Date of Graduation
Davis College of Agriculture, Natural Resources and Design
Animal and Nutritional Sciences
E. Keith Inskeep.
Experiments were performed to determine if a short-lived corpus luteum was embryotoxic in ewes given supplemental progesterone and the route of transfer of embryotoxic products. Mated ewes were lutectomized or sham lutectomized on day 4 after estrus. Following surgery, ewes received saline or PGF 2alpha through days 6 or 7. Pregnancy rate was reduced after treatment with PGF2alpha (P < 0.001) compared to controls and was increased in PGF2alpha-treated ewes by lutectomy (P < 0.05). Mated ewes with bilateral ovulations were unilaterally lutectomized, and each uterine horn was ligated to eliminate intercornual flow on day 4 after estrus. Treatment with PGF2alpha on day 5 through 8 reduced pregnancy rates (P < 0.01), but embryonic survival did not differ in the uterine horns ipsilateral or contralateral to the regressing CL. The regressing CL is embryotoxic in progesterone-supplemented ewes, and embryotoxic luteal products have been shown to act by non-local pathways.
Costine, Beth Alyson, "Evidence for a systemic embryotoxic effect of early luteal regression in the ewe" (2000). Graduate Theses, Dissertations, and Problem Reports. 1124.