Transportation stress alters the circulating steroid environment and neutrophil gene expression in beef bulls

Finding biomarkers of experience in animals

At a time when there is a growing public interest in animal welfare, it is critical to have objective means to assess the way that an animal experiences a situation. Objectivity is critical to ensure appropriate animal welfare outcomes. Existing behavioural, physiological, and neurobiological indicators that are used to assess animal welfare can verify the absence of extremely negative outcomes. But welfare is more than an absence of negative outcomes and an appropriate indicator should reflect the full spectrum of experience of an animal, from negative to positive. In this review, we draw from the knowledge of human biomedical science to propose a list of candidate biological markers (biomarkers) that should reflect the experiential state of non-human animals. The proposed biomarkers can be classified on their main function as endocrine, oxidative stress, non-coding molecular, and thermobiological markers. We also discuss practical challenges that must be addressed before any of these biomarkers can become useful to assess the experience of an animal in real-life.

Current Knowledge on the Transportation by Road of Cattle, including Unweaned Calves

Transport conditions have the potential to alter the physiological responses of animals to the psychological or physical stress of transport. Transportation may introduce multiple physical and psychological stressors to unweaned calves and adult cattle, including noise, overcrowding, food and water deprivation, extreme temperatures, commingling with unfamiliar animals, handling by unfamiliar humans, and being placed in a novel environment upon arrival. Apart from these factors, the type of road and even driving skill may affect the welfare of animals. One of the concerns regarding cattle transport is that the handling and marketing of animals prior to a journey may lengthen the period of feed withdrawal. Furthermore, feed withdrawal can impact animal welfare through hunger and metabolic stress. Transportation is also associated with a decrease in animal performance as well as an increase in the incidence of bovine respiratory disease. It is well established that the transportation of cattle is a stressor that causes a quantifiable response; however, excessive stress during transport resulting in physiological or pathological changes can be reduced with best management practices. The objective of this review was to analyse the available scientific literature pertaining to the transport by road of cattle, including unweaned calves.

Assessment of thermal changes in water buffalo mobilized from the paddock and transported by short journeys

Evaluating the welfare of buffaloes during transport is key to obtaining and commercializing high-quality meat products; however, effective assessments require recognizing several stressors that activate physiological mechanisms that can have repercussions on the health and productive performance of species. The aim of this study was to evaluate the surface temperatures of different body and head regions in this species during events prior, and posterior, to transport for short periods; that is, from paddock to loading. The second goal was to determine the level of correlation between thermal windows. This study used infrared thermography (IRT) to evaluate the surface temperature of 624 water buffaloes (Buffalypso breed) during 12 short trips (average duration = 2 h ± 20 min) by focusing on 11 regions of the body (Regio corporis), in the head regions (Regiones capitis) the face regions (Regiones faciei), Orbital region (Regio orbitalis) with special attention to structures such as the lacrimal caruncle, periocular area and lower eyelid (Regio palpebralis inferior); nasal region (Regio nasalis) with special attention to nostril thermal window; and regions of the skull (Regiones cranii) such as auricular region (Regio auricularis) with special attention to auditory canal and frontal-parietal region (Regio frontalis-parietalis) and trunk region (Truncus regionis) such as thoracic and abdominal regions, regions of the vertebral column (Columna vertebralis) with the thoracic vertebral region (Regio vertebralis thoracis) and lumbar region (Regio lumbalis); and regions of the pelvis limb (Regiones membri pelvini). Recordings were made during seven phases: paddock (P1), herding (P2), corral (P3), chute handling (P4), shipping (P5), pre- (P6), and post-transport (P7). A total of 48,048 readings were obtained from 11 thermal windows. The results showed that the surface temperatures of the windows increased by as much as 5°C during P2, P3, P5, P6, and P7 compared to P1 and P4 (p < 0.0001). Differences of at least 1°C were also observed between thermal windows in the craniofacial, lateral corporal, and peripheral zones (p < 0.0001). Finally, a strong positive correlation (r = 0.9, p < 0.0001) was found between the thermal windows. These findings lead to the conclusion that the surface temperature of the craniofacial and corporal regions of buffaloes transported for short periods varied in relation to the phase of mobilization (from paddock to post-transport), likely as a response to stressful factors, since herding and loading increased the thermal values in each window. The second conclusion is that there are strong positive correlations between central and peripheral thermal windows.

Welfare of cattle during transport

In the framework of its Farm to Fork Strategy, the Commission is undertaking a comprehensive evaluation of the animal welfare legislation. The present Opinion deals with protection of cattle (including calves) during transport. Welfare of cattle during transport by road is the main focus, but other means of transport are also covered. Current practices related to transport of cattle during the different stages (preparation, loading/unloading, transit and journey breaks) are described. Overall, 11 welfare consequences were identified as being highly relevant for the welfare of cattle during transport based on severity, duration and frequency of occurrence: group stress, handling stress, heat stress, injuries, motion stress, prolonged hunger, prolonged thirst, respiratory disorders, restriction of movement, resting problems and sensory overstimulation. These welfare consequences and their animal-based measures are described. A variety of hazards, mainly relating to inexperienced/untrained handlers, inappropriate handling, structural deficiencies of vehicles and facilities, poor driving conditions, unfavourable microclimatic and environmental conditions, and poor husbandry practices leading to these welfare consequences were identified. The Opinion contains general and specific conclusions relating to the different stages of transport for cattle. Recommendations to prevent hazards and to correct or mitigate welfare consequences have been developed. Recommendations were also developed to define quantitative thresholds for microclimatic conditions within the means of transport and spatial thresholds (minimum space allowance). The development of welfare consequences over time was assessed in relation to maximum journey duration. The Opinion covers specific animal transport scenarios identified by the European Commission relating to transport of unweaned calves, cull cows, the export of cattle by livestock vessels, the export of cattle by road, roll-on-roll-off ferries and 'special health status animals', and lists welfare concerns associated with these.

