• Korean Journal of Veterinary Research
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• v.55 no.2
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• pp.75-80
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• 2015

Calf losses have an economic impact on larger Korean native cattle (KNC) breeding farms due to replacement, productivity, and marketing. However, little research on KNC calf mortality or causes of calf death on large-scale breeding farms has been conducted. Based on medical records and autopsy findings from the Hanwoo experimental station of the National Institute of Animal Science, calf death records from 2002 to 2011 were used to identify the causes of mortality. Mortality rate of KNC calves was 5.7%. Large differences (1.8~12.6%) in yearspecific mortalities were observed. Calf deaths were due to digestive diseases (68.7%), respiratory diseases (20.9%), accidents (6.0%), and other known diseases (2.2%). The main cause of calf death was enteritis followed by pneumonia, rumen indigestion, and intestinal obstruction. The greatest number of calf deaths occurred during the fall followed by summer. These results indicated that enteritis and pneumonia were the main reasons for calf death. However, autopsy findings demonstrated that other factors also caused calf death. This study suggested that seasonal breeding and routine vaccinations are the most important factors for preventing calf death, and improving calf health in high land areas with low temperature.

• Journal of agriculture & life science
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• v.50 no.2
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• pp.117-124
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• 2016

This study was estimated the effect of environmental factors and each of them on auction price of Hanwoo calves. The auction prices of Hanwoo calves(19,592head) registered pedigree were sampled in Gyeongsangnam-do from 2014 to 2015. The environmental factors were highly(p<0.01) affect to the auction price of Hanwoo calves. With the analysis of contribute factor used the semi-partial correlation, the value of regression equation(Adj R-Square) was 0.701. The semi-partial correlation values of sex, auction body weight, auction age, auction year, auction season, and auction area were 0.11563, 0.20013, 0.02823, 0.10727, 0.00330 and 0.02963, respectively. And the highest contribution factor was body weight, and then, followed sex, auction year, auction area and auction age. In conclusion, it could be suggested that Hanwoo calf farmer should improve calf body weight to increase auction price by not only breeding, but also optimal management. Additionally, it is expecting in the future that competitiveness and income of farmers will be affected deeply by the holding and producing of predominant genes which is coincidence with breeding principles. However, further study should be conducted for the better understand caused by the limit of previous studies which was estimated the correlations of auction price and each factors.

• Journal of Animal Science and Technology
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• v.49 no.2
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• pp.239-244
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• 2007

This study was conducted to investigate effects of weaning age on growth perforance, feed intake, disease occurrence and maternal reproductive efficiency in Hanwoo. Sixty experimental calves were allocated into two groups, early weaned (n=29, calf age 90 d, EW) and normally weaned (n=31, calf age 120 d, NW). Body weights and average daily gains during nursing and post-weaning periods were similar between two groups (p>0.05). Weaning age had no effect on calf starter, grass hay, dry matter, crude protein and TDN intakes of calves (p>0.05). Maternal calving interval in EW was shortened by 23 days compared to NW (p>0.05). Any difference in occurrence of disease was not observed between groups. Present results indicate that early weaning age has no negative effects on growth performance, feed intake or on disease occurrence in Hanwoo calves. And it has positive influence on maternal calving interval.

• Journal of Animal Science and Technology
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• v.54 no.2
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• pp.141-147
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• 2012

The present survey was conducted to provide basic information on Hanwoo calf management. Eight hundred and sixty-two Hanwoo breeding farms from all nine provinces were surveyed via personal interviews. The percentages of farms categorized by herd size were 30.5%, 32.8%, 26.0% and 10.7% for <50 heads, 51-100 heads, 101-200 heads, and >200 heads, respectively. More than 50% of farms offered calf starter at 6-10 days of age, showing that calf starter was offered relatively at an earlier age. Calf starter was replaced every three days by 30.1% of farms. The percentages of farms replacing starter weekly (19.2%) were even higher than those of replacing starter daily (18.8%), suggesting that the frequency of replacing starter needs to be increased to maintain starter freshness and to increase starter intake. About one-third of farms offered forage at 6-10 days of age and 21% of farms offered even at 1-5 days of age although it has been well known that forage does not contain either nutrient density or nutrient profile necessary to stimulate rumen papillae development, especially before weaning. Furthermore, about half of farms used rice straw with calf starter. Water was offered relatively at an earlier age (1-5 days of age) by 55% of farms. Deciding when to wean calves should be based on starter intake rather than age but less than 50% of farms decided weaning age by starter intake. In conclusions, to reduce weaning age of Hanwoo calves by rapid rumen papillae development it is necessary to provide fresh starter and water by increasing frequency of starter replacing and water trough cleaning and not to feed forage before weaning.

