Search Results (27)

This study optimized the cryopreservation protocol for cashmere goat semen by testing centrifugation speeds (750, 1000, 1250, 1500 rpm) for seminal plasma removal and L-proline concentrations (10, 30, 50 mmol/L) in a freezing extender. Semen from six 3-year-old breeding bucks of Inner Mongolia cashmere goats was evaluated post-thaw in terms of motility, membrane integrity, antioxidant capacity, and artificial insemination (AI) outcomes (n = 130 does). The results demonstrated that the group that underwent centrifugation at 1250 rpm saw significantly improved sperm motility (p < 0.05), curvilinear velocity (VCL, p < 0.05), and straight-line velocity (VSL, p < 0.05) compared to the other groups. The addition of 30 mmol/L L-proline further enhanced post-thaw sperm motility (p < 0.05), plasma membrane integrity (p < 0.05), and acrosome integrity (p < 0.05), while significantly reducing reactive oxygen species (ROS, p < 0.05) and malondialdehyde (MDA, p < 0.05) levels. This group also exhibited the highest antioxidant capacity, as indicated by elevated levels of total antioxidant capacity (T-AOC), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) (p < 0.05). AI trials revealed that semen treated with 1250 rpm centrifugation and 30 mmol/L L-proline achieved the highest kidding rate (56.82%), significantly outperforming the control group (37.21%, p < 0.05). Meanwhile, no significant differences were observed in prolificacy or offspring sex ratio (p > 0.05). In conclusion, this study demonstrates that combining 1250 rpm centrifugation for seminal plasma removal with the addition of 30 mmol/L L-proline to the freezing extender significantly improves the quality of cryopreserved cashmere goat semen and enhances AI outcomes. Full article

Artificial insemination in goats commonly relies on refrigerated semen doses, yet the optimal energetic substrate to support sperm metabolism remains unclear. This study aimed to evaluate the effects of different energetic substrates on goat buck sperm metabolism and motility when refrigerated at 17 °C. Semen from six Murciano-Granadina male goats were collected and diluted in PBS supplemented with 35 mM of either glucose, fructose, pyruvate, or lactate in the first experiment. In the second experiment, the effects of varying concentrations of pyruvate and/or glucose, NaCl supplementation, and the osmolarity on sperm quality parameters were assessed. Semen was stored at 17 °C for 48 h and evaluated for motility using the CASA system, as well as for viability, mitochondrial membrane potential, and mitochondrial ROS by flow cytometry. The results show that pyruvate and lactate extenders outperformed the others, preserving higher total motility, progressivity, and viability of spermatozoa over 48 h, even at a concentration lower than 35 mM, as in the case of pyruvate. In contrast, glucose had a detrimental effect on sperm quality, reducing viability and healthy population rates while increasing motility, especially at higher concentrations. NaCl supplementation and osmolarity had no significant effect on any of the sperm quality parameters. In conclusion, pyruvate maintains a higher quality and motility of sperm stored at 17 °C in PBS in comparison with a glucose-supplemented extender. Full article

This study provides a comparative analysis of the post-thaw sperm lipidomic profiles of Alpine and Spanish–Creole goat breeds to explore breed-specific differences in fatty acid composition and their implications for sperm function and reproductive efficiency. Lipids were extracted from cryopreserved semen samples of Alpine (n = 7) and Spanish–Creole (n = 4) mature bucks and subsequently analyzed by gas chromatography–mass spectrometry (GC-MS), with 21 fatty acids identified within the two breeds. Eight of these fatty acids, namely 13:0, 16:0, 18:0, 24:0, 14:1, 18:1 (cis-9), 24:1, and 18:2 showed significant differences (p < 0.05). The levels of 16:0, 18:0, 24:0, 18:1 (cis-9), 18:1, and 18:2 were higher in the Alpine breed, whereas the levels of 13:0, 14:1, and 24:1 were higher in the Spanish–Creole breed (p < 0.05). Of those, 16:0, 18:1 (cis-9), and 18:2 were both statistically and biologically significant (p < 0.05, FC > 2). Concentrations of the total fatty acids, total saturated fatty acids (Total-SFA), and total polyunsaturated fatty acids (Total-PUFA) were significantly higher in the Alpine breed, whereas the concentrations of the total cis-monounsaturated fatty acid (Total cis-MUFA) were significantly higher in the Spanish–Creole breed (p < 0.05). Network and pathway analyses revealed that 16:0, 18:1 (cis-9), and 18:2 contributed to the most central nodes of the lipidomic network, which may support membrane stability and cryotolerance. The lipidomic differences observed between breeds may be attributed to both genetic and environmental factors and may provide valuable tools for enhancing breeding strategies, artificial insemination programs, and sperm cryopreservation techniques. Full article

