I want to buy one for milk.

Punganur is a small dairy cow, but for milk business I would rather guide you toward Sahiwal, Gir, HF cross, or Jersey cross. Before paying, milk her in your presence, do a CMT test on all four quarters, and ask which month of lactation she is in. If she is in month seven or eight, yield will fall fast. For a cow above fifty thousand rupees, take a Pashumitra or vet with you.