nestle - doing A2 infant formula, page-59

asking me, I assume?? it's the ABSENCE of a1 beta casein. There are several protein types in mammal milk, a2 beta casein is fairly ubiquitous, and a1 beta casein is a fairly recent evolutionary mutation occurring (afaik) only in some breeds of cattle that produce both types - and pretty much after you neutralise the enzymes that would help digest this (if you were a calf) the a1 beta casein has adverse reactions in human gut biome, compared with fairly neutral reaction for milk when no a1 is present. articles all over the webs, the a2 milk co latched onto this years ago (yes pun intended) and forms the founding premise of their milk formulation and infant formula and other products since, and their premium price charged, and premium price paid to farmers, and associated company success... etc.
I'm so thrilled to see the new label bottles hit our local supermarkets in SE Melbourne last weekend - that alone will help clear things up a bit on this front.