Will the Proposed Cattle Implant Labeling Changes Impact Feedlot Performance?

Will the Proposed Cattle Implant Labeling Changes Impact Feedlot Performance?

Implanting a feedlot animal
Photo credit Jessica Sperber.

This article is a follow-up to “Highlights of Feedlot Implant Labeling Changes Coming June 2023” published in the May 2023 UNL BeefWatch newsletter by Alfredo DiCostanzo.

The US Food and Drug Administration (FDA) has stated that beginning July 1, 2023, regulations surrounding growth-promoting implant products must have a label that specifies approval for reimplantation or repeated administration. This regulation will change the options that producers have when administering implants in the growing phase and feedlot phase of beef production.

What are my options for implanting feedlot cattle beginning July 1, 2023?  

First and foremost, it is important to select an implant strategy that will work for your operation by contacting your consulting professional or implant manufacturing company representatives. Producers are encouraged to document their implant strategy. There are three options to choose from when selecting an implant protocol for your feedyard that comply with FDA guidance: 1) Delayed administration of a single implant; 2) Long-acting or extended-release implant; 3) FDA-approved reimplant program.

Delayed administration of a single implant  

  • Cattle spending < 120 days on feed (DOF), there are a variety of implants to choose from and no changes to strategy need to be implemented
  • Cattle spending >120 DOF during feedlot phase, adjust implant administration date to target 100-120 days prior to harvest
    • Cattle not implanted upon arrival, administered implant later in growing/feeding period
  • Cattle type and size need to be taken into consideration
  • An implant with a higher dose of trenbolone acetate (TBA; 200 mg) is advised

Long-acting or extended-release implant

  • A long-acting implant generally offers up to 200-220 days of coverage
  • An extended-release implant has either a portion or all of the pellets covered in a polymer coating to extend performance
  • Removes the need to reimplant cattle
    • Reduces labor demands
    • Reduces animal handling stress

On-label reimplant program

There are currently a select number of implants on the market that have a reimplant or multiple implant administration claim on their label.

Benefits of reimplant programs:

  • Additional flexibility in marketing endpoint
    • Longer number of days of implant payout
    • Opportunity to administer vaccines, parasitic treatment, and sort cattle when processing during terminal implant

How will this change in implant regulations impact feeder cattle performance?

The performance differences between the implant strategies listed above range from 4 to 6 lbs of hot carcass weight (HCW) difference. Based on a weighted average from data collected by McLaughlin et al. (2013) in feedlot studies in Kansas, Colorado, Minnesota, and Texas, steers that were on a reimplant program had a 6 lb HCW advantage over steers that were administered a single extended-release implant. In a feedlot experiment conducted in Nebraska by Schumacher et al. (2019), heifers that were administered a reimplant program had a 6 lb HCW advantage over heifers that were administered a single long-acting implant. Similarly, a pooled summary by Smith et al. (2020) reported a 4 lb HCW advantage for a reimplant program over an extended-release implant in heifers.

The new implant labeling regulation will change the implant strategy options that producers have available. Based on previous data, the updated regulation may slightly impact performance, but the positive is that producers can still utilize growth-promoting implants to improve cattle performance.


McLaughlin, C. L., E. Larson, G. I. Crawford, R. S., Swingle, B. E. Depenbusch, B. Hunsaker, B. H. Vanimisetti, and F. L. Prouty. 2013. Comparison of reimplant program using Synovex Choice and Synovex Plus versus Revalor-XS in feedlot steers. Professional Anim. Sci. 29:219-227.

Schumacher, E., G. Erickson, R. Cooper, T. Scott, S. Bundy, G. Sides, and R. Cleale. 2019. A comparison of Synovex ONE alone to Synovex Choice followed by Synovex Plus as implant strategies for finishing heifers. Nebraska beef cattle report. Page 76-78.

Smith, Z. K., D. G. Renter, B. P. Holland, A. B. Word, G. I. Crawford, W. T. Nichols, B. L. Nuttelman, M. N. Streeter, L. J. Walter, J. P. Hutcheson, B. Dicke, R. T. Brandt, J. I. Szasz, T. C. Bryant, L. F. Pringle, Z. E. Carlson, G. E. Erickson, and B. J. Johnson. 2020. A pooled analysis of six large-pen feedlot studies: effects of a noncoated initial and terminal implant compared with a single initial and delayed-release implant on arrival in feedlot heifers. Transl. Anim. Sci. 4:1-12. doi 10.1093/tas/txaa109


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