Blood Cortisol Concentrations Research Articles

Effect of artificial insemination, ruminal incubation, and esophageal tubing on cortisol concentration in blood of lactating dairy cows

Effect of artificial insemination, ruminal incubation, and esophageal tubing on cortisol concentration in blood of lactating dairy cows

Physiological and metabolic effects of short-term dopamine reduction in healthy horses using a tyrosine hydroxylase inhibitor (alpha-methyl-para-tyrosine)

Alpha-methyl-para-tyrosine (AMPT) is a reversible inhibitor of tyrosine hydroxylase, the rate-limiting enzyme in catecholamine synthesis. This study aimed to determine whether AMPT could reduce dopamine concentrations in horses. Six healthy adult Standardbred geldings were administered AMPT (40 mg/kg BW, orally) or placebo in a randomised crossover study design. Clinical examination findings were recorded, and blood samples were collected for up to 6 h after administration of AMPT or placebo, for measurement of blood glucose, plasma ACTH and cortisol concentrations, and plasma metabolomic analysis. Plasma prolactin concentration was determined as a proxy index of central dopamine reduction. No adverse clinical effects were detected after oral administration of AMPT, with heart rate, mean arterial pressure and blood glucose concentration not differing between AMPT treatment or placebo. Plasma prolactin concentration peaked 1 h after AMPT administration before returning to baseline at 2 h (for five horses) or 6 h (for one horse). Metabolomic analysis demonstrated a reduction in plasma dopamine (0.72-fold change; P=0.016) 1 h after AMPT treatment. Plasma ACTH and cortisol concentrations were not different between AMPT and placebo over time. A few metabolites associated with ketogenesis were increased, and certain amino acids decreased, at 1 h compared with baseline, for both AMPT treatment and placebo. Therefore, AMPT was effective in reducing both central and circulating dopamine concentrations in healthy horses following a single oral dose. Further pharmacokinetic and pharmacodynamic studies are warranted to optimise the dose and duration of AMPT treatment to achieve longer-term dopamine reduction. Plasma metabolomic findings suggested an interruption to energy flux at the time of sample collection, which may be relevant to nutritional studies in horses and warrants further investigation.

When the neighbors are noisy: effect of social challenge in collateral pens of stressed animals.

Regrouping practices are frequent in pig production, altering hierarchy and triggering aggressive behaviors. The present study aimed to investigate the physiological responses of piglets to an experimental model designed to induce stress through systematic social mixing in two trials. In Trial A, a total of 144 crossbred piglets (25 days postweaning) housed in one room within 36 pens (four piglets/pen) were used and randomly assigned to either a control group (piglets maintained in their pen, Ctrl-A) or a social challenge group (piglets mixed, SC-A). In Trial B, the same number of animals (33 days postweaning) and crossbreed line was used, and each piglet was assigned either to a control group (Ctrl-B) or a social challenge group (SC-B) in two independent rooms (rooms Ctrl and SC, 12 pens/ room, six piglets/pen). The social challenge consisted of daily moves of three out of four pen mates and five out of six pen mates, for Trials A and B, respectively. In the Ctrl groups, all piglets stayed in their original pen. Before the 1st mixing day and at the end of the 3rd mixing day, saliva (cortisol concentration) and blood (cortisol concentration changes, hemogram, and immunologic activation) samples were collected from two random piglets per pen. Skin lesion scores of all piglets were also recorded on the front, middle, and rear body regions. In Trial A, the total skin lesions score was higher in the SC-A group compared to the Ctrl-A group after the social challenge (0.53 vs. 0.17; p < 0.05), but an unexpected increase between sampling days in the Ctrl-A piglets (0.06 vs. 0.17; p < 0.05) was also recorded, suggesting that Ctrl-A pigs showed similar aggressivity levels to the SC-A group. Hematological parameters hemoglobin, red blood cell counts, and leukocyte counts present similar changes in both treatment groups after the social challenge. Contrarily, in Trial B, the lesion score only increased in the piglets in room SC (0.08 vs. 0.34; p < 0.05). Results suggest that stable groups may show aggressive behaviors if they are in the same room with socially challenged pigs. Thus, the physical separation of treatment groups in social stress studies is recommended.

PSLBI-23 Effects of peri-castration pain management strategies on feed and water intake, performance, and blood cortisol concentrations of weaned beef steers

