i like the tree at the edge. it's a cool shadow. i think this would look good as a very narrow crop. as wide as it is now but just as tall as the distinct line of the trunk. so you have the sheep and a bit of the tree hanging over them, and the trunk.
i was tempted to keep it in colour, as the sheep had almost psychodellic (*sp) dye all over them and it looked quite strange. In the end i plumped for the black and white because i preferred the high contrast.
I'll try and dig out the colour version and post it here