Hair dehydroepiandrosterone sulfate as biomarker of employees' well-being? A longitudinal investigation of support, resilience, and work engagement during COVID-19 pandemic.

Introduction: Building on the motivational process of the job demands-resources (JD-R) theory, in the current research we investigated the longitudinal association between supervisor support/resilience as job/personal resources, work engagement (WE) and hair dehydroepiandrosterone sulfate, or DHEA(S), as a possible biomarker of employees' well-being. Methods: In the context of the COVID-19 pandemic, 122 workers completed two self-report questionnaires (i.e., psychological data): the former at Time 1 (T1) and the latter three months afterwards, at Time 2 (T2). Participants also collected a strand of hair (i.e., biological data) at T2. Results: Results from path analysis showed that both SS and resilience at T1 were positively related to WE at T2, which, in its turn, was positively related to hair DHEA(S) at T2. Both SS and resilience at T1 had a positive indirect effect on hair DHEA(S) at T2 through WE at T2, which fully mediated the association between job/personal resources and hair DHEA(S). Discussion: Overall, results are consistent with the motivational process of the JD-R. Furthermore, this study provides preliminary evidence for the role of hair DHEA(S) as a biomarker of WE, a type of work-related subjective well-being that plays a central role in the motivational process of the JD-R, leading to favorable personal and organizational outcomes. Finally, the article outlines practical implications for organizations and professionals to foster WE within the workplace.

Validation of a commercial ELISA kit to measure 11-oxoetiocholanolone in equine and bovine feces.

Feces are a noninvasive and easily collectible matrix that may help determine cumulative hormone metabolite concentrations over medium-to-long times. To date, 11-oxoetiocholanolone, an important metabolite of cortisol, has been measured in equine and bovine feces solely by an in-house enzyme immunoassay (EIA). Therefore, we validated the use of a commercial ELISA kit (11-oxoetiocholanolone ELISA kit; Cayman Chemical), which had been validated on sheep feces and human urine, to measure 11-oxoetiocholanolone in feces from 42 horses and 32 bulls. The ELISA kit had good precision (intra- and inter-assay CVs: 5.8% and 11.2% for equine feces; 9.9% and 11.2% for bovine feces, respectively), analytical sensitivity (0.186 ng/mL for both equine and bovine feces), and accuracy (parallelism and recovery tests) in determining 11-oxoetiocholanolone concentrations in feces from both species. We found ranges of 11-oxoetiocholanolone concentrations of 1-109 ng/g in equine feces and 40-302 ng/g in feces of bulls. The Cayman Chemical ELISA kit offers a simple and accessible means of analysis of 11-oxoetiocholanolone in equine and bovine fecal samples.

Peripubertal Testosterone, 17ß-Estradiol and Progesterone Concentrations in Hair and Nails in Dobermann Dogs.

Studies about puberty in dogs are few, probably because many factors are involved in the delicate process of puberty onset, leading to difficulties in the proper enrollment of subjects. Moreover, the use of blood for monitoring hormonal changes can be problematic, and not feasible for long-term studies. Hair and nails proved to be suitable matrices for the retrospective evaluation of hormones' long-term accumulation. This study was performed using hair and nails for the evaluation of testosterone (T), 17ß-estradiol (E2) and progesterone (P4) concentrations to assess possible sexual steroid changes during the peripubertal period in dogs. The results, obtained on five males and five females, showed a significant increase in T in hair and nails of males immediately before puberty. In females, a significant increase in E2 at puberty and a marked increase in P4 after puberty was found in both biological specimens. Sex-related differences were detected only for T hair concentrations, but when the sex and sampling time were considered together, hair and nails T and nails P4 concentrations allowed us to discern between male and female dogs at specific sampling times. The results from this study showed that hair and nails are useful biological specimens for the retrospective evaluation of changes in T, E2 and P4 concentrations in peripubertal dogs.

Incorporation of Testicular Ultrasonography and Hair Steroid Concentrations in Bull Breeding Soundness Evaluation.

