Having taken several courses in animal and human nutrition, I do understand the importance of nutrition. However, after reading the UC Davis paper on Vitamin A deficiency in poults, in my experience (admittedly, only one poult) the symptoms of vitamin a deficiency were not present, beyond "lack of coordination". I do give all my new hatchlings a vitamin/electrolyte/probiotic additive in their water, and maybe indeed it was that that "cured" my turkey and not the wrapping and physical therapy I did. I don't have a control case and I don't have the parents anymore, so I'll never know. In my Guineas, I have had a flipper in my last two hatches and followed the same treatment protocol. I'm considering not giving supplements or therapy to the next one to see if it makes a difference or not.
I know a higher protein content is needed for turkeys and gamebirds. However, with the flip over / vitamin a association in mind, the flock raiser that my chickens and older guineas and turkeys eat is higher in vitamin A than any of the gamebirds feeds I just quickly looked up. All I'm saying is that if it were really the cause of flip over, or the reason for not finding it in a particular flock, wouldn't you expect the Vitamin A content to be higher? To say you have never had it in your flock sound similar to people who use DE saying they have never had mites/lice/etc...What's to say you wouldn't have had it regardless, based on some other factor?