Effect of transportation temperature on the quality of cauda epididymal spermatozoa of ram

The Influence of Three Commercial Soy Lecithin-Based Semen Extenders and Two Spermatozoa Concentrations on the Quality of Pre-Freeze and Post-Thaw Ram Epididymal Spermatozoa

There are limited studies on the factors affecting the success of ram epididymal spermatozoa (REPS) cryopreservation. On this note, the current study assessed the influence of three commercial soy lecithin-based semen extenders, AndroMed® (AND), BioXcell® (BIO), and OviXcell® (OVI), and two concentrations (400 × 106 vs. 200 × 106 spermatozoa/mL) on the pre-freeze and post-thaw quality of REPS. The REPS were retrieved from nine adult rams' testes and diluted with each of the three extenders to both concentrations. Straws were frozen manually. Standard motility (SMP) and kinematic parameters (KPs) were assessed via a CASA, while spermatozoa viability, morphology, and acrosomal integrity were assessed via the Kovács-Foote staining technique. The concentration did not significantly affect the pre-freeze and post-thaw SMP and KPs of REPS. BIO and OVI had significantly higher pre-freeze and post-thaw BCFs, post-thaw VAP, and the percentage of all intact heads than AND. In contrast, AND had a significantly lower percentage of REPS with tail defects than BIO and OVI. The 400 × 106 spermatozoa/mL concentration resulted in a significantly higher percentage of all intact heads than the 200 × 106 spermatozoa/mL concentration. Freezing significantly increased tail defects and decreased the percentage of REPS with distal cytoplasmic droplets. The cryopreservation of REPS at the 400 × 106 spermatozoa/mL concentration is recommended. All three extenders must be optimized to preserve the viability, membrane integrity, and better normal morphology of REPS; the reason for increased tail abnormality after the freezing/thawing process needs to be studied.

Postmortem Collection of Gametes for the Conservation of Endangered Mammals: A Review of the Current State-of-the-Art

The collection of gametes from recently deceased domestic and wildlife mammals has been well documented in the literature. Through the utilization of gametes recovered postmortem, scientists have successfully produced embryos in 10 different wildlife species, while in 2 of those, offspring have also been born. Thus, the collection of gametes from recently deceased animals represents a valuable opportunity to increase genetic resource banks, obviating the requirement for invasive procedures. Despite the development of several protocols for gamete collection, the refinement of these techniques and the establishment of species-specific protocols are still required, taking into account both the limitations and the opportunities. In the case of wildlife, the optimization of such protocols is impeded by the scarcity of available animals, many of which have a high genetic value that must be protected rather than utilized for research purposes. Therefore, optimizing protocols for wildlife species by using domestic species as a model is crucial. In this review, we focused on the current advancements in the collection, preservation, and utilization of gametes, postmortem, in selected species belonging to Equidae, Bovidae, and Felidae, both domestic and wildlife.

Fluorescence Microscopy and Flow-Cytometry Assessment of Substructures in European Red Deer Epididymal Spermatozoa after Cryopreservation

Thawed spermatozoa, sampled post mortem from the fresh epididymides of European red deer and epididymides stored for up to 12 h at 2–4 °C, were evaluated by fluorescence microscopy (FM) and flow cytometry (FC). The sperm samples were extended and cryopreserved. The sperm motility (CASA), sperm viability (SYBR+/PI-), acrosome integrity, mitochondrial activity, apoptotic changes, and chromatin stability were assessed. Sperm were analyzed by FM before cryopreservation, and by FM and FC after thawing. Epididymal storage time (for 12 h) had no significant effect (p > 0.05) on the examined variables before cryopreservation. After thawing, the storage variants differed (p ˂ 0.05) in the percentage of apoptotic sperm (FM and FC) and DNA integrity (FC). The results of FM and FC differed (p ˂ 0.05) in all the analyzed parameters, excluding SYBR+/PI. Significant correlations (p ˂ 0.01) were observed between the sperm viability, acrosome integrity, and the percentage of non-apoptotic spermatozoa, regardless of the applied technique. In FM, the above parameters were also significantly correlated with mitochondrial activity. The study demonstrated that European red deer spermatozoa stored in the epididymides at 2–4 °C for 12 h can be used for cryopreservation. Both techniques were equally reliable, but FM was better suited for evaluating mitochondrial activity whereas FC was more useful in the evaluation of DNA fragmentation.

