Can detomidine replace medetomidine for pharmacological semen collection in domestic cats?

Among the different methods used for semen collection from domestic cats, the pharmacological collection by urethral catheterization becomes disruptive. Medetomidine is the elected α²-adrenoceptor agonist for that, but in several countries, it is not commercially available. This study aimed to evaluate the efficacy of detomidine compared to medetomidine in collecting semen by urethral catheterization in domestic cats. Urethral catheterization was performed on 13 mongrel cats using a disposable semi-rigid tomcat urinary catheter. Of the 19 semen collections performed with medetomidine induction, 94.7% were successful, while with detomidine induction, only 56.3% of 16 were successful. The values semen samples variables were as follows for volume - 10.56 ± 0.4 vs 8.88 ± 0.5 mL, motility - 171.67 ± 0.79 vs 49.77 ± 3.45%, vigor – 4.1 ± 0.03 vs 3.10 ± 0.1 and concentration - 3.24 ± 0.19 vs 2.15 ± 0.13 ×10⁹ sperm/mL respectively for medetomidine and detomidine group. The failure in semen collections with detomidine was mainly due to azoospermic samples, poor urethral relaxation, insufficient volume, or contamination of urine. The sperm concentration was also lower in the detomidine group (P <0.05) when compared to medetomidine. However, when the volume of semen collected was compared, we found no statistical differences. Despite its low performance in collecting semen from cats, detomidine may be an alternative when medetomidine is not accessible.     

Seasonal influence on semen traits and freezability from locally adapted Curraleiro bulls

Studies were conducted to characterize the effect of season of the year on testicular morphology, fresh and frozen/thawed semen quality from Curraleiro (Pé-duro) bulls in the Brazilian Central west region. Five adult, healthy bulls underwent an andrological examination and semen collection using an electroejaculator, once a month for a year. Fresh and thawed semen were evaluated for progressive sperm motility and sperm vigor, sperm morphology and acrosomal integrity. Testicular length and volume were less (P<0.05) in April than in the other months of the year. For fresh semen, the ejaculate in April had less volume and sperm concentration (P<0.05), while sperm vigor was less (P<0.05) in June, increasing in January and February. With the frozen/thawed semen, the proportion of sperm was greater (P<0.05) in April to July, decreasing from October to December. Semen collected in December had the greatest (P<0.05) proportion of major defects while that collected in February/March had the highest proportion of minor defects. The proportion of live intact sperm reduced progressively from December to April/May. The marginal influence of the time of the year on testicular biometry and fresh semen in Curraleiro bulls shows the adaptation of this breed to the environmental conditions in the region. Thus, reproduction with natural mating should be successful at any time of year. For frozen semen collection for conservation programs, the best time of year is from June to September.     

Simple and Effective Methods of Freezing Capercaillie (Tetrao urogallus L.) Semen

A continuous decline in the number and range of capercaillie (Tetrao urogallus L.) in many European countries can be observed, mostly due to habitat destruction by human activity, unecological forestry management, and increased density of natural predators. Ex situ in vitro gene banks provide a unique opportunity to preserve the genetic material for future generations. Simple and effective cryopreservation methods for capercaillie semen are discussed. Semen was collected from seven males kept in the Capercaillie Breeding Centre at Forestry Wisła in Poland. Within five minutes after collection, ejaculates were diluted with EK diluent, then divided into two parts, and subjected to two freezing procedures: in pellets and in straws. In fresh semen, ejaculate clearness, viscosity, color and volume, as well as sperm concentration, motility and morphology, were evaluated, while in frozen-thawed semen only motility and morphology of sperm were determined. Fertilizing ability of thawed semen was examined for samples frozen in straws. Significant (P<0.05) differences between individual males were found in relation to the majority of fresh semen traits: ejaculate volume averaged 102.1 µL (varying from 49.0 to 205.0); average sperm concentration was 632.5 x10⁶ mL^-1 (178.8–1257.1); percentage of live normal cells varied from 39.2 to 70.3% (58.7% on an average); percentage of motile cells ranged from 76.0 to 85.7%) and motility parameters were male dependent, as well. Both cryopreservation methods had a negative effect on morphology and motility of frozen-thawed semen; however, the straw method yielded 60.7% and the pellet method 42.5% of live cells in total in thawed semen (P<0.05), while the number of live normal (intact) cells was similar (22.4 and 22.2%, respectively). Egg fertility varied between 77.8 and 91.7% (average 84.4%). Both freezing procedures seem to be effective in obtaining acceptable viability and high fertilizing potency of thawed sperm and can be used to create a gene bank of capercaillie semen.     

