An animal’s genotype can only be determined via genetic testing, which is currently available nationally through Holstein Canada.
More about A1 and A2 milk
A cow’s ability to produce A1 or A2 milk is entirely dependent on her genetic make-up and it is impossible to feed or manage our way to more A2 milk. Dairy animals possess a genotype expressed as either A1A1, A1A2 or A2A2, with each copy of the beta casein allele leading to the production of the corresponding type of beta casein. A2A2 cows are the only ones that can be considered producers of “A2 milk” since A1A2 cows will produce milk with a mixture of A1 and A2 beta casein.