Exploration of the hypothalamic–pituitary–adrenal function as a tool to evaluate animal welfare

Growth performance in pigs derived from in vitro produced embryos is enhanced compared to their artificial insemination-derived counterparts from birth to adulthood

Research suggests that assisted reproductive technologies may lead to adverse effects on the offspring. To date, long-term effects from fetal development through adulthood have been scarcely researched. In the present observational study, we aimed to describe growth (body weight, BW; crown-rump length, CRL; and average daily gain, ADG), and growth-related hormone levels (growth hormone, GH; insulin-like growth factor 1, IGF-1; thyroxine, T4; cortisol) of pigs derived from artificial insemination (AI) and from embryos produced in vitro under two different conditions, C-IVP, with Bovine Serum Albumin (BSA), and RF-IVP, with reproductive fluids and BSA, as protein source in culture, from birth to 5 years of age. In vitro-produced animals showed greater BW, CRL and ADG than AI. Additionally, C-IVP animals had greater BW, CRL and ADG than RF-IVP up to 6 months of age. Regarding hormones, GH concentration was greater in RF-IVP compared to AI and C-IVP. In males, IGF-1 levels of RF-IVP were greater than those of AI. Instead, T4 levels of AI males were greater than C-IVP and RF-IVP. Males showed greater IGF-1 and GH than females, the latter only from 1 year old. Instead, females had greater T4 concentration than males. No differences in cortisol were observed between groups or sexes. In conclusion, this study sets reference values of growth and hormone concentrations for adult pigs that are missing in literature. Although the differences observed between the experimental groups were within physiological ranges, there was a greater growth performance in the IVP groups.

Sarcoptic mange in cattle: Effects of treatment with eprinomectin topical solution on performance, behavior changes, and adrenal and systemic responses to ACTH challenge

Bovine sarcoptic mange can cause significant pruritus and skin disease which compromise the health and welfare of the animals, impairs animal productivity and is furthermore of zoonotic concern. This study was conducted to evaluate the effects of efficacious treatment of sarcoptic mange on performance and on animal welfare using behavioral indicators and adrenal reactivity testing. Sixteen young cattle with induced sarcoptic mange were allocated by restricted randomization based on body weight to an untreated group (control) or a treated group (eprinomectin 5 mg/mL topical solution [EPRINEX® Pour-On] at Day 0) and monitored for eight weeks after treatment administration (mite counts, lesion scores, anti-Sarcoptes antibodies, feed intake, body weight, 24-hour behavior videotaping, adrenocorticotropic hormone [ACTH] stimulation at Day 58). The treated animals became mite-negative four weeks after treatment while all untreated cattle maintained the infestation. The antibody levels followed the mite counts and lesion scores, decreased after treatment in the treated cattle and increased throughout the study in the untreated controls. Over the 8-week post-treatment period, the treated animals gained more weight (81.9 kg vs. 67.8 kg, respectively; p < 0.05) and had a higher feed conversion efficacy (0.203 kg gain/kg feed vs. 0.154 kg gain/kg feed, respectively; p < 0.01). Behavioral activities of the cattle did not differ between the two groups at Day 0. However, at Day 56 treated cattle spent more time lying during 24 hours (p = 0.0754) and did less often rub, kick and lick (p < 0.05) than the untreated cattle. Analysis of the behaviors of Day 0 vs. Day 56 within each group demonstrated no significant difference for any activity in the untreated group, but extension of lying time and reduction of rubbing, kicking and licking (p < 0.05) were observed for the animals treated eight weeks before. The ACTH stimulation indicated reduced adrenal and systemic reactivity in the untreated cattle. The efficacious treatment of sarcoptic mange resulted in a substantial increase of the performance of the cattle and effectively alleviated the adverse welfare caused by mange. Analysis of specific behavioral activities and adrenal reactivity testing provided evidence for adverse welfare and impacted metabolic capability due to chronic stress caused by the infestation with mange that can be prevented by efficacious treatment.

Investigating the interplay of stressors and health in horses through fecal cortisol metabolite analysis

Introduction

Horses are highly sensitive to stress, which can affect their wellbeing and lead to various health issues. Effective and objective stress assessment is therefore crucial for improving their care and management. The production of the glucocorticoid cortisol is increased in response to stressful stimuli and its metabolites can be measured non-invasively in feces. Therefore, this study aimed to explore the impact of different environmental and physiological stressors on fecal cortisol metabolite (FCM) concentrations in horses, with a particular focus on the relationship between stress, health, and welfare. We hypothesized that increased FCM levels may be indicative of disease and thus improve early detection and subsequent intervention.

Methods

Fresh fecal samples of N = 41 horses (20 geldings and 21 mares) from the same herd were collected once weekly for 1 year. Horses had been housed in the same stable for at least a month and were accustomed to the habitat, daily routine, and social groups. Environmental conditions, health data, and potentially stressful events were recorded. Fecal concentrations of 11,17-dioxoandrostanes were measured via 11-oxoetiocholanolone enzyme immunoassay.

Results

We showed stable baseline FCM concentrations of 6.3 ng/g feces (range 0.6-28.1 ng/g feces). During the summer months, median FCM concentrations increased significantly (p < 0.05; One Way RM ANOVA), and this increase correlated with higher ambient temperatures (p < 0.0001, adj r 2 = 0.669, Pearson Product Moment correlation). Additionally, other factors such as breed, coat color, and housing conditions influenced the FCM concentrations. Stressful events, such as riding exams and some painful conditions, also resulted in elevated FCM levels, although the magnitude of these responses varied across individual horses. However, not all diseases were associated with increased FCMs.

Discussion

Our findings emphasize the complexity of the hypothalamic-pituitary-adrenal axis in horses, suggesting that while high FCM levels can indicate stress, they may not be reliable biomarkers for early disease detection. Particularly in the light of climate change, the impact of heat stress in the summer months should not be neglected and measures to improve the housing conditions accordingly should become an essential part of equine health management.

Hair Cortisol and Fe-BARQ: Evaluating Chronic Stress and Behavior in Cats with Chronic Kidney Disease

This study used hair cortisol concentration (HCC) and the Feline Behavioral Assessment and Research Questionnaire as indicators of chronic stress status and behavioral changes in cats, respectively. Few studies have simultaneously employed both indices to examine cats with chronic kidney disease (CKD). This study aimed to evaluate HCC and questionnaire data from control group cats (n = 21) and those with CKD (n = 21). Additionally, we investigated the correlation between HCC and living environment. For this study, hair samples were collected from the cats' abdomens and analyzed for HCC. Owners completed questionnaires to provide information on their cats' behavior, demographics, environmental factors, and household characteristics over 3 months. Cats in the late-stage CKD group had significantly higher HCC levels than those in the early-stage CKD and control groups. We observed different associations between behavioral patterns, living environments, and HCC depending on the stage of CKD progression. The consistency between the HCC findings and questionnaire results, including the higher HCC levels in the late-stage CKD group and behavioral changes in the CKD group, suggests the possibility of a complex interaction between CKD progression and chronic stress.

Validation of two enzyme immunoassays for non-invasive glucocorticoid measurement in a lacertid lizard (Podarcis muralis): Effects of pharmacological and biological stimuli on faecal corticosterone metabolites and behaviour

The assessment of stress-related hormone levels using non-invasive methods has gained popularity in mammal and bird welfare, yet its application in reptiles remains limited. Particularly, the exploration of physiological measures such as faecal corticosterone metabolites (FCMs) for reptilian welfare has scarcely been explored. This study aims to validate two enzyme immunoassays (5α-pregnane-3ß,11ß,21-triol-20-one and 11-oxoaetiocholanolone EIA) for monitoring FCM levels in the European common wall lizard (Podarcis muralis). We collected daily faecal samples before (baseline) and after (post-treatment phase) inducing elevated corticosterone levels using transdermal administration of corticosterone (pharmacological treatment) and handling/confinement (biological treatment). We also conducted daily behavioural observations to explore the relationship between stress-related corticosterone changes and behaviour. Although treatments induced significant increases in FCM levels, the effect was much larger in the pharmacological one. Transdermal corticosterone induced a cumulative increase in FCMs over the treatment period, with a higher response observed in females. In contrast, the biological treatment yielded smaller FCM peaks, with no significant sex differences. Overall, 5α-pregnane-3ß,11ß,21-triol-20-one EIA appeared to be more sensitive in detecting these effects. Regarding lizard behaviour, both treatments led to increased hiding and decreased basking compared to baseline. The effects were more pronounced in animals subjected to handling/confinement, despite smaller FCM increases. Our results confirm the suitability of an EIA for monitoring FCMs in both male and female common wall lizards and provide insights into the complexities of using integrated approaches to assess stress, highlighting the need for further research on direct measures to evaluate reptile welfare.

Assessment of pig welfare at slaughterhouse level: A systematic review of animal-based indicators suitable for inclusion in monitoring protocols

Pig welfare constitutes a strategic pillar of sustainability within the pork industry. Consequently, there is a need to identify, develop and/or validate indicators for assessing pig wellbeing under commercial conditions. A systematic review following PRISMA guidelines identified 95 pig welfare indicators (PWIs) categorized into physiological, behavioral, health and post-mortem, and product quality. The review evaluated their validity and feasibility (V&F) for use in abattoirs to measure welfare during transport and slaughter. Thirty V&F indicators were found: one physiological (body temperature), 12 behavioral (human-animal relationship, aggression, falling, vocalization, slipping, panting, lying down, sitting, turning back), 13 health and post-mortem (presence of entry points, hernias, body lesions, ear lesions, tail lesions, pericarditis, pneumonia, bursitis, lameness, dead animals, walking and non-walking animals), and four product quality (pH, bruises, body condition, carcass weight). This information might help to identify the factors that affect the risk level of particular pig welfare problems, thereby aiding in the application of risk-based strategies.

