Mane Hair Research Articles

Detection of nonsteroidal and steroidal selective androgen receptor modulators in equine hair after oral administrations.

This paper describes the detections of nonsteroidal and steroidal selective androgen receptor modulators (SARMs), namely, RAD140 and YK-11, in mane hair collected from horses having been orally administered with the respective drugs. SARMs are potent anabolic agents with a high potential of misuse in horseracing and equestrian sports, and the misuses of RAD140 and YK-11 in human sports have been reported. To better control the misuse of RAD140 and YK-11 in horses, two separate oral administration studies of RAD140 (0.3mg/kg daily for 3days) and YK-11 (0.2mg/kg daily for 3days) were previously conducted to investigate their metabolism and to identify target analyte(s) with the longest detection time in urine and plasma for doping control. In this work, segmental analyses of post-administration hair samples have revealed that (i) RAD140 and YK-11 could be detected in horse mane after oral administration and (ii) internal incorporation of RAD140 into hair via bloodstream and external incorporation through sweat or sebum were both observed, whereas YK-11 was primarily incorporated into hair via sweat or sebum.

Detection of methandienone and its metabolites in equine urine, plasma and hair following a multidose oral administration.

Methandienone is an anabolic-androgenic steroid that is prohibited in equine sports due to its potential performance enhancing properties. Metabolism and detection of methandienone in equine urine have been investigated comprehensively in literature; however, there is a limited knowledge about its metabolites in equine plasma and no information about its detection in equine hair. Following a multi-dose oral administration of methandienone to two Thoroughbred horses, 17-epimethandienone, methyltestosterone, two mono-hydroxylated, two di-hydroxylated and three 17α-methylandrostanetriol metabolites were detected in plasma. The majority of these were present as free analytes, whilst the mono-hydroxylated metabolites and one isomer of 17α-methylandrostanetriol were partially conjugated. Estimated peak concentrations of methandienone were 6,000 and 11,100 pg/ml; meanwhile, they were 25.4 and 40.5pg/ml for methyltestosterone. The most abundant analyte in the post-administration plasma samples of both horses was the mono-hydroxylated metabolite; however, the parent compound provided the longest detection (up to 96 h). Screening analysis of hair enabled the detection of methandienone in mane hair samples only, for up to 3months. Its mono- and di-hydroxylated metabolites were detected with greater peak responses for up to 6months post-administration in both mane and tail samples, showing that these metabolites could be better analytical targets for hair analysis when administered orally. A follow-up methodology with an extensive wash procedure confirmed the presence of methandienone and its metabolites in a number of post-administration hair samples. Final wash samples were also analysed to assess the degree of internal incorporation (via bloodstream) against possible external deposition (via sweat/sebum).

Detection of FG-4592 and metabolites in equine plasma, urine and hair following oral administration.

FG-4592 is a hypoxia-inducible factor inhibitor that has been approved for therapeutic use in some countries. This class of compounds can increase the oxygen carrying capacity of the blood and thus have the potential to be used as performance enhancing agents in sports. The purpose of this study was to investigate the detection of FG-4592 and metabolites in equine plasma and mane hair following a multiple dose oral administration to two Thoroughbred racehorses, to identify the best analytical targets for doping control laboratories. Urine samples were also analysed, and the results compared to previously published urine data. Liquid chromatography-high resolution mass spectrometry was used for metabolite identification in urine and plasma. Liquid chromatography-tandem mass spectrometry was used for full sample analysis of urine, plasma and hair samples and generation of urine and plasma profiles. FG-4592 and a mono-hydroxylated metabolite were detected in plasma. FG-4592 was detected with the greatest abundance and gave the longest duration of detection, up to 312 h post-administration, and would be the recommended target in routine doping samples. FG-4592 was detected in all mane hair samples collected post-administration, up to 166 days following the final dose, showing extended detection can be achieved with this matrix. To the best of the authors' knowledge, this is the first report of FG-4592 and metabolites in equine plasma and hair samples. Urine results were consistent with the previously published data, with FG-4592 offering the best target for detection and longest detection periods.

