Stress during the transition of beef steers from ranch to feedlot may depend on steer source and preconditioning. The interplay between physiological and behavioural patterns of preconditioned (PC) and auction-derived (AD) steers, particularly after commingling, is poorly understood. Our objective was to evaluate whether hair cortisol (HC) concentrations were related to the health and performance of PC and AD steers and study behavioural activities after commingling over six weeks in a feedlot. Steers, sourced either from ranch (PC, n = 250) or local auction (AD, n = 250), were assigned into 1 of 5 pens, 100% PC (100PC); 75% PC 25% AD (75PC); 50% PC 50% AD (50PC); 25% PC 75% AD (25PC), and 100% AD (0PC), each pen containing 100 steers. Pen was the experimental unit and individual steers were the observational unit where physiological and behavioural changes were measured. The study subsampled 225 steers (PC = 113 and AD = 112) which were equipped with CowManager ear tags to record behavious. On day 40, hair samples from each steer were collected by clipping hair close to the skin. Data were analyzed using multiple linear, logistic regression, or multilevel negative binomial regression models depending on the outcomes. There was no difference in HC concentrations (Day 40) between PC and AD steers (P = 0.66), and no association with Bovine Respiratory Disease (BRD)-related morbidity (P = 0.08) or average daily gain (ADG) (P = 0.44). After adjusting for source and commingling effects, HC concentrations did not affect time spent eating (P = 0.83), ruminating (P = 0.20), active (P = 0.89), or non-active (P = 0.32). PC steers spent more time eating and ruminating over Weeks 1 to 4 (P < 0.01) and Weeks 1 to 3 respectively (P < 0.05), and more time being active over Weeks 1 and 2 compared to AD steers (P < 0.001), but less time being non-active than AD steers on Weeks 1 to 3 (P < 0.001). Steers in 100PC and 50PC pens spent more time eating than steers in 0PC (P < 0.001), whereas steers in 25PC spent less time eating than steers in 0PC (P < 0.001). Steers in 0PC spent the most time being not active (P < 0.01). In conclusion, preconditioned steers spent more time eating, ruminating, and being active and less time being not active over the first three weeks in the feedlot, regardless of commingling. The HC concentrations did not identify potentially lower stress related to ranch transfer and were neither associated with BRD-related morbidity nor ADG.

Postpartum depression and depressive symptoms have a major impact on maternal and infant health and well-being, yet to date their aetiology remains unclear. One hypothesis suggests a link between these symptoms and variations in prenatal cortisol levels, but existing evidence is limited and inconclusive. This study aims to provide additional evidence to disentangle the relationship between prenatal cortisol concentrations and subsequent occurrence of postpartum depressive symptoms. Cortisol for all three trimesters of pregnancy was extracted from the hair of 775 women participating in the French ELFE cohort. Depressive symptomatology at two months postpartum was assessed through the Edinburgh Postpartum Depression Scale (EPDS). Associations between prenatal cortisol levels and EPDS scores were tested using propensity-score weighted logistic regression models to control for confounders. An increase in mean cortisol concentrations was observed from the first to the third trimester of pregnancy. No significant differences in hair cortisol concentrations were found during the first and second trimesters between women who experienced postpartum depressive symptoms and those who did not. However, an association was observed between third trimester hair cortisol concentrations and depressive symptoms at two months postpartum. Women whose cortisol concentrations fell within the second quartile had a higher risk of subsequent PPDS (aOR = 2.67, 95%CI [1.01, 7.08]). Using a large sample from the general population, we observed an association between hair cortisol levels during the third trimester of pregnancy and postpartum depressive symptoms. Nevertheless, our results suggest that future studies could benefit from investigating other biomarkers of the reactivity of the corticotropic axis.

BACKGROUND: Hair cortisol concentration (HCC) is a biomarker of long-term stress. Higher HCC is associated with higher adiposity in adults; however, associations are not well characterized in adolescents.
OBJECTIVE: To examine cross-sectional associations of HCC with adiposity in late adolescence.
METHODS: Amongst 336 non-Hispanic White participants (48.5% female, mean 17.7 years) in Project Viva, we used multivariable linear regression models, overall and sex-stratified, to estimate associations of HCC with body mass index (BMI), bioelectric impedance (BIA) percent body fat, waist circumference (WC) and dual X-ray absorptiometry-measured percent and total fat or trunk fat mass. We adjusted models for age and known predictors of adiposity.
RESULTS: Median (interquartile range) HCC was 2.1 pm/mg (1.0-4.5) and mean (SD) BMI was 23.1 kg/m2 (3.9), BIA %body fat 20.2% (9.9) and WC 80.6 cm (10.9). In adjusted models, higher HCC (per doubling) was associated with higher BMI (β = 0.19 kg/m2; 95%CI 0.00, 0.37) and BIA percent body fat (β = 0.41%; 95%CI 0.04, 0.77). We observed no evidence of effect modification by sex.
CONCLUSIONS: Higher HCC was associated with greater adiposity in late adolescence. Further research is needed to disentangle the relationship between HCC and adolescent adiposity, including the temporal direction of the relationship and sex-specific associations.

