The Babcock tester was first marketed in 1890. This device enabled farmers to test butterfat content of their milk and to improve their herd management. They could now select, for breeding, cows that produced quality milk.
Prior to its invention it was impossible to determine butterfat content in milk. Farmers were paid for their milk by volume. Unscrupulous farmers skimmed off the cream and added water to the milk to increase the volume, thus getting paid more. Skimmed and watered-down milk is not useable for processing cheese, ice cream or other products dependent upon high butterfat content.
Stephen Babcock, a biochemist at the University of Wisconsin invented this simple test, making improvements and standardization in dairy production possible.