549.03 Sheriff to exclude from course vehicles and persons.—Every sheriff and every deputy appointed by her or him shall exclude from the course over which any race shall be about to occur, and at least 30 minutes prior to the starting thereof, all animals, vehicles, and persons, except those officiating or participating in such race, and their assistants, and shall keep such course free from the intrusion of any animal, vehicle, or person, except as above-provided, for a period beginning at least 30 minutes prior to the starting of such race and extending during the whole time such race shall be in progress.