The morpho-lexical type Barn is found in Bavarian and Alemannic dialects of the Alpine region. While within the Crowd documents, forms of Barn only have the meaning 'fodder manger, rack for fodder, fodder trough', atlas examples are attested with the meaning 'hay room, compartment for hay above the cattle shed' (cf. VALTS IV 110).
In Kluge's etymological dictionary, only the first meaning 'manger, hayloft' is given in the sense of a feeding vessel. In other dictionaries, however, the definition as a part of a building in which fodder is stored is also given (cf. BWB, DWB, Idiotikon). The noun barn also exists in English as "A covered building for the storage of grain; and, in wider usage, of hay, straw, flax, and other produce of the earth" (cf. OED).
In German, the etymology of the word seems uncertain. The Etymological Dictionary of the German Language considers a connection with gem. *ber-a- 'to carry'. This probably includes the Old English (ae.) beren or bere-ærn, the ae. bere 'barley'. However, there is no German equivalent for the latter.