Search

Kaempferol (KAE) is a natural flavonoid with powerful reactive oxygen species (ROS) scavenging properties and beneficial effects on ex vivo sperm functionality. In this paper, we studied the ability of KAE to prevent or ameliorate structural, functional or oxidative damage to frozen-thawed bovine spermatozoa. The analysis focused on conventional sperm quality characteristics prior to or following thermoresistance tests, namely the oxidative profile of semen alongside sperm capacitation patterns, and the levels of key proteins involved in capacitation signaling. Semen samples obtained from 30 stud bulls were frozen in the presence of 12.5, 25 or 50 μM KAE and compared to native ejaculates (negative control-Ctrl N ) as well as semen samples cryopreserved in the absence of KAE (positive control-Ctrl C ). A significant post-thermoresistance test maintenance of the sperm motility ( p < 0.001), membrane ( p < 0.001) and acrosome integrity ( p < 0.001), mitochondrial activity ( p < 0.001) and DNA integrity ( p < 0.001) was observed following supplementation with all KAE doses in comparison to Ctrl C . Experimental groups supplemented with all KAE doses presented a significantly lower proportion of prematurely capacitated spermatozoa ( p < 0.001) when compared with Ctrl C . A significant decrease in the levels of the superoxide radical was recorded following administration of 12.5 ( p < 0.05) and 25 μM KAE ( p < 0.01). At the same time, supplementation with 25 μM KAE in the cryopreservation medium led to a significant stabilization of the activity of Mg 2+ -ATPase ( p < 0.05) and Na + /K + -ATPase ( p < 0.0001) in comparison to Ctrl C . Western blot analysis revealed that supplementation with 25 μM KAE in the cryopreservation medium prevented the loss of the protein kinase A (PKA) and protein kinase C (PKC), which are intricately involved in the process of sperm activation. In conclusion, we may speculate that KAE is particularly efficient in the protection of sperm metabolism during the cryopreservation process through its ability to promote energy synthesis while quenching excessive ROS and to protect enzymes involved in the process of sperm capacitation and hyperactivation. These properties may provide supplementary protection to spermatozoa undergoing the freeze-thaw process., Competing Interests: The authors declare no conflicts of interest. The funders had no role in the design of the study; in the collection, analyses or interpretation of data; in the writing of the manuscript; or in the decision to publish the results.

The objectives of this study were to compare the serum and seminal plasma pharmacokinetic profiles of florfenicol (FLO) and florfenicol amine (FLA) after the administration of FLO either by IM or SC routes in beef bulls. Four clinically healthy Hereford bulls underwent a comprehensive physical exam, including breeding soundness examination, CBC, and chemistry profile panel. Bulls were healthy and classified satisfactory potential breeders. In one group (n = 2), a single dose of FLO was administered SC in the middle of the neck at a dose of 40 mg/kg of body weight. In the second group (n = 2), a single dose was administered IM in the muscles of the neck at a dose of 20 mg/kg. Concentrations of FLO and FLA in serum and seminal plasma were determined by ultra-high-performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS). Blood and semen samples were collected before the administration of FLO and at 12, 24, 36, 48, 72, 96, 120, 144, and 168 h after injection. The blood was collected from the coccygeal vessels, and semen was collected by electroejaculation. All samples were immediately refrigerated, processed within the first hour after collection, and finally stored at -80 °C. The mean level of total FLO in serum was higher when administered by the SC route (1,415.5 ng/mL) than by the IM route (752.4 ng/mL; P = 0.001). Differences were observed between the percentage of FLA in serum (1.8%; ranging from 1.3 to 2.9) and in seminal plasma (27.5%; ranging from 15.9 to 34.2; P = 0.0001). The mean level (±SD) of FLA was higher in seminal plasma compared to serum (467 ± 466 ng/mL and 18 ± 16 ng/mL, respectively; P = 0.001). The mean level of total FLO in seminal plasma was 1,454.8 ng/mL for the SC route and 1,872.9 ng/mL for the IM route without differences between the two routes (P = 0.51). Differences in the mean level of total FLO between serum and seminal plasma were detected (1,187 ± 2,069 ng/mL and 1,748 ± 1,906 ng/mL, respectively; P = 0.04). From the present investigation, it was concluded that FLO is a suitable antibiotic based on its pharmacokinetic attributes and may be employed for the treatment of bull genital infections when its use is indicated. To study the pharmacokinetics of FLO in seminal plasma, the analysis of FLA should be incorporated., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Semen morphology evaluation in the field should always be performed at 1000× with oil immersion. The development of a spermiogram will aid the practitioner to interpret potential fertility of semen at the time of sampling as well as determine potential causes of an abnormal spermiogram. Bulls, which experience stress or impairment of thermoregulation of the testes for any reason, often experience a transitory decrease in the quality of sperm morphology. This can be recognized by a sequence of appearances of morphologic defects coupled with a thorough patient history., (Copyright © 2023 Elsevier Inc. All rights reserved.)

This study evaluated the effect of climate change on andrological parameters of beef bulls raised under tropical, subtropical, and temperate conditions. Bull ejaculates were collected to evaluate seminal quality parameters, sperm membrane integrity, and redox status (SOD; GPx; GSH; GRx; CARB; DCF; and SOD/GPx ratio). Bulls located in the temperate region showed a higher sperm motility rate and percentage of viable sperm (P < 0.05). When evaluating regions independently, we observed a lower GPx activity from animals in the tropical region (P < 0.05). In contrast, we found that SOD and GRx activities, GSH content, and CARB oxidative levels were higher in the tropical region, while oxidation values of DCF were lower (P < 0.05). Braford bulls showed higher CARB and DCF levels (1.23 ± 0.61 nmol/mg and 1453.60 ± 828.63 nmol/mg, respectively) compared to Hereford bulls (1.00 ± 0.43 nmol/mg and 1138.70 ± 423.24 nmol/mg, respectively) in the temperate region. However, Nellore bulls showed higher DCF levels (650.50 ± 401.53 nmol/mg) than Braford bulls (409.40 ± 286.97 nmol/mg). In addition, the SOD/GPx ratio was lower in Braford (12.44 ± 7.64 U/mg) compared to Nellore bulls in tropical conditions (87.25 ± 2.83 U/mg). A positive correlation was found in temperate conditions between DCF levels, SOD, and GRx activities (0.51, 0.58; P < 0.01, respectively), as well as in subtropical conditions between DCF levels and GRx activity (0.53; P < 0.01). A negative correlation between the temperature-humidity index and CARB content was found in subtropical and tropical regions (-0.44; P < 0.01). We concluded that Braford breeds showed lower seminal motility, DCF contents and SOD/GPx ratios compared to Nellore bulls in tropical climate conditions. Finally, in temperate environmental conditions, Braford bulls also showed lower seminal motility but higher levels of CARB and DCF contents compared to Hereford bulls. Therefore, the existence of climatic differences between the temperate and tropical regions evaluated affected Braford bulls' seminal motility and seminal redox homeostasis., Competing Interests: Declaration of competing interest The authors declare that there is no conflict of interest that could be perceived as reducing the impartiality of the research reported., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Seminal plasma (SP) contributes to sperm physiology and metabolism, prevents premature capacitation, and protects sperm against oxidative stress. In order to evaluate the impact of heat stress in the semen of tropically adapted Brangus breed and in their seminal plasma proteome, we studied the effects of scrotal insulation for 72 h. Semen samples from six bulls, between 7 and 8 years of age, were collected prior to scrotal insulation (pre-insulation), and at 4 and 11 wk after insulation. Seminal plasma samples were analyzed by 2D SDS-PAGE and liquid chromatography coupled with mass spectrometry (LC-MS/MS). Insulation caused decrease in vigour, gross and total motility after 4 wk of scrotal insult (P < 0.001). Total defects in sperm were higher after 4 wk compared to pre-insulation and 11 wk after scrotal insulation (P < 0.001). The analysis of the 2D protein profile of the SP resulted in the identification 183 unique protein spots in all gels evaluated. There was no difference in mean number of protein spots amongst time points. Eight protein spots were more abundant in SP after scrotal insulation, returning to the same expression level at 11 wk post-insulation. One spot had higher abundance at 11 wk post-insulation, and one spot had decreased abundance 4 wk after insulation. The ten protein spots with differential abundance amongst time points were identified as Seminal plasma protein PDC-109, Seminal plasma protein A3, Seminal plasma protein BSP-30 kDa, Spermadhesin-1 and Metalloproteinase inhibitor 2. The validation of these five proteins as biomarkers for thermal testicular stress in Brangus breed would allow the development of new biotechnologies that could improve bovine semen analysis in breeding systems in tropical and subtropical conditions. A close association between the identified BSP and Spermadhesin-1 was evidenced in protein-protein interaction analysis. Based on gene ontology analysis, variation in sperm function after insulation could be explained by variation in the expressed proteins in the SP. Further studies are required to verify if these proteins could be used as biomarkers for the identification of bulls with increased seminal resistance to heat stress in Brangus breed., Competing Interests: Declaration of competing interest The authors declare that there are no conflicts of interest that may have influenced that discussion presented herein., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Sperm are highly specialized compartmentalized cells, with unique compositional, morphological and functional properties, including a plasma membrane that undergoes dynamic protein remodeling and surface modifications. Seminal plasma is a highly complex biological fluid containing proteins, amino acids, enzymes, fructose and other carbohydrates, lipids, major minerals and trace elements. Seminal plasma proteins are involved in regulation of osmotic pressure and pH of seminal plasma, transport of ions, lipid and hormones. The objective was to compare sperm and seminal plasma proteomes of bulls with differing fertility and to relate differences to biological processes. Semen was collected from bulls with high or low fertility (4 bulls in each category). Sperm and seminal plasma proteins were isolated, purified, subjected to 2-D gel electrophoresis, protein identification and ontology. In sperm and seminal plasma, binder of sperm proteins (BSP)-1, -3 and -5, and spermadhesin-1, ALB, TIMP, AKI and PEBP1 were higher for high-versus low-fertility bulls (P < 0.05), whereas proteins CLU, CCT5 and 8, ELSPbP1, and PSMA6 were more abundant in sperm and seminal plasma of low- versus high-fertility bulls (P < 0.05). Further, HSP90, ZFP34, IFNRF4, BCL62, NADHD, TUBB3 and Histone H1 were in greater abundance in sperm of high- compared with low-fertility bulls. The two key biological processes of proteins differentially expressed in high- and low-fertility bulls were metabolic processes and biological regulation. The most prominent molecular functions for proteins that differed are binding, catalytic and receptor activities. The main cellular components for proteins that differed are cellular, extracellular, and plasma membrane. Since protein content differed in high- versus low-fertility bulls, we inferred that the efficiency of associated sperm functions that are necessary for fertility may also differ between high- and low-fertility semen. In conclusion, differences between high- and low-fertility bulls regarding abundance of sperm and seminal plasma proteins likely contributed to differences in fertility., (Copyright © 2018 Elsevier Inc. All rights reserved.)

