it is probably wise not to sterilize it. All milk otherwise obtained should be made sterile before using, and as soon as possible after milking. Looking to the standard—human milk—there are no organisms in it. That alone is sufficient reason why cow’s milk should be freed from them.55
Again, most bottle-fed children do well during the cold weather of autumn and winter; in summer the mortality is very great among them, especially in the poorer districts of large cities. It is well known that the chances for life with children nourished by mother’s milk are greater than with those artificially fed. Why should this be? There is no doubt that it is owing to the presence in cow’s milk of extraneous substances, the products of bacterial growth—products which are often absolute poisons; and it is highly probable that cholera infantum, in a vast majority of cases, may be traced to the action of such poisons.
Under favorable conditions of temperature, such as prevail in the warm months of summer and early autumn, micro-organisms grow with almost incomprehensible rapidity in any substance which is suitable food for them. Milk is such a substance; and, as bacteria multiply with wonderful rapidity, millions forming in a few hours in every thimbleful,56 it is perfectly evident that they must produce something. This something may or may not be of a harmful nature, depending upon what species of organism produces it. I have no evidence at hand to show what is the nature of the product of any one organism which finds a home in milk; but there are instances on record where the nature of the product of certain bacteria is known: for example, the diphtheria bacillus. This little rod, growing upon the outside of the tonsils in the human throat, produces a most virulent poison, which, taken up by the circulation, pervades the whole body, and often so enfeebles its functions as to destroy it.57
Reasoning from analogy, it is not impossible to suppose that other organisms may produce substances of a similar character, poisonous in their effects, and which, when taken into the alimentary canal, may produce very grave digestive disorders.58
Further, bacteria, by their multiplication, use some of the constituents of milk for their food, thus changing its composition. It is very important to prevent this growth, or, in case it has begun, to check it before it has rendered the milk unwholesome food. Hence the necessity of sterilizing immediately all milk which is not received directly from the cow. Besides, cows are often infected with tuberculosis, foot-and-mouth disease, splenic fever, pneumonia, and other dangerous disorders. Their milk may be a direct cause of infection. When it is sterilized there is less danger from it; but even then it is not, of course, a wholesome food, because of the poisons which may be produced in the animal during the progress of the disease, and because a sick and weakened cow cannot give wholesome milk.59
In many cities, through the influence of children’s hospitals and sanitariums, the knowledge and methods of sterilizing milk for infants’ food are gradually spreading.
Circular wire frames, made something like casters, and fitted with eight bottles, each holding enough milk for one feeding, may be bought for the purpose of sterilizing at almost any pharmacy. The frame is to be set in a kettle with water in the bottom, which on boiling produces steam, the heat of which does the sterilizing.60 This is an easy method. Another good way is to sterilize at a lower temperature for a longer time, as less change is produced in the constituents of the milk by the lower degree of heat. This may be easily done by immersing the bottles in water at 190° Fahr., and maintaining that temperature for an hour.61
Care of Feeding-bottles. Great care must be taken in cleansing feeding-bottles. When they can be washed immediately after using, it is easy to make them perfectly clean; but when this is impracticable they should be put to soak in cold water, then washed with hot soap-suds, and last boiled for ten minutes in clear water. If flecks dry on the inside, put a teaspoon of rice, or coarse salt, into the bottle with a little water, and shake well until all is removed. Never use shot: it might cause lead poisoning.
Plain rubber nipples alone should be used, never the tube attachment. The nipples should be washed clean and dried after each nursing. Before again using the nipple it should be put into boiling water for ten minutes, and only the rim of it should be touched in handling. The nipple should never be put into the mouth of another person to test the milk.
Condensed Milk. When a large percentage of the water of milk is evaporated, and sugar added, a thick syrup is formed, known as condensed milk.
It is made extensively in Switzerland and America. When sealed air-tight in cans it will keep indefinitely.
Its average composition—a mean of 41 analyses by Prof. Leeds—is as follows:
| Water | 30.34% |
| Fat | 12.10% |
| Milk-sugar | 16.62% |
| Cane-sugar | 22.26% |
| Albuminoids | 16.07% |
| Ash | 2.61% |
| ——— | |
| Total, | 100.00 |
Owing to the additional sugar it is impossible to dilute it so that the protein and sugar shall approach the standard of human milk.
Children fed with it are plump, but have soft flesh; they are large, but not strong, and lack the power of endurance and resistance to disease. Their teeth come late, and they are very likely to have rickets.62 This is enough to indicate that it is not a proper food upon which to feed a child exclusively.
Condensed milk is valuable in emergencies or in traveling, and may also be used occasionally when for any reason the milk supply fails. It has the advantage of being free from ferments and easily kept.
There are physicians who recommend the use of condensed milk, and no doubt, compared with the germ-laden, watery fluid called milk, obtainable in the poorer sections of large cities, it is infinitely better. It should always be diluted with at least ten times its bulk of water.
Preserved Milk. Preserved milk is milk which has been condensed and canned without the addition of sugar. It would be a valuable food for children were it not that it is expensive, and will keep but a few hours after the can is opened. By sterilizing it in flasks with narrow necks, plugged with cotton, it may be kept as other milk is for an indefinite time. As soon as the can is opened, the contents should be poured into a glass or earthen vessel, for, on exposure of the milk to the air, chemical action takes place with the tin.63
Farinaceous Foods. There are many farinaceous forms of food prepared for the use of infants and children. Probably the most valuable of them are those made according to the Liebig process. The starch of the grain from which such foods are prepared is, in the process of manufacture, changed into soluble dextrine, or sugar (glucose), by the action of the diastase of malt: the very thing which an infant cannot do.
