Obihiro University of Agriculture and Veterinary Medicine
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多機能超音波画像診断によるセラピーホースに適した馬の妊娠および胎子検査
Get PDF帯広畜産大学博士（獣医学）Doctor of Veterinary Medicine2023application/pdf北海道和種馬は日本において重要な動物である。保有数が年々減少する現状の中で、如何に保護するのが重要な課題の1つである。生産性向上の要として、流産防止は馬繁殖効率向上の一番の課題である。そのため、本研究は北海道和種馬妊娠馬に関する研究に着目し、第1章から第3章までの実験を行った。この研究を通じて、より効率的な北海道和種馬の生産を可能とすることを目標とした。
第1章では、北海道和種馬の正常妊娠時の胎子健康指標を計測した。妊娠時胎子のFEO、CTUP、FHR、FGL、FKL並びに妊娠馬の血中ホルモン測定は胎子評価の大事の指標である。後程の第3章においてもその重要性を表してる。また本実験における最大の発見は胎子性腺の大きさと母体E2濃度の相関が発見したことである。この結果から妊娠中の妊娠維持のためのE2産生メカニズムと胎子性腺との関係が更に明らかになった。
第2章では、初めて馬を用いて3D超音波検査を使用し、妊娠早期胎子性別判断を行った。馬においての生前胎子性別判断は従来ほとんど2D超音波検査を使用したが、本実験から、2D超音波検査より3D超音波検査は性別判断が容易になり、更に2D超音波検査より10日早めに性別判断が出来ることが判明した。将来3D超音波検査はより有用な胎子性別判断法として期待できる。
第3章は馬胎子巨大膀胱の症例報告である。馬の巨大膀胱は非常に稀な症例であり、この章では、馬胎子巨大膀胱の妊娠全期間の経過、胎子指標および母体ホルモン変化を詳細に記録した。この症例から得られたデータは将来馬胎子巨大膀胱の診断に有用と思われる。また本症例の観測はほとんど経腹壁超音波検査のみ可能であるため、改めて妊娠後期の経腹壁超音波検査の重要性も重視すべきと思われる。
最後に以上の実験から、更に北海道和種馬の妊娠に関する知見が深まり、将来的な北海道和種馬の生産に役立つこと、また、この知見を他の保有数の少ない馬でも応用できることが期待される。The Hokkaido Native Pony is one of the eight native Japanese Native horse breeds that live in Japan. The Hokkaido Native Pony is 120-130 cm in height and has a mild temperament, making it suitable for horse-assisted therapy. However, the number of Hokkaido Native Pony is decreasing year by year. In addition, little research has been conducted on the breeding of Hokkaido Native Pony.
Ultrasound imaging is an important tool in the examination of equine reproduction. In order to improve the breeding efficiency of Hokkaido Native Pony, this study was conducted to investigate fertility in Hokkaido Native Pony using multifunctional ultrasound technology by conducting Experiments 1-3.
Experiment 1 measured fetal well-being parameters in normal Hokkaido Native Pony for the whole gestation period.
Embryo transplants were performed on 5 Hokkaido Native Pony and crossbreds from 2018-2020, totaling 7 gestational periods. Examinations were performed every week using an ultrasound imaging system to measure uteroplacental thickness (CTUP); fetal eye orbital length (FEO); gonadal length (GL); and fetal heart rate (FHR) through the rectal or abdominal wall using linear and convex probes.
FHR reached a peak of 180 ± 6.3 beats/min from 9-13 weeks of gestation and then decreased until full-term; FEO could be measured from 10 weeks gestation and increased until full-term, reaching 35 ± 2.5 mm before delivery; CTUP could be measured from 13 weeks of gestation and increased until fullterm, reaching 8.6 ± 0.6 mm before delivery; and GL was measured from 9 weeks of gestation and increased until full-term. GL was measurable from 16 weeks of gestation to full term and was peaked at 27-37 weeks of gestation, then decreased until full term.
FHR has the ability to detect fetal abnormalities such as fetal acid deficiency and cardiovascular system stunting, CTUP was used for ascending placentitis, and FEO was reported to be useful as a simple indicator of fetal development. In addition, GL was found to be consistent with estradiol secretion dynamics, which is important for the maintenance of pregnancy. This experiment will enable early detection of pregnancy abnormalities in Hokkaido Native Pony and is expected to improve equine productivity.
Experiment 2 used 3D ultrasound to determine the fetal gender of pony in early pregnancy.
