Why do the eggs grow to day 18 and then not hatch?

[Little Farm Girl]

Several years ago, before we knew anything about adding certain amounts of water, and keeping the humidity right(I mean we didn't even have a humidity gauge) and all of that, we were setting 42 eggs, and we would have at least 34 babies hatch. Now, we set them and worry about adding more water, and everything we've been more recently told to do, and Almost all of the eggs grow until day 18, and we're like, we are going to have a good hatch, and then only a couple hatch.

So my question is, Why in the world do so many grow good, and then not hatch? I would really like to do something about it, so if you have any suggestions, or just overall the steps you take to have a good hatch, that would be awesome. Thanks so so much!!

These pictures were taken on day 25. Thanks again.

 

[Little Farm Girl]

Also, we have an aweful little giant incubator that we are going to give away so that we stop using it, but these eggs were incubated in our amazing Hova Bator. These were only a few of the eggs from that batch that grew then died.

 

[Shadrach]

Several years ago, before we knew anything about adding certain amounts of water, and keeping the humidity right(I mean we didn't even have a humidity gauge) and all of that, we were setting 42 eggs, and we would have at least 34 babies hatch. Now, we set them and worry about adding more water, and everything we've been more recently told to do, and Almost all of the eggs grow until day 18, and we're like, we are going to have a good hatch, and then only a couple hatch.

So my question is, Why in the world do so many grow good, and then not hatch? I would really like to do something about it, so if you have any suggestions, or just overall the steps you take to have a good hatch, that would be awesome. Thanks so so much!!View attachment 1752595View attachment 1752590 View attachment 1752591View attachment 1752592 View attachment 1752594View attachment 1752595
These pictures were taken on day 25. Thanks again.

One possible reason is the eggs were disturbed during the first three days of the set.

 

[Little Farm Girl]

One possible reason is the eggs were disturbed during the first three days of the set.

Interesting! So don't touch the eggs until day 8 to candle them at all?

 

[Little Farm Girl]

One possible reason is the eggs were disturbed during the first three days of the set.

May I ask why, or what it affects?

 

[313759]

It definitely looks like they died, but I'm sure you already knew that. Sometimes things like this happen, reasons being beyond us. Perhaps they were weak? Or they didn't develop properly? I know that one time we had cracked open an egg that didn't hatch and the chick didn't have a head, poor thing. But that may be a more rare case. Sorry that I didn't exactly answer your question, but hopefully the few things I've gotten from experience help out a bit or give an idea. Perhaps crack open the eggs? Maybe you can see what went wrong if anything did. But like I said, sometimes they just die for reasons beyond us.

 

[BullChick]

Some of the air cells look small.

 

[Little Farm Girl]

It definitely looks like they died, but I'm sure you already knew that. Sometimes things like this happen, reasons being beyond us. Perhaps they were weak? Or they didn't develop properly? I know that one time we had cracked open an egg that didn't hatch and the chick didn't have a head, poor thing. But that may be a more rare case. Sorry that I didn't exactly answer your question, but hopefully the few things I've gotten from experience help out a bit or give an idea. Perhaps crack open the eggs? Maybe you can see what went wrong if anything did. But like I said, sometimes they just die for reasons beyond us.

Yes, we always crack open the eggs, and see what beautiful babies died, but they always seem perfectly healthy, so I suppose they might just be weak..thank you! And I'm sorry about your baby, that's aweful.

 

[Little Farm Girl]

Some of the air cells look small.
View attachment 1752607

According to our pictures, and your picture, it looks like the humidity is to high, correct, and wrong, all at once.

 

[Shadrach]

May I ask why, or what it affects?

I can't find the research paper link atm. If my memory serves me the paper was in the Worlds Poultry Science Journal.
In short from memory, the way the eggs are set in the first three days and the rate and orientation of the turns made by the hens influences the hatch rate success. I believe it has something to do with making sure the embryo is positioned in the egg so it doesn't make contact with the shell.
The last three days are also critical.
If I remember once my other computer is fixed I will try and find the paper.
The study also showed that the hatch rate success when a hen hatched a clutch undisturbed was considerably higher than when an incubator was used.
You can find some of this information in a book I recommend edited by Dr Joseph Barber; The chicken, a natural history.
Now I will doubtless get told by some of the keener hatch-along and candling enthusiasts that handling the eggs is absolutely fine. This isn't what serious research shows.
So no, don't keep handling the eggs be they in an incubator or under a hen. With a decent incubator get the settings right and leave it alone. With a hen; just leave her to get on with the job.
I realise that for some the fascination of watching an egg grow is irresistible and exciting but in general it's not good practice.