Interleukin-6 supplementation improves bovine conceptus elongation and transcriptomic indicators of developmental competence†.

A high incidence of pregnancy failures occurs in cattle during the second week of pregnancy as blastocysts transition into an elongated conceptus. This work explored whether interleukin-6 supplementation during in vitro embryo production would improve subsequent conceptus development. Bovine embryos were treated with 0 or 100 ng/mL recombinant bovine interleukin-6 beginning on day 5 post-fertilization. At day 7.5 post-fertilization, blastocysts were transferred into estrus synchronized beef cows (n = 5 recipients/treatment, 10 embryos/recipient). Seven days after transfer (day 14.5), cows were euthanized to harvest reproductive tracts and collect conceptuses. Individual conceptus lengths and stages were recorded before processing for RNA sequencing. Increases in conceptus recovery, length, and the proportion of tubular and filamentous conceptuses were detected in conceptuses derived from interleukin-6-treated embryos. The interleukin-6 treatment generated 591 differentially expressed genes in conceptuses (n = 9-10/treatment). Gene ontology enrichment analyses revealed changes in transcriptional regulation, DNA-binding, and antiviral actions. Only a few differentially expressed genes were associated with extraembryonic development, but several differentially expressed genes were associated with embryonic regulation of transcription, mesoderm and ectoderm development, organogenesis, limb formation, and somatogenesis. To conclude, this work provides evidence that interleukin-6 treatment before embryo transfer promotes pre-implantation conceptus development and gene expression in ways that resemble the generation of a robust conceptus containing favorable abilities to survive this critical period of pregnancy.

Gamma-band Intermuscular Connectivity Is Associated With Increased Neural Drive to Pelvic Floor Muscles in Women With Interstitial Cystitis/Bladder Pain Syndrome.

PURPOSE: Interstitial cystitis/bladder pain syndrome patients can experience overactive pelvic floor muscle activity at rest. While the frequency power spectrum of pelvic floor muscle has briefly been explored, intermuscular connectivity of the pelvic floor muscle has yet to be studied, which may provide useful insight into the neurological component, ie, neural drive to muscles, in interstitial cystitis/bladder pain syndrome. MATERIALS AND METHODS: High-density surface electromyography was collected from 15 female interstitial cystitis/bladder pain syndrome patients with pelvic floor tenderness and 15 urologically healthy female controls. Intermuscular connectivity was calculated across the maximally active locations of the left and right sides of the pelvic floor muscle as identified from the root mean squared amplitude at rest and compared with Student t tests for common sensorimotor rhythms involved in motor control: alpha (8-12 Hz), beta (13-30 Hz), and gamma (31-70 Hz) frequency bands. The root mean squared amplitudes at rest were also compared across groups. RESULTS: The resting root mean squared amplitude of the pelvic floor muscle was significantly greater in female interstitial cystitis/bladder pain syndrome patients compared to healthy female controls (P = .0046). The gamma-band intermuscular connectivity was significantly different between rest and pelvic floor muscle contraction (P = .0001) for healthy female controls, but not for female patients with interstitial cystitis/bladder pain syndrome (P = .1214). Both results indicate an elevated neural drive to pelvic floor muscle at rest in female interstitial cystitis/bladder pain syndrome patients. CONCLUSIONS: Gamma-band pelvic floor muscle connectivity in female interstitial cystitis/bladder pain syndrome patients is increased at rest. The results of this study may provide insight into the impaired neural drive to pelvic floor muscle implicated with interstitial cystitis/bladder pain syndrome.

High-density surface electromyographic assessment of pelvic floor hypertonicity in IC/BPS patients: a pilot study.

