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Head-to-head farm trials prove effectiveness of FACTREL® Injection (gonadorelin injection)

January 26, 2021
POSTED BY: Ken Learmont | DVM | Dairy Technical Services | Zoetis

Three on-farm studies of more than 12,000 cows showed FACTREL® Injection (gonadorelin injection), when used with LUTALYSE® Injection (dinoprost tromethamine injection), effectively helped synchronize estrous cycles and achieve equivalent conception risks as compared with other on-farm fixed-time artificial insemination (FTAI) protocols in lactating dairy cows.

One of those studies, a large FTAI noninferiority study involving 5,827 cows, showed:

  • FACTREL was not statistically different when used in FTAI protocols as compared with competitive GnRH products containing gonadorelin diacetate tetrahydrate.
  • First-service conception risk in cows treated with FACTREL was noninferior to farm protocols using competitive GnRH products.
  • No significant difference (p=0.65) in first-service conception risk between those treated with a 2-mL dose of FACTREL (37.6%) and those treated with farm protocols using competitive products (39%).1

In a second and independent study of 3,938 cows, the conception risk of animals treated with a 2-mL dose of FACTREL was not statistically different (p>0.10) than those treated with Cystorelin® (gonadorelin diacetate tetrahydrate) in an FTAI program.2

A third and independent study of 2,620 cows from 40 Canadian herds found no difference (p=0.84) in first-time conception risk between its two study groups. Furthermore, FACTREL was found to be noninferior to Fertiline® (gonadorelin acetate) in an FTAI protocol.3


Conception Risk (%) Reported in Recent Studies


Total Observations (n)

Conception Risk (%)


Other GnRH product


FTAI using FACTREL or current farm protocol1





FTAI using FACTREL or Cystorelin®2




> 0.10

FTAI using FACTREL or Fertiline®3




= 0.84


FACTREL is the only flexible-dose GnRH

With approved use of Zoetis products for FTAI, customers can use FACTREL and LUTALYSE® Injection (dinoprost tromethamine injection) or LUTALYSE® HighCon Injection (dinoprost tromethamine injection) with EAZI-BREED CIDR® Cattle Insert in many of the estrous synchronization protocols recommended by the Dairy Cattle Reproduction Council. The FDA approval of these products supports a convenient breeding schedule with the only flexible dose of a GnRH product and progesterone implant on the market, allowing producers to develop FTAI programs best suited for their operations, while taking the guesswork out of breeding.

Ken Mitchell, DVM, of Valley Veterinarians, based in Tulare, California, expressed confidence in FACTREL: “We were involved in a trial to test the efficacy of FACTREL used in a simple timed AI sequence. At the end of the trial, as a whole, our reproductive program on this dairy became noticeably more efficient during that period of time,” Mitchell said.

Committed to reproductive success

Raising the bar in dairy reproduction requires a team effort. Zoetis understands the changing needs of today’s dairy industry and is committed to providing flexible, comprehensive on-label solutions that are consistent with management practices.

Visit the Zoetis product pages to learn more about FACTRELLUTALYSE HighCon and EAZI-BREED CIDR as a complete and on-label synchronization program, or contact your veterinarian or Zoetis representative.


Avoid contact with skin by wearing protective gloves when handling EAZI-BREED CIDR inserts. Do not use in heifers of insufficient size or age for breeding or in cattle with abnormal, immature, or infected genital tracts. Do not use inserts more than once.

IMPORTANT SAFETY INFORMATION: FACTREL is for use in cattle only. See full Prescribing Information.

IMPORTANT SAFETY INFORMATION: Women of childbearing age and persons with respiratory problems should exercise extreme caution when handling LUTALYSE/LUTALYSE HighCon. LUTALYSE/LUTALYSE HighCon is readily absorbed through the skin and may cause abortion and/or bronchiospasms, therefore spillage on the skin should be washed off immediately with soap and water. Aseptic technique should be used to reduce the possibility of post-injection clostridial infections. Do not administer LUTALYSE/LUTALYSE HighCon in pregnant cattle unless cessation of pregnancy is desired. See full Prescribing Information for LUTALYSE. See full Prescribing Information for LUTALYSE HighCon.

1 Data on file, Study Report No. 13PETREPRO01-08D, Zoetis Inc.

2 Poock S, Lucy M. Conception rate for postpartum dairy cows treated with different gonadorelin (GnRH) products for first or resynchronized timed AI. Presented at: 2015 Midwest ADSA/ASAS Meeting; March 16-18, 2015; Des Moines, IA.

3 Caldwell V, Tison N, Martineau R, Dubuc J, Des Côteaux L. Non-inferiority randomized field clinical trial of two GnRH commercial products used in a systematic double-ovsynch protocol at first breeding in dairy cows, in Proceedings. Am Assoc Bov Pract Conf 2014.

All trademarks are the property of Zoetis Services LLC or a related company or a licensor unless otherwise noted. Cystorelin is a registered trademark of Boehringer Ingelheim Animal Health USA Inc. Fertiline is a registered trademark of Vetoquinol. CIDR is a registered trademark of InterAg.

© 2021 Zoetis Services LLC. All rights reserved. FAC-00036R1


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