A training program for noninvasive semen collection in captive western lowland gorillas (Gorilla gorilla gorilla)

Staff at Omaha's Henry Doorly Zoo devised a training program for noninvasive semen collection from three male gorillas. Trained behaviors, shaped using food rewards and verbal praise, enabled the trainer to perform a cursory physical examination and collect >270 semen samples during the study period. Ejaculate volume, sperm motility, and progressive forward motion were recorded. Two of the gorillas regularly produced semen samples that were cryopreserved. Frozen semen from one gorilla was successfully used in an assisted reproductive procedure. The training program may be used as a guideline for other institutions to create similar programs. Zoo Biol 17:143–151, 1998. © 1998 Wiley-Liss, Inc.     

Characteristics and seasonal variation in the semen of Markhoz bucks in western Iran

The aims of the present study were to evaluate if seasonality in semen characteristics and plasma testosterone concentrations exist in Markhoz male goats. Ten Markhoz (Angora) bucks were housed and fed according to standard recognized practices. During the observation period, semen was collected monthly with the aid of an electro-ejaculator and examined microscopically immediately after collection. Physical parameters of semen and the semen index were recorded. Blood samples were also taken monthly throughout the observation period and the plasma testosterone concentration monitored. Bucks demonstrated a higher semen quality (P < 0.05) in autumn and summer (semen index of 965 × 10⁶ and 752 × 10⁶ ml⁻¹, respectively), compared to spring and winter (semen index of 606 × 10⁶ and 512 × 10⁶, respectively). This coincided with a higher (P < 0.05) plasma testosterone concentration in autumn and summer (8.1 and 10.1 ng ml⁻¹, respectively), compared to that obtained in spring (3.0 ng ml⁻¹) and winter (2.5 ng ml⁻¹). During autumn and summer, the ejaculate volume (average of 1.2 and 1.0 ml), sperm output (1159 × 10⁶ and 1005 × 10⁶ sperm ml⁻¹), sperm mass motility (4.2 and 4.3), sperm progressive motility (83.9 and 82.0%) and percentage live sperm (90.7 and 88.2%, respectively) of the bucks were higher (P < 0.05) than in the spring (0.6 ml, 880 × 10⁶ sperm ml⁻¹, 3.3, 71.5% and 80.2%) and winter (0.7 ml, 863 × 10⁶ sperm ml⁻¹, 4.0, 71.5% and 84.9%, respectively). During autumn and summer, the percentage of sperm abnormalities (5.0 and 9.2%) was significantly lower than that in spring (12.9%) and winter (11.2%). The semen pH was slightly alkaline being significantly (P < 0.05) lower in the autumn (7.1) than in spring (7.3). Data showed season of the year to influence all semen parameters evaluated—indicating that optimal buck performance may be obtained in late summer and autumn. It can thus be said that Markhoz bucks have distinct seasonal spermatogenic activity, with poorer semen characteristics being recorded during winter and spring. This may be a critical obstacle when implementing an intensive breeding system of three kidding seasons in 2 years, with natural mating being implemented.     

Quality and fertility of cooled-shipped stallion semen at the time of insemination

Stallion semen processing is far from standardized and differs substantially between AI centers. Suboptimal pregnancy rates in equine AI may primarily result from breeding with low quality semen not adequately processed for shipment. It was the aim of the study to evaluate quality and fertility of cooled-shipped equine semen provided for breeding of client mares by commercial semen collection centers in Europe. Cooled shipped semen (n = 201 doses) from 67 stallions and 36 different EU-approved semen collection centers was evaluated. At arrival, semen temperature was 9.8 ± 0.2 °C, mean sperm concentration of AI doses was 68 ± 3 x 10⁶/ml), mean total sperm count was 1.0 ± 0.1 x 10⁹, total motility averaged 83 ± 1% and morphological defects 45 ± 2%. A total of 86 mares were inseminated, overall per season-pregnancy rate in these mares was 67%. Sperm concentration significantly influenced semen motility and morphology at arrival of the shipped semen. Significant effects of month of the year on volume, sperm concentration and total sperm count of the insemination dose were found. The collection center significantly influenced all semen parameters evaluated. Semen doses used to inseminate mares that became pregnant had significantly higher total and progressive motility of spermatozoa and a significantly lower percentage of morphological semen defects than insemination doses used for mares failing to get pregnant. Results demonstrate that insemination with semen of better quality provides a higher chance to achieve pregnancy. Besides the use of stallions with good semen quality, appropriate semen processing is an important factor for satisfying results in artificial insemination with cooled-shipped horse semen.     

