In this study, we evaluated the meiotic competence of equine oocytes from ovaries preserved for one day. We also investigated fertilization, cleavage rate, developmental competence and freezability of equine embryos after intracytoplasmic sperm injection (ICSI). After collection from ovaries, the oocytes were classified into two groups comprised of those having compact cumulus layers (Cp) or those having expanded cumulus layers (Ex). Oocytes with a first polar body were subjected to fertilization by ICSI using frozen-thawed stallion spermatozoa and were then cultured in CR1aa medium. The rates of metaphase II-stage oocytes, normal fertilization and cleavage were not significantly different between the two oocyte categories (38.5, 70.0 and 48.7% for CP and 43.5, 60.0 and 58.8% for Ex, respectively). However, the blastocyst development rate of Ex was significantly (P<0.05) higher than that of Cp (25.5 vs. 7.7%). Three Cp-derived and 12 Ex-derived early blastocysts were cryopreserved using the slow cooling protocol, and all of them developed to hatching blastocysts after thawing. These results suggest that equine oocytes fertilized by ICSI can develop to the preimplantation stage in culture conditions similar to those used in the bovine. Furthermore, the Ex oocytes had higher developmental competence than the Cp oocytes, and the in vitro-produced blastocysts had high viability after freezing and thawing.
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http://dx.doi.org/10.1262/jrd.18167 | DOI Listing |
J Equine Vet Sci
January 2025
Department of Clinical Studies - New Bolton Center, University of Pennsylvania School of Veterinary Medicine, 382 West Street Road, Kennett Square, PA, 19348.
Transvaginal ultrasound-guided follicle aspiration (TVA) is being performed frequently in equine practice, to recover oocytes for in vitro embryo production via intracytoplasmic sperm injection. While complications from TVA are rare, one of the most prevalent major complications is formation of an ovarian abscess, which can result in the necessity for euthanasia. The acute-phase serum proteins, fibrinogen and serum amyloid A (SAA) are markers of inflammation that might be of use in diagnosis of ovarian abscess.
View Article and Find Full Text PDFJ Equine Vet Sci
January 2025
Veterinary Reproduction Group, Faculty of Veterinary Medicine, University of Cordoba, Spain. Electronic address:
Sperm vitrification is an alternative freezing method, which includes high cooling rates and non-permeable cryoprotectants agents. The first attempt in equids was using the spheres technique by directly dropping small volumes of the sperm into liquid nitrogen. Later, vitrification was developed using 0.
View Article and Find Full Text PDFTheriogenology
December 2024
Equine Fertility Group, Facultad de Veterinaria, Universidad Cardenal Herrera-CEU, CEU Universities, Alfara Del Patriarca, Spain. Electronic address:
The objectives of this study were to investigate the influence of different OPU variables (vacuum and injection pressures during follicle aspiration and flushing, needle twisting to scrape follicles, number of follicle flushes and type of flushing media) on oocyte recovery rate (ORR) and morphology. Overall, 120 postmortem excised ovaries were processed in 62 replicates (1.9 ± 0.
View Article and Find Full Text PDFOpen Vet J
November 2024
Theriogenology Department, Faculty of Veterinary Medicine, Cairo University, Giza, Egypt.
Background: Senility influences fertility in women and companion animals, especially horses.
Aim: This study aimed to investigate the effect of aging in horses on the daily changes in the dominant follicle (DF) dynamics and hemodynamics, antimüllerian hormone (AMH), enzymes, antioxidants, and ovarian hormones during the estrous cycle.
Methods: Ovaries of old mares ( = 5, age >20 years) and young native mares ( = 6, age <10 years) were scanned during 6 different estrous cycles from March 2022 to August 2023 with Doppler ultrasound.
Tissue Cell
November 2024
Department of Biomedical Sciences and Pathobiology, Center of Pathobiology, University of Veterinary Medicine, Vienna, Austria; VetCore Facility for Research, University of Veterinary Medicine, Vienna, Austria. Electronic address:
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