How do i get my horses mane to grow back?

Oh my goodness, I would cry if someone did that to my horse! I know there are some pretty cheap-ish products that you can get which claim to help grow it back, but I think time will be the main factor.. Don't worry though, it will grow back to it's former glory.. i once rescued a horse that had it's mane basically shaved off for some unknown reason, and within a few months of having him, it had grown a good 8 inches..megatrek rebuilder is what i used. good luck!!