A total of 27 seminal plasma samples from cattle-breeding farms or semen centres located in Minas Gerais, Brazil, previously negative by serological and tested positive for Brucella spp. with primer specific for the amplification of the gene virb5 by polymerase chain reaction (PCR) were analysed for the detection of Brucella abortus DNA by PCR. It was found that nine samples (33.33%) contained B. abortus B19 strain DNA, two (7.40%) contained B. abortus DNA and five (18.51%) contained both DNA. The larger number of samples with B. abortus B19 strain DNA would explained by the environmental contamination by vaccinated females with persistent excretion or some illegal vaccination process. It is first reported of male bovines detected with both DNA., (© 2017 Blackwell Verlag GmbH.)

The paraoxonases types 1, 2 and 3 (PON1, PON2 and PON3, respectively) are enzymes that degrade lipid peroxides, preventing oxidative damages relevant for male reproductive function. This study determined the expression of those three paraoxonases in reproductive tissues of bulls and evaluated correlations among the activity of PON1 in the serum and seminal plasma with breeding soundness parameters in bulls. The expression of PON1, PON2 and PON3 was characterised by RT-PCR in samples of testicular parenchyma, vesicular glands and epididymis collected from three slaughtered bulls. All three paraoxonases were expressed in the testicular parenchyma, PON2 and PON3 were both expressed in the epididymis head and PON3 was also expressed in the epididymis tail. The PON1 activity was determined in samples of serum and seminal plasma from 110 bulls submitted to breeding soundness evaluation. There was a strong correlation (r = .90) between the activity of the PON1 in both serum and seminal plasma (p < .0001). The PON1 activity in the seminal plasma was positively correlated with ejaculate's colour, sperm mass activity (p = .04), motility, vigour and viability (all p < .01). Thus, PON1 may be a potential marker for sperm motility and viability in bulls., (© 2017 Blackwell Verlag GmbH.)

Semen contaminated with microorganisms can disseminate serious diseases including brucellosis. The objectives of this study were to detect Brucella-specific antibodies and Brucella abortus DNA in samples of blood and fresh semen from 100 animals older than 20 months. The samples were collected on farms and in semen collection and processing centers (CCPS). The serum samples were evaluated by Rose Bengal test (RBT). B. abortus DNA was detected by a polymerase chain reaction (PCR) using BAB and IS771 primers. The difference between the vaccine field strain was identified using ery-1, ery-2, and ery-3 primers, using the hemi-nested PCR method. No anti-B. abortus antibodies were detected in the serum samples. Out of the total semen samples, 68% (68/100) presented amplifications of the B. abortus genes. All (68/68) were identified as B19 strain of Brucella abortus vaccine. It was concluded that even bulls that are seronegative for brucellosis can eliminate the bacteria in the semen. The presence in the DNA of the B19 vaccine strain should be investigated for a better understanding of the epidemiological importance of this strain in these animals.

The aim of the present study was to examine the effects of feeding alpha-linolenic (ALA) acid on fatty acid composition and quality of bovine sperm and on antioxidative capacity of seminal plasma. Nine bulls (ALA bulls) were fed with 800 g rumen-resistant linseed oil with a content of 50% linolenic acid and eight bulls with 400 g palmitic acid (PA bulls). Sperm quality was evaluated for plasma membrane and acrosome intact sperm (PMAI), the amount of membrane lipid peroxidation (LPO), and the percentage of sperm with a high DNA fragmentation index (DFI). Fatty acid content of sperm was determined using gas chromatography. Total antioxidant capacity, glutathione peroxidase, and superoxide dismutase activity were determined in seminal plasma. Feeding ALA increased (P < 0.05) the docosahexaenoic acid (DHA) content in bulls whereas in PA bulls did not change. PMAI increased after cryopreservation in ALA bulls as well as in PA bulls during the experiment period (P < 0.005). LPO of sperm directly after thawing did not change during the study period in ALA group, but decreased in PA group (P < 0.006). After 3h of incubation LPO increased in the ALA group (P < 0.02), while LPO did not differ between phases within groups. In conclusion, feeding of neither saturated nor polyunsaturated fatty acids affect the antioxidant levels in seminal plasma. Both saturated as well as polyunsaturated fatty acids had positive effects on quality of cryopreserved bovine sperm, although the content of docosahexaenoic acid in sperm membranes increased only in ALA bulls., (Copyright © 2015 Elsevier B.V. All rights reserved.)

The objective of this study was to compare the plasma (PL) and seminal plasma (SP) pharmacokinetic profile of ceftiofur (CEFT) and desuroylceftiofur acetamide (DFCA) after administration of CEFT crystalline-free acid (CCFA) by SC route in two sites of the ear in beef bulls. Four clinically healthy Hereford bulls received a comprehensive physical exam and subsequently a breeding-soundness examination, CBC, and chemistry profile panel. All bulls were diagnosed healthy and satisfactory potential breeders. In one group (n = 2), a single dose of CCFA was administered SC route at the base of the ear (BOE) at a dose of 6.6 mg/kg of body weight. The second group (n = 2) was also administered by SC route in the middle third of the posterior aspect of the ear (MTE). The concentrations of CEFT and DFCA in PL and SP were determined by a high-performance liquid chromatography mass spectrometry (HPLC-MS). Blood and semen samples were collected before the administration of CCFA and at 12, 24, 36, 48, 72, 96, 120, 144, and 168 h after injection. No levels of CEFT were detected in PL and only in 20 of the 40 SP samples (P = 0.0001). The mean level of CEFT in SP was 0.11 % in comparison with the DFCA level. DFCA was found in all PL and SP samples. Therefore, DFCA was chosen to be utilized in the study of the pharmacokinetics parameters both in PL and SP. There were no differences in the mean PL levels of DFCA for the two sites of SC administration between the BOE (102.9 ± 78.9 ng/mL; X ± SD) and to MTE (116.1 ± 70.2 ng/mL; P = 0.58). The mean SP levels of DFCA after administration in the BOE was 857 ± 747 ng/mL, and for the MTE was 549 ± 488 ng/mL without differences between both sites (P = 0.15). The mean level of DFCA in PL was 109.5 ± 74.0 ng/mL, which was lower than the mean SP levels of 695 ± 103 ng/mL (P = 0.001). Moreover, the PL peak DFCA concentration (C max) was 229 ± 46 ng/mL at 36.0 ± 29.4 h (T max) post-administration. The SP C max was 1851 ± 533 ng/mL at 30.0 ± 28.6 h (T max) post-administration. The C max between PL and SP were distinctive (P = 0.004) without any differences in T max between PL and SP (P = 0.60). The terminal half-life for PL DFCA (47.4 ± 29.3 h) was not different than in SP (53.1 ± 23.6 h; P = 0.77). The PL area under the curve concentration time from the first to the last sample (AUC 0–last) was 18,984 ± 4841 ng/mL/h, which was significatively smaller compared with 125,677 ± 59,445 ng/mL/h for SP AUC 0–last (P = 0.04). The PL mean residence time from the first to the last sample (MRT 0–last) was 69.7 ± 15.1 h, and it was similar than for SP of 66.5 ± 7.7 h (P = 0.69). From the present investigation, based in its pharmacokinetic features, it was concluded that CCFA should be an appropriate antibiotic that could be used for the treatment of bull genital infections when its indication is properly outlined. To study the pharmacokinetics of CCFA in SP, DFCA metabolite was appropriated. [ABSTRACT FROM AUTHOR]

