The provisions of this act shall be construed to apply to the transportation upon public highways of carcasses and refuse, from packing houses or other points of origin to disposal plants or substations. The term “refuse” as used in Kan. Stat. Ann. §§ 47-1201 to 47-1220, inclusive, or any amendments thereto, shall include offal, bones, suet and meat trimmings. The provisions of this act shall not apply to disposal plants operating under the supervision of the United States bureau of animal industry, meat inspection division, or those licensed by the secretary of health and environment, meat inspection division, and processing only packing house refuse received from a packing house operated by the same person or group upon contiguous premises.