Quote: I don't know anything about Dorkings etc and late hatching. But if the eggs are cold at first or the bator is just a tad cool...they may take longer. Shipped eggs can take longer too. Lot of things can effect hatch time and rates.. temp high or low, nutrition, size of egg, breed, stress of shipping, and more. I have read that if you select for early or late hatchers it will pass on. But selecting over time for either early or late hatchers could cause chicks to become weaker.
My last few hatches have had some early hatchers...I think my bator is starting to run a little hot. Either that or the fact that i had broody hens giving the egg a little "head start" by sitting on the eggs in the nest box. I collect more than 3 times per day when selling hatching eggs. But most of the eggs I sometimes sit in the nest box for a whole day.
Trisha