Seminal Characteristics Research Articles

Male fattening is related to increased seminal quality of squirrel monkeys (Saimiri collinsi): Implications for sperm competition.

Saimiri are neotropical primates with seasonal reproduction, males develop a seasonal fattening condition that has been suggested as a pre-copulatory sexual selection strategy. Furthermore, females mate with multiple males in the same season. This could also favor the evolution of a postcopulatory sexual strategy by sperm competition. In this study, we tested the hypothesis that there is a relationship between the fatted condition and advantageous seminal characteristics in Saimiri collinsi and evaluated its implications for sperm competition. Adult males (N = 10), aged 5-15 years, housed in mixed or only-male groups, were analyzed from June, 2015 to July, 2016. Measurements of weight, axilla, and arm skinfold, and testicular volume were taken monthly, and semen was collected by electroejaculation. A fattening index was developed to quantify and identify fatted males, biometrics, and seminal parameters were compared between the non-fatted and fatted conditions. The fatted males present a larger testicular volume. This is related to the increase in spermatogenic activity necessary to sustain a high ejaculation frequency during the mating season. An increase in seminal volume and in frequency of semen coagulation were detected in fatted males, advantages related to sperm protection in the female reproductive tract. Age and social context were not significant sources of variation for both morphological and seminal traits. A decrease in response from the fatted males in obtaining semen and an increase in the frequency of azoospermic ejaculates were observed. These unexpected results may be due to intense reproductive activities in a short period. The fattening phenomenon has many implications in the sexual selection of squirrel monkeys, and they are still not entirely unveiled. Our results corroborate the idea that, in S. collinsi, the fatted male condition is related to sexual selection, and we found evidence suggesting it may be also expressed by a post-copulatory component, sperm competition.

Detection of lipid peroxidation in dog spermatozoa with the fluorescent dye C11-BODIPY581/591.

C11-BODIPY581/591 is a fluorescent probe that has been successfully used to evaluate lipid peroxidation in different species, but it has not been completely studied in the dog. Thus, the aim of the present study was to assess lipid peroxidation of dog spermatozoa using C11-BODIPY581/591 and compare different positive controls of the technique. Twenty-four ejaculates were collected from 8 adult male dogs. Routine seminal characteristics were evaluated in raw semen. Lipid peroxidation evaluation was performed as described in other species. Samples were divided in three aliquots, exposed to UV radiation, incubated with hydrogen peroxide or left without treatment (control). Lipid peroxidation was significantly greater only in UV-exposed samples than in the control ones (91±6% vs. 8.3±3.5%, p˂.01). In conclusion, C11-BODIPY581/591 is useful to evaluate lipid peroxidation of dog spermatozoa and UV radiation is a good promoter of membrane oxidation, so irradiated samples can be used as a positive control of this technique.

Semen quality, testosterone values, and testicular and accessory gland parameters in rams receiving sustained stimulation with low doses of buserelin

Context The use of buserelin, a gonadotropin-releasing hormone (GnRH) agonist, can improve semen quality. Nevertheless, the appropriate dosage, and frequency and time of application, remain to be established owing to the subsequent negative feedback on endogenous production of testosterone described so far. Aims This study aimed to propose a new buserelin application protocol for sperm improvement in Santa Inês rams. Methods Fifteen Santa Inês rams were divided into two experimental groups: the first group (n = 8) received 2.5 μg buserelin acetate; and the second group (n = 7) received saline solution. Treatments were applied for 21 days at intervals of 6 h, totalling four hormonal or saline applications per day. In all animals, macroscopic and microscopic seminal characteristics and freezability, plasma testosterone, pixels of testicular parenchyma, and biometric analysis of testicular and accessory sex glands by ultrasound were evaluated throughout the period of hormonal application and for a further 7 days. Key results Rams receiving buserelin showed a peak of testosterone after the first week (Day 7) of application, with a drop in values at Day 14, followed by negative feedback at Day 21 and return to basal concentrations at Day 28. They also showed improvement of kinetics parameters such as straight line velocity (μm/s: +buserelin 51.5 ± 1.5 > control 46.6 ± 1.6) and linearity coefficient (%: +buserelin 53.5 ± 1.8 > control 47.5 ± 1.9). Ultrasound parameters, pixels of testicular parenchyma, and freezability were not affected by treatment. Conclusions The administration of buserelin was able to improve some sperm kinetics parameters of Santa Inês rams. Implications Low doses of this GnRH analogue can be used; however, further adjustments to the hormonal protocol are needed to obtain an effective improvement in sperm quality.