Human hair cortisol concentration (HCC) has previously been found to be highly stable for a 1-year interval (r = 0.73) in terms of a product-moment correlation. The present study aimed to replicate this finding and compare HCC stability regarding 1-year and 2-year test-retest intervals. Female university students (N = 39) provided hair strands twice (t1 and t2) at intervals of 1 (n = 21) or 2 years (n = 18). Multiple regression analysis predicting HCC at t2 revealed a significant interaction term (HCC at t1 × time interval condition). It was determined that HCCs were substantially related for the 1-year interval but unrelated for the 2-year interval. The findings were not attributable to potential influences, such as hair treatment. The product-moment correlation showed nearly identical consistency with previous research regarding the 1-year test-retest interval. There was no significant product-moment correlation for the 2-year interval. Overall, these findings indicate that within a temporal framework of 1 year, HCCs may be stable predictors in correlational studies where the focus is on the rank orders of measured values.

BACKGROUND: Cortisol is a biological marker of stress, and its levels reflect the hypothalamic-pituitary-adrenal (HPA) axis response to stress over time. Saliva, blood, and urine cortisol reflect acute stress, whereas assessment of hair cortisol is a better reflection of chronic stress. There is limited information on hair cortisol concentration (HCC) in the perinatal period, particularly, in the preconception and postpartum periods. In addition to being a biomarker for stress, high levels of cortisol are typically associated with poor psychosocial outcomes, and adverse pregnancy outcomes. The objectives of this study were: (1) to measure HCC from six months preconception to six months postpartum; (2) to examine the relationship between HCC and demographic characteristics, depressive symptoms, and perceived stress in the first six months postpartum period; (3) and to assess the associations between HCC and systemic inflammatory markers in the first six months postpartum.
METHODS: The analysis included 96 women from a longitudinal study with up to 3 study visits in the first six months postpartum. Blood and hair samples were collected at 1-2 months (PP1), 3-4 months (PP2), and 5-6 months (PP3) postpartum. We obtained sociodemographic information, depressive symptoms, and perceived stress scores at PP1-PP3. To quantify cortisol levels over time, 8 segments were derived corresponding to 6 (PC1) and 3 (PC2) months preconception as well as for each trimester (T1-T3) and postpartum (PP1-PP3). Eight cytokines (Granulocyte-macrophage colony-stimulating factor (GM-CSF), Interferon- gamma [IFN- γ], Interleukin [IL]-10, IL-2, IL-4, IL-6, IL-8, and Tumor necrosis factor-alpha (TNF- α) were measured in plasma in the postpartum samples. Univariate, bivariate, correlations, and linear mixed modelling were performed using SAS 9.4. Multiple testing correction was conducted for correlations using false discovery rate and a Q value of <0.05 was deemed significant.
RESULTS: Median HCC varied over time peaking in the third trimester and declining in the postpartum. Significant differences were noted in median cortisol levels by race with Black/African American postpartum women experiencing higher levels at all timepoints. Significantly, higher median cortisol levels were also observed at PP1 and PP2 for mothers who reported their relationship status as single. Ethnicity, education, median age, depressive symptoms, and perceived stress were not associated with median cortisol levels. Pro-inflammatory cytokines IFN- γ (q= 0.01; r=-0.50) and IL-8 (q= 0.00; r=-0.55) showed correlations with HCC at PP1.
CONCLUSIONS: HCC increased during pregnancy, peaking at T3 and declining PP consistent with previous work. Black/African American women and single women have significantly higher median cortisol levels in the postpartum period. The marked increase of HCC in Black women may be an important factor in understanding maternal health racial inequities. Future studies should investigate how the relationships between HCC, sociodemographics, and systemic cytokines impact perinatal outcomes.

UNASSIGNED: Most studies assessing hair cortisol were conducted with adults. As specific guidelines for infant hair collection are lacking, we developed a hair collection protocol for 12-month-old infants and assessed its acceptability and feasibility.
UNASSIGNED: Out of the total (N = 45), 95.6 % (n = 43) of caregivers consented to the procedure, while one caregiver did not consent (2.2 %), and another requested the procedure to be halted before required amount of hair had been reached (2.2 %). Furthermore, two (4.4 %) infants did not have enough hair for collection. There was no attrition due to infant fussiness/crying.
UNASSIGNED: We learned five lessons which can help to enhance reproducibility, mother\'s consent, and mother-infant comfort and acceptance of the procedure. The first lesson is to have the infant sit on the caregiver\'s lap to ensure the infant feels safe and remains relatively still. The second is to reassure caregivers by showing hair samples representing the amount to be cut as well as by clarifying no unaesthetic gaps would be visible. The third is to caress the infant\'s head to habituate them to the hair manipulation and to make soap bubbles as distractors. The fourth is to take extra care when securing the lock of hair for cutting because the infant scalp is thin and malleable. The fifth is to place a precision scale in the collection room to ensure the necessary weight is reached.
UNASSIGNED: Our hair collection protocol developed for 12-month-old infants was deemed feasible and acceptable, filled an important literature gap concerning the absence of published protocols for infants, and will contribute to increase the replicability and collection efficiency for other research teams.

