Improvement of stored turkey semen quality as a result of He-Ne laser irradiation

Two experiments were carried out to evaluate the effects of He-Ne laser irradiation at various energy doses on the quality of stored turkey semen. Four semen pools were used in Experiment 1. Each pool was divided into 10 aliquots, nine of which were irradiated with energy doses ranging from 0.144 to 10.8 J/cm2 while the tenth one was not irradiated (control). Each sample was evaluated for motility immediately after irradiation, 24 and 48 h later. Energy doses ranging from 3.24 to 5.4 J/cm2 had higher (P <0.01) sperm motility index (SMI) value compared to the control and samples irradiated with lower and higher laser doses. The energy dose of 3.96 J/cm2 was selected for Experiment 2 to obtain further insight on its effects on turkey sperm preservation for up to 60 h. Each pool of four semen was divided into two aliquots: one represented the control and the other one was irradiated with He-Ne laser at an energy dose of 3.96 J/cm2. Each sample was evaluated for motility and viability immediately after irradiation and then at 12 h intervals up to 60 h. The cell energy charge was also measured by HPLC. Exposure to 3.96 J/cm2 increased the SMI and viability of turkey semen stored for 60 h compared to the control (P <0.05). The cell energy charge of irradiated samples was 200% higher than in the control. Laser irradiation increased the longevity of stored turkey spermatozoa, and might be a useful technique to enhance semen quality in long-term storage.     

Efficiency of short-term storage of equine semen in a simple-design cooling system

Five experiments tested the efficiency of a simple, low-cost system (CP) for cooling and storing equine semen at 2.0 degrees C for 24 h and 48 h. Pantaneiro stallions of known fertility were used. Semen quality was evaluated for progressive motility (PM), plasma membrane integrity (PMI), and pregnancy rate. Experiment 1 showed that PM and PMI were similar between CP and the control (Equitainer) in cooled semen. In Experiment 2, the influence was evaluated of combinations (four treatments) of two volumes (50/100 ml) and two sperm concentrations (500/750x10(6)) on sperm quality of semen cooled and preserved by CP (cooling system replaced at 24 h). While PM decreased gradually from before cooling to 24 h and 48 h, PMI decreased only at the least and greatest sperm volume and concentrations. Storage time did not affect PMI. Results from Experiment 3 showed that CP maintained semen PM>or=30% in all samples 24 h after cooling and decreased to about 70% 42 h after cooling. Results from Experiments 4 and 5 confirmed semen quality after cooling and storage (24 h and 48 h, respectively), achieving a 69% pregnancy rate in the first estrous cycle when insemination occurred. Thus, the CP system is satisfactory for cooling and preserving equine semen for up to 48 h.     

Sperm viability of canine and caprine semen samples preserved in a dry shipper

This study assessed the efficacy of a dry shipper to preserve canine and caprine semen samples. After equilibration, semen straws from six Majorera bucks and five dogs were frozen and stored in liquid nitrogen (LN). Thirty days after freezing, half of the frozen straws were transferred from LN to a dry shipper (DS). Then, thawing was performed at 1, 2, 3, 5 and 7 days and the percentages of motile spermatozoa, acrosome intact spermatozoa and abnormal spermatozoa were determined. The sperm motility (total and progressive) of canine semen samples preserved with DS was quite similar to those preserved in LN, and no significant differences were observed throughout the experimental period. In addition, no differences were observed in the number of abnormal spermatozoa (range: 13.2-19.0%) or intact acrosome (range 91.3-95%) between both storage protocols. Buck semen samples showed equivalent levels of progressive motility (between 50% and 60%) and intact acrosome membrane (around 70%) during the first 3 days of storage in both procedures; however, from the fifth day of storage onwards, a notable decrease in semen quality was observed in the samples preserved in DS, showing a dramatic fall in the semen viability after 7 days of preservation (12.3% and 36.8%, progressive fast spermatozoa and acrosome integrity, respectively). In dog samples, the present study confirmed that seminal quality did not show modifications for the preservation period (7 days), confirming the efficacy of the dry shipper to preserve frozen samples for a short time. However, under the circumstances reported in this study, the sperm quality of buck samples preserved in the dry shipper only held during the first 3 days of storage, and therefore, its practical application could be more limited.     

