Of course you can.....I toss out an apple for a game of Chicken soccer......I toss out scratch under the trees as they free range.....I feed squash...I only do it once a week.....I call it Sunday, fun day.....All my animals get treats on Sunday....I am always home, no company and it is just the day I treat them...Horses eat apples and carrots, dogs get a chew bone and the Birds get a treat of veggies or scratch.....I have healthy happy animals......You can give your chickens treat,Just in moderation.
Cheers!