Testicular ultrasonography and steroid concentrations (cortisol, dehydroepiandrosterone sulfate (DHEA-S), cortisol/DHEA-S ratio, testosterone) in hair were examined for their utility in the bull breeding soundness evaluation (BBSE). Beef and dairy bulls (n = 16; 2.7 ± 0.4 years old; body condition score 3.2 ± 0.1) of five breeds were maintained under the same conditions at an accredited semen collection center. Bulls underwent routine semen collection twice weekly for 12 weeks and semen was processed and cryopreserved. Ultrasonography and hair sampling were undertaken at the last semen collection. Bulls with homogeneous testicular parenchyma (n = 8) had a higher (p < 0.05) percentage of motile sperm post-thawing compared with bulls with heterogeneous parenchyma (n = 8). There were no differences (p > 0.05) in the hair concentrations of cortisol, DHEA-S, and testosterone between bulls with homogeneous and heterogeneous parenchyma. In bulls with homogeneous parenchyma, hair DHEA-S concentration was positively correlated with percentage motile sperm (R2 = 0.76), progressively motile sperm (R2 = 0.70), and motility yield (R2 = 0.71). The findings indicate that the integration of testicular ultrasonography and hair DHEA-S status in the BBSE could provide a more comprehensive assessment of indicative fertility in bulls. Additionally, ultrasonography can be used in the BBSE when the evaluation of semen parameters is not available.

Validation of an ELISA kit to measure allopregnanolone in human and equine hair.

In humans, allopregnanolone plays important roles in a number of different neurodegenerative disorders, and it has been proposed for use in some therapies. Horses are commonly used as animal models for human neurodegenerative diseases, mental and behavioral disorders, and neuropsychiatric disorders, and there is interest in using hair as a biological sample to study hormones in these conditions. We validated the use of a commercial ELISA kit (DetectX allopregnanolone kit; Arbor Assays), which was designed for serum, plasma, feces, urine, and tissue samples, to assess allopregnanolone in hair samples from 30 humans and 63 horses. The ELISA kit had good precision (intra- and inter-assay CVs: 6.4% and 11.0% for equine hair; 7.3% and 11.0% for human hair, respectively), sensitivity (50.4 pg/mL for both equine and human hair), and accuracy (parallelism and recovery tests) in determining allopregnanolone concentrations in hair from both species. The allopregnanolone concentrations in human hair were 7.3-79.1 pg/mg; the concentrations were 286 ± 141 pg/mg (x̄ ± SD) in mares on the day of parturition and 16.9 ± 5.5 pg/mg in nonpregnant mares. The DetectX ELISA kit offered a simple and accessible analysis of allopregnanolone in human and equine hair samples.

Hair and Claw Dehydroepiandrosterone Concentrations in Newborn Puppies Spontaneously Dead within 30 Days of Age.

The latest intrauterine fetal developmental stage and the neonatal period represent the most challenging phases for mammalian offspring. Toward the term of pregnancy, during parturition, and after birth, the hypothalamic−pituitary−adrenal axis (HPA) is a key system regulating several physiologic processes, through the production of cortisol and dehydroepiandrosterone (DHEA). This study was aimed to assess DHEA concentrations in hair and claws of 126 spontaneously dead newborn puppies, classified as premature puppies (PRE-P), stillborn puppies (STILL-P) and puppies that died from the 1st to the 30th day of life (NEON-P). The possible influence of newborn sex, breed body size, and timing of death on DHEA concentrations in both matrices was evaluated. Claw DHEA concentrations were higher in the PRE-P group when compared to STILL-P and NEON-P puppies (p < 0.05), whilst no significant differences were found in hair for all the studied factors. The results confirm the hypothesis that higher amounts of DHEA are produced during the intrauterine life in dogs, also in puppies that will die soon after birth.

Hair Cortisol and DHEA-S in Foals and Mares as a Retrospective Picture of Feto-Maternal Relationship under Physiological and Pathological Conditions.

