• 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.

• Journal of Practical Agriculture & Fisheries Research
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• v.10 no.1
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• pp.201-205
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• 2008

For the prevention of Hanwoo calf diarrhea, the floor in a cattle shed was flamed using liquefied petroleum gas (LPG) in an attempt to substitute for the chemical disinfection method. Before flaming, litter on the floor was removed and cleaned. Outbreak rate of diarrhea in calves vaccinated with ScourGuard 3K^® was decreased from 70% to 30% and the effect of the flame disinfection lasted for three to four months.

• 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.43 no.3
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• pp.161-165
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• 2020

In order to effective treats a sick calf, it is necessary to obtain accurate information about the patient's condition. However, the standard references for Korean cattle claves are not well known. Therefore, this study aims to present useful clinical values by analyzing normal blood and diarrhea blood of Hanwoo calf. Recently, with the advent of a portable blood analyzer, it is possible to immediately analyze the patient's condition and severity in the field, not in the laboratory, and to calculate a suitable dosage for supporting fluid therapy. Therefore, in this study, the distribution of red blood cells (RBC) and white blood cells (WBC) were analyzed in normal and diarrhea Hanwoo calves. As a result, Hematocrit (HCT) levels increase significantly between 1 and 20 days in diarrhea positive calves. Changes in leukocyte composition had similar growth patterns in normal and diarrhea calves. As it grew, the proportion of neutrophils decreased and lymphocytes increased. However, the number of WBCs increased from 1 to 10 and 21 to 30 days in diarrhea positive calves, which is closely related to the increase in neutrophils. Therefore, those data can be used for diagnosis and treatment of diarrhea calf.

• 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.45 no.3
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• pp.201-209
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• 2022

An epidemiological study was conducted to investigate five diarrhea-causing pathogens (coronavirus, rotavirus, E. coli, Cryptosporidium, Giardia) using a rapid diagnostic kit in Hanwoo calves with diarrhea in Chungcheongbuk-do, Korea, from 2018 to 2021. A total of 22,417 fecal samples were collected from calves under 1 year of age; of those, 13,518 (60.3%) were positive for five bovine diarrhea antigens. The antigen positivity rates for rotavirus, coronavirus, E. coli, Giardia, and Cryptosporidium were 34.5%, 11.0%, 8.2%, 4.7%, and 2.0%, respectively. The prevalence of the five pathogens in calves was statistically higher in autumn and winter. The highest prevalence of the pathogens was observed in the under 1 month age group, and the incidence of diarrhea decreased with age. Rotavirus was a major pathogen in calves under 1 month of age, whereas the prevalence of E. coli increased with age. This study provides epidemiological evidence of the prevalence of calf diarrheal pathogens in Chungcheongbuk-do, Korea, which will facilitate early diagnosis and development of measures against calf diarrhea.

• 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.

• 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 Practical Agriculture & Fisheries Research
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• v.13 no.1
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• pp.103-114
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• 2011

The present survey was conducted to investigate effects of weaning age on market weights of steers and calf mortality in Hanwoo. Eight hundred and sixty-two Hanwoo cow-calf operations from all nine provinces were surveyed via personal interviews. The number of farms categorized by herd (heifer plus cow) size were 188, 364, 227 and 83 for <20 heads, 20~49 heads, 50~99 heads and >100 heads, respectively. Approximate 40% of farms surveyed weaned calves at three months of age. The percentages of farms weaning calves over three months of age were 53.5%, 37.5%, 43.7% and 39.0% for <20 heads, 20~49 heads, 50~99 heads and >100 heads, respectively. The herd size did not affect market weights of Hanwoo steers. However weaning age was negatively correlated to carcass weight of Hanwoo steers, showing that as weaning age decreased, carcass weights of Hanwoo steers increased. The average calf mortality was 5.6% and the herd size did not affect calf mortality. But weaning age was shown to be positively correlated to calf mortality and the rate of diarrhea that caused calf death, suggesting that as weaning age decreased, calf mortality and the rate of diarrhea decreased. Overall, the results of present study suggest that a decrease of calf weaning age in Hanwoo can increase the profit of Hanwoo cow-calf operations by increasing carcass weight of Hanwoo steers and by decreasing calf mortality.

• 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.