Relationship between periparturient diseases, metabolic markers and the dynamics of hair cortisol concentrations in dairy cows.

Hair cortisol concentration (HCC) might represent a promising marker for retrospective welfare assessment of dairy cows. The objective of the study was to explore the dynamics of HCC in diseased and healthy cows from eight-week ante partum (AP) to eight-week post partum (PP). Twenty-four pregnant cows were followed from drying off to week eight PP. Tail hair was used to measure cortisol at five different time points. The occurrence of peripartum diseases, lameness and the body condition score (BCS) were monitored on a weekly basis. Blood ß-hydroxybutyric acid, non-esterified fatty acids, calcium and insulin-like growth factor-1 (IGF-1) concentrations were measured. The temperature-humidity index (THI) was continuously recorded. The median values of HCC in all cows were 0.4, 0.3, 0.6, 0.8 and 0.5 pg/mg at weeks eight, four AP, calving, weeks four, eight PP, respectively. There was no association between HCC and the occurrence of peripartum diseases (P ≥ 0.05). A positive correlation between HCC and BCS loss (P < 0.01) and THI (P < 0.05) was observed. The occurrence of peripartum diseases was associated with low IGF-1 during the study period but no relationship was found between cortisol and IGF-1 levels (P ≥ 0.05). Brown Swiss cows showed higher HCC (P < 0.01) at weeks eight, four AP, and week four PP and lower average milk yield (P < 0.05) than Holstein-Friesian cows. In conclusion, HCC was not a suitable marker for peripartum diseases but it could reflect a stress response, which is linked to BCS loss, heat stress and breed.

Hair cortisol concentrations in bovine neonates born to healthy and ill cows.

INTRODUCTION: The goal of this study was to investigate the hair cortisol concentration (HCC) in healthy and ill cows and their newborn calves. A total of 40 cows and their 42 newborn calves were divided into two groups: group 1 consisted of 19 clinically healthy cows and their 20 newborn calves, and group 2 comprised 21 cows that had had a chronic illness in the third trimester of gestation and their 22 newborn calves. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) system was used to measure the HCC in hair samples that were collected from the cows and calves on the day the calves were born. In both groups, the mean HCCs of the calves was significantly higher than that of the cows (group 1, 31,0 vs. 0,6 pg/mg; group 2, 19,4 vs. 0,8 pg/mg; P.

INTRODUCTION: Le but de cette étude était d'étudier la concentration de cortisol dans les poils (HCC) chez des vaches saines et malades et chez leurs veaux nouveau-nés. Un total de 40 vaches et leurs 42 veaux nouveau-nés ont été divisés en deux groupes: le groupe 1 comprenait 19 vaches cliniquement saines et leurs 20 veaux nouveau-nés, et le groupe 2 comprenait 21 vaches ayant eu une maladie chronique au cours du troisième trimestre de gestation et leurs 22 veaux nouveau-nés. Un système de chromatographie liquide avec spectrométrie de masse en tandem (LC-MS/MS) a été utilisé pour mesurer le HCC dans des échantillons de poils prélevés sur les vaches et les veaux le jour de leur naissance. Dans les deux groupes, le HCC moyen des veaux était significativement plus élevé que celui des vaches (groupe 1, 31,0 pg/mg contre 0,6 pg/mg ; groupe 2, 19,4 pg/mg contre 0,8 pg/mg ; P.

Hair cortisol concentrations in different breeds of cows: Comparison of hair from unshorn and previously shorn areas and from various regions of the body.

INTRODUCTION: The goals of this study were to investigate hair cortisol concentration (HCC) in seven different breeds of cows, to establish reference intervals for HCC in Brown Swiss cows and to compare cortisol concentrations of hair collected from four different areas of the body. Three groups of cows were used. Group 1 comprised 70 healthy cows representing four dairy breeds (Brown Swiss, Swiss Fleckvieh, Holstein Friesian, Water Buffalo) and three beef breeds (Raetian Grey, Limousin, Highland). Group 2 consisted of 60 healthy Brown Swiss cows in which two different hair samples were collected from the thoracic region to establish reference intervals; A samples consisted of hair that had grown for one month in a pre-clipped area, and B samples consisted of hair from a previously unshorn area. Group 3 comprised 21 healthy Brown Swiss cows, in which HCCs were measured in A and B samples from four different body regions (neck, shoulder, thorax, rump). Liquid chromatography tandem mass-spectrometry was used for cortisol measurement. In group 1, the highest HCCs were measured in Holstein Friesian cows at 1,75 pg/mg, which was significantly higher than those of the Brown Swiss, the Swiss Fleckvieh and the Water Buffalo cows. Hair cortisol concentration and daily milk yield of the 40 dairy cows were highly correlated (r = 0,57, P < 0,01). In group 2, the HCCs of 77 % of the A samples and 85 % of the B samp-les were below the laboratory's limit of quantification (LOQ) of 0,50 pg/mg and the results were expressed semiquantitatively as.