Equine fetal hair starts to grow at around 270 days of pregnancy, and hair collected at birth reflects hormones of the last third of pregnancy. The study aimed to evaluate cortisol (CORT) and dehydroepiandrosterone-sulfate (DHEA-S) concentrations and their ratio in the trichological matrix of foals and mares in relation to their clinical parameters; the clinical condition of the neonate (study 1); the housing place at parturition (study 2). In study 1, 107 mare-foal pairs were divided into healthy (group H; n = 56) and sick (group S; n = 51) foals, whereas in study 2, group H was divided into hospital (n = 30) and breeding farm (n = 26) parturition. Steroids from hair were measured using a solid-phase microtiter radioimmunoassay. In study 1, hair CORT concentrations measured in foals did not differ between groups and did not appear to be influenced by clinical parameters. A correlation between foal and mare hair CORT concentrations (p = 0.019; r = 0.312, group H; p = 0.006; r = 0.349, group S) and between CORT and DHEA-S concentrations in foals (p = 0.018; r = 0.282, group H; p < 0.001; r = 0.44, group S) and mares (p = 0.006; r = 0.361, group H; p = 0.027; r = 0.271, group S) exists in both groups. Increased hair DHEA-S concentrations (p = 0.033) and decreased CORT/DHEA-S ratio (p < 0.001) appear to be potential biomarkers of chronic stress in the final third of pregnancy, as well as a potential sign of resilience and allostatic load in sick foals, and deserve further attention in the evaluation of prenatal hypothalamus-pituitary-adrenal (HPA) axis activity in the equine species. In study 2, hormone concentrations in the hair of mares hospitalized for attended parturition did not differ from those that were foaled at the breeding farm. This result could be related to a too brief period of hospitalization to cause significant changes in steroid deposition in the mare's hair.

Metabolic and production parameters of dairy cows with different dry period lengths and parities.

To assess the effects of dry period (DP) length on metabolic, reproductive, and productive parameters, second- (SP) and third- (TP) parity cows were assigned to a traditional (9 weeks, T) or short (5 weeks, S) DP, obtaining four subgroups: second-parity cows with traditional (SPT = 8) and short (SPS = 8) DP, third-parity cows with traditional (TPT = 8) and short (TPS = 10) DP. Plasma insulin-like growth factor-I (IGF-I) and non-esterified fatty acid (NEFA) levels were assessed from 5 weeks before to 14 weeks after parturition. IGF-I concentrations were affected by parity (P < 0.05) and by the interaction of time and DP length (P < 0.01). NEFA levels were affected only by time (P < 0.01). S DP cows showed a shorter interval between calving and ovarian cyclicity resumption (P < 0.01) and a higher milk yield (P < 0.01) and fat and protein corrected milk (P < 0.01) compared with T DP cows. Decreased milk protein content was found in the SPS group compared to the SPT (P < 0.05) and the TPS (P < 0.05) group. In conclusion, a short DP length does not affect reproductive performances, except for hastening the resumption of ovarian cyclicity. A short DP appears to increase milk production and is associated with higher IGF-I levels both in the prepartum and the postpartum period.

Effect of Delivery by Emergency or Elective Cesarean Section on Nitric Oxide Metabolites and Cortisol Amniotic Concentrations in at Term Normal Newborn Dogs: Preliminary Results.

The neonatal response to stress was reported to be related to the type of delivery, that is elective or emergency cesarean sections (ELCS and EMCS, respectively). Nitric oxide (NO) is also reported to be related to uterine inertia, and high levels of NO metabolites (NOs) are associated with physical and emotional stress. The study aimed to assess the concentrations of cortisol (C) and NOs in the amniotic fluid of puppies delivered by ELCS or EMCS. In total, 32 puppies were delivered by ELCS and 22 by EMCS. ANCOVA showed an effect of the ELCS vs. EMCS on both amniotic NOs (p < 0.001) and C (p < 0.001) concentrations. Lower amniotic C concentrations were found at increasing Apgar score (p < 0.001). Higher amniotic NOs concentrations were associated to increasing mother's parity (p < 0.001), puppies' birthweight (p < 0.001), and time of labor within the EMCS group (p < 0.05). A positive correlation between birthweight and amniotic NOs concentrations was also found (p < 0.05) in the EMCS group. Due to the possible concurrence of several compartments (maternal, maybe placental, and fetal) to the final amniotic fluid composition, the definition of the role played by the three compartments in the higher C and NOs concentrations found in amniotic fluids collected from puppies delivered by EMCS than ELCS needs further clarification.

Corpus Luteum Color Doppler Ultrasound and Pregnancy Outcome in Buffalo during the Transitional Period.

