Mo. Rev. Stat. § 537.270

Whenever any livestock shall go in upon any railroad or its right-of-way, in this state, and the said railroad is not at such place or places enclosed by a good fence, on both sides of said railroad, such as is by law required, or where said railroad has failed to construct and maintain a good and sufficient cattle guard, or opening gate, such as is by law required, and such stock by being frightened or run by any passing locomotive, motor car, or other vehicle, or train on said railroad, shall be injured or killed by or because of having run against the fence on either side, or into any culvert, bridge, slough or mire, or other object along the line of said road, the railroad company shall pay the owner of any such stock so injured or killed the amount of the damages sustained.