273. Accuracy Desirable

Accuracy in modifying milk requires that the composition of the milk and cream be known. On a commercial scale or in a pediatric hospital where large numbers of children are fed, this is possible, but in the home it is not, although where a Babcock tester is available a determination of the fat and solids may be quickly made. If the milk is from Holstein or other thin milk cows, it will in general be safe to use 8 ounces with l£ ounces of cream and ½ ounce milk sugar, the whole to be made up to 16 ounces. With Jersey or Guernsey milk the formula given above for that class of milk may be used. When the family is provided with high-priced certified milk, the composition is generally known and the formula may be varied accordingly. It is sometimes recommended to take a certain quantity of "top milk" and dilute it to a given volume; but this method is not to be commended, because top milk is a very uncertain composition. It will vary to a marked degree with the temperature at which the milk is kept; while the cream is rising, the higher the temperature the richer the cream.

It will also vary with the original quality of the milk, cream from thin milk containing less fat than cream from rich milk, other conditions being the same. If top milk is to be used, it should be from milk of a fairly uniform quality and kept at practically the same temperature from day to day.

274. Precautions

A general supply of mixed milk should not be used if it can be avoided. Unless milk known to be sanitary and of fairly uniform composition can be procured, the milk of a single cow, known to be healthy, should be used. This cow should not be too far advanced in the period of lactation, should be rationally fed, and neither the cow nor her milk and utensils should come in contact with a person having an infectious disease or recovering from such. The milk should be drawn under cleanly conditions, cooled at once, and kept cold in a sanitary refrigerator until used. Such precautions are often difficult and sometimes impossible in large cities, except for the wealthy, a fact which greatly enhances the dangers from feeding children on cow's milk, especially during the summer months.

The use of all the knowledge and skill we now possess does not yet make it possible to perfectly simulate mother's milk by the use of other materials. We cannot yet attain nature's art in providing food for the human young.

275. Goat's Milk As Infant Food

Within a few years much attention has been given to goat's milk as a food for infants. The points urged in its favor are that one or more goats may be kept by a family having only a small area of land, thus insuring fresh milk, that the milk is economically produced, that this species is practically free from tuberculosis, though riot entirely immune, and, what is most important, satisfactory results seem to attend the use of the milk. It is objected that because of the long hair of the goat the milk is more likely to be contaminated, and the offensive odor from the animal's skin is liable to cause an undesirable flavor in the milk. Both these objections may be obviated by thoroughly cleaning the hair and skin of the animal and by drawing the milk in some yard or room outside the living quarters of the animals.

The composition of goat's milk appears to vary widely, as is shown by the following figures. Average analyses presented by several authors show a variation of the per cent of solid matter from 7 to 18. Analyses of the milk of several goats have recently been made at the New York Agricultural Experiment Station with results as shown in Table LI

It appears that the quality of the milk bears quite a marked relation to the amount of the yield, the smaller the yield the larger the per cent of solids. This is true of other mammals.

Goat's milk is seen to be greatly unlike human milk in its composition. It contains in many instances not far from the same percentage of solid matter, but the proportion of protein in the solids is much higher and of sugar much lower. The percentage of fat varies greatly.