著者
Koji HARADA Saori KANEMITSU Kohei AKIOKA Kazunari FUJITA Yasunobu NISHI Yasuho TAURA Naoki SASAKI
出版者
Japanese Society of Equine Science
雑誌
Journal of Equine Science (ISSN:13403516)
巻号頁・発行日
vol.33, no.1, pp.7-12, 2022 (Released:2022-04-19)
参考文献数
15
被引用文献数
1

Fifty-four slaughtered horses were classified into groups having adipose tissue in the crest of the neck with or without hemorrhage (AH and NH groups, respectively). Blood biochemical tests (Alb, TP, T-bil, GOT, GPT, LDH, T-cho, and BUN) and an epidemiological survey (age, gender, weight, origin, breed, BCS, CNS, and hoof disease) were performed. T-bil tended to be high, while the other parameters were normal. Weight, BCS, and CNS were higher in the AH group (P<0.05). GOT was lower in the AH group (P<0.05). It was suspected that the horses in the AH group had lipomatosis. It was assumed that the adipose tissue of the horses in the AH group contained damaged capillaries, and inflammation was confirmed based on evidence of macrophages and lymphocytes.
著者
Hajime OHMURA Atsushi HIRAGA
出版者
Japanese Society of Equine Science
雑誌
Journal of Equine Science (ISSN:13403516)
巻号頁・発行日
vol.33, no.1, pp.13-17, 2022 (Released:2022-04-19)
参考文献数
26
被引用文献数
2

This study aimed to investigate the effect of transportation and restraint in a van on heart rate (HR) and HR variability in Thoroughbreds. Eight healthy Thoroughbreds were exposed to four conditions, each for a duration of 30 min: stall rest (REST), restraint inside a van (VAN), restraint inside a van with the engine running (V + E), and road transportation (TRANS). Electrocardiograms were recorded to determine HR, low-frequency (LF) power, high-frequency (HF) power, and LF/HF ratio. During TRANS, HR was significantly greater than during REST and V + E. There was a significant increase during VAN compared with REST. These results demonstrated that restraint inside the transport vehicle was one of the major stressors that may cause physiological changes during transportation.
著者
Naoki SASAKI Yasunobu NISHI Yumi FUJIWARA Tetsuya TAKEYAMA Hayata KUMAGAI Samantha SENARATHNA Shigeto USHIYA Takashi TOKUYAMA Takahito TOKUYAMA Takaaki TOKUYAMA Tomohiro MII Satomi AYAKI Kosuke MATSUNO Yuki NAKAGAWA Yoshitaka NISHIHARA Yasuho TAURA
出版者
Japanese Society of Equine Science
雑誌
Journal of Equine Science (ISSN:13403516)
巻号頁・発行日
vol.32, no.2, pp.27-30, 2021 (Released:2021-06-18)
参考文献数
15
被引用文献数
1

Gastric ulcers cause appetite loss, poor body condition, and colic in horses. This study investigated the protective effect of a rice fermented extract on the gastric mucosa in 17 healthy Thoroughbreds. For one month, horses in the rice fermented extract (nine horses) and control (eight horses) groups were orally administered a rice fermented extract (100%; 0.2 ml/kg, SID) and tap water (0.2 ml/kg), respectively. Gastric endoscopic images were obtained before and one month after rice fermented extract administration. The gastric ulcer score was lower after administration (median, 1; maximum, 2; minimum, 1) than before administration (median, 4; maximum, 4; minimum, 3) in the rice fermented extract group (P<0.05). In conclusion, the administration of a rice fermented extract for one month improves gastric mucosal lesions in Thoroughbreds with gastric ulcers.
著者
Akihiro MATSUURA Maiko DAN Aiko HIRANO Yoshio KIKU Suzuka TORII Shigeru MORITA
出版者
Japanese Society of Equine Science
雑誌
Journal of Equine Science (ISSN:13403516)
巻号頁・発行日
vol.32, no.3, pp.73-80, 2021 (Released:2021-09-09)
参考文献数
21
被引用文献数
2

