• 한국동물위생학회지
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• 제36권3호
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• pp.181-186
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• 2013

This study was conducted to isolate the Actinobacillus pleuropneumoniae (APP) and to find out the distribution of 15 serovars mainly in southern Gyeonggi province, Korea. From July 2011 to Nov. 2012, a total of 2,204 slaughter pigs (110 herds) were inspected for evaluation of APP like pneumonic lesions. 48 (33.8%) APP strains were isolated from the 142 lungs and identified using PCR assays (cps, apx/omlA, biovar). Consequently, the serotype ratio were as in the following; type2 41.7% (n=20), type5 33.3% (n=16), type12 10.4% (n=5), type1 6.2% (n=3), type4 and 7 2.1% (n=1) and unknown 4.2% (n=2). Also serological test was implemented for 452 (83 herds) serum samples randomly collected from above slaughter pigs using commercial ELISA kits. The positive ratio of each serotype for tested pigs were 19.1% (77/404) on [2], 7.1% (32/452) on [3, 6, 8], 6.9% (28/404) on [5a, 5b], 6.2% (28/452) on [4, 7], 2.8% (9/320) on [12], 2.0% (9/452) on [1, 9, 11] and 0.0% (0/452) on [10]. And 49.3% (223/452) of pigs were positive on apxIV antibody. On the basis of latter screening test, the infected farm ratio accounted for 71.1% (59/83) and that was much higher than previously reported data.

• 대한수의학회지
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• 제39권4호
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• pp.730-737
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• 1999

A national animal health monitoring system(NAHMS) in Gyeongnam area was started from 1997 to develop statistically valid data for use in estimating disease frequencies in dairy cattle, and the associated costs. The objectives of this study were to : (1) discribe what was done to implement and maintain the system in Gyeongnam ; (2) present selected disease frequencies ; (3) discuss the epidemiological consideration of what was done and implications for the results obtained. Veterinary Medical Officers(VMOs-professors and graduate students from Gyeongsang National University, Faculty of Gyeongnam Livestock Promotion Institute, and Clinic veterinarians) served as data collectors. After training on current disease and management problems of dairy cattle, interview techniques, sampling methods, and data collection instruments, the VMOs participated in selection of the sample herds and data gathering. Forty of 167 dairy herds were selected randomly and the VMOs visited farms once a month for 12 months to collect data about management, disease, inventory, production, preventive treatment, financial and any other relevant data. Strict data quality control devices were used. Specific feed-back was developed for the producers and data collectors. Of the three age groups studied, cows had the greatest number of disease problems. The six disorders found most frequently were (from the highest to the lowest) breeding problems, clinical mastitis, birth problems, gastrointestinal problems. metabolic problems, and lameness. In young stock, respiratory, multiple system, breeding problems, and gastrointestinal problems were pre dominant, whereas in calves, gastrointestinal, respiratory, and integumental problems were major.

• 대한수의학회지
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• 제47권4호
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• pp.417-423
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• 2007

Serological surveillance programs in animal populations are becoming increasingly important to estimate prevalence of a specific disease and subsequently to document disease-free status in a region or a country. For these purposes, the programs need to be based on both theoretical and economical aspects from the designing phase. From Aujeszky's disease (AD)-eradication program point of view, group of animals (aggregates, herds) not individual animal is the more important sampling unit of concern. In this study the authors therefore attempted to compute an appropriate sample size tailored to a current surveillance program against AD, assuming that the goal of this program is either herd-level prevalence estimation or documentation of AD-freedom. For prevalence estimation, assuming a finite population with imperfect sensitivity (Se) and specificity (Sp) of ELISA kit for AD diagnosis, the number of herds present, expected herd prevalence, and desired accuracy for a certain level of confidence, sample size was estimated at herd-level in the first stage and individual animal-level in the second stage. A two-stage sampling design was used to calculate a sample size to indicate AD-freedom. In this instance, the computation was based on the possible detection of a predetermined prevalence at a certain herd-level Se and Sp. This study indicated that the sample size varied with predetermined confidence, tolerance, Se and Sp at herd- and animal-level, and within- and among-herd prevalence. In general, smaller sample size was required to estimate AD prevalence than to document of AD-freedom. Compared to individual-based samples, two-stage sampling strategy requires a larger sample size to show disease-freedom. Statistical considerations including herd-level test characteristics when designing surveillance program also are further discussed.

