Profile Information
- Affiliation
- Associate Professor, Nippon Veterinary and Life Science University
- Degree
- 獣医学博士(岐阜大学大学院連合獣医学研究科)
- Contact information
- ryotaro.miuranvlu.ac.jp
- J-GLOBAL ID
- 201601007178132049
- researchmap Member ID
- B000254947
Research Areas
1Research History
4-
Apr, 2015 - Mar, 2016
Education
2Papers
46-
Journal of Veterinary Medical Science, 85(7) 715-720, Jul, 2023 Peer-reviewed
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Veterinary Sciences, 10(3) 231-231, Mar 17, 2023 Peer-reviewedLead authorCorresponding authorThe objectives of this study were (1) to investigate the distribution of large (≥10 mm) follicle numbers during the estrous cycle and (2) to compare the timing of the estrus expression period after the ovarian examination between cows with one large follicle (1F) and two or more large follicles (2F) with functional corpus luteum (CL) at the ovarian examination in lactating Holstein dairy cows. In experiment 1, we performed 393 ovarian examinations by ultrasonography, addressed the existence of CL (≥20 mm) and large follicle numbers, and classified cows into 1F (n = 229) and 2F (n = 164) groups. The 1F appearance rates were beyond 75% each day during 3 to 12 d after estrus. However, 2F appearance rates were beyond 75% each day during 15 to 24 d after estrus. In experiment 2, we performed 302 ovarian examinations by ultrasonography and classified cows into the 1F (n = 168) and 2F (n = 134) groups. Estrus detection was performed for 24 d after the ovarian examination in each cow. In the 2F group, 75% of estrus occurred within 9 d of the ovarian examination. However, 75% of estrus occurred 10 d after the ovarian examination in 1F. Days from the ovarian examination to estrus were significantly shorter in the 2F (6.0 d; median, 7.2 ± 4.0 d; mean ± SD) than in the 1F (13 d, 12.4 ± 4.3 d) group. In conclusion, focusing on ≥10 mm follicle numbers with CL could be useful for predicting the estrus expression period.
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Animals : an open access journal from MDPI, 12(23), Dec 2, 2022The objectives of this study were to assess the sequential dynamics of the endometrial polymorphonuclear cells (PMN) after calving by endometrial cytology, and clarify the factors that cause prolonged endometrial inflammation in lactating dairy cows. A total of 33 lactating Holstein dairy cows were used from -4 to 8 wk relative to calving (0 wk: the calving week). Endometrial samples were obtained sequentially from 2 to 8 wk. Body condition score and backfat thickness were obtained weekly from -4 to 8 wk. Blood samples collected from -4 to 8 wk were analyzed for indicators of energy status, hepatic function, systemic inflammation, and calcium. Blood amino acids were measured at 2 wk. Daily milk production was determined between 5 and 65 d postpartum. Based on the sequential cytological analysis, the endometrial inflammation threshold was set at ≥5.0% PMN, and the median wk of PMN% lower than 5.0% was 4.5 wk in this study; therefore, we classified the cows into the early group (cows with endometrial inflammation converged within 4 wk: n = 17) and the late group (cows with endometrial inflammation converged at or after 5 wk: n = 16). There were no differences in daily milk production, energy status, hepatic function, blood calcium concentration, and systemic inflammatory response. The late group had lower body condition scores and backfat thickness during the experimental period, and a higher blood concentration of 3-methyl histidine, indicating muscle breakdown, was observed in the late group at 2 wk. Our findings indicated that the lack of body fat reservation during the peripartum period and the increased muscle breakdown after calving were risk factors for prolonged endometrial inflammation.
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Vet Immunol Immunopathol., Dec, 2021 Peer-reviewed
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Parasitology International, 86 102476-102476, Oct, 2021Trypanosoma theileri is considered a non- or low-pathogenic trypanosome that generally causes latent infection in apparently healthy cattle; however, T. theileri propagates in the bloodstream and may cause clinical disease in pregnant animals or co-infection with bovine leukemia virus or Theileria orientalis. In the current study, a monthly survey of T. theileri infection over one year was carried out in a research dairy farm in Hokkaido, Japan to determine the 1) seasonal variations in the prevalence, 2) genetic characterization of T. theileri, and 3) associations of milk and blood parameters in dairy cattle with T. theileri infection, including data of metabolic profile tests and dairy herd performance tests, using linear mixed models. We found that 1) the prevalence of T. theileri infection was significantly higher in summer and winter than in other seasons; 2) T. theileri possibly showed genetic diversity in Eastern Hokkaido; and 3) T. theileri infection was associated with significantly lower levels of blood urea nitrogen, milk protein, and solids-not-fat, which are caused by a low rumen fermentation level. This is the first study to report the negative impact of T. theileri infection in dairy cattle, and our study indicates that control of T. theileri infection can improve the productivity of dairy cattle.
Misc.
54Presentations
117-
令和5年度 畜産技術情報収集・提供事業 第2回畜産技術研修会―超音波画像診断装置を用いた繁殖検診―, Dec 13, 2023 Invited
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令和5年度 畜産技術情報収集・提供事業 第2回畜産技術研修会―超音波画像診断装置を用いた繁殖検診―, Dec 12, 2023 Invited
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令和5年度獣医師能力向上・就業支援・地域獣医療体制整備支援事業「新規獣医師が基礎的な臨床技術を修得するための技術研修」, Dec 8, 2023 Invited
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International Conference on New Trends in Applied Sciences (ICONTAS'23), Dec 2, 2023
Teaching Experience
7Professional Memberships
2Research Projects
9-
特別振興資金助成事業, 日本中央競馬会, Apr, 2022 - Mar, 2025
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科学研究費助成事業, 日本学術振興会, Apr, 2021 - Mar, 2024
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Grants-in-Aid for Scientific Research, Japan Society for the Promotion of Science, Apr, 2021 - Mar, 2024
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一般財団法人 旗影会 助成金, 一般財団法人 旗影会, Apr, 2020 - Mar, 2021
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伊藤記念財団 令和2年度研究助成, 公益財団法人 伊藤記念財団, Apr, 2020 - Mar, 2021