Semen quality in adult male survivors 5 years after the 2008 Wenchuan earthquake

The influence of the Wenchuan earthquake on semen quality of adult male survivors is unclear. We investigated the semen quality included 673 male survivors from the worse‐affected counties in the earthquake between Aug 2008 and July 2013. Semen parameters including pH, volume, concentration, motility and morphology were measured according to the World Health Organization (WHO) criteria. Kruskal–Wallis analysis of variance was used to examine the statistical differences between years, and a logistic regression was used to analyse the impacts caused by earthquake on the changes of semen quality. We found the medians (5th and 95th) were 2.5 ml (0.6–5.5) for semen volume, 59.0 × 10⁶ ml^?1 [(13.0–133.0)] × 10⁶ ml^?1 for semen concentration, 46% (13–64%) for sperm progressive motility and 3.0% (0–17.5%) for normal morphology for adult male survivors. Semen concentration, the percentage of sperm progressive motility, total motility and sperm normal morphology were all decreased in the first 3 years, and the differences among years 1, 2 and 3 were significant except the percentage of sperm progressive motility (P < 0.05). The casualties and heavy housing damage caused by earthquake had a negative effect on semen quality. The main findings will provide further diagnosis and therapy basis of male fertility by data, for affected populations in the earthquake.     

Anogenital distance and reproductive parameters in young men

The purpose of this study was to assess the relationship between anogenital distance (AGD) measures and semen quality and serum reproductive hormone levels in Caucasian young men from southern Spain. Two variants of AGD [from the anus to the posterior base of the scrotum (AGD_AS) and to the cephalad insertion of the penis (AGD_AP)] were assessed in 215 university students. Semen parameters (semen volume, sperm concentration, total sperm counts, motility and morphology) and serum reproductive hormones (follicle stimulating hormone, luteinising hormone, inhibin B, testosterone, calculated free testosterone, oestradiol and sex hormone‐binding globulin) were also determined. Associations between AGD measures and the semen quality and reproductive hormone levels were tested using multiple regression analyses. Overall, median sperm concentration was 44.0 × 10⁶ ml^?1 (5th–95th percentiles: 8.9–129 × 10⁶ ml^?1), median total sperm count was 121 × 10⁶ (18.0–400 × 10⁶), and mean (SD) testosterone level was 21.7 nmol/l (6.9). Mean (SD) AGD_AS and AGD_AP measures were 48.3 mm (11.6) and 128 mm (12.0) respectively. In the multivariable analysis, AGD measures were not associated with any semen parameters or any of the reproductive hormone levels, which is in contrast to results of studies of US young men or infertile men. Further research is warranted to confirm these findings.     

The reference values for semen parameters of 1213 fertile men in Guangdong Province in China

Semen samples were collected from 1213 fertile men whose partners had a time-to-pregnancy (TTP) ≤12 months in Guangdong Province in Southern China, and semen parameters including semen volume, sperm concentration, total counts, motility, and morphology were evaluated according to the World Health Organization (WHO) 2010 guideline. All semen parameters analyzed were normal in ~62.2% of the total samples, whereas ~37.8% showed at least one of the semen parameters below normal threshold values. The fifth centiles (with 95% confidence intervals) were 1.3 (1.2–1.5) ml for semen volume, 20 × 10⁶ (18×10⁶–20×10⁶) ml⁻¹ for sperm concentration, 40 × 10⁶ (38×10⁶–44×10⁶) per ejaculate for total sperm counts, 48% (47%–53%) for vitality, 39% (36%–43%) for total motility, 25% (23%–27%) for sperm progressive motility, 5.0% (4%–5%) for normal morphology. The pH values ranged from 7.2 to 8.0 with the mean ± standard deviation at 7.32 ± 0.17. No effects of age and body mass index were found on semen parameters. Occupation, smoking and alcohol abuse, varicocele appeared to decrease semen quality. Sperm concentration, but not sperm morphology, is positively correlated with TTP, whereas vitality is negatively correlated with TTP. Our study provides the latest reference values for the semen parameters of Chinese fertile men in Guangdong Province, which are close to those described in the new WHO guidelines (5^th Edition).     