A total of 9 pregnancies of 5 Hokkaido Native Pony were performed from 2020 to 2023. Fetal gender determination was performed once every 5 days between 50 and 100 days of gestation. At the time of examination, the fetal was first determined by transrectal examination with a linear type probe. Then, the probe was replaced with a 3D probe of the convex type, and the subabdominal region of the fetal was moved to the center of the screen. The fetal 3D volume was scanned three times when mares were at rest and then analyzed posteriorly.
Results showed that all 2D and 3D examination results were consistent with postpartum fetal sex. The gestational age at which fetal gender could be determined by 2D and 3D ultrasound ranged from 50 to 80 days of gestation. For 2D ultrasound, the highest detection rate was at 70 days gestation (66.7%). For 3D ultrasound, the highest detection rate was 60 days (55.6%).
Fetal gender determination in pregnant horses is a technique of enormous benefit. This experiment was the first study to evaluate the utility of 3D ultrasound fetal gender determination in pony. In this experiment, all fetal 3D ultrasound images from gestation 50 to 100 days were feasible. The advantage of 3D ultrasound is that it can scan the fetus without changing the angle of the probe during the examination, which is considered to be more accurate than 2D ultrasound.
Experiment 3 was a case report of early detection of fetal enlarge bladder by transabdominal ultrasound prenatal diagnosis.
The pregnant mare in this case was an 8-year-old Hokkaido Native Pony whose embryo was transferred from a Kiso-pony in Nagano on June 10, 2021, and arrived at Obihiro University of Agriculture and Veterinary Medicine on the same day. At 215 days of gestation, a low-intensity ultrasound image of a fetal abdominal abnormality was observed for the first time during transabdominal ultrasound examination. Subsequently, at 229 days of gestation, it was determined that the abnormal image was the bladder, based on its position in relation to the other organs. Thereafter, the abnormal bladder was visible until delivery, and its volume increased as the pregnancy progressed.
Since the fetus did not appear to give birth until 30 days past the due date, delivery was induced at 363 days of gestation, and a live foal was born. The foal was euthanized without treatment due to congenital defects other than a enlarge bladder.
This was the first case in which a giant bladder in a fetal was observed during prenatal diagnosis, and the fetal was subsequently born alive. In this case, the fetal enlarge bladder was found to have no effect on other health parameters. Surprisingly, the fetal was born alive without bladder rupture. Thus, the enlarge bladder in equine fetal can be detected by ultrasonography even at the gestational stage. Compared to the fatal that not be examined prenatally, the treatment can be performed more quickly and precisely. On the other hand, in the clinical enlarge bladder can also be associated with hydronephrosis. In the present case, the kidneys were not abnormal until delivery. Further studies are required to clarify the mechanism of enlarge bladder complications. Finally, although there are still many unclear issues regarding equine congenital diseases, widespread prenatal examination of equine fetal can be expected to increase the survival rate of equine fetal by identifying the condition of the fetal at the gestational stage and preparing for treatment of fetal abnormalities before delivery.
The data collected in this study is expected to be fundamental research that can contribute to improving the productivity of Hokkaido Native Pony in the future.博士学位論文大学院畜産学研究科 獣医学専攻Doctoral Program of Veterinary Sciencedoctoral thesi
馬の選択的卵管通水法に関する研究
Get PDF帯広畜産大学博士（獣医学）Doctor of Veterinary Medicine2023application/pdfサラブレッド種は個々の経済的価値が高いため、生産性を向上させることは意義深い。生殖器疾患の診断および治療技術が年々進歩するに従い受胎率も向上してきたが、依然として原因不明の不妊症に遭遇する。
馬の卵巣や子宮に関しては比較的アプローチが容易であり、その部位が原因となる不妊症に対する診断や治療方法は改善されてきた。卵管の剖検所見ではコラーゲン塊が内在している症例が多く、その大きさによっては卵管の疎通性を障害し不妊の原因となり得ることが示唆されている。しかし、卵管性不妊に対する臨床的な診断、治療方法は確立されていない。これは馬の卵管子宮口は解剖学的に乳頭状に突出していて、発達した平滑筋により開口部が緊縮しているため、子宮腔から卵管内へのアプローチが困難であることに起因している。
一方、人の婦人科医療では子宮鏡観察下で卵管にカテーテルを留置し、卵管の疎通性を診断するための選択的卵管通水法が確立されている。
本研究の第2章では、大腸ファイバースコープによる観察下で子宮腔内から卵管子宮口に挿入可能なカテーテルを作成し、馬において内視鏡観察下で選択的卵管通水法が可能であるか検討した。その結果、作成したカテーテルは高い確率で卵管子宮口に挿入することが可能であり、そのカテーテルを通じて卵管内に色素を注入すると卵管やその周辺組織が着色したこと、また卵管采より漏出した色素により腹水が着色した症例があったことから、馬の卵管の疎通性を評価し得ることが判明した。
第3章では、第1章で確立した卵管通水法を用いて, 既存の診断方法では異常所見が認められない不妊馬において, 多くの剖検所見で認められる卵管内のゼラチン塊による卵管閉塞に起因して不妊症が発症していると仮定し, その細胞塊を卵管子宮口からの生理食塩水による通水で腹腔内に押しやることで卵管の再疎通を試みた。その処置後の受胎率を調べることで, その卵管通水法が妊孕性の改善に有効であるか検討した。その結果、内視鏡観察下で卵管子宮口にカテーテルを挿入し, 生理食塩水を通水する卵管通水法は, 卵管閉塞が疑われる不妊馬に対し受胎率を著しく向上させることができることが判明した。
