A2A2 milk: The type milk protein may be an important factor in digestion and overall health. The beta casein protein can come in a variety of forms that would be categorized as either A1 protein or A2 protein which is determined by the genes of the cow. Since the cow gets a gene from each parent she can either be A1/A1, A1/A2, or A2/A2. An A1/A1 cow will make only A1 protein in her milk, just like and A2/A2 cow will make only A2 protein it her milk. A cow that is A1/A2 will make both proteins in her milk, so there is not a dominant expression like other genetic inheritances. Once upon a time all cows produced A2/A2 milk however somewhere along the way it is theorized there was a mutation to the A1 gene. Humans and other mammals have A2/A2 milk. A1 may not be as digestible for some people as the A2 protein. Most of the milk in stores will have A1 or a mix unless they specifically sayttheir milk is A2/A2. Some people who think they can’t have milk due to digestion issues may actually do well on A2/A2 milk. Some of these people may say they can’t have cows’ milk but do okay on goat or sheep milk, again these people may have an intolerance to the A1 protein more so than which animal it came from.