The effects of supplementation of vitamin D to the egg-yolk extender on cryopreservation of ram semen.

OBJECTIVES: This study aimed to examine the effects of supplementation of vitamin D to the egg-yolk extender on characteristics of frozen-thawed ram semen. METHODS: Semen samples obtained from adult rams were pooled and divided into five equal volumes. It was reconstituted with extenders containing different concentrations of vitamin D: 0 (control), 12.5 (VITD 12.5), 25 (VITD 25), 50 (VITD 50), and 100 ng/mL (VITD 100), and then they were frozen. Sperm motility parameters, plasma membrane functional integrity, acrosomal integrity, DNA fragmentation, and mitochondrial membrane potential of the groups were evaluated after sperm thawing. RESULTS: Total motility and progressive motility were higher in VITD 50 than in all other groups (p < 0.05). Higher sperm straightness, linearity, and wooble were higher in VITD 50 than in the control group (p < 0.05). A similar pattern of VITD 50 was observed for plasma membrane integrity and mitochondrial membrane potential (p > 0.05). CONCLUSIONS: In the study, it was observed that adding vitamin D to the extender had a beneficial effect on ram spermatological parameters. In addition, it was concluded that the use of the 50 ng/mL vitamin D in the extender provided more effective protection than the other doses.

Improving semen quality of rams fed with ration containing protected maggot oil.

The study aimed to to evaluate the effect of feeding protected maggot oil at different levels on the ram sperm quality. The study used 15 local rams with an age of approximately 10-12 months and an initial weight of 19.99 ± 3.97 kg. The feeding rate was 4% of body weight per day. Feed was given 3 times a day, specifically in the morning (08.00 WIB), afternoon (12.00 WIB) and evening (16.00 WIB). Water was provided ad libitum. This study used 3 treatments and 5 groups as replicates. The treatments used concentrates with different levels of protected maggot oil: P0(0% protected maggot oil (control)), P1(4% protected maggot oil), and P2(8% protected maggot oil). The variables measured were nutrient consumption, blood cholesterol levels, scrotal circumference, and sperm quality. Blood cholesterol and scrotal circumference measured at the end of the experimental diet. Semen samples were collected and analysed before and at the end of the experimental diet. The data obtained were analysed using ANOVA, with further testing using Duncan's test for significant differences. The results showed that there were no significant differences in the consumption of dry matter, crude protein, crude fiber, scrotal circumference, volume, colour, pH of semen, sperm concentration, live percentage, abnormal percentage, plasma membrane, and acrosome integrity of spermatozoa. There were significantly (p < 0.05) produced higher consumption of oleic and palmitic acids in 8% protected maggot oil compared to 4% treatments, the treatments containing 4% and 8% protected maggot oil produced significantly (p < 0.05) higher consumption of lauric and myristic acids, blood cholesterol levels, and sperm motility than the control. The result indicates that protected maggot oil up to 8% in the ram diet have positive effect on improving the microscopic quality of ram sperm, i.e. increased sperm motility.

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.

Characteristics of Bachaur bull semen.

The Bachaur is a mediumized draft purpose breed which has been recognized by ICAR-National Bureau of Animal Genetic Resources (NBAGR) Karnal, India, and presently is on the verge of extinction. Since there are no data regarding the seminal parameters of this breed, this work was performed to evaluate seminal parameters of freshly ejaculated semen. A total of three healthy breeding Bachaur bulls aged 2.5-5 years were selected for the study which were maintained under identical managemental conditions. Semen parameters of these bulls were studied across 10 ejaculates. The average scrotal circumference and testicular weight of the three bulls were 27.78 ± 1.2 cm and 400.67 ± 26.6 g, respectively. The average overall volume (mL), pH, concentration (million/mL), liveability (%), abnormality (%), HOST (%) and acrosome integrity (%) were 2.20 ± 0.19, 6.86 ± 0.06, 1245.60 ± 23.49, 85.09 ± 0.91, 4.13 ± 0.06, 81.16 ± 1.18 and 83.54 ± 1.32, respectively. The average overall mass motility of three Bachaur bulls was 3.57 ± 0.06 in 0-5 scale and individual motility averaged 84.78 ± 1.70 per cent. The volume of ejaculates in Bachaur bull seemed to be lower as compared to other exotic and Indian breeds. However, the semen parameters with regard to mass motility, liveability, abnormalities, hypo-osmotic swelling test (HOST) and acrosomal integrity seemed similar to other exotic and Indian breeds.

