9 C.F.R. § 50.18 – Identification and disposal of cattle.

(a) All dairy cattle disposed of under this subpart must travel from the premises of origin to their final destination with an approved metal eartag, supplied by APHIS or the State representative, bearing a serial number and attached to each animal's left ear.
(b) Dairy cattle disposed of under this subpart must be shipped under permit either:
1. (1) Directly to slaughter at a Federal or State inspected slaughtering establishment; or
2. (2) Under permit directly to a livestock market and, under the supervision of an APHIS representative or State representative, through a livestock market pen that is dedicated to and marked exclusively for use for animals moved to slaughter, and then directly to slaughter at a Federal or State inspected slaughtering establishment.
  (Approved by the Office of Management and Budget under control number 0579-0193)