• Korean Journal of Veterinary Research
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• v.35 no.1
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• pp.107-113
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• 1995

Four Holstein calves 7-day-old were infected with C parvum oocysts for parasitological and pathological investigations of bovine cryptosporidiosis. Of those calf 1 was orally administered with $7{\times}10^6$ oocysts of C parvum isolated from a Korean mouse (VRI-CN91), and calf 2 with same number of C parvum oocysts provided by Washington State University(WSU). The rest (calf 3 and 4) were orally administered with $1{\times}10^8$ oocysts of VRI-CN91 strain. Calf 1 commenced to discharge oocysts in feces at days 6 post inoculation(PI), and it reached a peak $1.4{\times}10^7$ oocysts per gram of feces(OPG) on day 8 PI. Calf 2 commenced to discharge oocysts in feces at day 4 PI, and it reached a peak $3.75{\times}10^6$ OPG on day 7 PI. Calf 3 and 4 commenced to discharge oocysts in feces at day 3 and day 4 PI, and it reached a peak on day 7 PI (calf 3, $7.8{\times}10^6$ OPG; calf 4, $1.7{\times}10^6$ OPG). Clinically, the calves began to show mucoid-watery diarrhea at day 3 to 5 PI, and the sign lasted 5 to 7 days. Calf 2 died on day 9 PI with a severe dehydration. On necropsy the intestine was found to be congested and hemorrhagic. Protozoan oocysts were observed mainly in the ileum and occasionally in jejunum. The results in the present study indicate that the Korean isolate was pathogenic in calves.

• Journal of Animal Science and Technology
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• v.63 no.5
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• pp.1114-1125
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• 2021

Supplying a sufficient amount of high-quality colostrum is a prevailing challenge in Hanwoo calf production systems. This study aimed to describe the efficiency of a lacteal-derived colostrum replacer versus natural bovine colostrum (from Holstein) fed to Hanwoo calves. Forty newborn Hanwoo calves (25 males and 15 females; 30.7 ± 3.15 kg body weight [mean ± standard deviation]) were blocked by sex and birth weight and fed either natural colostrum or a commercial colostrum replacer. Calves displayed a narrow difference in the evolution of body weight and structural body dimensions when they received a commercial versus natural colostrum. Minor differences existed in the starter and total dry matter consumption between calves fed natural or commercial colostrum. Although the colostrum source had no significant effects on days to first diarrhea (average of 7.6 days; p = 0.17), the duration of diarrhea was longer in natural colostrum-fed calves (3.2 vs. 4.5 days; p = 0.04). Consumption of natural colostrum resulted in greater mean serum immunoglobulin G (IgG) on day 2 (14.7 vs. 10.8 ± 0.92 mg/mL) and day 7 (8.21 vs. 5.12 ± 0.82 mg/mL) of calf life, resulting in a greater proportion of commercial colostrum-fed calves (50% vs. 15%; day 2) to experience failure of passive transfer of immunity (serum IgG < cutoff point of 10 mg/mL). Overall, growth rate, body frame development, and incidence of diarrheal disease were not different in both groups. These results suggested that the colostrum replacer product tested in this study could be an alternative to natural colostrum derived from Holstein cow in securing calf growth and health in Hanwoo calf-rearing operations.

• Korean Journal of Veterinary Service
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• v.35 no.4
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• pp.343-346
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• 2012

This study was investigated the effects of feeding the combination with Lactobacillus plantarum and Bacillus subtilis on the diarrhea incidence and fecal microflora of weaned calves. A total of 12 newly weaned calves were allocated to two dietary treatments in a randomized design based on body weight. The dietary treatments included a commercial basal diet supplemented with: 1) no microbial inoculants (Control); 2) a mixture of Lactobacillus plantarum and Bacillus subtilis (LB). Calves were fed diets for a 4-week period. At the end of the experiment, the counts of fecal lactic acid bacteria and Enterobacteriaceae in LB were significantly improved compared to control (P<0.05). Over the 4-week period, fecal scores and duration of diarrhea in LB were significantly decreased compared with those in control (P<0.05). The present results suggest that LB is a potential feed additive which could be used for the balance of intestinal microflora and the prevention of diarrhea in Korean native calves.

• Korean Journal of Veterinary Service
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• v.46 no.2
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• pp.147-156
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• 2023

Between February 2020 and September 2021, a total of 452 dairy calves with diarrhea were investigated across 17 dairy farms in Gyeonggi province, Korea, using a rapid diagnostic kit. The study aimed to examine the infection rates of major pathogens causing diarrhea in dairy calves, categorizing them by season, age, and birth month. Additionally, logistic regression analysis was conducted to investigate the factors affecting the infection rate. The infection rates of the major pathogens causing infectious diarrhea in dairy calves, including bovine rotavirus, bovine coronavirus, Cryptosporidium, and E. coli, are influenced by season, age, and birth month. Bovine coronavirus and Cryptosporidium showed variations in infection rates according to season, age, and birth month, while bovine coronavirus was influenced by age and birth month, and E. coli showed variations in infection rates based on age. Furthermore, in the analysis of risk factors influencing the infection rates of these pathogens, age and birth month were identified as risk factors for bovine rotavirus, bovine coronavirus, and Cryptosporidium.

