ARTIFICIAL INSEMINATION OF THE MARE

The actual process of artificial insemination in a mare is not complicated, and can be learned very quickly. Unlike artificial insemination in cattle, which involves guiding the insemination pipette through the cervix via manipulation per rectum, equine AI is carried out completely vaginally. The equine rectum is not as durable as a bovines', and it is for this reason that rectal palpation by the lay person is not encouraged by most veterinarians and teaching facilities. In countries where international movement of cooled semen is easily achieved, all necessary health status documentation should be reviewed prior to insemination, and universally it is important to ensure that accompanying paperwork and/or semen identification confirms the identity of the stallion as being the correct one booked to breed the mare about to be inseminated - collection and shipping mix-ups do happen!!

The mare is preferably secured in stocks...The mare is preferably secured in a palpation chute (breeding stocks), and her tail is wrapped and deflected to one side where it should remain throughout the whole insemination process to avoid contamination of the scrubbed area. Insemination per vaginum does mean that one of the most important parts of the process is the preparation, during which the perineal area may be cleansed as for surgery most commonly using an iodine preparation such as "Betadine". There are however arguments to be made against the use of anti-bacterial agents, or even just soap. It has been shown that such washing of the stallion's penis with antibacterial agents or soap may result in removal of natural protective flora and result in a subsequent overgrowth of opportunistic pathogens (Bowen, J.M., Tobin, N., Simpson, R.B., Ley, W.B., Ansari, M.M. (1982) Effects of washing on the bacterial flora of the stallion's penis. Journal of Reproduction and Fertility, Suppl. 32:41-45). The same effect was subsequently seen following washing of the mare's perineum (Ley, W.B.), so in mares that are to be bred multiple times during a cycle, we recommend washing solely with clean water. This philosophy may also be extended to all mares being bred. The perineal area is scrubbed using a surgical preparation scrub technique, starting centrally, and working outwards. Once the outer (unscrubbed) section is reached, the disposable paper towel or cotton is discarded, and a new piece used to return to the center to scrub outwards again. The final scrub should involve a little greater pressure to remove any surplus surface scrub liquid remaining, so that it may not carried into the vagina during AI. The region may be blotted dry using a single pat with clean paper towel.

the semen is withrawn into the insemination syringe....
Once the mare is prepared, the semen is removed from the shipping container and the insemination sample is slowly drawn through the insemination pipette into the syringe. As elsewhere with the process, sterility is important here too. Note that nobody is touching the pipette, which once the syringe is filled will be placed back into its sterile packaging until it is later introduced into the mare's vagina in order to inseminate. If a "disaposable shipper" is being used, it is likely that the semen is shipped in a syringe, and all that needs to be done is to remove the sealing cap from the tip of the syringe and attach a pipette. Note that syringes used for insemination or shipping of semen should be all-plastic rather than having a rubber plunger, as with some stallions that rubber plunger or the lubricant covering it may be spermicidal.

using a gloved arm....with the thumb protecting the end of the pipette....Using a sterile lubricated gloved arm (a single-packaged sterilized glove may be used, or a glove from a regular box of gloves having been reversed to ensure maximum cleanliness), the inseminator will introduce their arm into the mare's vagina and identify the cervix - which should be found on the ventral (bottom) surface of the cranial (head-ward) portion of the vagina. The gloved thumb is placed over the end of the pipette prior to its introduction into the vagina. This prevents the pipette from picking up any contaminants which may subsequently be inseminated into the uterus along with the semen. The closer the mare is to ovulation, the more relaxed the cervix is likely to become. In the center of the cervix will be found a small depression, which is the opening to the uterus. One of the most apt descriptions of a cervix is that it is like a "small volcano" in shape protruding into the vagina. The inseminator will gently introduce the tip of the index finger through this depression, and then using the finger as a guide, slide the insemination pipette along it and into the uterus. It is important not to force the pipette at any point, as internal damage may occur if that is done, nor in most cases does the finger need to be introduced further than about the top knuckle (i.e. approximately 1 cm).

the syringe plunger is gently depressed, and insemination is complete. With the tip of the pipette introduced into the uterus approximately and inch, or as far as possible without any resistance being met (whichever is less), the plunger of the syringe is slowly depressed introducing the semen. Before removal of the pipette, the syringe may be unhooked and rehooked so that 2 cc of air may be introduced behind the semen in order to clear the pipette of the remaining semen (prior to drawing up the semen into the syringe, the plunger can be withdrawn slightly to achieve this effect, thereby preventing the need to unhook the syringe later). It is important that excess air is not introduced into the uterus, and a very small portion of the semen should remain at the very end of the pipette when it is removed from the uterus. The arm should then be slowly withdrawn from the vagina.

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