Cryoprotective effect of l‐carnitine on motility,vitality and DNA oxidation of human spermatozoa

Successful cryopreservation for human spermatozoa markedly influences the reproductive outcomes of assisted reproductive technologies. But in spite of its usefulness, cryopreservation significantly decreases sperm quality. l ‐carnitine has been found to improve the quality of spermatozoa in selected cases with male infertility. Here, we examined the efficacy of l ‐carnitine in improving sperm motility and vitality and reducing sperm DNA oxidation during cryopreservation. Semen samples from infertile patients (n = 22) were collected and analysed. Cryopreservation medium supplemented with l ‐carnitine was mixed with the semen at a ratio of 1 : 1 (v/v). The final l ‐carnitine concentration in each cryovial was 0.5 mg ml^?1 per 5 × 10⁶ cell ml^?1. Controls were cryopreserved without addition of l ‐carnitine. After 24 h of cryopreservation, thawed sperm samples were analysed for motility, vitality and DNA oxidation. Sperm vitality was assessed by the eosin–nigrosin test, while sperm DNA oxidation was measured by flow cytometry. Addition of l ‐carnitine significantly improved sperm motility and vitality (P < 0.05) compared with the control. The flow cytometry experiment showed no statistical difference (P > 0.05) in the levels of DNA oxidation between samples and controls. In conclusion, l ‐carnitine improves human sperm motility and vitality, but has no effect on sperm DNA oxidation after cryopreservation.     

Antibiotic susceptibility of urogenital microbial profile of infertile men in South‐eastern Nigeria

Male factors are known to contribute significantly to the infertility problem. The urogenital bacteria profile and semen quality were investigated among 160 men attending infertility clinics in South‐eastern Nigeria. Both semen and urine samples were obtained from each subject and analysed according to standard techniques. A total of 16 (10%) had bacterial infection in their semen samples and individuals of older age groups were significantly affected (χ² = 23.18, P < 0.05). Urinary tract infection (UTI) was observed in 30.6% of subjects, with the highest rate occurring among men aged 36–40 years, but the difference was not significant (χ² = 7.62, P > 0.05). A total of 33.8% of the men had semen volume less than 2 ml per ejaculate, 33.8% also recorded total sperm count of <40 × 10⁶ ml^?1, while 36.3% recorded sperm motility <50%. Fifty‐three individuals (33.1%) had suboptimal sperm morphology (<60%), with the men aged 46–50 years old significantly affected (χ² = 13.03, P < 0.05). All the individuals with bacterial infection in semen also had UTI and suboptimal semen parameters. The commonest bacterial isolates were Proteus species, Staphylococcus aureus and Escherichia coli, which were resistant to most of the antibiotics assessed.     

Relationship of spermatozoal DNA fragmentation with semen quality in varicocele‐positive men

The aim of the study was to assess the semen quality and levels of spermatozoal nuclear DNA fragmentation in subfertile subjects clinically diagnosed with varicocele, subfertile subjects without varicocele and healthy fertile controls. Semen samples were obtained from 302 subjects. Of them, 115 were healthy fertile controls having normal semen characteristics, 121 subfertile men diagnosed with varicocele, both, clinically and on ultrasonography, while 66 subjects were subfertile with no varicocele. Spermatozoal concentration, percentage motility, morphology and DNA fragmentation were measured. In the study population, deterioration in semen quality‐decreased spermatozoal concentration, percentage motility and normal morphology was seen in subfertile subjects, especially with varicocele. Highest spermatozoal DNA fragmentation was observed in varicocele‐positive subjects as compared with varicocele‐negative subjects and healthy fertile controls. Significant negative correlation was seen between spermatozoal DNA fragmentation and concentration (r = ?0.310), motility (r = ?0.328) normal morphology, WHO method (r = ?0.221) and Tygerberg strict criteria (r = ?0.180) in the varicocele‐positive subfertile subjects. In conclusion, this study suggests existence of a negative relationship between spermatozoal DNA fragmentation and semen quality in varicocele‐positive subfertile subjects.     