Evaluation of short-term hair follicle storage conditions for maintenance of RNA integrity.

Hair follicles provide an easily accessible tissue for interrogating gene expression for multiple purposes in mammals. RNAlater® is a liquid storage solution that stabilises and preserves cellular RNA, eliminating the need to immediately process or freeze tissue specimens. The manufacturer advises storage of samples at 2-8°C overnight before transfer to -20°C. This study aimed to evaluate RNA integrity in hair follicle samples collected from horses, stabilized in RNAlater®, and stored under three short-term storage conditions. Mane hair samples complete with follicles were collected from four horses at a single time point. Approximately 15 hairs were placed in each of three 2 mL tubes containing 0.75ml RNAlater® solution. Test group A was stored at 4°C for 24-h, then decanted and stored at -20°C. Test groups B and C were stored at 4°C and 19°C (room temperature) respectively for 7 days, then decanted and stored at -20°C. RNA was isolated from all samples and RNA quantity and quality were measured. One-way ANOVA revealed no difference in RNA concentration (A:516 +/-125 ng/ml, B:273+/-93 ng/ml, C:476+/-176 ng/ml;P = 0.2) or quality (A:9.5 +/-0.19, B:9.8+/-0.09, C:9.2+/-0.35 RIN; P = 0.46) between the test groups. There were no group differences in mean Cycle Threshold values from qPCR validation assays confirming high-quality template cDNA. The results suggest that storage of hair follicles for one week in RNAlater® at cool or room temperature conditions will not compromise RNA integrity and will permit extended transport times from remote sampling locations without the need for freezing.

Physical, thermal and mechanical properties of horse tail and mane hairs

Purpose This study aims to comparatively reveal the physical, thermal and mechanical properties of horse tail and mane hairs, which have the potential to be used in many areas. Design/methodology/approach Physical properties of horsehairs such as diameter, density, moisture and water absorption were measured. Fourier transform infrared, field emission scanning electron microscopy and amino acid analyzes were applied to the hairs. Thermal stability of horsehair was investigated by thermogravimetric analysis and differential scanning calorimetry analysis. In addition, breaking strength and elongation values of mane and tail hairs were measured. Findings As a result of morphological analysis of horsehair, it was observed that there are usually gaps in the internal structure of horsehair, but the size and continuity of these gaps vary. It has been determined that there is a significant difference between the tenacity values of tail and mane hairs as well as geometric characteristics. In addition, amino acid analysis has shown that the amino acid contents of horse tail and mane hairs are similar and not much different from sheep’s wool. Originality/value Horsehair has been used for various purposes such as clothing, accessories, brushes, upholstery and reinforcement material. To use horsehair in accordance with its application area and performance characteristics, it is necessary to know its physical, thermal and mechanical properties. It is considerable to reveal the similar and different aspects of tail and mane hairs to determine whether they are alternatives to each other. Therefore, revealing the characteristics of tail and mane hairs comparatively constitutes the originality of this study.

Segmental analysis andlong-term monitoring ofvadadustat inequine hair forthe purpose ofdoping control.

Vadadustat is a newly launched hypoxia-inducible factor stabilizer with anti-anemia and erythropoietic effects; however, its use in horses is expressly forbidden in both racing and equestrian competitions. Following our previous report on the pharmacokinetic study of vadadustat in horse plasma and urine, a long-term longitudinal analysis of vadadustat in horse hair after nasoesophageal administration (3 g/day for 3 days) to three thoroughbred mares is described in this study. Our main objective is to further extend the detection period of vadadustat for the purpose of doping control. Three bunches of mane hair from each horse were collected at 0 (pre), 1, 2, 3 and 6 month(s) post-administration. These hair samples were each cut into 2-cm segments and pulverized after decontamination of hair samples. The analyte in the powdered hair samples was extracted with liquid-liquid extraction followed by further purification by solid-phase extraction with strong anion exchange columns. The amount of vadadustat incorporated into the hair was quantified with a newly developed and validated method using liquid chromatography-high-resolution mass spectrometry. Our results show that vadadustat was confirmed in all post-administration hair samples, but its metabolites were not present. Thus, the detection window for vadadustat could be successfully extended up to 6 months post-administration. Interestingly, the 2-cm segmental analysis revealed that the tip of the drug band in the hair shifted along with the hair shafts in correspondence with the average hair growth rate (∼2.5 cm/month) but gradually diffused more widely from 2 cm at 1 month post-administration to up to 14 cm at 6 months post-administration. However, the loss in the total amount of vadadustat in hair over time was observed to most likely be due to the degradation of vadadustat. These findings will be useful for the control of abuse and/or misuse of vadadustat and the interpretation of positive doping cases.