Lactotransferrin in Asian Elephant (Elephas maximus) Seminal Plasma Correlates with Semen Quality

Asian elephants (Elephas maximus) have highly variable ejaculate quality within individuals, greatly reducing the efficacy of artificial insemination and making it difficult to devise a sperm cryopreservation protocol for this endangered species. Because seminal plasma influences sperm function and physiology, including sperm motility, the objectives of this study were to characterize the chemistry and protein profiles of Asian elephant seminal plasma and to determine the relationships between seminal plasma components and semen quality. Ejaculates exhibiting good sperm motility (≥65%) expressed higher percentages of spermatozoa with normal morphology (80.3±13.0 vs. 44.9±30.8%) and positive Spermac staining (51.9±14.5 vs. 7.5±14.4%), in addition to higher total volume (135.1±89.6 vs. 88.8±73.1 ml) and lower sperm concentration (473.0±511.2 vs. 1313.8±764.7×10⁶ cells ml⁻¹) compared to ejaculates exhibiting poor sperm motility (≤10%; P<0.05). Comparison of seminal plasma from ejaculates with good versus poor sperm motility revealed significant differences in concentrations of creatine phosphokinase, alanine aminotransferase, phosphorus, sodium, chloride, magnesium, and glucose. These observations suggest seminal plasma influences semen quality in elephants. One- and two-dimensional (2D) gel electrophoresis revealed largely similar compositional profiles of seminal plasma proteins between good and poor motility ejaculates. However, a protein of ∼80 kDa was abundant in 85% of ejaculates with good motility, and was absent in 90% of poor motility ejaculates (P<0.05). We used mass spectrometry to identify this protein as lactotransferrin, and immunoblot analysis to confirm this identification. Together, these findings lay a functional foundation for understanding the contributions of seminal plasma in the regulation of Asian elephant sperm motility, and for improving semen collection and storage in this endangered species.     

Comparison of electroejaculation and transrectal massage for semen collection in range and yearling feedlot beef bulls

Two experiments were conducted to compare electroejaculation (EE) and transrectal massage (RM) of the ampullary region for semen collection from beef bulls, and to determine the effect of semen collection method on semen traits. In experiment 1, semen was collected either by EE or RM randomly assigned on an alternate basis in 137 range beef bulls unaccustomed to being handled. The maximum time allowed for RM was 4 min and if no semen was obtained, EE was used. In experiment 2, semen was collected from 39 yearling feedlot beef bulls that were accustomed to being handled, by RM followed immediately by EE. The maximum time allowed for semen collection by both methods was 4 min. In both experiments, sperm concentration, percent of progressively motile sperm, percent of sperm staining alive, and sperm morphology were determined. In experiment 1, RM resulted in fewer (P<0.001) successful semen collections and fewer bulls with penile protrusion than EE (80.9% versus 100% and 54.4% versus 91.5%, respectively). The success of RM was not influenced by bull age or breed, or by the veterinarian performing the massage. Transrectal massage required more time (30s, P<0.001) for obtaining a semen sample and resulted in samples with lower sperm concentration (P<0.001), percent motile sperm (P<0.05) and percent live sperm (P<0.001) when compared to EE. In experiment 2, EE and RM were equally effective for obtaining a semen sample (97.4 and 94.9%, respectively), but the proportion of bulls exhibiting penile protrusion during semen collection was lower (P<0.0001) with RM compared to EE. Percent of sperm staining alive was also lower (P<0.01) in samples collected by RM. Sperm morphology (normal sperm, head defects, midpiece defects, proximal cytoplasmic droplets, and detached sperm heads) did not differ between samples collected by EE and RM. In conclusion, semen could be collected by transrectal massage from approximately 80% of range beef bulls and from 95% of yearling beef bulls accustomed to handling. Sperm morphology was not affected by the method of semen collection, but percent of motile sperm and live sperm were lower in samples collected by RM. A reduced ability to stimulate penile protrusion with RM precluded examination of the penis in a large proportion of bulls.     

