How do I tell if a chicken brown egg is fertilized?

Question

I can't see thru the brown eggs by holding them to a light.

any other way to tell? We have a hen who sits on her eggs and fights us but after about 4 weeks, we took them away from her. Anyway in the future to tell? should we mark them with a marker?

any advise would be nice

Thank you

Answer 1

What you need to remember is unless you have a very good candler you will need to test the eggs before they are 10 days old. Usually by the time they are ten days in there are enough veins and the mass of the embryo is enough that unless  you really know what you are doing and experienced then it is hard to tell. I like to test at 5-7 days old. Then I don't do anything until I move them into the hatcher for the last three or four days because they  need higher humidity and no turning.  

Answer 2

hi,hold them up to a BRIGHT globe at night,shading your eyes from the globe and you WILL see a small smudge inside ( fertilised ) the key is a strong globe,at least a 100 watts.--cheers--