Alfalfa accumulates phytoestrogens and when ingested binds the estrogen receptor and induces morphological changes similar to endogenous estrogens. The objective of this study is to evaluate morphological changes in uteri, vulva, and teats of ovariectomized prepubertal ewe lambs. Eighteen prepubertal ewe lambs were ovariectomized in November 2000 and fed nonestrogenic...
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...
A series of trials was conducted with Polypay (P), Coopworth
(CP), Hampshire (H), and crossbred ewes over a two year period at three
locations to assess the effects of ewe body condition and pre-lambing
supplementation on ewe productivity. Supplementation trials were
conducted at all three locations in Year 1 using...
Two experiments were conducted to examine the effect of
a cyclopropenoid fatty acid on luteal cell function. In Exp.
1, 12 mature ewes were mated to a fertile ram, assigned to two
groups (n = 6/group) and laparotomized on day 18 of gestation.
Ewes with corpora lutea (CL) in both...
Two experiments were conducted to determine whether in
ewes uterine concentrations of estrogen and progesterone
receptors are affected by the presence of a conceptus or by
the hormonal milieu associated with extremes in photoperiod
to which ewes are exposed.
In Exp.1, nine mature ewes were unilaterally
ovariectomized by removing an...
Two trials were conducted over consecutive years to examine the effects of ewe
body condition and post-mating nutrition on ovulation rates and embryo survival. Trial 1
used 146 Polypay ewes ranging in age from 5 to 8 years in a 3 x 2 factorial array of pre-mating
(high-H, low flushed-LF...
One thousand twenty-three lambing records of 351 ewes bred in a
rotational crossbreeding system involving Columbia or Targhee,
Hampshire and Finnish Landrace breeds were examined. A regression
approach was used to determine the effects of breeds and heterosis on
wool grade, greasy fleece weight, ewe weight at lambing, lambing date,...