The Heck or Munich-Berlin is a German breed or type of domestic cattle. It was bred in the 1920s by Heinz and Lutz Heck in an attempt to breed back the extinct aurochs. Controversy revolves around methodology and success of the programme. There are considerable differences between Heck cattle and the aurochs in build, height, and body proportions. Furthermore, there are other cattle breeds which resemble their wild ancestors at least as much as Heck cattle.