How do you make air cells bigger in eggs?

[JustAChickenLoverOverHere]

I've gotten pretty confused on how to make air cells larger in chicken eggs. Do you raise humidity or lower it? The air cells have barely changed since day 7 and we're going on day 14 right now. The humidity was at about 24% when I wasn't watching it, and they didn't lose much weight.

 

[Ryguy3684]

I've always lowered the humidity when I need the air sacs to grow. If it hasn't grown enough from my day 7 and 14 candling, I drop it from day 14 until lockdown. The lower humidity you noticed wouldn't have caused the lack of weight loss. It should have had the opposite effect.

 

[JustAChickenLoverOverHere]

I've always lowered the humidity when I need the air sacs to grow. If it hasn't grown enough from my day 7 and 14 candling, I drop it from day 14 until lockdown.

Really? I don't mean to question you, but how is that logical/ethical?

 

[Ryguy3684]

No worries. Dry air in the incubator causes more water to evaporate from the egg, therefore increasing the air sac. That's how I've always understood it, but somebody can chime in if I'm mistaken.

 

[JaeG]

Are you sure your hygrometer is reading right? 24% is quite low for humidity and they should have lost weight at that level.

This article has instructions for calibrating it (and your thermometer):
https://www.backyardchickens.com/ar...incubator-thermometers-and-hygrometers.73634/

It's the average humidity over the course of incubation that matters so even if it swings from one extreme to the other it's not going to affect the eggs (unless it stays at the wrong humidity and prevents them losing sufficient moisture).

If the air cells still look too small at lockdown you can leave them at a low humidity until you start to get chicks externally pipping (provided you can keep an eye on when that needs to be).

 

[JustAChickenLoverOverHere]

Are you sure your hygrometer is reading right? 24% is quite low for humidity and they should have lost weight at that level.

This article has instructions for calibrating it (and your thermometer):
https://www.backyardchickens.com/ar...incubator-thermometers-and-hygrometers.73634/

It's the average humidity over the course of incubation that matters so even if it swings from one extreme to the other it's not going to affect the eggs (unless it stays at the wrong humidity and prevents them losing sufficient moisture).

If the air cells still look too small at lockdown you can leave them at a low humidity until you start to get chicks externally pipping (provided you can keep an eye on when that needs to be).

Yes I'm sure it's reading right. It was only for a day, so maybe that's why they didn't lose much weight?