Hi Joan,
Thanks for the information and the link. I did some reading after your 
email arrived. Variations of BCM in human milk are also thought to 
reflect food allergies in mothers.
There are some alternative explanation for these data that come 
immediately to mind, but I'll do some reading and try to "catch up" in 
this area.

On a practical level, I'm not aware of casein powders that declare the 
breed of cattle from which the casein was extracted. Thus, if we can't 
distinguish the source of the milk what difference does it make whether 
some milk might not cause the problems I outlined?
Best Wishes,
Ron