New protocol to separate llama sperm without enzymatic treatment using Androcoll-E™

Impact of papain on the treatment of raw diluted dromedary semen

A variety of parameters, including liquefaction and semen viscosity, affect the sperm's ability to travel and reach the egg for fertilization and conception. Given that the details behind the viscosity of the semen in male camels have not yet been fully clarified, the purpose of this study was to ascertain how the addition of papain affected the viscosity of fresh diluted camel semen. The study examined semen samples derived from camels that had distinct viscosities. Sperm motility, viability, abnormal sperm percentage, concentration, viscosity, morphometry, acrosome integrity and liquefaction were among the evaluations following 0, 5, 10, 20 or 30 min of incubation at 37°C with papain (0.004 mg/mL, 0.04 mg/mL or 0.4 mg/mL; a semen sample without papain was used as a control). A statistically significant interaction between the effects of papain concentrations and incubation time was found (F = 41.68, p = .0001). Papain concentrations (p = .0001) and incubation times (p = .0001) both had a statistically significant impact on viscosity, according to a simple main effects analysis. A lower viscosity was found (p < .05) at 0.04 mg/mL (0.1 ± 0.0) after 10 min of incubation. A simple main effects analysis showed that papain concentrations and incubation time have a statistically significant effect on sperm motility (p = .0001). At 0.04 mg/mL papain, the sperm motility % was higher (p < .05) after 10 min (64.4 ± 4.8), 20 min (68.4 ± 6.2), and 30 min incubation (72.2 ± 6.6) compared to 0, 5 min (38.3 ± 4.1 and 51.6 ± 5.0, respectively). In conclusion, the fresh diluted camel semen had the lowest viscosity properties after 10 min of incubation with 0.04 mg/mL papain, without compromising sperm motility, viability, acrosome integrity and sperm morphology.

The Effect of Cushioned Centrifugation, with and without Enzymatic Reduction of Viscosity, on the Motility Pattern and Kinematic Parameters of Dromedary Camel Bull Spermatozoa

In order to contribute to the development of semen processing procedures in camelids, the aims of the present study were to evaluate (i) the effect of 35% seminal plasma incubation on dromedary camel epididymal sperm motility and kinematic parameters, (ii) the effects of centrifugation, with cushion fluid and enzymatic reduction of viscosity (Papain + E64) during ejaculate processing, on the motility and kinematic parameters of dromedary camel ejaculates. The incubation with seminal plasma significantly reduced the percentage of progressively motile spermatozoa as well as the proportion of medium progressive spermatozoa whilst increasing the percentage of non-progressive spermatozoa. The centrifugation procedure improved the sperms' kinematic parameters, and the highest values were observed for samples centrifugated with cushion fluid. The samples treated with Papain + E64 showed a significant increase in both total and medium progressive spermatozoa, along with a reduction of non-progressive spermatozoa (p < 0.05). The results of this investigation show that a simple, cheap, and effective procedure, such as cushioned centrifugation, could improve the motility patterns of dromedary camel spermatozoa; in combination with enzymatic reduction of viscosity, this method leads to the best results in terms of recovery rates and sperms' kinematic parameters.

Cryopreservation modifies the distribution of the prostate-derived lectin SL15 on the llama (Lama glama) sperm

Lectin-like molecules play a key role in mammalian sperm functionality. These multifunctional proteins have been proven to be involved in sperm capacitation, sperm motility, and viability, formation of the oviductal sperm reservoir, and in sperm-oocyte interaction. In a previous study, we reported the presence of a novel seminal plasma lectin, sperm lectin 15 kDa (SL15), adsorbed to the llama sperm. In order to gain knowledge in the understanding of SL15 and its functions, the aims of this study were to (a) elucidate the presence and localization of SL15 in the llama male reproductive tract and sperm, and (b) determine whether the sperm cryopreservation process of cooling and freeze-thawing affects the SL15 levels and distribution on llama sperm. We found that SL15 protein was expressed along the male reproductive system: testis, epididymis, prostate, and bulbourethral glands, being the prostate the main site of SL15 secretion. SL15 was localized on the sperm head, following different localization patterns. In order to understand if sperm cryopreservation induces modifications in the SL15 adsorption pattern, immunocytochemistry and flow cytometry analysis were carried out on fresh, 24 h cooled, and frozen-thawed sperm. Both cooled and frozen sperm showed particular SL15 patterns, that were not observed in the freshly ejaculated, indicating loss of SL15. Flow cytometry analysis also exhibited a decrease of SL15 in the cooled sperm (P < 0.05), whereas a tendency to decrease was found in frozen-thawed sperm (P < 0.1) when compared with freshly ejaculated sperm. This study extends the knowledge about the SL15 in the llama male physiology and provides evidence that cryopreservation-related techniques disrupt SL15 adsorption to the sperm membrane, possibly affecting sperm functionality and fertility.

