Cryopreservation of margay (Leopardus wiedii) spermatozoa: effects of different extenders and frozen protocols

Abstract Sperm cryopreservation offers many benefits to wild felids conservation programs. However, the implementation of these programs is limited by the different responses of each species to the cryopreservation protocols and extenders used, requiring the formulation of species-specific protocols. For this purpose, semen samples from 6 margays (Leopardus wiedii) were submitted to 2 cryopreservation protocols: 1) manual freezing (cooling rate of – 0.33oC/min at 5oC/180 min and freezing rate with two steps – 9oC/min for 2 min and –19.1oC/min for 2 min) and 2) automatic freezing machine (cooling rate of – 0.25oC/min at 5oC/120 min and freezing rate with one step –20oC/min for 8.3 min) using 2 commercial extenders, an egg yolk-based (Test Yolk Buffer; TYB) and an egg yolk-free extender (AndroMed; MED). Post-thawed sperm quality was assessed at 3 time points (immediately after thawing and 1 and 2 h post-thawed) by sperm motility index (SMI), plasma membrane and acrosomal integrity, and mitochondrial membrane potential (MMP). Regarding SMI, TYB yielded superior results (29.4 ± 3.5 %) compared to MED (11.2 ± 2.8 %; p