"The Bovine Growth Hormones designed to fatten cows quickly also cause painful udder infections. Monsanto, the multinational chemical corporation, makes a widely used Bovine Growth Hormone called Posilac, which comes with the warning that it may cause a number of side effects, including swelling and infected udders. These infections transmit pus, or dead bacteria, and white blood cells into milk, causing a disagreeable taste and unpleasant color. Factory dairies sometimes mix the milk from infected udders with normal milk, so the infected milk with its offensive flavor and color is diluted. U.S. regulations allow milk to contain more pus cell concentrations that any other country in the world--almost twice the international standard of allowable pus." --p.85, "Harvest for Hope" by Jane Goodall.

I didn't know there was such a thing as "allowable pus."