Male condition and seminal fluid affect female host-marking behavior in the Mexican fruit fly.

Mating and the transfer of seminal fluid components including male accessory glands (MAGs) proteins can affect oviposition behavior in insects. After oviposition, some species of fruit flies deposit a host-marking pheromone (HMP) on the fruit that discourages oviposition by other females of the same or different species or genus and reduces competition between larvae. However, we know very little about how mating, receiving seminal fluid, or male condition can affect female host marking behavior. Here, we tested how the physiological state of females (mated or unmated), the receipt of seminal fluid, and the condition of the male (wild or sterile) affect oviposition and host-marking behavior (HMB) in Anastrepha ludens (Diptera: Tephritidae). We also determined the efficiency of the host-marking pheromone from mated or unmated females in deterring oviposition. In a further examination of how seminal fluid may be affecting HMB we assessed if there were differences in the size of wild or sterile MAGs and the protein quantity transferred during mating. Our results indicate that receiving seminal fluid increased egg laying and increased time invested in host-marking (HM). Unmated females laid fewer eggs than mated females but invested the same amount of time in depositing host-marking pheromone, which had similar effectiveness in deterring oviposition as that of mated females. Females that mated with sterile males laid the same number of eggs as females that mated with wild males but spent less time depositing host-marking pheromone, which suggests that females detect the condition of the male and invest less in marking hosts. Finally, sterile males had larger accessory glands and transferred more MAGs proteins during mating compared to wild males. Seminal proteins could be manipulating HM behavior and female investment into their current reproductive effort. We are only beginning to understand how male condition and seminal fluid can affect female physiology and maternal investment in HMP.

Seasonal seminal quality variations and vitrification prospects in black flounder Paralichthys orbignyanus.

Long-term preservation of gametes has been identified as a tool to improve broodstock management and increase the number of juveniles produced by artificial fertilization. Paralichthys orbignyanus is an important commercial and recreational species distributed in marine and estuarine waters from Rio de Janeiro (Brazil) to the San Matías Gulf (Argentina). This work focused on studying the seminal quality of tank-reared P. orbignyanus, demonstrating that males are fluent year-round, with the highest yields at the early reproductive season. Fresh sperm exhibited good forward swimming, and samples could be refrigerated up to 48 h while retaining their motility after activation. The optimal conditions for P. orbignyanus sperm motility activation were established as 950 mOsmol/Kg and pH values between 7 and 7.9. Additionally, a well-defined protocol for semen vitrification was developed to assess the cryotolerance of this species' sperm. We successfully produced high-quality sperm samples, using two vitrification formulations containing trehalose and both z-1000 and x-1000 polymers, that can be used in a near-future in vitro embryo production program.

Inclusion of cocoa bran in the diet of lambs and its effect on reproductive parameters.

The objective of the study was to evaluate the effect of the inclusion of cocoa bran in the diet of lambs and its effect on reproductive parameters. For this, 40 lambs were randomly assigned to four treatments, and including 0, 10, 20 and 30% levels of cocoa bran in the concentrate. Blood was collected to measure cholesterol and testosterone and semen for physical and morphological evaluation; testicular biometry and morphometry were also evaluated. There was significant difference (P < 0.05) in body weight and tubulosomatic index between the lambs in the control treatment and those in the 30% cocoa bran treatment. There was no difference in testicular biometry, physical and morphological parameters of fresh semen, testicular morphometry, and volumetric ratio between lambs in all the treatments (P < 0.05). In addition, there was no difference in plasma cholesterol or testosterone concentration (P > 0.05). Thus, it is possible to include up to 30% of cocoa bran in diet without affecting the reproductive parameters of lambs.

Impact of heat waves on semen quality: A retrospective study in Argentina between 2005 and 2023.

