• Journal of Practical Agriculture & Fisheries Research
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• v.16 no.1
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• pp.105-113
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• 2014

Equine herpesvirus type 1 (EHV-1) is an economically important pathogen of horses and exerts its major impact by inducing abortion storms and sporadic abortions in pregnant mares, early neonatal death in foals, and respiratory disease in young horses. Although equine herpesvirus type 4 (EHV-4) rarely causes clinical manifestations of disease in organs other than the respiratory track, isolated cases of myeloencephalopathy and sporadic abortions have been reported in EHV-4 infections. Here, we report an abortion storm in Thoroughbred breeding farms in Jeju island, South Korea. It occurred for 16 days from first abortion to last one. There were no clinical signs prior to abortion and stillbirth in broodmares. Two PCR-primers were made on glycoprotein B gene of EHV-1 and EHV-4 to amplify specific common regions of the viruses. We could detect the virus specific genes in aborted samples by PCR, and concluded that the cause of abortion storm was EHV infection. This report describes the first abortion storm case caused by EHV in Thoroughbred breeding farms in South Korea.

• Journal of Embryo Transfer
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• v.22 no.2
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• pp.97-100
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• 2007

The objective of the present study was to investigate relationships between Caslick's index and fertility for different age groups of Cheju mares. Ninety-one Cheju mares were used for this study. Caslick's index was measured the effective length and angle of declination of the vulva in the mare. They were mated naturally by stallions from February to October during the years $2002{\sim}2005$. The classification used in the present study was : Group I - good conception every years, Group II - conception every other year and Group III - Barren. Younger aged group ($3{\sim}7$ years) had a lower Caslick's index (<50) compared with $8{\sim}14$ aged group and older aged group (> 15 years). In this study, Caslick's index was increasing by increasing age of Cheju horse like Thoroughbred. However, fertility was decreasing by increasing Caslick's index. Hence, there was significant association between the different Caslick's index and fertility. Further research is needed to determine relationship between different Caslick's index and endometritis.

• Journal of Animal Science and Technology
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• v.64 no.4
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• pp.792-799
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• 2022

Dopamine (DA) is known to be a key modulator of animal behaviors. Thus, the plasma concentration of DA might be used as a biomarker for the behavioral characteristics of horses. The behavioral characteristics of horses vary depending on the breed, age, and sex. Moreover, the DA receptor genotypes are also related to horse behaviors. Thus, the aim of this study was to investigate the DA concentration variations of horse plasma by breed, age, sex, or genotype of its receptor. The horses were divided by breed into Thoroughbred (n = 13), Pony (n = 9), Warmblood (n = 4), and Haflinger (n = 5). The age variable was divided into three different groups: post-pubertal (2-5 years, n = 6), adult (6-13 years, n = 19), and aged horses (15-24 years, n = 6). The sex variable was divided into geldings (n = 8) and mares (n = 23). Approximately 10 mL of blood was collected, and an ELISA kit was used to measure the plasma concentration of DA. Polymerase chain reaction analysis was performed to identify the genetic variation in the DA D4 receptor gene (DRD4). SPSS statistical software was used for statistical analysis. The DA concentrations in geldings were significantly lower than those in mares. There was no significant difference in DA concentrations among breed and age groups. Horses with the GG and GA genotypes had significantly higher plasma concentrations of DA compared to horses with the AA genotype for the G292A gene. Briefly, the plasma concentration of DA varied depending on the sex and genotype of G292A. These factors should be considered when the concentration of DA is used as a biomarker for the behavioral characteristics of horses. In conclusion, the DA concentration or DRD4 genotype of horse plasma has the potential to be used as a biomarker that can predict the behavioral characteristics of horses.

• Journal of Life Science
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• v.20 no.5
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• pp.649-654
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• 2010

A total of 68 samples were collected including vaginal mucosa (n=66) from Jangsu stud farm, an equine aborted fetus (n=1), and uterine contents (n=1) from Jeju island. Seventeen Streptococcus equi subsp. zooepidemicus (S. zooepidemicus) strains isolated from horses in Korea were identified as S. zooepidemicus by biochemical tests and sodA.seeI specific multiplex PCR. All isolated strains were divided into 4 clusters: group 1 (No. 2, 3, 5, 6, 7, 11, 12, 13, 14, 15), group 2 (No. 4, 9), group 3 (No. 10, 16, 17), and group 4 (No. 1, 8) by RAPD typing. In group 3, No. 10 isolate that was isolated from vaginal mucosa was indistinguishable from No. 16 and 17 isolates, which were isolated from the equine uterine contents and the equine aborted fetus, respectively. The results of this study suggest that a limited epidemiological relationship exists between the strains from Jangsu (No. 10) and Jeju (No. 16 and No. 17). All isolates showed a high susceptibility to ampicillin, cefoxitin, ceftiofur, cephalothin, florofenicol, gentamicin, nalidixic acid, oxacillin, penicillin, tiamulin, tylosin and vancomycin in antimicrobial susceptibility tests. These results may provide the basic information needed to establish strategies for the treatment and prevention of reproductive diseases in mares in Korea.

• Journal of Embryo Transfer
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• v.32 no.3
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• pp.177-182
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• 2017

This study was conducted to investigate the ovarian cycle changes of the mare according to the season. Twenty four Jeju crossbred horses(Thoroughbred ${\times}$ Jeju horse) raised in Subtropical Livestock Research Institute, National Institute of Animal Science, RDA were used to identify follicles and corpus luteum with ultrasonography once a week(May 2016~June 2017). Blood samples of experimental horses were collected twice a week for analysis of P4 hormone levels. The mares were considered to have resumed ovarian cyclicity on the day of ovulation if they followed by regular ovarian cycles. Only 13 cases(61.9%) of the total 21cases showed normal ovarian cycle, and 8 cases (38.1%) showed delayed ovarian cycle. Three cases(16.7%) in October, 5 cases(27.8%) in November and 5 cases(27.8%) in December(27.8%) ceased the heat and the remaining 5 cases(27.8%) showed that the estrus was maintained in winter. Horses that stopped estrus ceased the heat until March of next year, and 27.8% were continued the heat during non-breeding season. Eleven cases(61.1%) of 18 cases in April and 2 cases(11.1%) of 18 cases in May returned the estrus.