Semen Preparation

Once the semen has been collected and appropriately evaluated, it is ready for insemination of mares. Although not always necessary, adding an extender for insemination will optimize survival of sperm during the time needed to prepare the mare for breeding and will reduce contamination of the mare's uterus at breeding. This is especially important in mares susceptible to developing uterine infections after breeding. For immediate insemination, adding an equal volume of extender than that of semen (1:1 dilution ratio) is usually sufficient and does not require any special calculations.

As long as enough progressively motile sperm are present, the extended ejaculate is simply split between the number of mares to be bred, or the whole ejaculate is used to breed a single mare. The minimum insemination dose necessary to keep from compromising fertility rates is 500 million progressively motile sperm per mare. However, as much sperm as is available should be used for insemination.

Mare Preparation

Once it is ascertained that a mare (or group of mares) is ready for breeding, the mare's tail is wrapped and the perineal area around the vulva is thoroughly scrubbed and generously rinsed three times. Povidone iodine scrubs can be used for this purpose, but all residues should be thoroughly rinsed with water to avoid introducing this disinfectant into the uterus while inserting the pipette for insemination. After thorough scrubbing and rinsing, the perineal area is dried with clean paper towels. The mare is ready for insemination.

Insemination Procedure

In preparation for artificial insemination, the corresponding volume of extended semen is drawn into one or more syringes (with no rubber plunger) connected to a disposable long plastic pipette.

The veterinarian or manager performing the procedure should wear a clean plastic sleeve and a sterile glove on the hand that will be used to introduce the pipette into the uterus. The gloved hand may be lubricated with a water soluble sterile jelly to facilitate the procedure. Then, the pipette is cupped within this hand, and directed through the vulvar lips, vestibule, into the vagina, and then inserted through the cervix, while the opposite hand remains outside the mare to push the syringe plunger and inject the semen through the pipette. For successful insemination, the semen must be deposited inside the uterus.