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

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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

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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

柴田 眞美

出版者

Japanese Society of Equine Science

雑誌

Japanese Journal of Equine Science (ISSN:09171967)

巻号頁・発行日

vol.4, no.1, pp.45-54, 1993-09-30 (Released:2010-06-28)

参考文献数

12

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本研究では,体表のレリーフ表現について調べた前報に引き続いて,古今東西の造形作例(267作例)に描かれたウマのポーズについて,独自の指標を用いて実際のウマの歩行運動中の位相と比較し,その表現方法の特性について検討した。 分析指標を作成するために,数頭の実馬に各種の歩行運動をさせ,それをVTRカメラで撮影した。その映像からウマの動作を1コマ毎(30Hz)に作図し,こたらの位相を着地肢の組合せによって分類し,作例分析のための指標とした。各作例について,そこに描かれたウマの着地肢の組合せ,四肢の配置パターン,そして全体の姿勢,の3つの視点から分析指標と照合し,描かれた歩法とその四肢の位相を判定した。 その結果,全体の83%にあたる222作例が,分析指標のいずれかの位相に分類する事ができた。また,描写頻度の高さから判断して,造形上で好まれるポーズは,次に示すグループとして捉えることができた;両後肢で立ち上がっているポーズ,対角前後肢が着地している速歩のポーズ,四肢全てが地から離れているリーピングギャロップもしくは同じ位相の飛越のポーズ,1方の前肢と両後肢が着地している常歩のポーズ,両後肢が着地しているリーピングギャロップもしくは同じ位相の飛越のポーズ,の5ポーズ,あるいはこれらに類似したポーズである。一方,造形表現上であまり用いられないポーズは,四肢すべてが着地している駈歩のポーズ,両前肢と一方の後肢が着地している常歩もしくは同じ位相の駈歩のポーズ,対角前後肢が着地している駈歩もしくは同じ位相の襲歩のポーズ,両前肢が着地しているリーピングギャロップもしくは同じ位相の飛越のポーズ,一方の前肢が着地している襲歩,同じ位相のリーピングギャロップ,もしくは同じ位相の飛越のポーズであった。 さらに,時代あるいは地域別にその作例を検討した結果,美術解剖学の分野で「詩的真実」と呼ばれている「造形表現と実体との相違」について考察する際に大変興味ある問題がいくつか提示された。

著者

徳力 幹彦

出版者

Japanese Society of Equine Science

雑誌

Japanese Journal of Equine Science (ISSN:09171967)

巻号頁・発行日

vol.2, pp.1-10, 1992-03-31 (Released:2010-06-28)

参考文献数

84

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

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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

3

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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 22

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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

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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

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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

沖 博憲 深谷 徳善

出版者

Japanese Society of Equine Science

雑誌

日本中央競馬会競走馬総合研究所報告 (ISSN:03864634)

巻号頁・発行日

vol.1983, no.20, pp.11-15, 1983-12-01 (Released:2010-08-10)

参考文献数

3

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It is an important problem to study diurnal changes in measurements of body parts in the Thoroughbred when a large number of horses are measured in the course of a day. In this study, 24 body parts were measured in 43 Thoroughbreds at three different times, the day before training, immediately after training, and after grazing. As a result, there were significant chronological differences in the measurements of few parts by the analysis of variance, but such difference was significant at 5% levels in thickness of the breast. The difference in thickness of the breast, however, was considered to be within the range of measuring error. It seems to be the best way to measure Thoroughbreds at the same time on the same day, but no statistical errors will be produced, if all horses are measured on the same day.

著者

天田 明男 千田 哲生 久保 勝義 大石 幸子 桐生 啓治

出版者

Japanese Society of Equine Science

雑誌

日本中央競馬会競走馬保健研究所報告 (ISSN:03685543)

巻号頁・発行日

vol.1974, no.11, pp.51-69, 1974-12-01 (Released:2011-02-23)

