My ten year old chickens are still laying every day and one just hatched out four mystery chicks (we don’t have a rooster lol) They don’t like chicken feed so they eat very little of it. They free range usually but the hen with chicks is eating the chick starter with her chicks now. I feed them completely random scraps, bread, BOSS, whatever I have that they seem interested in trying.
You could always just give them some sardines or actual fish, or scrambled eggs. Mosey is much more scientific about chickens than I am (we know this about each other lol) so in a spot with limited choices I thought I’d mention the canned fish option. My mom gives her chickens a little ball of hamburger every day too. We’re the chicken weirdos.