A belt cover for attaching to a horse The belt cover including at least (1) an electrode for detecting a bioelectric signal by contacting with the surface of a body of the horse, (2) an electric wiring, and (3) a connector for connecting with the electric wiring through a part for connecting with the connector and the electric wiring. Each of the electrode and the electric wiring includes a stretchable conductor having a conductive particle including a silver particle and a binder resin. The stretchable conductor of the electrode and the electric wiring has a sheet resistance of 0.1Ω□ or less, an insulating layer is laminated on the electric wiring, and the electrode and the electric wiring are integrally formed without joints.