Can in vitro embryo production be estimated from semen variables in Senepol breed by using artificial intelligence?

Thoroughly analyzing the sperm and exploring the information obtained using artificial intelligence (AI) could be the key to improving fertility estimation. Artificial neural networks have already been applied to calculate zootechnical indices in animals and predict fertility in humans. This method of estimating the results of reproductive biotechnologies, such as in vitro embryo production (IVEP) in cattle, could be valuable for livestock production. This study was developed to model IVEP estimates in Senepol animals based on various sperm attributes, through retrospective data from 290 IVEP routines performed using 38 commercial doses of semen from Senepol bulls. All sperm samples that had undergone the same procedure during sperm selection for in vitro fertilization were evaluated using a computer-assisted sperm analysis (CASA) system to define sperm subpopulations. Sperm morphology was also analyzed in a wet preparation, and the integrity of the plasma and acrosomal membranes, mitochondrial potential, oxidative status, and chromatin resistance were evaluated using flow cytometry. A previous study identified three sperm subpopulations in such samples and the information used in tandem with other sperm quality variables to perform an AI analysis. AI analysis generated models that estimated IVEP based on the season, donor, percentage of viable oocytes, and 18 other sperm predictor variables. The accuracy of the results obtained for the three best AI models for predicting the IVEP was 90.7, 75.3, and 79.6%, respectively. Therefore, applying this AI technique would enable the estimation of high or low embryo production for individual bulls based on the sperm analysis information.

Conditioned medium and secretome from epididymal epithelial cell cultures improve sperm kinetics and capacitation

Background and Aim

Sperm maturation occurs in the epididymis through interactions with existing molecules inside the lumen. However, the mechanism of epididymis molecular transfer is currently unclear. This study was aimed to determine the necessity of the epididymal epithelial cells (EECs) in the process of sperm maturation in terms of sperm kinetics and tyrosine phosphorylation.

Materials and Methods

A true experimental research design was used in this study. The medium tested was a primary culture of mice caput epididymal cells (cells and culture medium), conditioned medium (CM) (supernatant of EECs), and secretome (CM filtered at 0.22 μm). Sperm was cocultured in EEC culture, CM, and secretome for 1, 2, 3, or 4 h. The original culture medium was used as the control. Sperm kinetic analysis was performed after the indicated times using computer-assisted sperm analysis, and tyrosine phosphorylation was detected using the Western blot technique.

Results

A primary culture of caput EECs was successfully generated. The results showed increased sperm motility and progressive movement after 3 h of incubation (p < 0.05). There was a significant decrease in the average path velocity (VAP) values after 4 h of incubation (p < 0.05), but there was no significant change in the 1, 2, and 3 h incubation groups. The EEC culture-CM and secretome groups showed a significant increased progressivity and VAP percentage values compared with the control medium (p < 0.05). In terms of percentage motility, the culture and CM groups were significantly different from the control medium, but the secretome group was not.

Conclusion

The sperm kinetics of sperm cultured in CM, secretome, and EEC were significantly increased after 3 h of incubation, suggesting that CM and secretome can be used to replace EECs, especially when analyzing molecules secreted by the epididymal epithelium during sperm maturation. The results of this study highlight the potential of CM and secretome as therapy mediums for sperm kinetic abnormalities.

Effects of leukocyte elastase in semen on sperm quality

The study analyzed the effect of leukocyte elastase (LE) in 460 semen on sperm quality, and explore the reference interval of normal level of LE in semen. The differences of LE levels between normal semen and few, weak and abnormal semen were analyzed. Referring to domestic standards, the samples were divided into normal group (LE ≤ 250 ng/mL), occult infection (250 < LE ≤ 1000 ng/mL), and infection group (LE > 1000 ng/mL), and the differences in semen quality among the groups were compared. According to European standards, the samples were divided into normal group (≤600 ng/mL) and abnormal group (>600 ng/mL), and the differences in semen quality between the 2 groups were compared. The correlation between LE levels in semen and semen quality were analyzed. The positive rates of LE in the normal semen group and abnormal semen groups were 30.7% versus 34.7%, and there was no significant difference between the two groups (P > .05). When the semen divided into 3 groups, there was no significant difference between the physicochemical parameters, kinetic parameters, movement trajectory parameters, morphological parameters, and sperm DNA fragmentation index (DFI) (P > .05). There were significant differences in sperm morphology and sperm DFI between the two groups at 600 ng/mL (P < .05). Spearman correlation analysis showed that there was no significant difference between the level of LE in semen and physicochemical parameters, sperm kinetic parameters, sperm movement trajectory parameters, sperm morphological parameters, and sperm DFI (P > .05). It is appropriate to use 600 ng/mL as the threshold for the concentration of LE in semen; the correlation between the level of LE and sperm quality is not significant.