Comparative Examination of Capercaillie (Tetrao urogallus L.) Behaviour Responses and Semen Quality to Two Methods of Semen Collection

Artificial insemination (AI) is very helpful in solving the reproductive and biodiversity problems observed in small, closed avian populations. The successful production of fertilized eggs using AI is dependent on the collection of good quality semen. Two methods of male sexual stimulation and semen collection from captive kept capercaillie (Tetrao urogallus L.), one of the most seriously endangered grouse species in Europe, are compared in this study. Ejaculates were obtained either with the use of a dummy female or by the dorso-abdominal massage method. Differences in the individual responses of the males to the two methods of semen collection as well as in their semen quality were noted. Only sperm concentration (432.4 x 10⁶ mL^-1 with dummy female and 614.5 x 10⁶ mL^-1 for massage method) was significantly affected by capercaillie stimulation method. Sperm motility and morphology were not affected (P≥0.05). Thus, for semen collection from captive kept capercaillie both methods can be used successfully. The dummy female can be an alternative to dorso-abdominal massage method, commonly used for semen collection from domesticated bird species.     

The Effect of Chronic Prostatitis/Chronic Pelvic Pain Syndrome (CP/CPPS) on Semen Parameters in Human Males: A Systematic Review and Meta-Analysis

Background

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is one of the risk factors of impaired male fertility potential. Studies have investigated the effect of CP/CPPS on several semen parameters but have shown inconsistent results. Hence, we performed a systematic literature review and meta-analysis to assess the association between CP/CPPS and basic semen parameters in adult men.

Methods

Systematic literature searches were conducted with PubMed, EMBASE and the Cochrane Library up to August 2013 for case-control studies that involved the impact of CP/CPSS on semen parameters. Meta-analysis was performed with Review Manager and Stata software. Standard mean differences (SMD) of semen parameters were identified with 95% confidence intervals (95% CI) in a random effects model.

Results

Twelve studies were identified, including 999 cases of CP/CPPS and 455 controls. Our results illustrated that the sperm concentration and the percentage of progressively motile sperm and morphologically normal sperm from patients with CP/CPPS were significantly lower than controls (SMD (95% CI) −14.12 (−21.69, −6.63), −5.94 (−8.63, −3.25) and −8.26 (−11.83, −4.66), respectively). However, semen volume in the CP/CPPS group was higher than in the control group (SMD (95% CI) 0.50 (0.11, 0.89)). There was no significant effect of CP/CPPS on the total sperm count, sperm total motility, and sperm vitality.

Conclusions

The present study illustrates that there was a significant negative effect of CP/CPPS on sperm concentration, sperm progressive motility, and normal sperm morphology. Further studies with larger sample sizes are needed to better illuminate the negative impact of CP/CPPS on semen parameters.     

Docosahexaenoic acid in diluent for goat semen cryopreservation

The effects of docosahexaenoic acid (DHA) in the diluent for cryopreservation of goat semen on seminal quality and the optimal levels to be used were evaluated. After collection, semen was pooled and physically evaluated, then divided into four aliquots with different DHA levels in the diluent: 0, 10, 20, and 30 ng mL^-1. The semen was cryopreserved in a TK 3000® freezing machine and then thawed for assessment at 37 °C. Sperm motility and vigor, membrane integrity, acrosomal integrity, mitochondrial activity, and sperm chromatin compaction were evaluated after thawing. A completely randomized design was used. For normally distributed variables, ANOVA and regression analysis were used to test for differences between treatments, and for non-parametric data, the Kruskal Wallis test was used at the 5% significance level. There were no differences among groups in terms of membrane integrity, acrosomal integrity, or chromatin compaction. There was a decrease in class I mitochondrial activity with increasing DHA level (P<0.05), but no differences in classes II, III, and IV (P>0.05). The inclusion of 10 to 30 ng mL^-1 of DHA in the diluent did not result in improvements in seminal quality parameters after thawing, with some impairment observed in the mitochondrial activity of the sperm cells.     