Use of single-layer centrifugation with Androcoll-C to enhance sperm quality in frozen-thawed dog semen

The aim of this study was to investigate whether single-layer centrifugation (SLC) with Androcoll-C could select good quality spermatozoa, including those with specific motility patterns, from doses of frozen dog semen. Semen from five dogs was collected and cryopreserved following a standard protocol. After thawing, the semen samples were divided in two aliquots, one of which was used as a control and the other one processed by SLC. Assessment of sperm motility (assessed by computer-assisted semen analysis), morphology (Diff-Quick staining), viability (dual staining with propidium iodine/acridine orange), and acrosome integrity (dual staining with propidium iodine/isothiocyanate-labeled peanut [Arachis hypogaea] agglutinin) were performed on aliquots of fresh semen, frozen-thawed control samples, and frozen-thawed SLC-treated preparations. A multivariate clustering procedure separated 57,577 motile spermatozoa into three subpopulations (sP): sP1 consisted of poorly active and nonprogressive spermatozoa (48.8%), sP2 consisted of moderately slow but progressive spermatozoa (13.3%), and sP3 consisted of highly active and/or progressive spermatozoa (37.8%). SLC with Androcoll-C yielded sperm suspensions with improved motility, viability, and acrosome integrity (P < 0.01). The frozen-thawed SLC-treated samples were enriched in sP3, representing 38.5% of the sperm population. Likewise, sP2 was more frequently observed after SLC, but not significantly so. From these results, we concluded that for dog semen samples selected by SLC with Androcoll-C after thawing, the sperm quality parameters, including motility patterns, are better than in frozen-thawed control samples.     

Adaptation of ubiquitin-PNA based sperm quality assay for semen evaluation by a conventional flow cytometer and a dedicated platform for flow cytometric semen analysis

The purpose of semen quality evaluation is to predict the fertility potential of the sample in an objective, rapid and inexpensive manner. However, utilization of sperm quality biomarkers such as ubiquitin and lectin Arachis hypogaea agglutinin (PNA) for flow cytometric semen evaluation might eliminate the need for visual assessment by microscopy. Herein, we demonstrate a robust ubiquitin and PNA-based semen evaluation conducted on a simple, easy to operate, dedicated sperm flow cytometer, EasyCyte Plus (IMV Technologies, L'Aigle, France). Semen samples were collected periodically from two dairy bulls, which were subjected to temporary scrotal insults to induce variable semen quality. Samples were labeled with fluorescently-conjugated anti-ubiquitin antibodies (bind exclusively to the surface of defective sperm) and lectin PNA (binds to acrosomal surface in prematurely capacitated and acrosome-damaged sperm). Fluorescent properties of the samples were measured with a conventional flow cytometer (Becton Dickinson FACScan; Becton Dickinson Corp., Franklin Lakes, NJ, USA) and by the EasyCyte (IMV Technologies) instrument. Data from the two flow cytometers were positively correlated for the percentage of PNA-positive sperm with a damaged acrosome (r = 0.47; P < 0.001) and the percentage of ubiquitin-positive, defective sperm (r = 0.68; P < 0.001). Relative intensities of ubiquitin-induced fluorescence in cells with high ubiquitin levels were also positively correlated (r = 0.90). The proportion of sperm with abnormal morphology was positively correlated with ubiquitin-induced fluorescence measured by EasyCyte (IMV Technologies) (r = 0.63; P < 0.001). These observations provided a rationale for the adaptation of a dual ubiquitin-PNA sperm quality assay for flow cytometric semen evaluation.     

Effect of a bioengineered pseudorabies (Aujeszky's disease) vaccine on the semen quality of boars

Eight boars 11 months of age that were seronegative to pseudorabies virus were trained for hand collection of semen. A genetically engineered pseudorabies virus vaccine was given to 7 of 8 boars, while the eighth was left unvaccinated to serve as a control. Semen samples were collected at 7 day intervals from 42 days prior to vaccination through 49 days after vaccination. Rectal temperatures and general health of the boars were clinically normal throughout the trial, and no clear differences were observed in the quality of semen collected from the boars before or after vaccination. The semen samples were tested for vaccine virus and none was detected.     