The effect of age and abstinence time on semen quality: a retrospective study

This study analyzed the effects of male age and abstinence time on semen quality and explored the best abstinence time for Chinese males among different age groups. Semen parameters, including sperm kinetics, morphology, and DNA fragmentation index (DFI), were reviewed from 2952 men. Samples were divided into six age groups (≤25 years, 26–30 years, 31–35 years, 36–40 years, 41–45 years, and >45 years) and were divided into six groups according to different abstinence time (2 days, 3 days, 4 days, 5 days, 6 days, and 7 days). The differences in semen quality between the groups were compared, and the effect of age and abstinence time on semen quality was analyzed. Significant differences were observed in semen volume, progressive motility (PR), and DFI among the age groups (all P < 0.05), and no significant differences were observed in sperm morphological parameters (all P > 0.05). There were significant differences in semen volume, PR, and DFI among different abstinence time groups (all P < 0.05) and no significant differences in sperm morphological parameters (all P > 0.05). Pearson analysis showed that male age and abstinence time were both significantly correlated with sperm kinetics and DFI (both P < 0.05), while no significant correlation was found with sperm morphological parameters (all P > 0.05). The box plots and histograms of men's age, abstinence time, and semen quality show that most semen quality parameters differ significantly between the 2 days and 7 days abstinence groups and other groups at different ages. Except for the sperm morphology parameters, sperm kinetic parameters and sperm DFI are linearly related to male age and abstinence time.

Effect of Extender, Storage Time and Temperature on Kinetic Parameters (CASA) on Bull Semen Samples

Simple Summary

The bull accounts for a great part of the economic value of beef herds managed with natural mating, with the Bull Breeding Soundness Evaluation (BBSE) performed in the field becoming essential. Part of the BBSE is the semen-quality evaluation (classical and kinetic parameters) that can be performed in situ (by trained practitioners) or at laboratories, with semen being short-term stored and shipped. The extender used as well as the storage temperature and duration may affect its quality. Thus, our aim was to explore the best conditions to preserve CASA kinetic parameters, to be reliably assessed afterwards. CASA parameters were preserved for up to 4–6 h post-ejaculation, except for AndroMed^® in most of the parameters. Motility decreased from 4–6 h up to 24 h, with the best values obtained with BIOXcell^® at 5 °C. The rest of kinetic parameters worsened when analyses were performed at 24 h. Therefore, we suggest evaluating seminal quality as soon as possible. However, using BIOXcell^®, either at 5 °C or room temperature, and INRA96^® at room temperature, sperm motility can be reliably evaluated for up to 6 h. These results help to fix adequate protocols for the short-term storage and shipment of bovine semen collected under field conditions.

Abstract

CASA kinetic parameters are often evaluated in a diagnostic centre. How storage conditions affect ejaculates up to evaluation is unclear. We assessed, in 25 commercial bulls electroejaculated in the field, the impact of time until evaluation (0–2 h, 4–6 h, and 24 h post-ejaculation), holding temperature (5 °C vs. room temperature), and extender (AndroMed^®, BIOXcell^® or INRA96^®) on CASA kinetic parameters. Total and progressive motility, VCL, VAP, VCL, ALH, BCF, STR, LIN, and WOB were assessed. CASA kinetic parameters were preserved for up to 4–6 h post-ejaculation, except for AndroMed^®. Regardless of extender or temperature, motility decreased from 4–6 h up to 24 h, with the best values obtained with BIOXcell^® at 5 °C. Our results suggest that BIOXcell^® can preserve sperm motility for up to 6 h, either at 5 °C or room temperature, and also INRA96^® at room temperature, with motility assessments and the percentage of the most rapid sperms being the lowest with INRA96^® at 5 °C. The kinetic parameters decreased when analyses were performed at 24 h. Therefore, we suggest evaluating seminal quality as soon as possible, before 6 h after collection. These results help to fix adequate protocols for the short-term storage and shipment of bovine semen collected under field conditions.

