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

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

Evaluation of predictive ability of linear type gonadal traits on reproductive capacity of breeding dairy bulls.

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.

Transscrotal stimulation of the testes and epididymides improves urethral sperm collection in domestic cats.

Urethral catheterisation after medetomidine administration is the method of choice for semen collection in cats, but it yields variable results. This study tested whether scrotal manual stimulation can improve urethral sperm collection in domestic cats. The study was performed on 20 male cats, from which two urethral semen samples were collected, one before and one after 2min of transscrotal finger massage of the testes and epididymides. Both sperm samples were assessed for total sperm count and motility using computer-aided sperm analysis, viability and morphology (eosin-nigrosin staining). The transscrotal manual stimulation allowed a significantly higher number of spermatozoa to be obtained (P=0.0015). Viability was similar before and after the stimulation (median 92% and 90.5%), whereas the number of motile (median 60% and 70%) and morphologically normal (median 17% and 30.5%) spermatozoa was higher in the second sample (P=0.03 and P=0.002 respectively), which confirms that transscrotal massage induced the expulsion of a fresh pool of spermatozoa into the urethra. Transscrotal stimulation of the testes and epididymides significantly improves urethral semen collection in domestic cats and can be easily introduced into clinical practice.

Scrotal subcutaneous temperature is increased by scrotal insulation or whole-body heating, but not by scrotal neck insulation; however, all three heat-stress models decrease sperm quality in bulls and rams.

Ruminant testes are ~2-6 °C below body temperature; increased testicular temperature reduces sperm motility and morphology. Our objective was to serially monitor scrotal subcutaneous temperatures during testicular heat stress and relate those to sperm quality. Two experiments were conducted, with temperature sensors surgically implanted in scrotal subcutaneous tissues recording temperatures every 15 min and semen collected and evaluated weekly. After an initial control interval, testicular temperature was increased. In Experiment 1, in two Angus bulls, whole-scrotum insulation for 96 h increased scrotal subcutaneous temperatures by ~2.0-2.5 °C (P < 0.05). Total and progressive motility decreased (P < 0.05) and reached a nadir at Week 3 (~20 and 10%, respectively). Furthermore, morphologically normal sperm and acrosome integrity also decreased significantly, reaching nadirs at Weeks 3 (15%) and 4 (34%). In Experiment 2, 10 Dorset rams were allocated randomly into two equal groups and either: 1) exposed to 28 °C ambient temperature and 30-34% RH for 8 h/d for 4 d; or 2) subjected to scrotal neck insulation that was applied and removed at the same time as the start and completion, respectively, of heat exposures in the other rams. Scrotal subcutaneous temperatures (monitored in three rams per group) were increased in response to whole-body heating (~0.8 °C, P < 0.05), but not significantly changed by scrotal neck insulation. Decreases in sperm quality were generally similar between treatments, with the most profound changes evident 4 wk after heat stress, with ~10 percentage point reductions in both total and progressive motility and ~10 and 20 percentage point decreases in morphologically normal sperm in rams with whole-body heating versus scrotal neck insulation, respectively. In conclusion, scrotal subcutaneous temperature was significantly increased by scrotal insulation or whole-body heating, but not by scrotal neck insulation; however, all three heat-stress models decreased sperm motility and morphology in bulls and rams.

Scrotal thermoregulation and sequential sperm abnormalities in buffalo bulls (Bubalus bubalis) under short-term heat stress.

