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Kenney Extender


The Kenney Extender includes the extender packet and one liter of Sterile Water for Irrigation USP for a cost of $26.00. Buy Now

Depending on the ejaculate volume, concentration and number of mares bred per ejaculate, the one liter volume should serve between 5 and 10 separate collections. It does not include antibiotics.

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About Kenney Extender

One of the most reliable and trusted extenders is Kenney Extender, developed by Dr. Robert Kenney of New Bolton Center, University of Pennsylvania. Kenney Extender is a glucose-skim milk extender, which has been shown to work extremely well for transported semen.

Our Kenney Extender is available in a one liter size and includes an extender packaet and one bottle of Sterile Water for Irrigation USP. After mixing the contents of the packet with the sterile water, the extender may be separated into 100 or 200 ml aliquots, antibitoics added and frozen for up to 2 months.

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Why Extender is Critical

Since the undiluted seminal plasma is harmful to the sperm, the use of an extender is critical when shipping stallion semen. If an extender is not used, stallion sperm normally will not survive more than a few hours.

About Diluting

It is also important that enough extender is used when diluting stallion semen. The typical insemination dose contains a concentration of 40 - 50 M/ml of sperm. When shipping stallion semen, best survivability is obtained when a minimum dilution of 3 parts extender to 1 part semen is used. However, with low concentration ejaculates, this dilution may result in an insemination dose concentration below the optimal range. If you dilute at a ratio of 2 part extender to 1 part semen and experience low survivability, you may want to extend at the 3:1 ratio and ship a higher dose volume.

Try our Javascript Semen Dilution Calculator!

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Antibiotics Should be Added

Good practice also requires the addition of an antibiotic to the extender. Because the semen from different stallions may have adverse reactions to different antibiotics, we do not add antibiotics to the Kenney Extender that we sell. In this way, you can use the antibiotic that works best for your stallion.

When choosing an antibiotic to use, there are several different factors to consider. Cultures must be taken to determine if pathogenic bacteria are present and sensitivities of bacteria to antibiotics must be determined. It is also a good idea to compare survival of sperm using different types of antibiotics. We recommend that you consult with your veterinarian in selecting the appropriate antibiotic.

Many antibiotics are highly toxic to sperm. This toxicity shows up particularly during the storage of semen. Because of this, when testing stallion semen for survival of sperm, both 24-hour and 48-hour motility evaluations should be performed.

Click here for a list of antibiotics that have been found least detrimental to stallion sperm.

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