Context: Since their domestication, a large number of breeds of chickens have been established, but with the exception of the white Leghorn, most commercial birds are of hybrid origin. In about 1800, chickens began to be kept on a larger scale, and modern high-output poultry farms were present in the United Kingdom from around 1920 and became established in the United States soon after the Second World War. By the mid-20th century, the poultry meat-producing industry was of greater importance than the egg-laying industry. Poultry breeding has produced breeds and strains to fulfil different needs; light-framed, egg-laying birds that can produce 300 eggs a year; fast-growing, fleshy birds destined for consumption at a young age, and utility birds which produce both an acceptable number of eggs and a well-fleshed carcase. Male birds are unwanted in the egg-laying industry and can often be identified as soon as they are hatch for subsequent culling. In meat breeds, these birds are sometimes castrated (often chemically) to prevent aggression. The resulting bird, called a capon, has more tender and flavorful meat, as well.

Question: Are there any purebreed lines for poultry today?
Answer: with the exception of the white Leghorn, most commercial birds are of hybrid origin.

Question: When did the poultry business boom in the United States ?
Answer: By the mid-20th century, the poultry meat-producing industry was of greater importance than the egg-laying industry

Question: How has breeding helped in the pultry industry?
Answer: light-framed, egg-laying birds that can produce 300 eggs a year; fast-growing, fleshy birds destined for consumption

Question: How can you normally identify a cock when recently hatched?
Answer: can often be identified as soon as they are hatch for subsequent culling

Question: What began in 1820?
Answer: Unanswerable

Question: What became present in the United Kingdom in 1900?
Answer: Unanswerable

Question: What was of greater importance than the poultry meat-producing industry in the mid-20th century?
Answer: Unanswerable

Question: How many eggs can male birds produce in a year?
Answer: Unanswerable

Question: What year did modern high-output poultry farms become established in the United States?
Answer: Unanswerable

Question: Why does no breeding for poultry exist today?
Answer: Unanswerable

Question: When did the poultry business end permanently in the United States?
Answer: Unanswerable

Question: How has breeding destroyed the poultry industry?
Answer: Unanswerable

Question: How can you normally identify a cock when it doesn't hatch?
Answer: Unanswerable

Question: What birds are castrated to increase aggression?
Answer: Unanswerable