The West Country is an area of mainly mixed farming, so most of the barns also have accommodation for animals. The area is dominated by the great moors, the Mendip hills and the Somerset Levels. It is only in the latter where large scale arable farming was possible.
The links below on the left are to The “historic farmsteads preliminary character statement” for the south-west published by English Heritage. You can download them as .pdf files for reading off-line.