Abstract Objectives of this study were to identify if pain management strategies at the time of castration impact feed and water intake, performance, or blood cortisol concentrations in weaned beef steers. Black Angus and Simmental Angus cross bulls [n = 30; average age = 8 ± 1 mo, average body weight (BW) = 272 ± 45.5 kg] were randomly assigned to 1 of 3 treatment groups: 1) Control (CON; n = 10 bulls), castrated via banding; 2) Analgesic (M; n = 10 bulls), received an analgesic (meloxicam; 1 mg/kg BW) immediately after banding; or 3) Anesthetic + analgesic (ML; n = 10 bulls), received an intra-scrotal and intra-cord anesthetic (total lidocaine 15 to 20 mL + 10% sodium bicarbonate) injection immediately prior to banding and an analgesic (meloxicam; 1 mg/kg BW) immediately after banding. Blood collections to measure blood cortisol concentrations were taken on d -7, -0, +0 (day of castration pre- and post-procedure, respectively), 1, and 8. Data were analyzed as repeated measures using the MIXED procedure of SAS with treatment, day, and their interaction as fixed effects and animal as a random effect. While administering analgesics or anesthetics may reduce discomfort, the results of this study showed that these pain management practices do not significantly impact (P ≥ 0.07) on feed (CON = 7.41 ± 0.27 kg; M = 7.72 ± 0.27 kg; ML = 8.06 ± 0.27 kg) and water intake (CON = 20.90 ± 0.69 kg; M = 23.04 ± 0.69 kg; ML = 22.58 ± 0.69 kg), performance (CON = 345.40 ± 12.09 kg; M = 356.97 ± 12.09 kg; ML = 331.93 ± 12.09 kg), or blood cortisol concentrations (CON = 1.01 ± 0.19 ug/Dl; M = 1.19 ± 0.19 ug/Dl; ML = 1.38 ± 0.19 ug/DL). These data indicate that peri-castration pain management strategies can be adopted at the producers’ managerial discretion.

Effects of maternal dietary supplementation with antioxidants on clinical status of mares and their foal

BackgroundThe peripartum period constitutes a delicate physiological moment in mares showing a transient state of oxidative stress. Diet supplementation with antioxidants during pregnancy in women appears to have a beneficial effect on mother and neonate health. The aim of this work was to evaluate the effects of diet supplementation with a commercial product containing a mix of antioxidants (Oxyliver®, Candioli) on the length of gestation, weight, and haemato-biochemical parameters in Italian Salernitano mares and their newborn foals. Eight late-term pregnant mares were randomly divided into two groups: Antiox group receiving 30 g/day of antioxidants, and Car group receiving the same amount of carrot powder, from 290 to 320 days of gestation. The following parameters were evaluated in mares: weight, colostrum composition, haemato-biochemical parameters, progesterone, and cortisol blood concentrations, along with blood oxidant/antioxidant status. Assessments were conducted at specific time points: immediately before the start of diet supplementation (T0), 15 days after (T1), at the end of diet supplementation (T2), within 8 h after parturition (T3), and 10 days post-partum (T4). Foal parameters such as weight, haemato-biochemical values, cortisol concentration, and blood oxidative stress variables were assessed within 8 h of birth (TF0) and at 10 days of age (TF1).ResultsPregnancy was shorter in the Antiox group (P < 0.05) compared with the Car group; the foals’ weight increase of group Antiox (40%) was higher (P < 0.05) compared to those of the Car group (28.6%). The colostrum of the Antiox group exhibited higher levels of Brix, total solids, protein, nonfat solids, casein, urea, density, free fatty acids, and glucose, while lower levels of fat and lactose were observed compared to the Car group (P < 0.05). Mares’ serum albumin at T1 and T3, creatinine, glucose, total proteins, total bilirubin, AST, and ALT at T3 were lower in Antiox than in the Car group. No significant differences were found in foals.ConclusionsWhile the limited sample size and the potential variability of evaluated parameters, the observed outcomes suggest that Oxyliver® supplementation in mares might safely decrease gestation length and enhance liver function, thus potentially improving colostrum quality and offspring development.

Lower hair cortisol concentration in adolescent and young adult patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Q-Fever Fatigue Syndrome compared to controls

BackgroundIn patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS), momentary cortisol concentrations in blood, urine, and saliva are lower compared to healthy controls. Long-term cortisol concentration can be assessed through hair, but it is unclear whether these concentrations are also lower. Additionally, it is unknown if lower cortisol extends to other patients suffering from persistent fatigue and how hair cortisol concentration (HCC) relates to fatigue levels. Therefore, this study examines HCC in fatigued patients with ME/CFS, Q fever Fatigue Syndrome (QFS), Post-COVID-19 condition (PCC), and Juvenile Idiopathic Arthritis (JIA). MethodsAdolescent and young adult patients with ME/CFS (n=12), QFS (n=20), PCC (n=8), JIA (n=19), and controls (n=57) were included. Patients participated in a randomized cross-over trial (RCT) targeting fatigue through lifestyle and dietary self-management strategies. HCC was measured pre-post RCT in patients and once in controls, quantified using a LC-MS/MS-based method. Fatigue severity was measured with the Checklist Individual Strength-8. HCC was compared between groups with ANOVAs. Relations between HCC, fatigue severity, and other variables were investigated using linear regression analyses. ResultsThe ME/CFS (p=.009) and QFS (p=.047) groups had lower HCC compared to controls. Overall, HCC was negatively associated with the presence of symptoms related to chronic fatigue syndromes (e.g., sleeping issues, often feeling tired, trouble thinking clearly; β=-0.018, p=.035), except in the QFS group (β=.063, p<.001). Baseline HCC did not predict fatigue improvement during the RCT (p=.449), and HCC increased during the trial (Mdif=.076, p=.021) regardless of clinically relevant fatigue improvement (p=.658). ConclusionLower cortisol concentration can also be observed in the long-term. Lower HCC is not limited to ME/CFS, as it was also observed in QFS. The role of cortisol may differ between these diagnoses and appears to be unrelated to fatigue levels.

