Semen Assessment Webinar
What a fantastic honor to join the dream team ( Bart Kools and Tullis Matson) to talk about Semen Assessment and Preparing your stallion for the breeding Season. For those of you who missed these fantastic Webinars Tullis Talks about from British Breeding, you can still watch them:
Is it possible to freeze sperm from the epididymis? Yes with a certain technique this is certainly possible! But why would you freeze from the epididymis? Now there are a few possibilities, why you could choose this technique:
The technique can be used following routine castration, upon death of the animal or where the testes have suffered a severe trauma or testicular torsion. But also in case of routine castration, e.g. if the stallion is not manageable, but you still want to have the possibility to use your stallion for breeding in the future, this technique offers a last chance to save the sperm when there is no other option available.
The epididymis can be thought of as a storage organ for sperm before ejaculation and it is comprised of three sections : the caput (head), corpus (body) and cauda (tail).
Transit time for spermatozoa through the epididymis is about 8-11 days, during this time they undergo significant maturation. As they pass through the epididymis fluid is resorbed and the epididymis also provides its own secretions, influencing the membrane properties of the spermatozoa. Sperm that leave the testis are immotile and incapable of fertilization, however by the time they reach the tail of the epididymis they have achieved the ability to fertilize.
Whilst epididymal semen extraction is a highly beneficial method of extracting semen in non-planned emergency situations, it is not recommended as an alternative to ejaculated semen freezing. Due to the factors that can affect the semen quality, it should be viewed as a last chance method of semen harvesting. If situations permit for collection and freezing of ejaculated semen prior to castration of the stallion, this should always be recommended as the primary course of action.
The success of this procedure is very much dependent on the speed at which the testes are transported to Pasedes from the time the animal was castrated or the time of death. It is important that the testes are washed and packaged correctly.
If you are interested in more information about this technique, you can always contact us!
Vitamins and minerals
Is it advisable to feed your stallions vitamins and minerals? Yes, it provides stallions with nutrients needed to develop sperm with strong intact cell membranes and can improve motility and viability. In old age stallions also produce less vitamins themselves, this has to do with the decline of the immune system in terms of age. But don’t underestimate training, medication and stress even in younger stallions. Feeding extra vitamins and minerals can have an influence on the health of the stallion and indirectly on the sperm.
Equine testicles consist of long, very complicated tubes/channel called ‘seminiferous tubules’ and interstitial tissue. Within the seminiferous tubules are the Sertoli’s cells. These are responsible for the production of sperm cells. Within the interstitial tissue are the cells of Leydig. They are involved in the production of testosterone; the hormone that, among other things, provides the stallion’s external characteristics and typical stallion behaviour.
If the base is good; that is, if the stallion has not been ill for the last two months, had no antibiotics, no stress, and the stallions is in shape, looks fantastic in his skin and has covered the last two months with regularity; then vitamins and minerals are good for the protection of the stallion as well as for the semen. But if the base is good, you can use vitamins and minerals to keep protecting the stallion and sperm, but you shall not to improve it. However, you can find improvement when the stallion is older than fifteen years, and he will show signs of aging. Then vitamins and minerals have a very positive effect. Semen from stallions from the age of fifteen will remain the same or become less of quality.
Now there are many vitamins and minerals described that can have an identical effect, but it’s all about the right combination. Semen development of the stallion is very complex and takes an average of 57 days, so if you starts to add vitamins and minerals, do not expect a result within a week. But it is certainly never too late to start! If there are any questions, please feel free to contact us.
Equine seminal plasma
Seminal plasma consists of secretions from the accessory gonads in the stallion’s reproductive system.
During ejaculation, sperm cells are mixed with fluid from the accessory gonads. In addition to providing sperm transport, seminal plasma can play an important role in stabilizing sperm membranes, protecting sperm from the mare’s immune system, and binding to the egg cell.
However, seminal plasma from some stallions can be somewhat toxic to their own sperm. In natural covering, the time frame is fairly short, but if you consider what happens when the sperm is prepared for artificial insemination, then seminal plasma is exposed to the sperm for a longer period of time, a situation that does not occur in natural covering. Prolonged exposure to large amounts of seminal plasma can be detrimental to sperm during storage, either chilled or frozen. A extender dilutes the potential toxic effects of the seminal plasma and centrifugation can be used to remove most or all of the seminal plasma and then further dilute for the desired final result.
Anyone who works with live animals knows that not everything goes by the book. For example, with stallions and the processing of their sperm, things can turn out differently than you had in mind. Abnormalities can occur, but the question is mainly: how did it originate and what can you do about it?
Below are some examples of abnormalities in stallions:
- Blocked ampull
This is mainly recognizable by buttery thick spermatozoa, stuck to the inside of AV. It can even start with an ejaculate without sperm.
- Testicular degeneration
Another abnormality is testicular degeneration. Testicular degeneration is a major cause of subfertility and infertility in stallions. Testicular degeneration can have several causes such as:
- Toxic substances
- Vascular disease
- Age-related degeneration
- Local infections etc.
Testicular degeneration may be transient or permanent.
Rotation of testicles
Rotation of testicles less than 180 degrees often does not result in overt clinical symptoms. Nevertheless, research has shown that the blood supply in the testicle has changed slightly. In rotation of testicles of more than 180 degrees, the blood supply in the testicle is severely reduced. These cases often show clinical symptoms such as colic accompanied by enlarged painful testicles, enlarged scrotum, etc.
References: I am a big fan of Dickson Varner, Professor of Equine Theriogenolgy & Pin Oak Stud Chair of Stallion Reproductive Studies and Angus Mc Kinnon, owner of Gouldburn Valley Equine Clinic. If I mention or refer to a research afterwards, these are research by Drs. Dickson Varner, or Drs. Angus Mc Kinnon
How often do you hear it; in case of problems turn back to the basic. With sperm processing of stallions works that exactly , and the basic here is, of course, the stallion.
Is the stallion comfortable in his skin? Does he look good? Is he not too fat? The last two months had no fever? (often when there are many loose heads in the ejaculate, this may be an indication that the stallion has had a fever). Does he suffer from stress? How is he with collecting? Does he suffer from pain? There are many factors that can affect sperm quality, but always start at the base! The stallion himself.
A stallion is the most fertile in his younger years, on average 4–7 years. Up to the age 13-14, the sperm quality can be improve, but once a stallion is 15 years of age or older, the sperm quality can remain the same or becomes less. Especially in older stallions, adding vitamins and minerals often has a positive effect. Do not expect immediate results, it needs at least 6-8 weeks to see the effect.
The reason for poor libido, or lack of achievement of an erection or ejaculation in an experienced stallion is often complicated and therefore important to track the background factors and/or disease processes that may contribute to the problem. Some stallions that have painful hind/legs/joints, and or pain in the back, associate pain with covering. For these, often somewhat older stallions, ground collection could be a solution.
Angus mc Kinnon has a fantastic quote, one that in my opinion can not be said often enough: “People believe that the stallion is just a sperm producing machine, they have little thought for the normal horse behaviour.” If the production and libido of the stallion is not high, only an custom management will work.
Good luck with the breeding season!!