That's not sufficient for gamebirds.. it needs to be
higher protein gamebird starter.
Angel wing is not a thing as far as I know in guineas. It looks like a weird stage (some have a growth spurt) or also like the feather sheath just hasn't come off yet.. presuming it hasn't been pecked opr plucked by others, best I can tell from the photo.
https://meyerhatchery.zendesk.com/h...to-Raise-Guinea-Keets-from-Arrival-to-Outside
Guinea keets need a 24-26% protein turkey or game bird starter. It comes in at 30% protein Purina game bird and turkey starter in my area.
Hope this helps.. FWIW feathers are made from 90% protein AND it's amino acids..
Hope this helps!