All persons furnishing material, supplies, or other articles necessary to the operation of any railroad company operated in this state and all persons having claims against such company for livestock killed by its engines or cars shall have a lien upon the property of the company for the amounts due for such supplies, material, or other necessary articles furnished within six months preceding the institution of proceedings to enforce the same, or for the amounts due to them for damages for the killing of such livestock. Such lien shall be superior to any mortgage or other contract lien created by the railroad company.