... chicken is 21 days, it’s 38.2°C from 1st~6th day, 37.8°C from 7th~14th day, and 37.2~37 ... .5°C from 16th~21st day; incubation period of duck is 28 days, it’s 38°C from 1st~7th day, 37.8°C from 8th ... ~15th day, 37.5°C on 16th day, and 37.2°C from 17th ~28th ... .8°C from 1st ~8th day, 37.8°C from 9th ~18th day, 37.8°C on 19th day, and 37.0°C~37.3°C from 20th ...