BLM’s Fertility Vaccine May Control Wild Horse Population

WASHINGTON, DC – The Bureau of Land Management (BLM) has started testing a promising new fertility control vaccine that could help address the growing overpopulation of wild horses on public rangelands. Researchers believe the Oocyte Growth Factor (OGF) vaccine, administered to a captured wild mare through a single dose, may safely prevent pregnancy for up to three years or longer. The BLM seeks an effective one-dose version that, if proven viable, could help bolster existing methods used by the BLM to manage wild horse populations. The new fertility control trial comes as an annual report estimates approximately 95,000 wild horses and burros on public lands, the most ever estimated by the agency and far more than the 27,000 that roamed the land when the animals became federally protected and managed under the 1971 Wild Free-Roaming Horses and Burros Act. Without intervention, wild horse and burro herds will increase rapidly – doubling in less than five years. Constant overpopulation can stress critical ecosystems to the brink, causing severe damage to riparian and rangeland resources and also leads to the inhumane death of the horses and burros from thirst or starvation.