Plasticity in moth mating behavior and ejaculate proteomic diversity induced by male competition.

In male competition, large and costly ejaculates are advantageous. Prior research on male accessory gland secretions in Plutella xylostella left open questions about how males modulate their mating behaviors and ejaculate composition allocation in response to varying levels of competition. The current study aimed to delve deeper into these unexplored facets. A totally of 928 ejaculate proteins were identified across males exposed to different competition conditions. Notably, males courting under non-, low-, and high-competition scenarios exhibited 867, 635, and 858 ejaculate proteins, respectively. Approximately 10% of these ejaculate proteins displayed variations that aligned with changes in competition intensity. Subsequent analyses focused on the proteins transferred to females, revealing that 44% of ejaculate proteins were transferred, with 37 proteins exhibiting differential expression. Functional analyses uncovered their crucial roles in sperm maturation, motility, and capacitation. Our findings reveal adaptive adjustments in ejaculate protein abundance and transmission in P. xylostella as a response to varying competition levels. Moreover, fluorescent sperm labeling indicated higher sperm transfer during low competition correlated with shorter sperm length. Furthermore, evidence suggests that males shorten their courtship duration and extend their mating duration when faced with competition. These results illustrate how competition drives ejaculate investment and behavioral plasticity, offering valuable insights for advancements in assisted reproductive technologies and pest management strategies.

Effects of natural mating, artificial insemination and intravaginal deposition of raw semen or seminal plasma on vaginal and uterine blood flow in German Holstein cows.

AIM: The present study was performed to characterize and compare the perfusion of vaginal and uterine arteries after challenging the reproductive tract of dairy cows via natural mating, artificial insemination (AI), or intravaginal deposition (vaginal fundus) of different biological fluids or a placebo. MATERIALS AND METHODS: In a double-blind study, six German Holstein cows were administered PGF2α during dioestrus and 48 h later treated with GnRH. Intravaginal or intrauterine treatments were carried out 12 h after GnRH was administered. Animals served as their controls, using a cross-over design with an interval of 14 days between experiments. The experimental animals were allocated to receive the following treatments: natural mating (N), intrauterine artificial insemination (A), intravaginal deposition (vaginal fundus) of 6 mL raw semen (R) or 6 mL seminal plasma (S), and compared to their controls [control 1: 6 mL placebo (P: physiological saline); control 2: no treatment (C)). Corresponding time intervals were chosen for the untreated control oestrus. Blood flow volume (BFV) in the uterine (u) and vaginal (v) arteries ipsilateral to the ovary bearing the preovulatory follicle was determined using transrectal Doppler sonography. RESULTS: All animals exhibited oestrus and ovulated between 30 and 36 h after GnRH. Transient increases (P < 0.05) in vaginal blood flow occurred between 3 and 12 h following mating as well as 3 to 9 h after deposition of raw semen and seminal plasma, respectively. The most distinct increases (199%) in vBFV occurred 6 h after mating compared to values immediately before mating (= time 0 h). Neither AI nor deposition of a placebo into the vagina affected vBFV (P > 0.05). Only mating and deposition of either raw semen, seminal plasma or AI increased uBFV (P < 0.003). The greatest rise in uBFV occurred after natural mating. Maximum uBFV values were detected 9 h after mating when values were 79% greater (P < 0.05) than at 0 h. CONCLUSIONS: The natural mating, deposition of raw semen or seminal plasma and conventional AI affect vaginal and/or uterine blood flow to different degrees. The factors responsible for these alterations in blood flow and their effects on fertility remain to be clarified in future studies.

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.

Gallic acid supplementation partially ameliorates reproductive aging in rooster breeders by improving semen quality, sperm kinetics, hormones, and antioxidant status.