First evidence of the incorporation of daprodustat and other hypoxia-inducible factor stabilizers into equine hair by passive transfer based on segmental quantitative analysis

Daprodustat is a hypoxia-inducible factor prolyl hydroxylase domain (HIF-PHD) inhibitor and is used as an erythropoiesis stimulant for the treatment of anemia in humans. In general, administering daprodustat to horses will result in a lifetime ban from both equestrian sports and horseracing by the International Federation of Horseracing Authorities and the Fédération Équestre Internationale, respectively. To control the misuse/abuse of daprodustat, we conducted nasoesophageal administration of daprodustat (100 mg/day for 3 days) to three thoroughbred mares and the post-administration hair samples collected from the three horses over 6 months were analyzed to demonstrate the potential longer-term detection of daprodustat and its metabolites in hair compared with the detection times of daprodustat of 1 and 2 weeks in plasma and urine respectively. The results of the quantitative 2-cm segmental analysis showed that daprodustat was primarily localized in the proximal region (0–2 cm) at 0.375–0.463 pg/mg at 1 month post-administration. These drug bands were gradually spread out along the hair shaft at a rate consistent with the reported growth rate of horse mane hair (approximately 2.5 cm/month) over the following 6 months. In addition, to attain deeper insight into the mechanism of drug incorporation into hair, a total of 11 relevant parameters, including the actual PK parameters and simulated physicochemical and biopharmaceutical parameters for three HIF stabilizers (i.e., daprodustat, vadadustat, and IOX4), were investigated after normalization of the z-scores of all these parameters. Multiple regression analysis indicated that the major factors contributing to the incorporation of the three drugs into hair were their maximum plasma concentrations and lipophilicities, strongly suggesting that the three HIF stabilizers permeated from the bloodstream into the hair bulb via passive transfer with concentration gradients. This work is the first reported evidence showing the incorporation of HIF stabilizers into hair via passive transfer. In addition, cross-species comparison of drug incorporations into hair between daprodustat in horse and roxadustat in human was made in order to have a better understanding of the interactive interpretations about the analysis results obtained from different species. The above findings are not only useful and beneficial for the purpose of doping control but also provide a better understanding of the mechanism of drug incorporation into horse hair.

Optimised Stable Lighting Strengthens Circadian Clock Gene Rhythmicity in Equine Hair Follicles.

Hair follicles (HF) represent a useful tissue for monitoring the circadian clock in mammals. Irregular light exposure causes circadian disruption and represents a welfare concern for stabled horses. We aimed to evaluate the impact of two stable lighting regimes on circadian clock gene rhythmicity in HF from racehorses. Two groups of five Thoroughbred racehorses in training at a commercial racehorse yard were exposed to standard incandescent light or a customized LED lighting system. The control group received light from incandescent bulbs used according to standard yard practice. The treatment group received timed, blue-enriched white LED light by day and dim red LED light at night. On weeks 0 and 20, mane hairs were collected at 4 h intervals for 24 h. Samples were stored in RNAlater at -20 °C. RNA was isolated and samples interrogated by quantitative PCR for the core clock genes: ARNTL, CRY1, PER1, PER2, NR1D2, and the clock-controlled gene DBP. Cosinor analyses revealed 24 h rhythmicity for NR1D2 and PER2 and approached significance for CRY1 (p = 0.013, p = 0.013, and p = 0.051, respectively) in week 20 in the treatment group only. No rhythmicity was detected in week 0 or in week 20 in the HF of control horses. Results suggest that lighting practices in racehorse stables may be improved to better stimulate optimum functioning of the circadian system.

