Factors impacting equine sperm recovery rate and quality following cushioned centrifugation

• Published in: Theriogenology Vol. 70; no. 4; pp. 704 - 714
• Main Authors: Waite, J.A., Love, C.C., Brinsko, S.P., Teague, S.R., Salazar, J.L., Mancill, S.S., Varner, D.D.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.09.2008; [Oxford]: Butterworth-Heinemann; [New York]: Elsevier Science
• Subjects: Animals; Centrifugation; Centrifugation - methods; Centrifugation - veterinary; chemical treatment; collectors; Cryopreservation - methods; Cryopreservation - veterinary; Cushion; cushioned centrifugation; equipment design; germplasm conservation; Horses - physiology; iodixanol; Male; male reproductive system; mechanical properties; methodology; optical properties; processing technology; protective effect; Semen; semen extenders; Semen Preservation - methods; Semen Preservation - veterinary; separation; Specimen Handling - methods; Specimen Handling - veterinary; Sperm; sperm motility; Sperm Motility - physiology; spermatozoa; Spermatozoa - cytology; Spermatozoa - physiology; Stallion; stallions; veterinary equipment; Cushion; Semen; Sperm; Centrifugation; Stallion
• ISSN: 0093-691X; 1879-3231
• DOI: 10.1016/j.theriogenology.2008.04.047

Two experiments were conducted to investigate modifications in cushioned centrifugation of stallion semen. Specifically, the effects of tube type, centrifugation medium, cushion type, and centrifugation force on post-centrifugation sperm recovery rate and quality were evaluated. In Experiment 1, sperm recovery rate was higher (P<0.05) in conventional plastic conical-bottom tubes (103%) than in newly developed glass nipple-bottom tubes (96%) following cushioned centrifugation; however, several measures of semen quality (i.e., % total motility [MOT], % progressive motility [PMOT], curvilinear velocity, and average-path velocity) yielded higher values following centrifugation in nipple-bottom tubes (P<0.05). Sperm recovery rate following cushioned centrifugation was similar between semen previously diluted in optically clear centrifugation extender (100%) and semen diluted in opaque centrifugation extender (100%); however, MOT and PMOT were higher in semen subjected to cushioned centrifugation in opaque extender (P<0.05). An extender by tube-type interaction was not detected for recovery rate or post-centrifugation semen quality. In Experiment 2, sperm recovery rate following cushioned centrifugation in nipple-bottom tubes was similar when forces of 400×g or 600×g were applied (90 and 90%, respectively; P>0.05), and no resulting differences in semen quality were detected between these treatment groups (P>0.05). The type of iodixanol cushion medium used (i.e., OptiPrep™, Eqcellsire® Component B, or Cushion Fluid™) did not impact post-centrifugation semen quality, based on the laboratory values measured (P>0.05). In conclusion, cushioned centrifugation of stallion semen in either conical-bottom or nipple-bottom tubes yielded a high sperm harvest, while maintaining sperm function. An optically opaque extender, commonly used in the equine breeding industry, can be used to achieve this goal.