Paul Beck, Oklahoma State University, Extension State Beef Cattle Nutrition Specialist
Over the last few weeks I have been describing the new rules from the FDA regarding reimplanting beef cattle. Last week I showed the implants labeled for use during the stocker and “Growing Calves in Drylot” phase of production.
The new FDA rules affect the use of implants in grower/starter yards and finishing operations the most. Look for new implant programs and approvals for products in the near future to address these rulings.
The FDA provided a list of currently approved and marketed implants available.
Here is the list:
Growing Beef Cattle Fed in Confinement for Slaughter
| Implant Name | Approved use | Approved for Reimplant in this class |
| Component TE-IS w/ Tylan‡ (trenbolone acetate and estradiol and tylosin tartrate implants) | For increased rate of weight gain and improved feed efficiency in growing beef steers fed in confinement for slaughter | No |
| Component TE-IH w/ Tylan‡ (trenbolone acetate and estradiol and tylosin tartrate implants) | For increased rate of weight gain in growing beef heifers fed in confinement for slaughter | No |
| Component TE-200 w/ Tylan‡ (trenbolone acetate and estradiol and tylosin tartrate implants) | For increased rate of weight gain and improved feed efficiency in growing beef steers and heifers fed in confinement for slaughter | No |
| Compudose (estradiol extended-release implants) | 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 | No |
| Encore (estradiol extended-release implants) | 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 |
| Ralgro (zeranol implants) | For increased rate of weight gain and improved feed efficiency in growing beef steers and heifers fed in confinement for slaughter | No |
| Revalor-IS (trenbolone acetate and estradiol implants) | For increased rate of weight gain and improved feed efficiency in growing beef steers fed in confinement for slaughter | No |
| Revalor-S (trenbolone acetate and estradiol implants) | For increased rate of weight gain and improved feed efficiency in growing beef steers fed in confinement for slaughter | No |
| Revalor-XS (trenbolone acetate and estradiol extended-release implants) | For increased rate of weight gain and improved feed efficiency for up to 200 days after implantation in growing beef steers fed in confinement for slaughter | No |
| Revalor-IH (trenbolone acetate and estradiol implants) | For increased rate of weight gain in growing beef heifers fed in confinement for slaughter | No |
| Revalor-H (trenbolone acetate and estradiol implants) | For increased rate of weight gain and improved feed efficiency in growing beef heifers fed in confinement for slaughter | No |
| Revalor-XH (trenbolone acetate and estradiol extended-release implants) | For increased rate of weight gain and improved feed efficiency for up to 200 days after implantation in growing beef heifers fed in confinement for slaughter | No |
| Revalor-200 (trenbolone acetate and estradiol implants) | For increased rate of weight gain and improved feed efficiency in growing beef steers and heifers fed in confinement for slaughter | No |
| Synovex C (progesterone and estradiol benzoate implants) | Synovex C is only approved for use in growing beef steers fed in confinement for slaughter when it is used as part of a reimplantation program with Synovex S (see next column). | Yes Synovex C is approved for increased rate of weight gain in growing beef steers fed in confinement for slaughter in a reimplantation program where Synovex C is the first implant and a Synovex S implant is administered approximately 70 days later. |
| Synovex S (progesterone and estradiol benzoate implants) | For increased rate of weight gain and improved feed efficiency in growing beef steers fed in confinement for slaughter | Yes Synovex S is also approved for increased rate of weight gain in growing beef steers fed in confinement for slaughter in a reimplantation program where Synovex C or Synovex S is the first implant and a Synovex S implant is administered approximately 70 days later. |
| Synovex H (testosterone propionate and estradiol benzoate implants) | For increased rate of weight gain and improved feed efficiency in growing beef heifers fed in confinement for slaughter | No |
| Synovex One Grower (trenbolone acetate and estradiol benzoate extended-release implants) | For increased rate of weight gain for up to 200 days in growing beef steers and heifers fed in confinement for slaughter | No |
| Synovex Choice (trenbolone acetate and estradiol benzoate implants) | For increased rate of weight gain in growing beef steers fed in confinement for slaughter and for increased rate of weight gain and improved feed efficiency in growing beef heifers fed in confinement for slaughter | Yes Synovex Choice is also approved for increased rate of weight gain for up to 200 days in growing beef steers and heifers fed in confinement for slaughter in a reimplantation program where Synovex Choice is the first implant and a Synovex Choice, Synovex Plus, or Synovex ONE Feedlot implant is administered 60 to 120 days later. |
| Synovex Plus (trenbolone acetate and estradiol benzoate implants) | For increased rate of weight gain and improved feed efficiency in growing beef steers fed in confinement for slaughter and for increased rate of weight gain in growing beef heifers fed in confinement for slaughter | Yes Synovex Plus is also approved for increased rate of weight gain for up to 200 days in growing beef steers and heifers fed in confinement for slaughter in a reimplantation program where Synovex Choice is the first implant and a Synovex Plus implant is administered 60 to 120 days later. |
| Synovex One Feedlot (trenbolone acetate and estradiol benzoate extended-release implants) | 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 | Yes Synovex One Feedlot is also approved for increased rate of weight gain for up to 200 days in growing beef steers and heifers fed in confinement for slaughter in a reimplantation program where Synovex Choice is the first implant and a Synovex One Feedlot implant is administered 60 to 120 days later. |
My take home messages from this list:
1) Ralgro is approved for the preweaning “Beef Calves”; “Growing Beef Cattle on Pasture” and “Growing Beef Cattle Fed in Confinement for Slaughter” stages as well, but has no reimplant label claims.
2) Synovex-S and Synovex-H are only approved for “Growing Beef Cattle Fed in Confinement for Slaughter”.
3) Until the finishing phase of production both Compudose and Encore are only approved in steers.
4) All Component brand implants containing Tylan (Elanco Animal Health products) will now have to be approved and scripted by a veterinarian due to the VMD ruling.
5) The only implants labeled for reimplanting during finishing are Synovex brand implants and these reimplant labels are very specific regarding products and timing of reimplanting cattle.
Here are some resources available for further information: https://www.fda.gov/animal-veterinary/resources-you/fda-letter-industry-provides-additional-information-and-clarification-use-beef-cattle-ear-implants#1