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ICSI Procedure Management
General Information
The emerging use of the ICSI (intracytoplasmic sperm injection) procedure in recent years has made this technique increasingly popular among breeders. At Royal Vista Ranch, ICSI candidates are managed until they are ready to be aspirated on-site to recover immature oocytes. Those oocytes are then sent to an ICSI lab that the mare owner has selected for maturation and injection. If an embryo or embryos are produced during this process they can be sent back to Royal Vista Ranch for transfer or frozen for use at a later time. This technology is proving to be a very valuable tool as an addition to assisted reproductive techniques.
Frequently Asked Questions
ICSI (Intracytoplasmic Sperm Injection) is an advanced breeding technique performed in a laboratory. During the process, a single sperm cell is carefully injected directly into a mare’s egg (oocyte). Once fertilized, the egg is cultured until it reaches the right stage of development, and the resulting embryo is then transferred into a recipient mare.
To perform ICSI (Intracytoplasmic Sperm Injection), a mare’s eggs (oocytes) must first be collected from her ovaries. This is done through a procedure called TVA (Transvaginal Aspiration). Using ultrasound guidance, a veterinarian gently inserts a needle through the vaginal wall to reach the follicles on the ovary. The needle is then used to draw out the follicular fluid and retrieve the oocytes.
Research and clinical experience show that repeated TVA does not harm the ovary or reduce a mare’s fertility in future heat cycles. While, like any medical procedure, there is a small risk of complications, serious issues are very rare, occurring in less than 0.3% of cases.
Embryo transfer (ET) is an excellent breeding option for healthy mares with normal reproductive tracts being bred to fertile stallions. However, ICSI (Intracytoplasmic Sperm Injection) can be a better choice in certain situations.
Mare factors: ICSI is often used for mares that have fertility challenges, especially when traditional embryo transfer attempts have not been successful. Mares with uterine problems or blocked oviducts may not be able to conceive or maintain an embryo long enough for it to be flushed for ET. Because ICSI bypasses both the uterus and the oviduct, it provides a valuable alternative for these mares. ICSI is also ideal for younger mares that are still competing, since eggs can be collected at any time of year—even during the off-season—minimizing time away from training. In some cases, if a mare passes away unexpectedly, her oocytes can be collected post-mortem to preserve her genetics.
Stallion factors: ICSI is frequently chosen when working with stallions that have a limited supply of semen, reduced semen quality, or are deceased. Since ICSI uses only a single sperm cell per oocyte (compared to millions needed for conventional embryo transfer), it allows breeders to make the most of rare or valuable semen doses.
Management advantages: ICSI gives breeders incredible flexibility. Mares don’t need to be cycling to collect eggs, and embryos created through ICSI can be frozen and transferred later—whenever the timing is best for an optimum foaling date. Each TVA session can also produce multiple embryos, sometimes even using semen from different stallions, allowing breeders to transfer one and freeze others for future use.
ICSI success can vary depending on several factors, including the mare’s age and overall health, the number and quality of oocytes collected, semen quality, recipient mare condition, and the experience level of the veterinarian aspirating and the laboratory performing ICSI.
On average, about 30% of injected oocytes develop into transferable embryos. Of those embryos transferred, roughly 80% result in a 12-day pregnancy. However, ICSI-produced embryos do have a slightly higher risk of pregnancy loss compared to traditional embryo transfer.
Overall, breeders can expect that about 60–70% of TVA (oocyte collection) sessions will produce at least one embryo suitable for transfer.
Yes, it’s possible to determine an embryo’s gender before transfer, but it requires a specialized laboratory. A small biopsy of the embryo is taken to test its chromosomes (XX or XY). The embryo can then be frozen and transferred once the desired gender is confirmed, though this process can slightly reduce pregnancy success rates.
Alternatively, the foal’s gender can be determined later by ultrasound, usually around 60 to 120 days of gestation, with good accuracy.
It may soon become possible to breed a mare with semen that has been sorted to produce only the desired gender. This technology is not widely used but may become more commonplace in the near future.
When your mare arrives at RVR, she’ll first have an ultrasound exam to check the number and size of follicles (which contain the oocytes) on her ovaries. The ideal candidate for transvaginal aspiration (TVA) of her oocytes typically has at least ten follicles under 30 mm in size.
Once we confirm your mare has a good number of suitable follicles, we’ll schedule a TVA appointment with an experienced veterinarian. The procedure usually takes less than an hour. Before starting, your mare will receive a brief health check and then be sedated for comfort. The TVA is performed while the mare stands quietly in the stocks.
After the procedure, antibiotics and anti-inflammatory medication are given to help prevent infection and reduce any discomfort.
The veterinarian will then carefully transport any recovered oocytes to the reproductive laboratory, where they’ll be incubated and injected with sperm (ICSI). Once the resulting embryos reach the right developmental stage, they can either be frozen for future use or shipped to a recipient facility of your choice for transfer.
