Oregon Revised Statutes Animals § 608.360

In every action for the recovery of the value of any livestock killed, or for damages for injury to any livestock, under ORS 608.340, proof of such killing or injury shall of itself be deemed conclusive evidence in any court of this state of negligence upon the part of the person, or the lessees or agents of the person, owning or operating such railroad. Contributory negligence on the part of the plaintiff in such action may be set up as a defense, but allowing stock to run at large upon common unfenced range or upon enclosed land owned or in possession of the owner of such stock shall not be deemed contributory negligence. In any such action, proof of willful intent on the part of the plaintiff to procure the killing or injury of such stock shall defeat the recovery of any damages for such killing or injury.