Zinc Status of Horses and Ponies: Relevance of Health, Horse Type, Sex, Age, and Test Material

Little is known about the animal- and diet-related factors that could interfere with the plasma zinc (Zn) concentrations of equines. Additionally, the adequacy of plasma to reflect changes in the Zn intake is unclear. In the first part of this study, the plasma Zn concentrations of hospitalized horses and ponies (n = 538) were measured and evaluated for the impact of the age, sex, horse type, and internal diseases of the animals. In the second part, the effects of increasing dietary Zn chloride hydroxide and Zn methionine supplementations were assessed on the plasma and mane hair Zn concentrations of healthy horses (n = 2) and ponies (n = 8). Part 1: The age, sex, and horse type did not influence the plasma Zn concentrations. No effect of internal diseases was observed, with the exception of higher plasma Zn concentrations in animals with metabolic disorders compared to the control group (p < 0.05). Part 2: Both Zn supplements dose-dependently increased the Zn concentrations in the mane hair (p = 0.003), but not in the plasma of the horses and ponies. In conclusion, the plasma Zn concentrations were widely unaffected by nutritional and non-nutritional factors in equines, while mane hair samples better reflected the dietary Zn supply.

The mane factor: Compliance is associated with increased hair cortisol in the horse

Equine personality tests enable the selection of horses for roles based on their habitual behavioural responses to challenges, aiming to maximise performance and safeguard equine welfare. However, existing research has identified that behavioural responses to acute challenges do not correlate well with stress physiology in the horse. The aim of this study was to investigate whether chronic stress physiology is related to habitual compliance in horses. Hair cortisol concentration (HCC), a long-term biomarker of hypothalamic–pituitary–adrenal axis activity and stress, was assayed in mane hair from the withers, midpoint of the neck and poll of 24 riding school horses (66% male, mean age 13 ± 4 years). Three caregivers provided scores for Agreeableness, Neuroticism, Extroversion, Gregariousness Towards People and Gregariousness Towards Horses for all subjects using a validated equine personality questionnaire. A gamma GLMM was used to model HCC as a function of personality scores and potential confounders of HCC (age, sex, hair colour and sampling location). Individual horses were fitted as random intercepts in the model. Manual backward selection was used to identify the best-fitting plausible model. Mean HCC was 3.8 ± 1.2 pg/mg. The final model only retained Agreeableness and sampling location as explanatory variables of HCC. A positive association was found between Agreeableness (reflecting habitual compliance) and hair cortisol concentration (t = 2.7, p = 0.01). Basal cortisol levels are known to drive sensitivity to punishment in humans. Therefore, horses with higher basal cortisol may be more sensitive to the aversive cues associated with negative reinforcement and consequently be more compliant. However, it is also possible that habitually compliant behaviour leads to higher chronic stress levels through increased exposure to stressors, as more subtle expressions of discomfort are not recognised by handlers. This result has important implications for welfare in the context of horse-human interaction and warrants further investigation to clarify whether a causal link exists between habitual compliance and higher levels of chronic stress. There was also a weaker but significant impact of sampling location (t = 2.1, p = 0.03; higher HCC at the poll), highlighting the importance of carefully standardizing sampling location for HCC analysis.

Impact of Variability Factors on Hair Cortisol, Blood Count and Milk Production of Donkeys.

