About the grit in the crumbles, what would it be labeled as? Not that I doubt either of you, I'm just curious and want to see if it's in the crumbles I feed.
-Kathy
I have some the same age and I can tell which ones are boys or girls very easily. Maybe someone will post a picture that shows how to tell.
-Kathy
Edited to add:
I can't tell by the coloring, I go by the amount of barring on their back and wings.
http://www.vet.k-state.edu/depts/dmp/service/
And this is a thread I did on how to send them:
https://www.backyardchickens.com/t/799747/how-to-send-a-bird-for-a-necropsy-pictures
-Kathy
How did their navels look after hatching? If you're still in Illinois, you could contact these people and see about having a necropsy done.
http://www.agr.state.il.us/AnimalHW/labs/
http://vetmed.illinois.edu/vdl/
-Kathy