Life Sciences Commons^™

Twenty Years Of Spayvac® Research: Potential Implications For Regulating Feral Horse And Burro Populations In The United States, Ursula S. Bechert, Mark A. Fraker

Human–Wildlife Interactions

There are currently >75,000 feral horses (Equus ferus caballus) and burros (E. asinus ) on U.S. public lands, yet the Appropriate Management Level (AML) is set at just under 27,000. Wildlife managers, conservation biologists, and livestock ranchers are concerned about the impacts that these free-ranging horses have on shared rangelands. Immunocontraceptive vaccines may have the greatest potential to regulate horse population numbers once AML is reached; however, the vaccine must have multi-year efficacy to be both technically feasible and cost-effective. Immunocontraception based on porcine zona pellucida (PZP)-specific antigens is highly tissue-specific, targeting the ova, and blocking sperm binding through antibody …