Preserv Xtra is a long term extender that utilizes a particular buffer that can basically put the sperm cells to “sleep”. This is not the case for all boars, but certain boars are affected more than others.
When you check samples under a microscope, it is not unlikely that the cells may appear dormant and not moving. Ideally, the sample should be warmed to a body temperature of 36-37 degrees Celsius (96 degrees Fahrenheit) for about 15 minutes and normal cellular activity will resume. However, we realized that it may be difficult to use this method due to the lack of sufficient methods to properly warm samples. All the boar studs we work with have a quality control procedure. Semen from every batch is kept and quality is checked routinely through the life of the extender to ensure it’s quality. If you feel the need to check semen samples yourself, we recommend the use of a caffeinated coated slide to evaluate samples. Always check the sample before breeding or when you first open the tube. Never check samples after breeding.
Decreased cellular motility in un-warmed stored semen is normal and is actually beneficial to long term storage of semen because it conserves energy. Again, please place a drop of semen on a caffeinated coated slide to evaluate samples prior to breeding. This will immediately activate the cells without the need for warming. This is a very fast and efficient way to check motility. Please contact us for more details or to answer any additional questions you may have.