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

One of those studies, the dairy industry’s largest fixed-time AI non-inferiority study to date involving 5,827 cows, showed FACTREL was not statistically different when used in fixed-time AI protocols as compared to competitive GnRH products containing gonadorelin diacetate tetrahydrate. The first-service conception risk in cows treated with FACTREL was noninferior to farm protocols using competitive GnRH products. In addition, there was 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) to those treated with Cystorelin® (gonadorelin diacetate tetrahydrate) in a fixed-time AI 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 a fixed-time AI protocol.3

Conception Risk (%) Reported in Recently Published Studies


Total Observations (n)

Conception Risk (%)


Other GnRH product


FTAI using FACTREL or current farm protocol1




= 0.65

FTAI using FACTREL or Cystorelin® 2




> 0.10

FTAI using FACTREL or Fertiline® 3




= 0.84


“Using FACTREL and LUTALYSE in combination provides an effective, U.S. Food and Drug Administration (FDA)-approved method of synchronizing estrus using a variety of fixed-time AI programs,” said Ken Learmont, DVM, senior veterinarian, Dairy Technical Services, Zoetis. “With more than 12,000 combined cows studied, producers can have the peace of mind that FACTREL is a safe and efficacious product when used according to its label.”

FACTREL now offered in a larger, more convenient vial size

Zoetis continues to focus on convenience for producers by now offering FACTREL in a 50-mL vial size. The larger bottle size delivers ease by allowing producers to treat up to 25 cows per bottle, which is more than most other GnRH products on the market.

With approved use of Zoetis products for fixed-time AI, customers can use LUTALYSE and FACTREL in many of the synchronization protocols recommended by the Dairy Cattle Reproduction Council. The FDA approval of FACTREL and LUTALYSE includes a flexible schedule and the only flexible dose of a GnRH product, allowing producers to develop protocols that fit their dairy’s needs.

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.”

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.

“This new offering is a continuation of Zoetis’ commitment to providing the industry with comprehensive reproductive management solutions,” Dr. Learmont said. “We’ll continue to invest in new, practical and on-label solutions and research that will help improve reproduction so veterinarians and producers can use them with confidence. This provides producers the peace of mind they are doing the right thing for their dairy.”

For more than 30 years, as the leader in dairy reproduction research, support and technical services, Zoetis has been delivering innovations to help producers and veterinarians improve reproductive programs.

To learn more about FACTREL and LUTALYSE as an on-label synchronization program, visit or contact your veterinarian or Zoetis representative.

IMPORTANT SAFETY INFORMATION FOR FACTREL: FACTREL Injection is for use in cattle only. Please see full Prescribing Information.

IMPORTANT SAFETY INFORMATION FOR LUTALYSE: Women of childbearing age and persons with respiratory problems should exercise extreme caution when handling LUTALYSE. LUTALYSE 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 in pregnant cattle unless cessation of pregnancy is desired. See full Prescribing Information.