Cows produce milk for the same reason that humans do—to nourish their young—but calves on dairy farms are taken away from their mothers when they are just 1 day old so that their mothers’ milk can be sold to humans.
Female cows are artificially inseminated shortly after their first birthdays. After giving birth, they lactate for 10 months and are then inseminated again, continuing the cycle. Some spend their entire lives standing on concrete floors; others are confined to massive, crowded lots, where they are forced to live amid their own feces.
Cows have a natural lifespan of about 20 years and can produce milk for eight or nine years. However, the stress caused by the conditions on factory farms leads to disease, lameness, and reproductive problems that render cows worthless to the dairy industry by the time that they’re 4 or 5 years old, at which time they are sent to be slaughtered.
