Eggs behind in their growth

[ladymiller]

I have a friend hatching some chicken eggs for me. She has hatched before and she is really good with chickens. Now today is supposed to be lock down but she candled the eggs and sees movement in a lot of them but she thinks they are only around day 15. Should she start lock down? What would cause the stunted/slow growth. Advise?

 

[sumi]

If the chick embryos didn't develop as fast as they should've it most likely means the incubator temperature is too low. Tell your friend to double check the temperature.