Evaluation of superoxide dismutase activity and its impact on semen quality parameters of infertile men

The evaluation of superoxide dismutase (SOD) activity, as one of the most important antioxidative defence enzymes, in seminal plasma of patients consulting for male infertility was presented in the article. The study included also the determination of its influence on selected human semen quality parameters. The material represents semen samples obtained from 15 men, which were divided into two groups: Group I (n=10) including patients consulting for infertility and Group II (n=5) containing healthy sperm donors as a control. All of the semen samples were cryopreserved and stored in liquid nitrogen. The frozen samples were thawed at the same time and then SOD activity was determined spectrophotometrically. The analysis of the investigations results indicates a significantly lower semen SOD activity detected in oligoasthenozoospermic patients, comparing to the activity found in normospermic men. The study showed a positive correlation between SOD activity in seminal plasma and semen quality parameters--sperm concentration and overall motility, which are regarded as the most important for normal fertilizing ability of the spermatozoa. Significantly lower SOD activity in seminal plasma of infertile patients, comparing to healthy sperm donors, as well as positive correlation and beneficial impact of SOD activity on human semen quality parameters seem to confirm the observations, that decreased seminal plasma scavenger antioxidant capacity, particularly in form of low SOD activity, can be responsible for male infertility. This trial shows that SOD activity survey in seminal plasma could be a useful tool for determining sperm fertilization potential and could improve the diagnosis of male infertility.     

Sperm DNA fragmentation in boars is delayed or abolished by using sperm extenders

The semen quality of seven young adult boars was assessed for percentages of sperm motility, normal acrosomes, abnormal sperm, cells positive to sHOST (short Hipoosmotic Swelling Test), HPNA cells (sHOST Positive with Normal Acrosome cells) and the percentage of sperm heads, which exhibited DNA fragmentation using the Sperm Chromatin Dispersion test (SCD). These parameters were analysed in sperm samples both undiluted and diluted using a commercial extender and stored at 15 degrees C for 21 days. Results showed that semen quality decreases faster in the undiluted semen samples from day 0 to day 7 compared to diluted semen samples that remained with a high quality up to day 11. The undiluted semen exhibited a low DNA fragmentation index (DFI) during the first days and then a significant increase from day 7 up to day 21. This increase in the DFI coincided with the lowest levels of the other semen quality parameters. On the contrary, the samples diluted in the commercial extender showed very low levels of DNA fragmentation in all boars during the preservation period. When the evolution of DNA fragmentation was analysed in the undiluted samples, differences were found among boars. These differences were not shown in the samples diluted in the extender where the basal DFI remained stable during the 21 days. The main conclusion of this study was that some sperm extenders delay or partially prevent sperm DNA fragmentation.     

Relationship between sperm-zona pellucida binding assays and the 56-day nonreturn rate of cattle inseminated with frozen-thawed bull semen

Assays based on sperm-zona pellucida binding have been developed as diagnostic tests to predict the fertilizing potential of mammalian spermatozoa. Recently, we reported on the development of a sperm-zona pellucida binding assay (SZBA) for bull spermatozoa. The aim of the present study was to develop a hemi-zona assay (HZA) for bull spermatozoa and to investigate the relationship between SZBA and HZA outcomes and in vivo fertility. Frozenthawed semen samples from 8 fertile Swedish Red and White bulls (one ejaculate per bull) designated as the test semen samples and a single ejaculate from a fertile Holstein-Friesian bull designated as the control semen sample were used in this study. In the SZBA, 2 groups of 20 oocytes per semen test sample and in the HZA a minimum of 6 matching pairs of hemizonae were used for comparison of sperm binding with control semen. Sperm binding to matching hemi-zonae of individual semen samples was equal, and clearly demonstrated the feasibility of the HZA for cattle. A significant correlation was found between the SZBA and the HZA indices obtained from the different semen test samples (r = 0.42, P < 0.001; n = 67). There was no significant relation between the SZBA indices and the 56-d nonreturn rate of the test samples. However, the HZA indices of the semen test samples and the 56-d nonreturn rate were significantly correlated (r = 0.46, P < 0.0001; n = 67). It is concluded that HZA can be regarded as a potential assay for predicting the fertilizing ability of bovine semen samples. However, further studies using more semen samples are necessary to confirm this view.     

Viability and acrosome integrity of rabbit spermatozoa processed in a gelatin-supplemented extender

The effect of gelatin addition to the semen extender on the viability and acrosome integrity of rabbit spermatozoa was studied. Pooled semen samples were processed in a boar semen extender with or without gelatin addition. Semen samples were stored at 5 °C for 72 h. Viability and acrosome integrity was evaluated by light microscope. Results showed that gelatin addition had a significant positive effect on the quality of the stored semen.     