Effects of postweaning supplementation of immunomodulatory feed ingredient on circulating cytokines and microbial populations in programmed fed beef heifers

The objective was to determine the effects of an immunomodulatory feed ingredient following weaning on cytokine expression and fecal microbial populations of heifers. Commercial Angus heifers (n = 72) were weaned (227 ± 7 d of age), blocked by BW (n = 9 blocks), and randomly assigned to one of two pens per block. Pens within weight block (four heifers per pen) were then randomly assigned to treatments. Heifers were fed twice daily from days 0 to 60 (to gain 0.75 kg/d) and top dressed with either 18 g/heifer/d of the immunomodulatory feed ingredient (Celmanax; Arm and Hammer Animal Nutrition, Princeton, NJ; CEL) or corn-germ meal (CON). Blood samples were collected on days 0, 15, 30, 45, 60 and fecal grab samples on day 0 of the feeding trial. After day 60, two heifers per pen (n = 32) were randomly selected for a transportation challenge. Serum samples were collected at hours 0, 4, 8, 12 and fecal grab samples at hours -24, 0, 24 and 7 d postchallenge. Blood samples were analyzed for interferonγ (IFNγ), interleukin-8 (IL-8), and haptoglobin (HP) using commercially available ELISA kits and qRT-PCR for genes of interest associated with cytokine expression. Fecal samples were enumerated for Clostridia and E. coli using selective media (≤5 isolates from each media/sample), tested to determine whether they were Clostridium perfringens or pathogenic E. coli, and then enriched for detection of Salmonella. Data were analyzed via ANOVA. During the feeding trial, HP was reduced (P = 0.018) in CEL compared with CON at days 15, 45, and 60, whereas IFNγ and IL-8 did not differ (P > 0.080) between treatments. All cytokines were decreased (P < 0.001) in CEL compared with CON during the challenge. During the feeding trial, HP mRNA was increased (P = 0.045) in CEL compared with CON at days 30 and 60. Similarly, IFNγ mRNA was increased (P = 0.040) in CEL compared with CON; however, other genes of interest did not differ (P > 0.172). Both C. perfringens and total E. coli counts were decreased (P = 0.036) in CEL compared with CON at 24 h after the start of the transportation challenge. Clostridia and pathogenic E. coli counts did not differ (P = 0.941) between treatments. Total Clostridia and E. coli counts were increased (P < 0.014) 24 h postchallenge. All microbial populations, except pathogenic E. coli, observed decreased (P ≤ 0.009) counts from 24 h to 7 d postchallenge. Overall, Celmanax supplementation decreased circulating cytokines, and altered microbial populations and gene expression, thus, may serve a role in preparing animals to better cope with immunological challenges.

Of Whales and Genes: Unraveling the Physiological Response to Stressors in Belugas (Delphinapterus leucas) at the Molecular Level

Marine mammals, now more than ever, are exposed to environmental and anthropogenic stressors. A better understanding of stress physiology in marine mammals is warranted in order to assist in conservation efforts. This study screened gene expression profiles (cytokines, stress-response markers) in blood samples collected opportunistically under controlled conditions from aquarium belugas during transport and introduction to a novel environment (T/NEnv), participation in out-of-water examinations (OWE) and from wild belugas during live capture–release health assessments (WLCR). Quantitative-PCR was used to measure gene expression involved in physiological and immune responses at different time scales. Linear mixed models with repeated measures and pairwise comparisons were used for analysis. Overall, a generalized down-regulation of relative gene expression when compared to samples collected under behavioral control from aquarium whales or to pre-assessment samples of wild whales was observed, with genes IFNγ, IL2, TGFβ and Nr3c1 displaying the largest significant (p < 0.05) changes. Significant (p < 0.05) negative associations of inflammatory gene expression with norepinephrine suggest inhibitory effects of catecholamines on the inflammatory response. Overall, this study contributes to our understanding of the physiological response to stressors at the molecular level in belugas, and the genes suggested here can further be utilized as additional tools in beluga health assessments and monitoring.

The Effects of Stocking Density and Distances on Electroencephalographic Changes and Cortisol as Welfare Indicators in Brahman Crossbred Cattle

The objective of the current study was to investigate the effects of stocking density and distances on electroencephalographic changes and cortisol as welfare indicators in Brahman crossbred cattle. Sixty Brahman crossbred heifers were subjected to road transport from a cattle feedlot farm located in Universiti Putra Malaysia (UPM), Serdang to a commercial ruminant abattoir in Shah Alam, Selangor. Animals were assigned to long (850 km) and short (450 km) distances and high (600 sqm), medium (400 sqm), and low (200 sqm) stocking densities. Results revealed that the intensity of cortisol responses and EEG parameters (such as alpha <0.001, beta < 0.001, delta < 0.001, theta < 0.001, MF < 0.001 and Ptot < 0.001) increased significantly. Long-distance transport also resulted in significantly more intense (<0.001) responses to nociception during slaughter than animals that had been transported over a shorter distance, as indicated by EEG and cortisol.

Appeasing Pheromones against Bovine Respiratory Complex and Modulation of Immune Transcript Expressions

Bovine respiratory disease is still a major concern and has major economic impact. Another consequence of respiratory infections is the use of antimicrobial molecules to control bacterial pathogens. This can participate in the emergence and shedding of antimicrobial resistance that can threaten animal as well as human health. Appeasing pheromones with their capacity to reduce stress and thus their ability to preserve the functions of the immune system have been proposed to reduce the use of antimicrobial substances. In this study, we assessed the effect of appeasing pheromone administration on bovine health and performance during the fattening period. Zootechnical and health parameters and whole blood immune transcript expressions were measured over four weeks in bulls to determine the effect of the pheromone. We observed increased clinical signs on Day 8 (D8) and decreased clinical signs on D30 in bulls who received the pheromone and a higher expression of interleukin 8 transcripts in this group than in the control group on D8. Our results are overall in line with previous reports in livestock species. Further studies are needed to shed more light on the effect of appeasing pheromones and decipher their exact mechanisms of action.

