Yet cow's milk as furnished by nature is not a proper food for young infants. This milk was intended by the Creator for the nourishment of calves, and they were accordingly supplied with four stomachs and the process known as "chewing the cud" in order that this milk might be diluted and finely divided before the calf is really called upon to digest it. Consequently, before supplying cow's milk to young infants, it should be carried through some process by which it can be artificially finely divided for infant digestion, and this process we know as "modification," which consists in diluting and adding certain substances in order to get the different elements in about the same proportion as exists in good woman's milk. In the larger cities of the North "milk laboratories" exist where the doctor can send a prescription for the baby's food, just as he would send to the "drug store" for s medicine, and have it filled with the same exactness. Of course we have no such laboratories in the South, and my intention is to show that for all practical purposes the same results can be obtained by "modification at home" by an intelligent and careful mother. The reason "modification" is necessary is that, while cow's milk contains all of the necessary elements, it does not contain all of them in the same proportions and forms as are found in good woman's milk. Thus chemical analysis shows that woman's milk contains 3 to 5 per cent. fat, I to 24 per cent. proteids, 6 to 7 per cent. sugar, 0.20 per cent. mineral salts, 87.3 per cent. water. Average herd cow's milk contains 4 per cent. fat, 31⁄2 per cent. proteids, 41⁄2 per cent. sugar, 0.75 per cent. mineral salts, 87.25 per cent. water. Thus we find the two milks about equal in fat, while cow's milk is much higher in proteids and mineral salts and lower in sugar than woman's milk. Also the reaction of cow's milk is acid, while that of woman's milk is alkaline. Thus in giving cow's milk to infants the percentage of proteids must be reduced, while the percentage of sugar must be raised, and the reaction changed. Again, the proteids of cow's milk are not exactly the same in kind as those found in woman's milk. The proteids of all milk consist principally of casein and lactalbumin; the lactalbumin being in solution and easy to digest, while the casein is insoluble and forms into hard curds when mixed with the gastric juice. Koenig says: "Woman's milk contains, lactalbumin, 1.26 per cent.; casein, 1.03 per cent. Cow's milk contains, lactalbumin, 0.53 per cent.; casein, 3.02 per cent." Thus cow's milk contains about one-half as much lactalbumin (the easily digested part) as woman's milk, and nearly three times as much casein (the part which is hard to digest). Thus during the first few days it is necessary to reduce the proteids of cow's milk below that found in woman's milk, as the proportion of casein is so large. As soon as the infant's stomach is used to the casein, the proteids can be gradually but steadily increased. Fat is much more easily digested, and that of the two milks is practically the same in kind. Consequently, the fat can be given in larger amount than the proteids. If we dilute the "whole milk" sufficiently to get the proteids at a proper percentage, the fat would be reduced very much below the amount which the infant needs and can easily digest. Thus, in order to reduce the proteids without reducing the fat too much, it becomes necessary to either add fat in the form of cream, or use a milk which contains an excess of fat. Chemical analysis has proven that milk and cream are not different things, cream being merely milk which contains an excess of fat. Thus 20 per cent. cream contains: Fat, 20 per cent.; proteids, 3.05 per cent. ; sugar, 3.90 per cent. Whole milk contains: Fat, 4 per cent. ; proteids, 3.50 per cent.; sugar, 4.50 per cent. Thus the difference in fat is 16 per cent., while the difference in proteids is only 0.45 per cent. Rotch says that fat free milk contains 4 per cent. proteids. Thus high cream and even skimmed milk contain very nearly the same percentage of proteids. The easiest way to get very rich milk is to use only the top layers after the cream has risen. A few years ago Dr. Holt caused a number of tests to be made at the Walker Gordon Laboratory which proved the following: That if mixed herd milk is bottled soon after cooling and kept on ice nearly all of the cream rises in four hours, and that the upper layers will contain practically the same percentages of fat after four hours as they would in eight hours or twelve hours. This saves a good deal of time and makes a great difference in the freshness of the milk. Thus Knowing this, it becomes very easy to get a milk-cream combination containing practically any per cent. of fat desired, by varying the number of ounces of "top milk" used. Thus Averge herd milk contains.. Let a quart of fresh herd milk stand on ice for four hours. Top 24 ounces averages. .4% fat. Top 20 ounces 66 66 66 66 These six strengths of milk are all that will be required in feeding most healthy infants from birth up to fifteen months, after which time modification is no longer needed. Practical experience has shown that most healthy infants have about the same needs as far as nourishment is concerned and that most of them can be fed in about the same way. As a general guide in "Home Modification" the following table has been taken from Holt's "Diseases on Infancy and Childhood" as giving the percentages as best adapted to the different ages during infancy : The usual method of modification uses only 10 per cent. milk or top 3, 7 per cent. milk or top 1⁄2, and 4 per cent. or whole milk to dilute and adds sugar of milk and lime water, to get formulas somewhat similar to the above. This method has two disadvantages: First, after the child is taking much food it requires the second quart daily, only the "top third" or "top half" of which is used, which in a year's time would make a considerable difference in the cost of milk, and in many families this is a point to be considered. Second, when by diluting the 10 per cent. milk (or top 3 milk), which contains three times as much fat as proteids, the percentage of fat in the resulting mixture is raised from I per cent., the starting point, to 3 per cent. or 32 per cent, which is about right at four months, in order to advance the proteid strength, the present method changes to a “7 per cent. milk” or “top 1⁄2 milk" in which the fat is only twice as abundant as the proteids. This necessitates a considerable temporary reduction in the fat strength in the food given. Thus in getting the proper proteid advance with this 7 per cent. milk, the fat percentage in the resulting mixture would be reduced from 32 per cent. down to 22 per cent., as the milk to be diluted is so much poorer in fat. As the infant at this time is already digesting 31⁄2 per cent. fat, it creates a decided loss to go back to 21⁄2 per cent fat. The objects of this paper are: 1. To show that the high point in the fat per cent. having been reached, it is entirely unnecessary, and for the time being detrimental to reduce it. 2. The fat percentage being properly worked out, it is entirely unnecessary to consider the proteid percentage. |