Semen changes in boars after experimental infection with porcine reproductive and respiratory syndrome (PRRS) virus

Eleven boars seronegative to porcine reproductive and respiratory syndrome virus (PRRSV) were trained for semen collection: five boars were inoculated intranasally with 6 x 10(6)TCID(50)/ml of PRRSV (Group A); four boars were inoculated intranasally with 6 x 10(4)TCID(50)/ml (Group B); and two boars were used as uninfected control (Group C). Semen samples were collected at 7-d intervals from 49 d prior to experimental inoculation with PRRSV to 70 d after inoculation, and were examined for sperm volume, sperm concentration, sperm morphology, sperm motility and for the presence of PRRSV. The infection in boars was demonstrated by the reisolation of PRRSV from the serum of all inoculated boars. Rectal temperatures and general health of the boars were clinically normal throughout the trial. Differences were observed in the quality of semen collected from boars after experimental infection with PRRSV. This infection induced a significant decrease in sperm motility and in spermatozoa with normal acrosomes. Of the semen samples tested for virus isolation in swine alveolar macrophages PRRSV was only isolated in 1 boar from Group B. The virus was detected in an additional semen sample in Group A by the production of an antibody titer in a biological assay. All attempts to detect PRRSV by RT-PCR in semen samples were unsuccessful. Nevertheless, from our study it is possible to suggest that the PRRSV can occasionally be transmitted in the semen during the initial phase of the disease.     

Quality of stallion semen obtained by a new semen collection phantom (Equidame) versus a Missouri artificial vagina

A study was performed to test a new semen collection device (Equidame phantom) that fractionates the ejaculate by comparing the quality of semen obtained by the Equidame phantom with that obtained by a Missouri artificial vagina. Semen from 4 Finnhorse stallions was collected 4 times per stallion by both methods. Half of the ejaculate was frozen and the other half extended and loaded into 2 Equitainer transport containers (24- and 48-h samples). Motility parameters were determined by a Hamilton-Thorn motility analyzer after cooled storage for 24 and 48 h and again after freezing/thawing. Raw and chilled semen samples were cultured and the number of bacterial colonies counted after incubations of 24 and 48 h. After a 24-h incubation the number of colony-forming units (CFU) in raw semen was significantly higher (P<0.01) when collected by the Missouri artificial vagina than by the Equidame phantom. After cooled storage, 75% of the semen samples contained no bacteria after an incubation of 24 h, and 69% yielded no growth after 48 h. The sperm-rich fractions (Cup 2) collected by the Equidame phantom had lower mean volumes (22.1 +/- 2.3 mL [+/- SEM] versus 101.6 +/- 9.3 mL) and significantly higher mean sperm concentrations (218.0 +/- 25.8 x 10(6) vs 86.2 +/- 8.1 x 10(6) cells/mL; P<0.05) than the total ejaculates collected by the Missouri device. The total and progressive motility of chilled and frozen-thawed semen did not differ significantly between collection methods. The Equidame phantom yielded semen that was of a lower bacteriological colony counts, but had sperm motility similar to that of semen collected with the traditional method by the Missouri artificial vagina.     

Influence of vedaprofen (Quadrisol) on quality and freezability of stallion semen

The objective of this study was to evaluate the effect of the non-steroidal anti-inflammatory drug (NSAID) vedaprofen (Quadrisol) on quality and freezability of stallion semen. Experiments were performed using 22 Franches Montagnes stallions from the National Stud in Avenches (Switzerland) randomly divided into a control and test group. Vedaprofen was given orally to all stallions of the test group at the recommended therapeutic dose (initial dose of 2mg/kg followed by 1mg/kg body weight every 12h) for 14 days. Control animals received the same amount of carrier substance. During treatment, blood samples of five stallions in both test and control group were collected for PGF(2 alpha)-metabolite (PG-metabolite) determination. Ejaculates from all stallions were collected and cryopreserved weekly for 14 weeks from September to December. Concentrations of PG-metabolite, PGF and PGE were measured in the seminal plasma of ejaculates collected 2 weeks before, during and 2 weeks after treatment. In fresh semen the volume, concentration, motility and number of normal sperm and sperm with major defects (acrosome defects, abnormal heads, nuclear vacuoles, proximal droplets, midpiece defects) were evaluated. In frozen-thawed semen samples motility as well as viability (SYBR-14/PI) were tested and the hypoosmotic swelling test (HOS) was performed. Results demonstrate that vedaprofen had no effect on blood plasma concentration of PG-metabolite but significantly inhibited both, PGF and PGE concentrations in seminal plasma. Furthermore, all quality parameters in fresh and frozen-thawed semen were not affected by vedaprofen treatment but the time of semen collection had a significant (P<0.05) effect on motility, normal sperm and sperm with nuclear vacuoles in fresh semen.     