Reproductive Management of the Male Goat: A Review

Objective: To describe the factors affecting male goat (buck) reproduction and the selection and management strategies to improve their reproductive efficiency. Design/Methodology/Approach: By reviewing published information, the main factors that affect the reproductive capacity of bucks and some management strategies for their reduction were described. Emphasis was on the evaluation of seminal quality, libido, and the selection of sires to be used in the herd. Results: Proper sire diet reduces age at puberty and improves testicular and seminal characteristics, as well as sexual behavior. The effect of seasonality can be improved by using melatonin implants and adequate nutrition. Study Limitations/Implications: In goat production systems, bucks are important for the production of quality livestock and the products and byproducts from this species. Understanding the impact of environmental factors such as nutrition, seasonality, and physiological processes on the reproductive capacity of bucks promotes the establishment of management strategies to better understand what is important when selecting sires as sperm donors to improve product quality and to obtain greater herd production. Findings/Conclusions: Adequate sire nutrition improves herd fertility. Seasonal reproduction affects the reproductive capacity of sires as sperm donors, yet there are management alternatives to reduce such seasonal effects on their reproductive performance.

Evaluation of seminal characteristics of Pelibuey and East Friesian rams at two different times of the year

Objective: To determine the changes in seminal quality of Pelibuey and East Friesian rams during the non-breeding (long days; March-June) and breeding seasons (short days; September-December) at 19° north latitude. Design/methodology/approach: To determine changes in seminal quality over time, seminal parameters of rams, collected with an artificial vagina were evaluated over 32 weeks. An analysis of variance was performed with a completely randomized design in a 2 x 2 factorial arrangement (breed and season). Results: No differences were found within breeds or between breeds in the same season in the evaluated seminal parameters; however, differences were reported between seasons in the live weight parameters, lower in the non-reproductive season, in addition to an increased scrotal circumference and mass motility during the reproductive season. Study limitations/implications: Semen parameters estimation, in field trials, is subjective compared to computerized semen evaluation systems, it is therefore desirable to have extensive experience in semen evaluation at the field level before starting the study. To confirm the results obtained in this study, a new experiment with a larger number of experimental units is suggested. Findings/conclusions: It is concluded that in the environmental and management conditions, where the seminal evaluation took place, no differences were found between breeds, suggesting that the Pelibuey and East Friesian breeds at 19° north latitude do not decrease their seminal parameters during the non-breeding season compared to the breeding season. This suggest that these two sheep breeds are able to reproduce, in such conditions, all year round.

Scrotal thermographic profile and seminal characteristics of Mangalarga Marchador stallions bred in the Atlantic Rainforest biome

ABSTRACT The objective of this study was to determine the scrotal thermographic profile and to verify the influence of temperature and humidity of the humid tropical climate on testicular temperature and seminal quality of Mangalarga Marchador stallions. The thermal profiles of the proximal, middle, and distal zones of the testicles and total surface temperature (TSTT) were recorded using an FLIR E60bx thermal imager. The average air temperature (°C) and relative humidity (%) were obtained 1, 5, 9, 33, and 66 days before semen collection and showed a mean value of 26.5±2.4 and 80.4±6.0 respectively. The scrotal surface temperature was close to 34°C and there was no variation with the age of the stallion, reproductive activity, and characteristics of the ejaculate (P>0.05). The only significant correlations obtained were between TSTT and minor defects (R = 0.41; P<0.05), between TSTT and total defects (R = 0.46; P<0.01), and between TSTT and percentage of morphologically normal sperm (R = -0.46; P<0.05). It was concluded that the Mangalarga Marchador stallions maintained the testicular temperature within favorable conditions for spermatogenesis, demonstrating the efficiency of testicular thermoregulation mechanisms in the Atlantic Forest biome.

Seminal plasma insulin-like growth factor I and total protein concentration in peripubertal period of the Gyr bulls.