OBJECTIVE: Partners of breast cancer (BC) survivors report high rates of psychological distress including fear of cancer recurrence (FCR). Research suggests that partners may have poorer physical health outcomes than the general population, but little research has examined the physiological biomarkers by which distress may impact partner health outcomes. The current study examined the associations between FCR and changes in hair cortisol among BC partners.
METHODS: Male partners (N = 73) of early-stage BC survivors provided hair samples during two visits, one after completion of survivors\' adjuvant treatment (T1) and again 6 months later (T2). Two subscales from the Fear of Cancer Recurrence Inventory and one subscale from the Concerns about Recurrence Scale comprised a latent FCR factor at T1. A latent change score model was used to examine change in cortisol as a function of FCR.
RESULTS: Partners were on average 59.65 years of age (SD = 10.53) and non-Hispanic White (83%). Latent FCR at T1 was positively associated (b = 0.08, SE = 0.03, p = .004, standardized β = .45) with change in latent hair cortisol from T1 to T2.
CONCLUSIONS: Results indicated that greater FCR was associated with increases in hair cortisol in the months following adjuvant treatment. This is one of the first studies to examine the physiological correlates of FCR that may impact health outcomes in BC partners.
CONCLUSIONS: Findings highlight the need for further research into the relationship between FCR and its physiological consequences. Interventions to address partner FCR are needed and may aid in improving downstream physical health outcomes.

BACKGROUND: Substance use is highly prevalent among women experiencing intimate partner violence (IPV) and has been associated with dysfunction of the hypothalamic-pituitary-adrenal (HPA) axis and resulting cortisol response. Posttraumatic stress disorder (PTSD) symptoms may play an important role in exacerbating the association between cortisol levels and substance use behaviors.
OBJECTIVE: This study examined the role of PTSD symptoms in the relation between cortisol and past month substance use behaviors. The current study used hair cortisol as an index of past 30-day HPA-axis functioning and ecological momentary assessment (EMA) to characterize substance use behaviors more accurately over a 30-day period.
METHODS: Participants were 90 community women who had experienced physical or sexual IPV in the past 30 days by their current male partner and used any amount of alcohol or drugs (M age = 40.71; 54.4 % white). Participants completed (a) a baseline interview, (b) EMA for 30-days, and (c) a follow up interview where they were asked to provide a hair sample for cortisol analyses. Data collection took place from 2018 to 2020.
RESULTS: PTSD severity moderated the relations between cortisol and days of drinking and binge drinking. In the context of high PTSD symptomology, women with high cortisol levels spent, on average, an additional 7.4 days drinking and 8.1 days binge drinking in the past 30 days compared to women with low cortisol levels, in a model adjusted for age.
CONCLUSIONS: Results highlight the prominent role of PTSD symptoms in the association between cortisol and alcohol use among women experiencing IPV.

Although neighborhood contexts serve as upstream determinants of health, it remains unclear how these contexts \"get under the skin\" of Mexican-origin youth, who are disproportionately concentrated in highly disadvantaged yet co-ethnic neighborhoods. The current study examines the associations between household and neighborhood socioeconomic status (SES), neighborhood racial-ethnic and immigrant composition, and hair cortisol concentration (HCC)-a physiological index of chronic stress response-among Mexican-origin adolescents from low-income immigrant families in the United States. A total of 297 (54.20% female; mage = 17.61, SD = 0.93) Mexican-origin adolescents had their hair cortisol collected, and their residential addresses were geocoded and merged with the American Community Survey. Neighborhoods with higher Hispanic-origin and foreign-born residents were associated with higher neighborhood disadvantage, whereas neighborhoods with higher non-Hispanic White and domestic-born residents were associated with higher neighborhood affluence. Mexican-origin adolescents living in neighborhoods with a higher proportion of Hispanic-origin residents showed lower levels of HCC, consistent with the role of the ethnic enclave. In contrast, adolescents living in more affluent neighborhoods showed higher levels of HCC, possibly reflecting a physiological toll. No association was found between household SES and HCC. Our findings underscore the importance of taking sociocultural contexts and person-environment fit into consideration when understanding how neighborhoods influence adolescents\' stress physiology.

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.
Measures to quantify long-term or chronic stress in livestock are limited. The amount of cortisol (a stress hormone) deposited in the hair has been used as a noninvasive measure of long-term stress in some livestock species; however, few studies have investigated its use in young dairy calves. The objective of this study was to determine the efficacy of hair cortisol as a less invasive measure of stress in calves. Calves were either injected with saline (control) or Cosyntropin, a hormone that activates the stress response system, at different frequencies during the first two months of life. Cosyntropin injection increased salivary cortisol concentration (an indicator of acute stress) but did not increase hair cortisol concentration. There was no evidence to suggest a significant effect of treatment on calf growth. Calf behavior was similar between treatment groups. These results suggest that the method used to activate the stress response system in this study was sufficient to induce an acute stress response in calves (as indicated by increased salivary cortisol concentration), and more research is needed to investigate measures of chronic stress in young dairy calves.