Heat stress reduces the reproductive capacity of bulls raised in tropical climate. However, the reestablishment of scrotal thermoregulation and the dynamics of sperm defects emergence after stress are not completely known in buffaloes. Thus, the study aimed to evaluate the effect of short-term heat stress over scrotal thermoregulation and sperm attributes, relating them to spermatogenesis stages. Five buffalo bulls went through scrotal insulation during 48 h (from day 0 to day 2). Semen samples were collected every 7 days (from day -7 to day 49) and analyzed about the progressive motility, viability, and sperm morphology. Heat stress significantly destabilized scrotal thermoregulation (P < 0.001). Scrotal temperature was from 4.2 to 6.3 °C lower than the core body temperature, except on insulation days (P < 0.001), and returned to the basal condition five days after the removal of the stressing stimulus. More significant deleterious effects were observed in sperm morphology than in cell concentration, motility, and viability. The chronology of morphologic defects expression demonstrated tail defects (days 7-14), cytoplasmic droplets (days 14-28), and head defects (day 28), returning to pre-insulation condition 35 days after the thermal challenge. Thus, hyperthermia harmed more intensely spermatozoa in epididymal transit, elongated spermatids, and secondary spermatocytes. It is concluded that water buffalo bulls present a peculiar manifestation of sperm morphology after short-term stress, indicating an important difference related to the bovine species. Therefore, during the andrological evaluation of buffalo bulls, it is necessary to avoid the allometric extrapolation between these species.

Antisperm antibodies and sperm function in bulls undergoing scrotal insulation.

Bovine antisperm antibodies (ASAs) have been associated with teratospermia and asthenospermia. It was hypothesized here that scrotal insulation induces the formation of ASAs and deterioration of sperm function. Scrotal insulation bags were placed in 10 bulls for 8 days. Semen was collected on days -29, -22 and -2, twice weekly from days 5 to 54, and thereafter weekly until day 96 (day 0 = first day of scrotal insulation). On each collection day, scrotal circumference, sperm motility, morphology, membrane integrity, acrosome integrity, apoptosis, lipid peroxidation, mitochondrial membrane potential, ASA binding and DNA integrity were evaluated. The percentage of IgG- and IgA-bound sperm increased between days 12 and 96 (P < 0.0001), in association with poor motility (days 19-30, P < 0.005) and morphology (days 8-40, P < 0.0001). Mean scrotal circumference decreased between days 15 and 75 (P < 0.0001). There was also a deterioration in sperm membrane integrity (days 19-40, P < 0.0001), acrosome integrity (days 26-89, P < 0.0001), lipid peroxidation (days 5-12, P < 0.0001), and mitochondrial membrane potential (days 12-96, P = 0.001). In contrast, a decrease in apoptotic cells (days 37-83, P = 0.0002) and lipid peroxidation (days 19-96, P < 0.0001) was noticed. Most bulls recovered normospermia by day 96. However, the persistence of ASAs, acrosomal damage and dysfunctional mitochondria suggest a long term effect of scrotal insulation on sperm function and the homeostasis of the reproductive immune system.

Effects of increased scrotal temperature on semen quality and seminal plasma proteins in Brahman bulls.

Environmental temperature has effects on sperm quality with differences in susceptibility between cattle subspecies and breeds, but very little is known about the seminal plasma protein (SPP) changes resulting from testicular heat stress. Scrotal insulation (SI) for 48 hr was applied to Brahman (Bos indicus) bulls. Semen was collected at 3-day intervals from before, until 74 days post-SI. The changes in sperm morphology and motility following SI were comparable to previously reported and differences were detected in measures of sperm chromatin conformation as early as 8 days post-SI. New proteins spots, in the SPP two-dimensional (2-D) gels, were apparent when comparing pre-SI with 74 days post-SI, and SPP identified as associated with mechanisms of cellular repair and protection. Similar trends between 2-D gel and Sequential Window Acquisition of All Theoretical Mass Spectra (SWATH-MS) data was observed, with SWATH-MS able to quantify individual SPP that otherwise were not resolved on 2-D gel. The SPP assessment at peak sperm damage (21-24 days) showed a significant difference in 29 SPP (adjusted p < .05), and identified six proteins with change in abundance in the SI group. In conclusion both spermatozoa and SPP composition of bulls are susceptible to temperature change incurred by SI, and SPP markers for testicular heat insults may be detected.

Effect of transient scrotal hyperthermia on human sperm: an iTRAQ-based proteomic analysis.

