In May, the U.S. Food and Drug Administration (FDA) announced the approval of GONAbreed (gonadorelin acetate). This week, Daniel G. McChesney, PhD, director of the Office of Surveillance and Compliance at FDA’s Center for Veterinary Medicine issued a letter announcing the approval of a second gonadorelin (GnRH) product, FACTREL Injection (gonadorelin hydrochloride) from Zoetis Inc., for estrous synchronization in lactating dairy cows.
Six GnRH products are FDA-approved to treat cystic ovaries in dairy cows. Of these six products, only FACTREL and GONAbreed are also FDA-approved for use in combination with another drug for synchronizing estrous cycles in lactating dairy cows.
FACTREL is approved for use in combination with LUTALYSE (dinoprost tromethamine). GONAbreed is approved for use in combination with Cloprostenol sodium. Other than these combinations, it is illegal to use GnRH products in combination with another drug for estrous synchrony.
By prescribing FDA-approved FACTREL, McChesney says, you’re choosing one of the only two marketed GnRH products shown to be safe and effective for use in combination with another drug for synchronizing estrous cycles in lactating dairy cows. Used together in a breeding program, FACTREL and LUTALYSE synchronize estrous cycles to allow fixed-time artificial insemination in lactating dairy cows.
The letter, including technical information on FACTREL, is available online from FDA.