The micronutrient supplements,zinc sulphate and folic acid,did not ameliorate sperm functional parameters in oligoasthenoteratozoospermic men

We investigated the effects of folic acid and zinc sulphate supplementation on the improvement of sperm function in subfertile oligoasthenoteratozoospermic (OAT) men. Eighty‐three OAT men participated in a 16‐week intervention randomised, double‐blind clinical trial with daily treatment of folic acid (5 mg day^?1) and zinc sulphate (220 mg day^?1), or placebo. Before and after treatment, semen and blood samples were obtained for determining sperm concentration, motility, and morphology, sperm viability, sperm mitochondrial function, sperm chromatin status using toluidine blue, aniline blue, acridine orange and chromomycin A₃ staining; and semen and blood folate, zinc, B₁₂, total antioxidant capacity ( TAC) and malondialdehyde (MDA) concentrations. Sperm concentration (×10⁶ ml^?1) increased in subfertile men receiving the combined treatment of folic acid and zinc sulphate and also in the group receiving only folic acid treatment; however, it was not statistically significant (P = 0.056 and P = 0.05, respectively). Sperm chromatin integrity (%) increased significantly in subfertile men receiving only zinc sulphate treatment (P = 0.048). However, this improvement in sperm quality was not significant after adjusting placebo effect. This study showed that zinc sulphate and folic acid supplementation did not ameliorate sperm quality in infertile men with severely compromised sperm parameters, OAT. Male infertility is a multifactorial disorder, and also nutritional factors play an important role in results of administration of supplementation on sperm parameters. However, these results should be confirmed by multiple studies in larger populations of OAT men.     

Effect of acute tadalafil on sperm motility and acrosome reaction: in vitro and in vivo studies

Effects of acute tadalafil on sperm motility and acrosome reaction were investigated, both in vitro and in vivo. Twenty asthenozoospermic and 20 normozoospermic patients as control were randomly enrolled. For in vitro part, 0.5 ml tadalafil solutions with different concentrations were added (0.2, 0.1, 0.05 and 0.025 μg ml^?1, respectively) into semen samples. In both groups, samples treated with 0.2 μg ml^?1 tadalafil had significant increase in sperm motility after 2 h incubation. For in vivo part, oral administration of tadalafil (20 mg) or sildenafil (100 mg) was given. In both groups, computer‐assisted semen analysis parameters showed no significant difference. After the administration of tadalafil (2 h) and sildenafil (1 h), there was no significant difference observed in premature acrosome reaction incidence rate. Taking both in vitro and in vivo results into consideration, acute on‐demand administration of tadalafil would have no adverse effect on semen parameters.     

Evaluation of semen quality in 1808 university students,from Wuhan,Central China

The aim of this study was to evaluate the semen quality of university students in Wuhan, the largest city in the world in terms of the number of university students. All student sperm donors recorded in the Hubei Province Human Sperm Bank from 1 March 2010 to 31 December 2013 were screened. At last, a total of 3616 semen samples from 1808 university student sperm donors were eligible and retrospectively analyzed. Each donor''s semen parameters were averaged over two samples and compared with the World Health Organization criteria, and a generalized linear regression model was used to examine several determinants of semen quality. We found that the mean and median values were 3.0 ml and 2.8 ml for semen volume, 50.2 × 10⁶ ml⁻¹ and 50.0 × 10⁶ ml⁻¹ for sperm concentration, 148.1 × 10⁶ and 142.1 × 10⁶ for total sperm count, and 58.6% and 60.0% for total sperm motility. About 85.0% of donors had parameters that were all normal. Season and duration of abstinence were critical factors affecting semen quality. We also found a decrease in sperm concentration during the 4 years observation; however, this may not be a strong evidence to confirm the declining trend of semen quality. In conclusion, semen quality of university students in Wuhan was not optimal and should be paid high attention, long-term observation and further study should be carried out to confirm the present situation.     