Aging leads to decreased fertility in roosters, which is likely due to increased oxidative stress. This study evaluated the antioxidant effects of gallic acid (GA) supplementation on sperm quality and fertility of aged roosters. This study evaluated whether GA supplementation can mitigate age-related fertility decline. Roosters were randomly assigned to: control, 100 mg/kg GA, or 200 mg/kg GA. Semen parameters, sperm kinetics, hormone levels, fertility rate, and hatchability were assessed. GA increased semen concentration, membrane integrity and viability while decreasing defects versus control (P < 0.01). Testosterone was higher in GA groups (P<0.01) without affecting gonadotropins. Furthermore, 200 mg/kg GA optimized motility, velocity, linearity, and beat cross frequency versus control and 100 mg/kg GA (P < 0.01). Fertility and hatchability were higher in both GA groups. In conclusion, GA supplementation in aged roosters improves sperm quality, antioxidant status, testosterone, and fertility outcomes, likely by mitigating oxidative stress. The 200 mg/kg dose elicited optimal effects on motion parameters.

Adjusting ram semen preservation: Exploring the impact of oxygen exposure during liquid storage.

This study investigated the effects of storage conditions on the quality of chilled ram semen stored at 4°C for 48 h, comparing aerobic and anaerobic conditions. Ejaculates from INRA180 rams were collected and stored under both conditions, with assessments at 0-, 24-, and 48-h intervals. Various sperm parameters were examined, including motility, velocity, viability, morphology, membrane integrity, and lipid peroxidation. Results showed that storage duration significantly impacted sperm quality, leading to a gradual decline from 0 to 24 h and 24 to 48 h. Notably, after the initial 24 h, progressive motility (PM) and membrane integrity (MI) demonstrated distinct responses to storage conditions. Anaerobic storage consistently improved PM and MI values compared to aerobic storage between 24 and 48 h. Anaerobic conditions also enhanced viability and reduced abnormality at the 48-h mark. Total motility remained stable throughout storage. Velocity parameters (VCL: curvilinear velocity; VSL: straight velocity and VAP: velocity average path) exhibited differences between the 24- and 48-h intervals, with anaerobic storage resulting in higher VAP and VSL values. Moreover, lipid peroxidation exhibited a progressive increase from 0 to 24 h and 24 to 48 h, independent of storage conditions. Remarkably, anaerobic storage consistently yielded lower lipid peroxidation levels compared to aerobic storage, regardless of storage duration. In conclusion, this study highlights that the anaerobic storage proved advantageous for chilled ram semen quality, particularly after the initial 24 h.

Birth weight, growth indices, and seminal parameters in male offspring are resilient features to maternal pre-conceptional dietary manipulation in sheep.

Gestational diet manipulation can lead to inadequate fetal nutrient supply resulting in low birth weight, limited postnatal growth, and consequently, reduced reproductive performance in the progeny. However, effects of short-term maternal pre-conceptional dietary manipulation on postnatal growth and reproductive parameters of male offspring in large animals remains unexplored. To determine these consequences, female crossbred (Polypay x Dorset) sheep were allocated to three groups (n = 33/group) of dietary manipulation for 21 days prior to mating under the following conditions: (1) control at 100 % of maintenance energy requirements (40 Kcal of metabolizable energy/kg body weight [BW]), (2) undernutrition (UN) at 50 % of Control intake, and (3) overnutrition (ON) at 200 % of maintenance energy. Singleton ram lambs (UN:9; C:12; ON:6) were monitored from birth until 8 months of age, including birth weight, weekly weights, weight gain, body mass index (BMI), and circulating testosterone. After weaning, monthly scrotal circumference and subcutaneous fat depth were measured. Semen morphology and motility were evaluated at 7 and 8 months of age. Birth weight, weight gain, and BMI at birth and weaning were not significantly different among nutritional treatments. None of the pre-conceptional diets affected body weight change from weaning until 36 weeks of age, BMI, fat depth, or scrotal circumference across the experiment. A sustained rise in plasma testosterone concentrations was detected when ram lambs were, on average, 82 days old and 37 kg. Both testosterone concentrations and scrotal circumference were positively correlated to body weight regardless of treatment group. In addition, seminal parameters did not differ among treatments, but a transient increase in plasma testosterone at 18 weeks of age was observed in ON ram lambs compared to control rams. In conclusion, birth weight, growth indices, and seminal parameters in singleton rams are resilient features in the progeny upon maternal pre-conceptional dietary manipulation in sheep.

Principal component analysis of phenotypic and breeding value data for semen traits in Egyptian buffalo bulls.