The effects of road transportation with or without homeopathic remedy supplementation on growth performance, apparent nutrient digestibility, fecal microbiota, and serum cortisol and superoxide dismutase levels in growing pigs

The specialization of swine production and the market demand for pigs at different growth stages makes road transportation inevitable. However, road transportation usually causes a stress response in pigs. It is reported that homeopathic remedies supplementation could alleviate the stress response in pigs. This study investigated the effects of road transportation with or without homeopathic remedy (Convermax) supplementation on growth performance, nutrient digestibility, fecal microbiota, and serum cortisol and superoxide dismutase (SOD) concentrations in growing pigs. A total of 180 crossbred 49-d-old growing pigs [(Yorkshire × Landrace) × Duroc] with an initial body weight of 13.17 ± 0.02 kg were randomly allotted to 2 groups based on the initial body weight, containing 18 replicates with 5 pigs (mixed sex) in each. The pigs were fed dietary supplementation of a homeopathic remedy (Convermax) (0 or 200 mg/kg of feed, as-fed) for 35 d. On day 21, 45 pigs (70-d old; 25.25 ± 0.37 kg) were randomly selected from each group and assigned to either 2 hr of road transportation or no road transportation, resulting in a 2 × 2 factorial design. We found that road transportation led to an increase in the fecal coliform bacteria counts (P = 0.023) and serum cortisol concentration (P = 0.039) and a decrease in the serum SOD concentration (P < 0.001). However, supplementing homeopathic remedy (Convermax) to the diet of growing pigs increased gain to feed ratio (P = 0.042), apparent nitrogen digestibility (P = 0.019), and serum SOD concentration (P = 0.007), whereas decreased serum cortisol concentration (P = 0.022). In brief, road transportation induced stress response for growing pigs and increased harmful bacteria counts in their intestines. Dietary supplementation of homeopathic remedy (Convermax) alleviated stress response, improved apparent nitrogen digestibility, and increased gain to feed ratio. However, no significant interactive effects between road transportation with or without dietary homeopathic remedy (Convermax) levels were observed on the detected parameters in growing pigs.

Arrival cortisol measurement in veal calves and its association with body weight, protein fractions, animal health and performance

Male dairy calves are exposed to an accumulation of transport, social and environmental stressors while transferred to fattening units. As a consequence, calves show high cortisol concentrations upon arrival at the veal facility. Whether cortisol levels as measured on arrival can be associated with animal health, welfare and production results is currently unknown. The first objective of this prospective cohort study was to determine possible associations of arrival serum cortisol concentration with health and production variables of veal calves and other arrival predictors like body weight and γ-globulin concentration. The second aim was to investigate potential clustering of arrival risk factors in veal calves for developing bovine respiratory disease (BRD) based on arrival body weight, serum cortisol concentration, total protein and protein fractions. In total, 105 male Holstein calves from two consecutive production cycles in a single, commercial white veal farm were blood sampled directly at arrival on the farm to determine serum cortisol, total protein and protein fractions. All calves were weighed the day after arrival and clinical signs, average daily weight gain (ADG) and carcass weight were collected. Also, all calves of both production cohorts were repeatedly examined by thoracic ultrasonography at the onset of group respiratory disease symptoms (2-3 weeks after arrival) and four weeks later. Linear and logistic mixed models together with k-means clustering were used for statistical analyses. Calves showed on average high, but individually variable serum cortisol concentrations (mean value = 96.6 ng/mL ± standard deviation (SD) = 48.8; Range (R) = 50.0-317 ng/mL). Arrival cortisol, body weight and γ-globulin content were not significantly associated. Serum cortisol and albumin concentrations at arrival were associated with chronic, unresponsive pneumonia. For each increase of serum cortisol concentration by 10 ng/mL, the odds for lung consolidation of ≥1 cm in depth at the second ultrasonography increased, odds ratio (OR) = 1.03 (95 % confidence interval (CI) = 1.01-1.06; P < 0.050). For every decrease in serum albumin concentration by 1g/L, the OR for developing pneumonia was 1.23 (95 % CI= 1.04-1.46; P < 0.015). Additionally, two clusters of calves were identified based upon arrival status: a low risk cluster with below average stress-induced cortisol values, above average body weight, no acute phase response (APR) and no failure of passive immune transfer (FPIT), and a high risk cluster with above average cortisol values, below average body weight, APR and FPIT. High risk calves had higher odds for developing clinical BRD (OR= 3.88 (95 % CI=1.20-12.53; P < 0.020)) and lung consolidation ≥1 cm in depth at week 6-7 after arrival (OR= 3.93 (95 % CI=1.34-11.53; P < 0.013)). Avoiding high cortisol levels upon arrival of calves is important for animal welfare, but also for reduction of the prevalence of chronic, unresponsive pneumonia and the associated need for (repeated) antimicrobial treatment and production losses.

Do Dehydroepiandrosterone (DHEA) and Its Sulfate (DHEAS) Play a Role in the Stress Response in Domestic Animals?

In animal husbandry, stress is often associated with poor health and welfare. Stress occurs when a physiological control system detects a state of real or presumptive threat to the animal's homeostasis or a failure to control a fitness-critical variable. The definition of stress has mostly relied on glucocorticoids measurement, even though glucocorticoids represent one stress-response system, the hypothalamus-pituitary-adrenocortical axis, which is not precise enough as it is also related to metabolic regulation and activated in non-stressful situations (pleasure, excitement, and arousal). The mammal adrenal can synthesize the androgenic steroid dehydroepiandrosterone (DHEA) and its sulfate metabolite (DHEAS), which have been associated to the stress response in several studies performed mostly in humans and laboratory animals. Although the functions of these steroids are not fully understood, available data suggest their antagonistic effects on glucocorticoids and, in humans, their secretion is affected by stress. This review explores the scientific literature on DHEA and DHEAS release in domestic animals in response to stressors of different nature (inflammatory, physical, or social) and duration, and the extra-adrenal contribution to circulating DHEA. Then, the potential use of DHEA in conjunction with cortisol to improve the definition of the stress phenotype in farmed animals is discussed. Although the focus of this review is on farmed animals, examples from other species are reported when available.

Dietary supplementation with oregano essential oil and monensin in combination is antagonistic to growth performance of yearling Holstein bulls

