It's a lovely shot, Carol. They're not dead center, but it wouldn't hurt to trim a bit more from the left side. More important would be to clone out that white wires as it does draw your eyes constantly. Just did that and no more distraction, and the cropping isn't necessary. Just so that makes more sense to you, the taller horse head was dead center, but angled in. The wires were roughly the same length on either side, centering the pair. Removing the wires tends to make the bulk of the two horses appear slightly more left, as the tall one is angled in with the heads more to the left side.
The reason why the sun sets in the evening is because it wants to see the sunrise in the morning. I rise in the morning because I want to see them both. RvdB
I see that Doug gave you your daily lesson on composition, Carol. If I live to be 1000 years old, I will never have his knowledge of composition. This shot looks like you ran it through ReDynaMix. I have found out the hard way that ReDynaMix and certain objects don't work well together. While it looks great on the wood fence, it can turn animal hides into a noisy mess. Other than that, the shot looks good although my personal preference is that borders of all sorts should be outlawed.