Are horned cows in loose housing more stressed than hornless cows? a cross-sectional study in organic dairy farms

In commercial dairy farming, the majority of cows are dehorned or genetically hornless. It is argued that this reduces the risk of injurious and stressful social conflicts. On the other hand, in horned herds, management and housing may be better adapted to the cows, e.g. by avoiding changes in herd structure or by providing more space and resources, which would contribute to reducing stress. This cross-sectional study with 12 horned and 13 hornless organic dairy herds in loose housing aimed to explore the effect of horn status on faecal cortisol metabolites (FCMs) as an indicator for the cows' stress level while taking into account possible differences in the farms' compliance with management and housing recommendations for reducing social conflicts. Repeated faecal samples were collected from 674 cows (n = 2 625 samples), and FCMs were analysed by enzyme immunoassay. A total of 22 housing and management factors relating to guideline recommendations were recorded. Each factor was categorised as compliant, partly compliant, or non-compliant, and percentages of housing, management, and overall compliance were calculated. There was a wide variation in overall compliance between farms, ranging from 20 to 93%. Housing and management compliance correlated positively (rs = 0.62) and farms with horned cows complied with more recommendations (median: 60 vs 48%). A linear mixed model was calculated with the fixed effects of horn status, overall compliance, and their interaction. Cow was nested within herd as a random effect, and days in milk and time of sampling were included as covariates. FCM levels were not higher in horned compared to hornless herds. However, contrary to expectations, no associations with compliance were found. More knowledge is needed about the extent to which FCM levels reflect social stress and whether individual housing or management factors may be particularly important in reducing stress.

Using Faecal Cortisol Metabolites to Assess Adrenocortical Activity in Wild-Living Alpine Marmot Marmota marmota: A Biological Validation Experiment

Faecal cortisol/corticosterone metabolites (FCMs) have become increasingly popular as an easy-to-sample, non-invasive and feedback-free alternative to assess glucocorticoid (GC) levels, key components of the neuroendocrine stress response and other physiological processes. While FCMs can be a powerful aid, for instance, for gaining insights into ecological and evolutionary processes, as well as to assess animal welfare or impacts of anthropogenic stressors on wildlife populations, this method comes with specific challenges. Because GCs are heavily metabolised before excretion, it is critical to validate the enzyme immunoassays (EIAs) used to measure FCMs. Additionally, because species may differ in metabolite profiles, assay validation must be performed separately for each focal species. Despite this, the use of unvalidated assays remains widespread. We performed a biological validation experiment to test a set of EIAs to measure FCMs and adrenocortical activity in free-living Alpine marmots Marmot marmota. We capitalised on capture and handling as part of a relocation project of marmots under the assumption that capture, and handling represent a stressful event and tracked changes in FCM levels over the following 48 h. Faeces samples collected at capture were assumed to return baseline FCM levels. Of the three EIAs tested, only the 11-oxoetiocholanolone '72T' EIA detected an increase in FCM levels about 18 h after capture. This result paves the way for future studies using FCMs to investigate the adrenocortical activity in this species.

Pomegranate as a natural remedy for gastric ulcers prevention: a review of its gastroprotective mechanisms and pharmacological benefits

Gastric ulcers (GUs) represent a common gastrointestinal disorder characterized by mucosal damage and inflammation, often precipitated by factors such as Helicobacter pylori infection and the consumption of COX inhibitors. This comprehensive review investigates the role of oxidative stress and inflammation in the pathogenesis of GUs and assesses the potential therapeutic effects of Punica granatum (pomegranate, Pg) supplementation. Utilizing a series of experimental models, including indomethacin, aspirin, and alcohol-induced ulcers, we demonstrate that Pg extracts possess significant gastroprotective properties. The antioxidant activity of Pg is ascribed to its capacity to neutralize reactive oxygen species (ROS), enhance the activity of endogenous antioxidants such as superoxide dismutase (SOD) and catalase (CAT), and diminish lipid peroxidation. Furthermore, the anti-inflammatory effects of Pg are mediated through the suppression of pro-inflammatory cytokines such as TNF-α and IL-1β, in conjunction with the promotion of gastric mucosal protective agents. Histological analyses indicate that Pg extract preserves the architecture of gastric tissue and alleviates ulcer severity. These findings highlight the potential of Pg as a natural remedy for GUs, thereby necessitating further investigation into its mechanisms of action and optimal therapeutic formulations.

Effects of administering local anesthesia immediately before surgical castration on indicators of pain and discomfort of beef calves

Forty Hereford cross calves (mean and SD of 47.9 ± 10.43 d old) were used to assess the efficacy of lidocaine administered immediately before surgical castration on physiological and behavioral indicators of pain and discomfort. Calves were assigned by age to one of two treatments: surgical castration following subcutaneous injection of 2.5 mL/100 kg body weight of meloxicam (Metacam 20 mg/mL, Boehringer Ingelhein, Burlington, ON, Canada) per kg body weight (MEX, n = 19); or the same treatment preceded 90 s before by a nerve block of the spermatic cord using 8 mL of buffered (1 mL:10 mL of 8.4% sodium bicarbonate USP, Hospira Inc., Lake Forest, IL, USA) lidocaine (4 mL per cord; 20 mg/mL, LIDO-2 with epinephrine, Rafter Products, Calgary, AB, Canada) (LID, n = 21). During the castration procedure, two observers scored how much pain each animal was experiencing (visual analog score, VAS), number of body shakes and leg kicks for each calf. Blood samples and exit scores were collected the day of castration and on d 7, and 14 to assess the neutrophil-to-lymphocyte ratio (N:L) and calf temperament, respectively. Hair samples were collected the day of castration and on d 14 to determine cortisol levels. Scrotal circumference, swelling, and healing scores were determined on d 7 and 14 to assess healing. An accelerometer (HOBO Pendant® G Data Logger, Onset, Cape Cod, MA) was placed on the left hind leg to measure lying behavior until d 6 after castration. Calves were video recorded for 1 hour after the castration procedure to observe behaviors indicative of pain and discomfort. Surveillance cameras were also used to assess the mobility of the calves when cow-calf pairs were moved from the holding pen to the pasture. The VAS, number of tail flicks and foot stamps were greater (P < 0.01) in MEX than in LID calves. During the first hour after castration, LID calves spent more time lying (P = 0.03) and less time standing (P = 0.01) than MEX calves. When moved from the holding pen, LID calves moved faster (P < 0.01) and closer to their dams (P < 0.05) than MEX calves. Hair cortisol was greater (P < 0.05) in LID than MEX calves on d 14. Results suggest that using lidocaine for local anesthesia immediately before surgical castration reduced behaviors indicative of pain and improved mobility post-castration.

Effects of dam fear and stress on metrics of puppy welfare in commercial breeding kennels

It is well established that maternal factors can affect the abilities of offspring to cope with stressors and can influence their overall welfare states. However, maternal effects have not been extensively explored in US commercial breeding kennels (CBKs). Therefore, the objective of this study was to identify if fear and stress in dams affected puppy welfare metrics in CBKs. Bitches (n = 90) were tested at 6 weeks prepartum (6 W Pre), and again with their puppies (n = 390) at 4 (4 W Post) and 8 weeks (8 W Post) postpartum. Dams and puppies underwent stranger approach and isolation tests, and their feces were collected to measure fecal glucocorticoid metabolite (FGM) and secretory immunoglobulin A concentrations. Further, dams' hair cortisol concentrations (HCC) were analyzed at the previously mentioned time points and at 1 week prepartum. Finally, birth and weekly weights were collected from puppies, and litter health metrics were recorded. Data were analyzed using mixed-effects and simple linear regression models. There were significant positive associations between dams' exploration and stationary durations and puppies' durations of the same respective behaviors during the isolation tests (exploration: [Formula: see text]2(1) = 9.472, p = 0.002; stationary: [Formula: see text]2(1) = 5.226, p = 0.022), 8 W Post dam FGMs and 8 W Post puppy FGMs (estimate: 0.0003, SE = 0.0001, p = 0.002), and 4 W Post dam HCCs and 4 W Post litter FGMs (estimate: 0.052, SE = 0.025, p = 0.053). Significant negative associations between 6 W Pre dam HCCs and 8 W Post puppy FGMs (estimate: -0.021, SE = 0.007, p = 0.007), puppies' birth weights ([Formula: see text]2(1) = 3.908, p = 0.048), and puppies' average weekly weight gains ([Formula: see text]2(1) = 0.111, p = 0.739) were also found. These findings suggest that indicators of dam fear and stress may be associated with potential indicators of puppies' welfare states in CBKs. Findings provide new knowledge on fear and stress-related factors that may be used to support the welfare of dams and puppies in CBKs and other populations.

Impact of environmental enrichment on growth, behavior, and welfare of weanling piglets from pre-weaning to 6 weeks of age

The experiment was carried out to study the effect of environmental enrichment before and after weaning on the growth, behaviours, and welfare of weaning pigs. A total of 360 weaning pigs (average initial body weight 6.32 ± 0.10 kg) were randomly allotted to one of the three treatments on the basis of initial body weight. A completely randomized design was used to conduct this study. There were ten pigs per pen, with 6 replicates for each treatment. The experimental treatments were control; WBW-1, play object included one week before weaning/not included; and WBW-2, play object included two weeks before weaning/not included. Weaning pigs raised under environmental enrichment treatments had greater average daily gain and average daily feed intake in phase 1 and greater average daily gain and average daily feed intake in phase 2 and overall than pigs reared in the control group. However, treatment and interaction between treatment and play object installation did not exhibit significant differences. The WBW-1 exhibited a lower body weight coefficient of variation of weaning pigs in phase 1 and phase 2 than weaning pigs that were raised in the control group, however, the interaction between treatment and enriched environment did not show significant differences in phase 1 and 2. The incidence of diarrhea was numerically reduced by enriched environment effect in early phase 1 (d 7) and there were no significant differences in d 14 and d 28. Behaviour traits results showed lower agonistic behaviour, including tail and ear biting by enriched environment effect in phase 1. The enriched environment reduced the skin lesion score in phase 1, however, there were no significant differences in skin lesion score in phase 2. The concentration of hair cortisol was reduced by enriched environment effect at the end of phase 2. These findings suggest that environmental enrichment prior to the weaning process increased growth, group uniformity, and reduced incidence of diarrhea, agonistic behaviour, skin lesions, and concentration of hair cortisol during the post-weaning period. Impact of environmental enrichment on growth, behavior, and welfare of weanling piglets from pre-weaning to 6 weeks of age.

