Hello Colleen,

> I am not sure, but could probably discuss with my collegues and get back to 
> you.  I am not sure there would be a difference, as the casein and whey 
> proteins would be found in both.  I cannot think of a medical reason why it 
> would matter which was used, but on the same note, is there some reason you 
> prefer to use yogurt rather than milk?

Are the proteins the same in raw and sour milk (yogurt, etc.)?

If not, yogurt may be easier on her immune system (we're not about to start giving her raw milk anytime soon)

Even if the proteins are the same, yogurt may be easier on her digestive system.

On the other hand, I may be talking out of my elbow...

Best wishes,
Alex.