参考文献数

32

---

競走馬2例の心房細動に遭遇したので,臨床生理学的に観察した。各症例別の観察結果はつぎのとおりであった。 症例1:サラブレッド,牡,1962年生。 1965年12月のレースにおいて競走途中で突然にスピードが落ち1着馬から5.6秒遅れて入線した。心電図検査の結果,心房細動と診断された。その後,乗馬に転用されたが,1970年3.月に殺処分するまで心房細動が持続した。その間の観察所見はつぎのとおりであつた。 心電図所見:P波欠如し,f波が連続的に出現しその周波数は分あたり400~500であった。心拍間隔は極度に不整で,0.4~2.1秒の間で変動していた。QRS幅は0.12秒,Q-T間隔は0.40秒で正常範囲であった。運動中においても心拍間隔の不整がみられ,f波は消失しなかった。さらに運動中において異常に心拍数が増加した。心音図所見:各弁開口部において1音の振幅が大きく,かつその大きさは拍動毎に変化した。右心房内圧:37~65mmHgであり,a,z,c,x,v,yの各波は認められなかった。頸動脈頸動脈血圧:心拍間隔の不整に伴って血圧曲線も変動し,縮期圧は171~123(142±11.5)mmHg,弛緩期圧は148~99(121±12.1)mmHg,脈圧は40~9(21±4.6)mmHgであった。 症例2:繋駕速歩馬,牝,1963年生。 1967年9,月,調教中に馬場で転倒した。その後,乗馬に転用されたが心電図検査により心房細動と診断された。 心電図所見:基本的所見は症例1と同様であった。安静時心拍間隔は0.8~3.28秒(1.71±0.85秒)の範囲で変動し,QRS幅は0.09秒,Q-T間隔は0.50秒,f波の周波数は360~480/分であった。運動中の心電図検査においても症例1と同様所見がみられたが,心拍数は最高258/分まで増加し,さらに心室粗動の短かい発作が散発した。心音図所見:症例1と同様の所見であった。 本例は細動除去のためにアドレナリン作動β遮断薬(プロプラノロール)を投与したが不成功に終った。ついで1968年7月に硫酸キニジンを3目間に計55g投与したところ,除細動に成功した。その後,殺処分された1970年2月まで細動の再発はなく,洞調律が持続した。

著者

保地 真一 崔 龍鎬 Joachim W. BRAUN 佐藤 邦忠 小栗 紀彦

出版者

Japanese Society of Equine Science

雑誌

Japanese Journal of Equine Science (ISSN:09171967)

巻号頁・発行日

vol.4, no.2, pp.145-150, 1994-03-31 (Released:2011-11-29)

参考文献数

21

被引用文献数

4 4

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ウマの屠場卵巣からの卵子の採取効率,ならびにそれらの体外培養における第2減数分裂中期への成熟率に影響を及ぼす要因を検討した。卵胞吸引法では1年の試験期間を通して一定の卵子数(卵巣当たり1.3-1.6個)が採取されたが,卵胞吸引に続いて行った卵巣細切法では春季と冬季の卵巣から効率よく卵子が回収された。両法により採取された一卵巣当たり卵子数は,春季(3-5月)で平均5.8個,夏季(6-8月)で3.6個,秋季(9-ll月)で4.0個,冬季(12-2月)で5.1個となった。ウマの品種に関しては軽種馬よりも重種馬の卵巣から多くの卵子が採取された(卵巣一個当たりそれぞれ4.4個,7.6個)。いずれの品種においても屠殺時のウマの年齢は卵子の採取率に影響を及ぼさなかった。春季と冬季の体外成熟率(それぞれ55.5%,58.3%)は夏季や秋季のそれ(それぞれ64.4%,65.7%)とのあいだに有意な差はなかったが,若干低くなる傾向が認められた。軽種馬と重種馬から採取された卵子の体外成熟率には差は認められなかった(それぞれ53.7%,58.7%)。卵巣の保管時間についてはウマの屠殺から卵子採取までの時間が3時間のときの卵子の成熟率は62.3%であったのに対し,6時間で45.0%,9時間で30.4%に低下した。培養小滴当たりの卵子数はそれらの成熟率に影響を及ぼさなかった(卵子数が1-5個のとき55.1%,6-10個のとき56.3%,11-15個のとき50.8%)。ウシ胎子血清の存在下では58.1%の卵子が成熟したが,ウシ血清アルブミンや無血清下でさえそれぞれ62.1%,65.3%の成熟率が得られた。培養気相は成熟率に影響を及ぼさなかった(5%CO295%空気で60.6%に対し,5%CO2 5%02 90%N2 で53.6%)。

著者

上田 八尋 仁木 陽子 吉田 光平 益満 宏行

出版者

Japanese Society of Equine Science

雑誌

日本中央競馬会競走馬総合研究所報告 (ISSN:03864634)

