is a trademark
of the A2 Corporation, which is licensed by milk
distributors to apply to cows
' milk which has been tested to ensure it contains a higher proportion of A2 type β-casein
than regular milk. The A2 Corporation has developed a test, where DNA
from a cow's tail hair is examined to determine whether the milk they produce will be high in the A2 protein
. Milk producers can test all their cows, and separate those that produce A2 milk from those who do not. Milk identified as "A2 milk" is currently available in New Zealand
and select locations in the United States
About a third of the protein in cows' milk is β-casein and there are several forms of it.
Directly from the A2 Corporation website: "It was recognized that this statistical correlation was not, in itself, proof of a beneficial effect..."