Measure of Purity
Pure breeds of the Bos Indicus variety have been genetically proved to produce A2 milk. The most prominent breeds of these cows in India include Gir, Sahiwal, Red Sindhi, Ongole Guntur, Deori, Tharparkar, etc. These cows are also referred to as ‘Desi Cows’.
Prominent features of Desi Cows
All Desi Cows contain a prominent hump that encloses a central vein also sometimes called as ‘surya ketu nadi’.
This is prominent specific fold of skin below neck which is prominently present in all Desi cows
The backs of most Desi Cows are rounded, while those of exotic breeds are sharp and angular.
Desi Cows have round and prominent foreheads, while those in the exotic cow breeds are flat or almost flat.
Impact of Crossbreeding on Purity
Cross breeding is the process of breeding an exotic cow breed with a desi cow breed. During the Milk Revolution, the process of crossbreeding played a pivotal role in increasing the yield of milk. However, it has affected the quality of the yield such that cross bred cow display some or all visible features of a Desi cow but produce A1 protein milk or a mixture of A1 & A2 protein milk.
Ergo, it is nearly impossible to predict the type of milk through simple inspection.
DNA Testing is the Only Solution to Identify A2 Protein in Milk
A cow's genotype (whether it can produce A1 or A2 milk) can only be determined via genetic testing. Since the beta-casein protein produced by dairy cows in their milk is a genetic trait, the type of beta-casein that cows produce will not change during their life. The only scientific way to know whether milk contains A1 protein or A2 protein is conduct a DNA test on the milk.
All about A2 Milk