Serum oestradiol levels in male partners of infertile couples

A prospective clinical study was performed in the reproduction centre of Ichikawa General Hospital (Chiba, Japan) to investigate the relationship between sperm quality and serum oestradiol (E2) level in male partners of infertile couples. The semen parameters and blood samples were assessed in relation to several variables, including body mass index (BMI) and serum oestradiol (E2) levels. Four hundred and nine male partners of infertile couples aged 22–55 years (mean: 36.5 years) were referred to the reproduction centre. In total, 143 patients (35.0%) were included in the low E2 level group (18 pg ml^?1 ≥ E2). Serum E2 levels were slightly correlated with testosterone levels, BMI and serum FSH levels. Total motile sperm count and morphology were decreased in low E2 level group. In multivariate analysis, serum testosterone, E2 levels, existence of varicocele and age were risk factors for decreased semen quality. Serum E2 might be associated with BMI, serum testosterone level and spermatogenesis.     

Comparison of the semen analysis results obtained from two branded computer‐aided sperm analysis systems

The study evaluated the comparability of two branded computer‐aided sperm analysis (CASA) systems commonly used in andrology laboratories in China. The same semen sample was analysed using two branded CASA systems (WLJY‐9000 and CFT‐9200) by one well‐trained technician. Results of semen analysis obtained from two branded CASA systems were then compared. The accuracy of counting results of CASA systems was evaluated using latex bead solutions with known concentrations of (35 ± 5) × 10⁶ ml^?1 and (18 ± 2.5) × 10⁶ ml^?1. There were significant differences in all parameters (P < 0.01) except for LIN and WOB. The counting results of CFT‐9200 were close to the standard solutions [(38.86 ± 3.79) × 10⁶ ml^?1 and (19.03 ± 1.99) × 10⁶ ml^?1], while those of WLJY‐9000 were underestimated [(28.53 ± 2.06) × 10⁶ ml^?1 and (14.62 ± 0.95) × 10⁶ ml^?1]. But the coefficient of variation of WLJY‐9000 was lower than that of CFT‐9200 (7.22%, 6.50% vs. 9.82%, 10.46%). It is concluded that factors such as parameter settings and evaluation algorithms could significantly affect the results obtained from these two branded CASA systems. Great attention should also be paid to the quality control in semen analysis with CASA.     

Effect of levofloxacin treatment on semen hyperviscosity in chronic bacterial prostatitis patients

Changes in seminal fluid viscosity (SFV), reactive oxygen species (ROS) production, cytokines and seminal leucocyte concentration related to microbiological outcome in patients with chronic bacterial prostatitis (CBP) were studied. One hundred and ten infertile patients with CBP (positive sperm culture ≥10⁵ colony‐forming units [CFU] ml^?1, pathogens or Chlamydia in expressed prostatic secretions) were treated with levofloxacin 500 mg daily for 14 consecutive days per month for 3 months. In case of bacterial prostatitis, two conditions were examined: responders, eradication of 0 to <10³ CFU ml^?1 (n = 78) and poor responders, >10³ to <10⁵ CFU ml^?1 (n = 32). Compared with poor responders, responders showed a significant increase of sperm progressive motility and a significant decrease in seminal leucocyte count, SFV, liquefaction time, ROS production (in all fractions and conditions), seminal tumour necrosis factor‐α and interleukin 6. None of these variables showed significant differences compared with a control group of 37 fertile men. On the other hand, the poor responders showed significant changes in these variables compared with matched pretreatment values. In patients with CBP, antibiotic therapy alone leads to eradication in ≈71%, with improvement of sperm progressive motility, SFV and the framework of prooxidative factors. However, in the remaining ≈29% with poor antibiotic responsiveness, a deterioration of all variables is observed.     