This study aimed to evaluate the correlation of seminal plasma IGF-I and total proteins from peripubertal bulls with semen characteristics and onset of puberty. Sixteen dairy Gyr bulls were separated into early (n=8) and regular (n=8) groups, according to the onset of puberty. Semen was monthly collected by electroejaculation from 14 to 26months of age, and the onset of puberty was retrospectively determined (17.0±1.6 and 19.2±1.5months, to early and regular group, respectively). Five time points were evaluated (day -60, day -30, day 0, day 30 and day 60days of puberty), being day 0 considered as beginning of puberty. Scrotal circumference and body weight were also assessed. Semen characteristics were evaluated, the seminal plasma was separated by centrifugation and total protein and IGF-I concentrations were determined. There was no difference between groups to concentration of the seminal plasma total proteins, but we found an interaction between group and age. Seminal plasma IGF-I concentrations were not different between early and regular groups; thus, the data were combined for analysis. Combined IGF-I concentrations were positively correlated with sperm motility and concentration, age, body weight and scrotal circumference. Negative correlation was found between IGF-I concentration and total sperm defects. Increased IGF-I was observed in day -30 and day 0 of puberty in early and regular groups, respectively. Seminal plasma total proteins are involved in peripubertal modifications and IGF-I from Zebus dairy bulls can influence the seminal characteristics and the growth factor increase occurs concomitantly with body growth but cannot be used to define puberty bulls earlier.

Efficiency of the anti-GnRH vaccine for castration of lambs intended for finishing in pastures

It was aimed to evaluate anti-GnRH vaccine efficiency on productive characteristics, seminal performance, size, and histology of testicles of lambs submitted to immunocastration. Twenty contemporary Texel lambs were evaluated, being 10 animals received two doses of 1 mL of anti-GnRH vaccine and 10 received two doses of 1 mL of saline, with an interval of 30 days. Seminal characteristics, weight and histological cut for the testicles, productive performance, and blood parameters were analyzed. Andrological monitoring was carried out every 30 days. All animals were kept on pasture of Urochloa spp. receiving daily supplementation protein-energetic by 90 days. There was effect of immunocastration on slaughter weight (44.3 vs. 48.3 kg), total gain (9.9 vs. 10.3 kg), daily gain (104.5 vs. 108.9 g/day), and feed conversion (5.83 vs. 5.97) respectively to immunocastrated and intact lambs. There was immunocastration effect on testicle weight (0.09 vs. 0.35 g), motility (4.5 vs. 61.0%), vigor (0.40 vs. 3.00), volume (0.09 vs. 0.74 mL) and swirling (0.20 vs. 2.70) in the third semen collection. Immunocastration through two doses of 1 mL of anti-GnRH vaccine with a 30-day interval between doses, causes infertility in sheep and can be adopted for lambs.

Using transrectal ultrasound-guided massage of the accessory sex glands for buck semen collection yields semen with greater cryoresistance than electroejaculation alone during the breeding season

The cryoresistance of bucks’ semen collected by transrectal ultrasound-guided massage of the accessory sex glands (TUMASG) and electroejaculation (EE) was compared during the breeding season (Study 1) or the late non-breeding season (Study 2). Semen was collected from 10 Gabon bucks with both methods in each season and then frozen according to a standardized protocol. The time required for ejaculation, the number of electrical pulses applied, the sum of the electrical pulses applied∗voltage and the total number of vocalizations emitted during the collection by each animal were recorded. In Study 1, TUMASG required a longer time (P = 0.0006) but fewer electrical pulses and a lower sum of pulses∗voltage than EE (P < 0.0001 for both comparisons). Bucks vocalized fewer times during TUMASG than during EE (P < 0001). Semen collected with TUMASG had greater sperm concentration, sperm mass motility, total number of motile sperm and of sperm with progressive motility, and tended to have greater total number of sperm with functional membrane than semen collected with EE (P = 0.02; P = 0.003; P = 0.02; P = 0.02; P = 0.06, respectively). After the freezing-thawing process, sperm collected with TUMASG had a greater quality of the motility, a total number of motile sperm and sperm with progressive motility, a greater percentage of motile sperm and sperm with functional membrane, and tended to have a greater total number of sperm with normal morphology than semen collected with EE (P = 0.04; P = 0.04; P = 0.03; P = 0.02; P = 0.04; P = 0.06, respectively). In Study 1 sperm collected with TUMASG had greater cryoresistance for almost all the variables considered than when it was collected with EE. In Study 2, the number of electrical pulses and the sum of pulses∗voltage were greater with EE than with TUMASG (P < 0001; P = 0.0002, respectively). There were no differences in any sperm variable in fresh or thawed samples collected with TUMASG or EE. However, the other seminal characteristics evaluated did not differ according to the method, and there were no differences in the cryoresistance of any variable. Overall, TUMASG affected animal welfare less than EE and was suitable for collecting semen of good quality with high cryoresistance during the breeding season in buck.

