cow shed; cattle barn
A building or structure for housing cattle; used in agricultural contexts.
The farmer built a new cattle barn.
牛舎 refers specifically to a building for cattle, whereas 畜舎 is the broader term covering barns for any kind of livestock.
牛舎 (ぎゅうしゃ) houses cows, but 厩舎 (きゅうしゃ) is a stable for horses; the similar sound and shared 舎 kanji make them easy to mix up.
Used because a 牛舎 (cowshed) is counted as a building.
Compound of 牛 (gyū, 'cattle') and 舎 (sha, 'building, shed').