Operational for more than 60 years, American Dairy Corp., operates Dairy Queen, one of the largest fast food systems in the world. The restaurant serves a variety of food items and treats, including cheeseburgers, chicken sandwiches, hot dogs, chicken wraps, French fries, onion rings and side salads. Based in Madisonville, Ky., Dairy Queen also offers soft serves as well as pies and birthday cakes, along with beverages, such as smoothies, shakes and coffee. American Dairy Corp. is a part of Berkshire Hathaway Inc.