INTRODUCTION AND HYPOTHESIS: To assess the feasibility of objectively assessing pelvic floor hypertonicity (PFH) in women with interstitial cystitis/bladder pain syndrome (IC/BPS) using an intra-vaginal high-density surface electromyography (HD-sEMG) probe. METHODS: Seven female subjects (mean age 44 ± 13 years) with a prior diagnosis of IC/BPS were recruited. A full digital pelvic examination was administered to identify hypertonic muscles. Intra-vaginal HD-sEMG was acquired during rest. Root-mean-squared (RMS) amplitude during rest was calculated for each channel to define a hypertonicity index and hypertonic zone. Innervation zones (IZs) were identified from the bipolar mapping of decomposed HD-sEMG signals and summarized into an IZ distribution mapping. RESULTS: Of the seven subjects recruited, five had normal pelvic floor muscle tone and two exhibited hypertonicity upon muscle palpation. Subjects with PFH demonstrated a higher hypertonicity index (12.6 ± 3.5 vs. 4.5 ± 1.2) in sessions 1 and 2. The hypertonic zone defined by the 64-channel RMS mapping coincided with the digital pelvic examination findings. The corresponding IZs were localized for each motor unit. The hypertonicity indices between two consecutive sessions were well correlated (CC = 0.95). CONCLUSIONS: This study represents the first effort to employ intra-vaginal HD-sEMG to assess PFH in women with IC/BPS. Our results demonstrate the feasibility of HD-sEMG to provide a quantitative diagnosis of PFH and the precise localization of hypertonic muscles and IZs. The proposed HD-sEMG-based techniques provide promising tools for clinical diagnosis and treatment of PFH, such as the personalized guidance of BoNT injections.

High-Density Surface Electromyography Assessment of Pelvic Floor Dysfunction in Women with Interstitial Cystitis/Bladder Pain Syndrome.

PURPOSE: Up to 85% of women with interstitial cystitis/bladder pain syndrome have pelvic floor dysfunction and hypertonicity. Current evaluation methodologies lack objective measures of pelvic floor muscle activity. We examined the ability of using intravaginal high-density surface electromyography to quantitatively, objectively and noninvasively map pelvic floor muscle activity and innervation zone locations in patients with interstitial cystitis/bladder pain syndrome. MATERIALS AND METHODS: Fifteen women with interstitial cystitis/bladder pain syndrome and 15 controls underwent 2 sessions of digital pelvic examinations and high-density surface electromyography assessments. The root mean squared amplitude of high-density surface electromyography was first calculated, and the resting root mean squared ratio was then calculated by normalizing the resting electromyography root mean squared to the peak electromyography amplitude reached during maximum voluntary contraction. Innervation zone distributions were obtained from decomposed high-density surface electromyography signals. The correlation between the root mean squared ratio and interstitial cystitis/bladder pain syndrome symptom scores and pelvic floor muscle alignment were investigated in patients with interstitial cystitis/bladder pain syndrome and healthy controls. RESULTS: Women with interstitial cystitis/bladder pain syndrome demonstrated significantly increased resting root mean squared ratios compared to controls (0.155±0.048 vs 0.099±0.041, p=0.0019). Significant correlations were found between resting root mean squared ratio and patient reported pain (rs=0.523, p=0.003), interstitial cystitis symptom (rs=0.521, p=0.003) and problem indices (rs=0.60, p <0.001). In addition, women with interstitial cystitis/bladder pain syndrome were more likely to have shortened pelvic floor muscles (80%, 12 vs 13.3%, 2, p <0.01). Women with shortened pelvic floor muscles demonstrated significantly higher resting root mean squared ratio compared to those with normal pelvic floor muscle length (0.155±0.046 vs 0.107±0.040, p=0.0058). CONCLUSIONS: Intravaginal high-density surface electromyography offers an objective and quantitative strategy to noninvasively assess pelvic floor muscle dysfunction in women with interstitial cystitis/bladder pain syndrome. Abundant spatiotemporal muscle activity information captured by high-density surface electromyography allows for mapping innervation zone distributions for major pelvic floor muscles.

Neural control properties of the external anal sphincter in young and elderly women.

AIMS: The prevalence of fecal incontinence (FI) increases with age and affects more than 15% of the elderly population. Sarcopenia, skeletal muscle structural, and functional decline with aging, is known to be caused by neuromuscular dysfunction. However, age-related alterations of the neuromuscular function of the external anal sphincter (EAS) have not been studied. This study aims to quantitatively characterize the effect of aging on the EAS by assessing the firing patterns and size of motor unit action potential (MUAP) using high-density surface electromyography (HD-sEMG) recording and analysis techniques. METHODS: Thirteen young (31.0 ± 3.6 years) and 14 elderly (64.3 ± 6.2 years) healthy women were recruited for this study. EMG activity of the EAS during maximal voluntary contraction was recorded by a 64-Channel, HD-sEMG intra-rectal probe. HD-sEMG signals were decomposed into MUAP spike trains to extract the firing rate and amplitudes thereof. RESULTS: HD-sEMG decomposition was successfully performed. For the young and elderly groups, mean motor unit (MU) firing rates of 11.4 ± 2.1 pulses per second (PPS) and 9.6 ± 2.3 PPS, and mean MUAP amplitudes of 45.2 ± 14.3 µV and 61.9 ± 21.2 µV were respectively obtained. Both the MU firing rate and MUAP amplitude were significantly different between two groups (P < .05). Moreover, the MUAP firing rate and amplitude correlated with age with a linear regression model (P < .05). CONCLUSIONS: This study represents the first effort to examine the effect of aging on the neuromuscular function of EAS. Results suggest an age-related impairment of lower motor neuron descending excitation to the EAS with a compensatory increase in mean MU size.