Semen quality and infertility status can be identified through measures of oxidation–reduction potential

Standard analyses for evaluating semen quality require technical expertise and are interpretive in nature. Oxidative stress (OS) alters many of the semen parameters; thus, a measure of OS could be an indicator of semen quality. Static oxidation‐reduction potential (sORP) is a universal measure of OS traditionally used in environmental applications but is increasingly used in biomedical studies. sORP was measured to determine how well it associates with semen quality and if it differentiates semen from infertile patients and fertile donors. All study participants (Infertile, n = 365 and Fertile, n = 50) underwent standard semen analyses, and sORP was measured in unprocessed semen. In infertile patients, sORP increased with decreased total sperm number, motility and morphology. sORP values were higher in samples with abnormal quality (low number, motility and/or normal morphology) compared with those of normal quality. Infertile patients had higher sOPR values compared to fertile donors. A sORP cut‐off value of 1.38 mV/10⁶ sperm/ml can differentiate normal from abnormal semen samples, while a cut‐off value of 1.41 mV/10⁶ sperm/ml, can differentiate between infertile and fertile semen samples. In conclusion, sORP provides a quick and unbiased indicator of semen quality that can be a beneficial addition to semen analysis to determine semen quality and fertility status.     

Correlation of biochemical constituents of seminal plasma with semen quality in Teddy goat (Capra hircus) bucks

This study was planned to determine the relationship between semen quality parameters and the levels of biochemical constituents of seminal plasma of Teddy (Capra hircus) buck semen. For this purpose, semen ejaculates were collected from five mature healthy Teddy bucks. All the experimental bucks were kept under natural environmental conditions. Semen was collected twice in a week for the duration of 6 weeks by Artificial Vagina (AV) in the breeding season (February‐April). Two successive ejaculates of single buck were pooled at time of collection, and a total of 60 semen samples were processed for semen analysis. Sperm per cent motility, sperm concentration, dead sperm percentage, morphological abnormal spermatozoa, plasma membrane integrity were correlated with biochemical constituents of seminal plasma. The mean per cent motility (89.18% ± 0.37%), sperm concentration (1.86 ± 0.04 × 10⁹/ml), dead sperm percentage (8.08% ± 0.29%), morphological abnormal spermatozoa (6.05% ± 0.29%) and plasma membrane integrity (88.22% ± 0.34%) were recorded. The seminal plasma contained Na⁺ (144.12 ± 1.59 mEq/L), K⁺ (27.38 ± 0.49 mEq/L), Cl^? (65.73 ± 0.45 mEq/L), Ca⁺⁺ (9.34 ± 0.22 mg/dl), P (19.32 ± 0.97 mg/dl), aspartate aminotransferase (AST; 26.48 ± 1.30 IU/L), alanine aminotransferase (ALT; 168.47 ± 5.18 IU/L), lactate dehydrogenase (LDH; 215.98 ± 6.06 IU/L), albumin (1.90 ± 0.10 g/dl), globulins (2.08 ± 0.11 g/dl) and total protein (3.98 ± 0.20 g/dl). The collected data were analysed by applying Pearson's correlation coefficients. Dead sperm percentage had negative correlation with sodium (r = ?.278, p < .05), albumin (r = ?.294, p < .05), globulin (r = ?.266, p < .05) and total protein (r = ?.295, p < .05). Phosphorus was negatively associated with sperm concentration (r = ?.262, p < .05). AST was negatively correlated with plasma membrane integrity (r = ?.292, p < .05). It was concluded that most of the semen quality parameters of Teddy bucks were positively correlated with biochemical constituents, but opposite trends were found in case of dead sperm percentage. The seminal biochemical constituents dynamically interact with each other.     