This study evaluated corpus luteum (CL) development in buffaloes out of breeding season and assessed an early pregnancy diagnosis. Mediterranean buffaloes (n = 29) were synchronized and artificially inseminated. CL B-mode/color Doppler ultrasonography examinations were performed daily from Days 5 to 10 post-synchronization, recording CL dimensions and blood flow parameters. Blood samples were collected on the same days for the progesterone (P4) assay. Data were grouped into pregnant or nonpregnant and retrospectively analyzed. The total pregnancy rate was 50.0% (13/26) on Day 45. A significant difference between CL average area in pregnant and nonpregnant buffaloes was recorded only on Day 10. Pregnant buffaloes showed a significantly higher mean P4 concentration and higher mean time average medium velocity (TAMV) values from Day 5 to Day 10 compared to nonpregnant buffaloes. Linear regression analysis showed a significant relationship between P4 levels and TAMV. Multiple logistic regression highlighted a significant influence of TAMV on pregnancy outcome, particularly on Day 8. This is probably due to the strong relationship between TAMV and P4 production. Both TAMV and P4 could be used to predict pregnancy starting on Day 6, although a more reliable result was obtained at Day 10. Thus, the period between Days 5 and 10 is critical for CL development during the transitional period in buffalo.

Steroids in pig hair and welfare evaluation systems: combined approaches to improve management in pig breeding?

The aim of the present pilot study was to determine the allostatic load by analysing the hair cortisol and dehydroepiandrosterone­sulphate (DHEA­S) of commercial pigs belonging to different farms having good overall animal welfare according to the CREnBA (Centro di Referenza Nazionale per il Benessere Animale - Brescia, Italy) assessment protocol. The study was conducted on 86 pigs belonging to three farms with a grade higher than 8 on the CReNBA welfare evaluation system. Hair samples were taken by shaving on sows 1­10 days after weaning (Farms 1 and 2) and at the age of 8­10 months (Farm 3). The hormone concentrations were measured by radioimmunoassay. From the box plots, it is evident that the hair cortisol concentrations of animals were different between farms. Conversely, the variability of the hair DHEA­S concentration was similar between the F1 and F2 farms but much lower at F3. For all the variables considered (cortisol, DHEA­S and cortisol/DHEA­S ratio), F2 showed a higher hair concentration level than F1 (P < 0.05). The study's results indicate that the measurement of cortisol and DHEA­S in pig hair shows a different allostatic load between them, although the official welfare evaluation method assessed the farms as having good overall animal welfare.

Analysis of 19 Minerals and Cortisol in Red Deer Hair in Two Different Areas of the Stelvio National Park: A Preliminary Study.

The aim of the study was to perform an investigation on the concentration of 19 minerals and cortisol in red deer (Cervus elaphus) hair, a matrix that is easy to collect with non-invasive and painless sampling, able to represent an integrative values of long-term substance concentrations, and able to give useful information, also when performed on dead animals, given its extreme stability over time. In the study thirty-five animals were included, coming from two different sides of a valley in the Stelvio National Park, where official water analysis had pointed out elevated concentrations of As in one of the two orographic sides. Hair cortisol concentrations were measured using a RIA(Radio Immuno Assay), while minerals were detected using ICP-MS (Inductively Coupled Plasma- Mass Spectrometry). Results showed a negative relationship between cortisol and some mineral concentrations (Li, Co, As, Cd, Cr and Tl) and significant differences in some mineral concentrations between park areas (Al, Co, Cu, Cd and Ni). As, Cr and cortisol differences approached statistical significance. This preliminary study represents a step forward in the study of wildlife allostatic load and a valid method for applications in wildlife management programs, in environmental studies and in public health programs.

Cortisol, DHEA, and Sexual Steroid Concentrations in Fattening Pigs' Hair.

The aim of this study was to analyze the feasibility and reliability of using hair as a matrix to determine the dehydroepiandrosterone (DHEA) and sexual steroid concentrations and the cortisol/DHEA ratio in fattening pigs. The results could be also used to plan future research to identify threshold values in order to set up strategies to control the allostatic load and increase the resilience of fattening pigs before slaughter. The study was conducted on 107 commercial crossbred rearing pigs. The hair samples were taken by shaving at the age of 36 weeks, and concentrations of the hormones were measured using a solid-phase microtiter radioimmunoassay. Females had significantly higher cortisol levels (p < 0.01), significantly lower DHEA concentrations (p < 0.05) and significantly higher cortisol/DHEA ratios (p < 0.01) than barrows. Progesterone was significantly higher in gilts than in barrows (p < 0.01). Testosterone and 17ß-estradiol were significantly higher in barrows than in gilts (p < 0.05). If future research can produce threshold values for the different markers examined, the evaluation of animals under subclinical stress conditions will be possible.

