In 1921 a few hundred dairy farmers founded Land O’Lakes in St. Paul after figuring out a way to create a longer-lasting butter. Today the farmer-owned cooperative comprises some 3,600 independent owners making 600 dairy products per year from 13 billion pounds of milk. Its offerings--including butter, cheeses, and even Purina animal feed--are sold in more than 60 countries. The farm below, in Lancaster, Pa., is home to 1,000 cows, which are milked three times a day. Their udders are automatically washed, disinfected, and dried, providing for healthier cows and higher-quality milk. When they’re done, a push of a button (by a human) allows the cows to exit the milking parlor and get back to grazing. In 2013, Land O’Lakes (No. 199 on the Fortune 500) churned out $14.7 billion in revenues.