There is a fascinating discovery of the difference between the A1 beta-casein variant, and the A2 beta-casein variant, as chronicled in the book “The Devil in the Milk” by Kenneth Woodward. Some line of cattle have A2 capability, but most have A1. Since it is a double allele thing, the possibilities are 100% A1, 50-50 A1 A2, or 100% A2. A2 milk is the ideal, which goats produce exclusively, but it can be bred into lines of cattle. BCM7 is the “devil” in our milk.