Evaluation of factors involved in the failure of ovum capture in superovulated buffaloes.

The aim of this work was to evaluate factors affecting ovum capture in superovulated buffaloes, by comparing the morphological features of pre-ovulatory follicles and oocytes, the intrafollicular and plasmatic steroid profile, as well as the expression of genes involved in cumulus expansion and steroid cascade in granulosa cells (GCs) and that of genes involved in contraction-relaxation of the oviduct between superovulated and synchronized buffaloes. Italian Mediterranean Buffalo cows were either synchronized by Ovsynch (n = 25) and superovulated (n = 10) with conventional FSH protocol and sacrificed 18 h after last GnRH. Antral follicular count, recovery rate and oocyte quality were recorded, and plasma and follicular fluid were collected for steroid profile determination. In addition, in 10 animals (5/group), GCs were collected to analyse the mRNA expression of gonadotropin receptors (LHR and FSHR) and genes involved in steroid synthesis, as the cytochrome P450 family 19 (CYP19A1) and the steroidogenic acute regulatory protein (STAR). Moreover, oviducts were collected to evaluate the mRNA expression of estrogen receptor 1 (ER1) and the progesterone receptor (PGR), the vascular endothelial growth factor (VEGF) and the VEGF receptors, i.e. the kinase insert domain receptor (FLK1) and the fms related tyrosine kinase 1 (FLT1). No differences were recorded in steroids plasma concentration between synchronized and superovulated animals whereas intrafollicular E2 and P4 concentrations decreased in superovulated group (63.2 ±â€¯10.6 vs 30.3 ±â€¯5.9 ng/mL of E2 and 130.1 ±â€¯19.8 vs 71.6 ±â€¯8.5 ng/mL of P4, respectively in synchronized and superovulated animals; P < 0.05). Interestingly, both the recovery rate (85.7% vs 56.6%, respectively in synchronized and in superovulated animals; P < 0.05) and the percentage of oocytes exhibiting proper cumulus expansion (75% vs 28.1%, respectively in synchronized and in superovulated animals; P < 0.01) decreased in superovulated animals. In addition, the expression of FSHR and CYP19A1 increased while the expression of STAR in GCs decreased (P < 0.05). Finally, in superovulated buffaloes a decreased expression of PGR, ER1, VEGF and its receptor FLK1 in the oviduct was observed. The results suggest that the exogenous FSH treatment impairs steroidogenesis, affecting both the oviduct and the ovarian function, accounting for the failure of ovum capture in superovulated buffaloes.

Hair cortisol and dehydroepiandrosterone concentrations in naturally Taenia solium infected pigs in Tanzania.

The aim of this study was to measure hair cortisol and dehydroepiandrosterone (DHEA) concentrations in naturally Taenia solium infected and non-infected control pigs and assess the effect of an environmental change on the aforementioned parameters. Three hair patches were obtained from 13 T. solium infected and 15 non-infected controls sows, respectively corresponding to 3 time points (prior to, at and approximately two weeks after arrival at the research facility). Cortisol and DHEA were extracted using methanol and analysed by radio immune assay. Mean hair cortisol concentrations were significantly lower (p<0.001) in T. solium infected (4.7±3.0pg/mg) compared to control pigs (9.0±3.7pg/mg) prior to arrival at the research facility, however no significant difference was observed between the two groups at arrival and after approximately two weeks. Similar patterns were also observed for DHEA concentrations (infected pigs 253.9±82.3pg/mg, control pigs 387.7±116.4pg/mg) (p<0.001). Results showed that lean animals had significantly higher cortisol concentrations in both groups, infected and controls pigs, while DHEA was not significantly different between lean and normal animals. Results of this study have shown that an environmental change could have an effect on pigs' hormonal levels suggesting an undergoing adaptation process. After the pigs were kept under the same conditions, fed and watered ad libitum, no significant differences were observed between the groups, but a drop in DHEA concentrations was observed in all the pigs. Weight however had an effect on cortisol levels as lean animals had significantly higher cortisol concentrations in both groups, compared to normal pigs.