本研究で開発された選択的卵管通水法は斬新であり、子宮腔内から卵管に非侵襲的に通水することが可能となったことから、今までほぼ不可能であった卵管性不妊を有する症例に対し、臨床的にその診断や治療に寄与できる方法を確立し得ることが示された。将来的には、卵管授精の確立や卵管機能の研究等を進展させる一助となり、馬の生産率向上に大きく貢献できることが示唆された。Because of the high individual economic value of Thoroughbred horses, it is significant to improve their productivity. Although the fertility rate has been improved as the technology for diagnosing and treating reproductive diseases was progressed year by year, infertility of unknown causes is still encountered.
The ovaries and uterus of mares are relatively easy to approach, therefore, the diagnosis methods, especially ultrasonography, and treatment for infertility caused by the ovaries and uterus have been improved in recent years. On the other hand, clinical diagnosis and therapeutic methods for tubal infertility have not yet been established. This is because the uterotubal junction has a papilla-like structure and is constricted by well-developed smooth muscle in mares, making it anatomically difficult to approach the uterine tubes from the uterine cavity. However, autopsy findings show that collagenous masses are present in the uterine tubes in many cases. It has been suggested that depending on the size of the collagen masses, the patency of the uterine tubes may be impaired and that could be potential cause of infertility. In the past reports, most of researchers have attempted tubal cannulation through the fimbria by invasive methods using laparotomy or laparoscopy for suspected tubal infertility.
Compared to the anatomical structure of the uterine tube in horses, the human uterotubal junction does not have contracted smooth muscle and may open into the uterus, so that it is relatively easy to access into the uterine tube from uterine cavity. In human gynecological medicine, a selective hydrotubation has been established for diagnosing the patency of the uterine tubes by placing a catheter in the tubes under hysteroscopic observation.
In Chapter 2, which follows Chapter 1 (the introduction of this research), a catheter that can be inserted from the uterine cavity into the uterine tube under endoscopic observation through the working channel of a video endoscope was prepared using a polyethylene tube, an outer tube of an indwelling catheter and a guide wire for human angiography. Then 10 experimental mares were restrained in stocks and sedated, and a video endoscope was inserted into the uterus from the vulva. It was attempted to insert the catheters into the uterotubal junction at both uterine horns and dye was infused into the uterine tubes. After this procedure, abdominal fluid was obtained to identify color of the stain. In addition, a partial incision was made in the vaginal wall and another endoscope was inserted into the abdominal cavity to observe the ovaries, uterine tubes, and surrounding tissue directly. We investigated whether selective hysteroscopic hydrotubation is possible in mares by these procedures. As a result, the created catheter could be inserted into the uterotubal junction with a high probability and the dye solution was observed in the ampula and on surrounding tissue. In addition, peritoneal fluid was stained by the dye solution which could be leaked from the fimblia in some cases. From this result, it was clarified that hydrotubation is possible and this technique could be a potential diagnostic tool for oviductal patency in mares.
In Chapter 3, in 28 mares with unexplained infertility, assuming the cause is that a relatively large gelatin mass presented in the uterine tubes interferes with the passage of sperm and/or fertilized eggs, using the hysteroscopic hydrotubation established in Chapter 2, recovery of the oviductal patency was attempted by pushing the collagenous mass into the peritoneal cavity with flushing saline through the uterine tubes from uterotubal junction. Success with cannulation, pregnancy rate after treatment were researched and it was evaluated that whether this treatment is clinically useful for improving fertility. As a result, catheterization into the uterotubal junction was possible with a high probability regardless of the stage of the estrous cycle, and the conception rate after the procedure showed a high value regardless of the number of matings that did not lead to conception before the procedure. From this result, it was clarified that the hysteroscopic hydrotubation using saline could remarkably improve the conception rate in infertile mares suspected of having oviduct blockage.
