There are many domesticated animals that graze including sheep, goats, horses and of course cattle - however all graze in different ways.
On Brill Common, cattle are ideal for removing long coarse grass. Their broad mouths make selective feeding impossible and so they cannot selectively eat flowering heads of herbs in preference to scrub, unlike sheep. This generalised feeding behaviour is a valuable asset for maintaining species biodiversity in grassland such as Brill Common.
Cows are social grazers so tend to group together, a helpful behavior when they need to be collected together by the volunteers for moving or TB testing. Without the aid of a sheepdog, sheep would be far less co-operative.
Cows dung in discrete cowpats and over time have adapted their grazing pattern to avoid these, leaving random scattered tufts of longer grass. These produce localised 'microclimates' suitable for a wide variety of species to colonise.