What is ICSI??

For you academics, ICSI is short for Intra Cytoplasmic Sperm Injection.  It is the process of removing the oocyte (egg) from the follicle on the ovary of a mare (aspiration), manually injecting a sperm into that egg with very tiny tools on a very high powered microscope (micromanipulators), then growing the injected egg in a special incubator (triple gas) until an embryo develops (about 9 days later).

Why do ICSI?

ICSI has two applications:
MARE PROBLEMS – When mares have problems in their reproductive tract – torn or fibrosed cervix, chronic infection with bacteria or fungus, persistent fluid, chronic endometritis, plugged oviducts, failure to maintain a pregnancy, poor biopsy score, third degree perineal lascerations or unexplained failure to recover an embryo, ICSI is an option because it totally bypasses the problems in the reproductive tract and goes directly to the ovary.                                                                                                                   Another advantage of ICSI is the frequent production of multiple embryos from a single aspiration. Some mares respond better to the ICSI process than others, however  it is not uncommon for 3 to 6 embryos to develop.  The batch can be split if there are enough eggs and more than one stallion can be used.  Our best result to date was 11 embryos from 3 different stallions out of one batch of eggs.

STALLION PROBLEMS – The fact that ICSI uses only one sperm to fertilize an egg is the biggest advantage of ICSI.  When the semen is gone, the breeding stops. Whether the stallion dies, goes sterile, or all the frozen semen is used up that genetic contribution is done.  However, with ICSI, one straw of frozen semen can prolong the breeding live of a stallion for years to come. There are about 125 million sperm cells in one frozen straw and depending on the stallion, 10 to 35% of those sperm will be alive when that semen is thawed.  A standard breeding dose of frozen semen to breed a mare one time is 8 straws or 1 billion sperm cells.  A standard breeding dose to inject a batch of eggs is 1/50 of a straw, which will inject hundreds of eggs if that many eggs were collected from multiple mares on a single day.  Additionally, for some fertility problems in stallions – low motility, low sperm numbers, acrosome defects or reactions to their frozen semen – the ICSI option frequently solves the problem.  


What type of mares are good ICSI candidates?

Any mare can be used as a donor for ICSI, however, in general, mares in their late teens produce less follicles, less often, and the eggs are less fertile.  We have had very little success with mares over 25 yrs. 

 That said, some young mares do not do well with the ICSI process. About 5 to 10% of mares are very difficult to get an ICSI embryo, but some mares consistently produce multiple embryos.

At what age can you start ICSI?

We have  produced many ICSI embryos from 2 yr old fillies.

Do I have to bring my mare to you to perform all ICSI services?

No, there are many veterinarians around the country now that can aspirate eggs from mares and send them to an ICSI laboratory.  

We do aspirate here, inject the eggs, mature them in the incubator and transfer them into recipient mares. 

Can I use one of my own mares as a recipient mare?

With the success of freezing ICSI embryos, we can now transfer your embryo into your mare. Whether the donor mare or your recipient mare, the embryo seldom develops on the day the recipient is ready to receive it. However, once the embryo is frozen, it can be thawed and transferred when the recipient mare is ready. 

What if my mare has multiple ICSI embryos?

You have a choice – transfer or freeze.

TRANSFER – transferring a fresh embryo requires a recipient mare that ovulated 4 to 5 days ago for a successful transfer. If there is one available,  either from our herd, your own recipient or another ET facility, a fresh transfer is possible.

FROZEN – freezing ICSI embryos has become a very successful option if done properly.  Since moving to Texas, we have learned that thawing and shipping frozen embryos to another facility does not work well. However, when embryos are thawed in our lab and transferred here without shipping them, the pregnancy rates are equal the the pregnancy rates of fresh ICSI embryos.

We can’t directly transfer an embryo into the mare we just flushed. There usually is a small amount of residual fluid in the uterus from flushing the embryo. This doesn’t create the best environment for the embryo to survive in. You would want to freeze the embryos, recycle your mare and transfer them when she and the recipient are ready.

How soon can I take my recipient mare after she’s confirmed pregnant?

She is considered safely in foal at 45 days. During this time, when she is at the clinic, we will perform periodic pregnancy checks and she will be on a daily progesterone supplement, Regu-mate. When she is confirmed pregnant at 45 days, you may take her home that day. Recipients can be taken sooner at the owners discretion.

If I don’t want to keep my recipient mare, can I bring her back for a refund?

Yes. We will perform a breeding soundness exam and if we can use her in the embryo program again, you will receive a $500 refund if they are still breeding sound.

Do I have to keep my recipient mare on Regu-mate for the entire pregnancy?

We highly suggest keeping the recipient mare on Regu-mate until at least 120 days regardless of her own progesterone level.

What is the cost of doing an embryo transfer?

The cost can vary. If we’re doing all the breeding, it can run approximately $4000-$4500. The main cost is leasing the pregnant recipient which is $1500. You also have the option of a transported embryo where you have someone else do the breeding and they send the embryo to us or we can flush it here. Either way, we would need to know exactly when the mare ovulated. That cost is approximately $3000 – $4500 depending on whether we board the mare, breed her and flush her here or if you just send us the embryo to transfer.

*Please e-mail us if you would like any packet information sent to you.