Thirty-three years ago, two idealistic young people barely out of college joined forces to start a cheesemaking business. They scrounged up $2,000, borrowed twice that much and launched Vermont Butter & Cheese (now Vermont Creamery). Last week, Allison Hooper and Bob Reese—still partners and still friends—announced that they were turning the keys over to new owners:  Land O’Lakes, a vast international agricultural co-op with $13 billion in annual sales.