Yes! One of the major advantages of ICSI is that the embryos can be frozen and stored indefinitely. Because TVA and ICSI can be done at any time of year, breeders have the flexibility to create embryos when it’s convenient and transfer them later when an ideal recipient mare is available.
Pregnancy rates from frozen-thawed ICSI embryos are only slightly lower than those from fresh transfers, making freezing a safe and practical option for long-term breeding plans.
Frequently Asked Questions
ICSI (Intracytoplasmic Sperm Injection) is an advanced breeding technique performed in a laboratory. During the process, a single sperm cell is carefully injected directly into a mare’s egg (oocyte). Once fertilized, the egg is cultured until it reaches the right stage of development, and the resulting embryo is then transferred into a recipient mare.
To perform ICSI (Intracytoplasmic Sperm Injection), a mare’s eggs (oocytes) must first be collected from her ovaries. This is done through a procedure called TVA (Transvaginal Aspiration). Using ultrasound guidance, a veterinarian gently inserts a needle through the vaginal wall to reach the follicles on the ovary. The needle is then used to draw out the follicular fluid and retrieve the oocytes.
Research and clinical experience show that repeated TVA does not harm the ovary or reduce a mare’s fertility in future heat cycles. While, like any medical procedure, there is a small risk of complications, serious issues are very rare, occurring in less than 0.3% of cases.
Embryo transfer (ET) is an excellent breeding option for healthy mares with normal reproductive tracts being bred to fertile stallions. However, ICSI (Intracytoplasmic Sperm Injection) can be a better choice in certain situations.
Mare factors: ICSI is often used for mares that have fertility challenges, especially when traditional embryo transfer attempts have not been successful. Mares with uterine problems or blocked oviducts may not be able to conceive or maintain an embryo long enough for it to be flushed for ET. Because ICSI bypasses both the uterus and the oviduct, it provides a valuable alternative for these mares. ICSI is also ideal for younger mares that are still competing, since eggs can be collected at any time of year—even during the off-season—minimizing time away from training. In some cases, if a mare passes away unexpectedly, her oocytes can be collected post-mortem to preserve her genetics.
Stallion factors: ICSI is frequently chosen when working with stallions that have a limited supply of semen, reduced semen quality, or are deceased. Since ICSI uses only a single sperm cell per oocyte (compared to millions needed for conventional embryo transfer), it allows breeders to make the most of rare or valuable semen doses.
Management advantages: ICSI gives breeders incredible flexibility. Mares don’t need to be cycling to collect eggs, and embryos created through ICSI can be frozen and transferred later—whenever the timing is best for an optimum foaling date. Each TVA session can also produce multiple embryos, sometimes even using semen from different stallions, allowing breeders to transfer one and freeze others for future use.
ICSI success can vary depending on several factors, including the mare’s age and overall health, the number and quality of oocytes collected, semen quality, recipient mare condition, and the experience level of the veterinarian aspirating and the laboratory performing ICSI.
On average, about 30% of injected oocytes develop into transferable embryos. Of those embryos transferred, roughly 80% result in a 12-day pregnancy. However, ICSI-produced embryos do have a slightly higher risk of pregnancy loss compared to traditional embryo transfer.
Overall, breeders can expect that about 60–70% of TVA (oocyte collection) sessions will produce at least one embryo suitable for transfer.
Yes, it’s possible to determine an embryo’s gender before transfer, but it requires a specialized laboratory. A small biopsy of the embryo is taken to test its chromosomes (XX or XY). The embryo can then be frozen and transferred once the desired gender is confirmed, though this process can slightly reduce pregnancy success rates.
Alternatively, the foal’s gender can be determined later by ultrasound, usually around 60 to 120 days of gestation, with good accuracy.
It may soon become possible to breed a mare with semen that has been sorted to produce only the desired gender. This technology is not widely used but may become more commonplace in the near future.
When your mare arrives at RVR, she’ll first have an ultrasound exam to check the number and size of follicles (which contain the oocytes) on her ovaries. The ideal candidate for transvaginal aspiration (TVA) of her oocytes typically has at least ten follicles under 30 mm in size.
Once we confirm your mare has a good number of suitable follicles, we’ll schedule a TVA appointment with an experienced veterinarian. The procedure usually takes less than an hour. Before starting, your mare will receive a brief health check and then be sedated for comfort. The TVA is performed while the mare stands quietly in the stocks.
After the procedure, antibiotics and anti-inflammatory medication are given to help prevent infection and reduce any discomfort.
The veterinarian will then carefully transport any recovered oocytes to the reproductive laboratory, where they’ll be incubated and injected with sperm (ICSI). Once the resulting embryos reach the right developmental stage, they can either be frozen for future use or shipped to a recipient facility of your choice for transfer.
Yes! One of the major advantages of ICSI is that the embryos can be frozen and stored indefinitely. Because TVA and ICSI can be done at any time of year, breeders have the flexibility to create embryos when it’s convenient and transfer them later when an ideal recipient mare is available.
Pregnancy rates from frozen-thawed ICSI embryos are only slightly lower than those from fresh transfers, making freezing a safe and practical option for long-term breeding plans.
