Well, I must admit I'm surprised. Here is Dr. McCrea's response to my inquiry as to whether yogurt is included in her definition of "dairy products" and after I told her I've read all kinds of recommendations to use yogurt:
"Poultry do not produce the enzyme Lactase and therefore cannot digest the sugar Lactose. All dairy products contain Lactose, including yogurt. Yes, there are beneficial bacteria, but they are designed for humans, not poultry. You will still induce diarrhea and that will not allow the "probiotic" bacteria to attach and perform many of the beneficial functions that we humans enjoy. This is yet another case of people not consulting with their poultry specialists. Stories are spread via the internet and hearsay that are not based upon scientific fact. Always consult with your state poultry extension specialist or poultry extension veterinarian. As for Doc, you may need to post on his section for him to get your question."
I am now going to post an inquiry for Peter Brown to read those responses and let me know if he agrees.
God Bless,