Pregnancy detection in bighorn sheep (Ovis canadensis) using a fecal-based enzyme immunoassay.
We developed and validated an enzyme immunoassay for immunoreactive pregnanediol-3-glucuronide (iPdG) in feces to monitor reproductive status in desert and Rocky Mountain bighorn sheep (Ovis canadensis). Fecal iPdG concentrations were strongly correlated (r = 0.71) with serum progesterone concentrations in paired fecal and blood samples collected from 34 free-ranging desert bighorn sheep. In bimonthly fecal samples collected from 12 captive ewes, fecal iPdG profiles were similar between desert and Rocky Mountain bighorn sheep and we selected a pregnancy detection cutoff value of iPdG > or = 1.8 ng/mg feces. Fecal iPdG concentrations always exceeded this cutoff value when samples were collected from about day 60 of pregnancy to a few days before parturition, but values < 1.8 ng/mg (false negatives) were common for samples collected during the first 60 days of gestation. Although we tested a small number of known pregnant and non-pregnant ewes, the accuracy of the assay was 100% when two samples, collected 2 wk apart, were evaluated for any given ewe. Based on these data, this direct enzyme immunoassay for fecal progesterone metabolites has promise as a diagnostic tool to monitor hormone excretion and pregnancy in a free-ranging ungulate species.
Borjesson
D L
DL
Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis 95616, USA.
Boyce
W M
WM
Gardner
I A
IA
DeForge
J
J
Lasley
B
B
D000818:Animals; D000835:Animals, Wild / Q000502:physiology*; D005243:Feces / Q000737:chemistry*; D005260:Female; D007124:Immunoenzyme Techniques / Q000662:veterinary; D011247:Pregnancy; D011258:Pregnancy Tests / Q000379:methods / Q000662:veterinary*; D011276:Pregnanediol / Q000031:analogs & derivatives* / Q000032:analysis; D012756:Sheep / Q000502:physiology*
C022270:pregnanediol-3 alpha-glucuronide; D011276:Pregnanediol