Abstract: A frontal pasture system utilizes a mobile wire fence provided with a lower insulated wire and an upper electrified wire. The animals contained by the system can push on the lower wire to displace the fence. The upper wire is electrified to contain the animals within the boundary of the pasture front. The system utilizes a frame having a sliding base and a regulating mechanism for preventing differential displacements of the fence with respect to the guide wires. The regulating mechanism comprises an arm mounted on the base and having a freely rotating wheel contacting the earth. A locking device acts on a stop causing teeth on the wheel to dig into the ground. The arm pivots about the point at which it is joined to the frame raising the rear portion of the frame from the ground. In an alternate embodiment the locking device comprises two arms joined in a scissor-like fashion.