Comparison between two glycerol concentrations to cryopreservation of semen of mountain lions (Puma concolor)

The development of biotechnologies of reproduction is an important tool for the conservation of wild animals threatened with extinction. Assisted reproduction procedures in mountain lions, however, are scarce, especially those related to sperm cryopreservation. In this context, this study aimed to evaluate the freezing capacity of semen from adult mountain lions in captivity through the comparison of two concentrations of glycerol in the freezing media. Five adult male mountain lions were used, held at the Rehabilitation Center for Wild Animals of Mato Grosso do Sul (CRAS/MS). Samples were collected by electroejaculation and evaluated for physical appearance, volume, sperm progressive status, sperm motility, sperm concentration and sperm motility index. Each ejaculate was spliced into two aliquots and diluted in Tris-citrate-half egg yolk, at final concentrations of 5 and 7.5% glycerol, cooled at a rate of -0.55 degrees C/min and frozen at a rate of -5.8 degrees C/min. Once thawed, the samples were re-evaluated and tested for thermoresistance and hypoosmotic swelling. The suggested protocol for cryopreservation and thawing of semen is efficient in both glycerol concentrations tested, with no difference (p>0.05) between them.