Effects of delivery mode and age on motor unit properties of the external anal sphincter in women.

INTRODUCTION AND HYPOTHESIS: This study aimed to assess the individual and interactive effects of delivery mode and age on the function of the external anal sphincter (EAS) by analyzing the motor unit properties with intramuscular electromyography (EMG). Results are expected to improve the understanding of delivery-related occult obstetric EAS injuries and its development over the aging process and further support early clinical detection and intervention. METHODS: A total of 49 postpartum women were recruited into four test groups according to their age and delivery mode: young vaginal delivery (Y-VD), elderly vaginal delivery (E-VD), young cesarean section (Y-CS), and elderly cesarean section (E-CS) groups. Anorectal ultrasonography, manometry, and intramuscular EMG were employed for comprehensive evaluation of EAS function. RESULTS: No significant difference in anorectal ultrasonography and most manometry measurements was associated with delivery age or mode. Intramuscular EMG, however, revealed a statistically significant difference in the characteristics of motor unit potentials (MUPs), including duration, turns, phases, and multiphase wave ratio between four subject groups. No significant interaction effect between age and delivery mode was found. CONCLUSIONS: Delivery mode and age have a significant effect on the neuromuscular function of the EAS, suggesting a potential protectiveness of cesarean section against impairment to the EAS. Our results do not provide significant evidence regarding the interaction effect of delivery mode and age; further investigations are needed to confirm this conclusion.

Innervation asymmetry of the external anal sphincter in aging characterized from high-density intra-rectal surface EMG recordings.

AIMS: The innervation zone asymmetry of the external anal sphincter (EAS) has been investigated as a risk factor for the development of fecal incontinence (FI). This study aims to utilize an intra-rectal high-density surface electromyogram (HD-sEMG) recording and advanced HD-sEMG decomposition technique to characterize the effects of aging on the asymmetry of EAS functional innervation. METHODS: HD-sEMG signals were recorded intra-rectally from six healthy young and seven healthy elderly women during voluntary contractions of the EAS. EMG signals were decomposed into constituent motor unit action potentials (MUAPs) and the innervation zone of each decomposed motor unit was identified. Asymmetry index (AI) was defined and calculated for all subjects. The maximum squeezing pressures of the EAS were also measured for all subjects as a comparison. RESULTS: The HD-sEMG decomposition and AI calculation were successfully performed from EMG data acquired from all the subjects. The AI values were 28.7 ± 17.0% for the young group and 55.6 ± 18.8% for the elderly group. The AI and EAS contraction strength were found to be negatively correlated (P < 0.05). A two-tailed student's t-test demonstrated a significant increase in AI with age by comparison between two groups (P < 0.05). CONCLUSIONS: Our work demonstrates, for the first time, that EAS functional innervation tends to become increasingly asymmetrical with advancing age, and this increase is associated with a compromised anorectal function. Results suggest that the intra-rectal HD-sEMG will serve as an advanced tool for assessing and monitoring the anorectal neuromuscular function minimally invasively under different pathophysiological conditions.

Effects of Type II Diabetes on Proprioception during a Reach to Pinch Task.

Older adults with type II diabetes (T2D) are at risk of developing nerve disorders that result in functional impairment. Most work in proprioceptive dysfunction in older adults with T2D has focused on functional deficits of the lower limb. The purpose of this study was to examine proprioceptive effects of T2D on the upper limb in older adults. Kinematic performance of a reach-to-pinch action toward a virtual target was assessed in a T2D group (60+ years old with T2D) and a healthy age- and sex-matched control group. Tactile and vibratory thresholds did not differ between T2D and controls. Task accuracy via mean pinch location was significantly worse for persons with T2D (pwT2D) with differences in wrist extension/flexion (ex/fl), wrist abduction/adduction (ab/ad), 1st carpometacarpal (CMC) ab/ad, 2nd metacarpophalangeal (MCP2) ex/fl, MCP2 ab/ad, and digit 1 and hand transport trajectories. Group differences persisted with consideration of body mass index; sex differences in task accuracy emerged. Findings indicate that proprioception of the upper extremity is altered in pwT2D such that they exhibit a unique aperture position and aiming strategy during a reach-to-pinch action. These findings characterize functional sensorimotor impairment of the upper limb in pwT2D with respect to workspaces without visual or tactile feedback.