Effect of pre-freezing conditions on the progressive motility recovery rate of human frozen spermatozoa

We evaluated the effects of sperm concentration, progressive motility, sperm morphology, duration of abstinence and collection season on the progressive motility recovery rate of human frozen spermatozoa to identify characteristics that predict the progressive motility recovery rate of human frozen spermatozoa and improve the protocol for sperm collecting in sperm banks. A total of 14 190 semen samples donated at Zhejiang human sperm bank of China between September 2006 and June 2011 were collected from 1624 donors. Semen was evaluated according to WHO standard procedures for sperm concentration. Progressive motility, sperm morphology, ejaculate collection season and abstinence time were recorded. After freezing and thawing, the progressive motility was assessed. Results showed that sperm concentration, progressive motility and normal morphology were significantly associated with the progressive motility recovery rate of human frozen spermatozoa. In addition, the abstinence time and collection season also significantly affected progressive motility recovery rate. Our results indicated that sperm concentration, progressive motility and normal morphology could be valuable in predicting the progressive motility recovery rate of human frozen spermatozoa. As such, progressive motility recovery may be improved by donating semen when abstinent for 3–5 days and during seasons other than summer.     

Milk,caseinate and lactoferrin addition to equine semen cooling extenders

Cooled semen has been used routinely to prolong sperm viability until artificial insemination time. However, spermatozoa are subjected to oxidative stress. The aim of the present work was to investigate the protective and antioxidant effect of the milk proteins lactoferrin (Lf) and caseinate added to equine semen cooling extenders. Semen from six stallions was cooled at 5 °C after resuspension with C1) milk‐ and glucose‐based, C2) 0.6% caseinate, C3) C2 + Lf 200 μg ml^?1, C4) C2 + Lf 500 μg ml^?1 and C5) C2 + Lf 1000 μg ml^?1 extenders, and kept at 5 °C for 24 h. Sperm motility characteristics and intact membrane rates were not different among the treatments (P > 0.05). As a result of the cooling process, the nitrite concentration increased significantly in the cooled semen (69.6 ± 78.9 μm per ×10⁶ spermatozoa) compared with the fresh semen (8.6 ± 1.9 μm per ×10⁶ spermatozoa). In contrast, the H₂O₂ concentrations were lower in the 0.6% caseinate extender (265.9 ± 221.3 μm per ×10⁶ spermatozoa) than in the milk extender (430.9 ± 199.8 μm per ×10⁶ spermatozoa, P < 0.05), showing an antioxidative effect of the caseinate compared with the milk. However, in all groups, hydrogen peroxide concentrations were similar to the undiluted fresh semen (332.8 ± 151.3 μm per ×10⁶ spermatozoa). Caseinate showed to be as efficient as milk to protect equine‐cooled spermatozoon.     

Consequences of bilateral cryptorchidism in adults

Bilateral cryptorchidism treatment results are often shadowed by the majority of unilateral cases. We report the long‐term follow‐up results of boys treated for bilateral cryptorchidism during childhood. Patients treated in two main paediatric surgery centres were selected from medical registries and invited for a clinical examination including scrotal ultrasound, salivary testosterone measurement and a semen sample. Thirty‐six men (38.3%) replied to the written invitation, and 21 agreed to be examined. The mean age at orchidopexy was 74 months (range 24–138). Sperm count was 0.42 × 10⁶ (SD ± 0.64 × 10⁶) ml^?1. The correlation between total testicular volume and total sperm count was statistically significant (r = 0.481; P = 0.032). These results show that surgical treatment of bilateral cryptorchidism after the age of 2 years does not prevent infertility. Sperm count and endocrine evaluation advocated after the treatment of bilateral cryptorchidism in all adult patients.     

