著者

笹谷 遼平 平林 健一 関 正喜

出版者

日本ウマ科学会

雑誌

Hippophile = ヒポファイル (ISSN:18836062)

巻号頁・発行日

no.83, pp.1-11, 2020-12

著者

幾野 博

出版者

日本ウマ科学会

雑誌

Hippophile = ヒポファイル (ISSN:18836062)

巻号頁・発行日

no.80, pp.25-35, 2020-03

著者

吉田 剛 角田 修男 三宅 陽一 シャフィクル ホーク 大澤 健司 長嶺 夏子 谷山 弘行 南保 泰雄 渡辺 元 田谷 一善

出版者

日本ウマ科学会

雑誌

Journal of equine science (ISSN:13403516)

巻号頁・発行日

vol.11, no.2, pp.35-43, 2000-06-01

参考文献数

24

被引用文献数

1

著者

天田 明男 千田 哲生

出版者

日本ウマ科学会

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.1964, no.2, pp.1-8, 1964-03-31 (Released:2011-02-23)

参考文献数

26

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競走馬の不整脈を心電図によって診断する基礎資料を得るため,左側下胸 部(心尖部)と右側肩部からの胸部双極誘導法により,育成馬95頭,競走馬59頭,計154頭の心電図を記録し,次のごとき成績を得た。 (1)P波は殆んどの例で2峰性陽性波が記録された。振幅は,育成馬は平均0・30mV,競走馬でね平均0.34mVであった。持続時間は,育成馬は平均0.13秒,競走馬は平均0.15秒であった。 (2)PQ segmentは,殆んどの例で陰性方向に若干偏位していた。Ta波のためと考える。 (3)QRS群は,rS型またはQS型として出現した。S波の振幅は,育成馬では平均2.40mV.競走馬では平均3.24mVで,競走馬の方が大なる値を示した。持続時間は育成馬では,平均0.11秒,競走馬では平均0.12秒であった。 (4)T波は,育成馬においては-+型2相性波を示したものが多く,競走馬では陽性波を示したものが多かった。 (5)PQ間隔は,育成馬では0.40~0.20秒で平均0.29秒,競走馬では0.50~0.23秒で平均0.32秒であった。 (6)QT間隔は,育成馬では0.54~0.34秒で平均0.45秒,競走馬では0.57~0.34秒で平均0.47秒であった。 (7)PQ間隔とPP間隔との関係式およびPQ間隔の正常範囲は次のようであった:PQ=0.07PP+0.20±0.05 終りに臨み,種々御指導を戴き,かつ本稿の校閲を賜った東大農学部野村晋一助教授に深謝する。また,本実験の実施には宇都宮育成牧場長金子忠三氏ならびに廐舎係員各位,東京競馬場および中山競馬場診療所員各位,馬事公苑教育課員各位の御協力に負う所が多かった。茲にその御厚意に謝意を述べる。

著者

山内 忠平 西中川 駿

出版者

日本ウマ科学会

雑誌

ヒポファイル

巻号頁・発行日

no.1, pp.2-7, 1998-06

著者

柏村 文郎

出版者

日本ウマ科学会

雑誌

Hippophile (ISSN:18836062)

巻号頁・発行日

vol.12, pp.27-38, 2002

著者

柏村 文郎

出版者

日本ウマ科学会

雑誌

Hippophile (ISSN:18836062)

巻号頁・発行日

vol.58, pp.18-25, 2014

著者

桐生 啓治 高宮 勝房 上田 八尋 松永 佳昭 足立 継雄 後藤 芳正

出版者

日本ウマ科学会

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.1965, no.3, pp.71-83, 1965-12-20 (Released:2011-02-23)

参考文献数

10

著者

Amanda YORKE Judith MATUSIEWICZ Barbara PADALINO

出版者

日本ウマ科学会

雑誌

Journal of Equine Science (ISSN:13403516)

巻号頁・発行日

vol.28, no.3, pp.67-75, 2017 (Released:2017-09-20)

