It shall be and is hereby declared unlawful for any livestock to roam at large on the federal or state designated paved highways or highway rights-of-way of the State of Mississippi, except, however, that in those counties that have heretofore voted to come out from under the statewide stock law this shall only apply to U.S. designated highways, Mississippi Highway 55, and all paved Mississippi highways where said highways traverse more than one (1) county and connect directly with another paved highway in another state being extensively traveled by citizens of other states, and the rights-of-way thereof; and except also that this section shall not apply to any such highway or highway right-of-way or any type of highway or road located on any levee maintained by the Board of Mississippi Levee Commissioners or the board of levee commissioners for the Yazoo-Mississippi Delta through maintenance contracts calling for or permitting pasturage of livestock on levee rights-of-way.