Related Experiment Video
Updated: Sep 21, 2025
11:10
Cryopreservation of Preimplantation Embryos of Cattle, Sheep, and Goats
Published on: August 5, 2011
30.9K
Success rate in a clinical equine in vitro embryo production program
1Department of Clinical Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, the Netherlands.
Theriogenology
|May 27, 2022
Summary
In vitro embryo production (IVEP) using Ovum Pick-Up (OPU) and Intracytoplasmic Sperm Injection (ICSI) is a successful breeding technique for Warmblood mares. This method addresses various reproductive challenges, yielding a high pregnancy rate and healthy foals, though a skewed sex ratio favoring colts is observed.
Area of Science:
- Equine Reproduction
- Assisted Reproductive Technologies
- Embryology
Background:
- In vitro embryo production (IVEP) via Ovum Pick-Up (OPU) and Intracytoplasmic Sperm Injection (ICSI) is increasingly utilized in Warmblood mares.
- This technique offers solutions for equine reproductive issues such as sub-fertility, poor semen quality, and synchronization challenges.
- IVEP provides practical advantages and a high success rate for breeding valuable mares.
Purpose of the Study:
- To evaluate the efficacy and outcomes of IVEP procedures in Warmblood mares.
- To assess the success rates of oocyte aspiration, blastocyst development, pregnancy establishment, and foal production.
- To identify factors influencing IVEP success and examine potential effects on foal sex ratio and health.
Main Methods:
- Performed 515 OPU-ICSI sessions, collecting immature oocytes for overnight shipment to a specialized laboratory.
- Analyzed the number of aspirated follicles, immature oocytes retrieved, and blastocysts produced per session.
- Tracked pregnancy rates following the transfer of cryopreserved IVP blastocysts and subsequent foal development.
Main Results:
- A mean of 25.9 antral follicles yielded 13.8 immature oocytes per session.
- 78% of procedures produced at least one blastocyst, with a mean of 2.12 blastocysts per session.
- Pregnancy rate after transfer was 77.7%, with approximately 60% of transferred blastocysts resulting in a foal. Gestation length and foal health were not significantly affected, but a male-biased sex ratio was noted in day 7 embryos.
Conclusions:
- IVEP is an effective breeding strategy for Warmblood mares, offering high success rates for blastocyst production and pregnancy.
- While IVEP does not negatively impact foal health or gestation, a potential bias towards male foals from early-stage embryos warrants further investigation.
- Owners should be aware of rare but potentially life-threatening complications associated with OPU procedures.