Heat waves, defined as periods with daily temperatures surpassing the historical average for a specific region, have become more frequent worldwide in recent years. Previous studies have reported a negative association between temperature and semen quality, but the focus has mainly been on Asian and European populations. The study included 54,926 men (18-60 years) undergoing routine semen analysis between 2005 and 2023 at CEUSA-LAEH andrology unit, in Buenos Aires, Argentina. Hourly temperature readings were provided by the Servicio Meteorológico Nacional. R programming (R Studio v2022.07.2) was used to define heat waves, calculate key characteristics, visualize results, and perform statistical tests at the IBYME laboratory. During the period studied, a total of 124 days had heat waves (defined after at least 3 consecutive days with 32.3 °C and 22 °C). Men exposed to heat waves during spermatogenesis exhibited lower sperm number (concentration and count; P < 0.0001) and decreased normal morphology (percentage of normal sperm and normal motile count; P < 0.05) compared to those not exposed. These differences were most pronounced between semen samples from years with several heat waves (2013, 2023) and none (2005, 2007, 2016), displaying 4-5 times higher fold changes (P < 0.05). Further analysis employing multiple regression revealed a significantly negative association between semen quality and heat wave length, suggesting that a prolonged exposure may be more detrimental than an acute exposure. Subsequent analysis focusing on prolonged exposure (≥6-days heat wave) during spermatogenesis revealed a negative (P < 0.05) association between early exposure (spermatocytogenesis: 64-90 days prior semen collection) and semen quality. This study underscores the negative association between early exposure to heat waves during sperm development and semen quality, raising concerns about its possible association with the worldwide declining male fertility. A comprehensive collaborative approach is crucial, involving global governmental policies, sustainable practices, and coordinated efforts across scientific, healthcare, and policy domains.

Post-cooling semen processing and sperm re-suspension as an alternative method to circumvent poor semen cooling in stallions.

BACKGROUND: Artificial insemination with cooled-shipped semen is the primary method used in the equine breeding industry; yet, sperm quality and fertility can be suboptimal for some stallions when standard techniques are used. Therefore, there is a critical need to develop alternative approaches for these stallions. OBJECTIVE: To assess sperm quality parameters and fertility of cooled-stored stallion semen processed by SpermFilter® or centrifugation and resuspended in three extenders. STUDY DESIGN: Controlled and field study. METHODS: In Experiment 1, semen was collected from 21 stallions classified as having good ('Good-coolers', n = 8) or poor ('Bad-coolers', n = 13) semen cooling. The semen was extended at 30 million spermatozoa/mL in a skimmed milk-based (SM) diluent, and refrigerated for 24 h. Then, the cooled-stored semen was processed through SpermFilter® or centrifugation, and the resulting sperm pellets were resuspended in SM, SM containing pentoxifylline (SM-P), or an egg yolk-based (EY) extender. Unprocessed cooled-stored semen served as control. Sperm motility parameters, plasma membrane integrity (PMI), and mitochondrial membrane potential (HMMP) were assessed in cooled-semen pre- and post-processing. Experiment 2, cooled semen from 9 stallions classified as Bad-coolers was used to inseminate 18 embryo donor mares at 66 cycles (Unprocessed, n = 22; SpermFilter®/SM-P, n = 16; or SpermFilter®/EY, n = 28). Data were analysed with a mixed model and Tukey's as posthoc, and logistic regression. RESULTS: Processed semen resuspended in EY had superior sperm motility compared to unprocessed, SM and SM-P (p < 0.0001). Semen processed by SpermFilter® resuspended in SM-P was similar to EY (p > 0.05). Pellet resuspension with EY and SM-P improved the HMMP of Bad-cooler stallions (p = 0.0010). Semen processed by SpermFilter® had superior PMI to centrifuged semen (p < 0.0001). Mares inseminated with SpermFilter®/SM-P (50%, 8/16) or SpermFilter®/-EY (68%, 9/28) had higher pregnancy rates than mares bred with unprocessed semen (14%, 3/22) (p < 0.001). MAIN LIMITATIONS: Low number of mares in the fertility trial. CONCLUSION: Sperm quality and fertility of Bad-cooler stallions can be enhanced by SpermFilter® and pellet resuspension with either EY or SM-P.

Use of thermography in the long-term evaluation of scrotal surface temperature and its impact on seminal quality in stallions.