Heat stress affects milk yield, milk quality, and gene expression profiles in mammary cells of Girolando cows

Heat stress during lactation affects the physiological responses, hormonal release, health, and productivity of dairy cows. However, the adverse effects of heat stress on milk synthesis, immune response, and cellular apoptosis in mammary cells remains unknown in Bos indicus cows. This study aimed to understand the relationship between milk yield, milk quality, and the expression of genes related to milk synthesis, cell apoptosis, and immune response in mammary cells of Girolando cows. A total of 24 Girolando cows (3/4 Holstein and 1/4 Gir) were subjected to control (CT; with a temperature-humidity index ranging from 60 to 74, n = 12) or heat stress treatments (HS; with a temperature-humidity index ranging from 60 to 85, n = 12), from 111 to 120 d of lactation. Heat stress significantly increased the expression of heat shock proteins (HSPD1 and HSPD90AA1), insulin receptors (INSR), and prolactin receptor (PRLRsf) genes, and decreased the expression of glucocorticoid receptor (NR3C1) gene in mammary cells of the HS cows when compared with the CT cows. The HS cows exhibited significantly higher vaginal temperatures and cortisol release compared with the CT cows. Moreover, the HS cows had significantly lower DMI and milk yield than CT cows. Although, HS cows showed higher percentage of lymphocytes in milk when compared with that from CT cows. We found no effect of heat stress on other leukocyte counts, somatic cell counts, bacterial counts in milk, or milk composition. Finally, this study demonstrated that Girolando cows are susceptible to heat stress, which decreases milk yield and affects the expression of genes linked to milk synthesis in the mammary cells.

Effects of dietary yeast β-glucan on lactating sows under heat stress

This study sought to determine the impact of dietary supplementation with yeast β-glucan on the alleviation of heat stress (HS) in lactating sows during the summer. Thirty cross-bred sows (Landrace × Yorkshire) with an initial body weight of 216.2 ± 7 kg, an average parity of 3, and their litter were used in this study. Sows were randomly allotted to three treatments (10 sows per treatment). The treatments included the control group (CON), BG5 (supplemented with 0.05% β-glucan and BG10 (supplemented with 0.01% β-glucan). Results showed that yeast β-glucan significantly lowered (p < 0.05) respiratory rate compared to CON, and average daily feed intake was significantly higher (p < 0.05) in the BG10 treatment compared to the CON, although not different from the BG5 treatment. Piglet weaning weight was greater (p < 0.05) in the BG10 group than the CON group although it did not exhibit any distinction from the BG5 treatment, hair cortisol concentration was significantly lowered (p < 0.05) in the BG10 treatment compared to the CON and BG5 treatments, tumor necrosis factor-α was significantly higher (p < 0.05) in the CON treatment than in BG5 and BG10 treatments, the BG10 group demonstrated a significant reduction (p < 0.05) in the. serum level of lipopolysaccharide compared to both the CON and BG5 treatment. Based on these results, dietary yeast β-glucan positively impacted the alleviation of HS in sows, leading to improved average daily feed intake that led to an increase in the growth performance of the litter.

Key Concepts for Enhancing Zoo Animal Welfare: Coping, Comfort, Choice, Control, Challenge, and Compassion

Zoo animal welfare is subject to increasing scrutiny by many audiences. Although zoo husbandry and management techniques have progressed, common welfare issues are still apparent. To encourage further improvements, converting theoretical welfare definition into practical application is key. This paper evaluates a familiar definition to form a baseline for practical welfare assessment that benefits animals and zoo operations. If we consider coping and comfort as measurable indicators, plus choice and control to cement autonomy for the animal, achieving positive welfare is more likely. Providing positive cognitive challenge results in improvements to behavioral diversity. When husbandry is ecologically relevant, this welfare-friendly approach evolves into husbandry-based evidence, further justifying approaches to animal care. The human element of husbandry (e.g., development and training of personnel) impacts on welfare, necessitating a compassionate approach to daily operations. Compassion - for animal and human wellbeing - ultimately embeds welfare as a core zoo goal. The unique environment of the zoo, with its mix of wild species, human workforce and visitors, coupled with the amount we still must learn about species' husbandry needs emphasizes continual development of welfare approaches.

Positive Correlation of Social Rank and Hair Cortisol Concentration in Group-Housed Pregnant Cows

In intensive beef production systems, social dominance relationships among cattle and human-cattle relationships constantly affect cattle welfare. However, these factors have not been investigated to assess their long-term effects on cattle welfare. In this study, the relations of hair cortisol concentrations of group-housed pregnant cows with their social rank and avoidance distance when approached by humans were analysed. Thirty-two Japanese black cows were used in this study. Examinations were conducted six times throughout two years, and each cow was subjected to one-three examinations. Hair sampling was conducted on each examination day. The hair cortisol concentrations were measured using a cortisol enzyme immunoassay kit. Social behaviour recordings were made about 6 h on each examination day. The numbers of occurrences of butt, threat, chase, and avoidance behaviours of each animal were recorded using continuous recording methods, and the social rank score for each animal was calculated from the data. Avoidance distances from humans approaching were measured for 23 test cows during the first three examination days. Measurements were taken 5-10 min after the start of morning feeding. The relations between the hair cortisol concentration and social rank score or avoidance distance were analysed using a mixed-effects model or correlation analysis. Significant positive correlation was found between the social rank score and hair cortisol concentration (F1, 48 = 4.54, p = 0.038). No significant correlation was found between the cows' responsiveness to humans and their hair cortisol concentration (r = -0.004, p = 0.99, n = 23). The findings suggest that low-ranking cows had lower cortisol levels.

Stress Biomarkers in Pigs: Current Insights and Clinical Application

Our study aimed to contribute to the understanding of the stress process in pigs to better assess and control their stress levels. Nowadays, pigs in intensive farming are exposed to several stress factors, such as weaning, transportation, diseases and vaccinations. As a result, the animals experience significant stress responses and inflammatory reactions that affect their health, growth and productivity. Therefore, it is crucial to assess their stress levels, and the use of stress biomarkers could be useful in their evaluation. An up-to-date overview of the different biomarkers that can be used for the assessment of stress is given. It also discusses the methods used to investigate these biomarkers, particularly non-invasive approaches, such as saliva sampling, as practical tools for monitoring animal welfare. In conclusion, our study highlights the importance of using multiple biomarkers for a comprehensive evaluation of stress and points to the need for further research to standardize the sampling procedures and improve stress management in pig farming.

Genetic Variation of Hypothalamic-Pituitary-Adrenal Axis Activity in Farm Animals and Beyond

BACKGROUND

Many experimental data in several species clearly demonstrate the important genetic contribution to variations in HPA axis activity. The influence of corticosteroid hormones on adaptive processes and on production traits such as growth rate, feed efficiency, carcass composition, and meat quality is a strong impetus to the search for the molecular bases of these differences for efficient genetic selection.

SUMMARY

Three main sources of genetic variability have been documented so far in farm animal species, the adrenal cortex sensitivity to ACTH-regulating corticosteroid hormone production, the bioavailability of corticosteroid hormones and especially corticosteroid-binding globulin capacity, and glucocorticoid receptor function. The effect of single mutations may be dependent on the genetic background, and genetic variation of cortisol levels may have different functional consequences depending on the molecular mechanisms responsible for this change.

KEY MESSAGES

Understanding the genetic basis of HPA axis activity allows the development of genomic tools and breeding technologies aimed at improving adaptive capacity and stress tolerance in farm animals and their use as valuable models for the genetic study of the HPA axis and the correlation with adaptation, metabolism, and other functions regulated by adrenal hormones, and associated pathologies (obesity, cardiovascular, etc.). The next step will be to explore HPA axis variability from a system genetics perspective including the multiple sources of variation and their interactions. This multifactorial approach is a prerequisite to the use of the HPA axis phenotypes in the genetic selection for more productive and robust animals, with a high level of production of quality products.

Effect of a Broiler-Specific Light Spectrum on Growth Performance and Adrenocortical Activity in Chickens: A Pilot Study on a Commercial Farm

This study evaluated the effect of a broiler-specific light spectrum on productive performance corticosterone (fCC) and androgen dehydroepiandrosterone (fDHEA) concentrations in feathers, and glucocorticoid (GCMs) and androgen (AMs) metabolites in droppings of broilers. Two groups of female Ross 308 broilers were reared under white LED (WL, n = 9000) and broiler-specific LED (BSL, n = 9000) lights. The body weight (BW) of 150 randomly selected animals/groups was measured weekly. Droppings and feathers were collected at the end of the cycle (29 days) from 20 animals/group. The BSL group showed higher final BW than WL (1407 ± 11 vs. 1341 ± 15 g, respectively; p < 0.001) and higher indices of uniformity (76.8% vs. 61.2% animals in the 10% around the mean, respectively; p < 0.001). No difference between groups was found in fCC and fDHEA concentrations or in the fCC-fDHEA, indicating similar long-term HPA axis activity during the cycle. A higher concentration of GCMs was found in the BSL group, indicating higher glucocorticoid secretion before sampling, with neither a difference in AMs nor in GCMs-AMs. Finally, there was a positive correlation between fCC and fDHEA and between GCMs and AMs (p < 0.01). Our findings suggest that the use of broiler-specific light improved the productivity performances of chickens without long-term consequences on HPA activation. However, the results of this pilot study in a commercial farm setting must be interpreted with caution and need confirmation.

