Sperm-bound antisperm antibodies are associated with poor cryosurvival of stallion spermatozoa

• Published in: Theriogenology 2021-09, Vol.172, p.261-267
• Main Authors: Ferrer, M.S., Canisso, I.F., Podico, G., Ellerbrock, R.E., Hurley, D.J., Palomares, R.
• Format: Article
• Language: English
• Subjects: Cryopreservation; Equine; Freezing; Horse; Semen
• ISSN: 0093-691X; 1879-3231
• DOI: 10.1016/j.theriogenology.2021.07.008

Different stallions exhibit a high level of variation in the ability of their sperm to survive cryopreservation. A large fraction of stallions show poor post-thaw sperm motility, and their semen is not suitable for commercial freezing. In this study, we hypothesized that the presence of sperm-bound antisperm antibodies (ASAs) was associated with poor cryosurvival of stallion sperm. Our objective was to assess the level of ASA binding to stallion sperm, and determine if it was associated with good or poor sperm cryosurvival. In Experiment 1, cooled shipped semen from 27 stallions was frozen using three commercial semen extenders. Sperm motility, membrane integrity, acrosome integrity and apoptosis were evaluated before and after freezing for each aliquot. In addition, the percentage of ASA-bound sperm was evaluated post-thaw. In Experiment 2, semen from 22 stallions was frozen immediately after collection a single formulation of semen extender. Sperm motility and ASA binding were evaluated post-thaw. The results of both experiments showed similar findings. The frequency of ASA-positive samples was higher among stallions with poor sperm cryosurvival (Exp. 1 and 2 = 6/11, 54.5%) than for good sperm cryosurvival (Exp. 1 = 0/16, 0%; Exp. 2 = 1/11, 9.1%). The percentage of IgG- and IgA-bound sperm was also higher in stallions with poor sperm cryosurvival in both experiments (P