BACKGROUND: Through this prospective study, we aimed to explore the change of molecular modification after the transient scrotal hyperthermia on human sperm. METHODS: Ten healthy subjects selected with strict screening criteria underwent testicular warming in a 43 °C water bath for 30 min a day for 10 consecutive days. Semen samples were collected 2 weeks before the first heat treatment and 6 weeks after the first heat treatment. Proteins from the samples were labeled with isobaric tags for relative and absolute quantitation and analyzed by two-dimensional liquid chromatography-tandem mass spectrometry. RESULTS: In contrast to the control, of the 3446 proteins identified, 61 proteins were deregulated: 28 were up-regulated and 33 were down-regulated. Approximately 95% of the differentially expressed proteins were found to participate in spermatogenesis, fertilization, or other aspects of reproduction. In particular, the expression of sperm motility and energy metabolism-related proteins AKAP4, SPESP1, ODF1, ODF2, GAPDHS, and ACTRT2, validated by western blotting of the proteins obtained from human and mouse samples, tended to be reduced under scrotal hyperthermia. CONCLUSIONS: The results indicated that the proteins AKAP4, ODF1, ODF2, GAPDHS, SPESP1, and ACTRT2, play an important role in the heat-induced reversible reduction in sperm concentration and motility and have the potential to be the biomarkers and clinical targets for scrotal heat treatment induced male infertility.

Frequent and mild scrotal heat stress impairs embryo development, implantation and offspring sex ratio in mice.

RESEARCH QUESTION: Frequent and mild scrotal heat stress (fmSHS) often occurs in humans. The aim of this study was to determine the impact of fmSHS on natural fertility, the IVF-embryo transfer (IVF-ET) process and the offspring sex ratio. DESIGN: Male mice were randomly divided into four groups: no scrotal heat stress (SHS) (controls) and those subjected to SHS at 37°C, 39°C or 41°C for 30 min once a week for 5 consecutive weeks. The testis, epididymis and sperm quality were assessed to evaluate the effects of different degrees of SHS, to establish an fmSHS model. Then, natural fertility, IVF-embryo transfer (IVF-ET) results, embryo development, offspring sex ratio and the X/Y chromosome-bearing sperm ratio were examined. RESULTS: SHS at 39°C and 41°C caused mild impairment to spermatozoa, leading to a phenotype similar to oligoasthenozoospermia in humans. Given that most SHS conditions in humans are close to body temperature, SHS of 39°C was adopted to build the fmSHS model. fmSHS reduced the fertilization rate, impaired on-time development and reduced the implantation rate of the embryos in the IVF-ET process, but it did not affect the development or function of blastocysts. The fmSHS mice produced more Y chromosome-bearing spermatozoa and propagated more male offspring. CONCLUSIONS: fmSHS not only reduced the fertilization ability of spermatozoa but also influenced their function beyond fertilization, in addition to changing the offspring sex ratio. These results may help to shed new light on the infertility treatment of males with scrotal heat risk and the health concerns of offspring propagated from these fathers.

Male Urogenital System Mapped Onto the Sensory Cortex: Functional Magnetic Resonance Imaging Evidence.