参考文献数

73

被引用文献数

22

---

This review aims to provide practical outcomes on how to minimise the incidence of transport-related problem behaviours (TRPBs) in horses. TRPBs are unwanted behaviours occurring during different phases of transport, most commonly, a reluctance to load and scrambling during travelling. TRPBs can result in injuries to horses and horse handlers, horse trailer accidents, disruption of time schedules, inability to attend competitions, and poor performance following travel. Therefore, TRPBs are recognised as both a horse-related risk to humans and a human-related risk to horses. From the literature, it is apparent that TRPBs are common throughout the entire equine industry, and a YouTube keyword search of ‘horse trailer loading’ produced over 67,000 results, demonstrating considerable interest in this topic and the variety of solutions suggested. Drawing upon articles published over the last 35 years, this review summarises current knowledge on TRPBs and provides recommendations on their identification, management, and prevention. It appears that a positive human-horse relationship, in-hand pre-training, systematic training for loading and travelling, appropriate horse handling, and the vehicle driving skills of the transporters are crucial to minimise the incidence of TRPBs. In-hand pre-training based on correct application of the principles of learning for horses and horse handlers, habituation to loading and travelling, and self-loading appear to minimise the risk of TRPBs and are therefore strongly recommended to safeguard horse and horse-handler health and welfare. This review indicates that further research and education with respect to transport management are essential to substantially decrease the incidence of TRPBs in horses.

著者

Siriwan TANGYUENYONG Fumio SATO Yasuo NAMBO Harutaka MURASE Yoshiro ENDO Tomomi TANAKA Kentaro NAGAOKA Gen WATANABE

出版者

日本ウマ科学会

雑誌

Journal of Equine Science (ISSN:13403516)

巻号頁・発行日

vol.28, no.3, pp.77-86, 2017 (Released:2017-09-20)

参考文献数

43

被引用文献数

5

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This study aimed to compare body growth, metabolic, and reproductive hormonal changes in trained Thoroughbred yearling horses under different climate conditions with and without light supplementation (LS). Thoroughbred yearlings raised at research centers of the Japan Racing Association in Hokkaido (north) or Miyazaki (south) were divided into control and LS groups. In the LS groups, 44 colts and 47 fillies from Hokkaido and 11 colts and 11 fillies from Miyazaki were exposed to LS with an extended photoperiod of 14.5 hr of daylight and 9.5 hr of darkness. One week before and once a month after LS, circulating total thyroxine (T4), insulin-like growth factor-I (IGF-1), prolactin (PRL), cortisol, and progesterone (P4) concentrations were measured by radioimmunoassay and fluoroimmunoassay, respectively. Growth parameters, including body weight, height, girth, and cannon bone circumferences, were measured monthly. Hair coat (HC) condition was scored. Under natural conditions, the T4 concentrations of Hokkaido yearlings tended to be higher, whereas the IGF-1 (colt) and PRL levels were significantly lower than those of yearlings in Miyazaki. Growth parameters and HC scores were lower in Hokkaido yearlings. With LS, the PRL and P4 concentrations in Hokkaido and Miyazaki were higher, and the first ovarian activity tended to be earlier than in the controls. Only LS Hokkaido yearlings showed significantly higher HC scores than the controls. Comparing the different climates among the LS yearlings, the levels of PRL and P4 and the HC scores in Hokkaido yearlings increased and reached levels similar to those in Miyazaki yearlings. The body weight and girth increment percentages of Hokkaido yearlings in January dramatically decreased and then eventually increased to levels similar to those of Miyazaki yearlings. This suggested that yearlings in naturally colder Hokkaido exhibit higher basal metabolism to maintain homeostasis. However, providing LS may help to improve growth and early development of reproductive function in Hokkaido yearlings to levels equal to those of Miyazaki horses.

著者

及川 正明 笠嶋 快周

出版者

日本ウマ科学会

雑誌

Journal of equine science (ISSN:13403516)

巻号頁・発行日

vol.13, no.2, pp.41-56, 2002-06-01

参考文献数

55

被引用文献数

1

著者

Teruaki TOZAKI Mio KIKUCHI Hironaga KAKOI Kei-ichi HIROTA Kazutaka MUKAI Hiroko AIDA Seiji NAKAMURA Shun-ichi NAGATA

出版者

日本ウマ科学会

雑誌

Journal of Equine Science (ISSN:13403516)

巻号頁・発行日

vol.27, no.4, pp.157-164, 2016 (Released:2016-12-15)