Fecal Microbiota Transplantation for Sleep Disturbance in Post-acute COVID-19 Syndrome

Background & AimsPost-acute COVID-19 syndrome (PACS) is associated with sleep disturbance but treatment options are limited. The aetiology of PACS may be secondary to alterations in the gut microbiome. Here, we report the efficacy of faecal microbiota transplantation (FMT) in alleviating post-COVID insomnia symptoms in a non-randomised, open-label prospective interventional study. MethodsBetween September 22, 2022 and May 22, 2023, we recruited 60 PACS patients with insomnia defined as Insomnia Severity Index (ISI) ≥ 8 and assigned them to the FMT group (FMT at weeks 0, 2, 4 and 8; n=30) or the control group (n=30). The primary outcome was clinical remission defined by an ISI of less than eight at 12 weeks. Secondary outcomes included changes in the Pittsburgh Sleep Quality Index (PSQI), Generalised Anxiety Disorder-7 scale (GAD-7), Epworth Sleepiness Scale (ESS), Multidimensional Fatigue Inventory (MFI), blood cortisol and melatonin, and gut microbiome analysis on metagenomic sequencing. ResultsAt week 12, more patients in the FMT than the control group had insomnia remission (37.9% vs 10.0%; p=0.018). The FMT group showed a decrease in ISI score (p<0.0001), PSQI (p<0.0001), GAD-7 (p=0.0019), ESS (p=0.0057) and blood cortisol concentration (p=0.035) from baseline to week 12, but there was no significant change in the control group. There was enrichment of bacteria such as Gemmiger formicilis and depletion of microbial pathways producing menaquinol derivatives after FMT. Gut microbiome profile resembled that of the donor in FMT responders but not in non-responders at week 12. There was no serious adverse event. ConclusionThis pilot study showed that FMT could be effective and safe in alleviating post-COVID insomnia and further clinical trials are warranted. ClinicalTrials.gov identifier: NCT05556733.

Stress response to social isolation followed by exposure to a novel object in aged ewes born to undernourished mothers

Fetal programming by subnutrition affects offspring’s behaviour, metabolism, and sensitivity to stressors in sheep. The objective was to determine the stress response of ewes born to mothers nutritionally restricted during gestation to social isolation followed by exposure to a novel object. Twenty-six-year-old Corriedale ewes born to mothers who grazed high or low pasture allowances (HPA and LPA groups) from 23 days before conception until 122 days of gestation were used. Ewes were individually isolated in a novel place for 10 min, and 5 min after its beginning, an orange ball was dropped into the test pen. The ewes’ behaviours were recorded during the test. Blood proteins, glucose and cortisol concentrations, heart and respiratory rates and rectal and surface temperatures were determined. The number of times looking at the ball tended to be greater in HPA ewes than LPA (6.7 ± 1.0 vs 4.7 ± 0.8, P = 0.08). The LPA ewes had greater serum albumin concentration than HPA ewes (3.2 ± 0.1 g/dL vs 3.0 ± 0.1 g/dL, P = 0.02), regardless of the applied stressors. Overall, the nutritional treatments applied to ewes during their intrauterine development did not modify the stress responses to social isolation followed by exposure to a novel object.

48 Use of 4,500 FTU/kg of phytase on performance and blood parameters of finishing pigs

Abstract Phytase hyper-dosing is a recent concept in nutrition based on the use of high doses of the enzyme with growth promoting effect. Supplementary release of inosotol, rapid and strong destruction of phytic acid and other non-phosphoric effects are proposed mechanisms for the positive results found on pig growth. The hypothesis of this concept would be to accelerate this destruction of the phytate improving feed conversion ratio (FCR). A second hypothesis is that this increased destruction of the phytate may generate decreased concentrations of cortisol, because the inositol has insulin-like effects, reducing glycemy and reducing cortisol concentrations and FCR. To evaluate these hypotheses, two different studies were conducted, in Brazil and Mexico, using Quantum Blue (AB Vista) in two formulation strategies, Control Group - a dose and nutritional matrix of 750 FTU/kg; Hyper-dosing Group - a dose strategy of 4,500 FTU/kg (but with the same matrix of 750 FTU/kg). In the Brazilian evaluation (Trial 1 - RESTRICTED feed consumption trial), 364 animals/treatment were used, divided into 26 replications of 14 animals each (13 pens of males and 13 pens of females). In the Mexican evaluation (Trial 2 – NO restricted feed consumption trial), 400 animals/treatment were used, divided into 8 replications of 50 animals each, all animals used in this evaluation were males. In both studies, body weight gain, feed intake and FCR were evaluated. In the Brazilian study, in addition, the blood cortisol concentration of the animals was also evaluated. The data from each experiment were analyzed using the GLM platform (Minitab 18), and ANOVA used to assess differences on treatments (P ≤ 0.05). As presented in Table 1, in Trial 1, no differences were noted (P &amp;gt; 0,05) with the Hyper-dosing strategy for males; however, for females, this strategy improved (P ≤ 0.05) the FCR in Hyper-dosing Group versus Control Group. This difference in results between sexes can be explained by the feeding rate adopted in this experiment, which was similar for all animals (highly restrictive), what may have penalized some animals more because of the greater maintenance costs. The analysis of the blood parameters of these animals demonstrated a reduction (P ≤ 0.05) in cortisol concentrations, indicating that the use of phytase Hyper-dosing can be even better in situations of thermal or environmental stress. Also presented in Table 1, in the Mexican study the results were possible to observe a statistical trend (P ≤ 0.05 and &amp;gt; 0.10) for the use of the Hyper-dosing concept for FCR. In conclusion, the use of 4,500 FTU/kg of Quantum Blue in the last 30 d of finishing pigs helps to improve performance and reduce blood cortisol concentrations of these animals, especially in situations where the production efficiency rate is moderate.

