Embryonic growth was the fastest and growing same mass consumed tha lest energy during from the 12th to the 15th day.

• 胚胎发育在第12孵化日龄到第15孵化日龄期间生长最快，生产单位重量的耗能最少，此期间虽是早成鸟胚胎低耗氧率时期，但又是快速生长的时期。