An average dairy cow produces between 6 and 7 gallons of milk each day, or approximately 2,500 gallons of milk per year. Dairy farms in the United States produce between 21 and 23 billion gallons of milk each year.
As of 2013, there are over 50,000 dairy farms in the United States. Most of these farms are family owned and operated. The size of a dairy cow herd is typically between 100 and 135 mature cows. California and Wisconsin are the top two states for dairy production, with California being responsible for over 20 percent of all milk production in the United States.