Noninvasive semen collection from an adult orangutan

Preservation of the genetic diversity of the captive orangutan, especially the wild-caught founders, is critical in maintaining a long-term population in zoological parks. One solution to the problem of maintaining maximum genetic diversity would be to initiate a program of artificial insemination for genetically underrepresented individuals through the banking and interinstitutional use of cryopreserved semen. However, little is known about basic orangutan semen characteristics, and current methodology is inadequate to support such a program. In this paper, we report the results of semen collection from an adult Sumatran orangutan (Pongo pygmaeus abelli), using an artificial vagina without anesthesia or electrical stimulation. A total of 27 ejaculates were evaluated during a 1-year period. The total and liquid volumes of the ejaculates at 1 h following collection were 6.1 ± 0.6 ml and 2.6 ± 0.4 ml, respectively (mean ± SEM). The liquid portion continued to exude semen for 2 h; however, 90% of the motile sperm was exuded within the first 30 min. The total number of sperm in the ejaculate was 164 ± 10⁶ ± 16.5, and the percentage of motile cells was 60 ± 2.7%. We conclude that the artificial vagina provides a promising technique for semen collection in the orangutan, and view these results as an initial step in developing methods for in vitro sperm capacitation, sperm cryopreservation, and artificial insemination. © 1993 Wiley-Liss, Inc.     

The Use of In Vitro Fertilization in the Management of Male Infertility: What the Urologist Needs to Know

Infertility affects approximately 10% to 20% of reproductive-age couples, many of whom may present initially to a urologist. Some couples may be treated medically to increase spontaneous conception rates; however, many will require more aggressive management with in vitro fertilization (IVF) and/or intracytoplasmic sperm injection (ICSI). IVF involves ovarian stimulation, oocyte retrieval, and fertilization outside of the body; ICSI involves injecting one sperm into the oocyte to promote fertilization. Here we provide a brief overview of IVF and ICSI along with a discussion of the risks involved to facilitate the counseling and care of the infertile couple.Key words: Intracytoplasmic sperm injection, Male infertilityInfertility, defined as the inability to conceive within 12 months of unprotected intercourse, affects approximately 10% to 20% of reproductive-age couples.¹ As couples defer childbearing until later ages and as the obesity epidemic grows, the incidence of infertility is likely to continue to rise.^2,3 Male factor infertility is estimated to contribute to two-thirds of all cases. Of men seeking care for infertility, 18.1% reported being diagnosed with male factor infertility and 13.7% with a sperm or semen problem.⁴The evaluation for male infertility includes a thorough history and physical examination, and the mainstay of diagnostic testing continues to be the semen analysis. If abnormalities are noted on semen analysis, further testing is warranted to evaluate for possible etiologies. Where applicable, treatment is initiated with the goal of improving semen quality and male fertility. Previously, in cases in which semen quality remained profoundly impaired, the successful treatment for male factor infertility was once limited to donor insemination.The development of in vitro fertilization (IVF) revolutionized the management of female infertility. As powerful a tool as this proved to be, however, IVF fertilization rates remained poor in the presence of compromised semen parameters. A significant breakthrough in the treatment of severe male infertility was the development of intracytoplasmic sperm injection (ICSI) in 1992.⁵ By allowing the injection of a single sperm into each oocyte, ICSI provides the possibility of genetic offspring to men who have very scant numbers of motile sperm on semen analysis or who require surgical harvesting.From its inception, assisted reproduction has involved a gynecologist and an embryologist. The urologist is a critical collaborator for the treatment of couples with male factor infertility. Sperm harvested by microsurgical epididymal sperm aspiration, testicular sperm aspiration, or biopsy can be used to fertilize harvested oocytes by ICSI. The urologist may be the first to evaluate a couple for infertility, and will certainly be involved if sperm harvesting is indicated. Therefore, this article reviews the process of assisted reproduction by IVF/ICSI for urologists who may be seeing patients with infertility issues.     