Relocation and Hair Cortisol Concentrations in New Zealand White Rabbits.

To investigate how long relocation modified hair cortisol concentrations in New Zealand white rabbits, 19 rabbits were subjected to a change in their breeding facility at the beginning of the trial and then were kept under stable environmental conditions. Hair samples were collected at the time of arrival to the nonhuman animal facility and at 40-day intervals from the same skin area for up to 440 days after the animals' arrival to the facility. A period effect on the hair cortisol concentration was found (p < .01). The transfer of the rabbits to the new facility might have induced an increase in the hypothalamic-pituitary-adrenal axis activity (p < .01). A second increase in hair cortisol concentration (p < .01) occurred at 320 days, after a change of personnel at the facility that occurred at 280 days, which was the only environmental change. The relocation of rabbits to the facility resulted in a stress response leading to elevated cortisol levels. The effect of relocation on mean cortisol concentrations was exhausted within 120 days when all environmental factors were kept stable.

Early development and function of the corpus luteum and relationship to pregnancy in the buffalo.

A detailed study on the structure and function of the CL in the Day-5 to Day-10 window of development, and relationship to the likelihood of pregnancy, was undertaken in Italian Mediterranean buffaloes. In experiment 1, buffaloes underwent synchronization of estrus and fixed-time artificial insemination (n = 23). Features of the CL were measured from Days 5 to 10 after fixed-time artificial insemination, and pregnancy was confirmed on Day 70. Buffaloes that established a pregnancy (n = 14) had a larger CL area (1.31 ± 0.1 vs. 1.09 ± 0.1 cm(2); P < 0.01) and greater progesterone (P4) concentrations (1.90 ± 0.1 vs. 1.48 ± 0.1 ng/mL; P < 0.01) during Days 5 to 10 compared with nonpregnant buffaloes. In the same period, blood flow measured as time average medium velocity tended to be greater (P = 0.059) in buffaloes that were subsequently pregnant versus nonpregnant buffaloes (10.8 ± 0.8 vs. 8.4 ± 0.9). There was a relationship (R(2) = 0.136; P < 0.05) between CL area, P4, and time average medium velocity from Days 5 to 10. Logistic regression analysis showed that P4 concentration on Day 10 had a significant influence on pregnancy (odds ratio, 19.337; P < 0.01). In experiment 2, highly vascularized CLs (HVCLs, n = 3) and lowly vascularized CLs (LVCLs, n = 3) on Day 5 were examined by contrast-enhanced ultrasonography and then subjected to histologic investigation. Blood flow was greater in HVCLs than in LVCLs. Highly vascularized CLs showed intense staining for factor VIII and had many small, irregular-shaped blood vessels, whereas LVCLs had low factor VIII staining and relatively few large, regular-shaped vessels. Luteal cell expression of vascular EGF was greater for HVCLs compared with LVCLs. The study has shown that greater development and function of the CL from as early as Day 5 is related to an increased likelihood of pregnancy in the buffalo. Corpus lutea that show early development at Day 5 have greater expression of vascular EGF and factor VIII, increased vascularization, and higher blood flow.

Effect of season, late embryonic mortality and progesterone production on pregnancy rates in pluriparous buffaloes (Bubalus bubalis) after artificial insemination with sexed semen.

