Whole blood selenium levels were measured in 207 horses, representing 41 ranches and 11 regions throughout Oregon. Age, sex,
diet, and history of disease were recorded. Diet was divided into
three categories; local feed only, commercial feed, and Se supplemented feed. Region (p<.01), diet type (p<.01), and a region x...
Intact and ovariectomized (OVX) pony mares were randomly assigned to treatments of morphine (M), naloxone (N), or a saline control (C) to determine if endogenous opioid peptides (EOP) play a role in equine seasonal breeding. Morphine was expected to decrease luteinizing hormone (LH), whereas N (an opiate antagonist) should in...
Studies were conducted in order to evaluate the efficacy of the
orally active, synthetic progestagen, altrenogest, for assisting in the
establishment and maintenance of pregnancy in mares. In experiment
I, nine pony mares were bred, and started on altrenogest treatment
on Day 4 after ovulation. On Day 10 after ovulation,...
Urinary steroids have been studied during early and late pregnancy in
domestic horses or sporadic samples at various stages of pregnancy in wild
equidae. In our studies, urinary estrone sulfate (E1S) and pregnanediol
glucuronide (PdG) were monitored throughout pregnancy in six pony mares by
enzyme immunoassay (EIA). Both hormones were...
Previous work in this laboratory revealed that hormone analysis using fecal samples may predict the number of fetuses carried by pregnant ewes at mid- to late gestation. Reliable lambing number prediction is useful to the producer. Using gas chromatography/mass spectrometry the 5α- and 5β-series of pregnanes and selected 4- and...
Aims of this research were to find the time period and specific progestins
reflective of the transition from ovarian source to placental source during early gestation
in mares. An attempt was made to describe an accurate profile of total and individual
progestins in plasma and feces from 64 to 150...
Mares have an atypical hormone profile during pregnancy. Systemic progesterone (P4) levels approach zero by day 220 of gestation. Other reduced pregnanes such as 5α-pregnane-3, 20-dione (5α), 5α-pregnane-3β, 20α-diol (βα), 3β-hydroxy-5α-pregnan-3-one (3β) and 20α-hydroxy-5α-prenan-3-one (20α), increase to near μg/mL levels in the peripheral system of the mare until directly before...