You've suffered from poor light for this shot. While the exposure is technically quite good (full range from white to black) it appears quite anaemic. The horse lacks definition because of this.
I would suggest that you should have got much closer, since the context has very little relevance. As David Bailey once said: "get in position and ready to take the shot, then take three steps forward".
This photo would have lookes so nice from another angle, a little more detail of the horse's face would have been really nice. I like the contrast of colors though
the horse does not really pop out of the image, more bokeh would be better I think. composition: the horse looks cut off, it's legs are about to come into the frame but just don't