Lipopolysaccharide (LPS)-induced inflammation impairs sperm function; however, its impact on ejaculated rabbit sperm remains unexplored. This dose-response study aims to determine the LPS concentration that negatively affects sperm motility in vitro, while also providing the first identification of TLR4 localization on rabbit spermatozoa. Additionally, it evaluates malondialdehyde (MDA) levels in seminal plasma as an indicator of oxidative stress. Sperm motility was analyzed using computer-assisted sperm analysis (CASA) after incubation with increasing LPS concentrations (0, 50, 100, 200, 400, 600, and 800 µg/mL) at multiple time points (0, 1, 2, and 4 h). LPS doses ≥ 400 µg/mL significantly reduced progressive and non-progressive motility, as well as curvilinear velocity (all p < 0.001), while increasing the proportion of static spermatozoa (p < 0.05). Receiver operating characteristic (ROC) analysis identified 300 µg/mL as the threshold dose for motility decline. Immunofluorescence revealed TLR4 localization in the midpiece of sperm tails, with weak labeling in control samples and a marked increase after 4 h of incubation with 400 μg/mL LPS. MDA levels were assessed using the thiobarbituric acid reactive substances (TBARS) assay with a colorimetric kit, showing no significant effect of LPS treatment. No correlation was found between MDA and other semen parameters. ccThese findings identify TLR4 on rabbit sperm for the first time and establish a threshold LPS dose for future in vitro studies. Full article

In mammals, the pineal hormone melatonin is the most powerful pacemaker of the master circadian clock and is responsible for reproduction in seasonal breeders. It is also well known that melatonin and its metabolites play antioxidant roles in many tissues, including reproductive cells. Melatonin synthesis and secretion from the pineal gland occurs during scotophase (the dark phase during a day–night cycle), while its inhibition is observed during photophase (period of light during a day–night cycle). Short-day breeders, such as goats, are stimulated to breed in a manner dependent on high endogenous levels of melatonin. This hormone can be synthesized in various extra-pineal tissues, such as retina, gastrointestinal tract, ovaries, and testis, with its main function being as a local antioxidant, given that melatonin and its metabolites are potent scavengers of reactive oxygen and nitrogen species. Moreover, it has been reported that some functions of melatonin can be exerted through plasma membrane and intracellular receptors expressed in the male reproductive system, including germ cells, immature and mature spermatozoa. It has been shown that melatonin may enhance gamete cryosurvival mainly by its addition into the media and/or in exogenous melatonin treatments in several species. In the present review, the physiological effects of endogenous melatonin in mammals are described, with a deeper focus on caprine reproduction. Additionally, results from recent investigations on the roles of exogenous melatonin aimed at improving the reproductive efficiency of goat bucks are discussed. There are contradictory findings and a limited amount of research available in the field of goat sperm cryopreservation associated with the use of melatonin. Understanding and improving goat reproduction and production is essential for many marginalized human populations around the world who directly depend on goats to maintain and improve their lifestyle. Full article

This study explores how age and seasonal changes impact semen characteristics and reproductive behavior in Carpatina breed bucks. Males were divided into three age groups: young (14–23 months; L14), adult (3–4 years; L34), and older (5–6 years; L56). Scrotal biometry was determined using a measuring tape, and testicular volume was evaluated by fully submerging the testes in a water-filled container and measuring the displaced water. Semen analysis was conducted on samples collected each season, with volume, color, and acidity being assessed. The evaluation of specific semen characteristics (motility, sperm concentration, normal spermatozoa) was conducted using a Computer-Assisted Semen Analysis (CASA) system, and testosterone levels were measured in blood samples collected at the start of each season. Behavior and sexual reflexes were evaluated based on mating desire and the bucks’ reaction to the presence of females. Key findings indicate that testicular volume varies significantly with both age and season, with the most pronounced differences between younger bucks and the older groups, especially during autumn. Semen quality parameters such as ejaculate volume, sperm concentration, and motility also showed seasonal fluctuations, with younger bucks having lower sperm concentrations. Testosterone levels were observed to increase with age, peaking in autumn. Behavioral observations revealed that younger bucks exhibited less intense sexual activity, although this improved during autumn. Additionally, a significant correlation was identified between body weight and testicular volume in adult bucks (R = 0.942, p-value = 0.016 for L34; R = 0.797, p-value = 0.022 for L56), suggesting that age plays a crucial role in reproductive potential. Our findings highlight that, while bucks are capable of year-round reproduction, autumn provides optimal conditions for semen quality and reproductive performance. This research has valuable implications for optimizing breeding programs, contributing to genetic advancement, and improving management strategies in goat farming, especially within temperate continental climates. Full article

