Embryonic loss in mares: Nature of loss after experimental induction by ovariectomy or prostaglandin F(2alpha).
Abstract: Twenty-one pregnant pony mares were assigned to one of the following groups: 1) controls, 2) ovariectomy at Day 12, 3) ovariectomy at Day 12 plus daily progesterone treatment on Days 12 to 40, 4) PGF(2alpha) on Day 12, 5) PGF(2alpha) on Day 21, and 6) PGF(2alpha) on Day 30. Based on daily examinations by ultrasound, the embryonic vesicle was maintained to Day 40 in all control mares and in mares that were ovariectomized on Day 12 and given progesterone. The embryonic vesicle was lost in all mares of the other four groups. Administration of progesterone prevented the embryonic loss associated with ovariectomy at Day 12, indicating that progesterone may be the only ovarian substance required for survival of the early embryo. The mean number of days to embryonic loss was greater for mares treated with PGF(2alpha) on Day 12 (6.8 days) than for mares ovariectomized on Day 12 (3.0 days). In the PGF(2alpha)-treated group, the vesicles did not become fixed at the expected time (Day 15), and mobility continued until the day of loss. In the mares treated with PGF(2alpha) on Day 21 and in one of the mares treated on Day 30, the vesicle was lost within one to three days without prior indication. Loss may have occurred by expulsion through the cervix, since the cervix was patent on the day of loss in these mares and in the mares ovariectomized or treated with PGF(2alpha) on Day 12. In the remaining mares treated on Day 30, the intact embryonic vesicle was dislodged on Day 31 or 32. The dislodged vesicle was mobile within the uterus and was frequently found in the uterine body. The fluid volume of the dislodged vesicle gradually decreased, and the fluid was no longer detected by Day 38 to 42. Some of the placental fluids may have been eliminated by resorption since the cervix remained closed while the fluid volume decreased.
Publication Date: 1985-07-01 PubMed ID: 16726061DOI: 10.1016/0093-691x(85)90214-6Google Scholar: Lookup
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- Journal Article
Summary
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The research examines the causes of embryonic loss in mares, particularly how procedures such as ovariectomy and prostaglandin F(2alpha) treatment affect embryonic development and survival. Findings reveal that progesterone can prevent embryonic loss post-ovariectomy, indicating its potential as a crucial substance required for early embryo survival.
Design and Methodology
- The research involved 21 pregnant pony mares that were divided into six groups. These groups received different treatments: no treatment, ovariectomy on Day 12, ovariectomy on Day 12 with daily progesterone treatment from Days 12 to 40, PGF(2alpha) on Day 12, on Day 21, and on Day 30.
- The embryonic vesicle condition was tracked daily using ultrasound. Its survival or loss was the key metric of the study.
Key Findings
- The embryonic vesicle was sustained until Day 40 in control mares and mares that underwent ovariectomy on Day 12 but received progesterone treatment. The embryonic vesicle was lost in all mares from the other groups.
- Administering progesterone post-ovariectomy on Day 12 prevented embryonic loss, suggesting progesterone may be the sole ovarian substance required for the early embryo’s survival.
- Mares treated with PGF(2alpha) on Day 12 experienced delayed embryonic loss compared to mares ovariectomised on Day 12 (6.8 days vs 3.0 days).
Additional Observations
- In the PGF(2alpha)-treated group, the embryonic vesicles did not become fixed at the expected time (Day 15) and remained mobile until loss.
- The vesicle was lost within one to three days in mares treated with PGF(2alpha) on Day 21 and one mare treated on Day 30, without prior signs. This loss might be due to expulsion through the cervix.
- In some of the remaining mares treated on Day 30, the intact embryonic vesicle was dislodged on Day 31 or 32, usually found mobile within the uterine body.
- The fluid in these dislodged vesicles gradually declined and was undetectable by Day 38 to 42. The study surmises some placental fluids might have been absorbed as the cervix stayed closed while fluid volumes decreased.
Cite This Article
APA
Ginther OJ.
(1985).
Embryonic loss in mares: Nature of loss after experimental induction by ovariectomy or prostaglandin F(2alpha).
Theriogenology, 24(1), 87-98.
https://doi.org/10.1016/0093-691x(85)90214-6 Publication
Researcher Affiliations
- Department of Veterinary Science University of Wisconsin Madison, WI 53706 USA.
Citations
This article has been cited 1 times.- Segabinazzi LGTM, Roberts BN, Peterson EW, Ambrosia R, Bergfelt D, Samper J, French H, Gilbert RO. Early Pregnancy in Jennies in the Caribbean: Corpus Luteum Development and Progesterone Production, Uterine and Embryo Dynamics, Conceptus Growth and Maturation. Animals (Basel) 2022 Jan 6;12(2).
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