Evaluation of potential reproductive seasonality in brown brocket deer (Mazama gouazoubira) bucks

Photoperiod is the main cue that controls seasonal reproduction in deer from temperate regions, like secretion of testosterone by the testis, neck enlargement, and testis development. However, little is known about its effect on the reproduction of tropical deer species. This research aimed to assess the potential seasonality of the brown brocket deer (Mazama gouazoubira) by melatonin treatment. Reproductive parameters such as testicular volume, neck circumference, and semen quality were evaluated from day 0 to 90, and fecal androgen metabolites (FAM) from day −28 to 91. Melatonin treatment was administered from day 0 to 60. In total, seven individuals were used in the study. Four animals were allocated to the treated group (TG) and three to the control group (CG). The neck circumference and some seminal parameters did not show a significant difference between CG and TG and along the experimental period. High FAM levels were observed for the TG on days 7, 14, 21, 35, 84, and 91 (p < 0.05). The mean testicular volume was reduced from day 0 to 30 (p < 0.05) and from day 0 to 90 (p < 0.05), with no increase in the mean testicular volume from day 30 to 60 (p > 0.05). Sperm motility was the highest on day 60 compared with day 0 (p < 0.05). Although not statistically different, membrane integrity and major defects tended to be higher and lower, respectively, in the TG compared with the CG. For these parameters, the incremental change (%) per individual showed that males from the TG tended to have a higher percentage during the melatonin treatment, hence melatonin might affect these seminal characteristics. These findings suggest that exogenous melatonin might enhance FAM levels and sperm motility.

Analysis of the Functional Aspects of Sperm and Testicular Oxidative Stress in Individuals Undergoing Metabolic Surgery.

Metabolic surgery is a recommended treatment for obese patients that results in BMI reduction; however, the observed impact of this therapy on male fertility is inconsistent. This research aimed to study the effects of BMI changes after metabolic surgery on seminal analysis, sex hormonal profile, sperm functional integrity, and the seminal plasma lipid peroxidation levels. A prospective study was performed in 15 patients for whom metabolic surgery was recommended. The patients were evaluated by the techniques proposed in this study before and after the surgical procedure for 12 months. In each analysis, the male sex hormonal profile, semen analysis, sperm functional integrity, and seminal lipid peroxidation levels were assessed. The surgery resulted in BMI reduction and improvement in seminal characteristics and male sex hormone profile. The semen analysis showed increases in volume, sperm progressive motility, and in sperm morphology and a decrease in immotile sperms. Sperm mitochondrial activity and sperm DNA integrity were improved, and the levels of seminal lipid peroxidation were decreased. The hormonal profile showed lower levels of estradiol and highest levels of luteinizing hormone (LH), sex hormone-binding globulin (SHBG), and testosterone. BMI changes resulting from this treatment and its metabolic consequences can be associated with changes in the male fertile potential, leading to an improvement in the seminal quality, male sex hormone profile, sperm functional aspects, and levels of seminal lipid peroxidation, thus decreasing the testicular oxidative stress.

Improving seminal quality and reproductive performance in male broiler breeder by supplementation of camphor

