Why egg shells staining yellow during hatch?

[Alaskaduck]

Hello, today is day 28 and 4 of my 8 duck eggs externally piped today. On some of them, the pointy end is turning yellow on the outside. Is that normal?

 

[Hybridchucks]

pic?

 

[BlossomChicks]

Same here on call duck eggs that are 28 days today too. Not yellow but a bit darker above air sack line.

 

[Hybridchucks]

A picture would help!

 

[Alaskaduck]

I think I'd have to take the whole egg out to get a decent picture. Hesitant to do that when they're piped.

 

[Hybridchucks]

yeah thats true....i hope things go well....keep me posted

 

[Alaskaduck]

5 progressing but they sure are slow...stressful. But tiny advances on zipping every few hours

 

[Alaskaduck]

Same here on call duck eggs that are 28 days today too. Not yellow but a bit darker above air sack line.

Interesting, the staining I see is in pointy end. But the ones that have piped are slowly, so slowly progressing.