• Korean Journal of Veterinary Research
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• v.54 no.4
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• pp.257-260
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• 2014

A calf suffering from diarrhea was admitted to the Animal and Plant Quarantine Agency for diagnostic evaluation. Postmortem examination revealed that the mesenteric lymph node was enlarged and small intestine wall was thin. Microscopically, a large number of small round organisms were attached to the small intestine villi. Villous atrophy and proprial neutrophil infiltration were also observed. Based on modified Ziehl-Neelsen staining, electron microscopy, and ELISA results, the calf was diagnosed with fatal cryptosporidiosis.

• Proceedings of the Microbiological Society of Korea Conference
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• 2005.05a
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• pp.227.1-227
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• 2005

• Korean Journal of Veterinary Service
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• v.20 no.2
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• pp.195-203
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• 1997

Fecal samples were collected from 47 calves with diarrhea and 12 clinically normal co-h-abitants, and tested for virus using MDBK cell cultures. Three cytopathic viruses were isolated from 8 fecal samples obtained from diarrheic calves. The isolated viruses were neutralized by bovine coronavirus hyperimmune serum In plaque reduction assay and were detected in the cytoplasm of MDBK cell by bovine coronavirus hyperimmune serum using immunofluorescence staining. The viruses agglutinated mouse erythrocytes only among the various animal erythrocytes tested and new isolates were identified as bovine coronavirus.

• Korean Journal of Veterinary Research
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• v.27 no.1
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• pp.69-76
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• 1987

An epizootic of calf diarrhea occurred in an extensive dairy farm located in Gangwondo province in December of 1985. The patients showing fever, chills, complete anorexia and watery diarrhea sometimes dysentery were concentrated among the calves ranged from 8 days to 3 months old and many of them died in acute course. The five carcases were examined by pathological and bacteriological means. The predominant gross lesions were edematous swelling of the mesenteric lymph nodes, profuse catarrhal or diphtheritic enteritis and extensive purulent bronchopnenomonia or lobar fibrinous pneumonia. Microscopically the lesions of the liver and spleen were characterized by coagulative necrotic foci and granulomatous nodules. The spleen and lymph node showed also proliferative changes of reticular cells and involution of intestinal lymphatic nodules were noticed. The strains of Salmonella(S) species isolated from the liver, spleen, bile juice, peritoneal fluid and thoracic fluid were identified serologically as S. dublin. These clinical and pathological findings of the disease were those of acute enteritis form of salmonellosis and characterized by high morbidity and mortality among the calf herd. The report also signifies the first description of an epizootic of bovine salmonellosis caused by S. dublin in Korea.

• Parasites, Hosts and Diseases
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• v.30 no.4
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• pp.259-262
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• 1992

This study was performed to investigate experimental transmission of Cryptosporidium parvum in a calf. A 25-day-old Korean native calf was inoculated per os with $1{\times}10^6$ C. parvum oocysts isolated from a Korean mouse. The calf commenced oocyst discharge in feces on post-inoculation day 4, and continued until the aah 11. The number of discharged oocysts Peaked($4.9{\times}10^5$) on post-inoculation day 6. However, the calf did not show signs of diarrhea. The present results indicate that C. parvum is cross-transmissible between the calf and the mouse.

• Journal of Veterinary Clinics
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• v.24 no.4
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• pp.588-592
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• 2007

The prevalence of E. coli(K99), Clostridium perfringens and Cryptosporidium parvum on acute diarrhea in suckling Korean native calves was evaluated in the field by a veterinary practice. In diagnosis, fecal samples were directly collected from calves that had diarrhea between 2 and 98 days of age. 40 samples were analyzed in October, 2006 and December, 2006. Clostridium perfringens and Cryptosporidium parvum were detected in 15(37.5%) and 4(10.0%) of the samples from diarrhetic calves, respectively. However, E. coli(K99) was not detected in the samples from diarrhetic calves. There was no significant difference(p>0.05) between October(5, 25.0%) and December(10, 50.0%) in incidence of detected Clostridium perfringens from diarrhetic calves. On the other hand, significant differences (p<0.05) in the detection rate of Clostridium perfringens were found between the within 1 month age and all other age groups. In the detection of Cryptosporidium parvum, there was no significant difference(p<0.05) between October (2, 10.0%) and December(2, 10.0%) in the incidence of detected Cryptosporidium parvum from diarrhetic calves. These results suggest that causative agents of calf diarrhea occurred frequently with Clostridium perfringens infection than E. coli(K99) and Cryptosporidium parvum.