The measurement of various body dimensions of horses plays a significant role in quality improvement, genetic breeding, health, and soundness. There has been significant advancement in the technology for acquiring stereoscopic images with a three-dimensional (3D) scanner. This study aimed to validate the accuracy of body measurements obtained from stereoscopic images taken with a 3D scanner. We manually took the following body measurements for 8 riding horses: height at the withers, height at the back, height at the croup, chest depth, width of the chest, width of the croup, width of the waist, girth circumference, cannon circumference, and body length. Using a versatile tablet-type 3D scanning device, we captured a 3D image of each horse. Relative errors varied from −1.37% to 6.25%. The correlation coefficient between manual and 3D measurements was significant for all body measurements (P<0.01) except for width of the waist and cannon circumference. The low accuracy of cannon circumference (r=0.248) was due to effect of hair. A simple regression analysis of all body measurements revealed a strong correlation (P<0.001, R2=0.9994, root-mean-square error [RMSE]=1.522). Notable advantages of this methodology include high accuracy, good operability, non-contact, high versatility, and low cost. Further studies are required for the establishment of an accurate measurement methodology that can scan the whole body in a shorter time.
著者
Marshall GRAMM Ryne MARKSTEINER
出版者
Japanese Society of Equine Science
雑誌
Journal of Equine Science (ISSN:13403516)
巻号頁・発行日
vol.21, no.4, pp.73-78, 2010 (Released:2011-01-29)
参考文献数
15
被引用文献数
14 21

Using a dataset of 274 male Thoroughbred racehorses in the United States, we study the effect of age on racing performance. Beyer speed figures, which are uniform measures of racing performance across distance and racing surface, are utilized in this study. A system of equations is estimated to determine quadratic improvement and decline in racing performance. We find that a typical horse's peak racing age is 4.45 years. The rate of improvement from age 2 to 4 1/2 is greater than the rate of decline after age 4 1/2. A typical horse will improve by 10 (horse) lengths in sprints (less than 1 mile) and 15 lengths in routes (one mile or greater) from age 2 to 4 1/2. Over the next five years the typical decline is 6 lengths for sprints and 9 1/2 lengths for routes.
著者
Fumiaki MIZOBE Ai WAKUNO Jun OKADA Tasuku OTSUKA Yuhiro ISHIKAWA Shinjiro KURIMOTO
出版者
Japanese Society of Equine Science
雑誌
Journal of Equine Science (ISSN:13403516)
巻号頁・発行日
vol.28, no.4, pp.143-147, 2017 (Released:2017-12-12)
参考文献数
20
被引用文献数
1 2

A total of 20 racehorses with longitudinal fractures underwent internal fixation surgery under sevoflurane anesthesia combined with infusion of medetomidine (3 µg/kg/hr) alone (10 horses, group M) or medetomidine and fentanyl (7 µg/kg/hr) (10 horses, group FM). In group FM, the end-tidal sevoflurane concentration during surgery was maintained significantly lower than in group M (2.8–2.9% for group M vs. 2.2–2.6% for group FM, P<0.01). The mean arterial blood pressure was maintained over 70 mmHg using dobutamine infusion (group M, 0.36–0.54 µg/kg/min; group FM, 0.27–0.65 µg/kg/min), and the recovery qualities were clinically acceptable in both groups. In conclusion, co-administration of fentanyl and medetomidine by constant rate infusion may be a clinically useful intraoperative anesthetic adjunct for horses to reduce the requirement of sevoflurane when they undergo orthopedic surgery.
著者
Fumiaki MIZOBE Motoi NOMURA Tomohiro KATO Yasuo NAMBO Kazutaka YAMADA
出版者
Japanese Society of Equine Science
雑誌
Journal of Equine Science (ISSN:13403516)
巻号頁・発行日
vol.28, no.3, pp.87-97, 2017 (Released:2017-09-20)
参考文献数
26
被引用文献数
3 4

