White-tailed deer (Odocoileus virginianus) populations in the United States have increased in recent years, particularly in urban and suburban landscapes where traditional measures of population control are difficult to implement. As a result of rapid urban development in the last several years, the Lyndon B. Johnson Space Center (JSC) located southeast of the Houston, Texas metroplex has become a refuge for an increasing, isolated urban white-tailed deer population. The use of the immunocontraceptive SpayVac™ has been proposed as a feasible measure in controlling the JSC deer population; however, the potential effects of the vaccine on deer movements are unknown. Furthermore, there is a need to estimate deer densities when using intensive management practices (e.g., contraceptive program) which requires an assessment of methods to estimate urban deer densities. The objectives of my study were to (1) compare female movements and ranges between deer treated with SpayVac™ versus non-treated (control) deer, (2) determine if the timing of SpayVac™ treatment affected efficacy, and (3) compare mark-resight and distance sampling methodologies in estimating urban deer densities. I captured and radio-marked 59 adult female deer at JSC. I found annual ranges between treated (mean 95% kernel = 82 ha, mean 50% kernel = 11 ha) and control (mean 95% kernel = 77 ha, mean 50% kernel = 11 ha) deer were similar (P > 0.05). Furthermore, I found daily movements between treated (mean = 430 m) and control (mean = 403 m) deer also were similar (P > 0.05). The use of SpayVac™ did not alter movements and ranges of treated deer, and is unlikely to increase deer-vehicle collisions due to increased movements. I found the timing efficacy (i.e., time needed for vaccine to prevent pregnancy) of SpayVac™ was 0% for does treated closer to the breeding season than previously believed. For JSC, this expands the application time for SpayVac™ treatment to a 5-6 month window rather than the 2-3 month window as previously recommended. I found mark-resight estimates (160-174 deer) were congruent with minimum known alive estimates at JSC (158), whereas distance sampling estimates (83-114) were biased low. The use of non-random road counts likely resulted in the low estimates using distance sampling. I recommend that future efforts to monitor population densities at JSC use mark-resight estimates along with the on-going contraceptive program.

The Bureau of Land Management (BLM) maintains a growing number of feral horses on public rangelands. With population growth rates as high as 22% annually, herds are exceeding their carrying capacity and millions of dollars are spent maintaining captured horses in holding facilities awaiting adoption. To manage the feral horse population, the BLM is seeking a contraceptive that is safe, can be remotely delivered, requires only a single administration and is effective for several years. Contraceptive strategies have been developed for feral horses that include hormone implants, chemical intrauterine devices, and immunocontraception. Porcine zona pellucida (pZP) immunocontraceptive vaccines have shown great potential for providing safe, long-term contraception in feral horses. ImmunoVaccine Technologies (Halifax, Nova Scotia, Canada) has developed a liposome encapsulated pZP formulation known as SpayVac™ (SpayVac), which after a single-dose provides multi-year contraceptive efficacy. In a continued effort to optimize the acceptability and efficacy of SpayVac, ImmunoVaccine Technologies developed alternative adjuvant preparations using either killed Mycobacterium butyricum (Modified Freund's Adjuvant; MFA) or a proprietary non-Mycobacterium based adjuvant (IVT) that are proposed to have less of the undesirable side-effects associated with Mycobacterium tuberculosis. Therefore, the objective of this research was to evaluate SpayVac in different adjuvant formulations for efficacy of contraception as measured by pZP titers and estrous cyclicity in treated mares. Domestic mares (n=28) were randomly assigned to four treatments (7 mares per treatment): adjuvant alone or saline (Control) or SpayVac vaccines in one of three adjuvant preparations: IVT or MFA in either an aqueous (MFA aq) or non-aqueous (MFA non-aq) suspension. Pre-immune blood samples were collected from each mare and mares were injected in the neck with a single injection of the Control or SpayVac. Subsequent blood samples were collected at weekly intervals for 26 weeks. Sera were analyzed for pZP titers and progesterone using ELISA. At the conclusion of the study, ovaries were recovered by ovariectomy (16 mares) or at necropsy (12 mares) for histologic analysis and collection of morphometric data and oocytes. Titers for pZP were greater (P<0.05) in IVT and MFA mares compared to Control mares and for MFA compared to IVT mares. Mares vaccinated with MFA aq had greater (P<0.05) pZP titers at 2 weeks post-injection compared to mares injected with IVT or MFA non-aq and at 3 weeks post-injection compared to mares injected with IVT. MFA non-aq mares had greater (P<0.05) pZP titers at 6 weeks post-injection compared to IVT mares and, although not significantly different, titers in MFA non-aq mares remained greater during weeks 8, 10, 14, 18 and 22 compared to IVT and MFA aq mares. Mean serum progesterone concentrations were greater (P<0.05) in Control compared to MFA non-aq mares. Mean ovarian weights, oocyte diameters, zona pellucida thicknesses and the number of horse sperm bound to oocytes recovered from vaccinated mares were greater (P<0.05) in Control mares compared to IVT and MFA mares. As judged by pZP titers and serum progesterone, these results suggest that SpayVac suspended in the MFA non-aqueous formulation exerted the greatest contraceptive effects in treated mares. This preparation of SpayVac may meet the criteria cited by the BLM for their most desirable immunocontraceptive. / Graduation date: 2012