Comparison of the effects of eFSH and deslorelin treatment regimes on ovarian stimulation and embryo production of donor mares in early vernal transition

T. Raz*, S. Carley, C. Card

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

15 Scopus citations

Abstract

The objective was to compare the effects of eFSH and deslorelin treatment regimes on ovarian stimulation and embryo production of donor mares in early spring transition. Starting January 30th, mares kept under ambient light were examined by transrectal ultrasonography. When a follicle ≥25 mm was detected, mares were assigned to one of two treatment groups, using a sequential alternating treatment design. In the eFSH group, mares (n = 18) were treated twice daily with eFSH (12.5 mg im) until they achieved a follicle ≥35 mm; hCG was given 36 h later. In the deslorelin group, mares (n = 18) were treated twice daily with deslorelin (63 μg im) until a follicle ≥35 mm was detected, and then they were given hCG. Estrous mares were inseminated with fresh semen. Eight days after ovulation, embryo recovery attempts were performed. In each group, 14/18 (78%) mares ovulated following the eFSH or deslorelin treatment regimes. The mean (95% CI) interval from treatment initiation to ovulation was 8.2 d (7.3, 8.9) and 7.2 d (6.2, 8.1) in the eFSH and deslorelin groups, respectively. In the eFSH group, the number of ovulations was significantly higher (mean ± S.E.M.; 3.4 ± 0.4 vs. 1.1 ± 0.1 ovulations), and more embryos were recovered (2.6 ± 0.5 vs. 0.4 ± 0.2 embryos/recovery attempt). We concluded that eFSH and deslorelin treatment regimes were equally effective in inducing ovulation in early transitional mares, within a predictable time of treatment; however, the eFSH regime increased the number of ovulations and embryos recovered per mare.

Original languageAmerican English
Pages (from-to)1358-1366
Number of pages9
JournalTheriogenology
Volume71
Issue number9
DOIs
StatePublished - Jun 2009
Externally publishedYes

Bibliographical note

Funding Information:
This study was supported by the Equine Health Research Fund of the University of Saskatchewan. The authors thank BET Pharm for providing Deslorelin, Intervet Canada Ltd. for providing Chorulon ® , and Pharmacia Animal Health for providing Lutalyse ® . Special gratitude to Ms. Susan Cook from the WCVM endocrinology laboratory for her expertise, and to Mr. Jeffrey Bergermann for technical help.

Keywords

  • Deslorelin
  • Embryo transfer
  • Superovulation
  • Transitional mare
  • eFSH

Fingerprint

Dive into the research topics of 'Comparison of the effects of eFSH and deslorelin treatment regimes on ovarian stimulation and embryo production of donor mares in early vernal transition'. Together they form a unique fingerprint.

Cite this