• Korean Journal of Veterinary Service
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• 제42권2호
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• pp.93-112
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• 2019

Calf diarrhea is a common disease in young claves and is still a major cause of productivity and economic loss in livestock farms. Fecal samples from Korean native cattle (n=100) with diarrhea from 64 farms in Gwangju area, Korea from september 2017 to December 2018 were examined for shedding of important protozoan parasitic, viral and bacterial pathogens using culture, rapid test kit and PCR methods. Of 57 (89.1%) of the 64 Korean native cattle farms examined had samples infected with at least one of the investigated pathogens. Among 100 fecal samples, 88 samples were positive for at least one the twelve pathogens and 51 samples were simultaneously positive for two or more pathogens by culture and PCR assay. Bovine group A rotavirus (BRV) was the most common pathogen, found in 43/100 (43.0%) samples on 32/64 (50.0%) farms. Subsequently, kobuvirus (30.0%), pathogenic E. coli (29.0%), bovine parvovirus (17.0%), Giardia spp. (13.0%), Eimeria spp. (10.0%), Clostridium perfringens type A (8.0%), bovine torovirus (8.0%), bovine viral diarrhea virus (6.0%), bovine coronavirus (5.0%), bovine norovirus (2.0%) and Cryptosporidium spp. (2.0%) were detected. Nebovirus, kırklareli virus, bovine adenovirus, Salmonella spp. and intestinal parasites were not detected. Of the 72 calves sampled in this age group, 64 (88.9%) samples were positive for at least one enteropathogen. BRV was identified in 34/72 (47.2%) samples from 27/48 (56.3%) farms. Subsequently, pathogenic E. coli (30.6%), kobuvirus (29.2%), BPaV (22.2%), Giardia spp. (15.3%), Eimeria spp. (9.7%), BVDV (6.9%), Cl. perfringens type A (6.9%), BCoV (4.6%) and Cryptosporidium spp. (2.8%) were detected in fecal samples. A total of ninety-six strains of E. coli were isolated from one hundred fecal samples collected from Korean native cattle with diarrhea. The presence of stx1, stx2, eaeA, LT, STa, STb, ehxA, saa, F4, F5(K99), F6, F17, F18 and F41 genes in the isolates was investigated by PCR. Out of ninety-six E. coli isolates screened for specific genes, 30 strains E. coli were identified to harbor shiga toxin-producing E. coli (STEC) 7 (7.3%), enterohemorrhagic E. coli (EHEC) 8 (8.3%), enteropathogenic E. coli (EPEC) 6 (6.3%), enterotoxigenic E. coli (ETEC) 2 (2.1%) and STEC/ETEC hybrid 7 (7.3%). This study provides epidemiological estimates of the prevalence of Korean native cattle's enteropathogens in Gwangju area, Korea, which would be used for cattle farmers and veterinarians to select appropriate therapeutic method.

• Korean Journal of Veterinary Research
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• 제34권2호
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• pp.229-235
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• 1994

The hemal nodes of the Korean native cattle were studied by gross anatomy and light microscopy. Hemal nodes were spherical or ovoid in shape, and red or black in colors. A hemal node consisted of a thick capsule and a hilum, and had extensive subcapsular and deep sinuses distended by a great number of erythrocytes. Although a few lymphatic nodules and tissues were seen in the parenchyma, no typical cortex and medulla was defined. Blood vessels occurred, but lymph vessel was not observed in nodes. The stroma of the hemal node was composed of reticular cells and fibers. The parenchyma consisted of many erythrocytes and lymphocytes, and a few macrophages and megakaryocytes. The capsule and trabecula was a collagenous connective tissue with smooth muscle cells. B-lymphocytes were principally located in the lymphatic nodules of the hemal node. T-lymphocytes were scattered in the diffuse lymphatic tissues of the hemal node.