The current study was conducted to evaluate the effect of dietary camphor levels as a medicinal feed additive to improve semen quality, antioxidant capacity, reproductive hormones, and reproduction performance in roosters. For this purpose, thirty-five 29-wk-old Ross 308 broiler breeder roosters randomly were assigned to five experimental groups (seven birds/group) and received five doses of camphor containing 0, 50, 250, 750, and 1000 mg camphor/kg of feed for 12 wk consecutive. Semen quality parameters and motion characteristics of sperm were evaluated every 28 days and semen antioxidant capacity and plasma reproductive hormones concentration were tested at the end of the experiment. Also, at the end of the experiment, reproductive performance was assessed using artificial insemination. Among seminal quality parameters, sperm forward motility (88.96 vs 82.56%) and percentage of abnormal sperm (14.75 vs 15.86%) were improved in roosters fed 50 mg camphor/kg of feed compared to the control group (P < 0.05). Overall percentage of live sperm and plasma membrane integrity exhibited the quadratic responses to the levels of camphor (P < 0.08). The motion characteristics of sperm including progressive motility (28.81 vs 21.77%), average path velocity (VAP, 33.35 vs 26.83 μm/s), progressive velocity (VSL, 19.78 vs 16.48 μm/s), curvilinear line velocity (VCL, 52.87 vs 44.38 μm/s), the amplitude of lateral head displacement (ALH, 2.92 vs 2.46 μm) were improved in roosters fed 50 mg camphor/kg of feed compared to the control group (P < 0.05). However, dietary camphor levels linearly increased the percentage of linearity (LIN) and straightness (STR) (P < 0.05). A significant decrease in seminal plasma concentration of malondialdehyde (MDA) and an increase in superoxide dismutase (SOD) activity were observed in birds fed 1000 mg camphor/kg of feed (P < 0.05). Testosterone concentration was considerably increased by doses of 50 and 250 mg camphor/kg of feed compared to control (4.68, 4.79 vs 3.88 ng/mL) (P < 0.05). FSH and LH concentrations were not affected by camphor supplementation (P > 0.05). In the artificial insemination, fertility rate from both 50 mg camphor/kg of feed (88%) and 250 mg camphor/kg of feed (84%) was higher than control (75%) (P < 0.05). In conclusion, low levels of camphor, especially 50 mg camphor/kg of feed, improved seminal characteristics and, reproductive performance of roosters. Further researches are needed on the effect of higher levels of camphor and divulge of underlying mechanism on male’s reproductive function.

Correlation between the DNA fragmentation index (DFI) and sperm morphology of infertile patients

PurposeTo evaluate the correlation between the DNA Fragmentation Index (DFI) and sperm morphology in patients undergoing ICSI, as a predictive parameter in reproductive outcomes.MethodsA retrospective study was conducted on 125 infertile patients enrolled in a fertility clinic. Seminal characteristics were measured following the WHO guidelines (2010) for the examination of the seminal fluid. After collecting motile sperm population by pellet swim up, DFI was calculated and simultaneously associated with sperm morphology using in situ TUNEL assay and an image analyzer software in at least 250 spermatozoa for each patient.ResultsAll subjects were divided into two groups according to a cutoff established, by choice, of the sperm DFI (15%): group A (< 15%) consisting of 65 patients and group B (≥ 15%) of 60 patients. Data were analyzed using non-parametric statistical methods. The results demonstrate that there is no statistical difference between the two groups in seminal characteristics. The collective data show a high significant correlation, suggesting that spermatozoa with abnormal morphology are the best candidates to contain DNA damage (p < 0.001). Also, when group A is compared with group B, an increased percentage of morphologically normal spermatozoa with fragmented DNA was observed in patients, with DFI values ≥ 15% (p < 0.001).ConclusionThese results are aimed at providing an exact value of DFI in morphologically normal spermatozoa, which will be helpful to the embryologist in evaluating the risk of transferring, during the ICSI procedure, a spermatozoon whit normal morphology but fragmented DNA.

PRELIMINARY OBSERVATIONS ON THE SEMINAL CHARACTERISTICS OF RABBITS RAISED IN TWO LOCATIONS IN SOUTHEASTERN NIGERIA.

A total of sixteen rabbits sourced from two locations in Southeastern Nigeria were used for this study. Semen was collected from all the rabbits twice weekly for eight weeks using an artificial vagina while observation on the effect of time of collection on semen quality were also made. The results obtained indicated that time of collection had no significant effect (P &gt; 0.05) on all the seminal characteristics measured. However, source of the animals showed significant effect (P &lt; 0.05) on semen volume, sperm concentration, total sperm per ejaculate and proportion of abnormal sperm. Average semen volume, sperm concentration and total sperm per ejaculate were: 0.69±0.007 ml, 104.0±1.44 x 106/m1 and 71.40±0.90x106 respectively for the rabbits sourced from Port Harcourt. The corresponding values for rabbits sourced from Owerri were: 0.66±0.008m1, 96.02 ±1.63x106iml and 63.49±1.50 x 106 respectively. Abnormal sperm proportions were 11.05±0.22% and 1216 ± 032% for the rabbits sourced from Port Harcourt and Owerri respectively. There were no significant (P&gt; 0.05) differences observed between locations in live sperm concentration and sperm motility. Live sperm concentration and sperm motility were 87.75±1.09% and 71.62±0.74% for the Port Harcourt group, while the values obtained for the Owerri group were 88.06±034% and 71.19±0.89% respectively.&#x0D;