Scrotal surface thermography is a non-invasive method for assessing testicular thermoregulation in stallions; however, few studies have explored the application of this technique concerning the thermal physiology of equine reproductive systems. This study aimed to evaluate the consistency of testicular thermoregulation in stallions over a year using thermography to measure the scrotal surface temperature (SST). Moreover, we assessed the best region for measuring the surface body temperature compared with the SST. Ten light-breed stallions were used in the experiment. Thermographic images of the scrotal and body surfaces (neck and abdomen) were captured. Fresh, cooled and frozen-thawed semen samples were evaluated to verify the impact of thermoregulation on semen quality. Testicular thermoregulation was maintained throughout the year in stallions amidst changes in the external temperature, as evidenced by the weak correlation between the SST and ambient temperature. A lower correlation was observed between the environmental temperature and body surface temperature (BTS) obtained from the abdomen (BTS-A; R = .4772; p < .0001) than with that obtained from the neck (BTS-N; R = .7259; p < .0001). Moreover, both BTS-A and SST were simultaneously captured in a single image. The consistent quality of the fresh, cooled and frozen semen suggests efficient thermoregulation in stallions throughout the year.

Sperm traits and seminal plasma proteome of locally adapted hairy rams subjected to intermittent scrotal insulation.

The present study evaluated the effects of heat stress on reproductive parameters of hairy rams. Six animals were subjected to scrotal insulation during four consecutive nights (6 PM - 6 AM). Day (D) 0 was the first day of insulation. Scrotal circumference increased from 30.5 ± 0.3 cm (at pre-insulation) to 31.8 ± 0.4 cm on D4, decreased 3.9 cm on D28, returning to 30.6 ± 0.6 cm on D57. Sperm concentration decreased from 3.7 ± 0.12 ×109 sperm/mL before insulation to 2.6 ± 0.1 ×109 on D23, returning to normal on D57. Sperm motility averaged 75 ± 2.9% before insulation, was undetectable on D23, and became normal on D77. Sperm with normal morphology reached 5.9 ± 2.6% on D35 but recovered (86.8 ± 2.1%) on D91. Sperm DNA integrity decreased from 86.5 ± 4.7% before insulation to 11.1 ± 3.7% on D63, returning to pre-insulation values on D120. Sperm BSP immunostaining was reduced after scrotal insulation. Variations in seminal protein abundances coincided with changes in sperm parameters. Seminal plasma superoxide dismutase, carboxypeptidase Q-precursor and NPC intracellular cholesterol transporter 2 decreased on D18, returning to normal after D28. Albumin, inhibitor of carbonic anhydrase precursor, EGF-like repeat and discoid I-like domain-containing protein 3 and polymeric immunoglobulin receptor increased after insulation. In summary, intermittent scrotal insulation drastically altered ram sperm attributes and seminal proteins, especially those associated with oxidative stress. Knowledge of animal´s response to thermal stress is vital in the scenario of climate changes.

Seasonal heat stress compromises testicular thermoregulation and semen quality of Dorper rams raised in a desert climate.

Dorper rams are widely distributed throughout the world under different climatic conditions, however, little is known about their reproductive performance in desert regions. Ten Dorper rams were individually housed and exposed to thermoneutrality for 35 d in spring (23.6 ± 5.6 °C, mean ± SD) and outdoor heat stress (HS) for 35 d in summer (33.6 ± 2.0 °C) to evaluate the effect of seasonal HS on physiological responses, testicular biometry, and seminal quality under desert climatic conditions. Rectal temperature, respiration rate and coat surface temperatures in different body regions were measured every 7 d (0600, 1200, and 1800 h); also, testicular biometry was registered at 0600 h. Semen was collected via an artificial vagina 3 d after physiological variables were measured and seminal traits were evaluated. Rectal temperature, respiration rate and coat surface temperatures were higher (P < 0.01) at each hour of measurement in summer compared to spring. Overall, scrotal length and circumference, as well as testicular volume were higher (P < 0.01) in summer than in spring. Compared to spring conditions, summer HS caused lower (P ≤ 0.05) sperm concentration and viability combined with a higher percentage of sperm abnormalities without affecting ejaculate volume. Both mass and sperm motility were similar between seasons in the first two sampling weeks, and then decreased (P ≤ 0.03) due to summer HS. In conclusion, Dorper rams developed testicle hyperthermia and, consequently, showed poor semen quality due to the high environmental temperatures prevailing in desert regions.

Cryopreservation efficiency of red-rumped agouti (Dasyprocta leporina) sperm obtained from different origins through epididymal retrograde flushing or electroejaculation.

