SEMEN COLLECTION - EQUINE ARTIFICIAL INSEMINATION

Semen Collection and evaluation is an important part of breeding management whether you are using natural service or artificial insemination.

Semen collection of a stallion used for natural service allows assessment of:-

• Semen characteristics such as proximal droplets indicating overuse; bent tails; displaced heads; urine, blood etc.
• Percent of sperm which are alive (live/dead). Total sperm numbers per ejaculate on average.
• Daily sperm output. These last two characteristics allow determination of how much you can use the stallion (ie 3 - 4 times daily) and ultimately the size of his book of mares.
• The longevity of the semen at body temperature. This determines if mares need to be crosscovered if they are slow to ovulate.
• Normal gel volume.
• Urethral pulsations at ejaculation. This allows further assessment of whether a proper ejaculation has occurred when monitoring natural service.
• Size of the penis. Allows assessment of whether caslicks need to be opened for service.
• Semen culture. Culturing semen for bacterial infections allows diagnosis of possible sexually transmitted diseases (STD's) and assessment of the best form of routine post cover antibiotic infusion into the uterus.

With artificial insemination many of the same characteristics need to be assessed. This allows determination of:-

• Number of times the ejaculate can be divided between mares and still maintain adequate fertility.
• The maximum time for storage post collection before insemination.
• The best extender to be used for chilled semen. Collected semen can be assessed against a large number of different extenders to determine which allows the maximum storage time and optimum fertility.
• Semen culture determines which antibiotic is best used in the extender.
• Daily sperm output again determines the optimum number of collections per day.
• Suitability of semen for freezing.

Semen evaluation is therefore a very important management tool for both natural service and artificial insemination.