The selective hysteroscopic hydrotubation developed in this research is novel and making it possible to perform non-invasive treatment. In addition, it is significant that the collagenous mass blocking the lumen of the uterine tube could be expelled into the peritoneal cavity from the extremely narrow isthmus through the ampulla which has a relatively large lumen. This study revealed that it will be possible to establish a method that can clinically contribute to the diagnosis and treatment for infertility caused by oviductal patency in mares. It was suggested that in the future, this technique is potential to help to establish oviduct insemination and advanced research for oviduct function. Also, it will contribute to improve production rate of horses.博士学位論文大学院畜産学研究科doctoral thesi
Noninvasive measurement of blood calcium concentration using electrocardiography in peripartum Jersey cows
Get PDFapplication/pdfWe previously developed a noninvasive method for measuring blood calcium concentration (Ca) in Holstein cows on site using electrocardiographic (ECG) variables and calving number, based on a high positive correlation between Ca. Jersey cows easily develop peripartum hypocalcemia compared with other dairy cows. The early detection and treatment of hypocalcemia are particularly important for Jersey cows because delayed treatment can result in various complications. In this study, to establish a simple, noninvasive, on-site diagnosis of hypocalcemia in perinatal Jersey cows, we attempted to create an equation for estimating Ca using ECG waveforms. Overall, 112 Jersey cows 0–2 days postpartum were used. The ECG findings of these cows were measured using the base-apex lead for 30 s and the corrected ST interval (STc = ST peak interval/SS peak interval0.5) was calculated. Simultaneously, blood was collected from the tail vein, and the serum total Ca (tCa) and serum ionized Ca (iCa) were measured. Several items considered related to Ca were investigated. A strong positive correlation was observed between the tCa and iCa (r = 0.96). A positive correlation was observed between the tCa and STc−1 (r = 0.83). Furthermore, significant correlations were observed between skin temperature, calving number, vigor level, rumen movement, and auricle temperature (p < 0.05). Of these, multiple regression analysis was performed to calculate the tCa estimation formula with the STc and calving number (categorized into primipara, second parity, and third or more parity) as explanatory variables and the tCa as the objective variable (r = 0.85, p < 0.01). Of 15 postpartum Jersey cows, the estimation formula could mostly distinguish between cows with hypocalcemia, those with subclinical hypocalcemia, and normal cows. Blood Ca in peripartum Jersey cows can be noninvasively estimated using ECG variables and calving number. Copyright © 2023 Chiba, Nozaki, Itoh and Kawamoto.journal articl
Development and evaluation of specific polymerase chain reaction assays for detecting Theileria equi genotypes
Get PDFapplication/pdfBackground: Theileria equi causes equine piroplasmosis, an economically significant disease that affects horses and other equids worldwide. Based on 18S ribosomal RNA (18S rRNA sequences), T. equi can be classified into five genotypes: A, B, C, D, and E. These genotypes have implications for disease management and control. However, no conventional polymerase chain reaction (PCR) assays are available to differentiate the genotypes of T. equi. To overcome this limitation, we developed and evaluated PCR assays specific for the detection of each T. equi genotype. Methods: A pair of forward and reverse primers, specifically targeting the 18S rRNA sequence of each genotype, was designed. The genotype-specific PCR assays were evaluated for their specificity using plasmids containing inserts of the 18S rRNA sequence of each genotype. Subsequently, the assays were tested on 270 T . equi-positive equine blood DNA samples (92 from donkeys in Sri Lanka and 178 from horses in Paraguay). 