• Journal of Microbiology and Biotechnology
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• v.19 no.5
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• pp.511-519
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• 2009

A chimeric gene encoding enhanced green fluorescent protein (EGFP) and a S-layer protein from Lactobacillus brevis KCTC3102, and/or two copies of the Fe-binding Z-domain, a synthetic analog of the B-domain of protein A, was constructed and expressed in Escherichia coli BL21(DE3). The S-layer fusion proteins produced in a 500-1 fermentor were likely to be stable in the range of pH 5 to 8 and $0^{\circ}C$ to $40^{\circ}C$. Their adhesive property enabled an easy and rapid immobilization of enzymes or antibodies on solid materials such as plastics, glass, sol-gel films, and intestinal epithelial cells. Owing to their affinity towards intestinal cells and immunoglobulin G, the S-layer fusion proteins enabled the adhesion of antibodies to human epithelial cells. In addition, feeding a mixture of the S-layer fusion proteins and antibodies against neonatal calf diarrhea (coronavirus, rotavirus, Escherichia coli, and Salmonella typhimurium) to Hanwoo calves resulted in 100% prevention of neonatal calf diarrhea syndrome (p<0.01), whereas feeding antibodies only resulted in 56% prevention.

• Journal of Veterinary Clinics
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• v.39 no.1
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• pp.38-43
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• 2022

A 5-month-old Holstein downer calf was presented, and bovine viral diarrhea virus was detected in the feces and the cerebrospinal fluid. Combined treatment of recombinant bovine somatotropin (rBST) administration and standing rehabilitation had been performed for two months, and the calf could maintain the standing position for a while. However, the symptoms were not improved, and the calf died due to ruminal tympany and aspiration pneumonia. Megaesophagus, abomasal ulcer, and a normal-sized but softened cerebellum were observed in clinical necropsy. Improvement of symptoms was confirmed by rBST, but was not reached the complete recovery of gait and standing position.

• Korean Journal of Veterinary Service
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• v.46 no.1
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• pp.47-58
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• 2023

Between February 2020 and September 2021, 378 calves with diarrhea were investigated across 96 cattle breeding farms in Korea, using a rapid diagnostic kit. The study examined the infection rates of major pathogens causing diarrhea in calves, which were categorized by season, age, birth month, and region. Additionally, logistic regression analysis was conducted to investigate the factors affecting the infection rate. The study found that the five representative pathogens causing calf diarrhea exhibited differences in infection rates based on season, region, age, and birth month. Bovine rotavirus, bovine coronavirus, Cryptosporidium, and Giardia commonly exhibited varying risks of infection based on season and age. Furthermore, in addition to these risk factors, bovine rotavirus and Cryptosporidium were found to impact the infection risk of each pathogen by region, while Giardia was found to be affected by birth month.

• Korean Journal of Veterinary Service
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• v.45 no.4
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• pp.293-304
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• 2022

Among several diseases of calves, diarrhea is the most prevalent disease and has been a major cause of economic loss to the cattle industry. The main etiologic agents of diarrhea in calves are bacteria, viruses, and protozoa, but non-infectious factors including foreign bodies obstruction in the digestive system also focused as the cause of calf diarrhea in the recent days. Because there is still limited information for foreign body-related diarrhea in calves, especially in Hanwoo, the present retrospective study reviewed the medical records for diarrheic calves with foreign body in the digestive system (n=32). The morbidity was determined as 3.03% and more than half of them presented the acidosis, hyponatremia, and azotemia. The mortality in laparotomy-operated calves to remove foreign bodies or in non-operated ones was 28% or 85.7%, respectively, implied the importance of aggressive decision for laparotomy when the foreign bodies were determined in the digestive system in diarrheic calves. During laparotomy, trichobezoars (hair balls) and hays were the main foreign bodies and prevalently placed in the abomasum. In the trials to predict prognosis by several clinical factors, the time for laparotomy over 2 days after first diagnosis, acidosis, and foreign body in the abomasum were highly associated with mortality. Therefore, we believe that prompt surgical procedure (laparotomy) is necessary upon obstruction in the digestive system by foreign bodies is tentatively diagnosed in the diarrheic calf. In addition, when differential diagnosis list is made, foreign body-related diarrhea is necessary to be included in case of diarrheic calf.

