Cows, like dogs and people, like a good scratch. Outside, they’ll rub their bodies against fence posts or trees to remove parasites or just stay clean. Some do it so much, they can break radio transmission towers if you don’t fence it off .

But many dairy cows in the United States never go to pasture . And even when they do, cows may spend winters tied up in a barn. So if a cow has an itch to scratch — what’s a cow to do?

In a lot of places, nothing.

But in some places, there’s the mechanical brush.