Stress indicators in conservative tissues of Humboldt penguin under captivity

Humboldt penguins (Spheniscus humboldti) from the Barcelona zoo (n=9) were followed to assess their physiological stress status using conservative protocols. Corticosterone levels were measured in feathers and plasma as indicative of chronic and acute physiological stress, respectively. Other markers: B-esterases, potentially indicative of xenobiotic exposure were measured in plasma of these same individuals and reported for the first time in this species. The sensitivity to chemicals of environmental concern, employed as plastic additives, was assessed in vitro with plasma of this species using the inhibition of carboxylesterase (CE) and acetylcholinesterase enzymatic measurements. Among the tested additives, the organophosphorus flame retardants displayed the highest in vitro inhibitory potential on basal CE activity, suggesting their potential utility as biomarkers of this particular chemical class. Additionally, enzymatic measurements in plasma are determined for the first time in Humboldt penguin and can be regarded as baseline values for a potential field monitoring application.

Effects of a Gastroscopic Procedure on Salivary Cortisol Release and Fecal Cortisol Metabolites in Young Racehorses

In this study, gastroscopy was performed twice in 31 two-year-old Thoroughbred racehorses in training. Salivary cortisol (SC) and fecal cortisol metabolite (FCM) concentrations were determined to measure the stress impact. One gastroscopy was performed at the beginning and one six months later at the end of the horses' first training season. According to the Wilcoxon signed rank test, a mild but significant increase of SC (1st gastroscopy: p = 0.0045, 2nd gastroscopy: p < 0.0001) and FCM (1st gastroscopy: p < 0.0001, 2nd gastroscopy: p = 0.0006) values after gastroscopy compared to basal values was detected.

Mechanisms of Heat Stress on Neuroendocrine and Organ Damage and Nutritional Measures of Prevention and Treatment in Poultry

Heat stress (HS) due to high temperatures has adverse effects on poultry, including decreased feed intake, lower feed efficiency, decreased body weight, and higher mortality. There are complex mechanisms behind heat stress in poultry involving the neuroendocrine system, organ damage, and other physiological systems. HS activates endocrine glands, such as the pituitary, adrenal, thyroid, and gonadal, by the action of the hypothalamus and sympathetic nerves, ultimately causing changes in hormone levels: HS leads to increased corticosterone levels, changes in triiodothyronine and thyroxine levels, decreased gonadotropin levels, reduced ovarian function, and the promotion of catecholamine release, which ultimately affects the normal productive performance of poultry. Meanwhile, heat stress also causes damage to the liver, lungs, intestines, and various immune organs, severely impairing organ function in poultry. Nutrient additives to feed are important measures of prevention and treatment, including natural plants and extracts, probiotics, amino acids, and other nutrients, which are effective in alleviating heat stress in poultry. Future studies need to explore the specific mechanisms through which heat stress impacts the neuroendocrine system in poultry and the interrelationships between the axes and organ damage so as to provide an effective theoretical basis for the development of preventive and treatment measures.

Proteomics analysis for key molecules in adrenal glands of Wenchang chickens for their resistance to heat stress

Rising temperatures and intensified agricultural practices have heightened heat stress (HS)-related challenges in poultry farming, notably heat-induced sudden death in chickens. Wenchang chickens, recognized for their heat resistance, have emerged as the potential candidates for improving the economic efficiency of poultry farming. The adrenal gland plays a crucial role in preventing HS-induced heart failure sudden death by secreting hormones. However, little is known about the damage to and resilience of Wenchang chicken adrenal glands during HS. In this study, 34 healthy Wenchang chickens with similar weights were selected for formal experimentation, with 10 as the control group (Con). Following a single exposure to acute HS of 42 ± 1°C and 65% relative humidity for 5 h, 15 deceased individuals formed the HS death (HSD) group, and 9 survived comprised the HS survival (HSS) group. ELISA revealed significant higher (P < 0.05) levels of COR and NE in the HSS and the lowest levels of CORT and EPI in the HSD. Histopathological analysis indicated major degeneration in HSS cortical and chromaffin cells and extensive cell necrosis (nuclear pyknosis) in HSD. Proteomic analysis identified 572 DEPs in HSD vs. Con and 191 DEPs in HSS vs. Con. Bioinformatics highlighted ER protein processing, especially ERAD as a key pathway for heat stress resistance (HSR) in the adrenal gland, with HSPH1, DNAJA1, HSP90AA1, HSPA8 and HERPUD1 identified as regulating key molecules. Western blotting validated significantly higher (P < 0.01) protein levels in both HSS and HSD compared to the Con. Immunohistochemical staining showed increased cytoplasmic HSPH1-positive signal intensity under HS and enhanced HSP90AA1 nuclear signals, strongest in HSS. In summary, HS induces pathological damage in Wenchang chicken adrenal glands, affecting hormone secretion, and various heat shock proteins play crucial roles in cellular resistance. These results elucidate the biological basis of HSR in Wenchang chickens from the perspective of the adrenal gland and provide necessary research foundations for enhancing economic performance of various broilers in high-heat environments and screening drugs for HS treatment.

Assessment of Heat Processing Effects on Cortisol Concentration in Dairy Milk Products

The presence of cortisol residue in processed dairy milk may be a good parameter for assessing the quality of dairy milk products and an alternative indicator of the overall welfare of dairy cattle. Thus, this study investigated the impact of heat processing on milk cortisol concentration (MCC). In total, 36 milk samples (50 mL) were collected from three Holstein dairy cattle at a research farm over two consecutive days. The samples were divided into experimental groups: unheated, heated at 65°C for 30 min, and heated at 121°C for 5 min. Additionally, 11 commercial dairy milk products were purchased under three heating conditions: low temperature, low time (LTLT), ultra-short time (UST), and ultra-high temperature (UHT). MCC was analyzed using an enzyme immunoassay. The average farm MCC (ng/mL) for the unheated milk, milk heated at 65°C, and milk heated at 121°C were 0.88±0.16, 0.86±0.19, and 0.80±0.15, respectively. MCC was not significantly affected by the heating process. The average market MCC (ng/mL) in LTLT, UST, and UHT were 0.16±0.07, 0.15±0.08, and 0.15±0.07, respectively. Overall, cortisol levels in fresh farm milk were unaffected by the heating process. Monitoring cortisol levels in processed milk could offer a valuable alternative indicator for assessing product quality and animal welfare, particularly when access to raw milk is limited.

Effect of organic solvents on earwax cortisol extraction in Hanwoo cattle

Earwax, a semi-solid substance, of both humans and non-human animals contains the stress hormone cortisol. Extraction of cortisol from earwax requires the use of organic solvents to eliminate interference factors. This study aimed to investigate the effects of organic solvents on the extraction efficiency of earwax cortisol from Hanwoo cattle. A factorial arrangement was used to determine the effects of solvent source (methyl alcohol [MA], diethyl ether [DE]) and assay diluent buffer (ADB) (0 and 1 mL) on earwax cortisol concentration (ECC) in Hanwoo cattle (parity 3, body weight = 462 kg). A 25 mg portion of the earwax sample was suspended in ADB, while another 25 mg portion was not suspended prior to extraction with MA and DE. The ECC was measured using a commercial enzyme-linked immunosorbent assay cortisol kit. The results indicated that cortisol can be extracted from earwax with or without ADB. The extraction yield of cortisol from earwax was higher with MA than with DE (p < 0.05). In conclusion, MA is the preferred solvent for cortisol extraction owing to its high extraction yield, simple extraction process, and relatively low solvent consumption. Moreover, earwax cortisol can be used as a biomarker to evaluate the degree of chronic stress in Hanwoo cattle.

Label-free liquid chromatography mass spectrometry analysis of changes in broiler liver proteins under transport stress

Transportation duration and distance are significant concerns for animal welfare, particularly in the poultry industry. However, limited proteomic studies have investigated the impact of transport duration on poultry welfare. In this study, mass spectrometry based bottom up proteomics was employed to sensitively and impartially profile the liver tissue proteome of chickens, addressing the issue of animal stress and welfare in response to transportation before slaughter. The liver exudates obtained from Ross 508 chickens exposed to either short or long road transportation underwent quantitative label-free LC-MS proteomic profiling. This method identified a total of 1,368 proteins, among which 35 were found to be significantly different (p < 0.05) and capable of distinguishing between short and long road transportation conditions. Specifically, 23 proteins exhibited up-regulation in the non stressed group, while 12 proteins showed up-regulation in the stressed group. The proteins identified in this pilot study encompassed those linked to homeostasis and cellular energetic balance, including heat shock proteins and the 5'-nucleotidase domain-containing family. These results contribute to a deeper understanding of the proteome in broiler liver tissues, shedding light on poultry adaptability to transport stress. Furthermore, the identified proteins present potential as biomarkers, suggesting promising approaches to enhance poultry care and management within the industry.

Development of the calf grimace scale for pain and stress assessment in castrated Angus beef calves

Grimace scales have been used to assess pain in various animal species. This study aimed to develop the calf grimace scale (CGS), evaluate its responsiveness and the effect of external factors (change of environment and dam separation, and restraint) on CGS. Sixty-nine Angus calves, 6-8 weeks old, were randomly allocated into castrated (n = 34) and sham castrated (n = 35) groups. Images were extracted from videos pre- (M1-M4), during- (M5), and post-castration/sham castration (M6, M7). Six facial action units (FAUs) were identified: ear position, orbital tightening, tension above the eye, nostril dilation, straining of chewing muscle, and mouth opening. Final CGS median scores increased after castration (P < 0.001) for both non-restrained (M7 versus M2) and restrained (M6 versus M3) calves, indicating scale responsiveness. Final CGS median scores increased (P < 0.001) when calves were subjected to external factors before castration (M1 [baseline] versus M2 and M3). However, there was no difference (P > 0.05) in CGS median scores before and after sham castration, regardless of restraint (M3 versus M6, and M2 versus M7), indicating that the external factors may have reached a maximum effect. The CGS is composed of six FAUs, responsive to acute pain and can identify stress unrelated to pain.