Buffalo bull semen traits are economically important traits that influence farm fertility and profitability. Genetic improvement of semen characteristics is an important detail of the genetic improvement. This study was conducted to assess the relationship between the breeding values as well as the phenotypic values for semen traits (VOL, MM, LS, AS and CONC) of the Egyptian buffalo bulls. A total of 7761 normal semen ejaculates were collected and characterized at ILMTC laboratory from 26 bulls from 2009 to 2019. For VOL, MM, LS, AS, and CONC, the actual means were 3.89 mL, 62.37%, 60.64%, 3.94%, and 0.67 × 109 sperm/mL, respectively. The prediction of breeding values for semen traits was estimated using a Bayesian procedure. The estimated standardized EBVs and phenotypic values were used in the principal component analysis (PCA). Of five PCs, one PC (PC1) had > 1 eigenvalues that was responsible for 87.19% of the total variation of SEBV, and two PCs had > 1 eigenvalues that were responsible for 59.61% and 21.35% of the total variation of the phenotypic values. Together, PC1 and PC2 accounted for 97.97% of the total variance of SEBV and 80.96% of the total variance of phenotypic values. A graphs of the first two components showed the traits separated into two different directions by group. This indicates each group was under similar genetic influence. Therefore, selection can be done separately for each group without influencing the other. Principal component analysis reduced variables to describe the key information in buffalo semen data.

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.

Intra-horn insemination in the alpaca Vicugna pacos: Copulatory wounding and deep sperm deposition.

Alpacas (Vicugna pacos) are reported to be the rare mammal in which the penis enters the uterus in mating. To date, however, only circumstantial evidence supports this assertion. Using female alpacas culled for meat, we determined that the alpaca penis penetrates to the very tips of the uterine horns, abrading the tract and breaking fine blood vessels. All female alpacas sacrificed one hour or 24 hours after mating showed conspicuous bleeding in the epithelium of some region of their reproductive tract, including the hymen, cervix and the tips of each uterine horn, but typically not in the vagina. Unmated females showed no evidence of conspicuous bleeding. Histological examination of mated females revealed widespread abrasion of the cervical and endometrial epithelium, injuries absent in unmated females. Within one hour of mating, sperm were already present in the oviduct. The male alpaca's cartilaginous penis tip with a hardened urethral process is likely responsible for the copulatory abrasion. The entire female reproductive tract interacts with the penis, functioning like a vagina. Alpacas are induced ovulators, and wounding may hasten delivery of the seminal ovulation-inducing factor beta-NGF into the female's blood stream. There is no evidence of sexual conflict in copulation in alpaca, and thus wounding may also be one of a variety of mechanisms devised by mammals to induce a beneficial, short-term inflammatory response that stimulates blastocyst implantation, the uterine remodeling associated with placental development, and thus the success of early pregnancy.

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.

Developing Sex: From Recremental Semen to Developmental Endocrinology.

During the 1890s, animal development became associated with glandular activity, with profound implications for pediatric nosology and treatment. The significance of this endocrinological turn of developmental physiology and pathophysiology in part hinges on an often-overlooked continuity with ubiquitous early modern medical thought concerning semen as a recrementitious (reabsorbed) nutrient or stimulant. Mid-19th-century interests in adult sexual physiology were increasingly nerve-centered and antihumoral. Scattered empirical, particularly veterinarian, interests in gonadal developmental functions failed to moderate these explanatory trends. While Brown-Séquard's rejuvenation experiments still offered no clear starting point for a developmental endocrinology, in 1892 Gaston Variot and Paul Bezançon more explicitly deduced a testicular developmental endocrinological function from various observations on testicular ectopy and a local form of animal "demi-castration." Ensuing interest in the thyroid, the thymus and in the testicles led to various working conceptions of their respective and putatively reciprocal developmental properties, including the idea of a thyroid-testis axis. From 1896, the pubertal affliction of chlorosis became the subject of multiple opotherapeutic approaches, providing an experimental basis for theories of ovarian internal secretion. Polyglandular therapy, piloted for divergent developmental conditions, remained routine until the 1930s despite the biological inefficacy of many endocrine products.

Estimation of genetic parameters for bull conception rate and its genetic correlations with semen production traits in Japanese Black bulls.

