Following the 2007 release of the book Devil in the Milk by Keith Woodford, there has been growing concern expressed by the general populace about A1 and A2 beta-casein content in milk.

A2 beta-casein is the beta-casein that cows have produced since before they were first domesticated, over 10,000 years ago. It is considered safe and nutritious and has no known negative effects on human health. Sometime in the past few thousand years, a natural mutation occurred in some European dairy herds that changed the beta-casein they produced. The gene encoding beta-casein was mutated such that the 67th amino acid in the 209 amino acid chain that is the beta-casein protein was switched from proline to histidine. This new kind of beta-casein that was created is known as A1 beta-casein, and is generally more common in many of the big black-and-white cow breeds of European descent such as the Holstein and Friesian. Due to their size, milk production, and demeanor, these breeds of cow are used to produce the vast majority of Northern Europe and America’s milk.

The cause for concern with milk containing A1 beta-casein is that the 67th amino acid switch from proline to histidine readily allows a digestive enzyme to cut out a 7 amino acid segment of the protein immediately adjacent to that histidine. When proline is present in that location (as it is in A2 beta-casein), that same segment is either not separated at all or the separation occurs at a very low rate. The 7 amino acid segment that is separated from A1 beta casein is known as beta-casomorphin-7, often abbreviated as BCM-7.

BCM-7 is the real “devil” in A1 milk for a number of reasons. It is an exogenous (doesn’t naturally occur within the human body) opioid that interacts with the human digestive system, internal organs, and brainstem. While no direct causal relationships have been demonstrated between BCM-7 and these diseases due to a wide range of contributing factors for each illness, BCM-7 has been linked to type 1 diabetes, heart disease, autism, and other serious non-communicable diseases as well.

  The good news:
We at Houston Mountain Ranch learned about the A1/A2 issue by reading Keith Woodford’s Devil in the Milk.  We are proud to offer 100% A2/A2 raw milk and customized dairy products as 
yet another example of our wholehearted commitment in providing you, our shareholders, with natural, real, fresh, local food.
  For Further Reading:
Here is a general synopsis by Dr. Thomas Cowan of The Devil in the Milk by Keith Woodford which examines links between A1 milk and a wide range of health issues. is a link to Keith Woodford’s blog, specifically listing all of his posts regarding A1 and A2 milk and related topics. and are both thorough collections and discussions of scientific literature regarding beta-casein, its variants, beta-casomorphin-7 (BCM-7), and links between BCM-7 and several non-communicable diseases.

A2/A2 Raw Milk Herd Share Program

ouston Mountain Ranch, LLC


5473 CR 320 Rifle, CO, 81650

Colorado Meats, Milk and Honey

About A1 and A2 beta-casein in cow’s milk:

Our 3rd generation family ranch runs a Raw Milk Herd Share Program.   This is the only way to obtain nutritious raw milk in Colorado unless you own and milk your own cow.  Our A2/A2 Jersey cows are all grass fed on rotating pasture.  In winter, they are fed Certified Organic Grass Hay.  We have fresh spring water running year round through the herd’s pasture that has been tested clean and free of dangerous bacteria or other contamination.  We are proud to be members of the Weston A. Price Foundation and Farm To Consumer National Organizations.  We are also registered with Colorado’s Dept. of Public Health & Environment, and our milk is tested regularly at the Colorado State University Laboratory in Boulder, Colorado.  

Also available to Herd Share Owners are customized raw dairy products such as our Raw Sea Salted or Unsalted Butter, Kefir, Yogurt, Buttermilk, and Sour Cream, Ghee and cheese.