This study investigated whether the origin of sperm (epididymal vs. ejaculate) affects the cryopreservation efficiency in agouti (Dasyprocta leporina). Five sexually mature agoutis underwent electroejaculation, resulting in obtaining four semen samples. After 15 days, the same animals were euthanized, and through retrograde flushing, sperm samples were obtained from the epididymis tails. In both collection methods, samples were evaluated for sperm parameters (sperm concentration, motility, vigor, membrane integrity, osmotic response, and morphology). Then, samples were diluted in ACP 109c, added with 20% egg yolk, and a final concentration of 6% glycerol. Finally, the samples were packaged in 0.25 mL straws and frozen in liquid nitrogen. After one week, samples were thawed and evaluated in the same way as fresh samples, with the addition of membrane integrity analysis using fluorescent probes (C-FDA/PI) and computerized analysis (CASA). Immediately after obtaining the sperm, samples obtained directly from the epididymis presented higher values (P ≤ 0.05) than those obtained by electroejaculation concerning the parameters of volume, sperm concentration, and total number of sperm (1,398.25 ± 206.0 x106 and 184.5 ± 78.0 x106 sperm). On the other hand, in the classical evaluation of the other sperm parameters and the computerized analysis (CASA) after thawing, such as total motility, no statistical differences were observed between sperm from both origins (ejaculate: 16.7 ± 8.2% and epididymal: 24.8 ± 12.0%, P > 0.05). This demonstrates the possibility of direct application of the cryopreservation protocol for agouti (D. leporina) sperm obtained via the epididymis or ejaculate.

Comparison of two pharmacological semen collection times with α2-adrenergic agonist in domestic cats.

The use of α2-adrenergic agonists in association with urethral catheterization has been used as a technique for pharmacological semen collection in cats. The mechanism of action of this drug is the stimulation of adrenoreceptors in the vas deferens, which results in ejaculation. While medetomidine is the α2-agonist most commonly used in studies, ejaculation with the use of dexmedetomidine associated with ketamine has been effective, but with variable results. Therefore, further studies regarding the methodology of use are required to obtain better seminal quality. This study aimed to compare two pharmacological semen collection times after the association of dexmedetomidine (30 µg/kg, IM; Dormitor®, Zoetis), ketamine (5 mg/kg, IM; ketamine, Vetnil) and urethral catheterization using a tomcat probe (0.8 mm × 1.00 mm × 11 cm). The collections were divided into two experimental groups: G10 (N = 8; urethral catheterization after 10 min of anaesthesia) and G15 (N = 8; urethral catheterization after 15 min of anaesthesia). The ejaculates were evaluated for ejaculate volume, sperm concentration, morphology and kinetics using the CASA system. To compare the groups, the t-test and the Mann-Whitney U-test were used with a significance level of 5%. It was identified that ejaculate volume (G10: 22.62 ± 2.13 vs. G15: 26.81 ± 1.55; p < .001) and sperm concentration (G10: 48.10 × 106 ± 17.84 vs. G15: 90.18 × 106 ± 19.35; p < .001) was higher in G15 than in G10 and had a lower percentage of minor defects than G10 (G10: 3.12 ± 2.41 vs. G15: 1.00 ± 1.19; p = .043). Regarding the kinetic parameters, the results of G15 were better for total motility-TM (G10: 67.00 ± 10.33 vs. G15: 81.87 ± 7.99; p = .006) and faster cells-RAPID: (G10: 55.00 ± 16.63 vs. G15: 74.25 ± 11.94; p = .019); whereas a higher proportion of cells with slow speed-SLOW were seen in G10 (G10: 31.00 ± 12.07 vs. 17.12 ± 7.53; p = .015). Based on these findings, we suggest that collection via urethral catheterization should be performed 15 min after the application of ketamine-associated dexmedetomidine to obtain a better-quality ejaculate.

Activation of caspase-3/7, an apoptotic-related marker, during incubation and cryopreservation of alpaca (Vicugna pacos) spermatozoa.

