Poultry farming is the process of raising domesticated birds such as chickens, ducks, turkeys and geese for the purpose of farming meat or eggs for food. Poultry - mostly chickens - are farmed in great numbers. Farmers raise more than 50 billion chickens annually as a source of food, both for their meat and for their eggs. Chickens raised for eggs are usually called layers while chickens raised for meat are often called broilers.In the United States, the national organization overseeing poultry production is the Food and Drug Administration (FDA). In the UK, the national organisation is the Department for Environment, Food and Rural Affairs (Defra).