Semen Characteristics of First and Second Ejaculates of Buffalo Bulls With and Without Sexual Stimulation

Four treatments, no sexual preparation (control), 10 min restraint, three false mounts and 10 min restraint followed by three false mounts, were replicated with eight sexually mature buffalo bulls, before the first and second ejaculates to study their effects on the seminal characteristics of buffalo bulls. Seminal characteristics of both first and second ejaculates were improved significantly by sexual stimulation. Animals allowed no sexual stimulation yielded inferior first ejaculates than second ejaculates in all seminal characteristics. First ejaculates, in this case, served as stimulus to second ejaculates and contributed to its superiority. Moderate sexual stimulation (R or FM) before ejaculation improved the first ejaculates and reduced the difference between them and second ejaculates in all seminal characteristics. However, high degrees of sexual stimulation (R or FM) caused the superiority of the first ejaculates to the second ejaculates in seminal characteristics.

Influence of garlic (Allium sativum) and vitamin E on semen characteristics, reproductive performance and histopathology of rabbit bucks

Researches have proven that garlic has medicinal, antimicrobial properties, speeds up digestion and widely used as preservatives, spice and condiment in many homes Vitamin E on the hand is a fat soluble vitamin with potent antioxidant properties essential for the stabilization of biological membranes, protecting cells from oxidative stress and inhibits angiogenesis. Thus, a study using thirty-six (36) pre-pubertal New Zealand White rabbit bucks was conducted to investigate the physiological response of garlic and vitamin E supplementations on libido, gonadal and extra-gonadal sperm characteristics, reproductive hormone and testicular histology of rabbit bucks. The bucks were randomly assigned to four dietary treatments and replicated three times in a completely randomized design (CRD). Each dietary treatment consisted of 9 rabbits per treatment with 3 rabbits per replicate. Four dietary treatments were formulated to meet the nutrient requirements of rabbits supplemented at 0% garlic and vitamin E (T1), 3% garlic (T2), Vitamin E (T3), and 3% garlic and Vitamin E (T4) respectively. Data were collected on the libido, seminal characteristics, seminal plasma, testicular morphology and hormones. The testicles were collected and processed for histopathology. Data collected on different parameters were subjected to analysis of variance (ANOVA). Results showed that significantly (P&lt;0.05) differences were observed in all the seminal characteristics parameters, on the testicular weights, volumes and on the reproductive hormones compared with the control. Testicular histology showed increased in number of seminiferous tubules with the supplementation. These results proved that both garlic and Vitamin E improve semen production both in quality and quantity and the overall reproductive performance. Moreover, combination of the garlic and vitamin E gives a better result. Therefore, garlic and vitamin E should be used together for better quantitative and qualitative semen production and reproductive performance in breeding animals

PSX-24 Seminal characteristics or Dorper rams with different social hierarchies in northern Mexico

Abstract The aim of this study was to evaluate the possible difference in seminal characteristics of Dorper rams of either high, medium or low social ranks in northern Mexico (26º N). The male’s social status was quantified through a competitive behavioral test in a herd of 36 adult males, the aggressive interactions and their consequences were registered to calculate the success index (SI), where low hierarchy (LH) rams had a SI of 0 to 0.33, medium hierarchy (MH) rams had a SI of 0.34 to 0.66 and high hierarchy (HH) had a SI of 0.67 to 1. Afterwards, the rams were subjected to an estrogenized female (2 mg of estradiol cypionate) for teasing in order to collect a semen sample with an artificial vagina. The semen was evaluated for volume, motility and concentration. The seminal characteristics differences were analyzed using a one-way ANOVA tests and stablishing a p-value of 0.10 as significance level in the SPSS statistical package. Results are shown in table 1. In conclusion, low hierarchy Dorper rams show a statistical tendency to have a lower sperm concentration.

