Heck Cattle are a hardy breed of cattle (Bos primigenius). They are the result of an attempt to breed back the aurochs, which became extinct in 1627, from modern aurochs-derived cattle.
The "Rieselfelder", near Münster, Germany.
There were two calves in this herd of cattle. One was just a few days old, I guess. The other one was a bit older, and very curious. At the first picture the older one is poking it's tongue out at us. ;) On the last picture, the older one is on the left, the younger one on the right.