Go give it to them and watch and see...............my flock is my 'kitchen disposal'.
The girls have crumbles in front of them all day long, the bugs/seeds/whatever they can catch/scratch up in their run during the day, whatever treats I bring out for them that day and then I let them out to free range for about an hour before dark, while the dogs are in the house!!!
What I'm gettin' at is.......if your flock is well fed........whatever treats you bring out for them, they will decide what is good or NOT........chickens won't usually eat something that is BAD for them, UNLESS they are underfed and super hungry, they won't go for JUST ANYTHING that is put in front of them, if they are happy well fed girls.
I've seen my girls catch and eat baby mice, snakes, crickets, grasshoppers, spiders.........all protein.........makes those eggs taste better.
I've always looked at it like........if I ate it, and didn't die, then my animals can have the left overs. Small amounts of 'people food' treats can be good for you flock.