orpington hatching eggs

[danielleparry]

hey, ive got 50 eggs in the incubator at day 7 , 35ish cream legbars, the rest are a mixture of barnvelders, marans, and orpingtons.
nearly all of the cream legbars are growing lovely, one or two of the marans and barnvelders, but absolutely none of the orpingtons,
I've got the eggs from various local breeders, they all have eggs in their incubators and hatching chicks,
I would have blamed the eggs not developing on me and it being late in the season if it wasn't for the cream legbars doing so well
so I was just wondering if maybe it harder to see development, or if develop slower, or is there another reason,
I just cant see why no orpingtons are visibly developing when the clb are,
and if they magically do start to develop will they have a later hatch date?

 

[Pyxis]

Could be that the orps aren't fertilized at all. They can have problems with this because they are so fluffy - the feathers and fluff around the vents can block fertilization.