Validation of a Commercial ELISA Kit for Non-Invasive Measurement of Biologically Relevant Changes in Equine Cortisol Concentrations

The measurement of fecal cortisol/corticosterone metabolites (FCMs) is often used to quantify the stress response. The sampling method is relatively non-invasive, reduces concern for elevation of cortisol from the sampling method, and has been shown to measure cortisol more consistently without the daily diurnal rhythm observed in blood. Commercial ELISA (enzyme-linked immunoassay) kits offer benefits over previously validated immunoassay methods but lack validation. The objective of this study was to evaluate a commercial ELISA kit (Arbor AssaysTM DetectX® Cortisol ELISA kit, K003-H1, Ann Arbor, MI, USA) and provide analytical and biologic validation of equine fecal and plasma samples. Horses (4 male, 4 female, mean ± SD: 4 ± 5 yr) were transported for 15 min with limited physical and visual contact via a livestock trailer. Blood and fecal samples were collected pre- and post-transportation. Parallelism, accuracy, and precision tests were used to analytically validate this kit. Data were analyzed using PROC MIXED in SAS 9.4. Plasma cortisol concentrations increased in response to trailering (254.5 ± 26.4 nmol/L, 0 min post-transportation) compared to pre-transportation (142.8 ± 26.4 nmol/L). FCM concentrations increased 24 h post-trailering (10.8 ± 1.7 ng/g) when compared to pre-transportation (7.4 ± 1.7 ng/g). These data support that changes in FCMs can be observed 24 h post-stressor. In conclusion, the Arbor AssaysTM DetectX® Cortisol ELISA kit is a reliable, economic option for the measurement of biologically relevant changes in cortisol in equine plasma and FCMs.

Effects of liquid-based diets with breweries grains enriched with isolated starch and fish oil on veal quality

Since veal production has declined in the U.S., American veal producers are currently making efforts to implement new production standards to improve product quality and animal welfare. In this study, we hypothesized that diets containing brewery grains, starch and omega-3 fatty acids could lower a blood stress indicator and improve meat quality, mostly from a nutritional value stand point. Holstein bull calves with approximately 94.67 ± 12.07 kg of body weight and two months old were randomly assigned to 1 of 3 dietary treatments. Diets were formulated with nonmedicated milk replacer, microbreweries spent grains, and a mineral mix (CONTROL); CONTROL + isolated maize starch (STARCH); and CONTROL +3% fish oil (OMEGA-3). Veal calves fed all three diets were heavier than calves of the same age from experiments reported in the existing literature. Dietary treatments did not affect carcass weights, pH, color, moisture, sensory attributes, volatile profile, and fat quality indexes. Calves fed STARCH and OMEGA-3 showed the lowest levels of blood cortisol. Veal fed CONTROL and OMEGA-3 had higher concentrations of ΣMUFA when compared with STARCH. Veal fed OMEGA-3 had the highest concentrations of EPA, DHA, and Σn-3. Veal from all treatments had very high concentrations of ΣMUFA, mostly driven by high levels of c-9 18:1 n-9 from the milk replacer. Feeding OMEGA-3 lowered blood cortisol and increased levels of EPA and DHA without harming sensory attributes. Overall, including brewery grains, starch and fish oil in liquid diets containing milk replacer can improve veal production.

Effects of Social Group Housing on the Behavioral and Physiological Responses of Captive Sub-Adult Giant Pandas

Wild giant pandas are inherently solitary creatures, however, the ex-situ conservation efforts significantly alter the living circumstances of their captive counterparts. Following the breeding period, giant pandas in captivity may be maintained in social groups. Currently, there is a lack of research on the effects of group housing on the physiology, behavior, and gut microbiota of captive giant pandas. This study divided six captive giant pandas into two groups following the breeding period. By comparing the behavior, physiology, and microorganisms of the two groups, we aim to investigate the behavioral responses and physiological adaptation mechanisms exhibited by captive giant pandas in a "group living" state. Our findings indicate that sub-adult giant pandas housed in group settings exhibit a significantly longer duration of playing behavior (including interactive and non-interactive play) compared to their counterparts housed separately (p < 0.001) while also demonstrating a significantly lower duration of stereotyped behavior than their separately housed counterparts. Additionally, an analysis of urine cortisol and heart rate variability between the two groups revealed no significant differences. Simultaneously, the group housing strategy markedly elevated the β diversity of gut microbiota in sub-adult giant pandas. In conclusion, the group-rearing model during the sub-adult stage has been shown to significantly alter the behavioral patterns of captive giant pandas. In conclusion, within the present captive setting, the group-rearing approach during the sub-adult stage proved to be less distressing for adult captive giant pandas.

Effect of age on amplitude of circulating catecholamine's change of healthy cyclic mares

Catecholamines (CATs) are neurotransmitters and allostatic hormones whose plasma concentrations are physiologically modified in various species such as human, rats, mice and donkeys, with advancing age. However, currently these mechanisms are less well elucidated in horses and more specifically in mares. The hypothesis of this study was that, as in afore mentioned species, the CATs could experience physiological changes with advancing age. The objective of this study was to evaluate the concentrations of adrenaline (A), noradrenaline (NA), dopamine (DA), and serotonin (5-HT) in mares of different ages. Blood samples were drawn from 56 non-pregnant Spanish Purebred mares belonging to four different age groups: 6 to 9 years, 10 to 12 years, 13 to 16 years and > 16 years. The concentrations of A, NA, DA, and 5-HT were determined by competition EIA-Technical 3-CAt EIA, specifically validated for horses. Mares aged > 16 years showed lower A, DA, and 5-HT but higher NA concentrations than 6-9, 10-12, and 13-16 years (p < 0.05). Mares of 13-16 years showed lower A and higher NA than 6-9 and 10-12 years (p < 0.05). A and NA (r=-0.72; p < 0.05), and NA and 5-HT (r=-0.67; p < 0.05) were negatively correlated, and A and 5-HT (r = 0.74; p < 0.05) were positively correlated. Advanced age leads to a predominance of sympathetic nervous activity and lower serotonergic activity in non-pregnant mares.

Effects of weaning and inactivated Lactobacillus helveticus supplementation on dairy calf behavioral and physiological indicators of affective state

The objectives of this study were to determine if weaning would induce behavioral and physiological indicators of a negative affective state, and if supplementation of inactivated Lactobacillus helveticus (ILH) to dairy calves would reduce those indicators of negative affect during weaning. Male Holstein calves (n = 23) were enrolled in the study on d 1 of life. The calves were housed in individual pens in 1 of 4 rooms for the 42 d study. Calves began a stepdown weaning from 9 L/d of milk replacer (MR), at 150 g of MR powder/L, on d 35 and received 6 L/d on d 35 - 36, 3 L/d on d 37 - 38, and 0.4 L/d on d 39 - 42. The MR was divided between 3 meals/d until the last 0.4 L/d phase which was divided between 2 meals/d. Calves had ad libitum water access throughout the study and calf starter from d 28 onwards. Within room, calves were assigned to 1 of 2 treatments: 1) control (CON; n = 11) and 2) 5 g of ILH/d split over and mixed into the 0800 h and 2000 h milk feedings from d 3-42 (ILH; n = 12). Lying behavior was recorded using HOBO data loggers from d 21-41. On d 33, 37 and 41, infrared eye images were taken to determine maximum eye temperature (MET), saliva samples were collected to determine cortisol concentration, and play assessments were conducted to quantify play behavior. On d 34, 38, and 42, blood samples were collected to determine blood serotonin concentration, whereas on d 38 and 39, calves were tested with a cognitive task. A subset of calves (n = 5/treatment) were euthanized to collect gut and brain tissue samples for serotonin concentration on d 43. Weaning resulted in fewer (d 37-41, tendency: d 36), but longer (d 38-41, tendency: d 37), lying bouts and reduced play (d 41), although no changes in lying time, MET, saliva cortisol, nor blood serotonin were detected with initiation of weaning. Supplementation of ILH was associated with lower lying time throughout the study, and reduced play duration and higher salivary cortisol and MET during weaning. No differences in lying bouts, play count, blood and tissue (colon, ileum, prefrontal cortex and brain stem) serotonin concentration, and time to complete the cognitive task were detected between the treatments. Overall, weaning induced behavioral changes indicative of negative affective state, and some behavioral differences were observed with ILH supplementation both before and during weaning, with some physiological changes observed during weaning.

Monitoring the stress physiology of free-ranging mugger crocodiles (Crocodylus palustris) across diverse habitats within Central Gujarat, India

Animals face several challenges in their natural environment, and to cope with such conditions, they may exhibit contrasting physiological responses that directly affect their overall well-being and survival. In this study, we assessed physiological responses via faecal glucocorticoid metabolite (fGCM) measurements in free-ranging mugger crocodiles inhabiting diverse habitats in Gujarat, India. We sampled muggers within Charotar, a rural area (Zone A) with local people having high tolerance towards the presence of muggers, and Vadodara, a region having both urban (Zone B) and rural (Zone C) areas with high levels of human-mugger conflict (HMC). Further, muggers in Vadodara live in water bodies that are mostly polluted due to sewage disposal from adjoining chemical industries. To measure fGCM (mean ± SEM, ng/g dry faeces) levels in muggers, scats were collected during both breeding (N = 107 scats) and non-breeding (N = 22 scats) seasons from all three zones. We used captive muggers (a focal enclosure) to biologically validate (via capture and restraint) the selected fGCM assay (11-oxoetiocholanolone assay). We showed a significant (P < 0.05) 11-fold increase in fGCM levels between pre-capture (540.9 ± 149.2, N = 11) and post-capture (6259.7 ± 1150.5, N = 11) samples. The validated assay was applied to free-ranging muggers during the breeding season, and Zone A showed significantly (P < 0.05) lower fGCM levels (542.03 ± 71.3) compared to muggers of Zone B (1699.9 ± 180.8) and Zone C (1806.4 ± 243.2), both zones having high levels of HMC with polluted water bodies. A similar contrast in fGCM levels was also observed during the non-breeding season. Overall, the study demonstrated that fGCM levels in muggers varied across habitats, and such variation could be due to a multitude of ecological factors that the species experience in their immediate local environment. Moreover, high fGCM levels in muggers of Vadodara during both breeding and non-breeding seasons may indicate a condition of chronic stress, which could be maladaptive for the species.

