Why are there farm animals in our National Parks?

(L-R) Michael McDonagh, National Monument Service (NMS) chief archaeologist, Malcolm Noonan Minister of State for Heritage, Niall Ó Donnchu Director General of National Parks and Wildlife Service, and Minister Darragh O’Brien Minister for Housing, Local Government and Heritage at Dowth Hall on the occasion of the announcement of the State purchase of Dowth Hall and demesne and the establishment of Ireland’s 7th National Park. Picture: Maxwells Map: Nationalparks.ie
What comes to mind when you think of a National Park? Great expanses of wilderness? Areas with the highest levels of protection for nature? Places where wild nature can be enjoyed in its purest form?
I imagine that most people do not associate the idea of National Parks with farming and farm animals — don’t we have plenty of space for that already?