The animals have been given access to part of the Woodland Trust's Glen Finglas estate in the Trossachs for the first time since it was planted 15 years ago.
They cause minimal damage to the young trees and their hooves are perfect for breaking up ground, allowing seeds to take root. They help maintain healthy ground flora by grazing on coarse grasses and trampling bracken to keep them in check. This can help to reduce the risk of grass fires.
Phil Gordon, estate manager at Glen Finglas Estate, said: "As long as a healthy balance is maintained, grazing and expanding native woodland can run hand-in-hand. Trees provide shelter and shade for the livestock, and cattle are naturally designed to keep other vegetation down and break up the ground.
"The ancient upland wood pasture at Glen Finglas is recognised as one of the best examples in the in the UK. We're now working to create the wood pasture of the future, and allowing cattle in to graze the woodland is a key part of this process."
Glen Finglas forms part of The Great Trossachs Forest, a restoration project covering 61 square miles.