When we consider that the digestion of starch in the alimentary canal consists of this change into glucose, and that it is effected principally by the saliva and the pancreatic juice, the significance of the value of such foods will be seen.
It is also well to bear in mind that neither of these functions (the secretion of saliva and pancreatic juice) is developed in an infant until it enters the third month of its life, and then but very imperfectly. That alone shows the necessity of excluding all starch from its food up to that age.
Mellin’s food and malted milk are prepared according to the Liebig process. In them the starch has been converted into soluble matter by the action of the ferment of malt. It is really a partial predigestion. Mellin’s food does not contain milk.
The following analysis of Mellin’s food is one made by Professor Fresenius, of Wiesbaden, Germany:
| Non-nitrogenous substances soluble in water | 69.38% |
| Non-nitrogenous substances insoluble in water | 3.18% |
| ——— | |
| Total carbohydrates | 72.56% |
| Nitrogenous substances soluble in water | 4.69% |
| Nitrogenous substances insoluble in water | 5.06% |
| ——— | |
| Total albuminoids | 9.75% |
| Total salts, mostly phosphoric acid, carbonic acid, and potassa | 4.37% |
| ——— | |
| Total moisture | 13.32% |
| Cane sugar, none. Reaction, alkaline. |
Comparative analysis of Mellin’s food, prepared for use, with that of woman’s milk and cow’s milk.
| Constituents. | Mellin’s Food. | Woman’s Milk. | Cow’s Milk. |
| Fat | 2.36% | 4.00% | 3.30% |
| Albuminoids | 2.83% | 2.50% | 3.50% |
| Carbohydrates | 6.81% | 6.50% | 5.00% |
| Salts and inorganic matter | .74% | .50% | .70% |
| Water | 87.26% | 86.50% | 87.50% |
| Cellulose | A trace. | — | — |
| Cane-sugar | None. | — | — |
| Starch | None. | — | — |
| Dr. A. Stutzer, Bonn, Germany. | |||
This analysis shows that Mellin’s food bears comparison with milk. It is easily digested, and as an attenuant for milk may be used without harm during the early months of life, but it should not be used to the exclusion of milk for more than a few days at a time, and then only when milk is not retained by the stomach.
Later it is doubtless a valuable addition to the regular daily food of the child.
Malted milk is made from selected grain and desiccated or dried milk. To prepare it for the infant it needs only the addition of water. It is probably one of the best substitutes for milk, but should not be used for any length of time when it is possible to get good milk.
The starch of grains may be converted into dextrine and glucose by the action of heat as well as by the action of diastase, so that when flour is subjected to a certain temperature, and for a certain time, this change is produced.
Nestlé’s food, Imperial Granum, Ridge’s food, and some others are made very carefully from selected wheat by this process. Nestlé’s food contains dried milk.
These foods are all valuable when made into gruel or porridge, but should be used very sparingly under the age of twelve months, and then only as attenuants for milk, not as substitutes for it.
Dr. Mary Putnam Jacobi, editor of “Domestic Hygiene of the Child,” by Uffelmann (a translation), in speaking of the value of the various preparations of infants’ food on the market, says: “There is not the slightest reason to prefer them to milk or its preparations, except that the latter requires more care; and for any intelligent and affectionate mother this reason is quite insufficient.... During the first year the baby is building up tissues and organs that are to last him throughout life; and these will work well or ill according to the degree of perfection and precision of structure which they attain at the beginning. And this depends to an immense extent upon the suitability of the food, not only to be digested, but to be absorbed, and then to be assimilated and organized.
“So mysterious are the properties of the molecules of albumen and fat, when once they have been thrown into the whirl of the living organism, that we must strive to deviate as little as possible from the exact forms given to us in nature, if only because we do not know what remote effects might result from the deviations. If nature provides the albumen of milk and a living fluid, we cannot expect the same results from any other albumen, or from long dead organic matter, as condensed milk.”
The farinaceous foods have value, but they cannot replace good milk, which should be almost the sole food of the child to at least the age of ten months, and the principal nutrient to the age of two years.
When a baby is nursed, and its mother has an abundance of milk, it takes nothing else during the first ten or twelve months of life. When a baby is artificially fed, this fact should be borne in mind. The important thing is to attain as nearly as possible to the standard that nature has set.
Biedert’s cream mixture and the whey mixture are valuable for young infants and those which for any reason do not thrive on milk.
Amount for Each Meal. A child is nourished, not by what it swallows, but by what it digests. Giving too much or too concentrated milk is very unwise, for the delicate system cannot manage it, and too frequently the meal becomes a source of pain rather than of strength. Each individual babe will require a little different treatment in this respect from every other.
In general, for the first six weeks from two to four tablespoons at a feeding may be given; from that age to six months, from four to eight tablespoons, gradually increasing the amount to twelve tablespoons at one year.
Dilution. Cow’s milk is more easily digested when diluted with water, and we are more likely to dilute too little than too much. The amount of water used should vary with the age and strength of digestion of the child. As a rule the new-born infant should have two parts water to one of milk; at four months equal parts of milk and water; at ten months one part water and two parts milk. When digestion is particularly feeble, it may be necessary to dilute milk with six or eight times its bulk of water.
Manner of Giving. It is best to give milk from a bottle so constructed that suction is necessary, for it induces the flow of the digestive juices. Use the plain rubber nipple; those with tube attachments which extend into the bottle are to be avoided, on account of the difficulty of making them perfectly clean inside. Cultures from these tubes always give large numbers of bacteria, as do also those made from the nipples, unless they are boiled.