[flangey]

Hello, I've been breeding my Mini Appleyards for a couple of years now, but this year I'm having a nightmare.  I'm doing nothing different from previous years, my flock are all unrelated (I have three breeding trios), but my babies are getting to three or four days before hatching and dying in their shells!? I'm not just talking one or two, I'm talking 30 eggs so far!  Has anyone got any ideas at all?  Is there some horrible disease I'm not aware of that could cause this?
Any advice would be greatly appreciated 

[rileyfin]

Could possibly be down to bacteria  in the incubator, conditions are ideal for it and it just takes a little on your hands or in the water for it to take hole. 
Do you use water from the tap in the incubator, this could also cause problems because of the additives. Sometimes the waterbords seem to vary the additive strengths.
Hang in there, and I would give the incubator a good disinfecting when the eggs are finished.

[niccigroves]

I had this problem and was advised that the membrane inside the egg dried out too much so the duck couldn't pip through. I was advised to spray the eggs every time they were manually turned with warm water as humidity needs to be higher than chicken eggs to stop the shell and membrane from drying out. I only had 1 out of 12 eggs actually hatch on its own the others died trying to break through :{ Hope this helps.