INTRODUCTION: The projection of the human male urogenital system onto the paracentral lobule has not previously been mapped comprehensively. AIM: To map specific urogenital structures onto the primary somatosensory cortex toward a better understanding of sexual response in men. METHODS: Using functional magnetic resonance imaging, we mapped primary somatosensory cortical responses to self-stimulation of the penis shaft, glans, testicles, scrotum, rectum, urethra, prostate, perineum, and nipple. We further compared neural response with erotic and prosaic touch of the penile shaft. MAIN OUTCOME MEASURE: We identified the primary mapping site of urogenital structures on the paracentral lobule and identified networks involved in perceiving touch as erotic. RESULTS: We mapped sites on the primary somatosensory cortex to which components of the urogenital structures project in men. Evidence is provided that penile cutaneous projection is different from deep penile projection. Similar to a prior report in women, we show that the nipple projects to the same somatosensory cortical region as the genitals. Evidence of differential representation of erotic and nonerotic genital self-stimulation is also provided, the former activating sensory networks other than the primary sensory cortex, indicating a role of "top-down" activity in erotic response. CLINICAL IMPLICATIONS: We map primary sites of projection of urogenital structures to the primary somatosensory cortex and differentiate cortical sites of erotic from nonerotic genital self-stimulation. STRENGTH & LIMITATIONS: To our knowledge, this is the first comprehensive mapping onto the primary somatosensory cortex of the projection of the components of the urogenital system in men and the difference in cortical activation in response to erotic vs nonerotic self-stimulation. The nipple was found to project to the same cortical region as the genitals. Evidence is provided that superficial and deep penile stimulation project differentially to the cortex, suggesting that sensory innervation of the penis is provided by more than the (pudendal) dorsal nerve. CONCLUSION: This study reconciles prior apparently conflicting findings and offers a comprehensive mapping of male genital components to the paracentral lobule. We provide evidence of differential projection of light touch vs pressure applied to the penile shaft, suggesting differential innervation of its superficial, vs deep structure. Similar to the response in women, we found nipple projection to genital areas of the paracentral lobule. We also provide evidence of differential representation of erotic and nonerotic genital self-stimulation, the former activating sensory networks other than the primary sensory cortex, indicating a role of top-down activity in erotic response. Allen K, Wise N, Frangos E, et al. Male Urogenital System Mapped Onto the Sensory Cortex: Functional Magnetic Resonance Imaging Evidence. J Sex Med 2020;17:603-613.

Impact of Metabolically Healthy Obesity in Patients with Andrological Problems.

BACKGROUND: Although the pathogenic role of metabolically complicated obesity (MCO) in erectile dysfunction (ED), major adverse cardiovascular events (MACE), and male infertility has been widely studied, that of metabolically healthy obesity (MHO) has been poorly investigated. AIM: To assess the role of MHO in the pathogenesis of ED, prediction of MACE, and male reproductive health. METHODS: A consecutive series of 4,945 men (mean age, 50.5 ± 13.5 years) with sexual dysfunction (SD) (cohort 1) and 231 male partners of infertile couples (mean age, 37.9 ± 9.1 years; cohort 2) were studied. A subset of men with SD (n = 1,687) was longitudinally investigated to evaluate MACE. All patients underwent clinical, biochemical, erectile function, and flaccid penile color Doppler ultrasound (PCDU) assessment. Infertile men also underwent scrotal and transrectal ultrasound; semen analysis, including interleukin (IL-) 8; and prostatitis-like symptom assessment. MHO was defined as body mass index >30 kg/m2 with high-density lipoprotein cholesterol level >40 mg/dL and absence of diabetes or hypertension. The rest of the obesity sample was defined as MCO. MHO or MCO were compared with the rest of the sample, defined as normal weight (NW) individuals. OUTCOMES: Clinical, biochemical, erectile, and PCDU assessment in MHO, MCO and NW men in both cohorts; longitudinal MACE incidence assessment in cohort 1. RESULTS: In cohort 1, 816 men (16.5%) were obese, 181 (3.7%) were MHO, and 635 (12.8%) were MCO. In cohort 2, 68 men (28.4%) were obese, 19 (8.2%) were MHO, and 49 (21.2%) were MCO. After adjusting for confounders, in both samples, the men with MHO and MCO had lower total testosterone levels and worse PCDU parameters compared with the NW men. However, only MCO men had worse erectile function compared with NW men. In the longitudinal study, both MHO and MCO men independently had a higher incidence of MACE compared with NW men (P < .05 for both). In cohort 2, MHO and MCO men had a larger prostate volume, and MCO men also had higher ultrasound and biochemical (IL-8) features of prostatic inflammation compared with NW men, but no differences in prostatitis-like symptoms or seminal parameters. CLINICAL IMPLICATIONS: MHO men should be considered at high cardiovascular risk like MCO men and followed-up for erectile dysfunction and prostate abnormalities overtime. STRENGTHS & LIMITATIONS: The study simultaneously examined several endpoints with validated instruments within 2 different male populations, 1 with SD and 1 with infertility. As for limitations, there is no consensus in the scientific community regarding the definition of MHO, and the results are derived from patients with SD or infertility, which could have different characteristics than the general male population. CONCLUSION: MHO is associated with subclinical ED, increased cardiovascular risk, and prostate enlargement. Lotti F, Rastrelli G, Maseroli E, et al. Impact of Metabolically Healthy Obesity in Patients with Andrological Problems. J Sex Med 2019:16;821-832.