Our previous work indicated that feeding oregano essential oil (OEO) in combination with monensin (MON) may not be mutually beneficial to dairy calf growth performance. To evaluate this observation further, a 240-d long-term growth experiment was conducted using 12 young growing Holstein bulls using a 2 × 2 factorial treatment arrangement. Main factors were OEO and MON arranged in 4 individual treatments: (1) ration fed without OEO or MON (control), (2) OEO fed at 26 mg/kg of dry matter (DM), (3) MON fed at 25 mg/kg of DM, and (4) OEO and MON fed in combination (OEO+MON). Holstein bulls were 70 d of age and similar in body weight (BW; 93.3 ± 4.54 kg) and individually fed for 240 d. The targeted feeding rates of OEO and MON were blended into 200 g of concentrate and top dressed each morning to a corn stalklage-based ration. Body weights, frame measurements, and blood samples were collected monthly. Interactions of OEO by MON were detected for BW, BW gain, average daily gain, and a trend for feed conversion. Bulls fed OEO or MON demonstrated greater final BW (368, 385, 381, and 358 kg for control, OEO, MON, and OEO+MON, respectively), and BW gains (278, 292, 285, and 265 kg) and average daily gain (1.16, 1.22, 1.19, 1.11 kg/d) were greatest for bulls fed OEO or MON compared with bulls fed OEO+MON; bulls fed the control were intermediate and similar to bulls fed MON. Intake of DM was greater for bulls fed OEO (6.55, 6.99, 6.60, and 6.42 kg/d) compared with bulls fed remaining treatments. Frame growth gain measurements for heart girth, abdominal girth, withers height, body length, and cannon bone circumference were similar for bulls fed all treatments. Serum triglyceride (0.23, 0.25, 0.28, and 0.24 mmol/L) concentrations were greater for bulls fed MON compared with bulls fed the control and OEO+MON, and bulls fed OEO were intermediate and similar. Cholesterol (2.06, 2.29, 2.20, and 2.07 mmol/L) concentrations were greater for bulls fed OEO compared with bulls fed the control and OEO+MON, and bulls fed MON were intermediate and similar. Serum antioxidant measurements were similar for bulls fed all treatments. Serum IgA, IgG, and IgM concentrations were similar for bulls fed all treatments. Feeding OEO or MON separately can improve growth performance of growing Holstein bulls. We do not know why the combination of OEO and MON is antagonistic to growth performance of Holstein bulls. However, these technologies should not be fed in combination to growing dairy cattle.

Preconditioning beef cattle for long-duration transportation stress with rumen-protected methionine supplementation: A nutrigenetics study

In general, beef cattle long-distance transportation from cow-calf operations to feedlots or from feedlots to abattoirs is a common situation in the beef industry. The aim of this study was to determine the effect of rumen-protected methionine (RPM) supplementation on a proposed gene network for muscle fatigue, creatine synthesis (CKM), and reactive oxygen species (ROS) metabolism after a transportation simulation in a test track. Angus × Simmental heifers (n = 18) were stratified by body weight (408 ± 64 kg; BW) and randomly assigned to dietary treatments: 1) control diet (CTRL) or 2) control diet + 8 gr/hd/day of top-dressed rumen-protected methionine (RPM). After an adaptation period to Calan gates, animals received the mentioned dietary treatment consisting of Bermuda hay ad libitum and a soy hulls and corn gluten feed based supplement. After 45 days of supplementation, animals were loaded onto a trailer and transported for 22 hours (long-term transportation). Longissimus muscle biopsies, BW and blood samples were obtained on day 0 (Baseline), 43 (Pre-transport; PRET), and 46 (Post-transport; POST). Heifers' average daily gain did not differ between baseline and PRET. Control heifer's shrink was 10% of BW while RPM heifers shrink was 8%. Serum cortisol decreased, and glucose and creatine kinase levels increased after transportation, but no differences were observed between treatments. Messenger RNA was extracted from skeletal muscle tissue and gene expression analysis was performed by RT-qPCR. Results showed that AHCY and DNMT3A (DNA methylation), SSPN (Sarcoglycan complex), and SOD2 (Oxidative Stress-ROS) were upregulated in CTRL between baseline and PRET and, decreased between pre and POST while they remained constant for RPM. Furthermore, CKM was not affected by treatments. In conclusion, RPM supplementation may affect ROS production and enhance DNA hypermethylation, after a long-term transportation.

Dynamic ROS Production and Gene Expression of Heifers Blood Neutrophil in a Oligofructose Overload Model

Alimentary oligofructose (OF) overload can induce several diseases in cattle, such as ruminal acidosis, laminitis, and synovitis. The role of blood polymorphonuclear neutrophil (PMN) remains unclear during OF overload. The aim of this study was to investigate the dynamic changes in reactive oxygen species (ROS) production and the expression profile of genes in blood PMN in a model of OF overload. Twelve clinically healthy and non-pregnant Chinese Holstein heifers, aged between 18 and 26 mo, weighing 335–403 kg, BCS (5-point scale) ranges 2.7–3.3 were used for the experiments. OF heifers (n = 6) received 17 g/kg of BW oligofructose dissolved in 2 L/100 kg of BW tap water and the CON heifers (n = 6) received 2 L/100 kg of BW tap water. Blood PMN was isolated for each heifer 0, 6, 12, 18, 24, 36, 48, 60, and 72 h after administration. PMN was analyzed either by endogenous and phorbol myristate acetate (PMA)-induced ROS production or by quantitative real-time PCR. After 12 h, PMA-induced ROS production decreased, which was sustained until 48 h. The expressions of inflammation markers (IL1α, IL1β, IL6, IL10, TNFα, STAT3, TLR4, MMP9, and HP) and eicosanoids (ALOX5, ALOX5AP, and PLA2G4A) were upregulated. The expression of adhesion and migration (CXCR2, CXCL8, CD62L, ITGA4, ITGAM, and ITGB2) in OF heifers was increased compared with CON heifers. The expression of oxidative stress (SOD2 and S100A8) was upregulated, while SOD1 and MPO were downregulated. In metabolism and receptor genes, the expressions of GRα and INSR decreased after 12 h, while Fas increased until 6 h and then decreased at 18 h. The expression of LDHA and PANX1 did not show any differences after OF overload. These findings indicate that OF overload induced systemic activation of PMN, which provides a step toward a better understanding of the role of innate immune responses in response to oral OF administration.

Cardiac vagal tone, plasma cortisol, and dehydroepiandrosterone response to an ACTH challenge in lame and nonlame dairy cows

We studied the adrenocortical and vagal tone responses to a single ACTH challenge in lame (n = 9) vs nonlame (n = 9) dairy cows. Cows were paired according to parity, days in milk, and milk yield. Plasma cortisol and dehydroepiandrosterone concentrations and cardiac vagal tone response (high-frequency component of heart rate variability) were compared after intravenous ACTH administration. Baseline, minimum or maximum, amplitude of the response and area under the response curve were compared. No difference was detected between groups in the cortisol response. Dehydroepiandrosterone was irresponsive to ACTH treatment, and concentrations did not differ between lame and nonlame cows. Vagal tone decreased in response to the ACTH treatment. High frequency component of heart rate variability was lower in the lame group at all sampling times. Lameness was associated with delayed return to baseline. We concluded that the adrenal response capacity is not influenced by lameness, which supports the concept of lameness being a chronic intermittent rather than a chronically persistent stressor. Dehydroepiandrosterone concentrations were not proven to be useful indicators of hypothalamus-pituitary axis dysfunction in cattle. A decreased vagal contribution to heart rate variability-possibly coupled with increased sympathetic modulation-was observed in lame cows, which suggests that lameness affects the mechanisms underlying the action of ACTH on cardiovascular activity.