Breeding soundness evaluation (BSE) is the best methodology to estimate the fertility potential of future bulls and performing indirect selection for their fertility. However, the outcome of the BSE is influenced by several factors, including genetics, environment, and BSE guidelines. Herein, in this retrospective study, our first aim was to characterize the reasons for failure in 46,566 BSE from 2-year-old beef Bos indicus bulls (Nellore) born from 1997 to 2018. Our second aim was to determine whether or not BSE was associated with reproductive potential improvement of the bulls over the years. Due to changes in the BSE criteria, we used the same dataset, but only bulls born from 2002 to 2018 were included resulting in 35,856 BSE. For the second aim, the effect of the year and farm were included in the model of the multivariate logistic regression. We also determined if the main reasons for BSE failure decreased over time. Bulls were classified as approved (satisfactory potential breeders and qualified for natural breeding service) and not approved (deferred and unsatisfactory potential breeders). The reasons for BSE failure in Nellore bulls were poor semen quality (53.1 %) and physical defects (46.9 %), with the main physical defect being testis abnormalities (19.7 %). The overall percentage of bulls approved each year was 87.1 %, with no improvement over the years of study. However, the percentage of approved bulls at the first BSE increased over the years (P < 0.05). This increase was evident by a reduction in the difference between the overall percentage of the bulls approved vs the percentage of bulls approved at the first BSE. Furthermore, there was an increase in the percentage of bulls classified as satisfactory potential breeders in the BSE and an evident decrease in the percentage of bulls qualified only for natural breeding service (P < 0.05). In addition, an increase of the scrotal circumference (SC) of the herd was found (P < 0.05). These results indicate the overall quality of the bulls improved over the years. To associate and identify the main sperm abnormalities, 3461 not approved bulls were clustered. The most frequent defects were strongly coiled tail spermatozoa, proximal droplets, and acrosomal defects. Overall, there was no change in the frequency of bulls not approved by the sperm morphology nor the frequency of the main sperm abnormalities over the years. Nevertheless, the frequency of the defects remained very low, implying they were controlled. Additionally, abnormalities in the testis decreased over the years and was associated with the increase in the SC of the herd and a decrease of culled bulls due to low SC. In conclusion, this study demonstrates that there is an association between implementation and use of BSE with improvements in the reproductive quality of future generation bulls. • Records of 20 years and 46,566 BSE from a seedstock herd in Brazil were investigated. • About 14 % of the bulls fail to be approved in the BSE at two years of age. • Semen quality (53 %) & physical defects (47 %) were the most common causes of failure. • Testicular abnormalities decreased, & scrotal circumference increased over the years. • BSE was associated with increased percentage of bulls approved at first BSE over years. [ABSTRACT FROM AUTHOR]

The correlation between peripheral and seminal hormones and biochemical parameters with sperm kinematics across seasons in buffalo bulls were studied. Semen from buffalo bulls (n = 13) during different seasons viz. summer, comfort (spring and autumn) and winter was collected. Sperm kinematics of ejaculates (n = 39) (three ejaculates per bull) were carried out during each season and simultaneously blood (10 mL) was collected and serum was separated for hormones (leptin, testosterone and kisspeptin) and biochemical [heat shock protein 70 (HSP70), ascorbic acid and total antioxidant capacity] estimation. Total motility (TM, %), progressive motility (PM, %) and rapid motility (RM, %) showed significant differences across seasons with the highest TM, PM and RM during winter. HSP70 was higher in seminal plasma levels during summer and TAC was higher in serum than seminal plasma during all seasons. In conclusion, seminal leptin and ascorbic acid showed an association with sperm kinematics across seasons in buffalo bulls. [ABSTRACT FROM AUTHOR]

This study aims to compare the efficacy of computer‐assisted sperm analysis (CASA) and smartphone‐applied sperm analysis (SASA) in assessing the quality of frozen–thawed bull semen. A total of 75 straws (n = 75) semen samples were used from different production batches of five Holstein bulls. The semen analyses were conducted in three groups: Group I (CASA‐37°C), semen samples were evaluated using the CASA system at 37°C (n = 25); Group II (SASA‐25°C), semen samples were assessed using the SASA system at a temperature of room heat (25°C) (n = 25); and Group III (SASA‐37°C), semen samples were evaluated using the SASA system at 37°C (n = 25). The frozen–thawed bull semen samples were analysed in terms of total motility (TM), progressive motility (PM), immotile, velocity average path (VAP), velocity curve linear (VCL), velocity straight line (VSL) and sperm concentration. There was no significant difference between the groups in terms of spermatozoa concentration (p >.05). However, significant differences among the groups were observed for total motile spermatozoa values (p <.001). Values of progressive motile spermatozoa were lower in Group I and Group II compared to Group III (p <.001). The immotile spermatozoa values were significant between the groups (p <.001) and were found to be proportional to total motile spermatozoa values. Additionally, the VAP, VCL and VSL values were comparable between Group II and Group III, but lower when compared to Group I. In conclusion, the results of the study demonstrate that the Sperm Cell™ system can accurately analyse the concentration of frozen–thawed bull semen. The analyses performed at room temperature indicate a parallelism between the PM value and CASA results. However, it is thought that SASA devices require a series of standardization studies in different semen extenders, different sample concentrations and different animal species, analogous to the standardization evolution process of CASA devices in semen analysis. [ABSTRACT FROM AUTHOR]

This study investigated the effect of season, age and period on semen traits in buffalo bulls. Data collected during the year 2010–2021 for seven semen traits viz. ejaculate volume (VOL), sperm concentration (SPC), mass activity (MA), initial motility (BFM), post-thaw motility (PTM), number of sperms per ejaculate (NSP) and number of motile sperm (NMSP) from Murrah buffalo bulls (n = 45; aged: 24–75 months). A general mixed model was applied to obtain the R2 value which was the proportion of variation in semen variable. With study period, the highest SPC was obtained during 2012; with the season, the highest VOL (ml) in hot humid and the highest SPC during the hot-dry season and with age, higher VOL, SPC, NSP and NMSP was obtained in older bulls. This study showed that factors i.e. period, season and age had a significant effect on semen traits viz. VOL, MA, SPC, BFM, PTM, NSP and NMSP in buffalo bulls. [ABSTRACT FROM AUTHOR]

Scrotal circumference (SC) is the main indicator of sperm production potential, this dimension is used to increase the reproductive capacity of bulls. SC can be used as a criterion for fertility selection in cattle farms. The objective of the research is to review the importance of reproductive evaluation of the bull and the correlation of scrotal circumference with semen quality. A bibliographic review was carried out to demonstrate the main advantages of testicular size and weight in young bulls since it is highly correlated with scrotal circumference, which is the main indicator of sperm production potential. It was concluded that selecting young bulls with a good scrotal circumference has benefits, since they produce more semen of higher quality compared to bulls of the same age, but with smaller testicles. [ABSTRACT FROM AUTHOR]