• Journal of Veterinary Clinics
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• v.39 no.6
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• pp.342-352
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• 2022

This study was conducted to identify the useful blood variables in diagnosing calf diarrhea in Hanwoo calves and good indicators for calf diarrhea. In 530 Hanwoo calves, fecal scores were recorded on a scale of 0 to 3, and blood samples were collected and analyzed for hematology, serum biochemistry, and acute phase proteins. Among the blood variables, 16 blood variables showed significant differences (p < 0.01) according to fecal scores. After reference intervals of these 16 blood variables were calculated, the distributions of calves by calculated reference intervals showed a significant difference (p < 0.001) and linear associations (p < 0.001) in blood urea nitrogen (BUN), glucose (GLU), blood sodium concentration (Na), blood potassium concentration (K), fibrinogen (Fib), and haptoglobin (Hp). Of 6 blood variables, the optimal cut-off values were calculated for BUN, K, Fib, and Hp, and the area under the curve was 0.5 or more: BUN (9.5 mg/dL, AUC: 0.623), K (5.8 mmol/L, AUC: 0.599), Fib (650.0 mg/dL, AUC: 0.706), and Hp (12.5 mg/dL, AUC: 0.847). These findings could be useful in evaluating calves with diarrhea and making decision of further treatment of calf diarrhea in Hanwoo calves.

• Korean Journal of Veterinary Service
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• v.30 no.1
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• pp.133-144
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• 2007

This study was conducted to determine the effective environmental control measures in preventing calf diarrheal disease in farms. It was found that the high numbers of calves in a cow house was directly related with the high incidence rate of diarrheal diseases. When the number of calves was increased in a cow house, it was difficult to reduce the diarrheal diseases of calves. It was revealed that the incidence rates of calf diarrheal disease were dramatically reduced when the delivery house which faced south. The periodical changes of bedding materials seemed beneficial good to control the possible resident infectious agents, including pathogenic viruses and bacteria. The control of the delivery time was important for reduction of calf diarrhea. It was revealed that September and October were the best time as the delivery period. In order to use old cow house as a delivery house, it should be sterilized by the disinfectant and the flame. When the diarrheal feces were removed as soon as possible, the transmission of diarrheal diseases among calves In the same house was reduced. When the diarrheal feces were not disposed, the incidence rate of diarrhea reached up to 50%. When the morbid calves were not quarantined, the incidence rate of diarrhea was 100%. In contrast, when the diseased calves were quarantined from other calves, the incidence rate of diarrhea was reduced, remarkably. The mean recovery time from the diarrhea of the treated calves in the southern cow house was much faster than that in the north cow house. The treatment of calves in a clean and well-ventilated cow house with dry bedding was more effective than that in a cold, wet, and dark house. It could be postulated that the most important environmental factor in the reduction of diarrheal diseases of calves is the blocking of the entry of the infectious agents. The complete sanitation and control of the delivery house in the using farm is more important than building a new cow house, for prevention of calf diarrheal diseases.

• Korean Journal of Veterinary Service
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• v.45 no.4
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• pp.337-342
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• 2022

Calf diarrhea is a major health concern in the livestock industry that requires accurate analysis for appropriate treatment. Dehydration and electrolyte imbalance are the most significant consequences of diarrhea in calves. Until now, the reference values of blood analysis of Hanwoo neonatal calves have not been well known. Recently, portable blood analyzers have made it possible to immediately analyze blood in the farm and provide suitable treatment for the patients. We analyzed electrolytes, blood urea nitrogen (BUN) and glucose in the blood of 179 Hanwoo neonatal calves, including 79 with diarrhea. These 179 calves were divided into 3 groups based on their age. Values of sodium (Na⁺ ) and glucose were significantly lower in diarrheic calves (1~30 days), while potassium (K⁺ ) and chloride (Cl^- ) values were higher in diarrheic calves (1~30 days). BUN values, which are closely related to dehydration due to diarrhea, increased in diarrheic calves of all ages. Therefore, these data can be used as reference values for blood analysis and treatment of healthy or diarrheic Hanwoo neonatal calves within 30 days of age.

