Sperm selection using single layer centrifugation prior to cryopreservation can increase thawed sperm quality in stallions.

REASONS FOR PERFORMING STUDY The increasing use of modern reproductive techniques in human medicine has led to a higher demand for isolation of motile sperm. Several of these isolation techniques have been adapted for veterinary use and can be applied for the selection of a superior sperm sample from stallion semen. Until recently a major disadvantage of such isolation techniques was the limitation in sperm volume that could be handled. Androcoll-E had been shown to be successful for processing large volumes of equine semen but there are few data to substantiate the potential beneficial effect of freezing an Androcoll-E selected equine sperm sample to obtain higher quality following thawing. OBJECTIVES AND METHODS In this study, the effect of Androcoll-E treatment of sperm prior to cryopreservation was compared with cushioned centrifugation using ejaculates from 8 different stallions selected because they were known to have semen of differing quality following freezing. RESULTS Androcoll-E treatment increased measures of semen quality prior to freezing. However, Androcoll-E treatment reduced the yield of sperm following centrifugation when compared with the cushion centrifuged control group (50.9 ± 14.2% vs. 97.1 ± 9.0%, respectively). Quality analysis following thawing showed an overall improved sperm quality for Androcoll-E treated samples and average post thaw progressive motility (PM) was 41.6% compared with 30.5% for the cushion centrifuged group. CONCLUSIONS AND POTENTIAL RELEVANCE Androcoll-E can be used with good results to select a superior sperm population prior to cryopreservation, in order to produce good-quality frozen thawed semen.