The P of achieving pregnancy is an important trait of bull fertility in beef cattle and is defined as the bull conception rate (BCR). This study aimed to clarify and better understand the genetic architecture of the BCR calculated using artificial insemination and pregnancy diagnosis records from a progeny testing program in Japanese Black bulls. In this study, we estimated the genetic parameters of the BCR and their correlation with semen production traits. In addition, we assessed the correlated responses in BCR by considering the selection of semen production traits. Nine hundred and sixteen Japanese Black bulls were selected based on fertility, with 28 869 pregnancy diagnostic records from the progeny testing program. Our results showed that the heritability estimate was 0.04 in the BCR at the first service and 0.14 in BCR for the three services, and an increase in the inbreeding coefficient led to a significant decrease in BCR. The phenotypic trend of BCR remained almost constant over the years, whereas the genetic trend increased. In addition, the changes in the progeny testing year effect showed a similar tendency to the phenotypic trends, suggesting that the phenotypic trends could be mainly due to non-genetic effects, including progeny testing year effects. The estimated genetic correlation of BCR with sperm motility traits was favorably moderate to high (ranging from 0.49 to 0.97), and those with sperm quantity traits such as semen volume were favorably low to moderate (ranging from 0.23 to 0.51). In addition, the correlated responses in BCR at the first service by selection for sperm motility traits resulted in a higher genetic gain than direct selection. This study provides new insights into the genetic factors affecting BCR and the possibility of implementing genetic selection to improve BCR by selecting sperm motility traits in Japanese Black bulls.

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.

Alpha-lipoic acid improves cryopreservation of rooster semen by reducing oxidative stress.

Inhibiting oxidative stress is key for ensuring sperm motility during semen cryopreservation. The aim of this study was to investigate the effect of adding alpha-lipoic acid (ALA) as an extender in rooster semen cryopreservation. Different concentrations of ALA were added to the frozen diluent of rooster semen; subsequently, computer-aided semen analysis was used to determine membrane functional integrity, acrosome integrity, antioxidant capacity (based on T-AOC, GSH-Px, SOD, CAT, and MDA contents), and mitochondrial integrity. The frozen sperm ultrastructure was observed using transmission electron microscopy. The results showed that the addition of different concentrations of ALA partially to greatly improved the quality of frozen sperm; in particular, 8 µg/mL ALA significantly improved multiple parameters of sperm quality, including sperm motility and antioxidant enzyme activity, after freeze-thaw. The results of this study provide empirical and theoretical support for effective rooster semen cryopreservation and can inform the development of new protective agents in the field of livestock reproduction.

A single administration of carbetocin before electroejaculation increases the insemination doses produced from each ejaculate in rams.

The aim of the study was to determine the effect of carbetocin administration (a long-acting analog of oxytocin) 20 or 10 min before electroejaculation (EE) on the duration of semen collection procedure, quantitative and qualitative characteristics of the ejaculate, and stress biomarkers in rams. Semen was collected from 12 Corriedale rams (age, 2.5-5.5 years old) with EE, in a Latin-square design, administrating carbetocin (0.2 mg/100 kg of body weight i.v.) 20 or 10 min before EE, or without carbetocin administration (CB-20, CB-10, and CON treatments, respectively). Each treatment was applied to different rams every 3-4 days, allowing all the rams to receive all three treatments. Carbetocin administered 20 or 10 min before EE increased the number of sperm ejaculated (P = 0.01), the semen concentration (P = 0.02), the number of insemination doses collected in a single collection (P = 0.01), and the number of insemination doses collected/electrical pulses administered (P = 0.05) compared to control rams. Carbetocin administered 20 or 10 min before semen collection prolonged the time required for EE and the number of pulses administered during EE compared to CON rams (P < 0.03 for both). The CB-10 rams required the administration of more electrical pulses during ejaculation than CON rams (P = 0.001), and CB-20 treatment tended to require more electrical pulses than CON rams (P = 0.06). The volume of the ejaculate was greater in CB-10 than in CON rams (P = 0.01), and that of CB-20 treatment tended to be greater than CON rams (P = 0.08). The percentage of sperm with intact membrane was greater in CB-20 than in CON rams (P = 0.01). Total protein, albumin, and globulin concentrations were lower immediately after carbetocin administration 20 or 10 min before EE. The treatments did not affect cortisol concentration, glycemia, rectal and surface temperatures, heart rate, and facial expressions. Carbetocin administration before EE of rams improved the quantitative and qualitative characteristics of the ejaculate, duplicating the number of insemination doses collected. It can be a promising treatment to obtain a greater quantity of doses to inseminate with a lower frequency of semen collections, reducing the negative impacts of EE on animal welfare.