The effect of four extenders on buck semen quality parameters was examined during a 48 h liquid storage. Semen was collected from six Skopelos bucks and diluted in the following extenders, containing: soy lecithin (SL, OviXcell^®), plant phospholipids (PP, AndroMed^®), egg yolk lecithin (EY, Steridyl^®), or no phospholipids (basic extender). Samples were stored at 5 °C for 48 h and assessed at 0, 24 and 48 h for viability (eosin-nigrosin), acrosome integrity (SpermBlue^®), membrane functional integrity (HOST), mitochondrial function (Rhodamine 123/SYBR-14/PI) and motility parameters (CASA). No significant reduction in total or progressive spermatozoa motility and mitochondrial function was observed at 24 h, whereas they all dropped significantly at 48 h, in all extenders. Spermatozoa viability, cell membrane functionality and acrosome integrity dropped progressively (0 h > 24 h > 48 h) in all groups. No significant difference among extenders was observed concerning spermatozoa mitochondrial function. Overall, spermatozoa viability, cell membrane functionality and acrosome integrity were higher in the three commercial extenders, compared to the basic extender. SL and EY extenders (OviXcell^® and Steridyl^®, respectively) preserved viability more effectively than the PP extender (AndroMed^®). Total motility was higher in the PP extender, compared to the SL extender. Spermatozoa acrosome integrity tended to be higher in the EY extender compared to all the other extenders. Further investigation of the protective potential of different types of cryoprotectants on liquid buck semen storage is important. Full article

This study aims to investigate the impact of carvacrol and thymol on the quality of Beni Arouss buck semen stored in skim milk at 4 °C. Ejaculates were collected from eight Beni Arouss bucks weekly for 11 weeks, pooled, and then divided into three equal parts. Samples were diluted to 400 × 10⁶ sperm/mL in skim milk (control) and skim milk supplemented with a single dose of 200 µM carvacrol and thymol each. Evaluations of sperm motility, viability, abnormalities, membrane integrity, lipid peroxidation, and bacterial growth were conducted at 0, 6, 24, and 48 h of liquid storage at 4 °C. After 48 h of storage, the results indicate that the addition of carvacrol positively influences total and progressive motility and viability. However, it also leads to a decrease in lipid peroxidation and bacterial growth compared to the control group (p < 0.05). Thymol showed similar results to carvacrol, except for progressive motility (p > 0.05). Bacterial growth was negatively correlated with total and progressive motility and viability (p < 0.05), while no correlation between lipid peroxidation and these parameters was observed (p > 0.05). In conclusion, the addition of carvacrol and thymol to skim milk extender moderately improves the quality of Beni Arouss buck semen after 48 h storage at 4 °C due to its antimicrobial activity. Full article

Forty-four fallow deer bucks (10 months old; 22.9 ± 2.4 kg) were utilized to investigate the effects of immunocastration and amino acid supplementation on testes development. Immunocastrated bucks were administered Improvac^® at weeks 1, 8, and 20 of this study (control group: intact males). Starting at week 8, half of each sex received rumen-protected lysine and methionine (3:1) supplementation. At slaughter (week 37/39), body size, internal fat deposits, antler size parameters, testes weight, testes surface color, cauda epididymal sperm viability and morphology, and seminiferous tubule circumference and epithelium thickness were determined. Animals with larger body sizes, greater forequarter development, and antler growth also had greater testes development. Whilst the result of immunocastration on testes size is unexpected, testes tissue showed impaired development (atrophied seminiferous tubules), decreased sperm viability, and normal morphology. Testes tissue from immunocastrated deer was less red, possibly indicating reduced blood supply. Conversely, amino acid supplementation increased testes’ redness and sperm viability, and intact males fed amino acids showed the greatest seminiferous tubule development. Thus, immunocastration may be a welfare-friendly alternative for venison production. Whilst the results support findings from the literature that testes size is not a reliable indicator of immunocastration success, this warrants further investigation in deer over different physiological development stages. Full article

