For advice after wrapping the wing with vet wrap try to put a harness on to help keep the wrap and wing in place. Here's a link for a simple harness idea. https://www.wikihow.com/Make-a-Chicken-Harness?amp=1
I use this and probiotic for my ducks and chickens. I'll rotate between the two both have 22-25 mg of niacin. Which my chickens get it split between my baby ducklings and 3 chicken coops. I also use Purina for ducks for my ducks. Hope this helps.
This is what I have found so far. My ducks love kale, worms, minnows, small dried shrimp, dried mixed mealworms just need small pieces for ducklings. They do eat some spiders also. Hope this helps.
I give mine ground up rolled oats, meal worms crushed up, fruit, ECT with small rocks(for grit). I learned from my first chicks that if what you're giving them is to large they won't eat it. Maybe also trying cut up in dice size peices for your chicks when giving treats.
I've just started to raise chicks in April of this year. I've got a total of 53, 11 are 3 months the other 42 are a 1-2 weeks old. And still trying to figure out what kind of chickens I'll have.