巻号頁・発行日

vol.1981, no.18, pp.28-41, 1981-12-01 (Released:2010-08-10)

参考文献数

10

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馬の跛行診断を客観的に行うために, あるいは運動器疾患の原因を解明するためにフォースプレートを用い, 常歩あるいは速歩時に着地した肢に働く床反力を測定し検討した.フォースプレートはキスラー社製Z4852/C (60×90cm) を用いた. 測定項目は垂直分力 (Fz), 前後分力 (Fy), 左右分力 (Fx) と, さらに演算によって合力 (F), 力の作用点の軌跡 (ax, ay), 力の作用点における垂直軸周りのトルク (M'z) (ねじりの力), それに力線図 (リサージュ波形) が得られ波形として描かれる.常歩において, 垂直分力は前後肢ともに2峰性のパターンが得られた. そのピーク値は前肢において体重比56.2%と68.0%であり, 後肢においては48.6%と42.9%であった. さらに垂直分力波形には2つの小峰が認められた. 1つは最初のピークの前であり, 他の1つは第2のピークの後であった.前後分力は着地後, 前方分力としてピークを形成したあと0にもどり, 次いで後方分力としてのピークを形成した. そして, 前方分力と後方分力はほぼ等しい値であった. また, 前後分力の波形の中にも垂直分力の小峰に対応した小峰が認められた.左右分力は個体によって異ったパターンが見られ, 着地から離地までにいくつかの内外側へのピークを形成していた.速歩になると, 垂直分力は前後肢とも単峰性のパターンに変化し, そのピーク値は前肢において体重比105%, 後肢において92.8%となった. 前後分力は常歩時とほぼ同様のパターンを示したが, 前肢の前方分力と後肢の後方分力が常歩時より増加した. 左右分力は個体間の変動が大きく, 常歩と速歩による変化は見られなかった.力の作用点の軌跡 (ax, ay) は, 前後肢によってそれぞれほぼ一定したパターンを示し, そのパターンは関節の作用, 体重心の位置と関連があるように見られた. また, ねじりの力は個体差及び各個体の各肢ごとに相違があり, 肢勢, 歩様と関連性が強いと推察された. 力線図については, 着地時の衝撃波の影響が強く現われたが, 個々の馬の歩様を反映しているように思われた.測定結果から前肢は支持的な機能を, 後肢は推進力としての機能を持っていることが表わされている. また, 各波形は馬の歩様を忠実に示しており, 跛行診断などへの有用性が示唆された.

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

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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

6

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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

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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

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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

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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

7

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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

中西 信吾

出版者

Japanese Society of Equine Science

雑誌

Japanese Journal of Equine Science (ISSN:09171967)

巻号頁・発行日

vol.1, pp.13-15, 1991-03-31 (Released:2010-06-28)

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馬の受胎率が牛に比べ低いことは,これまでの報告から明らかであるが,その理由は,主として馬の繁殖生理上の特異性にあるものと考えられる。 我国における近年の軽種馬の繁殖に関するデータは,毎年,日本軽種馬協会から刊行される軽種馬生産統計に1年間の交配牝馬頭数と子馬生産頭数が掲載されるに過ぎず,そのほかの詳細なデータは公表されていない。馬の生産率の向上が可能か否かを検討するためには,馬の繁殖の現状を把握することが不可欠である。 今回,軽種馬の近年の繁殖状況を明らかにするために,日本軽種馬協会の内部資料と同協会軽種馬改良情報システムのデータを基に,1984~1988年の軽種馬繁殖成績の分析を試みた。なお,繁殖牝馬の産歴に関しては,日本軽種馬登録協会の血統書を用いて検索した。 調査対象は,日本軽種馬協会所属の種牡馬延べ151頭で交配した延べ4,009頭の繁殖牝馬であった。その内訳は,サラブレッド延べ3,741頭,アングロアラブ延べ246頭,アラブ延べ20頭およびサラブレッド系延べ29頭であった。各牝馬の繁殖成績から,受胎率,生産率,および生産に関する損耗率を算出した。なお,本調査では,分娩後3カ月以上生存した子馬を正常産駒として取り扱った。したがって,正常産駒を分娩した場合を生産とし,妊娠と診断されたが生産しなかった場合(胎子死滅,流産,死産,産後直死など)を損耗とした。 得られた結果の大要は,以下に示すとおりである。