Image Segmentation for High-Density Surface Electromyography Mappings of Pelvic Floor Muscle Activity of Women with Interstitial Cystitis/Bladder Pain Syndrome.

Interstitial cystitis/bladder pain syndrome (IC/BPS) can result in pelvic floor muscle (PFM) overactivity. Current clinical assessment protocols include basic electromyographic assessment of PFM activation; however, they do not provide a comprehensive assessment localized to each region of the PFM. We examined the ability of high-definition features from intravaginal high-density surface electromyography (HD-sEMG) to assess the severity of PFM overactivity in female IC/BPS patients. HD-sEMG was collected from fifteen female IC/BPS patients and fifteen urologically healthy female controls. The 2D mappings of root mean squared amplitude (RMS) at rest normalized by maximal voluntary contraction (resting RMS ratios) were segmented via k-means to identify areas of peak activity and surrounding activity. Female IC/BPS patients exhibited significantly greater resting RMS ratios for peak activity (p=0.0096), surrounding activity (p=0.0003), and average activity (p=0.0016) compared to healthy female controls. Furthermore, the area of peak activity was significantly larger for female IC/BPS patients than for healthy female controls (p=0.0063). Image segmentation of intravaginal HD-sEMG provides a more robust biomarker of PFM as compared to current methods.

Evaluation of the stress-reducing effect of trace mineral injection in beef calves.

BACKGROUND: Little is known about the effects of trace mineral supplementation on the stress response in beef calves. OBJECTIVES: To investigate the effect of injectable trace mineral supplementation (ITM) on the stress response in beef calves exposed to different types of stress. ANIMALS: Thirty weaned Angus and Angus crossbred calves. METHODS: The enrolled calves were randomly assigned to 2 groups: ITM, 15 calves received modified-live virus vaccine (MLV) and ITM SC and 15 calves received MLV and saline SC (CONT). The calves were exposed to 3 types of stress: the stress of MLV vaccination (d0), nasal aerosol with bovine viral diarrhea virus-2 (BVDV-2) challenge (d5), and liver biopsy (d26). The calves' body weights and health status were monitored. Leukocyte counts, serum cortisol concentration ([cort]), BVDV-2 serum neutralizing antibodies (SNA), and percentages of CD4+ , CD8+ , WC1+ , and CD25+ T-lymphocytes were measured. RESULTS: Serum cortisol concentration ([cort]) showed strong associations with the percentage of CD8+ (rs = .50), BVDV2-SNA (rs = -.43), and WC1CD25+ (rs = .41) cells, and rectal temperature (rs = .40). The highest [cort] was reported 3 days after aerosol BVDV-2 challenge. Serum [cort] was decreased in ITM-treated calves 3 days post-BVDV-2 challenge, compared with CONT calves, with an average decrease of 18.5 ng/µL (95% confidence interval [CI], -6.07 to -31.3). The ITM-treated calves were heavier and healthier (P < .01) than the CONT calves. CONCLUSIONS AND CLINICAL IMPORTANCE: Trace mineral supplementation appears to have stress mitigation effects in beef cattle that may reflect positively on growth and health performance. Viral exposure is associated with a high degree of stress, which is considered a major welfare concern.

Reproductive and lactational responses of multiparous dairy cattle to short-term postpartum chromium supplementation during the summer months.

