I have never had a BR lay a dark egg. They are almost always light brown. I did have one that was a medium brown, but mostly light.Anyone that has BR or BCM at what age do they start laying? I've gotten a pullet size dark brown egg twice now and no clue who its from. I checked the vents of both but they are both small and firm and since they are only 15 & 16 weeks old I really don't think its them. Their combs and wattles aren't red either. And Lucy's eggs (or what I think are hers are an XL size). My big girls have never laid such large eggs and their over a year old so I don't think they would just start laying bigger eggs. I know she's laying from looking at her vent. Maybe one of the big girls is laying darker eggs after not laying for a couple weeks?
They start at 20 weeks for production (Hatchery) birds.
It's not about the vent so much as it is about the pelvic bones. There are two sharp bones near the vent (I think it's pelvic?) anyway, fit two to three fingers held up to it and if it is two or three wide she is already laying, or soon to be laying.
Can someone please give me the correct terminology?