Relationships between Seminal Plasma Metabolites, Semen Characteristics and Sperm Kinetics in Donkey (Equus asinus)

Simple Summary

A deeper knowledge of reproductive biology may be helpful in the donkey to avoid the risk of extinction that some breeds are facing. The evaluation of metabolites in seminal plasma provides crucial information for the knowledge of donkey sperm metabolism, for obtaining comparative information with other species, as well as for providing useful elements for the formulation of extenders for sperm dilution and conservation. Moreover, correlations of seminal metabolites with sperm kinetics highlight new possible markers of sperm quality. Using multivariate analysis, all metabolic, seminal, and spermatic data were merged in a single dot that grouped individual stallions within clusters in the Cartesian axes according to the different spermatic characteristics. This amount of information also allows to shed light on the effects of total or partial removal of seminal plasma for improving sperm preservation. The inclusion in the study of an azoospermic individual represents a further discriminating element in the analysis of sperm quality under physiological and pathological conditions.

Abstract

This study aimed to evaluate donkey seminal plasma metabolites and relate this information to the main characteristics of sperm quality. Sperm kinetics from 10 donkey stallions were analyzed with a computerized system at the time of collection (T0) and after 24 h storage at 4 °C (T24). Seminal plasma was frozen at −80 °C for subsequent proton nuclear magnetic resonance (¹H NMR) spectroscopy. On three stallions, semen collection was repeated monthly for three times and sperm analysis also included mitochondrial activity and oxidative status. One stallion was azoospermic and a second semen collection was performed after one month. In the seminal plasma, 17 metabolites were identified; their levels showed numerous significant variations between the azoospermic and the normospermic individuals and grouped in well-defined clusters in a multivariate analysis. Comparing individuals with high and low sperm motility, the only discriminating metabolite was phenylalanine, whose levels were lower in the latter, as in the azoospermic individual. Phenylalanine was also the only metabolite highly correlated with all sperm kinematic parameters at T24. In conclusion, the present study has provided relevant information on the chemical characteristics of donkey semen, identified relationships between seminal metabolites, semen parameters, and sperm kinetics, and offered insights for future technological applications.

Effect of Quercetin Supplementation in Extender on Sperm Kinematics, Extracellular Enzymes Release, and Oxidative Stress of Egyptian Buffalo Bulls Frozen-Thawed Semen

Buffalo spermatozoa are more sensitive for cryopreservation compared to other species. This study aimed to evaluate the consequences of quercetin against cryodamage of buffalo frozen–thawed spermatozoa characteristics. Semen of Egyptian bulls (n = 4) was extended in OptiXcell extender incorporated with quercetin at 0 (control), 2.5, 5.0, 10.0, 20.0, 40.0, and 80.0 μM before cryopreservation. Frozen–thawed semen was evaluated for sperm motility by computer-assisted sperm analyzer (CASA), viability, morphology, membrane, and acrosome integrities. The kinematics parameters including average path velocity (VAP; μm/s), straight linear velocity (VSL; μm/s), curvilinear velocity (VCL; μm/s), amplitude of lateral head displacement (ALH; μm), beat cross frequency (BCF; Hz), linearity [LIN, (VSL/VCL) × 100], and straightness [STR, (VSL/VAP) × 100] were assessed. The sperm-free extender was evaluated for aspartate aminotransferase (AST), alanine aminotransferase (ALT), and H₂O₂. Homogenized sperm cells were evaluated for oxidative stress biomarkers [superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX)], and lipid peroxidation [malondialdehyde (MDA)]. The highest values of total motility, progressive motility, viability, intact acrosome, and membrane integrity substantially improved with 10 μM of quercetin. STR (%) was substantially low (P < 0.01), and VCL (μm/s) and ALH (μm) were markedly high (P < 0.05) in 10 μM of quercetin. The outflow of ALT enzyme to extracellular fluid was lower with 10 μM of quercetin (P < 0.001) and higher at 2.5 μM of quercetin. The spermatozoa leaked AST was markedly lower at 5.0, 10 (P < 0.001) and 20 μM (P < 0.05) of quercetin. The activity of antioxidant enzymes was eminently low at all quercetin concentrations, and this was accompanied by the decrease in H₂O₂ in the media. SOD activity at 10–80 μM, CAT at 5.0–40 μM, and GPX at 2.5–80.0 μM of quercetin in spermatozoa were substantially low. MDA level significantly (P < 0.001) decreased at all quercetin concentrations. In conclusion, the incorporation of quercetin at the level of 10 μM is promising in improving buffalo semen characteristics and lower the freezing–thawing oxidative stress.

