This is quite a different approach to animal photography. I like the way the horse becomes part of the picture and still captures the eye, without beeing the main object of the photo. The fence is a bit distracting for me, but it certainly acts as a sort of frame. A very nice photograph!
The horse was watching you take the photo. If I'm not mistaken, the horse looks like it is expecting a colt. Maybe you could get a photo of the little one and the mother together.