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.