Background: The choice of superior herd sires is essential for genetic improvement in dairy cattle, with sperm quality serving as a key factor. Bull semen’s superior qualities are essential for accelerating genetic improvement through AI. These characteristics are affected by several factors, including the environment, management techniques, physiological condition and hereditary factors. This study involved in evaluating genetic and non-genetic factors influencing seminal attributes. Methods: Data on 1,85,413 ejaculates from nine genetic groups viz. Jersey, Holstein Friesian, crossbred Jersey, crossbred Holstein Friesian, Bargur, Kangayam, Pulikulam, Umblachery and Red Sindhi were collected from four frozen semen stations of Tamil Nadu State. Semen production data viz. ejaculate volume (mL), spermatozoa concentration (million per mL), initial motility (percentage), post-thaw motility (percentage), total initial motile spermatozoa and total post-thaw motile spermatozoa were also examined for various genetic and non-genetic factors affecting them using linear mixed model with repeated measures. Result: The overall estimated marginal means for Volume of ejaculate, Concentration of spermatozoa, Initial motility, Total initial motile spermatozoa per ejaculate, Total doses per ejaculate, Post-thaw motility and Total post-thaw motile spermatozoa per ejaculate were 3.11±0.11 (mL), 963±30.60 (106 /mL), 79.50±1.29 (per cent), 1847±118 (106 ), 151.00±7.20, 51.00±0.42 (per cent) and 1535±80.20 (106 ) respectively. The effect of all genetic and non-genetic factors (farms, ejaculates, period, seasons, age) were observed to be significantly influencing the seminal traits considered in the study. However, the estimated marginal means of each trait displayed varied ranges of mean against non-genetic factors. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Sperm rheotaxis is a sperm guidance mechanism that helps to guide and select high-quality sperm cells within the female reproductive tract. Semen is usually evaluated using either the traditional subjective method of evaluation or computer assisted sperm analysis (CASA). These methods provide information about sperm concentration, viability and motility parameters and ignoring sperm ability to travel inside the female reproductive tract. Our goal was to detect the individual variations between different sires through evaluation of post thawed frozen semen using sperm rheotaxis. We studied sperm rheotaxis and sperm kinematics inside microfluidic platforms together with subjective semen analysis (motility, viability, and sperm morphology) in post-thawed bull frozen semen in different sires. The results showed that the positive rheotaxis (PR) was higher in the postthawed frozen semen of some bulls (P < 0.05) than in others. Our results also revealed that the bulls with the higher PR% have significantly higher straight-line velocity (VSL) and subjective analysis parameters (motility and viability) (P < 0.05) than bull with the lower PR. Furthermore, PR was positively correlated with VSL (r = 0.67, P < 0.0001) and with subjective motility and viability (r =0.57, P = 0.007 and r = 0.49; P= 0.02, respectively). Thus, we concluded that sperm rheotaxis should be used as a new parameter in evaluation of post-thawed frozen semen quality in bull. [ABSTRACT FROM AUTHOR]

Background: Sexual behaviour is an intricate process, controlled by the endocrine constitution of an animal and influenced by the social environment, sensory capability and sexual stimuli. Variations in temperature associated with global warming are startling for fertility of animals. The objective of the present study was to assess the seasonal variation in sexual behaviour of Deoni (Bos indicus) breeding bulls. Methods: A total of six mature Deoni bulls, maintained for artificial insemination at Livestock Research Center, Southern Regional Station of ICAR-NDRI, Bengaluru, were monitored for sexual behavior during the semen collection at weekly intervals throughout the year using standard techniques. The period of study was divided into three seasons i.e., winter (November to February), summer (March to June) and rainy (July to October). Result: The season had a non-significant (P>0.05) effect on sexual behavior except dismounting time in Deoni bulls. The libido score (0-10), reaction time (seconds) and the total time taken in mounting (seconds) were non-significantly (P>0.05) higher during winter (7.50±0.23, 42.00±4.8, 44.00±4.8, respectively) as compared to the other seasons. The protrusion score (0-4) and the intensity of thrust (0-4) were non-significantly (P>0.05) higher during summer (2.60±0.14 and 2.50±0.13) as compared to the other seasons. The dismounting time (seconds) was significantly (P<0.05) higher during summer (2.90±0.16) as compared to the other seasons. It can be concluded that Deoni bulls had good sexual behavior throughout the year, however, bulls showed better sexual behavior except for dismounting time during winter as compared to the other seasons. [ABSTRACT FROM AUTHOR]

Artificial insemination (AI) centres select bulls as calves according to their genetic breeding values and raise them until the first semen collection; yet, a high dropout rate of reared bulls is a problem for AI centres. Potential hormonal indicators of bull sexual maturation (cortisol, dehydroepiandrosterone (DHEA), testosterone, oestradiol, insulin‐like growth factor 1 (IGF‐1)) were observed and evaluated in relation to the performance parameters to perhaps identify candidate biomarkers allowing an early selection of bulls as suitable sires. Blood samples from 102 German Holstein calves at 4 ± 1, 8 ± 1 and 12 ± 2 months of age from six AI centres were analysed using validated immunoassays for cortisol, DHEA, testosterone, oestradiol and IGF‐1. Semen analyses included native and thawed diluted semen. Bulls were classified at the first semen collection into groups with good versus poor performance (GP vs. LP). After 2 years, the subsequent differentiation was done in high (HPP), medium (MPP) and low performance persistency (LPP). Age at first semen collection was an important factor for sperm quality. Cortisol concentrations decreased with age, but the cortisol/DHEA ratio decreased with age only in GP bulls (p <.05). Oestradiol and testosterone concentrations both correlated with libido behaviour (p <.05). Testosterone and IGF‐1 concentrations were higher at the time of first semen collection in GP bulls and increased with age (p <.05). In conclusion, testosterone and IGF‐1 concentrations at first semen collection are associated with performance at first semen collection and future performance persistency, and might be useful early biomarkers for consistent sperm producing bulls on AI centres. [ABSTRACT FROM AUTHOR]

Dimensions of linear type traits facilitate selection of livestock for breeding and rearing. To date, use of linear type traits for selection of breeding bulls is highly concentric to scrotal circumference (SC), with probable overlook to other important traits. Present study reported the importance of various gonadal linear type traits on spermatozoa production, age‐related changes in gonadal linear type traits of bulls and predictive ability of these traits on bulls' reproductive potentials. Among all gonadal traits, testicular density (TD), scrotal volume (SV), paired testicular weight (PWT) and SC were found most important predictor variables in order, which can discriminate between good/poor breeding bulls, that is, produced frozen semen doses (FSD) or not. Dimensions of gonadal traits increased significantly up to 36 months age and thereafter, development became slow and negligible. In contrast, TD decreased by 30%, 51%, 64%, 68% and 71% at 12, 24, 36, 48 and >49 months age, respectively, from its base value at 6 months. Bulls of lower TD (≤0.88 g/cm3) had significantly higher ejaculate volume (+9%), sperm motility, sperm concentration (+100 million/mL) and sperm output (+26%)/ejaculate as compared to bulls of higher TD (>0.88 g/cm3). Discriminant function was developed using TD, SV, PWT and SC to identify bulls of superior reproductive potentials. It was concluded that among the investigated traits, TD was the strongest to discriminate between FSD and Non‐FSD bulls. Therefore, our findings suggested that TD could be more potential trait than SC for dairy bulls' breeding soundness evaluation and assessment of reproductive ability. [ABSTRACT FROM AUTHOR]

The present investigation was carried out to study the semen characteristics of Vechur bulls. A total of 36 ejaculates collected from six Vechur bulls were studied. The overall mean ejaculate volume, colour, pH, mass activity, progressive sperm motility and total seminal plasma protein concentrations were analysed. The mean ejaculate volume noted was 2.26 ± 0.36 ml, colour of semen ranged from milky to thick milky, pH was 6.87 ± 0.02, density from DDD to DDDD, mass activity +++ to ++++ and sperm progressive motility was 78.1 ± 1.05 %. Significant differences in ejaculate volume, mass activity, progressive sperm motility and live sperms were observed among the bulls. The mean protein content of seminal plasma was 84.10 ± 2.73 mg/ml. On SDS-PAGE analysis, 20 proteins bands of varying intensities were observed within the range of 10-180 kDa and preponderance of lower molecular weight proteins was recorded. [ABSTRACT FROM AUTHOR]

Semen cryopreservation is an important tool that has massively contributed to the progression of animal reproduction, especially in cattle. Nonetheless, a large part of the sperm population suffers from cryostress and loses fertility during the process. Although bovine semen cryopreservation is more advanced than any other species, there are still some missing links in the technology knowledge. The aim of the current study was to detect the effect of cryopreservation steps on sperm rheotaxis. Semen samples were collected from sex bulls and analyzed inside a microfluidic platform with CASA after each step of cryopreservation, including control, dilution with yolk citrate, cryoprotectant addition, and cooling or freezing. The results showed that positive rheotaxis % (PR) was not affected during cryopreservation. On the contrary, the sperm kinematics of the positive rheotactic sperm undergo significant changes, as velocity parameters (VCL, VSL, and VAP) were lower in both the cryoprotectant adding and cooling/freezing steps than in the control and yolk citrate dilution steps, while progression parameters (LIN and BCF) were higher in the cryoprotectant and cooling/freezing steps than in the control and yolk citrate dilution steps. Beside these results, an interesting phenomenon of sperm backward positive rheotaxis has been observed. The results of backward sperm rheotaxis samples revealed a significant decrease in PR%, while all sperm kinematics except BCF were significantly higher than normal rheotaxis samples. Based on these results, we conclude that positive rheotactic sperm cells are the elite of the sperm population; however, they still get some sublethal cryodamage, as shown by alterations in sperm kinematics. We also suggest that the sperm-positive rheotaxis mechanism is a mixture of an active and passive process rather than a passive physical one. [ABSTRACT FROM AUTHOR]