Changes in testicular size, echotexture, and arterial blood flow associated with the attainment of puberty in Dorper rams raised in a subtropical climate.

There is a paucity of information on the relationships of testicular morphology, echotextural attributes, and blood flow dynamics with pubertal development of rams raised in a subtropical climate. Forty-five Dorper rams (24 rams aged 8-11 months and 21 rams aged 12-24 months) were examined using a portable ultrasound scanner connected to a 7.5-MHz transducer. Computer-assisted analyses of testicular ultrasonograms utilized commercially available Image ProPlus® analytical software. Spectral Doppler scans of testicular arteries were performed immediately after scrotal (B-mode) ultrasonography to determine peak systolic velocity (PSV), end-diastolic velocity (EDV), resistive index (RI = [PSV-EDV]/PSV), and pulsatility index (PI = [SPV-EDV]/mean velocity) of the blood vessels. The length of the testes (9.7 ± 0.3 compared with 9.0 ± 0.2 cm) and scrotal circumference (33.3 ± 0.5 compared with 31.8 ± 0.4 cm) were greater (p < 0.05) but testicular depth (4.5 ± 0.1  compared with 4.9 ± 0.08 cm) was less (p < 0.05) in sexually mature compared with peripubertal rams. [Corrections added on 9 Jan 2019 after initial online publication: The testicular size values in the sentence were corrected.] There were no differences (p > 0.05) between the two age groups of Dorper rams in blood flow indices of testicular arteries. Mean numerical pixel values (100.5 ± 4.1 compared with 89.2 ± 4.8) and pixel heterogeneity (25.6 ± 0.6 compared with 23.6 ± 0.5) of testicular parenchyma were greater (p < 0.05) in peripubertal than in postpubertal rams. Semen volume was negatively correlated with PI of testicular arteries (r = -0.57, p = 0.04). In summary, the attainment of sexual maturity in the rams of the present study was associated with significant changes in testicular length and depth, scrotal circumference, and parenchymal echogenicity/hetrogeneity but not in testicular volume and blood perfusion rates. Testicular artery PI can be used to predict the volume of ejaculate in rams.

Reproductive characteristics of bulls from two breed compositions and their correlations with infrared thermography.

The objective was to evaluate reproductive characteristics of crossbred Girolando (Gyr x Holstein) bulls from two breed compositions and correlate these results with infrared thermography data. Evaluations were performed considering sperm motility, vigor and morphology; scrotal circumference; body morphology and temperament. Infrared thermography was performed to determine surface temperatures of ocular and scrotal areas. Thermoregulation capacity was assessed by differences between air and rectal temperatures, air and maximum temperatures in ocular and scrotal areas, and dorsal and ventral lines of the scrotum. Data analysis was performed using a linear mixed model (breed composition as fixed effect and year of evaluation as random effect). Spearman correlation coefficient was used to associate thermography and reproductive data. Girolando 3/4 Holstein bulls had higher (P ≤ 0.001) scrotal circumference and higher average body morphology and temperament, whereas 5/8 Holstein bulls had a higher (P < 0.001) percentage of major-type and total sperm defects. Girolando 3/4 Holstein bulls had scrotal temperatures 0.8 °C higher (P < 0.001) and 5/8 Holstein bulls had 9.8% and 10.6% higher differences on "rectal - scrotal area" and "ocular area - scrotal area" temperatures, respectively. Ocular area temperatures had negative correlations (P ≤ 0.1) with sperm motility and vigor, and positive correlations (P < 0.001) with minor-type and total sperm defects. Ventral line scrotal temperatures had positive correlations (P < 0.001) with minor-type and total sperm defects. Girolando 3/4 Holstein bulls were found to be superior to 5/8 Holstein bulls for reproductive characteristics. Under non-stressing climatic conditions, semen characteristics of Girolando bulls were more influenced by breed composition than by the capacity for scrotal thermoregulation. Correlations between semen quality and scrotal temperatures can aid in the identification of bulls for breeding, particularly when a large number of animals are in the tests.