Caspases are crucial mediators of programmed cell death (apoptosis). Apoptosis can occur in spermatozoa during spermatogenesis or epididymal transit, as well as in ejaculated spermatozoa. A high proportion of apoptotic sperm would be a poor indicator of the freezability of a raw seminal sample. Alpaca spermatozoa are notoriously difficult to freeze successfully. Therefore, the objectives of this study were to study caspase activation during incubation (37°C) of fresh alpaca spermatozoa, as well as before and after cryopreservation, to gain some insight into the mechanisms behind the vulnerability of alpaca spermatozoa. Eleven sperm samples were incubated for 4 h at 37°C (Study 1), and 23 samples were frozen using an automated system (Study 2). Caspase-3/7 activation was assessed at 0,1,2,3, and 4 h in samples incubated at 37°C (Study 1); and before/after cryopreservation (Study 2) using CellEvent™ Caspase 3/7 Green Detection Reagent and flow cytometry. The proportions of alpaca spermatozoa with caspase-3/7 activated increased (p < 0.05) after 3-4 h of incubation at 37°C; however, caspase activation was similar before and after cryopreservation (36.2 ± 11.2% vs. 36.6 ± 33.7%, p > 0.05). The high standard deviation found after freezing could be explained by the existence of two subpopulations: one subpopulation where caspase-3/7 activation decreased during cryopreservation (from 36.6 ± 9.1% to 1.5 ± 2.2%), and the other subpopulation where caspase-3/7 activation increased after cryopreservation (from 37.7 ± 13.0% to 64.3 ± 16.7%). In conclusion, after 3-4 h of incubation, caspase-3/7 activation increased in fresh alpaca sperm, whereas cryopreservation affects alpaca sperm samples in different ways.

Time of day modified the time required for semen collection with electroejaculation and slightly affected the quality of fresh semen in rams.

The aim was to compare some stress responses to electroejaculation (EE), and the quality of fresh semen, when ram semen is collected at dawn (06:00 h), noon (12:00 h), or evening (18:00 h). Twelve Corriedale rams were used, and semen was collected from four rams at each study time on three different days, with a Latin-square design. The time required for EE, the number of vocalizations emitted, heart rate, and rectal temperature were recorded, and fresh semen was evaluated. The time required for EE was shorter at evening than at dawn and noon (399.3 s, 480.6 s, and 460.2 s respectively; pooled SEM = 72.1; P = 0.03). The percentage of sperm with progressive motility was greater at noon than dawn (59.7% and 50.3%; pooled SEM = 5.8; P = 0.05). Curvilinear velocity was greater at dawn than evening (117.0 µm/s and 95.5 µm/s; pooled SEM = 7.1; P = 0.04), slow linear velocity was greater at evening than at dawn and noon (13.1 µm/s, 9.3 µm/s, and 8.5 µm/s respectively; pooled SEM = 1.7, P = 0.05), and the slow average path velocity was greater at evening than dawn and noon (16.2 µm/s, 11.7 µm/s, and 10.8 µm/s respectively; pooled SEM = 1.9, P = 0.05). In conclusion, the collection time modified the time required for electroejaculation and had only slight effects on the quality of fresh semen. Overall, the time of the day appears to have only slight effects on semen collection and quality.

Seasonality does not influence cortisol or testosterone production, or seminal quality of stallions located at low latitudes.

The effects of seasonality on the reproduction of stallions vary based on the latitude. Although previous studies have shown the influence of seasonality in raw semen quality in south-eastern Brazil, data regarding the influence of seasonality in cooled and frozen stored semen in Brazil is limited. Therefore, in this study, we have analysed if seasonality influences the hormone production (i.e., cortisol and testosterone), spermatogenesis, and quality of fresh, cooled, and frozen semen of stallions in central Brazil, and established the season most suitable for semen cryopreservation in a latitude of 15°S. Ten stallions were followed-up for one year, which was divided into two seasons, namely, drought, and rainy. Fresh, cooled, and frozen-thawed semen samples were assessed using CASA and flow cytometry. Additionally, the temperature and humidity index (THI) was calculated to determine the thermal stress. Although the THI varied between the two seasons, no thermal stress was observed throughout the year, nor were there differences in the physiological parameters of the stallions or plasma cortisol or testosterone levels. Furthermore, differences were not detected in total and progressive motility, sperm capacitation, and sperm membrane integrity, as well as in the number of live sperm with intact acrosomes and high mitochondrial membrane potential, between the two seasons in the fresh and frozen-thawed semen. Our data suggest that semen can be effectively collected and cryopreserved throughout the year within central regions of Brazil.

