– a vital breeding factor!

By Jamie Anderson, MA Physiol (Oxon)

Preventing contamination of semen during collection and processing can really help with fertility rates!

Over the last two seasons, we’ve noted that hygiene in AI programmes is often distinctly poor. Poor hygiene can negatively impact semen quality, fertility rates in mares, and also potentially lead to the transmission of previously undetected venereal diseases! So here are the steps you can take to boost your success rates!

Clean Penises…

A stallion’s penis is generally pretty grubby at best. Although the penis has a natural (and harmless) bacterial population (or flora), it can also potentially harbour nasty bacteria or other pathogens, as well as dirt, grit, hay, straw, smegma. If these pathogens or irritants make their way into the collected semen, then they can potentially cause problems once inseminated. Older mares and those with delayed uterine clearance (DUC) will be particularly at risk. But any contaminants could potentially reduce fertility rates in any age of mare. It is important to clean the stallion’s penis regularly, and at the very least each time before semen is collected. Whilst the washing should remove debris from the penis, it is important not to disturb the natural flora on the surface of the penis. Use of antimicrobials (iodine, chlorhexidine, skin cleansers etc.) is not recommended, as disruption of the natural flora may allow opportunistic pathogens to infect the penis (and possibly the internal genital tract). These opportunistic infections are usually very difficult to clear. The trick is to use clean water, and nothing else. After washing your own hands, and rinsing and drying them thoroughly the stallion should be teased until he has a full erection. Using clean warm water, the penis should be thoroughly but gently cleaned, rinsed, and gently patted dry with clean paper towel. It is important that this cleaning is performed prior to every semen collection. If your stallion does not like having his penis washed, then firmly but safely teach him that he has to put up with it! If you’re really struggling try making the water even warmer – most stallions will appreciate 45-50°C water! As always, when working with stallions; take care!

Cleaning for dummies

Think about it. Your stallion, or multiple stallions jump on your dummy mare every week during breeding season. Each stallion will have bacteria (and potentially other pathogens) living all over his body. Hooves, legs, chest, face, head and neck… not just on his penis. When he mounts it, the dummy tends to get wet and greasy. Pre-ejaculate, sweat, saliva, hair, sebum and other debris may well be left on the dummy. Pathogens then live (and potentially) grow on the surface of the dummy and can potentially contaminate collected semen.

So, what can we do?

Clean the dummy after every collection using a strong antimicrobial cleaning product such as Virkon.

  1. Rinse the dummy completely using clean water. It is possible that if any cleaning product is left on the surface it could contaminate the semen and potentially damage or kill the sperm cells in the ejaculate.
  2. Dry the dummy thoroughly
  3. Wrap the end of the dummy in catering cling film before each collection. This will provide an aseptic surface on the “working” end, and help prevent soiling of the dummy and contamination of the stallion’s penis and or any semen that is collected.

Liners, Gloves and Sandwich Bags…

Would you wash-out and re-use a condom? Hopefully the answer you immediately give is no. (If you answered yes, there’s not a lot we can do to help you, I’m afraid). It always amazes me when people don’t use disposable liners when collecting semen. There is a bit of a myth that goes around that “some stallions won’t collect with a plastic liner”. In our experience, and also in the vast experience of Jos Mottershead and Kathy St. Martin of, pretty much any stallion will happily collect with a disposable liner. Using a disposable liner avoids the worry of contamination between stallions, and avoids the need for multiple AVs (one for each stallion at some studs we visit), or huge amounts of washing and decontamination between uses. It is also important to wear new disposable gloves for each collection. We also strongly recommend using disposable collection bottle liners. These can either be baby bottle liners, sandwich bags, or whatever aseptic, dry, disposable and watertight plastic bag you can find that would be suitable. If you’re re-using plastic (or even glass) collection bottles, it can be all too easy to leave behind dirt, pathogens, and residues that may be spermicidal.


In-line filtration is a very important part of the collection process, and not just to prevent the spermotoxic gel fraction (final part of the ejaculate) getting into the collection! Even after careful washing, smegma, dirt, and other matter can be shed from the penis during collection. Rather than allow these contaminants to pass into the collection vessel together with the semen, it is preferable to filter them out during collection using an in-line milk (or nylon mesh) filter. This prevents contaminants becoming mixed into (and possibly dissolved in) the semen.

Extenders and antibiotics

Your choice of semen extender will be crucial in achieving decent fertility rates. Although extenders without antibiotics are available, we would not recommend that they are used unless the stallion’s sperm do not survive well when exposed to antibiotic agents. Most commercially available semen extenders contain antibiotics, although not always in the most effective combinations. For instance, one of the most popular commerically available semen extenders has been shown in tests to have a poor antibacterial action, and so should have additional anitbiotics added to it. If you are unsure, ask a specialist stud vet or collection centre for help! Semen that is collected and processed properly and as aseptically as possible will almost certainly improve fertility rates that you experience. If you’re a mare owner that is looking to use artificial insemination – ask the stud about their hygiene procedures. And stallion owners and collection centres – boast about the cleanliness and special procedures that are in place where your stallion’s semen is collected!

© 2012, LLC
Use of article permitted only upon receipt of required permission and with necessary accreditation.
Please contact us for further details of article use requirements. Other conditions may apply.

Return to Articles Page

Return to Main Page