Synergistic Effect of Dietary Supplementation with Sodium Butyrate, β-Glucan and Vitamins on Growth Performance, Cortisol Level, Intestinal Microbiome and Expression of Immune-Related Genes in Juvenile African Catfish (Clarias gariepinus).

The effect of dietary supplementation with sodium butyrate, β-glucan and vitamins (A, D3, E, K, C) on breeding indicators and immune parameters of juvenile African catfish was examined. The fish were fed with unenriched (group C) and enriched feed with a variable proportion of sodium butyrate/β-glucan, and constant content of vitamins (W1-W3). After the experiment, blood and the middle gut were collected. The microbiome of the gut was determined using Next Generation Sequencing (NGS). Liver tissue was collected for determination of expression of immune-related genes (HSP70, IL-1β, TNFα). W2 and W3 were characterized by the most favorable values of breeding indicators (p < 0.05). The highest blood cortisol concentration was in group C (71.25 ± 10.45 ng/mL), and significantly the lowest in W1 (46.03 ± 7.01 ng/ mL) (p < 0.05). The dominance of Cetobacterium was observed in all study groups, with the largest share in W3 (65.25%) and W1 (61.44%). Gene expression showed an increased number of HSP70 genes in W1. IL-1β and TNFα genes peaked at W3. The W3 variant turns out to be the most beneficial supplementation, due to the improvement of breeding and immunological parameters. The data obtained can be used to create a preparation for commercial use in the breeding of this species.

Alterations of whole body glucose metabolism in a feline SARS-CoV-2 infection model.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been especially devastating to patients with comorbidities, including metabolic and cardiovascular diseases. Elevated blood glucose during SARS-CoV-2 infection increased mortality of patients with COVID-19, although the mechanisms are not well understood. It has been previously demonstrated that glucose transport and utilization is a crucial pathway for other highly infectious RNA viruses. Thus, we hypothesized that SARS-CoV-2 infection could lead to alterations in cellular and whole body glucose metabolism. Specific pathogen-free domestic cats were intratracheally inoculated with USA-WA1/2020 (wild-type) SARS-CoV-2 or vehicle-inoculated, then euthanized at 4- and 8-days postinoculation (dpi). Blood glucose and cortisol concentrations were elevated at 4 and 8 dpi. Blood ketones, insulin, and angiotensin II concentrations remained unchanged throughout the experimental timeline. SARS-CoV-2 RNA was detected in the lung and heart, without changes in angiotensin-converting enzyme 2 (ACE2) RNA expression. In the lung, SARS-CoV-2 infection increased glucose transporter 1 (GLUT1) protein levels at 4 and 8 dpi, whereas GLUT4 level was only upregulated at 8 dpi. In the heart, GLUT-1 and -4 protein levels remained unchanged. Furthermore, GLUT1 level was upregulated in the skeletal muscle at 8 dpi, and AMPK was activated in the hearts of infected cats. SARS-CoV-2 infection increased blood glucose concentration and pulmonary GLUT protein levels. These findings suggest that SARS-CoV-2 infection induces metabolic reprogramming primarily in the lung to support viral replication. Furthermore, this translational feline model mimicked human COVID-19 and could be used to explore novel therapeutic targets to treat metabolic disease during SARS-CoV-2 infection.NEW & NOTEWORTHY Our study on a feline model of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, mirroring human COVID-19, revealed alterations in whole body and cellular glucose metabolism. Infected cats developed mild hyperglycemia, increased protein levels of glucose transporters in the lung, and AMPK activation in the heart. These findings suggest that SARS-CoV-2 infection induces metabolic reprogramming in the cardiorespiratory system to support viral replication. Understanding these mechanisms could lead to novel antiviral therapeutic strategies.