Objectives: Bovine seminal plasma proteins perform several functions related to sperm function. Changes in the expression pattern or abundance of seminal proteins are related to changes in the fertilizing capacity of bulls. Considering the role of seminal plasma proteins in sperm function and animal reproduction, we investigated changes in the protein abundance profile in response to sperm morphological changes using a proteomic approach. Datadescription: In our present investigation, we employed liquid chromatography coupled with mass spectrometry to elucidate the proteomic composition of seminal plasma obtained from Nellore bulls exhibiting varying percentages of sperm abnormalities. Following semen collection, seminal plasma was promptly isolated from sperm, and proteins were subsequently precipitated, enzymatically digested using porcine trypsin, and subjected to analysis utilizing the Acquity nano UHPLC System in conjunction with a mass spectrometer. This dataset encompasses a total of 297 proteins, marking the inaugural instance in which a comparative profile of seminal plasma proteins in young Nellore bulls, categorized by their sperm abnormality percentages, has been delineated using LC-MS/MS. The comprehensive nature of this dataset contributes pivotal proteomic insights, representing a noteworthy advancement in our understanding of the reproductive biology of the Nellore breed. [ABSTRACT FROM AUTHOR]

Spermatozoa can experience negative changes when subjected to freezing and thawing, including lowered motility, viability and acrosome response. Herein, the effects of different concentrations of soybean lecithin nanoparticles on cryopreserved Holstein bull semen were examined. Semen was collected, cryopreserved and utilized for sperm kinetic parameter analysis following dilution, equilibration and thawing with 0.5% soybean lecithin (E1), the control extender, and 0.75% (E2), 0.5% (E3), 0.25% (E4) and 0.125% (E5) of lecithin nanoparticles. Results revealed that following dilution, the progressive motility (PM) at E3, E4 and E5 of lecithin nanoparticles was higher (p <.05) than it was for E2. After equilibration, compared to the E1, E2, and E3 values, the PM, vitality, normal morphology, membrane integrity and intact acrosome values at the E5 were consistently greater (p <.05). Comparing the percentages of intact acrosome and membrane integrity at E2 and E3 to E4 and E5, a substantial decrease (p <.05) was seen. Following thawing, the percentage of PM improved at E2 and E5, even though their mean PM values were similar (p >.05) compared to E1, E3 and E4. Vigour and progression parameters of sperm (DAP, DCL, DSL, VAP, VCL, VSL and STR) at E5 were higher (p <.05) than those at E1, E2, E3 and E4. In conclusion, the cryopreserved sperm from Holstein bulls revealed outstanding properties both after equilibration and after thawing with 0.125% lecithin nanoparticles, and they were sensitive to high dosages. [ABSTRACT FROM AUTHOR]

Melatonin is an intracellular antioxidant of sperm membrane that protects the cells from lipid peroxidation. Yet, its role as an antioxidant on semen quality of buffalo bulls is still obscure. The present study was undertaken to assess the effect of exogenous melatonin implant (18 mg/50 kg bodyweight) on post-thaw sperm characteristics, oxidative stress, endocrinological profiles and fertility of buffalo bulls. Six apparently healthy breeding Murrah buffalo bulls were randomly selected at bull farm, Guru Angad Dev Veterinary and Animal Sciences University for the present study and divided into two groups viz. control (n = 3) and melatonin implanted group (n = 3). A total of 120 ejaculates were collected from bulls of both groups (n = 60 each) throughout the study period. Most beneficial effects of melatonin implants were observed during post-implantation period. The percentages of post-thaw sperm total and progressive motility, viability and mitochondrial membrane potential were higher (p < .05) in melatonin implanted buffalo bulls compared to controls during post-implantation period. Following melatonin implantation, MDA production in post-thaw semen was lower (p < .05) in melatonin implanted group than in control group. Plasma melatonin and testosterone concentrations were higher (p < .05) in buffalo bulls implanted with melatonin as compared to their control counterparts. No differences (p > .05) in plasma LH concentrations were observed in both groups. First service pregnancy rate was 43.3% using semen of melatonin implanted bulls and 30.0% with semen of controls (p > .05). Thus, melatonin was able to protect sperm membrane against oxidative damage and improve post-thaw semen quality, thereby resulting in higher fertilizing potential of spermatozoa. [ABSTRACT FROM AUTHOR]

This study was conducted to investigate the relationship between the concentration of some fatty acids in seminal plasma and semen characteristics of Holstein bulls with different sperm freezabilities. The semen straws that cryopreserved for two years were divided into three groups according to the sperm’s freezability: medium (MF,73.02%), good (GF,83.76%), and high (HF,91.20%). The sperm’s cell individual motility (SCIM) in fresh semen was superior (P≤0.05) in bulls with MF and GF as compared with HF bulls. Concomitantly, the HF bulls were significantly (P≤0.05) superior to those MF bulls in total fatty acid concentrations. Moreover, HF bulls recorded lesser (P≤0.05) DNA damage percentage as compared with those of GF bulls. The differences among the three groups in concentrations of some fatty acid and SCIM at 48 hours and two years post-cryopreservation lacked significance. In conclusion, greater SCIM in bull's fresh semen recorded the lowest freezability, which indicated more sensitivity to freezing conditions and may reflect fertilizing ability of these bulls. [ABSTRACT FROM AUTHOR]

This study investigated the effect of different sperm freezability on some semen characteristics and amino acid concentrations in the seminal plasma of Holstein bulls cryopreserved for two years. The semen straws (0.25 ml) that cryopreserved for two years were divided into three equal groups (7 bulls per group) according to the sperm’s freezability: medium (73.02%; F1), good (83.76%; F2), and high (91.20%; F3). The F1 bulls were superior (P≤ 0.05) in sperm’s cell individual motility (SCIM) for fresh semen as compared with F2 and F3 bulls. The F2 and F3 groups were superior (P≤ 0.01) to the F1 group in live sperm percentage at cryopreservation. The sperm’s DNA damage percentage was lesser (P≤ 0.05) in the F1 and F3 groups as compared with the F2 group. The differences among groups in normal sperm percentage, sperm’s plasma membrane and acrosome integrity percentage, malondialdehyde, and total antioxidant concentrations lacked significance. The essential and non-essential amino acid concentrations in seminal plasma did not differ among groups. In conclusion, sperm freezability influenced some semen attributes but did not affect amino acid concentrations in the seminal plasma of Holstein bulls. [ABSTRACT FROM AUTHOR]

This study explored the effect of melatonin implantation on the fresh and cryopreserved semen quality of Iraqi buffalo bulls (Bubalus bubalis). Nine adult bulls were used and divided equally into three groups. The first group was left without treatment and regarded as control (T1), whereas the second (T2) and third (T3) groups were subcutaneously implanted with 72 and 90 mg of melatonin respectively on the left ear base and repeated one month post the first implantation. Semen was collected for 12 weeks and evaluated weekly for fresh, cooling, and post-cryopreserved (PC) protocols. The T3 group exhibited a higher (P≤0.05) sperm cell individual motility percentage, whereas, the T1 and T2 groups recorded better (P≤0.05) sperm acrosome integrity percentage for fresh semen. A lesser (P≤0.05) total sperm abnormality (TSA) percentage in the T2 and T3 groups and a greater (P≤0.05) sperm acrosome integrity (SAI) percentage in the T3 group were noticed during the cooling preservation. Moreover, the T3 group exhibited a lesser (P≤0.05) TSA percentage whereas, the T2 and T3 groups revealed a leaser (P≤0.05) SAI percentage during the PC period. Concomitantly, lower (P≤0.05) PC malondialdehyde concentration in seminal plasma was observed in the T2 and T3 groups than control group. In conclusion, the melatonin implantation (72 and 90 mg) ameliorated some fresh and PC semen attributes of the Iraqi buffalo bulls. [ABSTRACT FROM AUTHOR]