INTRODUCTION: Les objectifs de cette étude étaient d'étudier la concentration de cortisol dans les poils (hair cortisol concentration (HCC)) chez sept races de vaches différentes, d'établir des intervalles de référence pour le HCC chez les vaches de race Suisse Brune et de comparer les concentrations de cortisol dans les poils prélevés sur quatre zones différentes du corps. Trois groupes de vaches ont été utilisés. Le groupe 1 comprenait 70 vaches saines représentant quatre races laitières (Brown Swiss, Swiss Fleckvieh, Holstein Friesian, Buffle d'eau) et trois races à viande (Grise rhétique, Limousin, Highland). Le groupe 2 était composé de 60 vaches Brown Swiss en bonne santé, pour lesquelles deux échantillons de poils différents ont été prélevés dans la région thoracique afin d'établir des intervalles de référence ; les échantillons A étaient constitués de poils ayant poussé pendant un mois sur une zone précédemment tondue et les échantillons B étaient constitués de poils provenant d'une zone non tondue auparavant. Le groupe 3 comprenait 21 vaches suisses brunes en bonne santé, chez lesquelles les HCC ont été mesurés dans des échantillons A et B provenant de quatre régions corporelles différentes (cou, épaule, thorax, croupe). La chromatographie liquide en tandem avec spectrométrie de masse a été utilisée pour la mesure du cortisol. Dans le groupe 1, les HCC les plus élevés ont été mesurés chez les vaches Holstein Friesian à 1,75 pg/mg, ce qui était significativement plus élevé que ceux des vaches Brown Swiss, Swiss Fleckvieh et Buffle d'eau. La concentration de cortisol dans les poils et le rendement laitier quotidien des 40 vaches laitières étaient fortement corrélés (r = 0,57, P < 0,01). Dans le groupe 2, les HCC étaient inférieures à la limite de quantification (LOQ) de 0,50 pg/mg dans 77 % des échantillons A et 85 % des échantillons B et ils ont été indiquées de manière semi-quantitative comme < LOQ. Dans les échantillons restants, les HCC se situaient entre 0,50 et 1,20 pg/mg. Les valeurs des échantillons A et B n'étaient pas significativement différentes. Dans le groupe 3, les valeurs médianes des HCC des échantillons mesurables pour les 4 localisations se situaient entre 0,50 et 1,00 pg/mg de poils. Les HCC ne différaient pas significativement entre les différentes localisations corporelles ni entre les échantillons A et B. Les analyses permettent de supposer que les vaches Holstein-Friesian présentent des HCC significativement plus élevées que les vaches Brown Swiss, Swiss Fleckvieh et les bufflonnes d'eau et que cela est dû au moins en partie à leur production laitière élevée.

Nocturnal Gamma-Hydroxybutyrate Reduces Cortisol-Awakening Response and Morning Kynurenine Pathway Metabolites in Healthy Volunteers.

BACKGROUND: Gamma-hydroxybutyrate (GHB; or sodium oxybate) is an endogenous GHB-/gamma-aminobutyric acid B receptor agonist. It is approved for application in narcolepsy and has been proposed for the potential treatment of Alzheimer's disease, Parkinson's disease, fibromyalgia, and depression, all of which involve neuro-immunological processes. Tryptophan catabolites (TRYCATs), the cortisol-awakening response (CAR), and brain-derived neurotrophic factor (BDNF) have been suggested as peripheral biomarkers of neuropsychiatric disorders. GHB has been shown to induce a delayed reduction of T helper and natural killer cell counts and alter basal cortisol levels, but GHB's effects on TRYCATs, CAR, and BDNF are unknown. METHODS: Therefore, TRYCAT and BDNF serum levels, as well as CAR and the affective state (Positive and Negative Affect Schedule [PANAS]) were measured in the morning after a single nocturnal dose of GHB (50 mg/kg body weight) in 20 healthy male volunteers in a placebo-controlled, balanced, randomized, double-blind, cross-over design. RESULTS: In the morning after nocturnal GHB administration, the TRYCATs indolelactic acid, kynurenine, kynurenic acid, 3-hydroxykynurenine, and quinolinic acid; the 3-hydroxykynurenine to kynurenic acid ratio; and the CAR were significantly reduced (P < 0.05-0.001, Benjamini-Hochberg corrected). The quinolinic acid to kynurenic acid ratio was reduced by trend. Serotonin, tryptophan, and BDNF levels, as well as PANAS scores in the morning, remained unchanged after a nocturnal GHB challenge. CONCLUSIONS: GHB has post-acute effects on peripheral biomarkers of neuropsychiatric disorders, which might be a model to explain some of its therapeutic effects in disorders involving neuro-immunological pathologies. This study was registered at ClinicalTrials.gov as NCT02342366.

Endogenous cortisol in keratinized matrices: Systematic determination of baseline cortisol levels in hair and the influence of sex, age and hair color.

The measurement of hair cortisol is increasingly used to measure long-term cumulative cortisol levels and investigate its role as an important stress mediator. In this study a comparative statistical analysis of five independent studies (all analyzed in our laboratory) was performed to investigate baseline ranges of cortisol values in hair and evaluate potential influences of sex, age and hair color. Cortisol concentrations in hair of 554 subjects were measured and a comparative statistical analysis was performed. The analysis showed that cortisol levels significantly differ depending on age. The toddler group (7 months (0.6 years) to 3 years) showed significantly higher values (median 10pg/mg, p-value<0.0001, d=0.78) than the adolescent group. The adolescent groups showed significantly lower (p-value<0.0001, d=0.58 and p<0.0001, d=0.13) values (median 2.4pg/mg and 2.8pg/mg) than the adult group (median 5.8pg/mg). Furthermore, in the adult group men showed significantly higher cortisol values than women (p-value<0.05, d=0.17). This effect could not be seen in the adolescent group. Black hair showed higher cortisol concentrations than blond hair (p-value<0.0001, d=1.3). In addition, two rounds of interlaboratory comparisons for hair cortisol samples between four laboratories revealed very consistent results. Our results demonstrate that baseline cortisol levels are generally low in hair thus making a standardized and well-elaborated analytical method indispensable for accurate determination. Age-dependent normative baseline cortisol levels (toddlers, adolescents and adults) are highly recommended based on the comparative analysis comprising five independent studies.