Effects of heat stress on sperm quality of French Bulldogs.

This study aimed to evaluate the effects of heat stress (HS) and its duration on semen quality, serum testosterone, pulsatility and resistibility index of the testicular artery of French Bulldogs. Eight male French Bulldogs, 3-7 years old, 12.63 ± 1.8 Kg were adapted and trained for two months. Room temperature was 21 °C. Semen was collected by digital stimulation. The median of four andrological evaluations was T0. Heat was applied to the scrotum using an electrical heat pad at 40 °C for 11 min. Rectal temperature (RT) and scrotum temperature were evaluated using a mercury thermometer and an infrared thermography camera before and after HS. Semen was evaluated immediately (T1) and after seven (T7), 14 (T14), 21 (T21), 28 (T28) and 60 (T60) days after HS. Semen parameters included macroscopic (volume, color and viscosity) and microscopic (sperm motility and vigor, percentage of morphologically normal or defected spermatozoa, sperm concentration and total number of sperm cells) aspects. A pulsed colored doppler ultrasound was performed on the testicular artery at the spermatic cord and epididymis region before and immediately after HS. Serum testosterone was analyzed before, 48 and 96 h after HS. Data was analyzed by ANOVA using SAS. There was a 1.23 °C increase on RT and a 4.98 °C increase on thermograph after HS. Sperm motility decreased at T1 (P < 0.05) and tended to stay lower at T7 (P = 0.056). It improved at T14, but reduced again at T21 (P < 0.05). At T28 and T60 motility was normal. Vigor was lower at T1 (P < 0.05), normal at T7 and T14, but decreased at T21 (P = 0.054), at T28 and T60 it was not different than T0. Sperm concentration was lower at T1 (P < 0.05) and not different from T0 at other timepoints. Volume color and viscosity were not different. Total sperm per ejaculate was reduced at T1 and T7 (P < 0.05) and tended to be lower at T14 (P = 0.057). T21, T28 and T60 were not different than T0. There was a decrease in normal sperm cells and an increase in defected sperm at T7. There was no difference within T14, T21, T28 and T60. The raise in pathologies at T7 was from an increase in minor defects (P < 0.05). There was no difference in serum concentration of testosterone nor pulsatility and resistivity index before and after HS. In conclusion, induction of HS directly to the testis reduces sperm quality in French Bulldog. This impairment is immediately and transitory.

Donkey semen cryopreservation: Alternatives with permeable, non-permeable cryoprotectants and seminal plasma.

Cryopreservation of semen is an important technique to preserve genetic material. Yet, pregnancy rates in jennies after artificial insemination with frozen-thawed donkey semen are poor. This condition has been attributed to the impact of permeable cryoprotectants, that could cause high post-breeding endometritis. Removal of seminal plasma (SP) prior to semen freezing process is another contributing factor. SP is involved in a multitude of sperm functions and events preceding fertilization and has a mediating effect of sperm capacitation and postcoital uterine inflammatory response. The aim of this study was to evaluate different alternatives in donkey semen cryopreservation with permeable, non-permeable cryoprotectants, BSA and SP. Thirty ejaculates from 10 donkeys were cryopreserved with different combinations of dimethylformamide (DMF, 5%), sucrose (SUC, 200 mM) and homologous SP (10%): DMF (T1), DMF/SP (T2), SUC/BSA (T3), SUC/BSA/SP (T4), DMF/SUC/BSA (T5), DMF/SUC/BSA/SP (T6), DMF/BSA (T7) and DMF/BSA/SP (T8). After thawing, sperm motility and kinetics were assessed by computerized semen analysis. Sperm vitality (SV) was evaluated by fluorescence microscopy, functional membrane integrity (FMI) by the HOST test, abnormal morphology by eosin-nigrosin staining and sperm membrane stability by flow cytometry. For statistical analysis, sperm quality indexes (SQi) were obtained, general linear models were carried out and mean comparisons were made by the Tukey test. T1, T2, T5, T6, and T7 had higher and equivalent results for motility, most kinetic parameters and function membrane integrity. Cryopreservation of donkey semen without permeable cryoprotectant (T3 and T4) showed a reduction in motility, kinetics, SV, FMI and SQi. T5 showed a reduction in progressive motility, sperm velocities, IMF and SQi compared to other DMF treatments. T6 and T8 achieved higher SQi values compared to T1, but they were not different compared to T2 and T7. T1 had a smaller sperm population with low-M540 compared to T3. It is concluded that the use of permeable cryoprotectant is essential to achieve higher post-thaw quality of donkey semen. In addition, the combined use of BSA, SUC and/or PS may provide additional sperm protection compared to the individual use of DMF.