Spirulina platensis (SP) is a protein-rich dietary supplement that improves animal reproductive traits. This study investigated the effect of SP supplementation on puberty onset, semen characteristics, scrotal circumference (SC), libido, and hormone concentrations in Sahrawi and Jabbali bucks. The study was conducted in 36 bucks, divided into three groups (n = 6/group), for 70 days. The rations included the following: (1) Control feed (Con) with 14% crude protein and 11.97% MJ/kg DM energy; (2) Con with 2 g SP/head/day SP treatment (T1) and (3) Con with 4 g SP/head/day treatment (T2). The mean (±SEM) SC of both SP groups in the Sahrawi breed was significantly higher (p ≤ 0.05) compared to the Con. The mean of the semen volume significantly increased (p ≤ 0.05) in the SP group than in the Con group in both breeds. SP groups vs. Con groups had increased sperm concentration in Sahrawi bucks than Jabbali bucks. Mean serum luteinizing hormone (LH) and testosterone (Tes) concentrations in Jabbali bucks were significantly higher (p ≤ 0.05) in the SP groups compared to Sahrawi bucks. SP improved the SC, semen quality, libido, sperm concentration, and LH and Tes concentrations in both breeds. The results of the current study suggest that adding SP to the diet may have the ability to improve the semen quality of the local Omani bucks. Full article

Many dietary factors can affect sperm traits. We compared the effect of diets rich in pro-oxidant (flaxseed oil) and pro-atherogenic (coconut oil) substances without added antioxidants on semen traits, using the rabbit as an animal model. Thirty rabbit bucks (8 months old) were fed three diets for 150 days: CNT (control) a standard diet; HA (high-atherogenic) standard diet + 3% coconut oil, and HO (high-oxidizing) standard diet + 3% flaxseed oil. Semen samples were collected weekly for the evaluation of qualitative traits (kinetics, viability) and the oxidative damage (MDA and cytokines). Blood was collected at the start (T0) and end (T8) of the experimental period for the assessment of the oxidative damage (MDA and isoprostanoids), lipid profile, and testosterone. A worsening of sperm kinetics and viability was recorded in the HA group. Lipid oxidation in seminal plasma, as well as isoprostanoids in blood (F₃-IsoPs and F₄-NeuroPs), increased in both the HO and HA groups. A high level of TNF-α, a marker of inflammatory status, was recorded in the seminal plasma of the HA group. The resulting outcomes were mainly attributable to the different fatty acid profiles (SFA vs. PUFA) of the diets, which modulated an inflammatory/oxidative response. Full article

The supplementation of cryopreservation media with antioxidants improves the post-thaw quality and fertilizing ability of spermatozoa. To maximize the fertility of frozen–thawed buck spermatozoa, further research is required to overcome obstacles that have yielded controversial results and standardize protocols. In the present work, the effect of adding fumaric acid (a well-described antioxidant) to a soy lecithin semen extender on certain quality parameters of spermatozoa following freezing and thawing was examined for the first time. Five sexually mature Skopelos bucks were used, and ejaculates were collected with an artificial vagina. The semen samples (98 samples, five replicates) were diluted (400 × 10⁶ spermatozoa/mL) with OviXcell^®, supplemented with fumaric acid (0 mM, 2.15 mM, 10 mM or 30 mM), equilibrated (5 °C; 3 h), packed (0.5 mL straws), frozen and stored (−196 °C) until further processing. After thawing, the spermatozoa total and progressive motility (CASA), viability (eosin–nigrosin), membrane functional integrity (HOST), acrosome integrity (SpermBlue^®) and mitochondrial function (Rhodamine-123/SYBR-14/PI) were evaluated. Statistical analysis was performed with one-way ANOVA, followed by Duncan’s test; significance was set at 0.05. The addition of 2.15 mM fumaric acid improved (p < 0.05) spermatozoa viability, membrane functional integrity, acrosome integrity and mitochondrial function compared to all other concentrations. The addition of 30 mM fumaric acid decreased (p < 0.05) spermatozoa viability and mitochondrial function compared to all other concentrations. These results indicate a beneficial effect of a 2.15 mM fumaric acid addition to a soy lecithin extender on post-thaw buck spermatozoa quality. Further research is required to evaluate the in vivo fertility of frozen–thawed buck spermatozoa treated with fumaric acid, as well as to elucidate the mechanism of action of fumaric acid in spermatozoa. Full article

