再找别的书。说1916年开始，60年代成为主流，比较可信。
https://en.m.wikipedia.org/wiki/Broiler
Modern breeding
Before the development of modern commercial meat breeds, broilers were mostly young male chickens culled from farm flocks. Pedigree breeding began around 1916.[3] Magazines for the poultry industry existed at this time.[3][4] A crossbred variety of chicken was produced from a male of a naturally double-breasted Cornish strain, and a female of a tall, large-boned strain of white Plymouth Rocks.[5] This first attempt at a meat crossbreed was introduced in the 1930s and became dominant in the 1960s.