• Journal of Practical Agriculture & Fisheries Research
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• v.24 no.2
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• pp.12-22
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• 2022

The purpose of this study is to design a farming model for Hanwoo start-up farmers. I prepared a Hanwoo production plan model according to the growth cycle of Hanwoo using EXCEL. The Hanwoo production plan model was simulated in two model: Model 1 (a model that only purchases Hanwoo calf) and Model 2 (a model that purchases both Hanwoo cow and Hanwoo calf). Next, I reviewed the profits and costs of two Hanwoo simulation models. As a result of the analysis, Model 2 has the following characteristics compared to Model 1. First, Model 2 requires a lot of initial investment. Second, Model 2 is advantageous in terms of farm cash balance because imports occur every year. Third, Model 2 can efficiently use facilities and machines.

• Journal of Animal Reproduction and Biotechnology
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• v.39 no.3
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• pp.201-211
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• 2024

Background: Hanwoo cattle farmers aim to improve calf production and reproductive efficiency. Recovery of the reproductive tract postpartum is a critical factor influencing the postpartum period and conception of breeding cows. This study aimed to precisely analyze the recovery process of the reproductive tract in primiparous Hanwoo postpartum and to establish recovery criteria. Methods: Ten primiparous Hanwoo cows were used in this study. After parturition, estrus was examined daily using visual observations and estrus detection patches. Ovarian recovery, cervical diameter, and uterine horn diameter were examined using ultrasonography four times per week. Results: The analysis revealed that the first estrus occurred at 19.1 ± 6.5 days postpartum, the first ovulation at 27.1 ± 4.5 days, and the first normal estrus cycle at 39.2 ± 6.4 days. The ovulation rate during the first estrus was 40%. A normal estrus cycle occurred in 11.1% of patients at the first ovulation. The cervix diameter recovered to 42.0 ± 3.5 mm and the uterine horn diameter to 34.4 ± 7.1 mm by 24 days postpartum, with the difference in uterine horn diameter recovering to 2.6 ± 1.2 mm by 31 days postpartum. Conclusions: This study can aid in determining the optimal breeding time for postpartum primiparous Hanwoo cow and provide foundational data for Hanwoo breeding studies.

• Journal of Veterinary Clinics
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• v.22 no.4
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• pp.408-411
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• 2005

Schistosomus reflexus is the most common monstrosity found in cases of bovine dystocia and it occurs mostly in cattle. Caesarian section performed and retracted abnormal foetus from dystocia in Holstein cow. It was the first observed schistosomus reflexus Holstein calf in Korea. The body and chest walls were bent laterally and dorsally leaving the thoracic and abdominal viscera exposed. Clefts of the sternum from part of the defect in which there is, simultaneously, lordosis, dorsal reflection of the ribs and complete eventration of viscera, severe ventral curvature of the spinal column, non-union of the pelvic symphysis and dorsal reflection of the pelvic bones with the occiput of the head lying near the sacrum. The limbs are usually ankylosed. The liver was abnormal in shape and cystic in nature. The lung was smaller and thymus were bigger than those of the normal calf, The ruminant stomach was normal, however, abomasum distended with amnionic fluid. The other organ including heart, spleen and internal organ have normal shape.

• 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 Animal Science and Technology
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• v.53 no.5
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• pp.497-502
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• 2011

The present survey was conducted to provide basic information on Hanwoo calf weaning age and farmer's understanding of early weaning. Eight hundred and sixty-two Hanwoo breeding farms from all nine provinces were surveyed via personal interviews. The percentages of farms categorized by herd size were 30.5%, 32.8%, 26.0% and 10.7% for <50 heads, 51~100 heads, 101~200 heads and >200 heads, respectively. The percentage of farms weaning calves at three months of age were 39.2% and 12% of farms weaned calves less than two months of age. But the percentage of farms weaning at or over four months of age were still high, being 16.1% at four months of age and 16.6% over five months of age, respectively. The result of the present study showed that calf weaning age in Hanwoo was inconsistent and higher percentage of farms wean calves at three months of age among the surveyed farms. The improvement of cow reproductive performance was answered as the biggest merit of early weaning.

• Korean Journal of Veterinary Service
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• v.46 no.4
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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.