When infants are born prematurely, their power to digest food is much weaker than when they are born at full term. All the ingredients of their food should be lessened. Rotch advises the following formulas:

It is always well to begin with the administration of one dram of the milk mixture. The amount may gradually be increased, during the first two or three days, to the averages given in the foregoing table.

Mixed Feeding

Mixed feeding is often necessary. By it is meant the partial substitution of cow's milk or modified milk for the mother's milk. This is necessary when the mother's milk, though well digested, is deficient in quantity or in certain nutritive ingredients. If deficient in quantity but well digested by the infant, the mother's milk should be analyzed and a substitute made as nearly like it as possible. If the mother's milk is deficient in certain nutritive ingredients and the child is imperfectly nourished in consequence, the artificial food should so be prepared as to correct these deficiencies, at least in part. Two, three, or four feedings may be given daily. When a mother's milk is deficient in amount, it is best to lengthen the intervals between breast feedings by introducing a bottle of prepared milk between them. The best indication that the mother's milk is deficient in quantity or quality is the failure of the infant to gain steadily in weight.