Semen collection by urethral catheterization and electro-ejaculation with different voltages, and the effect of holding temperature and cooling rate before cryopreservation on semen quality in the Japanese macaque (Macaca fuscata)

In the Japanese macaque, semen has been collected by electro-ejaculation (EE), using the higher voltage stimuli compared to other species including genus Macaca. Semen coagulate immediately after ejaculation, which makes difficult to produce high-quality semen for artificial insemination. Recently, semen collection using urethral catheterization (UC) has been reported in carnivore and this technique may allow semen collection without coagulation in a less invasive manner. Further, the temporal preservation temperature and cooling rate of semen during cryopreservation affect post thawing sperm quality. In this study, to improve semen quality and quantity, as well as the animal welfare, semen collection was performed by EE with high (5-15 V) or low (3-6 V) voltage, UC and a combination of the two (EE-UC). It has been suggested that a high voltage is necessary for semen collection, but 10 V stimulation was effective enough and 15 V is for additional sperm collection. Also, liquid semen was collected by EE-UC and this could increase the total number of sperm. Further, to improve the post thawing sperm motility, semen was kept at four temperatures (4, 15, 25 and 37˚C) for 60 min, and processed with two cooling procedures (slow cooling before second dilution and fast cooling after second dilution). Holding semen at 25˚C and fast cooling after the second dilution maintained progressive motile sperm rate. The present results will contribute to the improvement of semen collection and animal welfare of Japanese macaques.

Effect of storage time on the quality of cauda epididymal spermatozoa of West African dwarf (WAD) rams

The objectives of the study were to develop a protocol for preserving Western African Dwarf (WAD) ram cauda epididymal semen that could be applied in preserving and storing the semen of endangered species/genetically valuable animals in case of death and to study the morphometric characteristic of epididymides after refrigerated storage. Thirty testes-epididymides were collected immediately after slaughter from mature WAD rams and transported in ice chest at (4.5-6 °C) to the laboratory. The samples were either processed immediately or stored in a refrigerator at 5 °C for 6, 12, 24, 48 h. The results indicate that the semen motility decreased (P <  0.05) when compared to the control [87.5 ± 2.1% (0 h), to 85.0 ± 1.8% (6 h), 73.3 ± 3.6% (12 h), 53.3 ± 2.5% (24 h) and 50.0 ± 2.9% (48 h)]. The sperm concentration also decreased (P <  0.05) as duration of storage increased (0 h) 157.5 ± 8.2, (6 h) 152.3 ± 5.8, (12 h) 125.3 ± 4.4, (24 h) 106.2 ± 2.9, (48 h) 98.5 ± 3.5. Semen viability decreased as duration of storage increased from the 0 h to 48 h [(P <  0.05; 84.0 ± 1.4%, 82.8 ± 2.2%, 77.3 ± 1.7%, 69.8 ± 1.5%, and 66.5 ± 1.2%, respectively]. Furthermore, there was a decrease (P <  0.05) in percentage of intact acrosome as duration of storage increased [(0 h) 90.7 ± 1.0%; (6 h) 89.3 ± 2.0%; (12 h) 85.5 ± 1.6%; (24 h) 70.0 ± 2.4%; and (48 h) 73.3 ± 2.1%]. The results from this study indicate that epididymal semen of WAD rams recovered and preserved at 5 °C for 48 h may be used for artificial insemination.

Viability of ovine spermatozoa collected from epididymides stored at 18°-25°C for 48 hours post mortem

ABSTRACT The objectives of this study were to verify the time during which viable ovine spermatozoa could be recovered from the cauda epididymis kept at ambient temperature (18-25°C). Sperm collected in an artificial vagina (AV) were used as control. Spermatozoa samples were collected with an AV and from epididymis at 0 (G0), 6 (G6), 12 (G12), 24 (G24), and 48 (G48) hours post mortem. Total motility (TM), progressive motility (PM), hypo-osmotic membrane integrity test (HOST) and morphological changes were assessed. TM decreased (P<0.05) from 24 hours post mortem (70.0±1.9%) compared to AV (86.4±1.0%). PM decreased (P<0.05) from 12 hours after death (31.3±4.0%) compared to AV group (73.2±1.4%). The percentage of viable cells in HOST decreased (P<0.05) in the G48 (60.0±8.9%). Spermatozoa recovery was lower (P<0.05) 48 hours after death (2064.2±230.7 x 106 spermatozoa) compared to G0(2623.6±288.4 x 106 spermatozoa). In conclusion, under the conditions of this study, it would be possible to use epididymal spermatozoa recovered up to 24 hours after death for artificial insemination or in vitro fertilization; however, fertility trials are necessary to prove this hypothesis.

