Milk produced under such conditions is usually described as “certified milk” and is often prescribed as infant food without being pasteurized or sterilized. But if there is any doubt about the source of the milk and the method of its handling, it should be strained into a clean receptacle through filter paper or a thick layer of absorbent cotton and subsequently boiled or pasteurized.
When the nurse is in a position to offer advice about the baby’s milk she must explain the importance of always obtaining the freshest, cleanest and purest milk possible, no matter what it costs.
Whether certified or not the milk must always be placed in the refrigerator or some other place at a temperature of 50° F. as soon as it is received and it must be kept cool and clean. Mother’s milk, which is being imitated, is clean and sweet and free from disease germs.
Keeping the milk cool means keeping it at a temperature of 50° F. Keeping it clean implies cleanliness of the milk itself, the utensils, the nurse’s hands and the destruction, by sterilization or pasteurization, of disease germs. Those which are likely to be present in infected milk are streptococci, tubercle bacilli, colon bacilli, germs of typhoid, diphtheria and scarlet fever.
The amounts and proportions of the constituents of the substitute feeding will be specified by the doctor, as well as the intervals between feedings and the amount to be given each time. But the doctor’s careful adjustment of the milk formula to the baby’s immediate needs and digestive powers will be set at naught unless the nurse is absolutely accurate in preparing and giving the milk.
The nurse’s invariable responsibility, therefore, is to keep the milk cool and clean and prepare and give it accurately.
The nurse will appreciate the necessity and principles of modifying cows’ milk for the human infant if she will consider for a moment, the differences between mother’s milk and cows’ milk, as indicated by the following table, and the reasons for these differences:
| Mother’s Milk. | Cows’ Milk. | |||||
|---|---|---|---|---|---|---|
| Fats | 3.5 | to | 4. % | 3.5 | to | 4. % |
| Sugar | 6.5 | to | 7.5% | 4.5 | to | 4.75% |
| Proteins | 1. | to | 1.5% | 3.5 | to | 4. % |
| Salts | .2% | .7 | to | .75% | ||
| Water | 87 | to | 88. % | 87. % | ||
It will be remembered that the tissues and bony skeleton are built by the proteins and salts (lime and phosphorus). Accordingly Nature supplies these in greater abundance to the calf, who grows so fast as to double his birth weight in about 47 days, than to the baby who scarcely doubles his within 180 days. The calf begins life with a physical need for the abundance of proteins and salts which are present in cows’ milk, and with digestive organs that can cope with them, but the baby needs less, can digest less and therefore must be given less. There are, of course, other and finer differences between the two milks and an attempt is sometimes made to meet these. For example, mother’s milk is slightly alkaline and cows’ milk slightly acid and the curd of cows’ milk is larger, tougher and harder to digest than that formed by mother’s milk. Accordingly some doctors add lime water to cows’ milk to make it alkaline, and render the curd softer, finer and more digestible by boiling it.
It is often not possible to give a bottle-fed baby the full 4% of fat which mother’s milk contains, and some doctors make the protein of the artificial mixture very much larger in amount than is found in human milk. The nurse will see that this is a matter which can be decided only by the physician.