The wildlife trust also keeps its own herd of Hebridean-cross sheep, as well as the Lincoln Red cattle.
Most of the cattle spend the year outside, coming in for shelter in winter and to calve.
“The Lincoln Red is one of the oldest and most traditional native cattle breeds, known for being both hardy and docile, so ideally suited to a life of conservation grazing,” the wildlife trust said.
The trust are expecting 18 calves to be born this season, which would match the same amount as last year.
The trust also works with different breeds of sheep and cattle, including Highland cows and ponies, to implement conservation breeding on some of its nature reserves.