The increased interest in donkeys because of their milk has led to changes in their farm management. Little is known about the effect of the farming systems on donkey health and welfare. Measuring hair cortisol concentrations is an emerging method to assess stress in animals. To the best of our knowledge, no cortisol assessment has been done on dairy donkeys; similarly, only a few studies have investigated donkey haematological values. The aim of this study was to evaluate the effects of the lactation phase, parity and season on blood parameters, milk yield and quality and hair cortisol in dairy donkeys. Individual samples of milk, blood and mane hair were taken from twenty jennies at 1, 6 and 10 months after parturition. Higher values of hair cortisol were found in the first sampling, suggesting temporary stress during the peri-parturition. The parity influenced the number of blood cells, which was lower in the pluriparous jennies. The season affected milk quality and mean corpuscular haemoglobin and mean corpuscular haemoglobin concentration. The latters might represent the adaptation to the environmental conditions. This study contributes to a better understanding of the biochemical processes occurring in lactating jennies, and to their physiological and wellbeing status.

Commercial Hair Analysis in Horses: A Tool to Assess Mineral Intake?

The use of hair samples to assess the mineral intake of horses under practical conditions has recently been attracting increased interest. The aims of this study were to compare mineral analysis results in equine mane hair between three commercial laboratories and to determine the relationship between the mineral intake and mineral content in mane hair. Four warmblood horses (14 ± 3 years) were included in the study. Horses were fed hay ad libitum and a commercial mineral supplement to meet nutrient requirements under maintenance conditions. Mane hair from the hairline was collected with a sample length of 2 to 3 cm according to the respective laboratory guidelines to monitor the feeding period of the last 1 to 2 months. Minerals in mane hair were analyzed by three commercial laboratories using inductively coupled plasma mass spectrometry (ICP–MS) or inductively coupled plasma optical emission spectroscopy and in feedstuffs using ICP–MS to calculate mineral intake. Hair mineral analysis showed that the results and their corresponding reference ranges widely varied among the three laboratories. The mean coefficient of variance ranged from a minimum of 10% for selenium (Se) to a maximum of 58% for iron (Fe). For example, Se supply (requirement, 1.17–1.28 mg/d; intake, 1.83 mg/d) was considered insufficient in all horses by two laboratories, whereas it was considered adequate by one laboratory. Intervariation of the same sample, as well as differences in reference ranges, was considerably high among the three laboratories. These results indicate that hair mineral analysis is not reliable for assessing mineral intake in horses.

Evaluation of hair analysis for determination of trace mineral status and exposure to toxic heavy metals in horses in the Netherlands.

Analysis of hair to gain insight into the trace mineral status and exposure to toxic heavy metals of horses is attractive because hair is an easily accessible sample material. To investigate the potential value of hair analysis in horses for determination of trace mineral and heavy metal concentrations, we analyzed mane hair and liver samples from 62 horses presented for slaughter at a facility in the Netherlands that receives horses from all regions of the country. Hair samples were cleaned in warm water. After acid digestion of hair and liver specimens, we quantified, with inductively coupled plasma-mass spectrometry, arsenic, cadmium, chromium, cobalt, copper, iron, lead, manganese, molybdenum, nickel, selenium, vanadium, and zinc in the digests. Based on Pearson product moment correlations, we found no statistically significant correlations between concentrations of trace minerals in liver and hair, with the exception of a slight correlation for copper that was too weak to be of clinical relevance. Our results do not support the use of hair to determine trace mineral status and exposure to toxic heavy metals in the horse under field conditions.

Regular positive reinforcement training increases contact-seeking behaviour in horses

