Early hatch's???

[retlaw]

Is over heating the only issue that would speed up hatching?

My first batch of eggs hatched early on their 27 th day.
!8 eggs total, 5 duds, 11 hatched and healthy with only the last one needing help.
1 egg was half develop, 1 egg fully developed that didn't make it out.
Only one crooked toe on the 11.

So I turned the incubator down a half degree.
Digital thermometers had different readings as always(some higher and some lower then 97.5C with the mercury one being at around 99F.

This batch came earlier.
Started pecking holes at the end of the 25 day, Early on the 26th day they started coming out.
8 on the 26th day all healthy. On the 27 day another One ringed the shell but the membrane was to dried out and couldn't break it so I helped it. The membrane was not going to break with out my help. It was like leather already.
And another I just had to break it out. Had just a tiny shell crack with out the membrane broken yet. The peeps were faint in the shell and I knew it was late compared to the others.
It seems to be just fine.

There is an egg that tried to come out with a small section of the shell gone but the membrane didn't break. So I know this one is dead.

20 eggs, 10 health hatched, 6 duds, 1 dead while trying to hatch, 3 still in shell unbroken.
No crooked toes.

So with out the dud eggs not being counted the hatching percentage seems to me to be fine.
I don't want to mess around with the temperature if I;am having success.

Is this early hatching just from the temps being a little high?
Wouldn't there be other issues with health if the temps were to high?

 

[ColbyNTX]

Yes, too hot will cause this. Also, eggs being stored too hot before incubation could start the process. You should really try to get your temp right. 50% hatch rate is not very good. If I ever see less than 80% I would be really upset.

 

[retlaw]

Its 50% I believe because one hen is not producing fertile eggs.
So 33% of the eggs are written off right off the bat. (3 hens)
They are the ones I call duds.

If so then I am at 14 to 10 which is 71.4%.

I have marked the dates on the eggs and every second day there was a dud.

I hope she starts giving me fertile eggs soon.
She produced last year so I hope she and the tom didn't get into some sort of misunderstanding. LOL

The biggest issue in correcting the temperature is know what thermometer is correct.
Four in the incubator and no two read the same.

I guess I will turn it down another 1/2 degree again.
The storage room is below room temperature so that should not be the issue.

Would tough membranes also be a side effect of over heating the incubator?
Noticed a few this time.