The point of having chickens, from this practical homesteaders point of view, is to have eggs/meat, compost, and a use for table scraps. For me it’s also enjoyment. If you eat pizza, you can feed the girls pizza scraps. It won’t go in the trash, that’s the important part. If they’re used to veggie scraps and not junk food, a feast of pizza may cause digestive upset for a day or so, but they will be fine. It sounds like a holiday leftovers sort of situation, so like the human body, they can detox if they’re eating healthy food normally. That’s the conclusion I came to after struggling with that question myself.