Use of commercial extenders, with and without the addition of egg yolk, for cooling llama semen

The objective of this study was to evaluate the effect of two commercial extenders, AndroMed® (AM) and Androstar® Plus (AS) both with and without the addition of egg-yolk (EY), for cooling llama semen. A total of sixteen ejaculates were collected from four males. Each ejaculate was divided into four aliquots and diluted with: AM, AM with 20 % EY (AM-EY), AS and AS with 20 % EY (AS-EY) and then cooled to 5 °C in an Equitainer®. Evaluations were carried out in raw semen, after dilution (0 h) and after 24 and 48 h of cooling. Data were analysed using either Friedman or ANOVA. Although total motility decreased in all cooled samples compared to the corresponding 0 h (P < 0.05), the highest percentages were observed in AM-EY being significantly higher than all other cooled samples after 24 h and higher than AS and AS-EY after 48 h. No significant differences were observed in the percentages of live acrosome-intact sperm between extenders at all times tested. A significant decrease in the percentage of sperm membrane osmotic function was observed in samples cooled with AS and AS-EY after 24 and 48 h vs. raw semen and in AM 48 h vs. raw semen. Finally, a significant increase in the percentage of sperm with abnormal tails was observed in the samples cooled with AS and AS-EY. Of all the extenders used, AndroMed® could be considered an option for cooling llama semen and the addition of EY to this extender improves its effectiveness. DATA AVAILABILITY: The data that support the findings of this study are available from the corresponding author upon reasonable request.

Cooled storage of semen from livestock animals (Part II): Camelids, goats, and sheep

This review is part of the Festschrift in honor of Dr. Duane Garner and provides an overview of current techniques in cooled storage of semen from livestock animals such as camelids, goats, and sheep. Facing worldwide environmental changes and a trend towards more conscious and healthy eating behaviors, the development of a stable animal breeding industry is a significant challenge for the near future. In the present review, factors influencing semen handling in camelids, goats and sheep are described and relevant methods as well as current trends to improve liquid-storage of cooled semen are discussed, including extenders, additives, cooling rates, and storage temperatures. The species-specific physiology and resulting challenges are taken into consideration. While the main problem for camelid semen processing is the relatively greater viscosity as compared with that of some other animals, the deciding factor for successful artificial insemination (AI) in goats and sheep is the site (i.e., cervical or vaginal) of semen placement in the reproductive tract. Due to the type of cervical anatomy, the penetration of the cervix when using AI instruments is rather difficult. Furthermore, the seminal plasma of small ruminants affects the interaction with milk-based extenders and egg yolk which results in species-specific regimens for cooled liquid-preservation. Comparing all three species, the greatest pregnancy rates were obtained by AI with goat semen after cooled liquid-storage for several days.

Use of Androcoll-ETM to Separate Frozen-Thawed Llama Sperm From Seminal Plasma and Diluent

It is not easy to separate frozen-thawed South American camelid sperm from seminal plasma (SP) and diluents to be used for in vitro embryo production. The objective of this study was to evaluate Androcoll-E™ (AE) efficiency to separate llama sperm from SP and freezing extender in frozen-thawed semen. A total of 22 ejaculates from five Lama glama males were collected using electroejaculation. After performing semen analysis (sperm motility, concentration, viability, membrane function, and acrosome integrity), samples were cryopreserved with a diluent containing lactose, ethylenediaminetetraacetic acid (EDTA), egg yolk, and 7% dimethylformamide. After thawing, samples were divided in aliquots, one of which was used as a control and the others processed by AE. Experiment 1 (12 ejaculates): 100 μl of frozen-thawed semen was placed on top of 1,000 μl AE column and centrifuged at 800 g for 10 min. Experiment 2 (10 ejaculates): two samples of 100 μl of frozen-thawed semen were placed on two columns of 500 μl AE each, and both were centrifuged at 800 g for 10 and 20 min, respectively. Pellets were resuspended in Tyrode's albumin lactate pyruvate (TALP) medium, and sperm parameters were evaluated. A significant decrease in all sperm parameters was observed in thawed samples compared to raw semen. AE allowed the separation of frozen-thawed sperm from SP and freezing extender independently from the height of the column used and time of centrifugation assayed. Although no significant differences were found between AE columns, higher sperm recovery was observed with 500 μl of AE coupled with 20 min of centrifugation. Despite the significant decrease observed in sperm motility in AE samples, no changes in sperm viability, membrane function, and acrosome integrity were observed when comparing control thawed semen with the sperm recovered after AE (p > 0.05). The use of AE columns, either 500 or 1,000 μl, allows the separation of frozen-thawed llama sperm from SP and freezing extender, preserving the viability, membrane function, and acrosome integrity. Of the protocols studied, 800 g centrifugation during 20 min using a 500 μl column of AE would be the method of choice to process frozen-thawed llama semen destined for reproductive biotechnologies.