Sperm motility parameters for Steindachneridion parahybae based on open‐source software

The objective of this work was to evaluate the sperm motility of 13 Steindachneridion parahybae males using open‐source software (ImageJ/CASA plugin). The sperm activation procedure and image capture were initiated after semen collection. Four experimental phases were defined from the videos captured of each male as follows: (i) standardization of a dialogue box generated by the CASA plugin within ImageJ; (ii) frame numbers used to perform the analysis; (iii) post‐activation motility between 10 and 20 s with analysis at each 1 s; and (iv) post‐activation motility between 10 and 50 s with analysis at each 10 s. The settings used in the CASA dialogue box were satisfactory, and the results were consistent. These analyses should be performed using 50 frames immediately after sperm activation because spermatozoa quickly lose their vigor. At 10 s post‐activation, 89.1% motile sperm was observed with 107.2 μm s^?1 curvilinear velocity, 83.6 μm s^?1 average path velocity, 77.1 μm s^?1 straight line velocity; 91.6% were of straightness and 77.1% of wobble. The CASA plugin within ImageJ can be applied in sperm analysis of the study species by using the established settings.     

Effects influencing boar semen

The aim of this study was to analyze the main influences on the quality and quantity of boar semen. A total of 230,705 records of semen collections were utilised to estimate statistics of semen traits of 2712 boars belonging to the following breeds: Czech Meat Pig, Duroc, Hampshire, Landrace, Large White, Czech Large White and Pietrain, and various crosses of these breeds. The evaluation was based on semen volume (VO), concentration of spermatozoa (CO), progressive motion of spermatozoa (MO), abnormal spermatozoa (AB), total number of spermatozoa (NO_T) and corrected number of spermatozoa (NO_C). The breeds differed significantly for all examined traits. The maximal differences between the breeds were 95 ml for VO, 109 × 10³ mm⁻³ for CO, 9% for MO, 1.6% for AB, 24 × 10⁹ for NO_T and 19 × 10⁹ for NO_C. The maximal heterosis effect reached 12% for VO, 17% for CO, 4% for MO, −14% for AB, and 8% for NO_T and NO_C. The results demonstrate that the year-season effect has a clear effect on semen quality. The lowest values of semen traits were observed in summer while the highest values were found in autumn and winter. Age of boar was found to have a strong impact on sperm output. Sperm output tended to increase up to a boars’ age of 3.5 years. An acceptable level of semen volume occurred after a sexual pause of 3 days and the pool of spermatozoa was restoring after 5–7 days and fully after 10–11 days.     

Evaluation of anesthetic protocol for the collection of semen from captive collared peccaries (Tayassu tajacu) by electroejaculation

The objective of this study is to verify and compare the effects of acepromazine–tiletamine–zolazepam and propofol used in anesthetic protocols for semen collection by electroejaculation from captive collared peccaries. Ten sexually mature animals were physically restrained and anesthetized by either intravenous administration of tiletamine–zolazepam (2 mg/kg) after acepromazine premedication, or a propofol dose of 5 mg/kg. The onset of anesthetic recovery was determined by the animals regaining consciousness and attempting to stand. Semen was collected by electroejaculation and evaluated for volume, pH, sperm concentration, progressive motility, morphology, percentage of live cells and functional membrane integrity. Six anesthetized animals with the acepromazine–tiletamine–zolazepam protocol showed erection, but semen could be collected in only four (40%) attempts. Of the animals anesthetized using propofol, nine showed erection, and the ejaculates were collected in eight (80%) attempts. Furthermore, propofol afforded rapid recovery of animals, and ejaculates with enhanced sperm motility and functional membrane integrity as compared with those collected by the other protocol (P < 0.05). In conclusion, use of propofol for anesthetic restraint of collared peccaries enhanced collection of semen by electroejaculation.     

Improved semen collection method for wild felids: urethral catheterization yields high sperm quality in African lions (Panthera leo)

For wild and domestic felids, electroejaculation (EE) is the most common semen collection method. However, the equipment is expensive, there is a risk of urine contamination and animals usually show strong muscular contraction despite general anesthesia. Accordingly, we tested the feasibility of a different approach using urethral catheterization (UC) in seven African lions, previously described for domestic cats only. After general anesthesia with the α2-agonist medetomidine (which also stimulates semen release into the urethra) and ketamine, a transrectal ultrasound was performed to locate the prostate. A commercial dog urinary catheter (2.6 or 3.3 mm in diameter) was advanced approximately 30 cm into the urethra to allow semen collection into the lumen of the catheter by capillary forces. After retraction, sperm volumes between of 422.86 ± 296.07 μl yielded motility of 88.83 ± 13.27% (mean ± SD) with a mean sperm concentration of 1.94 × 10⁹/ml. Here we describe a simple, field friendly and effective method to attain highly concentrated semen samples with excellent motility in lions and potentially other wild felid species as an alternative to electroejaculation.     

