Thanks! Great ideas!
People report that duck eggs can taste funky/fishy if they are spending time at the pond, so I wonder if tuna or cat food would affect the taste of eggs? A lot of the protein in commercial food is fish protein anyway so maybe not.
I feed my adult layers a locally milled feed that is 21% protein and they do fine on it. I give them the high protein grower for the first couple of months only. So, something to keep in mind as you search is that the protein doesn't need to be as high if they are adult layers.