Yup A2 milk is a brand, and currently the only brand screening their cattle to find ones that produce milk with predominantly the A2 beta-Casein. (some people are sensitive to the A1 protein, but not the original A2 that existed first.)

It's not organic, but all the organic milk on the market has predominantly the A1 beta-casien protein. So if protein intolerance is an issue A2 milk can be a solution for some people, although not all. Some have to avoid dairy all together.

We too could only tolerate A2 in our house, any other milk lead to diarrhea and eczema flare ups. Funnily enough DD1 has grown out of it and can now tolerate any kind of dairy.