Problems associated with the proximal metacarpal region, such as an osseous injury associated with tearing of Sharpey’s fibers or an avulsion fracture of the origin of the suspensory ligament (OISL), are important causes of lameness in racehorses. In the present study, four Thoroughbred racehorses (age range, 2–4 years) were diagnosed as having forelimb OISL and assessed over time by using standing magnetic resonance imaging (sMRI). At the first sMRI examination, all horses had 3 characteristic findings, including low signal intensity within the trabecular bone of the third metacarpus on T1-weighted images, intermediate-to-high signal intensity surrounded by a hypointense rim on T2*-weighted images, and high signal intensity on fat-suppressed images. Following the sMRI examination, all horses received 50 mg of tiludronic acid by intravenous regional limb perfusion once weekly for 3 weeks. Attenuation of the high signal intensity on T2*-weighted and fat-suppressed images was observed on follow-up sMRI in 3 horses. Following rest and rehabilitation, these 3 horses successfully returned to racing. In contrast, the other horse that did not show attenuation of the high signal intensity failed to return to racing. To our knowledge, this is the first report of OISL in Thoroughbred racehorses assessed over time by sMRI under tiludronic acid treatment. Our findings support the use of sMRI for examining lameness originating from the proximal metacarpal region to refine the timing of returning to exercise based on follow-up examinations during the recuperation period.
著者
Hajime OHMURA Kazutaka MUKAI Akira MATSUI Toshiyuki TAKAHASHI James H. JONES
出版者
Japanese Society of Equine Science
雑誌
Journal of Equine Science (ISSN:13403516)
巻号頁・発行日
vol.31, no.4, pp.67-73, 2020 (Released:2020-12-18)
参考文献数
23
被引用文献数
4

Supramaximal exercise while inspiring different O2 gases may induce different responses in cardiopulmonary function at the same relative and/or absolute exercise intensity. The purpose of this study was to compare the effects of supramaximal exercise in hypoxia, normoxia and hyperoxia on cardiopulmonary function in Thoroughbred horses. Using a crossover design, five well-trained horses were made to run up a 6% grade on a treadmill at supramaximal speeds sustainable for approximately 110 sec (approximately 115% VO2max) while breathing normoxic gas (NO, 21% O2) or hypoxic gas (LO, 15.3% O2) in random order. Horses also ran at the same speed, incline and run time as in NO while breathing hyperoxic gas (HONO, 28.8% O2) and as in LO while breathing normoxic gas (NOLO). Runs were on different days, and cardiopulmonary variables were analyzed with repeated-measures ANOVA and the Holm-Šidák method for pairwise comparisons. Supramaximal speeds differed significantly between NO and LO (14.0 ± 0.5 [SD] m/sec vs. 12.6 ± 0.5 m/sec), but run times to exhaustion did not (112 ± 17 sec vs. 103 ± 14 sec). The VO2max in NO was higher than that in LO (165 ± 11 vs. 120 ± 15 ml (min× kg)), as was the arterial oxygen tension (66 ± 5 vs. 45 ± 2 Torr). Oxygen consumption was increased in HONO and NOLO compared with the values in NO and LO, respectively. Supramaximal exercise in hypoxia induces more severe hypoxemia and decreases VO2max compared with normoxia at the same relative intensity. Conversely, supramaximal exercise in hyperoxia alleviates hypoxemia and increases VO2 compared with normoxia at the same absolute intensity.
著者
Mohamed B. MOSTAFA Yahya M. ELEMMAWY
出版者
Japanese Society of Equine Science
雑誌
Journal of Equine Science (ISSN:13403516)
巻号頁・発行日
vol.31, no.2, pp.23-27, 2020 (Released:2020-06-24)
参考文献数
28
被引用文献数
5

There is limited knowledge about causes of musculoskeletal injury in jumping Thoroughbred horses. The objective of this study was to describe the relationships between musculoskeletal disorders and linear and angular limb measurements acquired from photographs of horses with markers at specific reference points. The diagnosed musculoskeletal disorders in either fore or hind limbs were flexor tendonitis, suspensory ligaments desmitis, and osteoarthritis of the distal intertarsal and tarso-metatarsal and carpometacarpal joints. Lengths and angles in 17 clinically normal jumping Thoroughbred horses and 34 horses with musculoskeletal problems were measured. Horses with musculoskeletal disorders had significantly shorter neck, shoulder, and pelvis lengths (P<0.05), significantly longer arm and forearm front lengths (P<0.05), and significantly lower front shoulder, elbow, and hind fetlock joint angles (P<0.05). In conclusion, this study describes significant relationships between linear and angular morphometric measurements and musculoskeletal disorders in jumping Thoroughbred horses. These data could possibly provide indicators for better selection of jumpers with less risk of developing orthopedic disorders.
著者
Eric K. BIRKS Hajime OHMURA James H. JONES
出版者
Japanese Society of Equine Science
雑誌
Journal of Equine Science (ISSN:13403516)
巻号頁・発行日
vol.30, no.4, pp.87-92, 2019 (Released:2019-12-18)
参考文献数
26
被引用文献数
2