The use of sexed semen technology in buffaloes is nowadays becoming more and more accepted by farmers, to overcome the burden of unwanted male calves with related costs and to more efficiently improve production and genetic gain. The aim of this study was to verify the coupling of some variables on the efficiency of pregnancy outcome after deposition of sexed semen through AI. Pluriparous buffaloes from two different farms (N = 152) were screened, selected, and subjected to Ovsynch protocol for AI using nonsexed and sexed semen from four tested bulls. AI was performed in two distinct periods of the year: September to October and January to February. Neither farms nor bulls had a significant effect on pregnancy rates pooled from the two periods. The process for sexing sperm cells did not affect pregnancy rates at 28 days after AI, for nonsexed and sexed semen, respectively 44/73 (60.2%) and 50/79 (63.2%), P = 0.70, and at 45 days after AI, for nonsexed and sexed semen, respectively 33/73 (45.2%) and 33/79 (49.3%), P = 0.60. Pregnancy rate at 28 days after AI during the transitional period of January to February was higher when compared with September to October, respectively 47/67 (70.1%) versus 47/85 (55.2%), P = 0.06. When the same pregnant animals were checked at Day 45 after AI, the difference disappeared between the two periods, because of a higher embryonic mortality, respectively 32/67 (47.7%) versus 40/85 (47.0%), P = 0.93. Hematic progesterone concentration at Day 10 after AI did not distinguish animals pregnant at Day 28 that would or would not maintain pregnancy until Day 45 (P = 0.21). On the contrary, when blood samples were taken at Day 20 after AI, the difference in progesterone concentration between pregnant animals that would maintain their pregnancy until Day 45 was significant for both pooled (P = 0.00) and nonsexed (P = 0.00) and sexed semen (P = 0.09). A similar trend was reported when blood samples were taken at Day 25, being highly significant for pooled, nonsexed, and sexed semen (P = 0.00). Hematic progesterone concentration between the two periods of the year was highly significant for pregnant animals at 28 days from AI when blood samples were taken at Day 20 after AI for pooled, nonsexed, and sexed semen, respectively P = 0.00, 0.00, and 0.06, and for pregnant animals at Day 45 for pooled, nonsexed, and sexed semen, respectively P = 0.00, 0.00, and 0.01. From these results, it can be stated that hematic progesterone concentration measurement since Day 20 after AI can be predictive of possible pregnancy maintenance until Day 45. Furthermore, the transitional period of January to February, although characterized by a higher pregnancy outcome when compared with September to October, suffers from a higher late embryonic mortality as evidenced by a significant different hematic progesterone concentration between the two periods at Day 20 after AI.

Hair cortisol level as a retrospective marker of hypothalamic-pituitary-adrenal axis activity in horse foals.

Stimulation of the hypothalamic-pituitary-adrenal (HPA) axis and elevated cortisol concentrations in fetal plasma are associated with foal maturity, viability and adaptation to independent life. However, non-invasive measurement of cortisol in hair samples has not yet been validated in horses. The current study developed a radioimmunoassay to analyse cortisol in horse hair and was used to measure cortisol hair concentration at birth and at 30 and 60 days of age as a retrospective study of HPA axis activity. Cortisol was detectable in the hair of foals from birth until 2 months, but decreased with time and varied greatly between individuals. Analysis of hair cortisol could be useful for non-invasive retrospective studies of HPA axis activity in perinatal horse.

Energy balance, leptin, NEFA and IGF-I plasma concentrations and resumption of post partum ovarian activity in Swedish Red and White breed cows.

In the purpose to provide further information in respect of the relationship between metabolism and post partum (PP) ovarian activity resumption in dairy cows, the aim of the present study was to characterize the energy balance (EB) and leptin, NEFA and IGF-I plasma levels in Swedish Red and White (SRW) cows with and without ovarian activity re-initiation within 7 weeks PP. The study was conducted on 12 primiparous SRW cows fed the same diet as total mixed ration for ad libitum intake. The EB was calculated weekly from parturition until seven weeks PP. Blood samples were collected weekly from one week before until 7 weeks after calving for leptin, NEFA and IGF-I analysis. For progesterone (P4) analysis, blood samples were collected two times per week from parturition until the end of the study. P4 profile was used in addition to the clinical examination to detect cows with and without ovarian activity resumption. The clinical and ultrasonographic examination, coupled with P4 profile analysis showed the resumption of ovarian activity within 7 weeks after calving in 8 (group A) and no ovarian resumption in 4 cows (group B). No significant differences were detected in the whole period of observation in the amount of milk production between the two groups, while the mean milk protein content was significantly lower in group B at the third week PP. The calculated EB was negative in both groups in the first three weeks after calving, but more marked in group B. NEFA and Leptin plasma levels did not show significant differences between the two groups. In conclusion, the results of the present study showed that, when low milk producing primiparous cows are concerned, no significant differences in BW loss, milk yield, EB and leptin and NEFA plasma levels between the cows with and without resumption of ovarian activity within 7 weeks post partum were seen. However, significantly higher IGF-I levels in the first two weeks after calving were found in cows with post partum ovarian activity resumption, highlighting the important role of IGF-I as sensitive signal between metabolism and reproduction.