North American bighorn sheep (Ovis canadensis) have experienced significant declines and population extirpations due to novel pathogens such as Mycoplasma ovipneumoniae. This disease continues to limit the population restoration of bighorn sheep. Therefore, understanding the demographic consequences of pathogen presence and the risk of contact between bighorn populations and potential...
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...
Published January 1896. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Unfished populations of cutthroat trout in three small coastal
streams in Oregon were studied from April of 1962 until November
of 1963. Population size, growth rate, and net production were
estimated for study areas in each stream. The nature of seasonal
movement patterns within the study areas and at fish...
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...
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...