Measurements of gas exchange while breathing gases of different O2 concentrations are useful in respiratory and exercise physiology. High bias flows required in flow-through indirect calorimetry systems for large animals like exercising horses necessitate the use of inconveniently large reservoirs of mixed gases for making such measurements and can limit the amount of equilibration time that is adequate for steady-state measurements. We obviated the need to use a pre-mixed reservoir of gas in a semi-open flow-through indirect calorimeter by dynamically mixing gases and verified the theoretical accuracy and utility of making such measurements using the mass-balance N2-dilution method. We evaluated the accuracy of the technique at different inspired oxygen fractions by measuring exercising oxygen consumption (VO2) at two fully aerobic submaximal exercise intensities in Thoroughbred horses. Horses exercised at 24% and 50% maximum oxygen consumption (VO2 max) of each horse while breathing different O2 concentrations (19.5%, 21% and 25% O2). The N2-dilution technique was used to calculate VO2. Repeated-measures ANOVA was used to tested for differences in VO2 between different inspired O2 concentrations. The specific VO2 of the horses trotting at 24%VO2max and cantering at 50%VO2max were not significantly different among the three different inspired oxygen fractions. These findings demonstrate that reliable measurements of VO2 can be obtained at various inspired oxygen fractions using dynamic gas mixing and the N2-dilution technique to calibrate semi-open-circuit gas flow systems.
著者
Motoi NOMURA Tomoki SHIOSE Yuhiro ISHIKAWA Fumiaki MIZOBE Satoshi SAKAI Kanichi KUSANO
出版者
Japanese Society of Equine Science
雑誌
Journal of Equine Science (ISSN:13403516)
巻号頁・発行日
vol.30, no.2, pp.17-23, 2019 (Released:2019-07-03)
参考文献数
19
被引用文献数
12

Despite growing recognition of post-race exertional heat illness (EHI) in the horse racing industry, reports on its prevalence are limited. The purpose of this study was to investigate the prevalence of post-race EHI and climate conditions at racecourses in Japan. The overall prevalence of EHI from 1999 to 2018 was 0.04% (387 cases for 975,247 starters) in races operated by the Japan Racing Association (JRA). The yearly prevalence has been increasing, exceeding 0.07% in the last four years of the studied period. The overall prevalence in summer (May–September) was 0.086% (352 cases for 409,908 starters). The monthly prevalence varied among the 10 JRA racecourses, which are distributed from latitude 34 to 43°N, ranging from no cases to 0.459%. During summer, prevalence of post-race EHI was high when the mean monthly ambient temperature was high at a racecourse. To evaluate climate conditions, we investigated the wet-bulb globe temperature (WBGT, °C) from 9 AM to 5 PM on sunny race days in July and August of 2017 and 2018 at three racecourses with a high prevalence of EHI among the 10 racecourses. The durations of time during which WBGT was between 28 and 33°C at these three courses were 95, 94, and 65% of the minutes measured, respectively. This result indicated that most races on the sunny summer days were held when WBGT was between 28 and 33°C at the three racecourses. These findings could be useful in developing the appropriate countermeasures to be taken during hot weather at each of the studied racecourses.
著者
Mioko MASUDA Junko TSUNODA Hiroko NOMURA Nami KIMURA Gombojav ALTANGEREL Bandi NAMKHAI Usukhjargal DOLJ Michinari YOKOHAMA
出版者
Japanese Society of Equine Science
雑誌
Journal of Equine Science (ISSN:13403516)
巻号頁・発行日
vol.18, no.4, pp.145-151, 2007 (Released:2008-01-09)
参考文献数
16
被引用文献数
2