The clinical importance and correlations of post-partum changes in the clinical findings, reproductive cyclicity, serum-milk oxidant/antioxidant parameters as a stress indicator in female dromedary camel (Camelus dromedarius) and their effect on milk palatability

Dramatic metabolic changes during pregnancy and post-partum period resulted in alteration of the biochemical parameters in dromedary she-camels. The current study focused on assessment of stress indicators in post-partum dromedary she-camels on days 14, 28 and 42 post-calving through monitoring the clinical findings, serum steroid hormones, serum or milk oxidant/antioxidant indicators, and milk somatic cell count (SCC) status with reference to serum lipid profile changes. The study also stated several correlations between reproductive cyclicity parameters, stress biomarkers and serum-milk oxidant/antioxidant indicators. The study was conducted on clinically healthy recently calved she-camels (n = 25). They were subjected to clinical and laboratory assays including lipid profiles, serum steroid hormones [Progesterone (P4) and estradiol (E2)], serum or milk oxidant/antioxidant biomarkers [Malondialdehyde (MDA), reduced glutathione (GSH) and cortisol], and milk SCC on days 14, 21 and 28 post-calving. The study concluded the influence of stress as a result of lactation in post-partum period in recently calved she-camels and its relationship with reproductive cyclicity as well as changes in serum steroids, lipid profiles, serum-milk oxidant/antioxidants parameters, and milk SCC that was reflected through significant elevations in serum levels of P4, E2, cortisol, MDA and glucose, and milk values of MDA, cortisol and SCC as well as significant drop in serum levels of GSH, TPs, albumins and globulins on day 14 post-calving comparing with their values particularly on day 42. The study stated variable correlation relationships between reproductive cyclicity parameters, lipid profiles, serum-milk oxidant/antioxidants parameters and milk SCC.

Peripartal changes of metabolic and hormonal parameters in Romanian spotted cows and their relation with retained fetal membranes

This clinical study investigates various metabolic and physiological parameters in dairy cows during puerperium. Retained fetal membranes (RFM) is a significant postpartum complication that can affect the overall health, fertility and productivity of dairy cattle. The research focuses on changes in total proteins, albumin, glucose, triglycerides, total cholesterol, aspartate aminotransferase (AST) and alanine aminotransferase (ALT), cortisol, insulin, and insulin-like growth factor 1 (IGF-1) levels among cows experiencing normal post-partum period (NP) and those with RFM. A significant increase in protein levels was noted during the post-partum period in the RFM group, indicating physiological impacts of RFM at this stage. Albumin levels showed significant differences, highlighting a significant biological effect of RFM in the post-partum period. Glucose levels varied significantly in the weeks leading to parturition, suggesting altered metabolic states in cows that suffered RFM. Triglyceride and cholesterol levels were significantly higher during the antepartum period in the group that experienced reproductive failure, indicating substantial alterations in lipid metabolism which could herald the apparition of RFM. AST and ALT levels provided insights into cellular stress and liver function, with significant increases noted around parturition which could be attributed to the substantial physiological strain of parturition itself. Cortisol levels were higher in RFM cows 2 weeks before parturition, which could indicate an increasing stress response or a physiological preparation for the upcoming labor, and may be more pronounced in cows predisposed to RFM. Insulin levels decreased significantly before and at parturition in RFM cows, indicating a strong energy deficit. IGF-1 levels decreased significantly in RFM cows after parturition. Significant changes in metabolic parameters, such as glucose, triglycerides, and cholesterol levels, delineate the pronounced metabolic challenges faced by cows with RFM. The study elucidates that while some variations are noted as parturition approaches, the most substantial impacts attributable to RFM on metabolic and physiological parameters occur after parturition. These changes may have implications for the health, recovery, and productivity of cows postpartum, suggesting the need for targeted management strategies to mitigate the effects of RFM.

Do cows with stereotypic tongue-rolling behaviour cope better with their environment?

Introduction

Stereotypic behaviours, especially oral stereotypic behaviours, are frequently expressed in farm animals. Tongue-rolling is the most common oral stereotypic behaviour in dairy cows (Bos taurus). If animals frequently display stereotypic behaviours, this is an indication of poor welfare. It has been suggested that animals express stereotypic behaviours as a way of coping with stress. As a result, animals with stereotypic behaviours may have lower levels of stress hormones than animals without stereotypic behaviours.

Methods

In this study, 916 Holstein cows in the first lactation were subjected to scan sampling behavioural observations 200 times for 10 days. All cows were assigned to either a stereotypic behaviours group (SB) or a control group (CON). The SB group was further subdivided into a tongue-rolling group (TR) and an other-stereotypic behaviours group (OS). The TR group was also split into an only tongue-rolling group (OTR) and a mixed tongue-rolling and other stereotypic behaviours group (TROS). Some cows in the TR group belonged to an extreme tongue-rolling group (ETR). Hair and saliva samples were collected from 601 cows to test cortisol concentrations and dairy herd improvement (DHI) data were collected from a total of 762 cows.

Results

There were no differences in hair or saliva cortisol concentrations between the groups (p>0.05), and the frequencies of tongue-rolling were not associated with cortisol concentrations (p>0.05). For DHI in cows, the milk protein percentage (p = 0.028), milk true protein percentage (p = 0.021) and milk crude protein percentage (p = 0.023) of cows in the ETR group were significantly lower than those in the CON group. For cows in ETR group, as the frequencies of tongue-rolling increased, the milk protein percentage (p = 0.034, r = 0.365), milk true protein percentage (p = 0.022, r = 0.393) and milk crude protein percentage (p = 0.035, r = 0.363) increased.

Discussion

We investigated the relationship between stereotypic behaviours and stress by using a non-invasive sampling method to minimise harm to the cows. We suggest that tongue-rolling may not be a way for cows to cope with stress, at least in terms of cortisol concentrations.

Salivary analysis to unveil the paradigma of stress of domestic horses reared in the wild

Horse welfare is the product of multiple factors, including behavioral and physiological adjustments to cope with stressful situation regarding environment and housing condition. Collectively, it is supposed that a horse kept in the wild has a lower level of stress than other housing system, and the aim of the present study was to investigate the level of stress in domestic horses reared in the wild and then moved to human controlled housing, through saliva analysis. Twelve clinically healthy Catria (Italian local breed) mares, usually reared in the wild, were moved into collective paddocks for a folkloric event. Saliva samples were obtained before and after the change of housing condition to evaluate stress biomarkers including salivary cortisol, salivary alpha-amylase, and butyrylcholinesterase (BChol). The mares were also scored using the Welfare Aggregation and Guidance (WAG) Tool to highlight the presence of abnormal behaviors. Despite the absence of differences in behavioral scores between wild and paddocks, salivary cortisol and BChol were found to be higher in the wild and lower when mares were moved to paddocks. The highest concentrations in stress biomarkers like salivary cortisol and BChol in the wild was unexpected, but the need for managing hierarchical relationships, and the exposure to feral animals, predators, and weather changes, might explain these findings. The overall results of the present study may provide further knowledge toward stress response in domesticated horses living in the wild moved to human controlled housing system.

Randomized comparison between a forced air system and warm water bath for resuscitation of neonatal hypothermic calves with or without oral administration of caffeine

BACKGROUND

Hypothermia is a cause of neonatal calf death in cold climates. Practical and effective rewarming methods are important for bovine health within affected regions.

HYPOTHESIS/OBJECTIVES

To compare the rewarming rate and blood analytes (glucose, lactate, and cortisol) of calves resuscitated with forced air with warm water bath, with or without oral administration of caffeine.

ANIMALS

Twenty healthy neonatal Holstein bull calves.

METHODS

In this randomized, prospective study, calves born healthy and without history of dystocia were cooled to 32°C rectal temperature then thermally resuscitated using either forced air rewarming or warm water bath (40°C) with or without oral administration of caffeine. Rectal temperatures were used to quantify recovery rate. Measurements of glucose, lactate, and cortisol were recorded for every 2°C change in rectal temperature.

RESULTS

Rectal temperature decline (0.03°C per minute) and total cooling time (191.0 ± 33.3 minutes) did not significantly differ among treatment groups. Calves were successfully resuscitated to 38°C by either method. Time required to euthermia using warm water was significantly faster (0.1°C per minute; 64.3 ± 17.8 minute; P < .05) than forced air (0.05°C per minute; 123.1 ± 20.0 minutes). Caffeine had no significant effect on resuscitation rate (P = .14; 95% CI, -0.002 to 0.024) in either treatment; however, caffeine was associated with reduced time to euthermia by 8.3 and 10.8 minutes, respectively. Changes in metabolic variables (glucose, lactate, and cortisol), were inversely related to rectal temperature with no statistical significance among rewarming methods.

CONCLUSIONS AND CLINICAL IMPORTANCE

Although warm water submersion is faster, forced air rewarming is an effective alternative for restoration of euthermia.