Transportation and Routine Veterinary Interventions Alter Immune Function in the Dog

Rapid activation of the hypothalamic pituitary adrenal axis and the sympathetic nervous system are hallmarks of the acute stress response and these systems interact with the immune system by signaling though glucocorticoid and adrenergic receptors on immune cells. There is limited information about the effect of these physiologic responses on immunologic parameters of pet dogs enrolled in clinical studies. The objective of this study was to evaluate how travel, instrumentation, and hospitalization alter immunologic parameters in pet dogs. Blood was collected from healthy dogs in a home environment and from healthy dogs at the time of presentation to the hospital and after instrumentation and 24 hours of hospitalization. We found that lipopolysaccharide (LPS)-induced downregulation of toll like receptor 4 (TLR4) was blunted in dogs exposed to stress. Neutrophil and monocyte major histocompatibility complex class II (MHCII) expression increased after transportation to the veterinary hospital but then became similar to that of the control dogs at the end of hospitalization. Peripheral blood mononuclear cell cytotoxicity function was blunted in dogs exposed to the stress of transportation as well as hospitalization. Neutrophil apoptosis was greater in dogs exposed to stress compared to controls although this effect significantly decreased after hospitalization stress. Conversely, stress did not alter induced or spontaneous cytokine production from leukocytes, neutrophil or monocyte expression of TLR4, LPS-induced downregulation of monocyte TLR4, LPS-induced neutrophil and monocyte expression of MHCII or peripheral blood lymphocyte phenotype. Transportation and instrumentation/hospitalization stress should be considered when interpreting immunologic studies in pet dogs.

The Effects of Sea and Road Transport on Physiological and Electroencephalographic Responses in Brahman Crossbred Heifers

The objective of the current study was to evaluate the effects of sea and road transport on the acute phase proteins (APP), cortisol, metabolic, haematological and electroencephalographic (EEG) responses of Brahman crossbred heifers. Sixty Brahman crossbred heifers were subjected to 14 d of transportation by sea from Darwin Port, Australia, to Pasir Gudang Port, Johor, Malaysia, and 330 km of road transportation. Results revealed that the intensity of response for most blood biochemical parameters increased significantly and were different from the baseline values taken while the animals were in Darwin Port, Australia. Haematological results obtained also revealed a significant increase and were different from the baseline values. Cortisol and APP (bovine alpha 1-acid glycoprotein and serum amyloid-A) values increased significantly and were different from the baseline values. Haematological parameters, APP, cortisol and EEG data (alpha, beta, delta and theta waves, total power and median frequency) decreased significantly following 4 and 7 days post-transport, suggesting a recovery of the animals from the stressfulness of transport. In conclusion, the current results revealed that the concentrations of biochemical and haematological parameters, cortisol, APP and EEG data were affected by both sea and road transport as evidenced by the significant changes recorded from the parameters above.

Randomized field trial on the effects of body weight and short transport on stress and immune variables in 2- to 4-week-old dairy calves

Background

Whether underweight calves respond differently to transport stress, enhancing their disease risk, is currently unknown.

Objective

To determine the effects of low body weight and transport stress on immune variables.

Animals

Twenty‐one 2‐ to 4‐week‐old male Holstein calves, housed on a commercial farm.

Methods

Randomized clinical trial. Full factorial design with 4 treatment groups: low body weight (≤46 kg)/no transport (LOWCON); low body weight/transport (LOWTRANS); normal body weight (>46 kg)/no transport (NORMCON), and normal body weight/transport (NORMTRANS). Transport duration was 2 hours.

Results

Transport significantly increased serum cortisol concentration (77.8 μg/mL; 95% confidence interval [CI], 37.8‐131.6; P < .001), interleukin (IL)‐17A (344.9 pg/mL; 95% CI, 32.2‐556.5; P = .04), and tumor necrosis factor‐α (TNF‐α) (218.2 pg/mL; 95% CI, 32.5‐368.3; P = .03) production after lipopolysaccharide (LPS) stimulation. Body weight did not affect any of the studied variables. However, the interaction of transport and body weight was significant. LOWTRANS calves showed increased monocyte count (2.0 × 10⁹/L; 95% CI, 0.6‐4.2; P < .05) and interleukin IL‐17A production (106.0 pg/mL; 95% CI, 4.2‐306.9; P = .03) compared to normal weight calves and increased TNF‐α production (275.6 pg/mL; 95% CI, 2.6‐463.0; P = .02) compared to LOWCON calves in unstimulated peripheral blood mononuclear cells (PBMCs) after transport.

Conclusion and Clinical Importance

These findings contribute to our understanding of increased disease susceptibility of underweight calves when transported. Gamma globulin concentration was identified as important interfering factor in studies on immune variables in neonatal calves.

Effect of posttransportation grazing on the physiological condition and meat quality traits of Black Bengal goats

This study was designed to reveal the role of posttransportation grazing on the physiological condition and meat quality traits of Black Bengal goats. Twenty-four castrated male Black Bengal goats were divided into a control (untransported) group and three treated groups: Walking and Transportation with Human Interference group (WTHI) (30 min walking before 6 hr transport and then 30 min walking with human interference), posttransportation grazing for 48 hr (PTG1), and posttransportation grazing for 72 hr (PTG2). The WTHI and PTG1 groups had a significant reduction in their blood concentrations of tri-iodothyronine (T₃ ) and thyroxine (T₄ ), and a significantly higher neutrophil and lymphocyte (N:L) ratio compared with those of the control group. Blood concentrations of T₃ and T₄ and the N:L ratio of PTG2 returned to the control level after 72 hr of grazing. The final pH and water-holding capacity values of meat were significantly higher in the WTHI group than in the control group, but those in the PTG2 group returned to the control level after 72 hr of grazing. These results demonstrate that posttransportation grazing for 72 hr is effective for recovering from damage induced by transportation stress.

