Possible just not very comfortable or all that practical. Cows don't learn the finer points of riding like horses (or even too much of the basic parts) and their backs don't lend themselves to it quite as well.
Thanks for info everyone! and thankyou SpringChickens for that video!! If I buy a male calf (which I probably will since im going to be buying the calf straight from a dairy) will the male calf need to be castrated?