Administration of carbetocin-a long-acting oxytocin analogue-before sperm collection by transrectal ultrasound-guided massage of the accessory sex glands in bucks (Capra hircus) and ibexes (Capra pyrenaica).

Transrectal ultrasonic-guided massage of the accessory sex glands (TUMASG) is a technique that allows collecting semen requiring few electrical stimuli or even no pulse. A long-acting analogue of oxytocin (carbetocin, 0.1 mg) was i.v. administered before TUMASG in 10 conscious bucks (Experiment 1) and 10 anaesthetized Iberian ibexes (Experiment 2) to shorten the time of semen collection, decrease the number of electrical stimuli and/or improve the semen quality. The ejaculated volume, concentration, quality parameters and kinetics variables of the sperm were determined in fresh semen. The time length of the procedures and the number of electric pulses applied were recorded. Furthermore, stress response indicators (number of vocalizations in Experiment 1; heart and respiratory rates, rectal temperature, cortisol levels, totals proteins and neutrophil-to-lymphocyte ratio in Experiment 2) were documented. In bucks, the administration of carbetocin tended to shorten the time needed for semen collection but no-showed differences in the fresh seminal quality. In the Iberian ibexes, there were no significant differences between groups in the time length of procedures or in the number of animals that ejaculated. Carbetocin administration only reduced the respiratory rate, did it modify fresh semen characteristics in ibexes. In conclusion, the administration of carbetocin did not appear as a useful tool to improve welfare during semen collection with TUMASG or semen quality in conscious bucks and anaesthetized ibexes, having only slight advantages related to the procedure.

Testicular hypoplasia in Nellore Cattle: Genetic analysis and functional analysis of genome-wide association study results.

Characterized by the incomplete development of the germinal epithelium of the seminiferous tubules, Testicular hypoplasia (TH) leads to decreased sperm concentration, increased morphological changes in sperm and azoospermia. Economic losses resulting from the disposal of affected bulls reduce the efficiency of meat production systems. A genome-wide association study and functional analysis were performed to identify genomic windows and the underlying positional candidate genes associated with TH in Nellore cattle. Phenotypic and pedigree data from 207,195 animals and genotypes (461,057 single nucleotide polymorphism, SNP) from 17,326 sires were used in this study. TH was evaluated as a binary trait measured at 18 months of age. A possible correlated response on TH resulting from the selection for scrotal circumference was evaluated by using a two-trait analysis. Thus, estimated breeding values were calculated by fitting a linear-threshold animal model in a Bayesian approach. The SNP effects were estimated using the weighted single-step genomic BLUP method. Twelve non-overlapping windows of 20 adjacent SNP that explained more than 1% of the additive genetic variance were selected for candidate gene annotation. Functional and gene prioritization analysis of the candidate genes identified genes (KHDRBS3, GPX5, STAR, ERLIN2), which might play an important role in the expression of TH due to their known roles in the spermatogenesis process, synthesis of steroids and lipid metabolism.

Importância do plasma seminal na qualidade e preservação do espermatozoide suíno / Importance of seminal plasma in the quality and preservation of boar sperm

