A problem which must be met by many mothers is that of obtaining for their infants an adequate substitute for breast milk. The weaning period is a very critical time in the life of every infant. Its ability to properly digest and assimilate the food supplied will largely determine its state of health, provided it is kept free from infection.
Milk formulas for the feeding of infants are often made up to conform to certain fat requirements. Some infants apparently have difficulty in properly assimilating a milk with a high fat content. This may be due to a low fat tolerance on the part of the infant or it may be caused by the physical curd character of the milk which has coagulated in the child's stomach. The curd obtained by the coagulation of the milk from some cows is soft and feathery, resembling breast milk in this regard. From the milk of other cows, however, a tough, rubbery curd is obtained which has an entirely different texture from that of breast milk.
The physical curd character of the milk can be approximated by the test which is described in this publication. The milk is coagulated by means of a solution of dry-scale pepsin and calcium chloride. The ease with which the curd formed can be wrung thru a fine-meshed cheesecloth is an index to its physical character.
Hill, R. L., "Circular No. 66 - Physical Curd Character of Milk and Its Probably Relation to Infant Nutrition" (1927). UAES Circulars. Paper 51.