铁丝网
Barbed wire fences cannot effectively contain smaller livestock such as pigs, goats or sheep. Where these animals are to be fenced, woven wire is used instead, sometimes with one or more strands of barbed wire at the top, and sometimes at the bottom to prevent animals from pushing under. For swine, a ground-level barbed wire strand or electrified wire is used as well to prevent digging beneath the fence.