This study investigated the effect of different concentrations of ferulic acid (FA) on the quality of goat semen preserved at 17 °C. First, semen was collected from three black-headed goat bucks using an artificial vagina. Then, the mixed semen was diluted with basal dilutions containing different concentrations of FA (0, 25, 50, 100, and 200 μmol/L) and stored at 17 °C. Sperm total motility, plasma membrane integrity, acrosome integrity, reactive oxygen species (ROS) levels, malondialdehyde (MDA) content, and total antioxidant capacity (T-AOC) were measured during semen storage. The results showed that sperm total motility, plasma membrane integrity, and acrosome integrity were significantly improved in the 50 μmol/L FA group compared with the control group (0 μmol/L) on days 1–5, and the level of T-AOC significantly increased, while the contents of ROS and MDA significantly reduced. Meanwhile, the goats’ conception rate showed that supplementing semen with 50 μmol/L FA preserved at 17 °C for 3 days had no significant effect on fertility. Taken together, our findings suggest that adding 50 μmol/L FA in dilution at 17 °C can improve goat bucks’ semen quality. Full article

The effectiveness of rabbit-sperm cryopreservation is still below average compared to other domestic species. After the sperm cryopreservation process, post-thawing parameters like motility and membrane integrity are significantly compromised. The use of new extender constituents is an approach that can be used to improve the effectiveness of cryopreservation. Accordingly, we used honey (1.25, 2.5, 5, and 10%), coenzyme Q10 (100 and 200 μM), and β-carotene/α-tocopherol (500 μM/620 μM and 250 μM/310 μM) as candidate components for rabbit-sperm extenders during cryopreservation. Ejaculates from commercial adult rabbit bucks (n = 5) were cryopreserved using conventional freezing. Several post-thawing sperm parameters were assessed, including total motility, membrane integrity, viability, nuclear membrane integrity, acrosome reaction, and mitochondrial membrane potential and activation. Additionally, we performed hormonal analyses of the seminal plasma. Moreover, we analyzed the post-thawing levels of a molecular marker of sperm quality, proAKAP4, which was used in rabbits for the first time. Our findings showed that the 2.5% honey supplementation increased the post-thawing sperm motility (13.75 ± 3.75%) compared to the greater concentrations employed. However, the post-thawing motility was negatively affected by the coenzyme Q10 (0%, in both groups) but was not affected by the β-carotene/α-tocopherol supplementation (22 ± 18.15%, and 11.67 ± 10.17%). In conclusion, the cryopreservation protocols of this study did not help to maintain the sperm parameters after thawing. Further studies are required to identify novel protocols to mitigate the damage caused to rabbit sperm during cryopreservation. Full article

Spermatozoa are unique cells that carry a library of proteins that regulate the functions of molecules to achieve functional capabilities. Currently, large amounts of protein have been identified in spermatozoa from different species using proteomic approaches. However, the proteome characteristics and regulatory mechanisms of spermatozoa in bucks versus rams have not been fully unraveled. In this study, we performed a tandem mass tag (TMT)-labeled quantitative proteomic analysis to investigate the protein profiles in the spermatozoa of buck (Capra hircus) and ram (Ovis aries), two important economic livestock species with different fertility potentials. Overall, 2644 proteins were identified and quantified via this approach. Thus, 279 differentially abundant proteins (DAPs) were filtered with a p-value < 0.05, and a quantitative ratio of >2.0 or <0.5 (fold change, FC) in bucks versus rams, wherein 153 were upregulated and 126 were downregulated. Bioinformatics analysis revealed that these DAPs were mainly localized in the mitochondria, extracellular and in the nucleus, and were involved in sperm motility, membrane components, oxidoreductase activity, endopeptidase complex and proteasome-mediated ubiquitin-dependent protein catabolism. Specifically, partial DAPs, such as heat shock protein 90 α family class a member 1 (HSP90AA1), adenosine triphosphate citrate lyase (ACLY), proteasome 26S subunit and non-ATPase 4 (PSMD4), act as “cross-talk” nodes in protein–protein networks as key intermediates or enzymes, which are mainly involved in responses to stimuli, catalytic activity and molecular function regulator pathways that are strictly related to spermatozoa function. The results of our study offer valuable insights into the molecular mechanisms of ram spermatozoa function, and also promote an efficient spermatozoa utilization link to fertility or specific biotechnologies for bucks and rams. Full article