The objective of this work was to evaluate the potential benefits of short-duration, high-dose chromium (Cr) supplementation in early postpartum dairy cows during the summer months. Multiparous, early-lactation cows (20.95 ± 0.21 d in milk) were assigned to 1 of 2 treatment groups: (1) control diet (Con; n = 10) or (2) control diet + Cr propionate (CrPro; 12 mg/head per day Cr; n = 12). Measurements of ovarian structures, respiration rates (RR), rectal temperatures (RT), and blood glucose concentrations were recorded every 3 d. Blood was also collected for analysis of plasma progesterone concentrations. Every 6 d, in conjunction with ultrasonography, endometrial cytology samples were collected via cytobrush from each cow to determine the incidences of subclinical endometritis, as determined by polymorphonuclear leukocyte (PMNL)%. No differences were detected in RR, RT, blood glucose, feed intake, milk yield, or change in body weight. The supplementation did, however, improve some reproductive parameters. At cytology sample 6, the PMNL% increased in Con cows, and was greater than the PMNL% in the CrPro group. Chromium consumption did not affect the number or size of most follicles, with the exception being the 6 to 9 mm category where the CrPro group had a greater average diameter and tended to have greater numbers of follicles in this category. While corpus luteum numbers and size did not differ between treatments, the ratio of progesterone to average corpus luteum volume was greater in the CrPro group compared with the Con group. The results from this study indicate that, whereas the short-term, high-dose supplementation strategy did not affect feed intake or milk yield, this Cr supplementation strategy could benefit reproductive performance during periods of stress.

Customizable, reconfigurable, and anatomically coordinated large-area, high-density electromyography from drawn-on-skin electrode arrays.

Accurate anatomical matching for patient-specific electromyographic (EMG) mapping is crucial yet technically challenging in various medical disciplines. The fixed electrode construction of multielectrode arrays (MEAs) makes it nearly impossible to match an individual's unique muscle anatomy. This mismatch between the MEAs and target muscles leads to missing relevant muscle activity, highly redundant data, complicated electrode placement optimization, and inaccuracies in classification algorithms. Here, we present customizable and reconfigurable drawn-on-skin (DoS) MEAs as the first demonstration of high-density EMG mapping from in situ-fabricated electrodes with tunable configurations adapted to subject-specific muscle anatomy. The DoS MEAs show uniform electrical properties and can map EMG activity with high fidelity under skin deformation-induced motion, which stems from the unique and robust skin-electrode interface. They can be used to localize innervation zones (IZs), detect motor unit propagation, and capture EMG signals with consistent quality during large muscle movements. Reconfiguring the electrode arrangement of DoS MEAs to match and extend the coverage of the forearm flexors enables localization of the muscle activity and prevents missed information such as IZs. In addition, DoS MEAs customized to the specific anatomy of subjects produce highly informative data, leading to accurate finger gesture detection and prosthetic control compared with conventional technology.

Delayed processing of blood samples impairs the accuracy of mRNA-based biomarkers.

The transcriptome of peripheral white blood cells (PWBCs) are indicators of an organism's physiological state, thus making them a prime biological sample for mRNA-based biomarker discovery. Here, we designed an experiment to evaluate the impact of delayed processing of whole blood samples on gene transcript abundance in PWBCs. We hypothesized that storing blood samples for 24 h at 4 °C would cause RNA degradation resulting in altered transcriptome profiles. There were no statistical differences in RNA quality parameters among samples processed after one, three, six, or eight hours post collection. Additionally, no significant differences were noted in RNA quality parameters or gene transcript abundance between samples collected from the jugular and coccygeal veins. However, samples processed after 24 h of storage had a lower RNA integrity number value (P = 0.03) in comparison to those processed after one hour of storage. Using RNA-sequencing, we identified four and 515 genes with differential transcript abundance in samples processed after storage for eight and 24 h, respectively, relative to samples processed after one hour. Sequencing coverage of transcripts was similar between samples from the 24-h and one-hour groups, thus showing no indication of RNA degradation. This alteration in transcriptome profiles can impair the accuracy of mRNA-based biomarkers, therefore, blood samples collected for mRNA-based biomarker discovery should be refrigerated immediately and processed within six hours post-sampling.

Evaluating the use of luteal color Doppler ultrasonography and pregnancy-associated glycoproteins to diagnose pregnancy and predict pregnancy loss in Bos taurus beef replacement heifers.

