What are the causes of dead embryos before reaching Lockdown?

[Maiahr]

I am incubating and hatching quite a lot of eggs from various suppliers. I have noticed that eggs from some suppliers have way too many rotten eggs - embryo starts developing, then somewhere along the way it dies. No smell from the egg and NO blood ring. The embryo dies before reaching Lockdown. I am looking for articles that could help me understand what are the causes of these rotten eggs (dead and decomposing embryos) and alternatively what are the causes of the blood ring (which in my cases usually happens during the first week of incubation).
Thank you in advance

 

[featheredplanets]

Blood rings only happen in the first week, from what I read they’re usually caused by bacteria getting into the egg. Most embryo deaths are usually caused by the eggs being stored too long, improper pre incubator care, humidity too high or too low, not enough ventilation/air flow, incorrect temperature, genetic deformities, incorrect egg parent nutrition, infected/diseased egg parents.

This may help. If you Google your specific issue results will come up for similar issues on BYC and blog sites.

 

[Maiahr]

Thank you for confirming about the blood rings. Out of the 3 possible reasons for dead embryos from 6th to 16th days, the only one that would be the egg-seller's fault is

Infected embryos - either by infection from dams or external microbial contamination

Provide adequate ventilation of the hatcher room and proper openings of the hatcher ventilators.

How is it possible to have external contamination? Could the eggs be infected while in the incubator??