Section 520.90c - Ampicillin boluses(a)Specifications. Each bolus contains ampicillin trihydrate equivalent to 400 milligrams of ampicillin.(b)Sponsor. See No. 054771 in § 510.600(c) of this chapter.(c)Related tolerances. See § 556.40 of this chapter.(d)Conditions of use in nonruminating calves -(1)Amount. 5 milligrams per pound of body weight twice daily not to exceed 4 days.(2)Indications for use. Oral treatment of bacterial enteritis (colibacillosis) caused by E. coli.(3)Limitations. Treated calves must not be slaughtered for food during treatment and for 7 days after the last treatment. Federal law restricts this drug to use by or on the order of a licensed veterinarian.57 FR 37322, Aug. 18, 1992, as amended at 58 FR 61016, Nov. 19, 1993; 60 FR 55659, Nov. 2, 1995; 79 FR 28818 , May 20, 2014. Redesignated and amended at 85 FR 18118 , Apr. 1, 2020