Effect of sod (superoxide dismutase) protein supplementation in semen extenders on motility, viability, acrosome status and ERK (extracellular signal-regulated kinase) protein phosphorylation of chilled stallion spermatozoa

New studies are underway to find new methods for supporting longer storage of cooled stallion semen. It is known that high concentrations of reactive oxygen species (ROS) cause sperm pathology. The metalloprotein superoxide dismutase (SOD) is responsible for H₂O₂ and O₂ production, by dismutation of superoxide radicals. The aim of this study is to assess the quality of chilled stallion semen processed with extenders containing SOD at different concentrations as antioxidant additives. A total of 80 ejaculates collected from 5 standardbred stallions was divided into 5 aliquots treated as: native semen (control 1); native semen diluted 1:3 with Kenney semen extender (control 2); spermatozoa diluted after centrifugation in extender without (control 3) or with SOD at 25 IU/ml (experimental 1) or 50IU/ml (experimental 2). Each sample was analyzed for motility, viability and acrosome status, immediately after semen preparation and again after storage at 5 °C for 24h, 48h and 72h.Acrosome integrity was evaluated by Chlortetracycline (CTC) and Fluorescent-labeled peanut lectin agglutinin (PNA-FITC conjugated staining). A proteomic approach of quantifying extracellular signal regulated kinase (ERK) was also evaluated as an indirect indicator of oxidative stress. In all samples sperm progressive motility and sperm acrosomal integrity showed a significant reduction between fresh and cooled spermatozoa at 24h, 48h and 72h. Quality parameters of sperm were significantly higher (Progressive Motility P < 0.01; Viability P < 0.001) in aliquots supplemented with SOD. ERK phosphorylation was statistically higher (P < 0.01) in aliquots without SOD. The Authors concluded that addition of SOD to semen extenders improves the quality of chilled equine semen and reduces ERK activation.     

Impaired semen quality of AI bulls fed with moldy hay: a case report

The daily quality control of semen at a Finnish artificial insemination (AI) bull station is based on subjective motility and sperm morphology of young bulls entering the semen collection program. Semen quality dropped suddenly in autumn 1998. During 5 consecutive months, the number of rejected ejaculates and discarded frozen semen batches due to poor motility increased, and the number of all forms of abnormal spermatozoa increased. However, for the accepted ejaculates, a 60 day nonretum rate was normal. The summer of 1998 in Finland was rainy, and the hay used in the AI station was visibly moldy. Immunoassay and gas chromatography-mass spectrometry (GC-MS) detected Fusarium mycotoxins HT-2 and T-2, but no zearalenone in the hay. Occurrence of mycotoxins such as T-2 and HT-2 in the moldy hay coincided with, and may have been responsible for the impaired semen quality in AI bulls. This case report will draw the attention to the possible hazards when feeding moldy hay.     

Use of commercial extenders and alternatives to prevent sperm agglutination for cryopreservation of brown bear semen

The objective of this study was to evaluate different bovine and canine commercial semen extenders for cryopreservation of brown bear ejaculates and the effect of semen collection directly into extender on sperm agglutination. Semen samples were obtained by electroejaculation from 13 adult males. In experiment 1, eleven ejaculates from eight bears were used to evaluate Bioxcell and Andromed as extenders, whereas in experiment 2, nine ejaculates from six bears were used to evaluate Triladyl canine, CaniPro, and Extender 2 as extenders. An extender specifically developed for brown bears (Test-Tris-fructose-egg yolk-glycerol, TTF-ULE/bear) served as a control extender in both experiments. After thawing, total and progressive sperm motility and sperm viability were greater (P < 0.05) for TTF-ULE/bear and Andromed extenders than for Bioxcell in experiment 1 and greater (P < 0.05) for TTF-ULE/bear extender than for Triladyl Canine, CaniPro, and Extender 2 in experiment 2. In experiment 3, addition of handling extender (TTF-H) to the semen collection tube for eight ejaculates from seven bears resulted in less (P < 0.05) sperm agglutination in fresh samples (score 0.5 ± 0.2 vs. 1.8 ± 0.4 in diluted and control samples, respectively) with no effect on pre-freeze and post-thawing semen quality. In conclusion, TTF-ULE/bear is the most suitable extender for brown bear semen cryopreservation, but comparable results can be obtained with the commercial extender Andromed. In addition, collection of ejaculates directly in TTF-H extender decreases sperm agglutination in fresh samples.     