Horses are commonly trained using negative reinforcement. However, a growing body of scientific evidence supports positive reinforcement as an efficient training method for horses. In this study we investigated the effects of adding a small but regular amount of positive reinforcement training to horses trained with negative reinforcement. A total of 36 privately owned horses not previously trained with positive reinforcement were divided into a training (N = 17) and a control (N = 19) group. The owners in the training group were asked to follow a training plan based on positive reinforcement for eight to nine weeks, in addition to their normal negative reinforcement training. The control horses continued with their usual negative reinforcement training. All horses were subjected to behavioural tests before and after the training period: a motionless human test to assess contact-seeking behaviour and a cognitive bias test to assess emotional state. Mane hair samples were obtained from all horses at the start and at the end of the training period to analyse hair cortisol concentrations as an expression of long-term stress. In addition, all owners filled out a questionnaire about their perceived relationship with their horses before and after the training period. We found that horses in the training group engaged in more physical contact (P = 0.050) with an unfamiliar person after the training period compared to before. The training group also tended to improve their owner-assessed relationship score (P = 0.072). They did not, however, show changes in their emotional state as assessed by the cognitive bias test (P > 0.1). Furthermore, we found no difference between the training and control groups in terms of hair cortisol concentrations. We conclude that a small but regular addition of positive reinforcement training can increase horses’ contact-seeking behaviour towards humans but is not enough to improve their emotional state or long-term stress levels.

Long-term monitoring of IOX4 in horse hair and its longitudinal distribution with segmental analysis using liquid chromatography/electrospray ionization Q Exactive high-resolution mass spectrometry for the purpose of doping control.

IOX4, a hypoxia-inducible factor stabilizer, is classified as a banned substance for horses in both horse racing and equestrian sports. We recently reported the pharmacokinetic profiles of IOX4 in horse plasma and urine and also identified potential monitoring targets for the doping control purpose. In this study, a long-term longitudinal analysis of IOX4 in horse hair after a nasoesophageal administration of IOX4 (500 mg/day for 3 days) to three thoroughbred mares is presented for the first time for controlling the abuse/misuse of IOX4. Six bunches of mane hair were collected at 0 (pre), 1, 2, 3, and 6 month(s) postadministration. Our results showed that the presence of IOX4 was identified in all postadministration horse hair samples, but no metabolite could be detected. The detection window for IOX4 could achieve up to 6-month postadministration (last sampling point) by monitoring IOX4 in hair. In order to evaluate the longitudinal distribution of IOX4 over 6 months, a validated quantification method of IOX4 in hair was developed for the analysis of the postadministration samples. Segmental analysis of 2-cm cut hair across the entire length of postadministration hair showed that IOX4 could be quantified up to the level of 1.84 pg/mg. In addition, it was found that the movement of the incorporated IOX4 band in the hair shaft over 6 months varied among the three horses due to individual variation and a significant diffusion of IOX4 band up to 10 cm width was also observed in the 6-month postadministration hair samples.

PSXV-19 Informative value of study of mineral composition of the mane hair to assess quality of stallions’ sperm

Abstract The research aim was to study the effect of the elemental status of stallions detected by concentration of chemical elements in the mane hair on the quality indicators of sperm. The research was done on stallions of Arabian breed (n = 54) aged from 5 to 15 years. Hair samples were taken from plot of the mane in the area of projection of the first cervical vertebra (not less 0.24g). The elemental composition of biosubstrates was explored for 5 toxic elements (Al, Cd, Pb, Sn, Sr) by atomic emission and mass spectrometry (AES-ICP and MS-ICP). Spearman rank correlation was calculated at the first stage of the experiment that demonstrated negative correlation of Sr in the hair with volume of ejaculate (r=-0.55; P &amp;lt; 0.05) and total number of progressive motile spermatozoa (r=-0.31; P &amp;lt; 0.05). The entire research sample was divided into three groups: I - concentration of Sr in the hair below 1.88 mcg/g; II – within 1.89 – 3.89 mcg/g; III – above 3.9 mcg/g. Comparative analysis showed that stallions with Sr levels below 1.88 mcg/g (group I) exceed stallions from group II by ejaculate volume by 18.2%; sperm survival in hypothermic sperm preservation after cryopreservation by 24.1% (P &amp;lt; 0.05); total spermatozoa number by 14.6% (P &amp;lt; 0.05); total number of progressive motile spermatozoa by 15.0% (P &amp;lt; 0.05). Difference in the value of the studied parameters between the animals of groups I and III was even more pronounced and was at the level of 38.2% (P &amp;lt; 0.01); 34.7 (P &amp;lt; 0.05); 23.7 (P &amp;lt; 0.05); 26.7% (P &amp;lt; 0.05), respectively. The research was carried out with the support of Russian Science Foundation (project №. 17-16-01109 P).

