I personally witnessed a fight between two raging mad bulls in western Utah last year that resulted in a hit so hard, it literally took out a huge chunk of skull plate clear to the eye socket! The bull acted very crazy after that, running around in circles shaking his head. There is no doubt he didn't survive a hit like that for very long, you could actually see his brain! Nature sure can be cruel sometimes, thanks for sharing your picture, it must be a common thing.