• Korean Journal of Veterinary Service
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• 제46권4호
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• pp.283-291
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• 2023

Brucellosis and tuberculosis are major infectious and contagious bacterial diseases in cattle. These diseases are malicious diseases that must be inspected at the slaughterhouse of cattle in accordance with the practice of quarantine in Korea. Furthermore, both diseases lead to abortion, reproductive disorder, and calf disease, causing major difficulty in the breeding of Korean Native cattle (Hanwoo), a representative industrial animal currently being raised in Korea. Co-infections of these diseases intensify clinical symptoms such as abortion and have a particularly significant effect on increasing mortality. Thus, serological tests were performed in Hanwoo, to establish the association of co-infection between brucellosis and tuberculosis in cattle. ELISA and PCR tests were conducted on blood samples collected from a total of 102 cattle in Jeonnam province, Korea, to detect brucellosis and tuberculosis infections. The PCR results revealed that 41 samples tested positive for Brucella abortus (B. abortus) infection (40.20%), and 5 samples tested positive for Mycobacterium bovis (M. bovis) (4.90%) infection confirmed by PCR. Notably, 9.76% (4/41) of the cattle infected with brucellosis also tested positive for tuberculosis. In conclusion, this study highlights the co-infection of brucellosis and tuberculosis among Hanwoo cattle in Jeonnam province, which is expected to contribute to our understanding of disease transmission, pathogenicity, the establishment of future prevention strategies.

• Journal of Embryo Transfer
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• 제8권2호
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• pp.105-109
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• 1993

This study was carried out to propagate Korean native cattle using beef recipients by embryo transfer. Seven Korean native cattle donors were superovulated with FSH 32mg and Embryos collected from donors were frozen and preserved in National Animal Breeding Institute. Frozen-thawed embryos were transferred to synchronized 40 beef recipients nonsurgically in Daekwanryeong Branch of National Animal Breeding Institute. The results obtained were as follows : 1. Total ova and transferable embryos per donor were 11.4 and 11.1 from 7 donors, respectively. 2. Among 40 recipients transferred with frozen-thawed embryos, 20 were pregnant(50.0%). 3. The pregnancy rate according to time from embryo thawing to transfer was higher when transferred within 3 hours than after 3 hours(57.6% vs. 14.3%). 4. The cow recipients showed slightly higher pregnancy rate than the heifer(53.3% vs. 48.0%). 5. Two grade embryos showed higher pregnancy rate than 1 grade(66.7% vs. 45.2%).

• Journal of Embryo Transfer
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• 제9권1호
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• pp.43-48
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• 1994

This study was carried out to produce monozygotic twin calves by transfer of bisected embryos. Four Korean native cattle donors were superovulated with FSH and flushed to collect embryos on day 6 or 7 of the estrus cycle. Morula and early blastocyst embryos showed 1 or 2 grade were bisected with microblade and each set of demi-embryos without zona pellucida were transferred nonsurgically to 10 recipients respectively. The results obtained were as follows; 1. Twenty four demi-embryos (92.3%) were separated from 13 original embryos and among them 20 demi-embryos (83.3%) had normal appearance without severe damage. 2. Four sets of fresh demi-embryos were transferred to 4 recipients and one recipient was twin pregnant 3. Six sets of frozen-thawed demi-embryos were transferred to 6 recipients. Two recipients were pregnant, one of them twin.

• Journal of Embryo Transfer
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• 제11권2호
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• pp.137-144
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• 1996

The present study was carried out to obtain the pregnancy and delivery rate following transfer of fresh and frozen-thawed Korean native cattle(KNC) blastocysts(1~4 em-bryos / head) produced in vitro to Holstein recipients. The pregnancy rate of fresh and frozen-thawed KNC blastocysts produced in vitro was 50%(7 /14 heads) and 38.5%(5 /13 heads), respectively. The pregnancy rate of frozen-thawed KNC blastocysts produced in vitro frozen using 1.5M ethylene glycol and 1.4M glycerol for cryoprotectant was 33.3%(2 /6 heads) and 42.9 %(3 /7 heads), respectively. Seven calves including 2 sets of twin were born fiom 5 pregnant recipients receiving eleven fresh blastocysts. Three pregnant recipients were aborted among four pregnant recipients receiving twelve frozen-thawed blastocysts and one calf was born from the rest of one pregnant recipient.

