Chestnut - a horse portrait

My forum's Monthly Drawing Project for April is a photograph of a horse. I know nothing about the horse other than I saw it lying down on a bed of straw as I walked near the Grand Union canal one cold and frosty January morning.

I'm quite pleased with my effort to draw him in pencil but I recognise two significant mistakes in the composition. I shouldn't have drawn the whole of his body and I shouldn't have tried to draw the straw he's laying on. The 'project' really calls for us to be loyal to the photograph, and that was therefore my first consideration, but as a portrait, artistic licence would have been better served by drawing his head and shoulders only, I think.