What is buttermilk exactly? Sry, sounds like a good idea.You can give them buttermilk mixed in feed for a couple of days. It is easily absorbed and doesnt pass through their system like yogurt. It also strengthens their immune system. In one month dose them with the safeguard 5 days in a row in the mornings before feeding. Then wait 4 hours after worming and then feed them. Then give them buttermilk mixed in their feed for a couple of days. You can add chopped boiled eggs to the mixture if you wish. Your chickens will scoff it up. This should clear up shed intestinal lining while providing buttermilk as an easily absorbed probiotic.