Testicular thermoregulation, scrotal surface temperature patterns and semen quality of water buffalo bulls reared in a tropical climate.

This study evaluated the capacity of thermoregulation and its consequences on the scrotal surface temperature patterns and semen quality of buffalo bulls raised in a wet tropical climate. Eleven water buffaloes were evaluated in the rainiest, in the transitional and in the less rainy season. Air temperature and humidity were consistently high, but the animals did not show thermal stress in any season. The scrotal temperature gradient of buffalo bulls using infrared thermography was described, and three parallel and decreasing thermal bands were characterised. Sperm quality (n = 176 ejaculates) was maintained in normal parameters over the periods. Pearson's coefficients showed that sperm volume and progressive motility were negatively correlated with ocular globe, epididymal tail and minimum scrotal temperatures (p < .01). Sperm membrane integrity was negatively influenced by increases in epididymal tail and minimum scrotal temperatures (p < .01). Ocular globe temperature also showed positive correlation with rectal, spermatic cord, and epididymal tail temperatures (p < .01). Therefore, even under high temperature and humidity, the thermoregulatory system was effective in preventing heat stress and the normality of scrotal surface temperatures, spermatogenesis and sperm maturation were maintained.

Scrotal infrared digital thermography predicts effects of thermal stress on buffalo (Bubalus bubalis) semen.

The objective was to use scrotal infrared digital thermography to evaluate effects of thermal stress on semen quality of Murrah buffalo (Bubalus bubalis) breeding bulls. Ejaculates from 109 Murrah bulls maintained at three semen stations were evaluated for: ejaculate volume, sperm concentration (SCON), initial motility (IM), percent live sperm (LIVE), acrosome integrity of fresh semen (AIFS), plasma membrane integrity of fresh semen (PMIFS), head abnormalities of fresh semen (HAFS), midpiece abnormalities of fresh semen (MPAFS), tail abnormalities of fresh semen (TAFS), post-thaw motility (PTM), acrosome integrity of post-thawed semen (AIPT) and plasma membrane integrity of post-thawed semen (PMIPT). Scrotal and ocular surface temperatures were acquired during rainy, winter and summer seasons, using an FLIR i5 infrared camera. Thermographic images were analyzed with Quick Report 1.2 SP2 software and temperature data acquired. Daily mean temperature and mean relative humidity were used to determine the temperature-humidity index (THI). Environmental factors were analyzed using CORR to determine collinearity among independent variables. There was a high correlation among THI, proximal, mid and distal scrotal temperatures (r ≥ 0.73). Therefore, distal pole temperature (DPT), THI, temperature gradient (TG) and ocular temperature (OcT) were used in the analysis of variance (ANOVA) and in regression analysis of dependent variables. The THI, DPT, TG and OcT had significant influences on sperm abnormalities, acrosome and plasma membrane integrity of fresh as well as post-thawed semen. The TG had significant effects on LIVE and SCON. All semen quality parameters were predicted (regression analysis) as a function of the three independent factors. We concluded that scrotal infrared thermography was useful for assessing influences of thermal stress and environmental factors on characteristics of buffalo semen.

Capsaicin attenuates spermatogenic cell death induced by scrotal hyperthermia through its antioxidative and anti-apoptotic activities.

