Effect of different semen extenders for the storage of chilled sperm in Tigrina (Leopardus tigrinus).

ABSTRACT

To enhance the conservation of endangered populations, the present study aimed to evaluate whether Tigrinas (Leopardus tigrinus) sperm could be conserved under refrigeration for short periods while maintaining sufficient quality for use in assisted-reproductive techniques (i.e., cryopreservation, in vitro fertilization). For this purpose, semen samples from 15 Tigrinas individuals were submitted to conventional and functional tests after different cooling periods (4 °C; 0, 12, and 24 hours postcooling), using TCM 199 (TCM), Ham's F10 (HAM), Ham's F10 with bovine serum albumin (HBSA), and Tris-citrate egg yolk (TEYC) extenders. In a second step, semen cooled using TEYC was supplemented with reduced glutathione (GSH) at different concentrations (0, 0.5, 1.0, and 1.5 mM). TEYC yielded superior results compared with TCM, HAM, and HBSA even after 24 hours of cooling in regard to the sperm motility index (SMI-TEYC 50.2 ± 1.7%), high mitochondrial activity (TEYC 51.4 ± 1.9%), plasma membrane integrity (TEYC 53 ± 2.1%), and DNA integrity (TEYC 56.3 ± 2.9%). In regard to the concentration of thiobarbituric-acid-reactive substances (TBARS), TEYC (1900.1 ± 341.4 ng/106 spermatozoa) showed higher levels compared with the other extenders (HAM 638.7 ± 121.6 ng/106 spermatozoa; HBSA 468.7 ± 95.6 ng/106 spermatozoa; TCM 169.6 ± 31.6 ng/106 spermatozoa). However, GSH therapy had no effect. In conclusion, the TEYC extender may be useful in maintaining sperm parameters of Tigrinas for up to 24 hours at 4 °C. Furthermore, these results allow the transport of this material at a minimum quality to be further used for artificial insemination, in vitro fertilization, and the development of semen cryopreservation protocols.