A2 Farm Fresh Milk What is A2 milk? Generally, cows have two kinds of protein, A1 beta-casein, and A2 betacasein. This single difference in protein has a big impact on the quality of milk. Desi breed cows produce quality A2 milk which is good for your overall health whereas European cows like Holstein Friesian, Jersey, etc. produce A1 milk which has been proven to contain BCM-7 that has been linked to causing undesirable health ailments when consumed for years together!.