18S rRNA sequences derived from the PCR amplicons were analyzed phylogenetically. Results: Each genotype-specific PCR assay accurately targeted the intended genotype, and did not produce any amplicons when 18S rRNA from other T. equi genotypes or genomic DNA of Babesia caballi or uninfected horse blood was used as the template. Previous studies employing PCR sequencing methods identified T. equi genotypes C and D in the Sri Lankan samples, and genotypes A and C in the Paraguayan samples. In contrast, our PCR assay demonstrated exceptional sensitivity by detecting four genotypes (A, C, D, and E) in the Sri Lankan samples and all five genotypes in the Paraguayan samples. All the Sri Lankan samples and 93.3% of the Paraguayan samples tested positive for at least one genotype, further emphasizing the sensitivity of our assays. The PCR assays also had the ability to detect co-infections, where multiple genotypes in various combinations were detected in 90.2% and 22.5% of the Sri Lankan and Paraguayan samples, respectively. Furthermore, the sequences obtained from PCR amplicons clustered in the respective phylogenetic clades for each genotype, validating the specificity of our genotype-specific PCR assays. Conclusions: The genotype-specific PCR assays developed in the present study are reliable tools for the differential detection of T. equi genotypes. Graphical abstract: [Figure not available: see fulltext.] © 2023, The Author(s).journal articl
シーベリーによる地域振興と消費者の潜在的需要
Get PDFapplication/pdfシーベリーは栄養価が高く，わずかではあるが日本でも北海道の一部で栽培されている。本稿では士幌町の取組事例からシーベリー商品を用いた地域振興の課題を整理するほか，消費者調査により潜在的需要について明らかにすることを目的とした。北海道の士幌町で栽培されるシーベリーはロシア産赤種であるが，実が柔らかく手摘みでしか収穫できないため栽培は困難であること，天候の影響を強く受けることが明らかになった。一方で，士幌町内の関係機関は，地域特産品として認知してもらうために，価格を安く提供し，幅広い年齢層に向けて商品開発を進めており，近年では供給よりも需要が大きい状況にある。消費者調査からは，シーベリーの認知度は著しく低く，そのイメージもほとんどないという結果が得られた。ただし，シーベリーに対する購入意欲は，スキンケア用品やサプリメントでは高く，消費者の求める機能性を打ち出しながら商品展開を行っていくことが必要と示唆された。Seaberries have high nutritional value and are cultivated quite limited volume in some parts of Hokkaido in Japan. The aim of this paper is to clarify the issues of regional promotion using seaberry products by the case study of Shihoro town and to analyze potential demand through consumer surveys. The seaberries grown in Shihoro, are a Russian red variety. It was found that cultivation is difficult because they are soft and can only be harvested by hand, and that they take a heavy damage by the strongly wind and rain. To position seaberry products as a local specialty, the relevant authorities in Shihoro town have offered them at a low price and accelerated the product development for a wide range of age groups. At a current situation, the demand was over the supply. Consumer surveys showed that awareness of the seaberry was significantly low and its image was almost non-existent. However, the willingness to purchase seaberries was high for skincare products and supplements. The results were suggested that product development should be carried out while setting out the functionality sought by consumers.departmental bulletin pape
おびひろ動物園のなかま 2023
Get PDFapplication/pdf世界の動物
家畜と愛玩動物
とかちの動物Animals around The World
Domestic Animals & Pet Animals
Wildlife in Tokachi「野生生物保全管理技術養成事業」の一環として作成された
https://www.obihiro.ac.jp/biodiversityjournal articl
Babesia ovis secreted antigen-1 is a diagnostic marker during the active Babesia ovis infections in sheep
Get PDFapplication/pdfOvine babesiosis caused by Babesia ovis is an economically significant disease. Recently, a few B. ovis-specific proteins, including recombinant B. ovis secreted antigen-1 (rBoSA1), have been identified. Immunological analyses revealed that rBoSA1 resides within the cytoplasm of infected erythrocytes and exhibits robust antigenic properties for detecting anti-B. ovis antibodies. This protein is released into the bloodstream during the parasite’s development. It would be possible to diagnose active infections by detecting this secretory protein. For this purpose, a rBoSA1-specific polyclonal antibody-based sandwich ELISA was optimized in this study. Blood samples taken from the naturally (n: 100) and experimentally (n: 15) infected sheep were analyzed for the presence of native BoSA1. The results showed that native BoSA1 was detectable in 98% of naturally infected animals. There was a positive correlation between parasitemia level in microscopy and protein density in sandwich ELISA. Experimentally infected animals showed positive reactions from the first or second day of inoculations. However, experimental infections carried out by Rhipicephalus bursa ticks revealed the native BoSA1 was detectable from the 7th day of tick attachment when the parasite began to be seen microscopically. Sandwich ELISA was sensitive enough to detect rBoSA1 protein at a 1.52 ng/ml concentration. Additionally, no serological cross-reactivity was observed between animals infected with various piroplasm species, including Babesia bovis, B. bigemina, B. caballi, B. canis, B. gibsoni, Theileria equi, and T. annulata. Taken collectively, the findings show that the rBoSA1-specific polyclonal antibody-based sandwich ELISA can be successfully used to diagnose clinical B. ovis infections in sheep at the early stage. Copyright © 2023 Sevinc, Zhou, Cao, Ceylan, Ulucesme, Ozubek, Aktas and Xuan.journal articl