Biochemical and physiological characteristics of semen of sex-reversed female rainbow trout (Oncorhynchus mykiss, Walbaum)

This works studies the biochemical (protein concentration, osmolality, antitrypsin activity, lactate dehydrogenase activity) and physiological characteristics (sperm motility characteristics) of semen of sex-reversed female rainbow trout (n = 42) obtained with the application of 11β-hydroksyandrostendione for sex reversal. All data were arbitrarily divided into three classes depending on the percentage of sperm motility: I XX < 25%; II XX 25-50% and III XX > 50%. The average percentage of sperm motility was 18 ± 7% n = 12 (group I XX); 42 ± 6% n = 15 (group II XX) and 65 ± 12% n = 15 for group III XX, respectively) to link the values of semen parameters to the maturation stage of semen. Semen from 12 normal males of the same age was used as a reference group. Sperm concentration as well as protein concentration, osmolality, antitrypsin activity, and lactate dehydrogenase activity in seminal plasma of sex-reversed females were higher compared with the values obtained for normal male rainbow trout. The values of these parameters declined with the increasing percentage of sperm motility toward values established for normal males. The fertilization success of semen (3 × 10⁶ spermatozoa/egg) of sex-reversed females was very high (above 90%) for both the percentage of eyed embryos and hatched larvae and was related to sperm motility classes. Correlations between the quality parameters of sex-reversed females semen corresponded to those established previously for the semen of normal male rainbow trout. Antitrypsin activity, lactate dehydrogenase, protein concentration, and osmolality were found to be characteristic of seminal plasma of sex-reversed females. The maturity of sex-reversed female spermatozoa seems to be associated with the decline in the values of those parameters toward the values characteristic for seminal plasma of normal males.     

Dynamics of sperm DNA fragmentation in domestic animals: II. The stallion

The mixed success of equine artificial insemination programs using chilled and frozen-thawed semen is most likely associated with the variable response of the sperm cell to the preservation process and the fact that stallions are not selected on the basis of reproductive performance. We propose that the traditional indicators of sperm viability do not fully account for male factor infertility in the stallion and that knowledge of sperm DNA damage in the original semen sample and during semen processing may provide a more informed explanation of an individual stallion's reproductive potential. This study reports on the validation of a sperm DNA fragmentation test based on the sperm chromatin dispersion test (SCD) for stallion spermatozoa and on its application to semen that was chilled (4 °C; n = 10) or frozen-thawed (n = 13). Semen samples were collected by artificial vagina and the proportion of sperm with fragmented DNA determined. Seminal plasma was then removed by centrifugation and the sperm pellet re-suspended in commercial extenders prior to being chilled or cryopreserved using standard industry protocols. Chilled semen was cooled slowly to 4 °C and stored for 1 h before commencing the analysis; cryopreserved semen was thawed and immediately analyzed. Following chilling or cryopreservation, the semen samples were incubated at 37 °C and analyzed for SCD after 0, 4, 6, 24 and 48 h storage. The results of this investigation revealed that there was no significant difference in the sperm DNA fragmentation index (sDFI) of sperm evaluated initially after collection compared to those tested immediately after chilling or cryopreservation. However, within 1 h of incubation at 37 °C, both chilled and frozen-thawed spermatozoa showed a significant increase in the proportion of sDFI; after 6 h the sDFI had increased to over 50% and by 48 h, almost 100% of the sperm showed DNA damage. While the sDFI of individual stallions at equivalent times of incubation was variable, an analysis of the rate of change of sDFI revealed no difference between stallions or the way in which the semen was preserved. In terms of sperm DNA fragmentation dynamics, the highest intensity of sperm DNA damage occurred in the first 6 h of incubation. We suggest that the SCD test can be used as a routine assessment tool for the development and refinement of preservation protocols designed to reduce stallion sperm DNA damage.