参考文献数

39

被引用文献数

5

---

Transcriptome analyses based on DNA microarray technology have been used to investigate gene expression profiles in horses. In this study, we aimed to identify exercise-induced changes in the expression profiles of genes in the peripheral blood of Thoroughbred horses using DNA microarray technology (15,429 genes on 43,603 probes). Blood samples from the jugular vein were collected from six horses before and 1 min, 4 hr, and 24 hr after all-out running on a treadmill. After the normalization of microarray data, a total of 26,830 probes were clustered into four groups and 11 subgroups showing similar expression changes based on k-mean clustering. The expression level of inflammation-related genes, including interleukin-1 receptor type II (IL-1R2), matrix metallopeptidase 8 (MMP8), protein S100-A8 (S100-A8), and serum amyloid A (SAA), increased at 4 hr after exercise, whereas that of c-Fos (FOS) increased at 1 min after exercise. These results indicated that the inflammatory response increased in the peripheral blood cells after exercise. Our study also revealed the presence of genes that may not be affected by all-out exercise. In conclusion, transcriptome analysis of peripheral blood cells could be used to monitor physiological changes induced by various external stress factors, including exercise, in Thoroughbred racehorses.

著者

Teruaki TOZAKI Fumio SATO Mutsuki ISHIMARU Mio KIKUCHI Hironaga KAKOI Kei-ichi HIROTA Shun-ichi NAGATA

出版者

日本ウマ科学会

雑誌

Journal of Equine Science (ISSN:13403516)

巻号頁・発行日

vol.27, no.3, pp.107-114, 2016 (Released:2016-09-30)

参考文献数

24

被引用文献数

1 11

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Ligand-dependent nuclear receptor compressor-like (LCORL) encodes a transcription factor, and its polymorphisms are associated with measures of skeletal frame size and adult height in several species. Recently, the single nucleotide polymorphism (SNP) BIEC2-808543 located upstream of LCORL was identified as a genetic diagnostic marker associated with withers height in Thoroughbreds. In this study, 322 Thoroughbreds-in-training were genotyped for BIEC2-808543 to evaluate the association between genotype and body composition traits, including body weight, withers height, the ratio of body weight to withers height, chest circumference, and cannon circumference. Of these, withers height and cannon circumference were significantly associated with LCORL genotypes throughout almost the entire training period in males and females. Animals with a C/T genotype had higher withers height (maximum differences of 1.8 cm and 2.1 cm in males and females, respectively) and cannon circumstance (maximum differences of 0.65 cm and 0.48 cm in males and females, respectively) compared with animals with a T/T genotype. These results suggested that the regulation of LCORL expression influences the skeletal frame size in Thoroughbreds and thus, indirectly affects the body weight. Although LCORL and BIEC2-808543 would be useful for selective breeding in Thoroughbreds, the production of genetically modified animals and gene doping based on genetic information should be prohibited in order to maintain racing integrity.

著者

Yousuke MAEDA Michiko HANADA Masa-aki OIKAWA

出版者

日本ウマ科学会

雑誌

Journal of Equine Science (ISSN:13403516)

巻号頁・発行日

vol.27, no.3, pp.81-97, 2016 (Released:2016-09-30)

参考文献数

141

被引用文献数

21

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This report describes the descriptive epidemiology of racing fractures that occurred from the 1980s to 2000s on racetracks of the Japan Racing Association (JRA). The incidence of racehorse fractures during flat racing was approximately 1–2%. Fractures occurring during a race are more likely to occur in a forelimb. Fractures mostly occur at the third and fourth corners of oval tracks and on the home stretch. They also occur more frequently at the time of changing the leading limb. Comparison of the incidence of racing fracture between before and after reconstruction of the geometrical configuration of a racetrack revealed that there was an outstanding reduction in the number of serious fractures in the year before and after reconstruction. It was postulated that the improvement in racing time, possibly influenced by reconstructing the geometrical configuration of the racetrack, was connected to the reduction in the number of fractures. Of non-biological race- and course-related factors, type of course (dirt or turf), track surface condition, differences between racecourses, and racing distance significantly influence racing time. By using an instrumented shoe, vertical ground reaction forces (VGRFs) on the forelimb during galloping and the relationships between a rough dirt and woodchip track surface and a smooth dirt and woodchip surface were measured. Relating the incidence of racing fractures with track conditions in general showed that track surface has significant effects on the incidence of fracture, with the incidence of fractures increasing as track conditions on dirt worsen and a tendency for the incidence of fractures to decrease as track conditions on turf worsen. It seems probable that track condition in general may affect the incidence of fracture. The incidence of fracture in horses during both racing and training decreased as the years progressed.

