Immunocontraception in wild horses: One inoculation provides two years of infertility

John W. Turner, Irwin Liu, Douglas R. Flanagan, Allen T. Rutberg, Jay F. Kirkpatrick

Research output: Contribution to journalArticle

37 Citations (Scopus)

Abstract

Previous studies reported one year of contraception associated with a 1-injection porcine zona pellucida (PZP) vaccine. We have subsequently determined contraceptive effectiveness of a presumptive 1-injection, 2-year-duration PZP vaccine in free-roaming wild horses (Equus caballus) in Nevada, USA. In January 2000, we captured, freeze-branded, treated, and subsequently released 96 adult females that received 1) a primary dose of vaccine emulsion consisting of aqueous PZP and Freund's Complete Adjuvant, and 2) booster doses of PZP and adjuvant in controlled-release polymer pellets. We determined PZP release characteristics of pellets in vitro, prior to field use. We determined reproductive success in treated and untreated females through October 2004 via measurement of estrone sulfate and progesterone metabolites in fresh feces collected from the ground and by twice-annual foal counts. Among treated females, annual reproductive success from 2001 though 2004 sequentially was 5.9%, 14.0%, 32.0%, and 47.5%. Untreated females showed average reproductive success of 53.8 ± 1.3% across this period. This study revealed that: 1) PZP acted as an effective contraceptive for 2 years posttreatment; 2) some residual contraceptive effect remained in year 3; and 3) fertility returned to control levels by year 4 posttreatment. It appears that controlled-release technology can replace both the second (1-month) and annual booster injection of PZP vaccine, thereby decreasing cost and increasing efficiency of use of this vaccine in wild horse management.

Original languageEnglish (US)
Pages (from-to)662-667
Number of pages6
JournalJournal of Wildlife Management
Volume71
Issue number2
DOIs
StatePublished - Apr 1 2007
Externally publishedYes

Fingerprint

immunocontraception
infertility
zona pellucida
vaccine
horse
inoculation
vaccination
horses
swine
reproductive success
vaccines
contraceptives
injection
adjuvants
pellets
antifertility effect
emulsion
feces
contraception
estrone

Keywords

  • Adjuvant
  • Controlled-release vaccine contraception
  • Equus caballus
  • Field study
  • Free-roaming wild horse
  • Pregnancy testing
  • Zona pellucida antigen

ASJC Scopus subject areas

  • Nature and Landscape Conservation
  • Ecology
  • Ecology, Evolution, Behavior and Systematics

Cite this

Immunocontraception in wild horses : One inoculation provides two years of infertility. / Turner, John W.; Liu, Irwin; Flanagan, Douglas R.; Rutberg, Allen T.; Kirkpatrick, Jay F.

In: Journal of Wildlife Management, Vol. 71, No. 2, 01.04.2007, p. 662-667.

Research output: Contribution to journalArticle

Turner, John W. ; Liu, Irwin ; Flanagan, Douglas R. ; Rutberg, Allen T. ; Kirkpatrick, Jay F. / Immunocontraception in wild horses : One inoculation provides two years of infertility. In: Journal of Wildlife Management. 2007 ; Vol. 71, No. 2. pp. 662-667.
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