The objective of this study was to evaluate the use of corpus luteum (CL) color Doppler (CD) ultrasonography and pregnancy-associated glycoproteins (PAG) for early pregnancy diagnosis and examine their ability to predict late embryonic/early fetal mortality (LEM) in Bos taurus beef replacement heifers. Beef heifers (n = 178) were exposed to a 7-d CO-Synch + CIDR protocol followed by fixed-time artificial insemination (day 0). On days 20 and 22, B-mode and CD ultrasonography were performed to evaluate CL morphometries and blood perfusion, respectively. Heifers were considered nonpregnant when CL area was <2 cm2 or estimated luteal blood perfusion was ≤30% of the total luteal area. Blood samples were collected on days 25 and 29 to estimate circulating concentrations of PAG. Conventional ultrasonography on days 29 and 94 was utilized to determine pregnancy status and considered the gold standard method for pregnancy diagnosis. Pregnant heifers had greater (P < 0.01) CL diameter, area, volume, and blood perfusion when compared with nonpregnant heifers on days 20 and 22. Accuracy of CD on days 20 and 22, and PAG on days 25 and 29 were 91%, 94%, 96%, and 98%, respectively. No false-negative results were observed for CD on both days 20 and 22 (negative predicted value = 100%) and false-positive results represented 8% and 6% of the diagnoses. Heifers that experienced LEM between days 29 and 94 of gestation had decreased luteal (P = 0.02) volume on day 20 and tended (P = 0.07) to have decreased concentrations of PAG on day 29 compared with heifers that maintained pregnancy. However, both CD and PAG failed to predict embryonic mortality. In conclusion, CD successfully detected most nonpregnant replacement heifers as early as day 20 of gestation, while resulting in no false negative diagnoses. Both CD and PAG failed to predict LEM in the present study.

Identifying nonpregnant females early after breeding allows cattle producers to rapidly rebreed females that failed to conceive after their first artificial insemination and consequently increases reproductive efficiency. Additionally, embryonic and fetal mortality during early gestation are the main drivers of pregnancy failure and represents a significant economic burden to both the beef and dairy industries. This study evaluated the use of color Doppler (CD) ultrasonography of specific ovarian structures and blood concentrations of pregnancy-associated glycoproteins (PAG) as potential methods to diagnose pregnancy earlier than industry-standard techniques. Moreover, the present study investigated the use of CD and blood PAG as predictor of pregnancy loss. Data generated here indicates that CD and blood PAG can accurately detect pregnancy as early as 20 and 25 d after insemination, respectively. In the present study, heifers that experienced pregnancy loss between days 29 and 94 of gestation tended to have decreased plasma concentrations of PAG during early pregnancy. Heifers experiencing pregnancy loss between days 29 and 94 of gestation were also more likely to have a luteal cavity on day 20 of gestation and had decreased luteal volume on the same day. However, results reported herein indicate that both CD and blood concentrations of PAG failed to predict pregnancy loss in replacement heifers.

Effects of temperament on reproductive performance of Bos taurus heifers enrolled in the 7-day CO-Synch + controlled internal drug release protocol.

Cattle temperament significantly impacts production traits such as reproduction. The objective of this study was to assess the effects of temperament on pregnancy rates to fixed-timed artificial insemination (TAI) in Bos taurus beef heifers. A total of 297 Angus influenced heifers from 3 different locations were evaluated for temperament based on chute score and exit velocity on the first day of the estrus synchronization protocol (d-9) and classified by temperament type based on temperament score (calm ≤ 3 < excitable). Pregnancy status was determined by transrectal ultrasonography approximately 40 d after TAI. Hair from the tail switch was collected at d-9 and at d0 (TAI) for cumulative cortisol evaluation. A subset of 43 heifers from location 3 had blood samples collected at all handling events and evaluated for cortisol concentrations. Overall, 71% of heifers were classified as calm whereas 29% as excitable. Pregnancy rates to TAI were reduced (P = 0.042) in excitable heifers compared to calm heifers (36% vs. 55%, respectively). Mean concentration of cortisol in the hair was reduced over time (P < 0.001) from d-9 (3.5 ± 0.3 pg/mg) to d0 (1.74 ± 0.3 pg/mg) in all heifers, regardless of temperament. In addition, excitable heifers had increased circulating concentrations of cortisol when compared to calm heifers in all handling events (P = 0.015). More interestingly, despite of temperament, concentrations of circulating cortisol were reduced as the protocol events progressed, with greater cortisol concentrations on d-9, intermediate on d-3, and lesser on d0 (P = 0.031). Therefore, the present study demonstrates that heifer temperament has negative effects in pregnancy rates to TAI programs. However, according to blood cortisol concentrations, no chronic stress response was detected due to cattle handling for the TAI protocol. In fact, blood cortisol concentration was reduced between the initiation and completion of the protocol, indicating that heifers were acclimated to handing. These results support the adoption of acclimation protocols and proper cattle handling as a strategy to increase fertility of heifers that are exposed to TAI.

Cattle stress and pregnancy responses when imposing different restraint methods for conducting fixed time artificial insemination.