Invited review: Relationship between cattle transport, immunity and respiratory disease

The association between transportation and the occurrence of the bovine respiratory disease complex (BRDC) has long been recognised. Many hypotheses regarding this association have been declared through the past decades, and it is agreed upon by most researchers that the multiple stressors that calves experience during transportation result in an overall immunosuppression that allows the respiratory tract to be invaded by numerous opportunistic pathogens. Furthermore, the innate immune cells, neutrophils, may be trapped in a paradox whereby their crucial defence and pathogen-killing activities are counteracted by excessive inflammation and tissue damage that may exacerbate disease, including the BRDC. Neutrophilia in response to glucocorticoids has been attributed to an influx of immature neutrophils newly released from the bone marrow, a decrease in neutrophil margination along endothelial walls, and a decrease in neutrophil apoptosis. Several of these explanations have been confirmed by altered expression of genes and proteins important for neutrophil margination and apoptosis.

Investigation of the physiological, behavioral, and biochemical responses of cattle to restraint stress

Stresses imposed on livestock have significant impact on their health and productivity as well as public perceptions of animal welfare. Understanding stress responses in livestock may help refine management procedures and facilitate selection of stress-tolerant animals. In this study, behavioral (chute entry order, chute behavior, and exit velocity), physiological (serum cortisol), and biochemical (kinome) responses were evaluated in cattle ( = 20) subjected to three 5-min restraint periods with weekly intervals. Correlations among stress responses were assessed across all animals as well as for subgroups ( = 4) representing animals consistently displaying a high and low extreme of serum cortisol responses. Across all animals, entry order ( = 0.006) and exit velocity ( = 0.023) were positively correlated with serum cortisol; however, these correlations were not consistently reproducible for the high and low serum cortisol responders. Kinome profiling of peripheral blood mononuclear cells revealed distinct signaling events between the high and low cortisol responders. In particular, kinome profiling revealed significant differences in carbohydrate metabolism and apoptosis that were independently validated. Furthermore, changes in serum glucose levels provided a reliable, inexpensive indicator of serum cortisol levels and often had greater predictive value than cortisol for stress-related behavioral responses. Serum cortisol levels displayed a pattern consistent with sensitization, whereas no habituation or sensitization was observed for serum glucose levels or behavioral responses. Collectively, this investigation provides insight into correlations among physiological, behavioral, and biochemical responses of cattle subjected to a brief restraint that may provide biomarkers for selection of stress-tolerant animals.

Interleukin 6 increases the in vitro expression of key proteins associated with steroidogenesis in the bovine adrenal zona fasciculata

In this study, the in vitro effects of interleukin 6 (IL-6) on the messenger RNAs (mRNAs) and proteins for key steroidogenic factors in the bovine adrenal zona fasciculata (ZF) were determined. Bovine adrenal glands were obtained from an abattoir, and the ZF was isolated. Strips of ZF were then exposed to different concentration of murine IL-6 and/or adrenocorticotropic hormone (ACTH) for various intervals, the protein and mRNA extracted, and the mRNA and protein expression determined by real-time polymerase chain reaction and Western blots. Exposure (1 h) to IL-6 increased in a concentration-dependent manner (10-pg IL-6/mL, P < 0.05 vs control; 100-pg IL-6/mL, P < 0.01 vs control) the relative expression of the mRNAs and proteins for steroidogenic acute regulatory protein (StAR), cholesterol side-chain cleavage enzyme (P450scc), 3β hydroxysteroid dehydrogenase type 2 (3β HSD), 17α-hydroxylase/17,20-lyase/17,20-desmolase (P450 17OH), steroid 21-hydroxylase (P450 21OH), steroid 11-β-hydroxylase type 1 (P450 11βOH), and steroidogenic factor 1 (SF-1), a nuclear factor that increases StAR and steroidogenic enzymes (SEs) expression. Similarly, IL-6 (10 pg/mL) increased the relative expression of proteins and mRNAs for StAR, P450scc, 3β HSD, P450 17OH, P450 21 OH, P450 11βOH, and SF-1 in a time-dependent manner (30 min, P < 0.05 vs control; 60, 120, and 240 min, P < 0.01 vs control). In contrast, IL-6 decreased in a concentration-dependent (P < 0.01 vs control for 1, 10, and 100 pg IL-6/mL) and time-dependent (P < 0.05 vs control for 30, 60,120, and 240 min of 10 pg IL-6/mL) manner the relative expression of the mRNA and protein for adrenal hypoplasia congenita-like protein (DAX-1), a nuclear factor that decreases expression of StAR and SEs. Incubation (1 h) of ZF with 100-nM ACTH increased (P < 0.05 vs control) the relative expression of StAR, P450scc, 3β HSD, P450 17OH, P450 21OH, P450 11βOH, and SF-1 and decreased (P < 0.01 vs control) the relative expression of DAX-1. Murine IL-6 (10 pg/mL) augmented (P < 0.05 vs ACTH) both the stimulatory and inhibitory effects of ACTH. Bovine IL-6 (100 pg/mL, 1-h incubation) also increased (P < 0.01 vs control) the relative expression of the proteins for StAR, P450scc, and SF-1 and decreased (P < 0.01 vs control) the relative expression of DAX-1. In summary, IL-6 increased ZF expression of StAR and 5 SEs, which may be mediated in part by decreasing DAX-1 expression and increasing SF-1 expression.

Interleukin-6 inhibits adrenal androgen release from bovine adrenal zona reticularis cells by inhibiting the expression of steroidogenic proteins

Interleukin-6 (IL-6) is secreted by adrenocortical cells and modifies cortisol secretion. In this study, the effects of IL-6 on adrenal androgen release were investigated. The zona reticularis (ZR) was generally isolated from bovine adrenal glands by dissection. In select experiments, the intact adrenal cortex (ie, all 3 adrenocortical zones) was dissected from the adrenal glands. For androgen release experiments, ZR and intact adrenocortical cubes were dispersed into isolated cells, the cells cultured and exposed to IL-6 and/or adrenocorticotropic hormone (ACTH), and androgen release determined by radioimmunoassay. Basal and ACTH-stimulated androgen release from the ZR was inhibited by IL-6 in a concentration-dependent (10-1000 pg/mL) and time-dependent (4-24 h) manner (P < 0.01 by 1-way analysis of variance and the Bonferroni test). In contrast, IL-6 increased basal and ACTH-stimulated androgen release from mixed adrenocortical cells (P < 0.01). The mechanism of IL-6 inhibition of androgen release was investigated by exposing ZR strips to IL-6 and measuring the expression of the messenger RNA (mRNA) and protein of steroidogenic factors. Basal and ACTH-stimulated expression of the mRNA and protein for steroidogenic acute regulatory protein, cholesterol side chain cleavage enzyme, 3-β-hydroxysteroid dehydrogenase type 2, steroid 17-α-hydroxylase/17,20 lyase/17,20 desmolase, and the nuclear factor steroidogenic factor 1 (SF-1), that stimulates steroidogenesis, were decreased by IL-6 (P < 0.01). In contrast IL-6 increased the mRNA and protein for dosage-sensitive sex reversal, adrenal hypoplasia critical region, on chromosome X, gene 1 (DAX-1), a nuclear factor that inhibits steroidogenesis (P < 0.01). In summary, IL-6 decreased androgen release and the expression of steroidogenic factors in the ZR, and this decrease may be mediated in part through increasing DAX-1 and decreasing SF-1.

