§ 522.840 - Estradiol.

§ 522.840 Estradiol.

(a) Specifications. Each silicone rubber implant contains 25.7 or 43.9 milligrams (mg) estradiol and is coated with not less than 0.5 mg oxytetracycline powder.

(b) Sponsor. See No. 058198 in § 510.600(c) of this chapter.

(c) Related tolerances. See § 556.240 of this chapter.

(d) Conditions of use. For implantation in steers and heifers as follows:

(1) Amount. Insert one Amounts and indications for use -

(i) 25.7-mg

implant every 200 days; insert one

extended-release implant. Insert one implant for increased rate of weight gain for up to 200 days in beef steer calves 2 months of age and older; for increased rate of weight gain for up to 200 days in growing beef steers and heifers on pasture (stocker, feeder, and slaughter); and for increased rate of weight gain and improved feed efficiency for up to 200 days in growing beef steers and heifers fed in confinement for slaughter.

(ii) 43.9-mg

implant every 400 days.

(2) Indications for use. For

extended-release implant. Insert one implant for increased rate of weight gain for up to 400 days in beef steer calves 2 months of age and older; for increased rate of weight gain

in suckling and pastured growing steers; for improved feed efficiency and

for up to 400 days in growing beef steers and heifers on pasture (stocker, feeder, and slaughter); and for increased rate of weight gain and improved feed efficiency for up to 400 days in growing beef steers and heifers fed in confinement for slaughter.

No additional effectiveness may be expected from reimplanting in less than 200 days for the 25.7-mg implant or 400 days for the 43.9-mg implant. (3

(2) Limitations. For subcutaneous ear implantation

in steers and heifers only

only. Not approved for repeated implantation (reimplantation) with this or any other cattle ear implant within each separate production phase (beef steer calves 2 months of age and older, growing beef steers on pasture (stocker, feeder, and slaughter), growing beef steers and heifers fed in confinement for slaughter). Safety and effectiveness following reimplantation have not been

established in

evaluated. Do not use in beef calves less than 2 months of age, dairy calves, and veal calves. A withdrawal period has not been established for this product in

preruminating

pre-ruminating calves. Do not use in dairy cows or in animals intended for subsequent breeding. Use in these cattle may cause drug residues in milk and/or in calves

to be processed for veal

born to these cows.

[69 FR 67818, Nov. 22, 2004, as amended at 77 FR 31723, May 30, 2012; 81 FR 48702, July 26, 2016; 87 FR 10969, Feb. 28, 2022; 88 FR 14898, Mar. 10, 2023]