77 Trace elements in whole blood and mane hair of horses fed varying sources and levels of trace elements

There has been interest in using hair as a marker for mineral status in horses, but there is a lack of quality research to develop a method to do so. The objectives of this study were to determine if dietary supply of minerals would affect blood and mane hair element concentrations and if there would be a relationship between blood and mane hair element concentrations. Nine mature geldings were used in a replicated 3 × 3 Latin square design. All horses had ad libitum access to forage and 3 dietary treatments were provided by a soybean meal pellet: organic trace minerals (ORG), inorganic trace minerals (ING), and no added trace minerals (CON). The ING and ORG pellet provided the same amount of Co, Cu, Mn, Se, and Zn (between 100 and 380% of NRC requirements), but varied in source and CON provided levels of minerals between 15 and 170% of NRC requirements depending on the mineral. There were 3 21-d treatment periods, including a 5-d washout, so each horse received each treatment. Before the first period, a 3 to 4 cm section of mane hair at the poll was clipped close to the skin. On the last day of each treatment period, blood and mane hair were collected. Mane hair was clipped from the same poll area so only new hair growth was collected. Hair and blood were analyzed for Co, Cr, Cu, Mn, Se, Pb, and Zn using ICP-MS. Data were analyzed using ANOVA with treatment, period, and square replicate as effects. The effect of mane hair color on mineral concentration was evaluated using an ANOVA with hair color as the main effect (black, n = 5; chestnut, n = 3; 1 gray, not included). Means were separated using LSD test. Correlations between hair and blood elements were made using Pearson correlation coefficients. Blood Co tended to be lowest in CON compared with other treatments (P = 0.071). Blood Cr tended to be greatest (P = 0.107) and blood Se was greatest (P < 0.05) in ORG compared with CON, with ING not different from either group. Hair Co was greatest in ORG compared with ING, but CON was not different from either (P < 0.05). Hair Cr tended to be greatest in CON compared with ING, with ORG not different from either (P = 0.102). Hair Pb was greatest in CON compared with the other treatments (P < 0.05). The only correlation between blood and hair was a weak trend for blood Co to be correlated with hair Co (r = 0.347; P = 0.076). Across all treatments, black hair had greater concentrations of Se and lower concentrations of Zn than chestnut hair (P < 0.05). While this study did not find correlations between hair and blood, mineral level and source did alter blood and hair concentrations of certain elements independently, and hair color influences mineral deposition.

Reference intervals of essential and toxic elements concentrations in mane hair and blood serum of Arabian purebred horses

The article presents the results of studies on the establishment of reference intervals of concentrations of the main essential and toxic elements in mane hair and blood serum of Arabian purebred horse stallions, calculated by Atomic emission spectroscopy (AES) and Inductively coupled plasma mass spectrometry (ICP-MS) methods. For mane hair, these values are Ca 81,28-1875; K 57,2-2134; Mg 93,92-1154; Na 16,76-542; P 47,1-827,3; Co 0,008-0,201; Cr 0,022-1,35; Cu 0,936-9,73; Fe 18,55-363; I 0,006-0,367; Mn 0,407-8,34; Se 0,039-0,625; Zn 14,49-201; B 0,311-25,66; Li 0,027-0,82; Ni 0,05-0,712; Si 0,809-34; V 0,018-0,594; Al 5,98-208; As 0,009-0,116; Cd 0,001-0,021; Hg 0,002-0,008; Pb 0,02-0,571; Sn 0,001-0,097; Sr 0,311-5,94. For blood serum, these values are Ca 106,2-161,3; K 89,19-187,1; Mg 18,16-27,05; P 78,32-153,1; Co 0,0003-0,0015; Cr 0,0003-0,0101; Cu 0,7-1,46; Fe 1,35-3,51; Mn 0,0005-0,0043; I 0,007-0,019; Se 0,118-0,208; Zn 0,502-0,952; Al 0,01-0,028; As 0,001-0,004; Cd 0-0,0001; Hg 0,0002-0,0009; Pb 0,0001-0,0026; Sn 0-0,0001; Sr 0,14-0,367. It was found that the chemical elements concentration in hair is significantly higher (1.4-2707 times) compared to blood serum; it makes this biosubstrate more informative for the elemental status evaluation. The results of the correlation analysis indicate the absence of a reliable correlation between the content of the studied elements in hair and blood serum.