This study was performed to examine whether capsaicin, the main pungent ingredient of red peppers, exerts protective effects against testicular injuries induced by transient scrotal hyperthermia. Capsaicin (0.33 mg kg-1 ) was administered subcutaneously to mice one hour before heat stress (HS) in a 43°C water bath for 20 min. After 7 days, mice exposed to HS showed low testicular weight, severe vacuolisation of seminiferous tubules followed by loss of spermatogenic cells, and appearance of multinucleated giant cells and remarkable TUNEL-positive apoptotic cells, as well as weak immunoreactivity of phospholipid hydroperoxide glutathione peroxidase (PHGPx) in spermatogenic cells. Levels of lipid peroxidation and heat shock 70-kDa protein 1 (Hsp72) and BCL2-associated X protein (Bax) mRNA were greatly increased, but PHGPx, manganese superoxide dismutase (MnSOD), and B-cell lymphoma-extra large (Bcl-xL) mRNAs were significantly diminished in the testes by HS. However, capsaicin pre-treatment significantly suppressed the spermatogenic cell death, oxidative stress (levels of MDA, PHGPx immunoreactivity, and Hsp72, PHGPx, and MnSOD mRNA) and apoptosis (levels of TUNEL-positive cells, and Bcl-xL and Bax mRNA) in testes by HS. These suggest that capsaicin has a protective effect against spermatogenic cell death induced by scrotal hyperthermia through its antioxidative and anti-apoptotic activities.

Thermoregulation of the bovine scrotum 1: measurements of free-range animals in a paddock and pen.

The bull's scrotum and scrotal cord vasculature has traditionally been regarded as a thermoregulatory device for maintaining optimal testicular temperature for normal spermatogenesis. This assumption has mostly been derived from discrete measurements using thermocouples with limited data correlating continuous scrotal temperature (ST) to body temperature (BT). From mid-summer to early autumn, four Wagyu bulls (9-18 months) were surgically implanted with two data loggers (DL) logging at 30 min intervals: one on the right hand side flank and the other was attached to the visceral vaginal tunic of the mid-testis. Bulls were firstly housed in a paddock (PK) for 13 days and then moved to individual pens (IP), again for 13 days. Repeated measures analysis modelled the long-term and diurnal trends in BT and ST. While both day and time of day (TOD) were significant effects for ST at both housing locations (P < 0.005), only TOD showed significance for BT at both locations (P < 0.0001). Significant effects were seen between bulls with ST (F = 167.2, P < 0.001) but not BT (F = 0.03, P = 0.863), suggestive of variation in individual bull thermoregulatory capacity. Dual peaks were observed in ST at 0500 and 2130 h when housed in PK but not IP, suggesting ST may be influenced by external stimuli such as postural or behavioural changes. Reporting concurrent and continuous BT and ST will allow further investigation into factors influencing bovine ST and should be useful in selecting bulls with high degrees of thermoregulation capacity.

Measurement of bovine body and scrotal temperature using implanted temperature sensitive radio transmitters, data loggers and infrared thermography.

Synchronous and continuous measurement of body (BT) and scrotal temperature (ST) without adverse welfare or behavioural interference is essential for understanding thermoregulation of the bull testis. This study compared three technologies for their efficacy for long-term measurement of the relationship between BT and ST by means of (1) temperature sensitive radio transmitters (RT), (2) data loggers (DL) and (3) infrared imaging (IRI). After an initial pilot study on two bulls to establish a surgical protocol, RTs and DLs were implanted into the flank and mid-scrotum of six Wagyu bulls for between 29 and 49 days. RT frequencies were scanned every 15 min, whilst DLs logged every 30 min. Infrared imaging of the body (flank) and scrotum of each bull was recorded hourly for one 24-h period and compared to RT and DL data. After a series of subsequent heat stress studies, bulls were castrated and testicular tissue samples processed for evidence of histopathology. Radio transmitters were less reliable than DLs; RTs lost >11 % of data, whilst 11 of the 12 DLs had 0 % data loss. IRI was only interpretable in 35.8 % of images recorded. Pearson correlations between DL and RT were strong for both BT (r > 0.94, P < 0.001) and ST (r > 0.80, P < 0.001). Surgery produced temporary minor inflammation and scrotal hematoma in two animals post-surgery. Whilst scar tissue was observed at all surgical sutured sites when bulls were castrated, there was no evidence of testicular adhesion and normal active spermatogenesis was observed in six of the eight implanted testicles. There was no significant correlation of IRI with either DL or RT. We conclude that DLs provided to be a reliable continuous source of data for synchronous measurement of BT and ST.