Differences in leukocyte profile, gene expression, and metabolite status of dairy cows with or without sole ulcers

Sole ulcers are one of the most severe pathologies causing lameness in dairy cows and are associated with abnormal behavior and impaired production performance. However, little is known about how or whether lameness caused by sole ulcers affects the cow systemically. This study compared hematology profile, leukocyte gene expression, and physiological responses [metabolite, cortisol, the endogenous steroid hormone dehydroepiandrosterone (DHEA), and haptoglobin concentrations] of cows with sole ulcers and healthy cows. Twelve clinically lame cows (lame) were identified as having at least one sole ulcer and no other disorder, and matched with a cow that had good locomotion and no disorders (sound), using days in milk, liveweight, body condition score, and diet. Blood samples were taken from all 24 cows within 24h of sole ulcer diagnosis. Leukocyte counts were obtained using an automated cell counter, cortisol and DHEA concentration by ELISA, and plasma haptoglobin, urea, total protein, creatine kinase, and glucose were analyzed on an Olympus analyzer. Expression of 16 genes associated with lameness or stress were estimated using reverse transcription-PCR. Data were analyzed using the MIXED procedure in SAS software (version 9.3; SAS Institute Inc., Cary, NC). Lame cows had a higher neutrophil percentage, a numerically lower lymphocyte percentage, and tended to have a higher neutrophil:lymphocyte ratio than sound cows. Serum cortisol and DHEA concentrations were higher in lame than in sound cows. Lame cows also tended to have higher haptoglobin and glucose levels than sound, as well as higher protein yet lower urea levels. Sound cows tended to have higher relative expression of the gene coding for colony-stimulating factor 2 than lame, but in all other cases where differences were detected in cytokine gene expression (IL-1α, IL-1β, CXCL8, and IL-10), relative gene expression in sound cows tended to be, or was, lower than in lame. Relative expression of MMP-13, GR-α, Fas, haptoglobin, and CD62L were, or tended to be, higher in lame than sound cows. A high neutrophil:lymphocyte ratio in combination with higher cortisol levels in cows with ulcers is indicative of physiological stress. Moreover, increased DHEA and a higher cortisol:DHEA ratio, as well as a tendency for higher haptoglobin levels and increased haptoglobin mRNA expression, are indicative of systemic inflammation. Increased cytokine mRNA expression indicates activation of the immune system compared with healthy cows. Increased expression of MMP-13 mRNA has been found in cows with impaired locomotion and thus could be implicated in development of claw horn disorders.

Examination of the bovine leukocyte environment using immunogenetic biomarkers to assess immunocompetence following exposure to weaning stress

BACKGROUND

The molecular mechanisms by which stress induces the development of pathologies remains unclear, although it is recognised that one of the major factors affecting health as a consequence of stress is the involvement of the neuroendocrine system. In cattle, a number of necessary husbandry practices have been shown to activate the stress response, yet very little is known about the impact these have at the molecular level. The objectives of the study were to characterise, in male and female beef calves, the immune response to weaning stress in bovine leukocytes at the physiological and molecular levels and to assess the difference between calves weaned in the presence of the dam and those weaned and penned away from the dam.

RESULTS

Following exposure to weaning stress, total neutrophil number and neutrophil:lymphocyte (N:L) ratio increased (P < 0.01) in calves. Additionally, expression of pro-inflammatory cytokine genes, including IL-1β, IL-8, IFN-γ and TNFα, were up-regulated (P < 0.01). Furthermore, there was increased (P < 0.001) expression of the glucocorticoid receptor, GRα, the pro-apoptotic gene, Fas and the Gram-negative pattern recognition receptor, TLR4. Calves penned away from the dam post-weaning had increased (P < 0.01) neutrophil number and N:L ratio compared with calves penned next to the dam, and female calves had higher (P < 0.05) expression levels of IL-2, IL-8, IFN-γ and TNFα than male calves.

CONCLUSIONS

Weaning elicits an immediate and somewhat short-lived acute stress response in the calf. The effects serve to enhance, rather than suppress, the immune response by means of a heightened inflammatory response and cellular mobilization. The earlier and more profound increase in neutrophil number and N:L ratio together with reduced lymphocyte number in calves penned away compared with calves penned near their dams post-weaning suggests that the former may be more sensitive to weaning stress. The data also show a clear effect of gender in differential gene expression in response to stress with IFN-γ having increased expression in female calves compared with male calves over the course of the study. Additionally, this study has helped to characterise the inflammatory response to stress in calves and identify a number of novel candidate biomarkers suitable for investigation in future studies of stress.

Ethanol increases HSP70 concentrations in honeybee (Apis mellifera L.) brain tissue

Previous research on the honeybee ethanol model established how acute ethanol exposure altered function at different levels of organization: behavior and learning, ecology, and physiology. The purpose of this study was to evaluate whether ethanol doses that affect honeybee behavior also induce a significant stress response, measured by heat shock protein 70 (HSP70) concentrations, in honeybee brain tissues. Experiment 1 examined how pretreatment handling influenced brain HSP70 concentrations in three pretreatment groups of bees; immediately after being collected, after being harnessed and fed, and after 22-24h in a harness. HSP70 concentrations did not differ among pretreatment groups within replicates, although we observed significantly different HSP70 concentrations between the two replicates. Experiment 2 investigated the relationship between ethanol dose and brain HSP70 concentrations. Bees were placed in seven experimental groups, the three pretreatment groups as in Experiment 1 and four ethanol-fed groups. Bees in ethanol treatments were fed 1.5M sucrose (control) and 1.5M sucrose-ethanol solutions containing 2.5, 5, and 10% ethanol, allowed to sit for 4h, and dissected brains were assayed for HSP70. We observed ethanol-induced increases in honeybee brain HSP70 concentrations from the control group through the 5% ethanol group. Only bees in the 5% ethanol group had HSP70 concentrations significantly higher than the control group. The inverted U-shaped ethanol dose-HSP70 concentration response curve indicated that ingestion of 2.5% ethanol and 5% ethanol stimulated the stress response, whereas ingestion of 10% ethanol inhibited the stress response. Doses that show maximum HSP70 concentration (5% ethanol) or HSP70 inhibition (10% ethanol) correspond to those (> or =5% ethanol) that also impaired honeybees in previous studies. We conclude that acute ethanol intoxication by solutions containing > or =5% ethanol causes significant ethanol-induced stress in brain tissue that impairs honeybee behavior and associative learning.

