After Armin Arbeiter died in 1917 and the stock had dramatically been reduced during World War One, it was not until around 1925 that a sponsor for the Sulmtaler chicken was found in the person of Franz Koschar. The Sulmtaler chickens rode out World War Two at the breeding farm of Dornegg and had to be bred for egg production alone by order of the authorities. In doing so, their body weight and fattening capabilities were sharply reduced. In the rural stocks, though, they maintained a satisfactory weight. Already by 1945, in the region of Stainz, Oisnitz, Preding and Wieselsdorf, magnificent and heavy Sulmtalers were to be found in nearly every farm yard again.
A mere 12 years later, a devastating setback occurred: With the onset of industrial chicken breeding, the major breeding farm for the Sulmtaler in Dornegg was closed down and the province of Styria lost interest in the promotion of the local original breed, too. So not only the Sulmtaler itself but also the agricultural potential of this chicken breed fell into almost complete oblivion.