Aha! Just as I suspected: the cows were an attempt to re-create the aurochs. The aurochs were huge, aggressive wild cattle that were the origin of cattle as we know them, but larger, dangerous, bad-tempered and far nastier and hunted by cave men. Those 'cows' in cave paintings? Those were aurochs.
http://www.ibtimes.co.uk/aurochs-how-hitler-goering-resurrected-extinct-species-make-nazi-super-cows-1482161Aurochs, or Bos primigenius, died out in 1627 in Poland. They were a large breed of cattle, standing up to 1.8m in height, and was ancestor to modern domestic breeds. Aurochs had huge curved horns that characterised the breed – in some the horns could reach 80cm in length – and their legs were longer than modern cattle.
Historical accounts suggests the beasts were fast and very aggressive. They were not afraid of humans, and if they were hunted would attack back in response.
...In the 1930s, Nazi second in command Hermann Goering asked geneticists Heinz and Lutz Heck to re-create the extinct species. A keen hunter, Goering instructed them to develop a genetically engineered species by back-breeding from auroch descendants.
African Buffalo are some of the most feared/respected big game. Aurochs were on that scale.