The elite bull plays an extremely important role in the genetic progression of the dairy cow population. The previous results indicated the potential positive relationship of large scrotal circumference (SC) with improved semen volume, concentration, and motility. In order to improve bull's semen quantity and quality by selection, it is necessary to estimate the genetic parameters of semen traits and their correlations with other conformation traits such as SC that could be used for an indirect selection. In this study, the genetic parameters of seven semen traits (n = 66,260) and nine conformation traits (n = 3,642) of Holstein bulls (n = 453) were estimated by using the bivariate repeatability animal model with the average information-restricted maximum likelihood (AI-REML) approach. The results showed that the estimated heritabilities of semen traits ranged from 0.06 (total number of motile sperm, TNMS) to 0.37 (percentage of abnormal sperm, PAS) and conformation traits ranged from 0.23 (pin width, PW) to 0.69 (hip height, HH). The highest genetic correlations were found between semen volume per ejaculation (SVPE), semen concentration per ejaculation (SCPE), total number of sperm (TNS), and TNMS traits that were 0.97, 0.98, 1.00, and 0.99, respectively. Phenotypic correlations between SC and SVPE, SCPE, TNS, and TNMS were 0.35, 0.35, 0.48, and 0.42, respectively. In summary, the moderate or high heritability of semen traits indicates that genetic improvement of semen quality by selection is feasible, where SC could be a useful trait for indirect selection or as correlated information to improve semen quantity and production in the practical bull breeding programs. [ABSTRACT FROM AUTHOR]

This study was investigated the relationship between Holstein bulls' fertility with some biomarkers (amino، fatty، and organic acids) and semen characteristics. The study included exploring the relationship among the fertility of Holstein bulls، several biomarkers، and semen characteristics in straws (20-25 straws/bull) preserved for three years. The cows were artificially inseminated (9-10 cows/bull) from semen. Based on the fertility rate، the bulls were divided into three groups، the first bulls of medium fertility (˂65%)، the second of good fertility (65-79%)، and the third of high fertility (>80%). The semen characteristics were evaluated، and the concentration of some amino acids and organic fatty acids was measured in the seminal plasma of bulls using gas chromatography and HPLC. The results revealed significant differences in the fertility rate among the different groups of bulls in favor of the highly fertile bulls. The results did not show any differences in most of the characteristics of the semen، except for a significant increase in the percentage of live sperm in good bulls compared to highly fertile ones. There were no significant differences for all the concentrations of carboxylic and most amino and fatty acids concentrations، except for an increase in the concentration of glycine acid (P˂0.05) and a decrease in the concentration of omega 9 (P˂0.05) in the highly fertile bulls compared to the medium fertile ones. In conclusion، glycine and omega-9 in the seminal plasma of bulls can be regarded as biomarkers of their fertility and the level of carboxylic acids (volatile fatty acids) can be adopted as an indicator of semen quality or energy level in the diet. [ABSTRACT FROM AUTHOR]

The objective of the current study was to investigate the influence of adding resveratrol (Res) to a milk-based extender on some post-thawed semen quality of Iraqi buffalo bulls for different preservation periods (cooling at 5˚C, 48 h, 1, and 2 months post-cryopreservation; PC). Four bulls, 3.5 to 4 years old, were used from 11th November 2020 to 1st June 2021. Semen samples were collected, pooled, and divided into four groups using different Res concentrations (0, 100, 150, and 200 μM) added to the milk extender. The Res-150 μM group exhibited higher (P≤0.01) plasma membrane, acrosome integrity percentages, and total antioxidants concentration (TAC) compared to the other groups. Sperm abnormalities and DNA damage percentages, as well as malondialdehyde (MDA) concentration, were lesser (P≤0.01) in the Res-150 μM group. Finally, Res-150 μM added to a milk-based extender increased the percentage of post-thawed live sperm and TAC in seminal plasma and minimized abnormal sperm percentage, DNA damage percentage, and MDA concentration in the seminal plasma of Iraqi buffalo bulls. [ABSTRACT FROM AUTHOR]

The present study comprehensively evaluates the postnatal growth, hematology, telomere length, and semen attributes of multiple clones and re-clone derived from superior buffalo breeding bulls. To the best of our knowledge, we successfully produced multiple clones and a re-clone of an earlier cloned buffalo bull from an embryo developed from an adult bull's skin-derived cell for the first time. The cloned bulls' growth, blood hematology, plasma biochemistry, and telomere length were all shown to be normal at various stages of development. The bulls were used for semen production after being screened for testicular growth and training. Semen characteristics such as volume, concentration, and initial motility of fresh sperm as well as motility and kinetics characteristics such as straightness (STR), average lateral head displacement (ALH), and beat cross frequency (BCF) of frozen-thawed sperms of the cloned bulls were found to be similar to those of non-cloned bulls, including the donor bulls. Additionally, it was found that cloned bulls' functional sperm attributes, including acrosome intactness, mitochondrial membrane potential, and superoxide anion status, were comparable to those of non-cloned bulls. These characteristics are necessary for sperm to pass through the female reproductive system, penetrate the oocyte, and efficiently fertilize. Finally, this study adds to our understanding of the postnatal development, hematology, telomere length, and sperm characteristics of superior buffalo breeding bulls that have been cloned and re-cloned. The findings provide the groundwork for improving cloning practices, refining reproductive procedures, and optimizing the use of cloned genetic material in animal breeding and conservation. • Using skin-derived cells, the study produced multiple clones and effectively re-cloned a buffalo bull, achieving major scientific breakthrough. • Clones of buffalo bulls demonstrated normal postnatal growth, indicating that the cloning procedure had no negative impact on their overall health and development. • The cloned bulls' telomere length, remained within normal ranges, indicating that their cells maintained genetic stability over time. • Multiple clones produce high-quality sperm, a key aspect of their reproductive potential. [ABSTRACT FROM AUTHOR]

Simple Summary: Bull fertility greatly impacts the profitability of the cattle production system. Therefore, in vivo semen analysis is an option to predict the potential fertility of the sire. The results showed an effect of the mating period on bull sperm morphometric and displayed spermatozoon with a more linear and faster progressiveness. In addition, we demonstrated an overall decrease in overtime on sperm morphometrical traits of the sperm head and midpiece. Therefore, the results obtained help us understand how the mating period affects a bull's sperm quality while opening the possibility for future research in other species. The objective of the present study was to determine the effects that the reproductive season has on the motility, kinematics, morphology, and sperm morphometry of Brahman bulls evaluated with a commercial CASA system. The experiment was carried out at the Costa Rica Institute of Technology from March to August 2021. A total of eight Brahman bulls were used. A total of 28 ejaculates were collected in the pre-mating period (PMP), during it (DMP), and after it (AMP) using an electroejaculator. The sperm concentration was measured with the Accuread photometer. The motility was measured using a Spermtrack® counting chamber. The analyses were performed with the CASA-Mot ISAS®v1 system. The morphology was analyzed using a microscope with a negative phase contrast objective. Morphometry was evaluated with the CASA-Morph. The sperm concentration did not present differences between the PMP and AMP; however, it was significantly higher than DMP (p > 0.05). Regarding the progressiveness variables, linearity on forward progression (LIN), straightness (STR), and wobble (WOB) were higher (p < 0.05) DMP. A kinematic principal component analysis grouped all the variables into three factors and an effect on the reproductive period was found (p < 0.05) in the parameters of the head and middle part of the sperm, such as width and perimeter, which were greater in the PMP. The length of the sperm head in the PMP and DMP did not show differences; however, both were larger (p < 0.05) than AMP. The insertion distance of the middle piece of the sperm was significantly greater than DMP. Finally, the PMP contained cells with a larger insertion angle (p < 0.05) than AMP. These findings are important to understand the implications of reproductive status on sperm quality and to consider them in andrological evaluations. [ABSTRACT FROM AUTHOR]

This study was undertaken to figure out the relationship between some biochemical characteristics in seminal plasma with the semen quality of Iraqi buffalo bulls (Bubalus bubalis). Semen was diluted with the Tris extender and divided based on the sperm cell's individual motility into two groups. The first group included good-semen quality (GS; n=3), whereas, the second group included poor-semen quality (PS; n=5). The differences between GS and BS groups in all seminal biochemical attributes lacked significance. A negative and significant (P≤0.05) correlation coefficient was noticed between cholesterol concentration and both principal and terminal sperms abnormality (r= -0.52), and total abnormalities (r= -0.53). A positive and significant (P≤0.05) correlation coefficient was shown between cholesterol concentration and normal sperm percentage (r= 0.53). Moreover, there was a negative and significant correlation (P≤0.05) between the triglyceride concentration and each of the percentages of individual sperm motility (r = -0.50) and of live sperm (r = -0.51). It can be concluded that some biochemical characteristics of seminal plasma can be used to predict the semen quality and fertility of Iraqi buffalo bulls. [ABSTRACT FROM AUTHOR]