Ao preservar o espermatozoide suíno no estado líquido ou criopreservado, os componentes do plasma seminal (PS) contidos nos ejaculados podem alterar a capacidade de fertilização desses gametas. O PS contém substâncias essenciais para a manutenção da viabilidade e fertilidade dos espermatozoides. No entanto, esses componentes podem ser deletérios dependendo da quantidade ou duração do tempo de contato entre a ejaculação e a remoção do PS durante o processamento do sêmen para a conservação na forma refrigerada ou congelada. Foram identificadas substâncias que prejudicam (principal proteína plasmática seminal PSPI) ou melhoram (espermadesina PSP-I) a capacidade de fertilização dos espermatozoides. Dependendo dos cachaços e dos procedimentos de colheita de sêmen, a remoção do PS pode ser benéfica antes da preservação no estado líquido ou criopreservado. Em alguns casos, o PS removido antes da congelação pode ser adicionado de volta ao diluente de descongelamento, com efeitos positivos no sêmen descongelado e na viabilidade do espermatozoide no trato reprodutivo da porca. Neste texto, há um foco nos diferentes efeitos de PS em amostras de sêmen refrigerado e criopreservado de suínos com ênfase em como PS modula a função e morfologia das células espermáticas antes, durante e após a preservação de forma refrigerada ou criopreservada.(AU)

When preserving sperm in the liquid or cryopreserved state, seminal plasma (SP) components within ejaculates can alter fertilizing capacity of these gametes. The SP contains substances essential for maintenance of sperm viability and fertility; however, these components can be deleterious depending on quantity, or duration of time before there is removal of SP from sperm in semen processing. Substances that impair (Major seminal plasma protein PSPI - boar) or improve (e.g., spermadhesin PSP-I - boar) sper- matozoa fertilizing capacity have been identified. Depending on individual males and semen collection procedures, SP removal may be beneficial before preservation in the liquid or cryopreserved state. In some cases, SP that is removed can be added back to thawing extender with there being positive effects in thawed sperm and for sperm viability in the female reproductive tract. In this review article, there is a focus on different effects of SP in samples of cooled and cryopreserved semen from boar with there being emphasis on how SP modulates the function and morphology of sperm cells before, during, and after preservation in the refrigerated or cryopreserved state.(AU)

Canine sperm vitrification with nonpermeable cryoprotectants and coconut water extender

This study was aimed to assess the efficiency of coconut water extender with addition of soy lecithin and sucrose as nonpermeable cryoprotectants for canine semen vitrification, using a simple method that yields a high survival rate of spermatozoa for clinical use. Twelve ejaculates from 12 adult normozoospermic dogs were collected separately by digital manipulation and only the second semen fraction was used in this study. After evaluation of volume, concentration, viability, total and progressive motility, velocity parameters and morphology, semen was diluted with a coconut water extender (50% (v/v(volume per volume)) coconut water, 25% (v/v) distilled water and 25% (v/v) 5% anhydrous monosodium citrate solution) with addition of soy lecithin and fructose at 1% and 0.25M sucrose until final concentration of 100x106 spermatozoa/ml. After equilibration at 5ºC for 60 minutes, semen was vitrified by "direct dropping method" into liquid nitrogen in spheres with a volume of 30 µl. After a week of storage the spheres were devitrified as three of them were dropped into 0.5 mL of CaniPlus AI medium (Minitüb, Germany), which was previously warmed in a water bath at 42ºC for 2 minutes and evaluated about the above mentioned parameters. It was found that vitrification resulted in a lower percentage of viable sperms, normal morphology, total and progressive motilities (p0.05) compared to fresh semen samples. In conclusion, our results demonstrate that vitrification with coconut water extender with addition of 1% soy lecithin and 0.25M sucrose as cryoprotectants, has an excellent potential for routine canine sperm cryopreservation.(AU)

Kallikrein proteoforms and reproductive parameters in stallion are conditioned by climate.

Horses are seasonal polyoestrous animals, and the photoperiod is the main factor modulating their reproductive activity. There is no consensus on the andrological and biochemical factors that influence breeding seasonality. To assess the involvement of climate in reproduction, Mangalarga Marchador stallions were monitored over 1 year regarding semen quality and seminal plasma proteome. Here, we show that kallikrein (KLKs) proteoforms in seminal plasma are involved in climate conditioning of reproduction. During the breeding season, greater abundance and different types of KLKs occurred simultaneously to lower sperm motility, greater semen volumes and higher concentrations of glucose and cholesterol. Considering that vasodilation due to activation of the kallikrein-kinin system and the consequent inhibition of the renin-angiotensin system may be associated with lower sperm motility, unravelling the involvement of KLK proteoforms in reproductive seasonality is a priority in horse breeding.