Yes they love fish and some feed manufacturers use it as the main source of protein in laying mash. Problem is the taste of the fish can transfer to the eggs if they get too much of it. Same thing happens if they get too much crushed oyster shells or cheap grit. Some folks don't mind the taste in their eggs but personally if I want fish in the morning with my breakfast I will have fish not eggs that taste of it. So go ahead and feed them some fish but don't overdo it.