Incubating eggs from older hens.

[Beemz]

Hi everyone! I’m new here.
I have 20 years of keeping hens and incubated many times.
I’m currently using an Rcom which is holding its temp and humidity perfectly, cross checking with additional instruments.
My issue is for the past 3 hatches I have a LOT of DIS chicks- either pipped externally, internally or not at all. The humidity runs at 40% until end of day 18 then upped to 65% for hatch.
My query is, all my hens are old stock, like 3 years up to 5 years.
Fertility isn’t a problem- that’s nearly 100% but getting out of the eggs IS.
Is there such a thing as thicker membranes on those eggs being laid by older hens?
Thanks for reading

 

[nchls school]

I have hatched many eggs from 3-5 year old hens; even a ten year old hen and all those eggs hatched. Yes, age could be a factor along with genetics, diet, and more.

Recently I've had a similar problem; chicks DIS, pipping but unable to hatch, etc. I replaced my rooster and the few eggs I have under a hen are developing. You might find that your problem is not the hens but a genetically weak rooster.

 

[Beemz]

I have hatched many eggs from 3-5 year old hens; even a ten year old hen and all those eggs hatched. Yes, age could be a factor along with genetics, diet, and more.

Recently I've had a similar problem; chicks DIS, pipping but unable to hatch, etc. I replaced my rooster and the few eggs I have under a hen are developing. You might find that your problem is not the hens but a genetically weak rooster.

Thank you so much for your reply-
So the father is a Silkie cross- looks Silkie to a non expert eye but no black skin, no blue ear tuft?
The hens are industry standard, brown, ex barn hens.
Cock is about 2 years old and hens 4.5 years.
Does this throw any light on anything.
The chicks that I have helped out if I get to them in time are perfectly healthy and have grown into strong healthy birds. I was too late earlier and had another 2 DIS but I got 2 out that had pipped 48 hours ago and made quite a big hole but didn’t get any further.

Is there something weird about Silkie crosses?

 

[Beemz]

I have hatched many eggs from 3-5 year old hens; even a ten year old hen and all those eggs hatched. Yes, age could be a factor along with genetics, diet, and more.

Recently I've had a similar problem; chicks DIS, pipping but unable to hatch, etc. I replaced my rooster and the few eggs I have under a hen are developing. You might find that your problem is not the hens but a genetically weak rooster.

Just to add, the chickens free range on around 2 acres, access to grass, woodland etc. Fed on a high quality layers pellet and a bit of grain at bedtime.

 

[nchls school]

I've had numerous silkie crosses and found nothing weird in the way of reproduction. As to chicks being healthy and strong, ditto with mine. However, with mine, most died before hatching-some soon after incubation started-some halfway through-other at hatch time-still more when pipping. With a previous rooster I was getting many chicks and few DIS. That changed with the new rooster being in residence. Now, with the third rooster there was one infertile and the rest were developing; no DIS--yet. One of my hens is four.

I guess I'd bet on your rooster being the problem. It's not likely all your hens have the same problem; everything considered. If it is your rooster then the difficulty could show in all the hens' eggs.