Comparison of the Effect of Two Different Handling Conditions at Slaughter in Saliva Analytes in Pigs

In this report, different handling conditions at slaughterhouse were studied to assess changes in salivary biomarkers. For this purpose, finishing pigs were divided into two groups, one in which handling was improved to minimize stress (Group A, n = 24, transported and stabled at the slaughterhouse at low density without mixing with unfamiliar animals throughout the whole process) and another one in which animals had a more stressful handling process (Group B, n = 24, transported and stabled at high density with unfamiliar animals). Saliva samples were taken the day before transport to the slaughterhouse at 8:00 a.m. (B0) and 12:00 a.m. (B4), and the day of slaughter just after unloading animals at the slaughterhouse at approximately 8:00 a.m. (S0) and after 4 h of lairage at approximately 12:00 a.m. (S4). Group B showed significantly higher cortisol, total esterase activity, oxytocin, adenosine deaminase and haptoglobin levels than the Group A at both S0 and S4 sampling times, and higher levels of calprotectin and creatine kinase at S4 sampling time. This report indicates that differences in the way in which the pigs are handled at the slaughterhouse can lead to changes in salivary biomarkers and opens the possibility of the use of biomarker at slaughter to monitor handling conditions.

The Levels of Cortisol and Selected Biochemical Parameters in Red Deer Harvested during Stalking Hunts

As a reactive species, the red deer is sensitive to both negative exogenous and endogenous stimuli. An intensive hunting period may have a particularly negative impact on game animals. The aim of this study was to determine the plasma cortisol level and biochemical parameters in 25 wild red deer (Cervus elaphus) harvested during stalking hunts in correlation with the sex and age of the animals. The mean cortisol concentrations in the stags and hinds analyzed in this study were similar (20.2 and 21.5 ng/mL, respectively). Higher HDL cholesterol values were found in the blood of the hinds than in stags (p < 0.05). Similarly, the mean levels of LDL cholesterol, lactate dehydrogenase, and alanine aminotransferase were higher by 21%, 16%, and 42%, respectively, in the blood of the hinds. In contrast, the levels of alkaline phosphatase, bilirubin, and aspartate aminotransferase were higher in the stags (by 30%, 49%, and 36%, respectively). There was a negative correlation of the cortisol concentration with urea and bilirubin and a positive correlation between cortisol and aspartate aminotransferase in the stags (p < 0.05). In turn, a negative correlation was found between the cortisol and urea levels in the hinds (p < 0.05). In summary, the stress caused by stalking hunts and the characteristic behavior of red deer during the mating season had an impact on chosen biochemical parameters. The increased concentration of cortisol resulted in a decrease in the carcass mass, which may lead to the deterioration of the physical condition of animals on hunting grounds.

Effects of Heat Stress and Lipopolysaccharides on Gene Expression in Chicken Immune Cells

Prolonged exposure to high temperatures and humidity can trigger heat stress in animals, leading to subsequent immune suppression. Lipopolysaccharides (LPSs) act as upstream regulators closely linked to heat stress, contributing to their immunosuppressive effects. After an initial examination of transcriptome sequencing data from individual samples, 48 genes displaying interactions were found to potentially be associated with heat stress. Subsequently, to delve deeper into this association, we gathered chicken bone marrow dendritic cells (BMDCs). We combined heat stress with lipopolysaccharides and utilized a 48 × 48 Fluidigm IFC quantitative microarray to analyze the patterns of gene changes under various treatment conditions. The results of the study revealed that the combination of heat stress and LPSs in a coinfection led to reduced expressions of CRHR1, MEOX1, and MOV10L1. These differentially expressed genes triggered a pro-inflammatory response within cells via the MAPK and IL-17 signaling pathways. This response, in turn, affected the intensity and duration of inflammation when experiencing synergistic stimulation. Therefore, LPSs exacerbate the immunosuppressive effects of heat stress and prolong cellular adaptation to stress. The combination of heat stress and LPS stimulation induced a cellular inflammatory response through pathways involving cAMP, IL-17, MAPK, and others, consequently leading to decreased expression levels of CRHR1, MEOX1, and MOV10L1.

Capturing wild animal welfare: a physiological perspective

Affective states, such as emotions, are presumably widespread across the animal kingdom because of the adaptive advantages they are supposed to confer. However, the study of the affective states of animals has thus far been largely restricted to enhancing the welfare of animals managed by humans in non-natural contexts. Given the diversity of wild animals and the variable conditions they can experience, extending studies on animal affective states to the natural conditions that most animals experience will allow us to broaden and deepen our general understanding of animal welfare. Yet, this same diversity makes examining animal welfare in the wild highly challenging. There is therefore a need for unifying theoretical frameworks and methodological approaches that can guide researchers keen to engage in this promising research area. The aim of this article is to help advance this important research area by highlighting the central relationship between physiology and animal welfare and rectify its apparent oversight, as revealed by the current scientific literature on wild animals. Moreover, this article emphasises the advantages of including physiological markers to assess animal welfare in the wild (e.g. objectivity, comparability, condition range, temporality), as well as their concomitant limitations (e.g. only access to peripheral physiological markers with complex relationships with affective states). Best-practice recommendations (e.g. replication and multifactorial approaches) are also provided to allow physiological markers to be used most effectively and appropriately when assessing the welfare of animals in their natural habitat. This review seeks to provide the foundation for a new and distinct research area with a vast theoretical and applied potential: wild animal welfare physiology.

Screening of heat stress-related biomarkers in chicken serum through label-free quantitative proteomics

Heat stress (HS) can result in sudden death and is one of the most stressful and costly events in chicken. Currently, biomarkers used clinically to detect heat stress state in chickens are not optimal, especially for living ones. Analysis of changes in serum proteins of heat-stressed chickens can help to identify some novel convenient biomarkers for this. Twenty-four chickens were exposed to HS at 42°C ± 1°C with a relative humidity of 65% for continuous 5 h in a single day, and 10 birds were used as controls (Con). During HS, 15 dead chickens were categorized as heat stress death group (HSD), and 9 surviving ones served as heat stress survivor group (HSS). Label-free quantitative proteomics (LFQP) was used to analyze differentially expressed proteins (DEPs) in serum of tested animals. Candidate proteins associated with HS were validated by enzyme-linked immunosorbent assay (ELISA). Diagnostic value of candidate biomarkers was assessed using receiver operating characteristic (ROC) curve analysis. Source of the selected proteins was analyzed in liver tissues with immunohistochemistry and in cell culture supernatant of primary chicken hepatocytes (PCH) using ELISA. In this study, compared to Con, LFQP identified 123 and 53 significantly different serum proteins in HSD and HSS, respectively. Bioinformatics analysis showed that XDH, POSTN, and HSP90 were potential HS biomarkers in tested chickens, which was similar with results from serum ELISAs and immunohistochemistry in liver tissues. The ROC values of 0.793, 0.752, and 0.779 for XDH, POSTN, and HSP90, respectively, permitted the distinction of heat-stressed chickens from the control. Levels of 3 proteins above in the cell culture supernatant of PCH showed an increasing trend as HS time increased. Therefore, considering that mean concentration of POSTN in serum was higher than that of HSP90, XDH, and POSTN may be optimal biomarkers in serum for detecting HS level in chickens, and mainly secreted from hepatocytes. The former indicates that heat-stressed chickens are in a damaged state, and the latter implies that chickens can repair heat stress damage.

Hair cortisol concentration in finishing pigs on commercial farms: variability between pigs, batches, and farms

Hair cortisol is a stress indicator and could be used to assess the pigs' exposure to stressors in the weeks/months prior to non-invasive hair sampling. The main aim of this study was to describe the hair cortisol concentration (HCC) variability between individuals within a batch, between farms and between batches within a farm. The secondary aim was to determine how the number of sampled pigs influences the characterization of HCC within a batch. Twenty farrow-to-finish pig farms were recruited considering the diversity of their management practices and health status (data collected). Hair was sampled in two separate batches, 8 months apart. The necks of 24 finishing pigs were clipped per batch the week prior to slaughter. To describe the variability in HCC, an analysis of the variance model was run with three explanatory variables (batch, farm and their interaction). To identify farm clusters, a principal component analysis followed by a hierarchical clustering was carried out with four active variables (means and standard deviations of the two batches per farm) and 17 supplementary variables (management practices, herd health data). We determined how the number of sampled pigs influenced the characterization of HCC within a batch by selecting subsamples of the results. HCC ranged from 0.4 to 121.6 pg/mg, with a mean of 25.9 ± 16.2 pg/mg. The variability in HCC was mainly explained by differences between pigs (57%), then between farms (24%), between batches within the same farm (16%) and between batches (3%). Three clusters of farms were identified: low homogeneous concentrations (n = 3 farms), heterogeneous concentrations with either higher (n = 7) or lower (n = 10) HCC in batch 2 than in batch 1. The diversity of management practices and health statuses allowed to discuss hypotheses explaining the HCC variations observed. We highlighted the need to sample more than 24 pigs to characterize HCC in a pig batch. HCC differences between batches on six farms suggest sampling pigs in more than one batch to describe the HCC at the farm level. HCC variations described here confirm the need to study its links with exposure of pigs to stressors.

