Cows used for dairy products are genetically manipulated, artificially inseminated, and often drugged to force them to produce about four and a half times as much milk as they naturally would to feed their calves. These animals are often dosed with bovine growth hormone, which contributes to an inflammation of the udder known as “mastitis”—an extremely painful condition that up to 50 percent of cows used for their milk suffer from. Cows on dairy farms are also routinely mutilated without painkillers by having their horn tissue burned or gouged out of their heads, holes punched in their ears, and part of their tails cut off. Once their milk production declines, cows are sent to a terrifying death in a slaughterhouse to be ground up into hamburger.Like humans, cows produce milk only when they’re pregnant or nursing. In order to keep the milk constantly flowing, farmers artificially inseminate cows over and over, often on devices called “rape racks.” After their calves are taken from them, mother cows are hooked up, several times a day, to milking machines so that the milk meant for their calves can be sold to humans.