Miss. Code § 69-13-7
If two or more adjoining counties shall at an election called pursuant to Section 69-13-1, vote against the state-wide stock law, then in such case, no fence or other barrier along the boundary lines of such county shall be necessary. However, in the event that two or more counties shall at such an election vote against the state-wide stock law, but an adjoining county or counties shall elect to remain under the provisions of the state-wide stock law, then the county or counties voting against the state-wide stock law shall, at its or their own proper cost and expense, before the provisions hereof shall become effective in such county or counties, build and erect and maintain along the line or lines of such counties a good and substantial fence or other sufficient barrier to prevent the intrusion of all such livestock mentioned in Section 69-13-1 as are permitted by the provisions of said section in such county or counties voting against the state-wide stock law, over, on, and upon the territory of the county or counties remaining under the provisions of the state-wide stock law. The fence herein provided shall be a fence satisfactory to and prescribed by the board of animal health, but no cattle guard or other obstruction shall be constructed or placed on any state highway. However, any infested county must provide watchmen night and day at such points to prevent cattle from passing through the gap where county fences would cross state highways.
Miss. Code § 69-13-7