Cortisol as a cerebral cortex neurons apoptosis regulator in acute phase of ischemic stroke (clinical and pathological study)

In response to ischemic stroke (IS) a natural activation of the stress-realizing system occurs. The features of this activation influence the outcome of the acute period and the prognosis of recovery and can be adjusted. At the same time, the role of the stress-realizing system in the pathogenesis of IS is still unexplored.Objective: to investigate the effect of peripheral blood cortisol concentration on the regulation of apoptosis of neurons of the cerebral cortex in the acute phase of IS.Material and methods. A prospective clinical and pathological study was performed. It included 9 patients with IS in the left middle cerebral artery territory who were admitted to hospital and died in the hyperacute phase of IS and had no infectious complications, allergic reactions or oncological diseases and who did not undergo thrombolysis. The cerebral cortex was examined. Neuron-specific enolase (NSE), protein 53 (p53), caspase 3, caspase 8, Fas receptor (CD95), and Fas apoptotic inhibitory molecule 2 (FAIM2) were determined on the slices using an indirect immunoperoxidase immunohistochemical staining method. A total of 567 microscopic fields were analysed for the group of patients with IS and 63 fields for the control group (three people). Before death, the blood concentrations of sFas, sFasL, cortisol, adrenocorticotropic hormone, adrenaline and norepinephrine were determined by enzyme immunoassay (the control group consisted of 28 people).Results. Significant correlation was found between the proportion of casp3-positive neurons and the concentration of cortisol in peripheral blood in zones 2 (r=0.263; p&lt;0.01) and 3 (r=0.383; p&lt;0.01). In the 2nd zone, significant negative correlation was found with the concentrations of sFas (r=-0.177; p&lt;0.05) and sFasL (r=-0.164; p&lt;0.05); in the 3rd zone, significant positive correlation was found with the ratio of the concentrations of sFasL and sFas (r=0.240; p&lt;0.01). The proportion of Fas-positive neurons in the cerebral cortex correlated significantly with the concentration of the soluble form of this molecule (for the 1st zone – r=0.222, for the 2nd zone – r=0.438, for the 3rd zone – r=0.289; p&lt;0.01) and the ratio of the concentrations of sFasL and sFas (respectively: r=0.231, r=0.266 and r=0.281; p&lt;0.01) in the peripheral blood.Conclusion. Peripheral blood cortisol concentration is a factor that determines the regulation of apoptosis of neurons in the cerebral cortex in the acute phase of IS.

Effects of weaning age and pace on blood metabolites, cortisol concentration, and mRNA abundance of inflammation-related genes in gastrointestinal, adipose, and liver tissue of Holstein dairy calves

The objective of this study was to evaluate the effects of weaning age and pace on blood metabolites, cortisol concentration, and mRNA abundance of inflammation-related genes in Holstein dairy calves. A total of 70 1-d-old calves (38.8 ± 4.4 kg BW ± SD), blocked by sex and birth BW, were randomly assigned to a 2 × 2 factorial arrangement of treatments. The first factor was weaning age, which was either early (6 wk) or late (8 wk). The second factor was weaning pace, which was either abrupt (4 steps down over 3 d; the initial milk replacer was 7.6 L, which was reduced by 1.9 L in each step-down) or gradual (7 steps down over 14 d; the initial milk replacer was 7.6 L, which was reduced by 1.09 L in each step-down), generating early-abrupt (EA), early-gradual (EG), late-abrupt (LA), and late-gradual (LG) treatments. All treatments had 10 female and 8 male calves, except EA that had 1 fewer male calf. Milk replacer (24% CP, 17% fat) was bottle fed, up to 1,200 g/d, twice daily (0600 h and 1800 h). The EA and EG treatment calves received 46.2 kg of milk replacer, and the LA and LG treatment calves received 63 kg of milk replacer. The study had 2 cohorts (2020, n = 40; 2021, n = 31), and each cohort included all treatments. Blood was collected from the jugular vein at 0900 h at 3 and 7 d of age, and a day before starting and a day after weaning completion. Male calves were humanely killed a day after weaning. Rumen, jejunum, large intestine, liver, omental adipose and perirenal adipose tissues were sampled to determine the mRNA abundance of inflammation-related genes. Weaning pace, age, pace × age, birth BW, and sex were included as fixed and cohort was included as random effects in the model. Blood metabolites and cortisol were analyzed as repeated measures, and sampling day, pace × sampling day, and age × sampling day were also included as additional fixed effects. Significance was noted at P ≤ 0.05 and tendencies when 0.05 <P ≤ 0.10. The EA calves showed a tendency to have the greatest nonesterified fatty acid (NEFA) concentration compared with all other treatments. We observed a pace × day effect on serum NEFA and BHB; calves weaned at an abrupt pace had an increased level of NEFA after weaning compared with those weaned gradually. Calves weaned at the gradual pace showed the greatest serum BHB after weaning. Most mRNA abundances for inflammation-related genes affected by treatments showed a similar pattern. They were downregulated by the abrupt (liver IL-1β) and early weaning (jejunum TNF-α and ICAM), and in some cases, the interaction intensified the effect, demonstrating a weakened immune response in calves experiencing more stressful conditions (EA: IL-6 in the liver and NF-κB in the perirenal adipose tissue). Overall, the downregulation of the mRNA abundance of inflammation-related genes in EA calves may be attributed to the suppression of the immune system and an immature immune response. Furthermore, the greater NEFA in EA calves could be attributed to a reduced starter intake, less developed rumen, or shorter time during the weaning transition.

