Up until recently, most of Indian farming depended on (and still does to a good extent) on Bulls ploughing the fields for seeding. That and bullock carts as transport.
That answers my question then - they get castrated and used for transport.
Bulls make more cows?
You only need one to impregnate lots of cows.
I wonder what happens to the male offspring of Cows in India?
not if you want a reasonably distributed gene pool, diversity of genes is always a good idea
Well, yes. You don't want one bull to do 100% of cows, but one bull can easily do an entire herd, and using In Vitro methods the most valuable bulls fertilise thousands of cows.