A1 cows were a recent genetic mutation in the 1940s which yielded slightly higher quantities of milk so became dominant in the US. https://a2milk.com/find/ I use cultures to make A2 milk into cheeses at home. - http://www.cheesemaking.com/Quark.html http://www.siliconinvestor.com/public/4188495_d150e8c269c53dcddfc8305dbb15daf6.jpg