著者

Kanichi KUSANO Masahiko YAMAZAKI Masataka KIUCHI Kouki KANEKO Katsuhiro KOYAMA

出版者

日本ウマ科学会

雑誌

Journal of Equine Science (ISSN:13403516)

巻号頁・発行日

vol.27, no.3, pp.125-129, 2016 (Released:2016-09-30)

参考文献数

32

被引用文献数

11

---

The oxidant and antioxidant equilibrium is known to play an important role in equine medicine and equine exercise physiology. There are abundant findings in this field; however, not many studies have been conducted for reference ranges of oxidative stress biomarkers in horses. This study was conducted to determine the reference values of reactive oxygen metabolites (d-ROMs) and biological antioxidant potential (BAP) using blood samples from 372 (191 males, 181 females) Thoroughbred racehorse aged 2 to 5 (3.43 ± 1.10 (mean ± SD)) years old. There were obvious gender differences in oxidative biomarkers, and growth/age-related changes were observed especially in females. Gender and age must be considered when interpreting obtained oxidative stress biomarkers for diagnosis of disease or fitness alterations in Thoroughbred racehorses.

著者

Kazutaka YAMADA Fumio SATO Tohru HIGUCHI Kaori NISHIHARA Mitsunori KAYANO Naoki SASAKI Yasuo NAMBO

出版者

日本ウマ科学会

雑誌

Journal of Equine Science (ISSN:13403516)

巻号頁・発行日

vol.26, no.3, pp.81-87, 2015 (Released:2015-09-30)

参考文献数

24

被引用文献数

1 6

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Bone mineral density (BMD) is one of the indications of the strength and health. BMD measured by quantitative computed tomography (QCT) was compared with that measured by dual energy X-ray absorptiometry (DXA) and radiographic bone aluminum equivalence (RBAE). Limbs were removed from horses that had been euthanized for reasons not associated with this study. Sixteen limbs (left and right metacarpals and metatarsals) from 4 horses were used to compare BMD as measured by QCT with those measured by DXA and RBAE. There was a strong correlation between BMD values measured by QCT and those measured by DXA (R2=0.85); correlation was also observed between values obtained by QCT and those obtained by RBAE (R2=0.61). To investigate changes in BMD with age, 37 right metacarpal bones, including 7 from horses euthanized because of fracture were examined by QCT. The BMD value of samples from horses dramatically increased until 2 years of age and then plateaued, a pattern similar to the growth curve. The BMD values of bone samples from horses euthanized because of fracture were within the population range, and samples of morbid fracture were not included. The relationship between BMD and age provides a reference for further quantitative studies of bone development and remodeling. Quantitative measurement of BMD using QCT may have great potential for the evaluation of bone biology for breeding and rearing management.

著者

Hirotoshi MIZUKAMI Tsuyoshi SUZUKI Yasuo NAMBO Mutsuki ISHIMARU Hiroshi NAITO Kenji KOROSUE Kentaro AKIYAMA Kenji MIYATA Akira YAMANOBE Kentaro NAGAOKA Gen WATANABE Kazuyoshi TAYA

出版者

日本ウマ科学会

雑誌

Journal of Equine Science (ISSN:13403516)

巻号頁・発行日

vol.26, no.2, pp.49-56, 2015 (Released:2015-07-02)

参考文献数

14

被引用文献数

4 11

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Development and endocrine changes in Thoroughbreds colts and fillies were compared between those reared at two facilities of the Japan Racing Association, the Hidaka Training and Research Center (Hidaka) and Miyazaki Yearling Training Farm (Miyazaki). Thoroughbred colts and fillies born in Japan between 2003 and 2010 were used. Each colt group and filly group was divided into 2 groups, respectively, and raised in Hidaka or Miyazaki for 7 months from September at 1 year old to April at 2 years old. For the growth parameters, the body weight, height at withers, and girth and cannon circumferences were measured once a month. For parameters of endocrine function, circulating prolactin, luteinizing hormone (LH), follicle-stimulating hormone (FSH), insulin-like growth factor-1 (IGF-1), testosterone, progesterone, and estradiol-17β levels were measured. Regarding growth, the rate of increase over the 7-month period was significantly higher in both colts and fillies raised in Miyazaki than in Hidaka in all 4 parameters: body weight, height at withers, and girth and cannon circumferences. The endocrine changes of the colts and fillies born in 2007 were as follows. In colts, although circulating prolactin tended to be higher in colts reared in Hidaka from October to April, circulating LH, FSH, testosterone, estradiol-17β and IGF-1 tended to be higher in colts reared in Miyazaki than in Hidaka, suggesting that the gonadotropin-releasing hormone-LH/FSH system and the growth hormone-IGF-1 system were more active in colts reared in Miyazaki as compared with those reared in Hidaka. In fillies, circulating prolactin tended to be higher in fillies reared in Hidaka in February and March, but no significant difference was noted in the serum LH, FSH, IGF-1, or progesterone level between the 2 groups. Circulating estradiol-17β tended to be higher in fillies reared in Miyazaki than in Hidaka in October and November. Regarding ovarian function, the initial ovulation occurred by the end of March in 2 (16.7%) of 12 fillies reared in Hidaka and 7 (38.9%) of 18 fillies reared in Miyazaki, suggesting that the ovarian function was more active in fillies reared in Miyazaki as compared with those reared in Hidaka. Based on these findings, it was clarified that development of the body and gonads was faster in Miyazaki compared with Hidaka in both colts and fillies.

