21 C.F.R. § 556.720 – Tetracycline.

(a) Acceptable daily intake (ADI). The ADI for total tetracycline residues (chlortetracycline, oxytetracycline, and tetracycline) is 25 µg/kg of body weight per day.
(b) Tolerances. The tolerances for the sum of tetracycline residues are:
1. (1) Cattle and sheep.
  1. (i) Kidney and fat: 12 ppm.
  2. (ii) Liver: 6 ppm.
  3. (iii) Muscle: 2 ppm.
2. (2) Chickens and turkeys.
  1. (i) Kidney and fat: 12 ppm.
  2. (ii) Liver: 6 ppm.
  3. (iii) Muscle: 2 ppm.
3. (3) Swine.
  1. (i) Kidney and fat: 12 ppm.
  2. (ii) Liver: 6 ppm.
  3. (iii) Muscle: 2 ppm.
(c) Related conditions of use. See §§ 520.2345c and 520.2345d of this chapter.