Temperature and humidity.

Chickens hatch out on days 20-21, ducklings and turkey-poults on days 26-27, goslings on days 29-31. In the middle period of incubation the temperature and humidity are maintained at a lesser level than in the initial period but the ventilation is increased.

During hatching out the temperature has to be brought down more, and the humidity and ventilation have to be increased. For hen eggs the initial period lasts from the 1st to 11th day, for duck and turkey eggs – from the 1st to 13rd day, goose eggs – from the 1st to 16st day. The middle period for all the eggs is defined as the period up to the beginning of hatching out and the hatch out period – from the moment when the cheep of nestlings can be heard in eggs.