Evaluation of sperm recovered after slaughter from cauda epididymides of red Sokoto bucks

AIM

Viable spermatozoa could be recovered from the cauda epididymides for the purpose of preservation of genetic material of male animals with desirable traits and for use in reproductive biotechnology. The aim of this study was to determine the effect of storage time on testicular and epididymal biometry, sperm reserves and epididymal sperm characteristics of red Sokoto bucks post mortem.

MATERIALS AND METHODS

Testes-epididymides were collected immediately after slaughter of mature red Sokoto bucks and transported in ice chest to the laboratory. The samples were either processed immediately or stored at 5°C in refrigerator for 24, 48 h and then processed. The testes and epididymides were measured and weighed. Sperm motility, concentration, livability, morphology, intact acrosome, and sperm reserves from different treatment groups including control were evaluated and means (±standard error of mean) were recorded.

RESULTS

There was no significant difference (p>0.05) in the testicular and epididymal dimensions determined between the means of the groups. Percent sperm motility and viability decreased significantly (p<0.05) after 24 h from 69.00±0.46 and 71.27±0.50% to 50.60±0.48 and 60.47±0.70% at 48 h, respectively. Significant decreases (p<0.05) in epididymal sperm concentration and intact acrosome from 2.86±0.08 and 92.87±0.39 at 0 to 24 h of storage, respectively, were observed.

CONCLUSION

The results of this study suggest that spermatozoa recovered from the epididymides of red Sokoto bucks were viable after storage for up to 48 h. Furthermore, this finding offers some hope that epididymal sperm recovered post-mortem can be used in assisted reproductive technologies.

Effect of washing on the post-thaw quality of cryopreserved ram epididymal spermatozoa

Aim:

The aim of the study was to evaluate the effect of washing on the post-thaw quality of ram cauda epididymal spermatozoa (P1: Unwashed, P2: Washed).

Materials and Methods:

Fresh testicles of adult healthy slaughtered rams were collected and transported to the laboratory in an ice chest, where they were weighed, and cauda epididymides were separated. These cauda epididymides were used for recovery of spermatozoa in tris-citric acid fructose buffer by incision method. Spermatozoa samples showing ≥70% progressive motility were pooled and processed further. The mean values (±standard error) of various parameters such as the percentage of sperm motility, live sperm, intact acrosome, and hypo-osmotic swelling test (HOST) reacted spermatozoa were recorded.

Results:

In this experiment, the percent sperm motility, live spermatozoa, and intact acrosome both at pre-freeze and post-thaw were higher (p>0.05) in P1 than P2. However, the post-thaw percent HOST reacted spermatozoa was slightly higher (p>0.05) for P2 than P1.

Conclusion:

Washing of cauda epididymal spermatozoa has no significant adverse effect on the quality during cryopreservation. Therefore, this processing method can be applied wherever necessary before the extension of the recovered spermatozoa sample in different ram extenders.

Variations of motility and survival with storage time at 4°C of epididymal spermatozoa Ouled-Djellal breed rams in Eastern Algeria

Aim:

The aim of this study was to evaluate some reproduction performances in Ouled-Djellal rams.

Materials and Methods:

This study involved genital organs removed after slaughter from 54 rams at the municipal slaughterhouse of Batna (East Algeria).

Results:

The measurements of survival and mobility of epididymal sperm followed at 0, 24, 48 and 72 h after collection, revealed significant (p<0.05) to highly significant differences (p>0.001) according to time. Thus, concerning the sperm motility the values were 91.00±2.40%, 89.20±2.40%, 77.00±6.20% and 62.60±1.20% at 0, 24, 48 and 72 h, respectively. Indeed, in live sperm, the viability rates were 82.15±1.48%, 77.67±1.74%, 66.56±1.95% and 52.30±1.46% at 0, 24, 48 and 72 h, respectively.

Conclusion:

This study revealed that epididymal spermatozoa stored at 04°C for 72 h kept their mobility and vitality at nearly a half of their the original parameters.