Physiological stress responses have been associated with lesser pregnancy rates in beef cattle. Alternative cattle restraint methods have been developed to reduce this negative effect. The objective was to determine if there was a difference in pregnancy rate as a result of fixed-time artificial insemination (FTAI) in Bos taurus females when using a breeding box compared with a squeeze chute for restraining cows when conducting FTAI. There were FTAI treatment regimens imposed on cows and heifers at two separate locations (Virginia Tech University, VT; and R.A. Brown Ranch, RAB) with the FTAI being conducted while animals were restrained in a squeeze chute (n = 169) or a breeding box (n = 162). There was imposing of a 7-day Co-Sync + CIDR pre-breeding treatment regimen. Females were randomly assigned to treatments just prior to breeding. Immediately following breeding, blood was collected using coccygeal venipuncture procedures for assessment of plasma cortisol concentration. Chute and exit scores (1-5) were determined at the time of FTAI. Pregnancy rate, cortisol, chute score, and exit score were analyzed. There was no difference in pregnancy rate between treatments (57 ± 26% and 69 ± 26 %, respectively P = 0.59).There were differences in chute (1.52 ± 0.05 and 1.27 ± 0.05, respectively P < 0.05) and exit (1.26 ± 0.04 and 1.08 ± 0.04, respectively P < 0.05) scores between the two treatment groups. Results from the present study are not conclusive in ascertaining effects of the two types of restraint during FTAI on reproductive efficiency.

Effects of Nerve Growth Factor-ß From Bull Seminal Plasma on Steroidogenesis and Angiogenic Markers of the Bovine Pre-ovulatory Follicle Wall Cell Culture.

Nerve growth factor-ß (NGF) is critical for ovulation in the mammalian ovary and is luteotrophic when administered systemically to camelids and cattle. This study aimed to assess the direct effects of purified bovine NGF on steroidogenesis and angiogenic markers in the bovine pre-ovulatory follicle. Holstein heifers (n = 2) were synchronized with a standard protocol, and heifers with a preovulatory follicle (≥ 12 mm) had the ovary containing the dominant follicle removed via colpotomy. Pre-ovulatory follicles were dissected into 24 pieces containing theca and granulosa cells that were randomly allocated into culture media supplemented with either purified bovine NGF (100 ng/mL) or untreated (control) for 72 h. The supernatant media was harvested for quantification of progesterone, testosterone, and estradiol concentrations, whereas explants were subjected to mRNA analyses to assess expression of steroidogenic and angiogenic markers. Treatment of follicle wall pieces with NGF upregulated gene expression of steroidogenic enzyme HDS17B (P = 0.04) and increased testosterone production (P < 0.01). However, NGF treatment did not alter production of progesterone (P = 0.81) or estradiol (P = 0.14). Consistently, gene expression of steroidogenic enzymes responsible for producing these hormones (STAR, CYP11A1, HSD3B, CYP17A1, CYP19A1) were unaffected by NGF treatment (P ≥ 0.31). Treatment with NGF downregulated gene expression of the angiogenic enzyme FGF2 (P = 0.02) but did not alter PGES (P = 0.63), VEGFA (P = 0.44), and ESR1 (P = 0.77). Collectively, these results demonstrate that NGF from seminal plasma may interact directly on the theca and granulosa cells of the bovine pre-ovulatory follicle to stimulate testosterone production, which may be secondary to theca cell proliferation. Additionally, decreased FGF2 expression in NGF-treated follicle wall cells suggests hastened onset of follicle wall cellular remodeling that occurs during early luteal development.

A retrospective analysis of bull:cow ratio effects on pregnancy rates of beef cows previously enrolled in fixed-time artificial insemination protocols.

