The article states, "... the action is largely limited to head-butting, heavy breathing and abundant slobber. Some bored bovines simply wander away."
There are drug tests, veterinarian monitors, and training. It's also a specific breed - Hérens. Apparently, they are big into establishing herd hierarchy.
Our cows aren't all the same. Some are definitely the leaders of the group - first to go to a new pasture, first to run up to the fence, first to do everything. The herd follows.
Some like people more than others. They rub up against you so much you want them to back off a little. Lots of slobber.
I see them butting heads out in the field all the time. They seem to be more playful than establishing hierarchy, but then again ... 'butting heads' has a negative connotation for a reason, right?
Of course, we have Holsteins, not Hérens. I watched the video ... Hérens are sturdy. They look more like bulls. Their fights are much different than what I see between our cows. Ours are a milking breed, theirs is a fighting breed.
Another funny thing ... this is Switzerland. Known for being neutral. But when you can turn a docile field of cud-chewers into fighting machines, what else are you capable of? Holy cow.