Effects of post-mortem storage conditions of bovine epididymides on sperm characteristics: investigating a tool for preservation of sperm from endangered species

The aim of this study was to establish and validate a reliable and efficient protocol for the recovery and cryopreservation of epididymal spermatozoa used for in vitro fertilization, using bulls of two different age classes. Testicles from 26 (37-51 weeks old, group 1) and 19 (52-115 weeks old, group 2) Danish Holstein bulls were collected after slaughter and stored at 5°C. After 0, 24 or 48 h, epididymides were isolated and spermatozoa collected. Assessments included spermatozoal motility, viability and morphology before and after cryopreservation and in vitro embryo production. Results showed that live spermatozoa can be collected from epididymides of bulls after their death. Storage of the testicles at 5°C for 24 h followed by cryopreservation of recovered epididymal spermatozoa resulted in 21% (group 1) and 31% (group 2) blastocysts produced in vitro. These results illustrate that epididymal spermatozoa recovered from testicles kept in specific conditions can be used to preserve genetic material from endangered and threatened species or populations in nature as well as in domestic and zoo animals.

CRYOPRESERVATION OF ONAGER (EQUUS HEMIONUS ONAGER) EPIDIDYMAL SPERMATOZOA

Genetic diversity is a primary component of adaptive evolution, and its loss or reduction can decrease the long-term survival probability of populations. Utilization of cryopreserved semen may be considered a perfect tool to improve genetic diversity, reduce inbreeding, and avoid animal translocation for breeding. The present study aimed at finding a reliable epididymal sperm freezing protocol for the critically endangered onager (Equus hemionus onager). Six testicles from three animals were processed postmortem. The effects of two transportation temperatures (22°C and 4°C; testicles submerged in saline), two cryopreservation techniques (conventional liquid nitrogen vapor freezing in straws and directional freezing in 8-ml HollowTubes(TM)), and two postthaw incubation temperatures (22°C and 37°C; evaluated after 0.5, 1, 2, and 3 hr) were tested in a 2×2×2 experimental design. Sperm samples were evaluated for motility, viability, acrosome integrity, and sperm morphology. The resulting optimal freezing protocol includes transportation of testicles at 4°C, cryopreservation by directional freezing, and, if needed, postthaw incubation at 22°C. With this combination of transportation temperature and cryopreservation technique, the authors obtained the following postthaw values normalized to prefreezing values: 60.3±8.8% motility, 60.7±13.3% viability, 75.3±9.5% acrosome integrity, and 94.7±2.9% normal morphology (excluding defects due to the epididymal origin of the sperm). After incubation at 22°C, motility values for the above combination were 40±5.7%, 30.3±5.2%, 28.3±4.4%, and 16.7±4.4% for 0.5, 1, 2, and 3 hr, respectively. In conclusion, with this protocol, good quality semen can be stored for future use in artificial inseminations when and where needed.

Effect of testicle postmortem storage on goat frozen-thawed epididymal sperm quality as a tool to improve genebanking in local breeds

The interest to develop assisted reproductive technologies and cryobanking for farm animal genetic resource conservation has recently increased. However, cryopreservation for ex-situ management of genetic diversity sometimes is not routinely feasible, owing to the lack of facilities (AI centres, laboratories) and expertise near the local breed farming area. In these cases, epididymal sperm obtained from slaughtered or castrated animals, associated with the possibility of managing rather long periods between animal death, sperm recovery and freezing, would increase the opportunities to create semen storages. This investigation addresses the pre-freeze/post-thaw quality of goat epididymal sperm as a function of testicle storage temperature (environment or +5°C) and time elapsed between animal's death and sperm recovery (0, 24, 48, 72 h) to establish the optimal protocols for the recovery and cryopreservation of epididymal sperm in this species. Testicles of 50 mature bucks collected at the abattoir were divided in two groups: half of the testicles (n=50) were transported to the laboratory at environment temperature (E), whereas the remaining half (n=50) at a refrigeration temperature (R) of +5°C. In the two groups (E) and (R), one testicle from each pair was processed after slaughter forming the time 0 groups (0E and 0R). The contralateral testicle was processed after 24, 48 or 72 h of storage, at the corresponding temperature. Sperm motility and kinetic parameters, viability and morphology were assessed in pre-freeze and post-thaw samples. Until 48 h postmortem, both E and R temperatures are able to maintain good pre-freeze epididymal sperm quality. After 48 h postmortem, R temperature is fundamental to reduce epididymal sperm quality decay in pre-freeze samples. Moreover, testicle refrigeration also has a positive impact on post-thaw samples, allowing a lower decline through time considering total motility, kinetics parameters, sperm viability and sperm abnormalities. Therefore, when sperm cryopreservation is not immediately practicable, goat testicles should be transported and stored at 5°C up to a maximum of 48 h postmortem to ensure an acceptable sperm quality.

