Semen coagulum liquefaction, sperm activation and cryopreservation of capuchin monkey (Cebus apella) semen in coconut water solution (CWS) and TES–TRIS

The objectives of the present study were to test the effect of coconut water solution and TES–TRIS on the seminal coagulum liquefaction, sperm activation in fresh diluted semen, and on the cryopreservation of semen from capuchin monkeys (Cebus apella). Semen was collected from six males by electro-ejaculation, diluted in TES–TRIS or coconut water solution (CWS), and incubated at 35 °C until the coagulated fraction of the semen was completely liquefied. In the experiment I, after liquefaction, samples were diluted in TES–TRIS or CWS, plus 6 and 10 mM/mL of caffeine. Sperm motility and vigor were evaluated during 5 h. For experiment II, after liquefaction, semen samples were extended in TES–TRIS (3.5% glycerol in the final solution) or CWS (2.5% glycerol in the final solution), cryopreserved and stored in liquid nitrogen for 1 week. The seminal coagulum was liquefied in (mean ± SDM) 4.5 ± 1.7 and 2.8 ± 1.1 h in TES–TRIS and CWS, respectively. Sperm were motile in TES–TRIS and CWS for 5.0 ± 1.4 and 1.0 ± 0.5 h, respectively. The mean motility in this period was 38 ± 22% (TES–TRIS) and 22.0 ± 16.0 (CWS). Motility increased after caffeine addition only in samples diluted in CWS containing 6 mM (22.5 ± 16.0) or 10 mM (28.0 ± 19.0) caffeine. Post-thaw live sperm percentage was 26.2% in TES–TRIS and 13.2% in CWS. For cryopreservation of semen from C. apella TES–TRIS (3.5% glycerol) was more appropriate than CWS (2.5% glycerol). CWS + caffeine potentially increase sperm motility and may be useful in artificial insemination of fresh diluted semen.