21 CFR §225.110

1. (a)Distribution records permit the manufacturer to relate complaints to specific batches and/or production runs of medicated feed. This information may be helpful in instituting a recall.
2. (b)Distribution records for each shipment of a medicated feed shall comply with the following provisions:
   1. (1)Each distribution record shall include the date of shipment, the name and address of purchaser, the quantity shipped, and the name of the medicated feed. A lot or control number, or date of manufacture or other suitable identification shall appear on the distribution record or the label issued with each shipment.
   2. (2)The originals or copies of the distribution records shall be retained on the premises for not less than one year after the date of shipment of the medicated feed.