Effects of two porcine zona pellucida immunocontraceptive vaccines on ovarian activity in horses
Bibliographic record
Abstract
ABSTRACT Feral horse population growth rates as high as 25% are of concern to those responsible for managing range lands as well as conservation groups. Current methods to control these populations include adoption and long‐term holding, which are both costly and controversial. Porcine zona pellucida (pZP) immunocontraception may have the greatest potential to control fertility because it has proven to be effective in other studies and vaccines are easy and safe to administer. One pZP vaccine formulation, SpayVac® (ImmunoVaccine Technologies, Inc., Halifax, NS, Canada), has demonstrated single‐dose, multi‐year contraceptive efficacy in other wildlife species, which would make it both practical and economical for field application. Over a 7‐month period during the breeding season, we assessed the effect on ovarian activity of 2 formulations of SpayVac, 1 non‐aqueous with modified Freund's adjuvant (MFA) and the other, an aqueous emulsion with MFA, compared to controls ( n = 7 per group). Comparative reproductive parameters included serum concentrations of progesterone (P 4 ) determined by enzyme‐linked immunosorbent assay (ELISA), ovarian activity assessed by transrectal ultrasound and palpation, as well as gross and histological examination of ovaries upon necropsy ( n = 9 or 3 mares from each group) or after ovariectomy ( n = 12 or 4 mares from each group). We determined serum antibody titers using ELISA. Mean serum concentrations of P 4 were less in the non‐aqueous MFA treatment group compared to control mares ( P < 0.025). Ovaries collected from control mares weighed more ( P = 0.002) and had greater variation ( P = 0.003) than those from either vaccinated group. Both treatment groups also had smaller ovaries and fewer follicles compared to controls ( P < 0.001). Three to 4 months after vaccination, 93% of SpayVac‐injected mares ceased cycling; whereas all control mares continued to cycle throughout the study. Relatively constant antibody titers were reached by week 6 post‐vaccination, although we found appreciable variation within treatment groups, especially 4–8 weeks post‐vaccination. Based on our study, the SpayVac formulations impair ovarian function but do not affect other major organ systems, and could provide a safe and effective immunocontraceptive option for mares. Additional research to elucidate the vaccine's mechanism of action, actual contraceptive efficacy, and long‐term effects are still needed. © 2013 The Wildlife Society.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".