SDCL § 39-14-46: Adulteration by poisonous or deleterious substances.

A commercial feed shall be deemed to be adulterated if it bears or contains any poisonous or deleterious substance which may render it injurious to health; but in case the substance is not an added substance, such commercial feed shall not be considered adulterated under this section if the quantity of such substance in such commercial feed does not ordinarily render it injurious to health.