Postpartum hair cortisol, dehydroepiandrosterone sulfate and their ratio in beef cows: Exploring association with parity and conception outcome

Hair steroid measurement has received increasing attention for monitoring hypothalamic-pituitary-adrenal axis function, as it offers the advantages of being noninvasive, fast, and able to indicate steroid concentrations over long periods. The objects of the study were to evaluate cortisol (C) and dehydroepiandrosterone sulfate (DHEA-S) hair concentrations and their ratio (C/DHEA-S) in beef cows from calving to 100 days (d) postpartum (pp) and to assess possible differences related to parity (primiparous vs multiparous) and conception outcome (pregnant vs not pregnant). Hair samples were collected from 6 primiparous and 5 multiparous pregnant beef cows by clipping the coat at calving (T0) and every 20 d for 5 times (T1-T5), collecting only the regrown hair. Starting from the 6th-week pp, cows were submitted to artificial insemination at spontaneous estrus; by 100 d pp, 7 cows were pregnant and 4 were not pregnant. Statistical analysis showed higher hair C concentrations in the 11 cows at calving (T0) compared to all the subsequent samplings except for T1, and higher C concentrations at T1 compared to T3, T4, and T5. These results indicate that hair C concentrations in beef cows are affected by sampling time, with a decrease from calving, as reported in other matrices. When exploring changes within parity groups, no differences were found in the multiparous among sampling times, while hair C concentrations at T0 and T1 tended to be higher than at T2 (0.01 ≤ p < 0.05) and were higher (p < 0.01) than in all the subsequent samplings (T3, T4 and T5) within the primiparous group. Higher hair C concentrations were found at T0 and T1 in the primiparous compared to multiparous (p < 0.01), suggesting that primiparous cows undergo a greater stress level before and around parturition compared to multiparous, probably due to the novelty of the calving experience. No differences were detected in C hair concentrations according to conception outcome (pregnant versus not pregnant) in each sampling time. Hair DHEA-S concentrations were neither affected by time nor by parity or conception outcome. Differences in the C/DHEA-S ratio were found at T1, with higher C/DHEA-S in the multiparous compared to primiparous cows (p < 0.001), and a tendency for higher ratio in the not pregnant compared to the pregnant (0.01 ≤ p < 0.05). These results support the choice of hair as a valuable biological matrix when investigating long-time periods such as postpartum in cows and suggest an enhanced immunoprotective effect of DHEA-S in the postpartum of primiparous cows, and in cows that get pregnant within 100 d postpartum.

Effect of repeated HPA axis stimulation on hair cortisol concentration, growth, and behavior in preweaned dairy cattle

The study objective was to investigate the effect of repeated hypothalamic-pituitary-adrenal (HPA) axis stimulation using synthetic adrenocorticotropic hormone (ACTH) intramuscular injections on hair cortisol concentration, growth, and behavior in preweaned dairy calves. Twenty-seven Holstein calves were assigned to nine triads (based on sex and birth order) and randomly assigned to 1 of 3 treatments: 1) control (CON; 2 mL saline weekly); 2) moderate (MOD; alternating Cosyntropin [2 mcg/kg body weight (BW)] and saline weekly); or 3) frequent (FREQ; Cosyntropin [2 mcg/kg BW] weekly). Calves received their first injection on study day 0 (7 ± 1 d of age). Hair was collected from the tail switch between days -5 and -3 (baseline), 21, and 49 and analyzed for cortisol concentration. To verify the endogenous cortisol release by Cosyntropin during the treatment period, saliva was collected on days 0, 14, 28, and 42 before injection and every 15 min for 2 h after injection for analysis of salivary cortisol concentration. Calves were fitted with accelerometers to continuously monitor lying time, number of lying bouts, and lying bout duration throughout the study. Growth measures (BW, hip height, hip width) were recorded weekly. Data were analyzed using repeated measures ANOVA (SAS, Version 9.4), and models included the fixed effects of treatment, time (min or study day), and interaction between treatment and time. Temperature humidity index was included as a continuous covariate in all models. We observed a treatment × min interaction (P < 0.0001), whereby salivary cortisol concentration was lower in CON calves compared to MOD and FREQ calves 15 to 120 min postinjection. While hair cortisol concentration was not influenced by treatment, concentration decreased from day 21 (1.28 ± 0.03 ng/mL) to 49 (0.93 ± 0.03 ng/mL). Average BW was similar across treatments (CON [59.4 ± 1.09 kg], MOD [58.6 ± 0.98 kg], and FREQ [57.6 ± 0.96 kg]; P = 0.50). There was no evidence to suggest a difference in average daily lying time (CON [18.5 ± 0.23 h/d], MOD [18.6 ± 0.23 h/d], and FREQ [18.5 ± 0.23 h/d]; P = 0.99). These results suggest that repeated HPA axis stimulation through Cosyntropin administration increased salivary cortisol concentration, but did not influence hair cortisol concentration, growth, or behavior in preweaned dairy calves.

Camel filariasis (Dipetalonema evansi) and its association with clinical balanoposthitis with reference to prominent changes in clinical findings, serum testosterone, semen analysis, and testicular histopathology

BACKGROUND

Camel filariasis induced variable clinical syndromes characterized by fever, lethargy, localized dermal lesions, loss of condition, and testicular and scrotal swelling. The objective of the present work focused on clarifying the diagnostic importance of clinical findings, serum testosterone, and semen analysis as well as blood smear and testicular histopathology as a differential tool between only balanoposthitis without filariasis male camels group (OnlyBpgr) and balanoposthitis-filariasis infected male camels group (BpFlgr). The study also monitored the associations between the severity of ticks' infestations in investigated male camels and the occurrence of balanoposthitis only or balanoposthitis with filariasis.

RESULTS AND CONCLUSIONS

The study reported significant correlation between serum testosterone, serum cortisol, and sperm vitality and abnormalities percentages. The study included male camels (n = 250) classified into three groups: healthy control group (Contgr; n = 30), OnlyBpgr (n = 210), and BpFlgr (n = 10). These male camels were clinically and laboratory examined, and skin scraping tests and testicular histopathology were conducted. The study confirmed the association of the changes in clinical findings, whole blood picture, serum testosterone, serum cortisol, and semen analysis, with OnlyBpgr and BpFlgr. These changes were more prominent in BpFlgr than in OnlyBpgr. Skin scraping test results revealed a higher severity of live ticks' infestation in BpFlgr than in OnlyBpgr because, unlike OnlyBpgr, all camels in BpFlgr (n = 10) were suffering from live ticks' infestation. It also concluded the higher efficacy of histopathology of testicular tissues in male camels as a diagnostic tool for adult filaria in balanoposthitis-affected male camels than blood smear because all cases of camel filariasis in the current work were negative for microfilaria on microscopic examination of diurnal blood smear as well as testicular histopathology revealed detection of adult filaria in all camel filariasis associated with balanoposthitis. Strong correlation relationships were demonstrated between serum testosterone, serum cortisol, and semen analysis results. Positive correlations were reported between serum testosterone levels and sperm vitality percentages. However, negative correlations were stated between serum testosterone and each of serum cortisol and sperm abnormalities either in Contgr, OnlyBpgr, or BpFlgr.

Salivary corticosterone reflects plasmatic levels in a wild seabird

Wild animals have been increasingly exposed to a wide range of stressors, mainly due to the intensification of human activities and habitat modifications. Consequently, new tools in order to assess the physiological and health status of wild animals have been developed. In particular, glucocorticoids have received a special attention. Primarily metabolic hormones, they are also used to evaluate the stress level of organisms. While historically measured in blood samples, new less-invasive methods have been recently developed to measure glucocorticoids in matrices such as faeces, hairs/feathers, or saliva. To date, measurements in saliva are still in their infancy despite the numerous advantages of the matrix: non-invasive, reflects the biologically active portion of glucocorticoids, allows to measure both baseline and stress-induced levels. In addition, most studies using saliva have been performed on domestic and captive animals, and recent development in wild animals have focused on mammals. Here, we show, for the first time, that saliva could also be reliably used in free-ranging birds, as glucocorticoid levels in saliva strongly correlated with plasma levels. This promising result opens new avenues for a non-invasive sampling method to assess health status of wild birds in conservation biology and ecology.

Effect of lairage time prior to slaughter on stress in pigs: a path analysis

BACKGROUND

Pre-slaughter process during transportation, handling, and lairage causes stress in pigs, affecting animal welfare and meat quality. Therefore, lairage factors are important for relieving stress. A total of 24 LYD (Landrace × Yorkshire × Duroc) barrows were used to investigate the effect of 6 and 20 h lairage time (LT) on cortisol, serotonin, and catecholamine in blood and physiological factors in muscle, and to verify the causal relationship between these factors.

RESULTS

The results revealed that cortisol was increased (0.064 ± 0.007 µg/ml), and epinephrine (0.020 ± 0.002 µg/ml) and norepinephrine (1.518 ± 0.071 µg/ml) were lower at a LT of 20 h than those at 6 h, and there was no significant effect on the muscle and carcass characteristic factors. In addition, cortisol and norepinephrine showed a negative correlation (r = -50,346, p = 0.0121), epinephrine and glycogen had a positive correlation (r = 0.4417, p = 0.0307), and serotonin and heat shock protein 70 (HSP70) were positively correlated (r = 0.4715, p = 0.0200). Path analysis indicated that the increase in LT had a direct effect on cortisol, epinephrine, and norepinephrine, and an indirect effect on muscle glycogen.

CONCLUSION

This study confirmed the effect of the increase in LT from 6 to 20 h in the lairage room on the stress response of pigs. These findings support the legal requirements that advocate for shorter lairage times, in alignment with enhanced animal welfare standards.

Physiological response of roe deer (Capreolus capreolus) during stalking hunts depending on age

BACKGROUND

The European roe deer (Capreolus capreolus) is a species particularly reactive to all kinds of negative stimuli. Hunting activity is one of the most potent stressors that disturbs the welfare of wild animals. During stress, various endocrine responses are elicited to improve the physical performance of the affected individual. A commonly assessed hormone for overcoming stressful situations is cortisol (CORT). In this study, plasma CORT levels in roe deer were assessed during the season of the most intense stalking hunts in Poland (summer vs. late autumn), the sex of the harvested animals (males vs. females), and age of harvest animal. In addition, the health status of the roe doe was evaluated on the basis of selected indices of blood chemistry, which could be associated with circulating cortisol levels.

RESULTS

The mean cortisol levels were 58.066 ng/ml in the male group (summer) and 27.694 ng/ml in the female group (late autumn). Higher CORT levels were associated with a significantly lower of total cholesterol, lactate dehydrogenase, and uric acid (p < 0.05). Moreover, the mean concentration of uric acid was negatively correlated with the level of CORT in the male and female groups (p < 0.05). Together with the increase in mean CORT level, the HDL cholesterol of all the tested animals increased significantly (p < 0.05).

CONCLUSIONS

Higher CORT in males during the summer than in females during the late autumn were most likely due to the arousal with the mating season. The level of CORT increased with the animals' age. Uric acid and age are both predictors of roe deer's serum CORT level.