MY DRY HATCH INCUBATION UPDATE

[4th generation farmer]

Ok I have posted several times during this incubation process...I decided to dry hatch 18 eggs from my layer flock...humidity stayed between 22% and 26% the entire time..twmp stayed between 99.5 and 100 degrees entire time.

lock down was spose to start today but hubby started it yesterday temp stayed 99.5 and 100 and humidity was up to 80% since and 3 days till hatch and I've got 3 chick's fully hatched today and 4 more pipping...is this normal with dry hatch to hatch early...or is it due to dry hatching then doing 80% humidity a day early and starting lock down a day early

 

[NatJ]

is this normal with dry hatch to hatch early...or is it due to dry hatching then doing 80% humidity a day early and starting lock down a day early

Early or late hatch is more likely to be based on temperature than humidity. I've read that even 1/4 degree different temperature, if it goes on for the whole incubation period, can be enough to make a difference in hatch time.

Here's a thread from someone else who did a dry hatch, and their chicks hatched a bit later than expected:

https://www.backyardchickens.com/threads/does-dry-hatch-delay-hatch-time.1563442/

 

[4th generation farmer]

Update....I now have 9 chicks hatched of 18....7 have been hatched since yesterday and super early this morning and 2 just pushed their shells off themselves...all hatched out good and easily nothing stuck to them and not sticky or weak

 

[ChickyMudder]

Ive been told that lower humidity and higher heat hatches early because you dry out the egg and make the air-cell bigger.
But, if I had to guess id say putting them in lock down early triggered them to hatch early. Because you did a dry hatch it was successful because their air cell was bigger. Did they all absorb the yolk? With an early hatch, this would be my concern.
These are just guesses based on the best available data.

 

[sdm111]

I've been told that a higher humidity can come quicker.

Ive been told that lower humidity and higher heat hatches early because you dry out the egg and make the air-cell bigger.
But, if I had to guess id say putting them in lock down early triggered them to hatch early. Because you did a dry hatch it was successful because their air cell was bigger. Did they all absorb the yolk? With an early hatch, this would be my concern.
These are just guesses based on the best available data.

This isn't true. Temperature dictates how fast an embryo develops

 

[gimmie birdies]

I have dry hatched many times, ( not listening to digital humidity readings they are low) my humidity with a humidity reader -dial- is 50%. Only thing I would do different is maybe not dry hatch if the eggs are older and have big air cells.

 

[KEarthman]

Ok I have posted several times during this incubation process...I decided to dry hatch 18 eggs from my layer flock...humidity stayed between 22% and 26% the entire time..twmp stayed between 99.5 and 100 degrees entire time.

lock down was spose to start today but hubby started it yesterday temp stayed 99.5 and 100 and humidity was up to 80% since and 3 days till hatch and I've got 3 chick's fully hatched today and 4 more pipping...is this normal with dry hatch to hatch early...or is it due to dry hatching then doing 80% humidity a day early and starting lock down a day early

I've been told that a higher humidity can come quicker.

 

[NatJ]

Ive been told that lower humidity and higher heat hatches early because you dry out the egg and make the air-cell bigger.

I've read that higher temperature causes the embryo to develop faster, so it hatches earlier, no matter what the humidity is.

Lower humidity causes a bigger air cell, because the egg dries out more, but I have not heard of that affecting whether it hatches early or late.

if I had to guess id say putting them in lock down early triggered them to hatch early.

Why would that make them hatch early?

I thought "lockdown" just meant to quit turning eggs, and leave the incubator closed. There's nothing about that to cause early hatching. Turning definitely does not stop an egg from hatching (evidence: stories of chicks that hatch early while the turner is still running, and of course chicks under a broody hen.)

 

[ChickyMudder]

"Is said" by who? I've read quite a bit about incubation and hatching, and I haven't seen that. I'd be curious to learn more. (I've had times in the past when I "knew" something but was wrong, so if I'm wrong here I do want to figure that out.)

I know that low humidity definitely can cause the membrane to dry out and get hard after the chick pips the shell. So high humidity keeps the membrane "soft" (the way it was before) rather than letting it get dry. But I haven't heard of it getting softer than the way it started.

The shell gets thinner or weaker during incubation because the chick absorbs some calcium from the shell, but humidity does not seem to make eggshells softer. Even soaking in water does not make them soft.


Yes, that definitely happens. It's pretty well documented in various places.


I see why it would make sense, but I don't think it actually works that way. Even if the shell did get softer, that would not help the yolk sack absorb any faster, or affect any of the other details that make a chick mature enough to hatch.

Ill find the article about shells softening with higher humidity.
Is the trigger for yolk sack absorption a combo of age, and air from pipping?

 

[NatJ]

Ill find the article about shells softening with higher humidity.

Thanks!

Is the trigger for yolk sack absorption a combo of age, and air from pipping?

I don't know exactly what triggers them to absorb the yolk, but it definitely starts before pipping.

Examples of two sources that talk about when the yolk begins to be absorbed:

http://extension.msstate.edu/content/stages-chick-embryo-development
"Nineteenth day - yolk sac begins to enter body cavity"

https://sora.unm.edu/sites/default/files/journals/auk/v061n02/p0235-p0241.pdf
"About two days before the embryo is ready to be hatched, a rapid growth and unfolding of the tissues at the umbilicus causethat portion of the yolk which has as yet not been absorbed to be enclosed within the abdominal cavity."