Influence of season, age and management on scrotal thermal profile in Murrah bulls using scrotal infrared digital thermography.

The aim of the present study was to examine the effects of non-genetic factors on scrotal thermographic profile viz., proximal pole temperature (PPT °C), mid pole temperature (MPT °C), distal pole temperature (DPT °C) and ocular temperature (OcT) of Murrah (Bubalus bubalis) breeding bulls. A total of 109 buffalo bulls, maintained at three semen stations (SS), were monitored for scrotal surface and ocular temperatures using infrared thermography twice daily during rainy, winter and summer seasons using an FLIR i5 infrared camera and temperatures were measured. Thermograms were analysed by FLIR QuickReport v.1.2 SP2 software. Statistical analysis revealed that semen station, season, temperature humidity index (THI), housing system and timing of observations had significant (P < 0.05) effect on scrotal surface temperature (SST) and OcT. In SS-I, the PPT and MPT were significantly (P < 0.05) higher as compared to SS-II and SS-III. THI had significant (P < 0.05) effect on SST and OcT, whereas PPT (°C), MPT (°C), DPT (°C) and OcT (°C) values during high THI (>80.88; <0.05) period were higher as compared to medium THI period (70.06-80.88) and during low THI period (<70.06). Temperature gradient (TG) of the testes was significantly (P < 0.05) higher during low THI period (4.50 ± 0.06 °C) as compared to medium THI (2.38 ± 0.03 °C) and high THI (1.61 ± 0.05 °C). Season of the year had a significant effect (P < 0.05) on the SST and OcT. During the rainy season, PPT (34.50 ± 0.09 °C), MPT (33.44 ± 0.12 °C) and DPT (32.11 ± 0.15 °C) were significantly (P < 0.05) higher as compared to winter and summer seasons. Age of the bulls had non-significant effect on SST and OcT but had a marked influence on thermal profile of scrotum. It could be concluded semen station, season, temperature humidity index, housing system and timing of observations had a significant influence on scrotal surface temperature. The monitoring of scrotal surface temperature by infrared thermography was found to be useful in evaluating the effects of thermal stress on physiology and health of buffalo bulls.

Activity of the external urethral sphincter evoked by genital stimulation in male rats.

AIMS: To determine whether the external urethral sphincter (EUS) fasciculi of male rats respond to the mechanical stimulation of genital structures and to characterize the pattern of the electromyographic (EMG) activity of the three regions of the EUS: the cranial (CrEUS), the medial (MeEUS) and the caudal (CaEUS). METHODS: Electromyographic signals were recorded from the CrEUS, MeEUS and CaEUS regions of the male rat's EUS, before, during and after the mechanical stimulation of the urogenital structures. RESULTS: The CrEUS, MeEUS and CaEUS regions responded when brushing and squeezing the foreskin and glans as well as to penile and prostatic urethral distension. The CaEUS EMG amplitude (P < 0.01) and frequency (P < 0.05) were lower in comparison to the CrEUS and MeEUS responses to the mechanical stimulation. In addition, the CaEUS was characterized by a short or no afterdischarge. In contrast, the CrEUS and MeEUS responded by presenting a long discharge after the penile or prostatic urethral distension. CONCLUSIONS: The activity of the EUS is modulated by both, cutaneous and visceral genitourinary stimuli, with motor units being activated by mechanoreceptors located in the foreskin, glans, bladder, and urethra. The CrEUS, MeEUS and CaEUS have differential EMG patterns, indicating that the EUS consists of three anatomically and functionally different regions. Precise coordination in the muscular activity of these regions may be crucial for the control of male expulsive urethral functions, i.e., during voiding and ejaculation. Neurourol. Urodynam. 35:914-919, 2016. © 2015 Wiley Periodicals, Inc.