if Cockerel with Pullets . . . No eggs yet, just thinking ahead. . .

[1TurkenLover]

said to be 3 months old:

if Cockerel with Pullets : No eggs yet, just thinking ahead, will all eggs be fertile ? How to tell ?

 

[Fred's Hens]

If you see him mounting, the eggs should be fertile. This happens when they are of age. I assume, although you didn't say with specifics, that it will be awhile? "All the eggs" is a different matter. A young rooster can only cover so many, somewhere around a dozen females. We rarely see 100% of the eggs fertile 100% of the time, but most of them are, most of the time.