Semen characteristics of transwomen referred for sperm banking before sex transition: a case series

Transwomen (TW) can now turn to cryopreserve spermatozoa before gender reassignment (GR). The objective is to assess semen quality of TW and evaluate adequacy for assisted reproduction technology (ART). Pre‐freezing (PF) and post‐thaw (PT) semen parameters of 2 and PF data of 27 TW who were referred for sperm banking in Cleveland Clinic/USA and Ghent Center/Belgium, before GR, were retrospectively analysed. The study period was between February, 2003 and October, 2011. We also evaluated adequacy of 24‐h PT data for ART. PF data of 29 TW, mean age of 28.9 years, showed high incidence of oligozoospermia (27.58%), asthenozoospermia (31%) and teratozoospermia (31%). Mean sperm concentration was 46.9 × 10⁶/ml, mean per cent motility was 42.9 and mean per cent sperm morphology (Kruger's) was 7.98. The 24‐h PT data, for 2 TW, showed mean motility 22.4%, mean total motile sperm count 13.7 × 10⁶ and total motile sperm concentration 8.7 × 106/ml. Single patient had used the frozen spermatozoon for intrauterine insemination (IUI) of a surrogate mother resulting in birth of healthy newborn. It is concluded that poor PF and 24‐h PT semen quality is frequently seen among TW. As such, considerable proportion of TW should use more expensive method of ART, for example IVF/ICSI rather than inexpensive IUI.     

Saturated,omega‐6 and omega‐3 dietary fatty acid effects on the characteristics of fresh,frozen–thawed semen and blood parameters in rams

The aim of this study was to investigate the effects of several dietary fatty acids (FAs) on semen quality and blood parameters in rams. We gave diet‐supplemented treatments (35 g day^?1 ram^?1) by C16:0 (palm oil), C18:2 [sunflower oil (SO)] and an n‐3 source [fish oil (FO)] to 12 rams, who were fed for 15 weeks during their breeding season. Semen was collected once per week. Semen samples were extended with Tris‐based cryoprotective diluents, then cooled to 5 °C and stored in liquid nitrogen. Positive responses were seen with FO after 4 weeks. The mean prefreezing semen characteristics improved with the intake of FO (P < 0.05). Interestingly, maximum sperm output in FO was achieved 7.5 × 10⁹ when compared to palm oil 5.3 × 10⁹. Rams that received FO had the highest total testosterone concentrations (11.3 ng ml^?1 for FO, 10.8 ng ml^?1 for SO and 10.2 ng ml^?1 for palm oil) during the experiment (P < 0.05). FO also improved the rams' sperm characteristics after thawing (P < 0.05). Although C16:0 is a major saturated FA in ram sperm and all rams have been fed isoenergetic rations, the unique FAs of FO improved fresh semen quality and freezing ability compared to other oils.     

Ultrastructure evaluation of goat spermatozoa after freezing in a skim milk‐based extender with Trolox supplementation

The aim of this work was to evaluate the in vitro effect of adding Trolox in freezing extender for goat semen. Ejaculates from five bucks were evaluated, and when approved, the samples were pooled, diluted according to experimental groups [Trolox 0 (control), 30, 60 and 120 nmol ml^?1] and frozen in an automated system. Thawed samples (37 °C/30 s) were evaluated for plasma membrane (PMi) and acrosome integrity (Aci), mitochondrial membrane potential (MMP) and sperm kinematics by CASA system. Spermatozoa ultrastructure was evaluated in fresh and post‐thawed semen. No significant difference (P > 0.05) was observed among control and Trolox groups in the analyses of PMi, Aci, MMP and CASA in goat spermatozoa after thawing. Samples of 60 and 120 nmol ml^?1 Trolox groups had a higher percentage of cells that had intact plasma membranes in spermatozoa head than in the other groups, although they did not differ (P > 0.05) before being frozen. A higher percentage (P < 0.05) of spermatozoa with intact mitochondria was observed in fresh semen, control and Trolox 60 nmol ml^?1 groups than in the other groups. Addition of Trolox to skim milk extender at 60 nmol ml^?1 ultrastructurally preserves the plasma membrane and mitochondrial sheath integrity in goat spermatozoa after cryopreservation.