It might surprise some farmers to learn just how strongly dairy cows are driven to groom themselves; but in fact, this is a completely natural behaviour that cows share with many other animal species, often tied to their deeply-rooted biological needs for comfort, stress relief, and overall wellbeing.
A 2018 study by researchers at the University of British Columbia (UBC) found that dairy cows work just as hard to access a mechanical brush as they do to access fresh feed. With food motivation is the benchmark for measuring how important a resource is to an animal, the fact that brush access was rated equally in the controlled experiment says a great deal about the importance of grooming to them as a natural need[i].