Originally Posted by WalnutHill
Agreed but look at the air cells, they are ~5 day development at 30 + days.
Misting may be good for ducks, I don't know, but it's not good for chickens if humidity is so high that it can't evaporate.
Yes, misting is good for them!
Air cell development is a bit different form the moisture problem. Humidity is important but depending on when the chicks quit, air cell and moisture around the chick will be off--there is a lot of moisture absorbed into the chick and the air cell gets a lot bigger from lockdown to hatch.
To fine tune this hatch:
1. Work on temperature control
2. Lower humidity about 10% but watch air cell development(air cell development is more dependent on humidity than the moisture inside the egg--there is a membrane between them).
3. Add misting from day 8 to 18 along with a cool down cycle
4. make sure the eggs are turning 45% 4 or so times a day.
The thing to remember is that hatching eggs do not dry out so much as chicks absorbing the water.