If your birds are not laying yet, the excess calcium in the yogurt can actually hurt them. if the feed has some probiotics in it then you really do not ned the yogurt. I would switch the Poly to a poultry vitamin. Sav-A-Chick, whatever, rather than the human vitamin. some of the hiamine, which the Corid blocks, is absorbed no matter what. After the 7 day treatment with the Corid, a good poultry vitamin, as well as a probiotic, is the best thing to do for a few days. [3-4 days] Giving a vitamin supplement, with the Corid, is defeating the purpose.Thank you so much everyone! I messed up and I would feel horrible if I hurt them. I have some Poly-Vi-Sol to give them after treatment. I got some regular yogurt for them as well. Will the yogurt be ok for a probiotic or is there something else I should give them? I know their food also has probiotics and in it.