• Korean Journal of Veterinary Service
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• v.21 no.2
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• pp.127-132
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• 1998

To study the efficacy monoclonal antibody(MAb) against bovine rotavirus(BCV) in treatment of calf diarrhea, the MAb was fed to 166 calves with diarrhea from Chung-buk area. The results were summarized as follows. 1. Among the 1,049 calves investigated, 166(16%) calves were infected with BCV. 2. The monthly rate of BCV infection were higher in October to December compared with other months of the year. 3. Among the 166 calves with diarrhea, 137(83%) calves were recovered. 4. Young calves within 7-day-old were more effective in treatment than other ages and the rate of treatment was 86% 5. Most effective period for treatment of rotavirus was at the first stage of infection.

• Korean Journal of Veterinary Service
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• v.40 no.1
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• pp.61-66
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• 2017

Calf diarrhea is a disease experienced by almost all of calves after birth and is one of the representative causes of damage to farmers due to mass mortality and of economic losses to them by inhibiting normal growth. In this study, we conducted quick detection of etiologic agents of diarrhea by using a rapid diagnostic kit to multiply diagnose antigens of five etiologic agents of calf diarrhea (rotavirus, coronavirus, Escherichia coli, Cryptosporidium, Giardia) in Hanwoo (Korean native cattle) calves. When the positive antigen proportion of the calf diarrheal feces for each farm was analyzed, rotavirus, coronavirus, Escherichia coli, Cryptosporidium, and Giardia showed antigen positive rates of 0~67%, 0~20%, 0~60%, 0~20%, and 0~67%, respectively. With regard to the antigen positive rate by age in days after birth, 1-week-old calves showed the antigen positive rate of 20% in rotavirus and 20% in Giardia, and 2-week-old calves showed that of 50% in rotavirus. In addition, 4-week-old calves showed the antigen positive rate of 10% in rotavirus, 10% in coronavirus, 10% in Escherichia coli, and 30% in Giardia, and 8-week-old calves showed the antigen positive rate of 17% in coronavirus, 50% in Escherichia coli, 17% in Cryptosporidium, and 33% in Giardia. Based on the results of this study, the etiologic agents of diarrhea in Hanwoo calves for each farm are widely distributed. Although younger than 2-week-old calves were strongly positive for rotavirus, older than 4-week-old calves were highly positive for Giardia and Escherichia coli. In conclusion, we considered that a rapid diagnostic kit is an effective method for quick detection of etiologic agents and would be helpful for cattle farmers and veterinarians to select appropriate therapeutic method.

• Korean Journal of Veterinary Service
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• v.35 no.4
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• pp.339-342
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• 2012

The objective of this study was to determine the infection patterns of etiological agents causing calf diarrhea in the Gyeongnam province, Korea. In this study, from January 2011 to December 2011, feces and necropsy specimens from 249 calves diagnosed with diarrhea (<7 months old) were examined by reverse transcriptase-polymerase chain reaction assay and bacteria & coccidium isolation for detection pathogenic organism. The results of this study showed that 78 cases (31.3%) in spring, 71 cases (28.5) in summer, 62 cases (24.9%) in fall and 38 cases (15.3%) in winter were diagnosed with calf diarrhea, respectively. Calf diarrhea-causing pathogens were diagnosed as bacteria 113 (45.4%), viruses 97 (39.0%), coccidium 1 (0.4%), unknown cases 13 (5.2%), and mixed infections 25 (10.0%). We isolated three virus types from fecal samples (97), which were classified as BVD 64 (66.0%), BRV 21 (21.6%), and BCV 12 (12.4%). Moreover, co-infected pathogens were 25 cases, consisting with BVD & BRV 11 (44%), BVD & BCV& BRV 7 (28.0%), E. coli & BCV 3 (12%), and BVD & IBR 1 (4.0%). In summary, we demonstrated that the enteropathogens of bacteria, viruses, and parasite were detected in samples from cattle with diarrhea, principally in young calves less than 7 months of age. Future studies of infectious diarrhea in cattle should include assays for this etiologic agent.