As long as this is NM-C it is fine.
ARTICLE 547 Agricultural Buildings
547.5 Wiring Methods.
(A) Wiring Systems. Types UF, NMC, copper SE cables, jacketed Type MC cable, rigid nonmetallic conduit, liquidtight flexible nonmetallic conduit, or other cables or raceways suitable for the location, with approved termination fittings, shall be the wiring methods employed. Article 398 and Article 502 wiring methods shall be permitted for areas described in 547.1(A).
I would be willing to bet NM has been used for years in these types of buildings.
The physical damage issue is entirely subjective and up to the inspector to decide.
ARTICLE 334 Nonmetallic-Sheathed Cable: Types NM, NMC, and NMS
334.15 Exposed Work.
In exposed work, except as provided in 300.11(A), the cable shall be installed as specified in 334.15(A) through (C).
(A) To Follow Surface. The cable shall closely follow the surface of the building finish or of running boards.
(B) Protection from Physical Damage. The cable shall be protected from physical damage where necessary by conduit, electrical metallic tubing, Schedule 80 PVC rigid nonmetallic conduit, pipe, guard strips, listed surface metal or nonmetallic raceway, or other means. Where passing through a floor, the cable shall be enclosed in rigid metal conduit, intermediate metal conduit, electrical metallic tubing, Schedule 80 PVC rigid nonmetallic conduit, listed surface metal or nonmetallic raceway, or other metal pipe extending at least 150 mm (6 in.) above the floor.
The inspectors in this area would pass this no problem it is neat, tight to the building surface and at least 6' off the floor.
Someone might hit it with a pitchfork
I think that is a big what if?
![[Linked Image]](https://www.electrical-contractor.net/ubb/wink.gif)
IMO this is a code minimum installation, sure pipe would be better but not required
