Chicks dying Day 18/19 - genetics?

[AbL]

If you feel like doing it, you could try to do an egg necropsy and see if the chicks have obvious malformations or malpositions.

Thought about it, but I think I am not yet up to it
The second one is definitely dead, no movement the last 24h+
while the first one has pipped externally since this morning.

 

[AbL]

I had the same problem with my last batch of Japanese eggs I tried to hatch last month. But I was haveing some incubator problems. I had one chick looking really good, moving around and everything get all the way to piped than quite. The early quitters sound like the creeper gene the others sound like weak chicks not genetic. In my experience Japanese hatch way better under a hen rather than in and incubator. It could be the season, I’ve had less hatchable eggs this time of year, idk, I don’t know much of the science behind egg development and hatching besides heat, humidity and bam babies.

I had good results under hen and in incubator this year, but the rooster changed and the hens are younger then those in spring.
Maybe a combination of less mature birds and season.
Luckily one hatched on his own this morning. Three others still moving in egg, day 18/19

 

[AbL]

I observed that the air cell was huge in those who died in egg.
The three remaining have rather small air-cells. Maybe I was inattentiv with humidity rates or the hygrometer is off.
@Perris : Thank you for the "late embryonic death" key word, found a lot of infos!

 

[Perris]

glad I could help. Good luck with the current hatch!

 

[Yardmom]

I understand you are working with a rare breed, but be aware that one successful hatch doesn't mean your humidity is correct. Different times of year mean different relative humidity. What works in one season may not work in another. Staggered hatches are likely to make humidity more challenging as well... Let your birds mature a bit as well.

 

[AbL]

I understand you are working with a rare breed, but be aware that one successful hatch doesn't mean your humidity is correct. Different times of year mean different relative humidity. What works in one season may not work in another. Staggered hatches are likely to make humidity more challenging as well... Let your birds mature a bit as well.

I hatched different batches over the year in different conditions, never had a problem like this. Here are 2 succeding batches with the same outcome; but from the same couple. The third currently in lockdown has two eggs from a different couple, we'll see if they have the same problem. If so an incubation problem ismore prorbable,if they hatch all, the problem might be with the birds. I continue to observe.

 

[AbL]

To close this thread... four chicks in total hatched from three different batches. From the last three eggs, two hatched, one ceased to move again around day 19. One was mal positioned and pipped way of the side instead in the aircell, but he made it.

Seeing their color I'm not sure on of the other hens smuggled an egg or two within, so I'm not sure if the last three are from the same hen.
Anyway, I'll try again in a few weeks, which gives the birds time to mature and for me to evaluate the offspring before rebreeding.