I was told ACV in drinking water. It does seem to help. When my littlest littles were doing poorly I gave them crumbled boiled egg yolk. I also found a recipe somewhere here consisting of 2 parts chick starter, 1part corn meal, 1 part oatmeal and 1 part mealworms. Grind all together. My personal experience tells you to grind oatmeal first alone, add starter and mealworms and grind again then stir in cornmeal since it is already ground. I put parakeet grit in with this.
Here's one of my smallest serama chicks next to a Leghorn chick. The serama's about the size of a quail. It doesn't seem as healthy/active as the rest, so I've been taking it out a few times a day for a little extra feed time. This morning, it's got pasty butt. Aside from the cleaning & TLC, is there something to add to the food to help this one out?