Background: Cryopreservation is an invaluable technique yet it is also known to be detrimental to sperm function and fertility due to cryo-injury and concomitant generation of reactive oxidants. During laboratory manipulation for the cryopreservation and freeze-thaw process, spermatozoa undergo osmotic stress, ionic imbalance, metabolic decoupling, membrane phase transition, destabilization of the cytoskeleton and antioxidant depletion which communally hampers the semen quality. Methods: With the aim of determining implications of cryopreservation and storage, semen samples were collected by artificial vagina technique from 12 Murrah bulls and subsequently examined at 0 hour (before cryopreservation) and at 24 hour, 1 month and 2 month of storage for various seminal attributes. Simultaneously seminal plasma was separated and preserved at -20oC till the analysis of biochemical indicators of semen quality viz., nitric oxide (NO), total antioxidant quantity (TAC) and lipid peroxidation status (TBARS). Result: A sharp reduction (p<0.01) in the semen quality was observed only at 24 h after cryopreservation except for viability. Significant reduction (p<0.05) in viable counts was observed up to 1 month interval. The capacitated sperm percentage was greater (p<0.01) in the cryopreserved semen as compared to fresh ejaculate. The mean±SE levels of NO (μmol/L), TAC and TBARS (Units/ml) was 2.31±0.27, 0.73±0.04 and 1.11±0.16 respectively in seminal plasma of neat semen stored at -20oC, while the values in the extended seminal plasma after cryopreservation was 2.37±0.31, 0.44±0.03 and 0.65±0.03 respectively. So it can be inferred that most of the damage encountered by spermatozoa is during the initial period of freezing, but the damage associated by various stressors cannot be ignored. [ABSTRACT FROM AUTHOR]

The success of assisted reproduction relies on functional competence of frozen-thawed semen. Heat stress affects protein folding leading to aggregation of mis-folded proteins. Hence, a total of 384 (32 ejaculates/bull/season) ejaculates from six matured Gir bulls were used to evaluate physico-morphological parameters, the expression of HSPs (70 and 90) and fertility of frozen-thawed semen. The mean percent individual motility, viability and membrane integrity were significantly (p < 0.01) higher in winter compared to summer. Out of 1200 Gir cows inseminated, 626 confirmed pregnant and the mean conception rate of winter (55.04 ± 0.35) was significantly (p < 0.001) higher than summer (49.33 ± 0.32). A significant (p < 0.01) difference in concentration of HSP70 (ng/mg of protein) but not HSP90was observed between the two seasons. The HSP70 expression in pre-freeze semen of Gir bulls had significant positive correlation with motility (p < 0.01, r = 0.463), viability (p < 0.01, r = 0.565), acrosome integrity (p < 0.05, r = 0.330) and conception rate (p < 0.01, r = 0.431). In conclusion, the season influences physico-morphological parameters and expression of HSP70 but not HSP90 in Gir bull semen. The HSP70 expression is positively correlated with motility, viability, acrosome integrity and fertility of semen. The semen expression of HSP70 may be utilized as biomarker for thermo-tolerance, semen quality and fertilizing capacity of Gir bull semen. [ABSTRACT FROM AUTHOR]

Simple Summary: A study was conducted to investigate five semen traits in Egyptian buffalo bulls using a single-step genome-wide association study for genomic evaluation. The study aimed to identify associated genomic regions and potential candidate genes. The X-chromosome was the most crucial, accounting for 23.43% of the overall genomic variance observed in these semen traits. Numerous potential candidate genes associated with the examined semen traits were identified within the genomic regions under investigation. In addition, a total of five new candidate genes were discovered within the genomic area examined for semen traits in Egyptian buffalo bulls. The present study aimed to contribute to the limited research on buffalo (Bubalus bubalis) semen traits by incorporating genomic data. A total of 8465 ejaculates were collected. The genotyping procedure was conducted using the Axiom® Buffalo Genotyping 90 K array designed by the Affymetrix Expert Design Program. After conducting a quality assessment, we utilized 67,282 SNPs genotyped in 192 animals. We identified several genomic loci explaining high genetic variance by employing single-step genomic evaluation. The aforementioned regions were located on buffalo chromosomes no. 3, 4, 6, 7, 14, 16, 20, 22, and the X-chromosome. The X-chromosome exhibited substantial influence, accounting for 4.18, 4.59, 5.16, 5.19, and 4.31% of the genomic variance for ejaculate volume, mass motility, livability, abnormality, and concentration, respectively. In the examined genomic regions, we identified five novel candidate genes linked to male fertility and spermatogenesis, four in the X-chromosome and one in chromosome no. 16. Additional extensive research with larger sample sizes and datasets is imperative to validate these findings and evaluate their applicability for genomic selection. [ABSTRACT FROM AUTHOR]

The study compared efficacy of three sperm selection techniques in improving freezability of low-quality Murrah buffalo bull ejaculates. Sephadex (SEP), Sephadex ion-exchange filtration (SIE), and 40/80% BoviPure™(BP) gradient centrifugation protocols were standardized (ejaculates, n = 24). In Experiment-I, Sephadex G-75, G-100, and combined Sephadex G (75–100) column filtrates were compared. In Experiment-II, BP protocols: 200 g-10 min, 250 g-5, and 10 min, 300 g-10, and 15 min were compared. In fresh semen, Sephadex G (75–100) filtration and 250 g-5 min BP protocol improved sperm functions and were used in Experiment-III, where SEP G (75–100), SIE G (75–100), and 250 g-5 min BP processed ejaculates (n = 48) were cryopreserved and compared at post-thaw stage. The mean recovery rate differed in order: SEP > SIE > BP. SIE filtration significantly improved progressive motility, livability, membrane integrity, bovine cervical mucus penetration and live non-apoptotic sperm. Compared with control, all three techniques equally reduced post-dilution and post-thaw lipid peroxidation (LPO) rate. SEP post-thaw filtrates observed lower cryocapacitation-like changes, LPO (C11‐BODIPY581/591), and higher active mitochondria than other treatments. SIE and SEP equally improved post-thaw acrosome-intact sperm over BP. Filtration techniques, preferably, Sephadex ion-exchange filtration can most efficiently process low-quality buffalo bull ejaculates for cryopreservation and improve freezability. [ABSTRACT FROM AUTHOR]

The aim of this study was to estimate genetic parameters and investigate the genomic background of scrotal circumference and semen parameters in the Italian Simmental bulls. Scrotal circumference, number of normal spermatozoa, ejaculate volume, spermatozoa motility, and total spermatozoa were measured on 622 bulls, of which 603 had genotypes for 42,141 SNP. Variance components of scrotal circumference were estimated with an animal model that included the fixed effects of birth year, animal age, and measurement method, and the random effects of day of measurement and animal. In the model for the other traits, the scrotal circumference was added as a covariate to account for its influence on the semen parameters. A genome-wide association study was carried out using the ssGBLUP-approach. Heritabilities ranged from 0.07 ± 0.05 (spermatozoa motility) to 0.50 ± 0.14 (scrotal circumference). A total of 13 SNP passed the Bonferroni correction threshold and the number of significantly associated markers ranged from 1 (ejaculate volume and spermatozoa motility) to 5 (total spermatozoa). Genes already associated with reproduction parameters were retrieved close to the significant SNP. Results of the present study gave preliminary insights about the genetic determinism of semen quality in Italian Simmental bulls. Low to moderate heritabilities were estimated for semen traits. Few markers were associated with the phenotypes, suggesting their polygenic determinism. Candidate genes already associated in literature with sperm traits were found. [ABSTRACT FROM AUTHOR]

Background: Bio-acoustic features of animal’s voice can provide meaningful information about their biological and physical characteristics. The present study was conducted to get indicators of age from voice analysis and explore the relationship between voice features and seminal parameters in Sahiwal bulls. Methods: Voice samples were collected from healthy bulls (n=20), maintained at ICAR-NDRI, Karnal. Bulls were classified into two groups i.e. young bulls and adult bulls. The voice signals were analyzed by Adobe Premium software and acoustic features were extracted by using PRAAT software. Result: The mean of acoustic features viz. call duration (sec), mean intensity (dB), total energy (P2S), amplitude (P), pitch (Hz), unvoiced frame (%), jitter (%), bandwidth (Hz) mean N/H ratio (%) have been found significantly different while mean H/N ratio (dB), shimmer (%) and pulses were not found statistically (P>0.05) different between adult and young bulls. The seminal parameters viz mass activity (0-5 scale), individual progressive motility (%), live sperm count (%) and total sperm abnormality (%) were found significantly different between adult and young bulls. No significant association between voice features and semen quality of bulls was observed. Hence, voice signals of male might provide some clues about their age but for semen quality, there is further need to explore the interesting relationship between voice features and fertility of breeding bulls. [ABSTRACT FROM AUTHOR]

