著者

Fumiaki MIZOBE Yuji TAKAHASHI 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.31, no.4, pp.101-104, 2020 (Released:2020-12-18)

参考文献数

14

被引用文献数

2 3

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Jockey safety is of paramount importance from the standpoint of welfare and public perception. Thus, an understanding of the epidemiology and associated risk factors is necessary to implement measures to reduce the jockey falls (JFs) and jokey injuries (JIs). This descriptive epidemiological study investigated the occurrence of JFs and JIs in 715,210 and 25,183 rides in flat and jump races, respectively, from 2003 to 2017. In flat races, the incidence rates of JFs and JIs were 1.4 and 0.6 per 1,000 rides, respectively. In jump races, they were 44.4 and 18.1 per 1,000 rides, respectively. In flat races, 56.8% of JFs at corners resulted in JIs. In jump races, the major causes of JFs and JIs were lost balance and hampered by a fallen horse at an obstacle. Our findings provide a basis to design a future study analyzing risk factors for JFs.

著者

Teruaki TOZAKI Aoi OHNUMA Mio KIKUCHI Taichiro ISHIGE Hironaga KAKOI Kei-ichi HIROTA Natasha A. HAMILTON Kanichi KUSANO Shun-ichi NAGATA

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.75-83, 2020 (Released:2020-12-18)

参考文献数

24

被引用文献数

6

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Gene doping is prohibited in horseracing and equestrian sports. In previous studies, we developed non-targeted transgene and genome editing detection methods based on whole genome resequencing (WGR) using genomic DNA extracted from whole blood. In this study, we aimed to develop a WGR method using DNA extracts from hair roots. Hair roots are a preferred substrate because their collection is less invasive than blood collection. Hair is also easier to store for long periods of time. Although almost all genomic DNA extracted from hair root samples stored for years at room temperature was degraded, the quality of genomic DNA from samples stored for years at refrigerated temperatures (4–8°C) was maintained. High-molecular-weight genomic DNA was isolated from hair roots using a magnetic silica beads method of extraction, enabling WGR from horsehair root extracts. Nucleotide sequencing results and numbers of single-nucleotide polymorphisms and insertions/deletions concurred with those previously reported for WGR of DNA extracted from whole blood. Therefore, we consider that storing hair samples at refrigerated temperatures prevents degradation of DNA, allowing the detection of gene doping in these samples based on WGR. It is likely this finding will also have a deterrent effect, as it is now possible to test horses with archived samples even if they or their parents are deceased. To our knowledge, this is the first report employing WGR on horsehair roots stored for a long term.

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

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

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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.