Effect of Three Semen Extenders on Sperm Quality and In Vitro Fertilization Rates of Fresh and Cryopreserved Sperm Collected from Llama (Lama glama) Vas Deferens

Abstract

The advances in Assisted Reproductive Technologies (ARTs) applied in South American camelid species are still scarce. The aim of this study was to compare the effects of three semen extenders, before and after the cryopreservation of spermatozoa obtained from the vas deferens, on sperm quality parameters and in vitro fertilization rates of llama (Lama glama) oocytes. Mature fertile llama males (Lama glama; n = 6; age: 48–60 mo.; BCS: ~2.7) were included in the study. Sperm samples were collected from each male using the surgical technique of the vas deferens deviation. Then, the sperm samples were pooled and diluted with the Tris-EY, Andromed®, or BioxCell® extender in order to subsequently carry out the sperm cryopreservation process. The sperm quality assessment related to each extender was performed before and after cryopreservation with regard to sperm morphological abnormalities, acrosome integrity, sperm viability, membrane permeability, and sperm motility traits. Moreover, in vitro fertilization (IVF) procedures were carried out to evaluate the in vitro fertility of the cryopreserved sperm samples using each extender. Overall, significant differences were observed before and after cryopreservation regarding acrosome integrity, sperm viability, membrane permeability, and sperm motility traits among the extenders used, where Tris-EY and Andromed® were better than BioxCell® (p < 0.05); however, no differences were observed regarding the sperm morphological abnormalities among extenders (p > 0.05). Moreover, multiple differences were observed with regard to the velocity and linearity kinematic parameters obtained by computerized analysis before and after the cryopreservation process, irrespective of the extender used (p < 0.05). Finally, differences were observed regarding the in vitro fertilization rates among the different extender-derived samples (p < 0.05). In conclusion, the sperm quality using Tris-EY and Andromed® was better before and after cryopreservation compared to that using BioxCell®. Although the number of fertilized oocytes obtained after the IVF process between Tris-EY and Andromed® was similar, Andromed®-derived samples showed the best sperm quality results before and after cryopreservation. This indicates that the cryopreservation extender is a determining factor in significantly improving in vitro fertilization rates when using sperm samples obtained from vas deferens in llama (Lama glama) males.