Kinetic activity, membrane mitochondrial potential, lipid peroxidation, intracellular pH and calcium of frozen/thawed bovine spermatozoa treated with metabolic enhancers

Owing to the progressive decline of sperm motility during storage there is a need to find substances capable of enhancing sperm energy metabolism and motility and/or preserving it from oxidative damage. The aim of this study was to evaluate in frozen/thawed bovine spermatozoa the effect of several compounds, such as myo-inositol, pentoxifylline, penicillamine + hypotaurine + epinephrine mixture (PHE), caffeine and coenzyme Q10+ zinc + d-aspartate mixture (CZA), on either kinetic or metabolic parameters. Sperm kinetics was evaluated by Sperm Class Analyser whereas specific fluorochromes were used to evaluated mitochondrial membrane potential (MMP), intracellular pH, intracellular calcium concentration and lipid peroxidation. Lipid peroxidation was also evaluated by TBARS analysis. Treatments significantly affected total and progressive motility with different dynamics in relation to the incubation time. After the first hour of incubation, CZA treatment produced the best performance in total and progressive sperm motility as well as in curvilinear velocity, average path velocity and amplitude of head displacement, whereas pentoxifylline stimulated the highest straight-line velocity. MMP showed higher values (p < 0.01) after treatment with pentoxifylline and PHE. Intracytoplasmic calcium concentration and lipid peroxidation were significantly (p < 0.05) affected by the incubation time rather than the treatments. Intracellular pH varied significantly (p < 0.01) in relation to either the incubation time or treatments. In particular, it showed a progressive increase throughout incubation with values in control group significantly higher than in myo-inositol, PHE, caffeine, pentoxifylline and CZA groups (7.37 ± 0.03 vs. 7.29 ± 0.03, 7.28 ± 0.03, 7.26 ± 0.03, 7.22 ± 0.03 and 7.00 ± 0.03, respectively; p < 0.01).; however, among treatments, CZA displayed the lowest values. Significant correlations were found between sperm kinetic and metabolic parameters. These findings provide new comparative information on the effects of putative metabolic enhancers on kinetics and metabolic activities of bovine spermatozoa. In this study, a rapid methodological approach for evaluating sperm quality is proposed.

Prognostic value of objective semen parameters in an in vitro fertilization program

PURPOSE

The basic semen parameters seem to have a limited predictive value in male fertility. Could other objective sperm analyses be helpful in the choice of the most adapted assisted procreation technique?

METHODS

This study concerns 78 infertile couples with insemination failures. For each semen, 21 objective parameters are analyzed in fresh semen and after sperm selection procedure. The 78 couples are then included in an IVF protocol and classified into two groups: fertile (at least one cleaved embryo is obtained) and infertile.

RESULTS

Using multiple variant discriminant factorial analysis, we have found nine nonconventional parameters which induce us to define two classes of semen. These two classes fit with the classification into fertile and infertile groups in 74.4% of the cases.

CONCLUSIONS

So these parameters allow us to predict the chance of obtaining embryos during an IVF trial and to choose for each couple the most appropriate technique: IVF or ICSI.