Effect of single layer centrifugation using Androcoll-E-Large on the sperm quality parameters of cooled-stored donkey semen doses

The aim of this study was to determine the effect of single layer centrifugation (SLC) using Androcoll-E-Large on donkey sperm quality parameters after 24 h of cool-storage. Ejaculates were collected from Andalusian donkeys and then cooled at 5°C. SLC was carried out after 24 h of cool-storage using Androcoll-E-Large. In the first experiment, all sperm parameters assessed (total and progressive sperm motility, viability, sperm morphology and sperm kinematics VCL, VSL, VAP, LIN, STR, WOB, ALH and BCF) were statistically compared between semen samples processed or not with Androcoll-E-Large. Significant differences (P<0.05) were found between SLC-selected and unselected semen samples for all parameters assessed, obtaining better results after SLC. In the second experiment, semen samples were classified in two groups according to their sperm progressive motility (PM) before SLC. Then, the increments obtained in semen quality parameters after SLC were compared between groups. No significant differences were found between groups, indicating that SLC improved the sperm quality parameters of entire set of semen samples processed with independence to their original PM. In conclusion, SLC with Androcoll-E-Large can be used in donkeys, increasing the sperm quality of cooled-stored donkey semen doses after 24 h of cool storage.     

The effects of drone age, semen storage and contamination on semen quality in the honey bee (Apis mellifera)

Abstract. The effect of semen storage time, drone age and semen contamination on honey bee semen quality was investigated using assays for motility and viability of semen in vitro. Four age groups (1, 2, 4 and 6 weeks) and five storage times (0, 1, 2, 4 and 6 weeks) were examined. As storage time increased, sperm viability and motility significantly decreased. However, motility patterns of unstored semen samples were significantly lower than those samples that were stored up to 2 weeks. Sperm viability decreased significantly with increasing drone age, but motility patterns did not change. Those semen samples that were found to be contaminated with foreign particles or microorganisms had a significantly lower mean viability than uncontaminated samples.     

Can external quality control improve pig AI efficiency?

External quality control programmes carried out by central laboratories have been long established in human andrology with the aim of enhancing the accuracy and reproducibility of semen assessment. Compared to human, demands on boar semen assessment in AI stations are more complex, with the need both to identify boars with poor ejaculate quality and to monitor individual boar differences for semen storage. Additionally, appropriate assessment serves as a control instrument to ensure the security and efficiency of semen processing. Despite current limitations regarding the ability of sperm assays to estimate the potential fertility of males, it is evident that boar fertility is related to certain conventional semen tests, e.g. sperm morphology. In central studies carried out on stored semen from 11 AI stations, flow cytometric assessment of plasma and acrosome membrane integrity proved to be more sensitive in detecting sperm damage associated with ageing and temperature stress as compared to light microscopy. Membrane integrity of stored semen differed between AI stations indicating significant influences of semen processing on sperm quality. Thus external control of semen quality in reference laboratories may be useful to monitor the efficiency of internal semen quality control in individual AI stations, to identify males with lower semen quality and/or poor response to semen storage, and to verify the precision of sperm counting. The possibility that central laboratories with sufficient resources may be able to identify functionally different responding sperm subpopulations for better estimation of fertility is discussed. Ideally, external quality control schemes for AI stations would comprise application of validated tests with high relevance for fertility (including bacterial status), analysis of semen processing on the AI station, and training courses for laboratory personnel.     

Processing stored stallion semen doses by Single Layer Centrifugation

The purpose of this study was to determine if the quality of stored stallion semen doses could be enhanced by the scaled-up version of Single Layer Centrifugation using Androcoll-E-Large. Three semen doses from each of fifteen stallions were transported overnight to the Swedish University of Agricultural Sciences (SLU) for processing 24 h after semen collection. Sperm quality in the resulting SLC-selected samples was significantly improved compared to the uncentrifuged samples: mean progressive motility was increased by 8% on the day of processing (P < 0.001) and by 13% after 24 h cold storage (P < 0.001), normal morphology was increased by 4% (P < 0.01), whereas mean %DFI was decreased by 2% (P < 0.001). When these SLC-selected samples were compared retrospectively to fresh samples processed by SLC with Androcoll-E Small, sperm quality was found to be similar, although it was not maintained for as long in the sperm samples stored before SLC. These results suggest an additional option for improving sperm quality in stallion semen doses for artificial insemination.