Specification Chickens are the most common type of poultry in the world, and were some of the first domesticated animals. They are a major world wide source of eggs and meat called chicken. It is prepared as food in a wide variety of ways, varying by region and culture. The prevalence of chickens is due to their being almost completely edible, and the ease of raising them. Modern varieties of chicken such as the Cornish Cross, are bred specifically for meat production, with an emphasis placed on the ratio of feed to meat produced by the animal. The most common breeds of chicken consumed in the US are Cornish and White Rock. Chickens raised specifically for food are called broilers. In the United States, broilers are typically butchered at a young age. Modern Cornish Cross hybrids, for example, are butchered as early as 8 weeks for fryers and 12 weeks for roasting birds. Capons (castrated cocks) produce more and fattier meat. For this reason, they are considered a delicacy and were particularly popular in the Middle Ages.