This retrospective study aimed to determine if the number of cows exposed per bull affects pregnancy rates of cows returning to estrus after fixed-time artificial insemination (FTAI). Data were compiled over the course of 13 breeding seasons (six fall and seven spring seasons) between 2010 and 2017 from the Virginia Department of Corrections herd. Available records contained data from 17 farms and 324 groups of cows (average 47 cows/group). Multiparous cows and heifers (average age per group: 5.11 ± 0.14 yr; n = 14,868) were exposed to FTAI. After FTAI, animals were placed on pasture with bulls diagnosed as fertile by a breeding soundness exam for natural service of cows who did not become pregnant to FTAI (n = 7,248; average 22 cows/group). Animals were classified as pregnant to FTAI, to natural service on first return to estrus, or to natural service on second or subsequent estrus determined by fetal aging at pregnancy diagnosis. The bull:cow ratio for the total number of cows exposed ranged from 1:9 to 1:73 with an average of 1:31. The bull:cow ratio considering only open cows exposed after FTAI ranged from 1:2 to 1:44 with an average of 1:14. There was significant negative, small correlation between the bull:cow ratio for total number of cows exposed and return to estrus pregnancy rate in fall breeding seasons (P = 0.01, r 2 = 0.04) but not in spring (P = 0.90). There was a significant negative, small correlation between bull:cow ratio of open cows exposed and pregnancy rates to first return to estrus in fall herds with a single sire (P < 0.001, r 2 = 0.11). There was no correlation in fall herds using multiple sires or spring herds (P ≥ 0.12). Bull:cow ratio accounted for only 1-11% of variation in the pregnancy rates, thus we conclude that a decreased bull:cow ratio (up to 1:73) did not affect natural service return to estrus pregnancy rate. Cattlemen may consider a reduced number of bulls needed for natural service breeding after FTAI, which can decrease bull related costs and increase the economic feasibility of adopting FTAI protocols.

Comparison of reproductive performance of AI- and natural service-sired beef females under commercial management.

The objective of this study was to assess differences in reproductive performance of natural service and artificial insemination (AI) sired beef females based on pregnancy outcomes, age at first calving, and calving interval. Data were sourced from 8,938 cows sired by AI bulls and 3,320 cows sired by natural service bulls between 2010 and 2017. All cows were in a commercial Angus herd with 17 management units located throughout Virginia and represented spring and fall calving seasons. All calves were born to dams managed with estrus synchronization. Pregnancy was analyzed with generalized linear mixed models and other reproductive measures with linear mixed models in R. Six models were evaluated with the dependent variables of pregnancy status at the first diagnosis, pregnancy status at the second diagnosis, pregnancy type (AI or natural service) at the first diagnosis, pregnancy type at the second diagnosis, calving interval, and age at first calving. Independent variables differed by model but included sire type of the female (AI or natural service), prebreeding measures of age, weight, and body condition score, postpartum interval, sex of the calf nursing the cow, and management group. No differences were observed between AI- and natural service-sired females based on pregnancy status at first and second pregnancy diagnosis (P > 0.05). Sire type was only found to be significant for age at first calving (P < 0.05) with AI-sired females being 26.6 ± 1.6 d older at their first calving, which was expected because AI-sired females were born early in the calving season making them older at breeding. Surprisingly, age and body condition score were not significant predictors of pregnancy (P > 0.05). Body weight at breeding was not significant for pregnancy (P > 0.05) but was significant for age at first calving (P < 0.05). These data suggested that lighter heifers calved earlier which contradicts our original hypothesis. Overall, commercial Angus females sired by AI or natural service bulls had similar reproductive performance. Factors that were commonly associated with reproductive success were not significant in this commercial Angus herd managed with estrus synchronization. Given the size of these data, the importance of body condition, age, and weight should be reassessed in modern genetics and management practices.

Habituation Protocols Improve Behavioral and Physiological Responses of Beef Cattle Exposed to Students in an Animal Handling Class.

Our objective was to determine the impact of different habituation protocols on beef cattle behavior, physiology, and temperament in response to human handling. Beef heifers were exposed to three habituation strategies: (1) tactile stimulation (brushing) in the working chute for seven consecutive days (STI; n = 18); (2) passage through the working chute for seven consecutive days (CHU; n = 19) and; (3) no habituation (CON; n = 19). Individual heifer respiratory rate (RR; n/min), internal vaginal temperature (VAGT; °C), and blood cortisol were measured. Further, behavior parameters were observed to generate a behavior score, and heifer interaction with students and their behavioral responses were recorded. Habituation with STI and CHU resulted in improved numerical behavioral scores compared to CON, and greater (p ≤ 0.05) handling latencies. Vaginal temperature was decreased in STI compared to CHU and CONT (p ≤ 0.05). Cortisol concentration did not differ among treatments, but decreased (p ≤ 0.05) from the start of the experiment to 14 days after treatment initiation. Both habituation protocols showed benefits, but heifers that received the positive tactile stimulation in the chute had the greatest behavior improvements. Furthermore, these heifers responded more calmly during student-animal interactions in class, which is beneficial for the students' and animals' safety.