I find it interesting the difference in likes and dislikes of chickens... My Delaware, "Little", could care less for BOSS and scratch. My other chickens (different breeds) all LOVE BOSS and scratch! I only have one Delaware, so I wonder whether not liking BOSS and scratch is a breed thing or an individual thing?
I mix mine with cracked corn and whole oats, and give them a horse feed scoop a day scattered thruout the run. They peck the BOSS first....I think they must think they are ticks or something, they love them.
My birds will not eat sun flower seeds with the shell on. But they adore the hearts. I put a hand full on top of the yogurt they gobble up all come running when they see the bowl, Turkey's love love sunflower seed hearts. BOSS is great for horses too.