"Failed" hatch?

[amandam1903]

I just incubated 17 eggs, took 4 quitters out at lockdown and the eggs were very dark so a few I wasn't too sure about when I locked down. Anyways, 5 pipped on day 20 and we're hatched out in about 4 hours.

I waited until day 22 and candled. 1 internally pipped, the others I wasn't sure. My kids wanted to eggtopsy so we did and there were 7 chicks out of 8 eggs left. The air cells all looked good, nobody shrink wrapped or super wet. Yolks on most absorbed.

I did feel like the air cells were a little small on day 14 so I dropped the humidity down a bit. Could that be what killed them? We are going to hatch some more soon and I want to make sure I am not missing anything.

I did just read that eggs from chickens in their 2nd year of laying are best and these were from chickens who have been laying for 8 months.

I used a Nurture Right 360.

 

[Debbie292d]

I do not open the incubator once they are in lockdown as chicks hatched can live 72 hours on the yolk they absorbed.

I also don't pay attention to the air cell size as it's different every time. I just keep the humidity around 40-50% until lockdown, and then up it to 70%.