I adapted this recipe from one give to me from one of the real old timers in the chicken field. It has saved more than a few of my birds.

Ingredients:
1 cup of crumble feed. This can be layer crumble, chick starter, or medicated chick starter (but not if any game birds will have access to it). If I am feeding to just chickens or chicks, I use the medicated chick starter, I figure it is one more base covered on possible causes for illness.
1 cup of yogurt. I use plain non-fat yogurt, I figure the birds don’t need the added processed sugar.
1 cup of Buttermilk.
1 tsp. Apple Cider Vinegar. Raw is best, but I frankly use what I have on hand.
1 tsp. Garlic Powder.
1 tsp. Food Grade Diatomaceous Earth. I stress Food Grade.
1 tsp. Powdered Sea Kelp.

Directions:
Mix all together and let set for a few minutes for the dry feed to absorb the liquid. If it sets up too thick, you might want to add a little water before you give it to the chicken(s). Allow them to have as much of this as they want. I usually also offer portions of hardboiled egg, but don’t allow them to eat the egg exclusively. Refrigerate what you don’t use for up to 2-3 days. This is perfectly okay to feed to healthy birds, so if there are left overs after a couple days, they can go to the rest of the flock.