I've had mozzarella from buffalo before; it was delicious! Hopefully your store simply ordered too much, and had to sell it quickly before it spoiled, and will simply order a little less next time. Very fresh food is really hard to order because it can be so difficult to gauge the demand at any time.
Anyway, your post has made me hungry for fresh mozzarella, but I like it with fresh tomatos, which are out of season now. (This may be some Americanization of Italian food, but it is really tasty!)