Two uses of the synthetic progestagen altrenogest for aiding in the establishment and maintenance of pregnancy in mares Public Deposited

http://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/d217qs36c

Descriptions

Attribute NameValues
Creator
Abstract or Summary
  • 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, these mares were given an intramuscular injection of prostaglandin F₂∞ (PGF, 3 mg) in order to regress their corpora lutea (endogenous progesterone source). Frequent rectal palpation of reproductive tracts indicated that seven of the nine mares were pregnant at Day 35. Four of these mares maintained pregnancy through Day 85 of gestation, at which time the pregnancies were terminated. Plasma progesterone levels were monitored indicating that the primary corpora lutea regressed following the Day 10 PGF and that secondary corpora lutea formed in the pregnant mares between Days 32 and 85. The pregnancies continued even after PGF injections on Days 65 and 75 of gestation. Altrenogest treatment appears to maintain pregnancy in the absence of a functional primary corpus luteum during early gestation. In experiment II, the effect of altrenogest treatment on pregnancy maintenance rates in unsynchronized embryo transfer recipient mares was evaluated. Day 7 non-surgical embryo recovery rate was 57% (38/67). Non-surgical transfer of these embryos into altrenogest-treated recipient mares that ovulated between 3 days before and 3 days after the donor resulted in a 77% (10/13) 30-day pregnancy rate. Transfer of embryos into altrenogest-treated recipients that ovulated between 4 days before and 6 days after the donor yielded an overall pregnancy rate of 64% (16/25) at day 30 of gestation. No recipients that were in estrus at the start of treatment, nor recipients that ovulated 5 or more days before the donor, maintained pregnancy. Plasma progesterone profiles indicate that altrenogest treatment appears to have no effect on luteal function during early pregnancy in mares. Treatment of embryo recipient mares with altrenogest appears to allow for extension of the degree of donor-recipient ovulation synchrony required for successful non-surgical embryo transfer. Altrenogest treatment also seems to aid in pregnancy maintenance in recipients experiencing luteal dysfunction.
Resource Type
Date Available
Date Copyright
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Academic Affiliation
Non-Academic Affiliation
Subject
Rights Statement
Peer Reviewed
Language
Digitization Specifications
  • File scanned at 300 ppi (Monochrome) using ScandAll PRO 1.8.1 on a Fi-6670 in PDF format. CVista PdfCompressor 4.0 was used for pdf compression and textual OCR.
Replaces
Additional Information
  • description.provenance : Approved for entry into archive by Patricia Black(patricia.black@oregonstate.edu) on 2013-06-27T17:05:14Z (GMT) No. of bitstreams: 1 WeeksLindaC1987.pdf: 220299 bytes, checksum: fc818c7de71d75a816432c9074f7e865 (MD5)
  • description.provenance : Approved for entry into archive by Deborah Campbell(deborah.campbell@oregonstate.edu) on 2013-07-17T18:17:59Z (GMT) No. of bitstreams: 1 WeeksLindaC1987.pdf: 220299 bytes, checksum: fc818c7de71d75a816432c9074f7e865 (MD5)
  • description.provenance : Submitted by Katy Davis (kdscannerosu@gmail.com) on 2013-06-26T21:25:57Z No. of bitstreams: 1 WeeksLindaC1987.pdf: 220299 bytes, checksum: fc818c7de71d75a816432c9074f7e865 (MD5)
  • description.provenance : Made available in DSpace on 2013-07-17T18:17:59Z (GMT). No. of bitstreams: 1 WeeksLindaC1987.pdf: 220299 bytes, checksum: fc818c7de71d75a816432c9074f7e865 (MD5) Previous issue date: 1987-05-04

Relationships

Parents:

This work has no parents.

Last modified

Downloadable Content

Download PDF

Items