著者

Toshiyuki TAKAHASHI Akira MATSUI Kazutaka MUKAI Hajime OHMURA Atsushi HIRAGA Hiroko AIDA

出版者

日本ウマ科学会

雑誌

Journal of Equine Science (ISSN:13403516)

巻号頁・発行日

vol.25, no.4, pp.73-77, 2014 (Released:2014-12-15)

参考文献数

15

被引用文献数

4

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It is important to know the effects of the inclination of a slope on the activity of each muscle, because training by running on a sloped track is commonly used for Thoroughbred racehorses. The effects of incline (from −6 to +6%) on the forelimbs and hind limbs during walking and trotting on a treadmill were evaluated by an integrated electromyogram (iEMG). The muscle activities in the forelimbs (5 horses) and hind limbs (4 horses) were measured separately. Two stainless steel wires were inserted into each of the brachiocephalicus (Bc), biceps brachii (BB), splenius (Sp), and pectoralis descendens (PD) in the forelimb experiment and into the longissimus dorsi (LD), vastus lateralis (VL), gluteus medius (GM), and biceps femoris (BF) in the hind limb experiment. The EMG recordings were taken at a sampling rate of 1,000 Hz. At a walk, the iEMG values for the forelimb were not significantly different under any of the inclinations. In the hind limb, the iEMG values for the GM and BF significantly decreased as the inclination decreased. At a trot, the iEMG values for the Bc in the forelimb significantly decreased as the inclination of the treadmill decreased. In the hind limb, the iEMG values for the LD, GM, and BF significantly decreased as the inclination decreased. Uphill exercise increased the iEMG values for the Bc, LD, GM, and BF, while downhill exercise resulted in little increase in the iEMG values. It was concluded that the effects of inclination on the muscle activities were larger for the uphill exercises, and for the hind limb muscles compared with the forelimb muscles.

著者

Becu Teotimo 角田 勤 椿 志郎 高井 伸二

出版者

日本ウマ科学会

雑誌

Journal of equine science (ISSN:13403516)

巻号頁・発行日

vol.11, no.2, pp.23-27, 2000-06-01

被引用文献数

3 11 3

著者

Tomoaki ONODA Ryuta YAMAMOTO Kyohei SAWAMURA Harutaka MURASE Yasuo NAMBO Yoshinobu INOUE Akira MATSUI Takeshi MIYAKE Nobuhiro HIRAI

出版者

日本ウマ科学会

雑誌

Journal of Equine Science (ISSN:13403516)

巻号頁・発行日

vol.25, no.2, pp.29-35, 2014 (Released:2014-06-25)

参考文献数

17

被引用文献数

4

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We propose an approach of estimating individual growth curves based on the birthday information of Japanese Thoroughbred horses, with considerations of the seasonal compensatory growth that is a typical characteristic of seasonal breeding animals. The compensatory growth patterns appear during only the winter and spring seasons in the life of growing horses, and the meeting point between winter and spring depends on the birthday of each horse. We previously developed new growth curve equations for Japanese Thoroughbreds adjusting for compensatory growth. Based on the equations, a parameter denoting the birthday information was added for the modeling of the individual growth curves for each horse by shifting the meeting points in the compensatory growth periods. A total of 5,594 and 5,680 body weight and age measurements of Thoroughbred colts and fillies, respectively, and 3,770 withers height and age measurements of both sexes were used in the analyses. The results of predicted error difference and Akaike Information Criterion showed that the individual growth curves using birthday information better fit to the body weight and withers height data than not using them. The individual growth curve for each horse would be a useful tool for the feeding managements of young Japanese Thoroughbreds in compensatory growth periods.