The incidence of Bider (Bi marking) in Mongolian native horses was 0.010, and that according to districts was the highest (0.032) in Tov Aimag. Bi marking was frequently observed in bay (0.482) and chestnut horses (0.351), and was also observed in gray and roan horses. The incidence of Bi marking was high (0.842) in horses with a dorsal strip (DS) as a primitive marking. In 164 Equus przewalskii, the incidence of Bi marking was 0.396, which was about 40 times the incidence in Mongolian native horses. Bi marking was observed in both males and females in the two species, showing autosomal inheritance. Analysis of the mode of inheritance based on the incidence of Bi marking in foals according to various crossing combinations showed the complete dominance of Bi marking in both species. Thus, it was concluded that Bi marking occurs in Bi/Bi and Bi/- genotypes. This Bi marking differs from DS, leg stripes (LS) and shoulder stripes (SS), and is considered to be a type of primitive marking peculiarly occurring in Mongolian native horse and Equus przewalskii. The high incidence of Bi marking in Equus przewalskii (0.396), and the results of crossing between Mongolian native horses and Equus przewalskii performed in Mongolia, suggest introgression of the Bi marking gene from Equus przewalskii to Mongolian native horses.
著者
Toshiki UEDA Teruaki TOZAKI Satoshi NOZAWA Kenji KINOSHITA Hitoshi GAWAHARA
出版者
Japanese Society of Equine Science
雑誌
Journal of Equine Science (ISSN:13403516)
巻号頁・発行日
vol.30, no.3, pp.55-61, 2019 (Released:2019-10-02)
参考文献数
23
被引用文献数
6

Recently, the illegal use of novel technologies, such as gene and cell therapies, has become a great concern for the horseracing industry. As a potential way to control this, metabolomics approaches that comprehensively analyze metabolites in biological samples have been gaining attention. However, it may be difficult to identify metabolic biomarkers for doping because physiological conditions generally differ between resting and exercise states in horses. To understand the metabolic differences in horse plasma between the resting state at training centres and the sample collection stage after racing for doping test (SAD), we took plasma samples from these two stages (n=30 for each stage) and compared the metabolites present in these samples by liquid chromatography-high resolution mass spectrometry. This analysis identified 5,010 peaks, of which 1,256 peaks (approximately 25%) were annotated using KEGG analysis. Principal component analysis showed that the resting state and SAD groups had entirely different metabolite compositions. In particular, the levels of inosine, xanthosine, uric acid, and allantoin, which are induced by extensive exercise, were significantly increased in the SAD group. In addition, many metabolites not affected by extensive exercise were also identified. These results will contribute to the discovery of biomarkers for detecting doping substances that cannot be detected by conventional methods.
著者
Susan ALEXANDER C.H.G. IRVINE
出版者
Japanese Society of Equine Science
雑誌
Journal of Equine Science (ISSN:13403516)
巻号頁・発行日
vol.9, no.3, pp.77-81, 1998 (Released:2001-09-28)
参考文献数
24
被引用文献数
11 14

The hormones of the adrenal axis help athletes adapt to the stress of training and racing. When performance is poor, dysfunction of this axis is often suspected, but confirming this has been difficult. We have found three hallmarks of chronic stress in horses that are easily monitored: 1) loss of the circadian cortisol rhythm, 2) decrease in corticosteroid-binding globulin and an increase in free cortisol, and 3) reduced ACTH (& hence cortisol) response to a small dose (2 μg) of equine/human corticotropin-releasing hormone (CRH). The presence of some or all of these abnormalities is a good indication that the horse is not coping with the stresses imposed upon him.
著者
Jun YAMASHITA Hironori OKI Telhisa HASEGAWA Takeshi HONDA Tetsuro NOMURA
出版者
Japanese Society of Equine Science
雑誌
Journal of Equine Science (ISSN:13403516)
巻号頁・発行日
vol.21, no.2, pp.11-16, 2010 (Released:2010-07-16)
参考文献数
12
被引用文献数
3 4

