Prior to landing on a dirt road, the pilot overflew the area, noting a group of cows nearby. During the landing flare, the pilot observed a cow approaching the flight path from his left to right and attempted to maneuver the airplane to avoid a collision. Subsequently, the left main landing gear struck the cow and the airplane immediately veered to the left. Despite the pilot’s control inputs, the airplane continued to the left, landed hard, bounced and settled back onto the ground. Examination revealed structural damage to the left elevator, horizontal stabilizer and engine firewall.