Blood cortisol concentration in response to recurrent manipulation in crossbred Holstein embryo donors

Se determinó la respuesta neuro–endócrina de la donadora al reducir el número de aplicaciones de hormona folículo–estimulante (FSH) como factor de superovulación. Ocho vacas Holstein mestizas fueron distribuidas aleatoriamente en dos tratamientos (T): T1 (n=4) recibieron una dosis de 200 mg de FSH vía epidural (EP) en el día 4 del protocolo de superovulación (SOV), en T2 se administró 300 mg de FSH repartidas en 8 dosis decrecientes vía intramuscular (IM), los días 4; 5; 6 y 7 del protocolo en la mañana y tarde. La concentración de cortisol se determinó a las 0; 2; 4; 6 ,24; 26; 28; 30; 48; 50; 52; 64; 72; 74; 76 y 78 horas (h) del día 4. La frecuencia cardiaca (FC), respiratoria (FR) y los niveles de glucosa fueron evaluados el día 4 a las 05h45; 06h05; 08h00; 10h00; 12h00; 17h45 y 18h05. El cortisol a las 0h fue similar en los dos T: T1 (10,9 ± 0,24 µg·dL-1) y T2 (10,8 ± 0,33 µg·dL-1) y alcanzó su mayor nivel a las 4h en T1 (15,8 ± 1,39 µg·dL-1) y en T2 (16,4 ± 0,28 µg·dL-1) sin diferencia entre T (P&gt;0,05). En las siguientes valoraciones, el cortisol disminuyó a niveles basales en los dos T. La FC a las 05h45, mostró valores similares en T1 (65,3 ± 1,65 pul·min-1) y en T2 (66,3 ± 1,43 pul·min-1); sin embargo, a las 06h05 FC se incrementó en T1 (74,3 ± 1,54 pul·min-1) y en T2 (84,2 ± 1,73 pul·min-1) y disminuyó a partir de las 08h00. Igual comportamiento fue observado con la FR y la glucosa. Se concluye que llevar a la donadora a la manga de sujeción para administrar FSH, constituye un factor estresante que incrementa la FC, FR, cortisol y glucosa, factores que influyen sobre el porcentaje de ovulaciones en los dos T.

Influence of Training Load on the Level of Steroid Hormones in Mixed Martial Arts Athletes (on the Example of Horting)

The Purpose of the Research is to study the nature of changes in the concentration of cortisol and testosterone in the horting athletes’ during the use of different structured strength training load models. The Methods of the Research. 60 athletes took part in the study that have been divided into 3 research groups. Representatives of the examined groups used experimental strength training load models. Based on the results of laboratory control, the characteristics of changes in the concentration of cortisol and testosterone hormones in the blood serum of athletes during the research were determined. The Research Results. It was found that only the athletes of the 3rd group had an increasing of cortisol concentration in their blood by 3,5 % in response to the strength training load. A comparative analysis of the results at the beginning and at the end of the studies revealed that basal level of cortisol concentration in blood of the 1st and the 2nd groups of athletes decreased by 9,4 % (p&lt;0,05), despite the fact that the representatives of these groups used completely different training load regimes, sets of exercises and types of motor activity energy supply. However, the basal cortisol level of the 3rd group athletes, increased by 17,5 % (p&lt;0,05) in contrast to the initial data at rest. The results of operative control indicate a decrease the testosterone concentration in the 2nd group athletes` blood after training by 7,3 % (p&lt;0,05). A comparative analysis of laboratory control results of the initial and finished studies indicates that the basal level of the hormone testosterone concentration in the 1st group athletes` blood increased by 17,9 % (p&lt;0,05) compared to the initial data. The basal level of the studied steroid hormone of the 2nd and the 3rd groups of athletes after 3 months is being without any changes. Findings. It was determined that during the strength training load in horting, the use of a training model with alternating variations of different load intensities in compliance with the principle of “premature fatigue” due to the preliminary trainings of an isolating nature for a certain muscle group, and then of a basic nature with indicators of working weight burden of 70,0 % of 1RM, facilitates increasing of the cortisol and testosterone concentration in the blood in response to a stressful stimulus.

Preslaughter feed withdrawal time and its effect on rabbit blood measures, gastrointestinal tract parameters and Longissimus lumborum glycolytic potential