To investigate the breeding structure in the Japanese Thoroughbred population, we applied a demographic analysis to the populations of foals produced from 1978 to 2005. The migration rate estimated from the proportion of foals produced by imported breeding horses was around 40% over the investigated period. After early 1990s, the migration rate through stallions imported from USA sharply increased. The average generation interval was within range of 10.5-11.5 years. The longer generation interval of Thoroughbred was considered to be a reflection of the fact that Thoroughbred horses begin breeding only after completing their performance in races. After the peak of 729 in 1993, the number of sires of foals progressively declined to 358 in 2005. Although the coefficient of variation of the progeny number of sires was within range of 1.0-1.2 until early 1990s, it gradually increased and reached the value of 1.6-1.7 in recent years. The effective number of sires consistently decreased after the peak of 302.6 in 1992, and reached 120-130 in recent years, which is 25-30% of the actual number of sires. In parallel, the demographic estimate of the effective population size declined after early 1990s. The main cause of the observed change in the breeding structure was inferred to be the intensive use of a limited number of stallions for breeding.
著者
Akira MATSUI Tomoko OSAWA Hirofumi FUJIKAWA Yo ASAI Tohru MATSUI Hideo YANO
出版者
Japanese Society of Equine Science
雑誌
Journal of Equine Science (ISSN:13403516)
巻号頁・発行日
vol.13, no.4, pp.109-112, 2002 (Released:2003-04-10)
参考文献数
13

We examined total sweating rate (SR) and the amount of mineral (Na, K, Ca, Mg, Fe, P, Zn and Cu) loss through sweat in 2-year-old horses during exercise for approximately 2,000 m at a speed of 700 m/min, at cool ambient temperature. The total SR was estimated by the unit area SR on the neck by filter paper within a capsule. Mean total SR was 1.55 ± 0.47 (SD) kg. The ratio of sodium loss to the requirements reported by National Research Council reached 23% and that of potassium was 7%. The ratio of other mineral losses to the requirements reported by National Research Council was 2% or less. These results suggested that sodium had to be supplemented to the horse, but there was no need to add extra minerals to the diet to compensate for mineral losses of calcium, magnesium, iron, phosphorus, zinc and copper through sweat during exercise with light intensity and at a cool ambient temperature.
著者
Hironaga KAKOI Mio KIKUCHI Teruaki TOZAKI Kei-ichi HIROTA Shun-ichi NAGATA Seiji HOBO Masaki TAKASU
出版者
Japanese Society of Equine Science
雑誌
Journal of Equine Science (ISSN:13403516)
巻号頁・発行日
vol.29, no.2, pp.39-42, 2018 (Released:2018-07-06)
参考文献数
23
被引用文献数
10

The distribution of Y chromosomal haplotypes in Japanese native horse populations was investigated to obtain genetic information on these populations. Here, 159 male/gelded horses from eight local populations were investigated, and three Y haplotypes (JHT-1, JHT-2, and JHT-3) were identified by analyzing five Y-linked loci. Five populations had only JHT-1, whereas two populations had only JHT-2. One population had JHT-1 and JHT-3. Based on the geographical distribution of these haplotypes and previously reported haplotypes for other Asian horses, JHT-1 is considered to be a major haplotype in ancestral native horses. The fixation of each haplotype suggests the influence of independent breeding and genetic drift in each population. These findings complement the results from previous genetic studies of Japanese native horses.
著者
Laura CROTCH-HARVEY Leigh-Anne THOMAS Hilary J. WORGAN Jamie-Leigh DOUGLAS Diane E. GILBY Neil R. MCEWAN
出版者
Japanese Society of Equine Science
雑誌
Journal of Equine Science (ISSN:13403516)
巻号頁・発行日
vol.29, no.2, pp.47-51, 2018 (Released:2018-07-06)
参考文献数
13
被引用文献数
7

Anthelmintics are used as anti-worming agents. Although known to affect their target organisms, nothing has been published regarding their effect on other digestive tract organisms or on metabolites produced by them. The current work investigated effects of fenbendazole, a benzimidazole anthelmintic, on bacteria and ciliates in the equine digestive tract and on and their major metabolites. Animals receiving anthelmintic treatment had high faecal egg counts relative to controls. Analysis was performed over two weeks, with temporal differences detected in bacterial populations but with no other significant differences detected. This suggests fenbendazole has no detectable effect on organisms other than its targets. Moreover it does not appear to make a contribution to changing the resulting metabolome.