In this study, the relationships between post‐thaw bull sperm characteristics and hyperketonemic conditions after coincubation with cow plasma or media were determined to investigate if such a condition could affect bull sperm characteristics. Two experiments were conducted. In experiment 1, blood samples were collected from 31 cows to prepare plasma. Cows were independently categorized into two groups according to plasma β‐hydroxybutyrate (BHB) concentrations (above or below 1.2 mM). Thawed bull semen was diluted and incubated with diluted plasma; motility parameters were evaluated using Computer Assisted Semen Analysis (CASA). In experiment 2, a pooled sample of thawed semen was diluted and divided into three aliquots: without BHB (control) and treated with either 1.2 mM (1.2) or 3 mM (3) BHB. In addition to motility, flow cytometric analyses were carried out. In experiment 1, the overall motility decreased significantly in plasma containing high (≥1.2 mM) BHB compared to plasma containing low (<1.2 mM) BHB. In experiment 2, the overall motility tended to be lower in BHB (3 mM)‐supplemented samples. The supplementation of 3 mM BHB increased the proportion of live superoxide‐positive sperm and sperm with high mitochondrial potential, while the DNA fragmentation index decreased. [ABSTRACT FROM AUTHOR]

Flow cytometry (FC) is a very powerful method for the assessment of spermatozoa quality in multiple livestock species, including bulls. Nowadays, many flow cytometric tests are available for quality detection of bull sperm. These tests are based on fluorochromes (fluorescent tags or dyes) and the use of correct concentrations of fluorochromes is an essential aspect of the successful optimization of experimental methodology. Modern flow cytometers are much more affordable, such that spermatologists are now able to use FC methodology (and even image cytometry) in their studies. The present review aims to give a summary of current flow cytometric methodologies used to assess bull sperm quality by flow cytometry. Namely, we give here the concentrations of fluorochromes used in the studies related to bull sperm quality evaluation by flow cytometry published in the last three years (from 2021 to 2023). Importantly, in the present review, the concentration of fluorochromes is unified and presented using comparable molarity units. Furthermore, the rationale of each flow cytometric methodology for particular fluorescent tests, and the citation for the corresponding original methodology, are given. This review will help spermatologists shorten the time needed for the optimization of their flow cytometry methodology for the assessment of bull sperm quality. [ABSTRACT FROM AUTHOR]

The present study was aimed to determine the effect of ATP dose rate on seminal attributes of frozen-thawed buffalo bull's semen. For this purpose, 20 frozen semen straws of four different buffalo bulls were obtained from a private semen production unit (Al-Hiawan Sires, Sahiwal). The experiment was replicated four times. In each replicate, four frozen straws of the same bulls were thawed and pooled. After evaluating the motility, the pooled frozen-thawed sample was aliquoted into three separate tubes containing 0 (control), 1-, or 2-mM concentrations of ATP. Afterward, each aliquot was incubated at 37oC for 4 hrs. The sperm motility, viability, and membrane integrity were observed at various time points (10 min., 1hr, 2hr, and 4hr) during the incubation period of four hrs. It was observed that progressive motility and most of the motion kinematic parameters were greater (P<0.05) in control. A significant (P<0.05) interaction was observed between ATP dose and incubation time. The progressive motility, total motility, VCL, VAP, ALH, and BCF decreased (P<0.05) both by incorporation of ATP (1mM or 2mM) and increasing incubation time (from 10 min to 4hrs) which indicate the ATP and incubation time of 4 hours negatively affect the motion kinetics of buffalo bull semen. In conclusion, it was witnessed that the motility and plasma membrane integrity of sperm declined by the supplementation of ATP in frozen-thawed buffalo bull semen. [ABSTRACT FROM AUTHOR]

Enzootic bovine leukosis virus (BLV) and bovine herpesvirus 1 (BHV-1) are very important infectious agents for the livestock industry worldwide. The present study aimed to explore the association between natural exposure to BLV and BHV-1 with sperm quality analyzed by Computer-Assisted Semen Analysis (CASA) systems. Ten sexually mature Brahman bulls, with sanitary status BLV+/BHV-1+ (n = 2), BLV−/BHV-1+ (n = 6) and BLV-/BHV-1- (n = 2) were evaluated twice, 30 days apart. Results showed that sanitary status of each bull was not associated with semen quality. It was found that the quality of the semen from the second collection was better due to the interruption of sexual rest. The evidence thus revealed that a bull infected with BLV generated good-quality contaminated semen and, therefore, that it is essential to detect contaminated seminal samples to prevent the spread of BLV. A multivariate analysis showed the presence of four sperm subpopulations in Brahman bulls that differ significantly in their kinematic patterns and with respect to sanitary status (P < 0.05), indicating that infection-free and seronegative bulls present the best kinematic parameters, which improved discrimination of sperm quality according to sanitary status. Overall, the analyses indicate that the seropositive-infected bulls with BLV and BHV-1 should be excluded from beef cattle farms. [ABSTRACT FROM AUTHOR]

This study aimed to reveal the effects of juniper (Juniperus communis) berry oil (JB) when added to the Tris extender, on bull (Holstein) sperm motility characteristics, abnormal sperm ratio, DNA fragmentation and some oxidative stress markers. The pooled ejaculate was divided into five equal parts as control (C) and Tris diluent containing 25, 50, 100, 200 μg/ml JB. Diluted semen was incubated at 4 °C for 4 h and then frozen in liquid nitrogen (--196 °C). After freezing-thawing, motility characteristics were determined using a sperm analyzer system. The results showed that the 25 μg/ml dose of JB had an improving effect on overall sperm motility (P < 0.05). The total abnormal spermatozoa ratio was not significantly different between the groups (P > 0.05). The JB25 and JB50 groups had higher DNA integrity than the other groups (P < 0.05). This finding was supported by low malondialdehyde levels (P < 0.05). Especially the 25 μg/ml dose of JB was found to have a remedial effect on DNA integrity, as well as increasing progressive and total motility rates. This study has revealed new information on the effects of JB on bull semen cryopreservation. Juniper berry oil may be used as an antioxidant in bull semen freezing. [ABSTRACT FROM AUTHOR]

Semen of all bulls is not suitable for freezing; similarly, all ejaculates with excellent sperm vitality are not suitable for freezing. Based on sperm survival at post-thawing, bull ejaculates are categorized as good freezability ejaculates (GFE) and poor freezability ejaculates (PFE). In this study, sperm quality parameters of GFE and PFE, with the localization of aquaporin-3 (AQP-3) and aquaporin-7 (AQP-7) were investigated. Moreover, the relationship of AQP-3 and AQP-7 with cryotolerance of bull sperms was recorded. After fresh semen evaluation, 24 ejaculates from four Angus bulls were cryopreserved and their sperm quality parameters were analyzed by AndroVision before and after frozen-thawed. Expression of AQP-3 and AQP-7 was determined through Western blot, while their localization was detected by immunocytochemistry. The GFE and the PFE were well differentiated by sperm motility, progressive motility, viability, acrosome integrity, and mitochondrial activity, except for DNA integrity. AQP-3 was significantly higher in GFE than PFE in frozen-thawed sperm, while the AQP-7 in fresh sperm of GFE was significantly higher than that in fresh sperm of PFE and in frozen-thawed sperm of GFE (P<0.05). The location of AQP-3 was seen in the sperm mid-piece, while that of AQP-7 was recorded in the post-acrosome region, the mid and prime tailpiece. In conclusion, GFE and PGE can be well distinguished by the expression of AQP-7 in fresh semen, while AQP-7 could be a biomarker of sperm cryotolerance in bull sperm. This study is hoped to improve the efficiency of frozen sperm production and provide a reference for the improvement of frozen semen production technology in other male animals, as well as humans. [ABSTRACT FROM AUTHOR]

This study was attempted to estimate the genetic parameters of semen quality traits in buffalo bulls. The study data consisted of 10975 ejaculates from 45 Murrah buffalo bulls (aged 24–72 months) used for breeding program during year 2010 to 2020. Semen quality traits (ejaculate volume, concentration of sperm, mass activity, initial and post-thaw motility, number of sperms per ejaculate, motile sperm number and discard rates) were studied. It was observed that average ejaculate volume was 2.82 ± 1.45 mL with mean concentration of 1040.12 ± 523.26 million/mL. Higher heritability was observed for number of sperms per ejaculate, number of motile sperm and sperm concentration. Significant phenotypic correlation was obtained between volume and number of sperms per ejaculate as well as volume and number of motile sperms. Likewise, significant phenotypic correlation was evident between sperm concentration with sperm number per ejaculate. Highest phenotypic correlation was obtained between sperm count per ejaculate and motile sperm count. Estimated genetic trends showed significant change in volume and motile sperm number. In conclusion, this study ascertains that genetic parameters of semen traits can be considered during the selection of buffalo bulls in breeding program. [ABSTRACT FROM AUTHOR]