• Asian-Australasian Journal of Animal Sciences
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• 제14권12호
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• pp.1763-1768
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• 2001

The combined effects of low voltage electrical stimulation (ES) and early short-term temperature conditioning on meat quality of Hanwoo beef (Korean native cattle) during storage were investigated. Shear force was influenced by ES and aging. Combination of ES and the $30^{\circ}C$ conditioning resulted in higher myofibril fragmentation index and improved lightness. There was no substantial difference in drip loss among treatments but ES samples showed higher cooking loss than control. Negative effect on shelf-life was not found by early short-term high temperature conditioning. Therefore, the meat quality of Korean native cattle was effectively improved by the combination of ES and the $30^{\circ}C$ conditioning.

• Korean Journal of Veterinary Service
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• 제27권1호
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• pp.53-62
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• 2004

The present study was carried out to investigate the prevalence of Neospora caninum infection in Korean indigenous cattle and calves of abnormal deliveries and focus on correlation between malformation and N caninum infection. To determine the prevalence of antibodies to N caninum, sera of 473 Korean indigenous cattle from slaughter house were tested for N caninum antibodies using indirect fluorescence assay. Of the 473 cattle sera, 9.5% (45/473) showed positive against N caninum. Regional seropositive rates of the samples were 16.7% (5/85), 11.0% (11/100), 8.8% (21/240) and 5.9% (5/85) at Kyonggi, Gyeongbuk, Daegu and Kyongnam province, respectively. In female, seropositive rates were 17.5% (25/143) and 6.1% (20/330) in male. During the period from march 2000 to August 2001, 55 abnormal deliveries of Korean indigenous cattle including abortion, stillbirth and congenital malformation were examined by histopathological, immunohistochemical and serological methods for evidence of N caninum infection. Of the 55 abnormal deliveries, only 5 calves showed positive reaction against N caninum in serological test. In microscopical observation, gliosis and nonsuppurative myositis were observed. However, Neospora-like organisms were not detected by either periodic acid-schiff (PAS) reaction or immunohistochemical technique. Taken together all these data, this study indicate that N caninum infection was widespread in breeding farms of Korean native cattle, but correlation between malformation and N caninum infection was not recognized.

• Korean Journal of Veterinary Service
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• 제45권2호
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• pp.133-137
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• 2022

Lumpy skin disease (LSD) is a severe cross-border infectious disease that causes fever, skin and visceral nodules in cattle. LSD is caused by the lumpy skin disease virus (LSDV), a dsDNA virus that belongs to the genus Capripoxvirus. Although LSD has been found only in Southern Africa traditionally, in the last decade it is spreading very quickly through the Middle East and into Eastern Europe and China. It usually affects cattle and water buffalos being transmitted by blood-feeding insects. As it causes a huge economic impact, LSD is a notifiable disease by World Organisation for Animal Health, and managed as the legal infectious disease class I in Korea. Therefore, the purpose of this study was to confirm the existence of LSDV antigens or antibodies in Korean livestock. We collected 1,200 blood samples from cattle (Korean native and dairy cattle) and Korean water deer in 4 major provinces of the country, then tested the existence of LSDV antigen and antibody. None (0.0%) of the 1,200 blood samples were positive for both antigen and antibody of LSDV. To the best of our knowledge, this is the first study that examines the prevalence of LSDV in Korea. Our study aims to report the LSDV occurrence situation obtained by surveillance in Korea and provide information that may help prevention of LSD epidemics.

• Korean Journal of Veterinary Research
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• 제42권4호
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• pp.437-442
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• 2002

The observations of the anatomical closure of the ductus venosus (DV) and vestige of DV were studied in 22 cattle, ranging from 210-day-old fetus to 3-years old Korean native cattle. Vinylite solution was injected into the hepatic, portal, umbilical veins and caudal vena cavae of 22 specimens for vinylite corrosion casts. The DV originated at the confluence of the umbilical and portal veins and emptied into the left hepatic vein or posterior vena cava. The DVs were persisted in a 210-day-old fetus, a 240-day-old fetus, and a 270-day-old fetus. Two newborns, two 2-year-old and two 3-year-old cattle had no rudimentum of DV (6 cases, 31.58%). However, vestiges of DV in varying sizes were observed in a 14-day-old, a 3O-day-old, two 180-day-old and nine adult cattle (13 cases, 68.42%). The lengths of vestiges of DV were about 4.97~99.66 mm. Therefore, the present study demonstrates that DV in cattle can be degenerated during the late period of a pregnancy.