CHAPTER XVII
MILK SANITATION
Cow's milk, like mother's milk, is made up of solids and water. In a previous chapter we learned that in one-hundred parts of mother's milk, eighty-seven parts were water and thirteen parts were solid. These thirteen parts of solids consist of sugar, proteins, and salts; this is likewise the case with cow's milk, except that in the case of the cow's milk, the sugar is decreased while the proteins are increased as will be noted by the accompanying comparative analysis:
| Fat | % 4.00 |
| Sugar | 7.00 |
| Proteins | 1.50 |
| Salts | 0.20 |
| Water | 87.30 |
| ——— | |
| % 100.00 |
| Fat | % 4.00 |
| Sugar | 4.50 |
| Proteins | 3.50 |
| Salts | 0.75 |
| Water | 87.25 |
| ——— | |
| % 100.00 |
Mother's milk is absolutely sterile, that is, free from the presence of germs; on the other hand, cow's milk is anything but sterile—the moment it leaves the udder it begins to accumulate numerous bacteria, all of which multiply very rapidly. Cow's milk is generally twenty-four to forty-eight hours old before it can possibly reach the baby. It is just as important to keep in mind these facts of milk contamination—dirt, filth, flies, and bacteria—as it is to plan for the modification of cow's milk for the purpose of making it more nearly resemble mother's milk. While mother's milk has about the same percentage of fat as cow's milk, it is almost twice as rich in sugar, and has only one-fourth to one-third as much protein. This protein is vastly different from that found in cow's milk, which you recall has a tough curd, as seen in cottage cheese. While mother's milk contains a small amount of casein similar to that found in the cheese of the cow's milk, the principal protein constituent is of another kind (lactalbumin), and is much more easy of digestion than the casein of cow's milk.
This is a most important point to remember, because the baby's stomach is not at first adapted to the digestion of the heavier and tougher protein curds of cow's milk. It requires time to accustom the infant stomach to perform this heavier work of digestion. There are a number of factors which must be borne in mind in the modification of milk, whether it be cow's milk, or goat's milk (for many European physicians use goat's milk entirely in the artificial feeding of infants): namely, the cleanliness of the milk, the acidity of milk, the difference in the curd, the percentage of sugar, and the presence of bacteria.
SUGAR
In the modification of cow's milk, sugar must be added to make up for the sugar which is decreased when the water was added to reduce the protein. There are several sorts of sugar used in the modification of milk. These sugars are not added to sweeten the milk alone, but to furnish a very important element needed for the growth of the baby. Sugar is the one element which the infant requires in the largest amount.
Milk sugar is probably most universally used in the modification of milk, but a good grade of milk sugar is somewhat expensive, costing from thirty to sixty cents a pound, and this places it beyond the reach of many mothers. It is added to the food mixtures in the proportion of one ounce to every twenty ounces of food. Cane sugar (table sugar) may also be used, but it must be clean and of good quality. It is used in rather less quantity than that of milk sugar, usually from one-half to one-third of an ounce by measure to each twenty ounces of food. Dextri-maltose (malt sugar) is very easy of digestion and may be used in the modification of milk. Maltose seems to help the children to gain more rapidly in weight than when only milk or cane sugar is used. It is also exceedingly useful in constipation, as its action is more laxative than any of the other sugars; but it should not be given to children who vomit habitually or have loose stools.