Dependence of speed qualities and elemental status on the mercury level in the mane hair of purebred riding horses

To assess the influence of the level of mercury in the hair from the mane on athletic performance and elemental status of horses, a study was carried out on purebred horse breed stallions. Age at the time of sampling of hair 5-7 years. The elemental composition of biosubstrates was determined by 25 indicators, by atomic emission and mass spectrometry (AES-ICP and MS-ICP). The assessment of the speed qualities of stallions was carried out in sports competitions according to the time of passing a distance of 2400 meters. It was found that the effect of the level of mercury in the hair from the mane on the speed qualities of stallions (r = −0.57). Moreover, if stallions with a mercury concentration of less than 0.0018 mg/kg spent 158.6 ± 3.5 seconds to overcome the distance, then at a level of 0.0767-0.304 mg/kg, on average 15 seconds longer. Comparison of the groups with the boundaries of the reference intervals of the concentrations of chemical elements in the mane showed that the high agility of the horses was associated with a relatively smaller number of elements exceeding the boundaries of the intervals, so if there were four of them in group I: K, Na, I, Sn, then in II and III groups of them were eight Ca, K, Na, I, Zn, Pb, Sn, Hg and Ca, Cu, Zn, B, Si, Li, Sn, Hg, respectively. It was revealed that the elemental composition of the hair of the mane is closely related to the sports results of thoroughbred riding horses, and for some of them the changes exceeded 250% (Si). It was concluded that it is necessary to study the concentrations of Hg and Si in the hair from the main during preparation for the competition, for their further correction.

Detection and longitudinal distribution of GW1516 and its metabolites in equine hair for doping control using liquid chromatography/high-resolution mass spectrometry.

GW1516 is a peroxisome proliferator-activated receptor-δ (PPAR-δ) agonist that is banned in horseracing and equestrian sports. Long-term detection and longitudinal distribution of GW1516 in the mane of a horse are reported for the first time and this hair analysis could prolong the detection window of GW1516 for doping control. Mane hairs were divided into three segments (0-7, 7-15, and >15 cm from the cut end) and completely pulverized and homogenized for analysis. The pulverized hair samples were extracted with methanol followed by further purification and the extracts were analyzed by liquid chromatography/electrospray ionization high-resolution mass spectrometry (LC/ESI-HRMS) using a Q-Exactive instrument. This method was successfully validated and applied to post-administration samples to confirm the presence of GW1516 and its metabolites and estimate the uptake amounts of GW1516. After administration of 150 mg of GW1516 to a thoroughbred mare, GW1516 was detected in one of two segments of all mane hairs, and four metabolites, namely GW1516 sulfoxide, GW1516 sulfone, 5-(hydroxymethyl)-4-methyl-2-(4-trifluoromethylphenyl)thiazole (HMTT), and 4-methyl-2-[4-(trifluoromethyl)phenyl]-1,3-thiazole-5-carboxylic acid (MTTC), were also identified. The longitudinal distribution analysis results showed that the maximum uptake of GW1516 into hair (approximately 0.05 pg/mg) was observed at around 13 weeks post-administration and GW1516 could be detected and confirmed up to 6 months post-administration. The parent drug GW1516 was identified as the most appropriate monitoring target in equine hair for controlling its misuse in horses. The use of hair analysis could extend the detection time of GW1516 to at least 6 months after the administration of 150 mg of GW1516 to a thoroughbred mare.