This study aimed to characterise the physiological response of rabbits to feed withdrawal without stress caused by crating and transport to the slaughterhouse. A total of 72 recently weaned Grimaud rabbits were allocated into 12 cages, each with 6 rabbits (3 females and 3 males, to reflect commercial practices). A preslaughter feed withdrawal time (FWT) was randomly assigned to each of the 12 cages (t=0, 3, 6, 8, 10, 12, 14, 16, 18, 20, 22 or 24 h). Blood lactate and cortisol concentrations were measured at exsanguination. These observations did not indicate an elevated level of stress in the rabbits (P&gt;0.05). The maximum Longissimus lumborum glycolytic potential was observed for rabbits that fasted for 3 and 6 h and was relatively stable from 127.78 to 139.04 μmol/g for rabbits with FWT longer than 12 h. As expected, gastrointestinal tract and stomach content weights were lower for rabbits with longer FWT (P&lt;0.0001), while caecum weights did not (P=0.051). Rabbits with longer FWT had lower stomach pH and higher caecum pH (both P&lt;0.0001). Metataxonomic 16S analysis revealed that FWT had a significant effect (all P&lt;0.01) on microbiome beta diversity in faeces and caecum. The polymerase chain reaction analysis using specific primers revealed Enterobacteriaceae presence in the faeces of male rabbits only at 18 and 22 h. Our results suggest that the caecotrophic behaviour of rabbits allows them to be particularly resistant to hunger despite their small size. However, to limit Enterobacteriaceae shedding, the FWT should not exceed 18 h.

166 Pre-Weaned Calves Have Increased Cortisol Concentrations Post-Wildfire Smoke Exposure

Abstract The western states of the U.S., home to some of the largest cattle operations in the country, are increasingly experiencing losses related to wildfire events. Wildfires are predicted to intensify with climate change; rising temperatures, droughts, and drier climatic conditions. Although wildfires do not directly endanger most humans and animals, the resultant smoke can disperse great distances and increase disease susceptibility and death in populations removed from its origin. There is a lack of literature on how wildfire smoke exposure can affect livestock physiology, health, and productivity. Therefore, this study aimed to evaluate changes in blood markers of cattle naturally exposed to wildfire smoke. Eighteen beef-on-dairy calves (Jersey X Simmental) from a commercial farm were enrolled in this study at birth (May to June 2022). Blood samples for analysis of cortisol, acute phase proteins, and pro- and anti-inflammatory cytokines were collected before (June to August), during (September), and after smoke exposure (September and October), in a total of seven collections. Additionally, rectal temperature and health scores were collected from each calf at those time points. Air quality (AQ) data, specifically particulate matter (PM2.5; EPA standard for AQ; 35 µg/m3) near the study location (Vale, OR), was obtained from the AirNow database. For statistical analysis, calf was considered the experimental unit, and all data were analyzed using the MIXED procedure of SAS (SAS Inst. Inc., Cary, NC). Air quality before smoke exposure was considered adequate, and PM 2.5 was, on average, 4.9 µg/m3 from June to August. In September, a wildfire reduced AQ at the study location, increasing PM 2.5 to an average of 44.6 µg/m3 for four consecutive days. After the fire was contained, AQ improved, and PM2.5 dropped to 8.6 ug/m3. Blood cortisol concentrations changed over time (P &amp;lt; 0.001). Cortisol concentrations of samples collected before smoke exposure did not differ (P = 0.89) at 4.4, 2.0, and 1.9 ng/mL (SEM:1.3). Cortisol concentrations increased (P &amp;lt; 0.001) and peaked during smoke exposure, at 10.3 and 7.0 ng/mL (SEM:1.4). Immediately after smoke exposure, cortisol concentrations averaged 6.3 ng/mL, intermediate between those before and during smoke exposure (P = 0.89; SEM:1.3). Interestingly, in the last post-smoke exposure sample, cortisol concentration averaged 9.5 ng/mL, similar to concentrations during smoke exposure (P = 0.99; SEM:1.3). This increase in cortisol concentration post-smoke exposure was unexpected but likely explained by the calves having been weaned two days before this final sampling. In summary, calves naturally exposed to wildfire smoke had increased blood cortisol concentrations with concentrations similar to those observed shortly after post-weaning, a practice known to be challenging and stressful for calves.

291 Effect of Early vs. Late Maturing Sire Lines and Creep Feeding on the Stress Response, Intestinal Permeability, and Growth Performance of Nursery and Finishing Pigs

Abstract A total of 21 litters (early or late maturing Duroc × DNA 241) resulting in 247 pigs were used in a 170-day trial to determine the effect of sire lines selected for either early or late maturing growth rates and creep feeding on the stress response, intestinal permeability, and growth performance of nursery and finishing pigs. Treatments were arranged in a 2 x 2 factorial with main effect of Duroc sire line (early or late maturing) and creep feeding (with or without starting 14 d before weaning). In the nursery, there were 4 or 5 pigs per pen and 12 or 13 replications per treatment. Thirty minutes after weaning (initially 6.4 kg BW), 7 gilts per treatment were used to determine cortisol concentrations in response to weaning. Blood cortisol concentrations were increased (P &amp;lt; 0.01; 104.0 v. 83.5 ng/mL) in late maturing pigs compared with early maturing pigs. After almost no feed consumption by either group on d 1, late maturing pigs had decreased daily feed intake (P &amp;lt; 0.001) than early maturing pigs from days 2 to 14 post-weaning. Likewise, a greater percentage (P &amp;lt; 0.001) of late maturing pigs had BW less than their weaning weights on d 3 post-weaning compared with early maturing pigs (Table). Thus, late maturing pigs had decreased (P &amp;lt; 0.001) ADG and ADFI during the first 3 days in the nursery. Creep feeding had no effect on initial performance. No differences were observed in intestinal permeability between treatments. For overall nursery performance, a significant interaction was observed for ADG (P = 0.007) and ADFI (P &amp;lt; 0.001), with creep feeding providing a benefit in late maturing pigs, but not in early maturing pigs. Early maturing pigs had poorer G:F (P &amp;lt; 0.001) than late maturing pigs. At the end of the nursery, 241 pigs were transported to the finisher and randomly placed in pens based on treatment. There were 7 or 8 pigs per pen and 7 or 8 replications per treatment. For overall finishing performance, an interaction was observed for ADG (P = 0.037), with late maturing pigs that received creep feed having increased ADG compared with the other treatments. An interaction was also observed for ADFI (P = 0.007), with late maturing pigs that did not receive creep feed having decreased ADFI compared with late maturing pigs that received creep feed or early maturing pigs whether they received creep feed or not. In summary, early maturing pigs had lower stress response at weaning and improved ADG and ADFI until approximately 100 kg, at which point late maturing pigs began to exhibit greater ADG. Late maturing pigs had improved feed efficiency throughout the experiment. Creep feeding late maturing pigs resulted in improved growth performance compared with providing no creep feed, whereas creep feed did not impact early maturing pigs.

