Most regular cows’ milk brands today contain a combination of two main types of beta-casein protein, namely A1 and A2. a2 Milk® is special because it is an exception to this. What makes a2 Milk® different to regular fresh cows’ milk is the absence of the A1 protein. It is the A1 protein that many people seek to avoid by switching from regular cows’ milk to a2 Milk®. The a2 Milk Company uses comprehensive herd selection to choose cows which don’t produce the A1 protein.