Chickens don't care if it's chicken... so I don't worry about either. It's not like they're going to have psychological issues over it. As long as the protein came from healthy animals... it could be ground up unicorns for all I care.
I notice the Dumor crumbles often has a lot of dust in it and sometimes it looks like it didn't get mixed quite right.
I now mostly use AgMaster which is Farm and Fleet's label. It's usually cheaper and a bit more consistent.
I have a label here from the Dumor layer crumbles. It lists...