What actually is A1 and A2 milk?
Milk contains about 85% water. The remaining 15% is the milk sugar lactose, protein, fat and minerals. Beta-casein is about 30% of the total protein content in milk. A2 milk is the milk that contains only the A2 type of beta-casein protein whereas A1 milk contains only A1 beta casein or A1A2 type variant. A1 protein variant is commonly found in milk from crossbred and European breeds of cattle. A2 milk is found basically in indigenous cows and buffaloes
of India (Asia as a whole). A2 milk is branded by the A2 Milk Company like A2 Corporation and sold mostly in Australia,        New Zealand, United Kingdom and other developed countries.

History of A1 and A2 Milk
A2 beta-casein is the beta-casein from cows that have been
produced since before they were first domesticated over 10,000 years ago. It has no known negative effects on human health. In the past few thousand years, a natural mutation occurred which has resulted in a proportion of cows of European breeds producing a casein variant called A1 beta-casein. Slowly, these protein variant became dominant in milk which producing A1 milk. The gene encoding beta-casein was changed such that the 67th amino acid in the 209 amino proteins was switched from proline to histidine. This new kind of beta-casein that was created is known as A1 beta-casein which is found in the milk of many crossbred cows such as Holstein, jersey and Friesian

Exotic breed like Jersey,Holstein friesian, Ayrshire and British Shorthorn are A1 type milk. Milk from this breeds of cows that originated in northern Europe is generally high in A1 beta-casein.
Beta casein kills the pancreatic cell which produce insulin . which causes diseases like :
1)Neurological impairment, including autistic and schizophrenic changes
2)Type 1 diabetes
3)An impaired immune response
4)Autoimmune disease
5)Heart disease

Desi cow A2 type milk:
Health benefits with A2 milk intake which reduces
1)Autistic symptoms
2)Schizophrenic symptoms
3)The incidence of cardiovascular disease
4)Type-1 diabetes incidences
5)Neurological disorders viz behavioral disturbances, endocrine disfunction (diabetes, endometritis etc)
So far 40 desi cow has been registered . There are many more desi breed to be registered like Javari ,Kasaragod, Malaimadu, Nattumadu , Turupu, Alambadi ..