Cattle are being used to keep bracken and scrub land under control.
Young heifers are moving to a new area of Ditchling Common Country Park to improve the environment for wildlife.
In partnership with Plumpton Agricultural College, East Sussex County Council introduced grazing to the area in May for the first time in several years.
Grazing will continue until September and annually over the summer for ten years.
Notices advising people when cattle are grazing will be posted on entrances to fields and visitors are asked to take extra care if they enter.
The council says visitors can still walk through the fields where cattle are grazing, but dogs should be kept under control.
For information on the grazing scheme, call 01273 482670.