Detrimental effects of long-term exposure to heavy metals on histology, size and trace elements of testes and sperm parameters in Kermani Sheep

Exposure to endocrine-disrupting chemicals (EDCs) has been hypothesized as a cause of declining sheep reproductive efficiency. Understanding the long-term effects of EDCs such as heavy metals on reproductive health requires investigation in 'real life' of sheep that are reared in industrial areas. The aim of this study was to evaluate the effect of long-term exposure of Kermani rams to high levels of environmental heavy metals probably emitted from a copper smelter at KhatoonAbad in ShahreBabak, Kerman province. Testicular characteristics were determined in randomly-selected rams (3–4 years old) at 4 directions (south, north, east, and west) and 4 distances (10, 20, 30, and 40 km) from the smelter. Testicular trace element contents, size, serum testosterone, histological attributes and seminal characteristics, except semen volume, were affected by both the direction and the distance from the smelter (P < 0.05). Testicular contents of Pb, Cd, Cr, and Ni, and sperm abnormalities were higher at 10 km south from the smelter and lower at 40 km west. Other parameters were higher at 40 km west and lower at 10 km south. Interestingly, the testicular contents of Cu at 10 km south were lower and associated with higher sperm abnormalities in the rams reared closer to the smelter. The highest weight, length and circumference of the testis were found at 40 km west. The lowest concentration of testosterone was observed at 10 km south, being 92.6% lower than the highest values obtained at 40 km west. The diameter of seminiferous tubules and epithelial height at 10 km south were 8.9% and 27.5% lower than the highest values obtained at 40 km west. A positive correlation between Pb, Cd, Cr and Ni contents in the testis with sperm abnormalities, and a negative correlation between these elements with the other parameters were found. It was concluded that long-term exposure to heavy metals might have been a cause of decreased fertility in rams and probably other living species in this region.

Effect of season on individual stallion semen characteristics

Horses are long-day seasonal breeding animals, however, with modern stallion reproductive management it is important for collection of semen during periods that are not part of the traditional breeding season. This study was conducted to examine variation in the seminal characteristics of individual stallions in Avila, Spain during 1 year with a particular emphasis on sperm DNA fragmentation. Semen was collected twice per season from a total of 20 stallions. There was a marked seasonal effect on all seminal characteristics, with the greatest on progressive motility, % membrane integrity and least for SDF in the spring months; there was also an interaction effect with respect to individual stallion, indicating that some stallions did not fit this generalised pattern for semen quality. Sperm DNA fragmentation was assessed both immediately after semen collection (T0) and following incubation of extended semen for 24 h (T24) to broadly mimic changes in SDF that might occur in the female reproductive tract. While SDF evaluated at T0 was also generally less in spring, the proportion of stallions with the least SDF values in spring increased from 45% to 60% when assessed at T24, therefore, being consistent with the importance of dynamic SDF assessment in detecting DNA damage that was not detected at T0 or cryptic DNA damage. The results from this study indicate there is individual seasonal variation among stallions in all aspects of seminal characteristics; such variation needs to be considered when prioritising stallions that are to be used for breeding.

Manual Collection and Semen Characterization in a West Indian Manatee (Trichechus manatus).

Limited information is available regarding male reproductive physiology in West Indian manatees (Trichechus manatus). Currently, only basic ultrastructural and morphometric descriptions of the spermatozoon exist; however, there are no reports evaluating any seminal characteristics in this species. Therefore, the aim of the study was to fill current gaps in knowledge regarding semen parameters in West Indian manatees by collecting and characterizing multiple ejaculate samples from a single, adult West Indian manatee. Samples were analyzed for the following semen parameters: volume, agglutination, pH, osmolality, viscosity, concentration, total sperm number, motility and kinematic parameters, morphology, plasma membrane integrity, acrosome integrity, chromatin maturation, and chromatin condensation. All macroscopic semen parameters varied to some extent between samples. Total and progressive motility was high for ejaculates 2 to 5, exceeding 97 and 89%, respectively; however, these parameters decreased dramatically throughout ejaculates 6 and 7. Across all samples, curvilinear velocity, straight-line velocity, and average pathway velocity represented the largest significant differences (p < 0.001) between each of the progression velocity subgroups (rapid, medium, slow). Sperm characteristics, including acrosome integrity (79.8%), chromatin condensation (93.1%), and chromatin maturation (99.5%) were very high; however, high numbers of morphologically abnormal sperm were present (52.9%) and plasma membrane integrity was low (45.1%). These results are the first of their kind for this species and suggest high semen quality, based on multiple ejaculates, in this male West Indian manatee.