Auction market placement and a rest stop during transportation affect the respiratory bacterial microbiota of beef cattle.

Bovine respiratory disease (BRD) is a significant health problem in beef cattle production, resulting in considerable economic losses due to mortalities, cost of treatment, and reduced feed efficiency. The onset of BRD is multifactorial, with numerous stressors being implicated, including transportation from farms to feedlots. In relation to animal welfare, regulations or practices may require mandatory rest times during transportation. Despite this, there is limited information on how transportation and rest stops affect the respiratory microbiota. This study evaluated the effect of cattle source (ranch-direct or auction market-derived) and rest stop duration (0 or 8 h of rest) on the upper respiratory tract microbiota and its relationship to stress response indicators (blood cortisol and haptoglobin) of recently weaned cattle transported for 36 h. The community structure of bacteria was altered by feedlot placement. When cattle were off-loaded for a rest, several key bacterial genera associated with BRD (Mannheimia, Histophilus, Pasteurella) were increased for most sampling times after feedlot placement for the ranch-direct cattle group, compared to animals given no rest stop. Similarly, more sampling time points had elevated levels of BRD-associated genera when auction market cattle were compared to ranch-direct. When evaluated across time and treatments several genera including Mannheimia, Moraxella, Streptococcus and Corynebacterium were positively correlated with blood cortisol concentrations. This is the first study to assess the effect of rest during transportation and cattle source on the respiratory microbiota in weaned beef calves. The results suggest that rest stops and auction market placement may be risk factors for BRD, based solely on increased abundance of BRD-associated genera in the upper respiratory tract. However, it was not possible to link these microbiota to disease outcome, due to low incidence of BRD in the study populations. Larger scale studies are needed to further define how transportation variables impact cattle health.

Effects of dietary chromium supplementation on blood biochemical parameters in dairy cows: A multilevel meta-analytical approach

Chromium (Cr) has been reported to modulate blood biochemistry in dairy cows. However, there is a discrepancy in the literature regarding the effects of dietary Cr supplementation on various blood parameters. This meta-analysis aimed to evaluate the effects of Cr supplementation in dairy cows on blood glucose, insulin, glucagon, nonesterified fatty acid (NEFA), cortisol, and serum total protein (STP) concentrations. Following relevant literature data extraction, a 3-level meta-analytical random effect model was fitted to the data expressed as standardized mean difference (SMD) of outcome measures of control versus Cr-supplemented cows (i.e., difference in mean between control and treatment group or pooled standard deviation). The SMD can be categorized as having a small effect (0.20), a moderate effect (0.50), and a large effect (0.80). The meta-regression identified the potential sources of heterogeneity, including the body weight of cows, experimental duration/duration of Cr supplementation, blood sampling time (3 wk before parturition until 4 wk after parturition categorized as the transition period, else as the nontransition period), and form of Cr complexes. Blood glucose did not differ significantly between control and Cr-supplemented cows with an estimated SMD of μ = 0.0071 (95% confidence interval [CI]: -0.212 to 0.226). The effect of Cr supplementation on blood insulin was also nonsignificant with an SMD of μ = 0.0007 (95% CI: -0.191 to 0.193). Cows receiving Cr supplements had significantly higher levels of glucagon than controls (95% CI: 0.116 to 0.489), with an estimated SMD = 0.303. Combined transition and nontransition data suggest Cr supplementation did not affect the concentration of NEFA. However, in transition cows, Cr supplementation significantly decreased blood NEFA levels as compared with controls (95% CI: -0.522 to -0.0039), with estimated SMD = -0.263. The estimated SMD was μ = -0.1983 (95% CI: -0.734 to 0.337) for cortisol and -0.0923 (95% CI: -0.316 to 0.131) for total protein. In summary, Cr supplementation in the transition cows decreased NEFA concentration. Blood glucose, insulin, cortisol, and STP concentrations were unaffected. However, Cr supplementation increased glucagon concentration.