From swill milk to certified milk: progress in cow's milk quality in the 19th century

Industrialization and urbanization jeopardized infant nutrition during the 19th century. Cow's milk was produced in the cities or transported long distances under suspect conditions. Milk was contaminated with bacteria or adulterated with water, flour, chalk and other substances. When distilleries proliferated in the metropoles, their waste slop was fed to cows which then produced thin and contaminated swill milk.

Following a press campaign in the USA, the sale of swill milk was prohibited by law in 1861. Bacterial counts became available in 1881 and helped to improve the quality of milk. Debates on pasteurization remained controversial; legislation varied from country to country. Disposal of the wastewater of millions of inhabitants and the manure of thousands of cows was environmentally hazardous. It was not until 1860 and after several pandemics of Asiatic cholera that effective sewage systems were built in the metropoles. Milk depots were established in the USA by Koplik for sterilized and by Coit for certified milk. In France, Budin and Dufour created consultation services named goutte de lait, which distributed sterilized milk and educated mothers in infant care.

Multiple efforts to improve milk quality culminated in the International gouttes de lait Congresses for the Study and Prevention of Infantile Mortality.