For some reason, I'm leaning toward something environmental. What was the concentration of bleach water you used to clean it with? Did you let it dry thoroughly? Any air freshener used in the room they were incubated in?
Or it could be genetic. Were all the eggs out of the same rooster and hen? Adult hen or pullet? I would think for it to be nutritional, they'd have to be severely deficient somewhere. There are chickens who spend all summer eating nothing but grass and bugs that have no problems hatching a clutch of eggs with 100% survival of the chicks.
Or it could be genetic. Were all the eggs out of the same rooster and hen? Adult hen or pullet? I would think for it to be nutritional, they'd have to be severely deficient somewhere. There are chickens who spend all summer eating nothing but grass and bugs that have no problems hatching a clutch of eggs with 100% survival of the chicks.