The effect of floor surface on dairy cow immune function and locomotion score

This study evaluated the effect of 2 dairy cow housing systems on cow locomotion, immune status, and expression of genes associated with lameness during the dry and periparturient periods. Cows were assigned to freestall housing with either rubber (RUB; n = 13) or concrete (CON; n = 14) at the feed-bunk and alley immediately after their first calving, and managed on this system during all subsequent lactations. At dry off, cows were moved to a straw bedded-pack dry cow pen, and remained there until about 2 d before subsequent calving. To investigate whether greater exposure to RUB or CON increased the differences between cows on each treatment, cows at the end of either their first (n = 16) or second (n = 11) lactations were included in the experiment. Locomotion scores and blood samples were obtained at -60 (beginning of the dry period), -30, 0 (after calving), +10 and +18 d relative to calving. Leukocyte counts were obtained by using an automated cell counter. Phagocytic activity, and cells positive for CD14 and CD18 expression were measured by flow cytometry using labeled microbeads and antibodies. Expression of tachikinin 1(TAC1), histamine receptor 1 (H1), and metalloproteinase (MMP)13 in blood leukocytes was estimated using quantitative real-time PCR. Treatment effects were determined using a repeated measures model. Provision of rubber flooring did not improve dairy cow locomotion during the subsequent study period. However, time relative to calving had an effect on locomotion score and speed, which were worst on d 0, probably because of the discomfort associated with calving. An interaction occurred between treatment and time for neutrophil and lymphocyte counts. The RUB cows had greater neutrophil and lesser lymphocyte numbers postpartum than CON. These cows also had more cells positive for CD14 postpartum compared with prepartum. Moreover, RUB cows showed upregulation of MMP13 and TAC1 compared with CON. These genes are associated with lameness and pain detection respectively. Greater neutrophil to lymphocyte ratios and CD14 expression are associated with physiological stress or with activated immunity. Rubber flooring is associated with an increase in activity and standing. This may have resulted in indications of physiological stress and upregulation of genes associated with lameness and pain for RUB cows. However, this study did not take into account the long-term effects of concrete or rubber flooring; for instance, occurrence of lameness or survivability within the herd.

Modern approaches to understanding stress and disease susceptibility: A review with special emphasis on respiratory disease

Studies in animals and humans link both physical and psychological stress with an increased incidence and severity of respiratory infections. For this manuscript we define stress as the physiological responses an individual undergoes while adjusting to a continually changing environment. It is known that stressors of various types (psychological/physical) can alter the physiological levels of certain hormones, chemokines and cytokines. These alterations send information to the central nervous system to take necessary action which then sends messages to appropriate organs/tissues/cells to respond. These messages can either activate or suppress the immune system as needed and failure to compensate for this by the body can lead to serious health-related problems. Little is known how stress affects disease susceptibility, yet understanding this mechanism is important for developing effective treatments, and for improving health and food quality. The current review focuses on (a) the effects of psychological stressors in humans and animals, (b) various methodologies employed to understand stress responses and their outcomes, and (c) the current status of the attempts to correlate stress and disease with respiratory disease as model system. The methodologies included in this review span traditional epidemiological, behavioral and immunological studies to current high throughput genomic, proteomic, metabolomic/metabonomic approaches. With the advent of various newer omics and bioinformatics methodologies we postulate that it will become feasible to understand the mechanisms through which stress can influence disease onset. Although the literature in this area is limited because of the infancy of this research area, the objective of this review is to illustrate the power of new approaches to address complex biological questions. These new approaches will also aid in our understanding how these processes are related to the dynamics and kinetics of changes in expression of multiple genes at various levels.

Transportation of young beef bulls alters circulating physiological parameters that may be effective biomarkers of stress

Transportation causes stress in cattle that may alter numerous physiological variables with a negative impact on production and health. The objectives of the current study were to investigate the physiological effects of truck transportation and to characterize a pattern of phenotypes in the circulation that may aid in the early identification of stress-susceptible animals that often succumb to severe respiratory disease. Thirty-six young beef bulls (Aberdeen Angus, n = 12; Friesian, n = 12; and Belgian Blue x Friesian, n = 12) were subjected to a 9-h truck transportation by road. Blood (10 mL) was collected at -24, 0, 4.5, 9.75, 14.25, 24, and 48 h relative to the initiation of transportation (0 h). Plasma was collected for the assay of various metabolic, inflammatory, and steroid variables, and total leukocyte counts were determined in whole blood at each time point. Body weight and rectal temperature were recorded at -24, 9.75, and 48 h. Transportation decreased measures of protein metabolism in the plasma, including albumin (P = 0.002), globulin (P < 0.001), urea (P = 0.006), and total protein (P < 0.001), and increased creatine kinase (P < 0.001). The energy substrate beta-hydroxybutyrate was not changed (P = 0.27). Acute phase proteins haptoglobin and fibrinogen were both decreased (P < 0.001), whereas total leukocyte counts were elevated (P = 0.002). Circulating steroid concentrations were altered, because a classical acute increase in plasma cortisol was observed with the onset of transit (P < 0.001), in association with a decrease in dehydroepiandrosterone (P = 0.07), resulting in a profound increase in cortisol:dehydroepiandrosterone ratio (P < 0.001). Plasma testosterone was decreased, whereas plasma progesterone was increased (P < 0.001) in association with the increase in cortisol (P < 0.001). There was also an effect of breed for all variables except plasma urea, creatine kinase, and testosterone, perhaps indicating that a genetic component contributed to the physiological response to transportation stress, although without any clear trend. Taken together, this profile of physiological variables in the circulation of transportation-stressed bulls may aid in the future detection of disease-susceptible cattle after transportation. Further research to validate these potential biomarkers is necessary.