Is it better to obtain the 10-per-cent milk by using a mixture of milk and cream, or as top-milk?
If one can get milk fresh from the cows, the top-milk is to be preferred on account of freshness. The food can then be made up when the milk is but a few hours old. In cities, if one uses bottled milk, the upper third may also be used. But if one buys milk and cream separately, it is usually more convenient to mix these, as the cream will not rise upon milk a second time with any uniformity.
How can one obtain formulas in which the fat is twice the proteids?
By using for dilution a 7-per-cent milk (i.e., milk containing 7 per cent fat) which serves as the primary formula from which all the other formulas of this series are derived.
In 7-per-cent milk the fat is just twice the proteids.
How can one get the 7-per-cent milk?
(1) As top-milk, as described on page 64; or, (2) by mixing three parts of milk and one part of ordinary (16 per cent) cream; (3) from any of the milk laboratories it may be obtained directly. As in the case of 10-per-cent milk, the top-milk is generally to be preferred to a mixture of milk and cream.
How should the food be prepared during the early months?
It is convenient in calculation to make up twenty ounces of food at a time. The first step is to obtain the 10-per-cent milk or the 7-per-cent milk to be used as the primary formula. Then to take the number of ounces of this that are called for in the formula desired.
Note.—One should not make the mistake of taking from the top of the bottle only the number of ounces needed in the formula as this may give quite a different result.