Cryopreservation of canine epididymal sperm using ACP-106c and TRIS

The objective was to cryopreserve sperm recovered from the canine epididymal cauda immediately after an orchiectomy. The sperm was stored for 12h at 4 °C using ACP-106c and TRIS as extenders. Sixty adult male dogs were used. The testis-epididymis complex (TEC) was removed, immersed in 0.9% saline and transported to the laboratory. The 60 TEC were divided into groups according to the 4 °C cooling time (0 h or 12 h) and according to the extender used for sperm recovery (ACP-106c or TRIS), forming 4 experimental groups: G0h-ACP, G12h-ACP, G0h-TRIS and G12h-TRIS. The sperm were recovered from the epididymal cauda using the retrograde flow technique. Next, 1.0 mL of ACP-106c or 1.0 mL of TRIS (preheated to 37 °C for 5 min) was added to the sperm of each epididymis. One week later, the sperm was thawed at 37 °C for 1 min, and its morphology, functionality and total and progressive sperm motilities were analyzed. Other parameters were obtained by Computer Assisted Semen Analysis (CASA). The data were submitted to multivariate analysis of variance (MANOVA) (P<0.05). The total motility values were 52.17 ± 1.78 and 49.8 ± 1.93 for groups G0h-ACP and G12h-ACP and 50.7 ± 2.06 and 43.90 ± 2.51 for groups G0h-TRIS and G12h-TRIS, respectively. A decrease in total sperm motility was observed after 12h of cooling for both extenders (P<0.05). ACP-106c can be used as an extender for freezing canine epididymal sperm, and the freezing procedure must be performed immediately after sperm recovery.

Refrigeração do epidídimo canino a 4ºC e recuperação dos espermatozoides epididimários utilizando ACP-106c

Objetivou-se avaliar a qualidade dos espermatozoides recuperados da cauda do epidídimo após a refrigeração do complexo testículo-epidídimo (CTE) de cães usando o diluidor ACP-106c. Foram utilizados 60 cães machos adultos, com peso de 10-20 kg. Após a eutanásia, removeu-se o CTE que foi imerso em solução fisiológica 0,9% e transportado em caixa térmica ao laboratório a 30ºC. Para a refrigeração e recuperação dos espermatozoides epididimários, os 60 pares do CTE foram divididos em 4 grupos, de acordo com o tempo de refrigeração do CTE e posterior recuperação espermática: G0h, G6h, G12h e G18h, em que cada par do CTE permaneceu por zero, seis, doze ou dezoito horas a 4ºC, respectivamente. A recuperação dos espermatozoides da cauda do epidídimo foi realizada pela técnica de flutuação utilizando-se o diluidor ACP-106c ou Tris. Para cada epidídimo foi adicionado 1,0 mL de um dos dois diluidores, pré-aquecidos a 37ºC por 5 minutos. Em seguida foram centrifugados a 800g/5 minutos para remoção dos resíduos celulares. Avaliou-se a morfologia, funcionalidade e motilidade espermática total e progressiva, além de parâmetros obtidos pelo CASA. Os dados foram submetidos à ANOVA seguido do teste de Turkey (P < 0,05). Em todos os parâmetros avaliados, não houve diferença entre os diluidores testados (P>0,05). Os valores de motilidade total nos grupos G0h, G6h, G12h, e G18h para o ACP-106c foram 84,4±7,7; 81,6±11,6; 88,3±6,5 e 69,5±16,9, respectivamente, e para o Tris 85,2±8,7; 77,4±14,3; 79,0±17,8 e 65,4±17,9, respectivamente. Um decréscimo na qualidade espermática foi observado após 18 horas de refrigeração em ambos os diluidores. Dessa forma pode-se concluir que o ACP-106c pode ser utilizado para recuperar os espermatozoides epididimários refrigerados e podem ser viáveis por até 12h de refrigeração.