• 한국동물위생학회지
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• 제24권1호
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• pp.9-14
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• 2001

This study was carried out to investigate the prevalence of Neospora caninum infection in dairy cow and Korean native cattle(KNC), raised in several Chungnam province. To determine the prevalence of antibodies to N caninum, a total of five hundred fifty six sera were analyzed by indirected fluorescent antibody(IFA) test. Five hundred thirty three sera were collected from fifteen dairy herds and twenty three sera were taken from fourteen KNC herds from December 1999 to November 2000. Seropositive ratio of the dairy cattle sera were individually or herdly tested and showed 64.2% and 93.3%, respectively. It was recorded with 78.6% and 47.8% in KNC. The seropositive ratio of dairy cattle was depended on the size of ranch. It was 92.2, 60.7 and 57.9% at the size of less than thirty, thirty to seventy and more than seventy one cattle, respectively However, it was different from the province of Chungnam. The seropositive ratio to N caninum of dairy cattle were 79.5, 53.1, 61.4 and 31.1% at Gongju, Yeongi, Geumsan and Cheongwon, respectively. It showed difference at the growth stage and sex of cattle. The seropositive ratios of N caninum of calf, heifer, premiparous, multiparous(2nd-5th), multiparous (6>th) and bulls confirmed to 25.0, 50.3, 70.3, 71.2, 50.0 and 50.0%, respectively. It was related with brucellosis in cattle. The infected ones with brucellosis were 75.7% of seropositive ratios to N caninum. The results of this study indicated that N caninum infection was widespread in Chungnam province and confirmed existing with brucellosis in cattle.

• 한국동물위생학회지
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• 제24권1호
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• pp.83-88
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• 2001

It is impotent to identify the causative agents of abortion in equine for minimizing the loss of breeding costs in equine Industry. Recently, the abortion has often occurred in equine herds and thus the purpose of the study was aimed at the identification of equine herpesvirus-1, one of the frequent pathogens to abortion, using polymerase chain reaction. Six fetuses to be aborted at nine to ten months in pregnancy reared in six herds were used in the study. Two primers in the PCR were made from glycoprotein B gene of EHV-1. The primers specific for EHV-1 amplified 1880 bp of PCR products from DNA extracts from thorax fluids, livers, lungs, and spleens of four in six aborted fetuses. Consequently, PCR could be applied to diagnose the abortion of EHV-1 and also confirmed to play a major role of the viral pathogen associated with equine abortion in Jeju island.

• Asian-Australasian Journal of Animal Sciences
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• 제33권8호
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• pp.1360-1368
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• 2020

Objective: The aim of our study was to determine the associations of heifer reproductive performance with survival up to the first calving, first-lactation milk yield, and the probability of being culled within 50 days after first calving. Methods: Data from 33 large Holstein-Friesian commercial dairy herds were gathered from the official milk recording database in Hungary. The data of heifers first inseminated between January 1, 2011 and December 31, 2014 were analyzed retrospectively, using Cox proportional hazards models, competing risks models, multivariate linear and logistic mixed-effects models. Results: Heifers (n = 35,128) with younger age at conception were more likely to remain in the herd until calving, and each additional month in age at conception increased culling risk by 5.1%. Season of birth was related to first-lactation milk yield (MY1; n = 19,931), with cows born in autumn having the highest milk production (p<0.001). The highest MY1 was achieved by heifers that first calved between 22.00 and 25.99 months of age. Heifers that calved in autumn had the highest MY1, whereas calving in summer was related to the lowest milk production (p<0.001). The risk of culling within 50 days in milk in first lactation (n = 21,225) increased along with first calving age, e.g. heifers that first calved after 30 months of age were 5.52-times more likely to be culled compared to heifers that calved before 22 months of age (p<0.001). Calving difficulty was related to higher culling risk in early lactation (p<0.001). Heifers that required caesarean section were 24.01-times more likely to leave the herd within 50 days after first calving compared to heifers that needed no assistance (p<0.001). Conclusion: Reproductive performance of replacement heifers is closely linked to longevity and milk production in dairy herds.

• 한국동물위생학회지
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• 제19권2호
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• pp.126-138
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• 1996

Lungs from 109 slaughter pigs with gross lesions indicating enzootic Pneumonia of pigs(EPP) and 16 grossly normal lungs, all originating from seven different herds, were subjected to microbiological examinations. The microbiological studies were included both bacterial and mycoplasmal culture. From lungs of 125 slaughter pigs, 87.2% pigs were pneumonia lesions alone or complexly Mycoplasma spp., pasteurella multocidu(p. multocida), Streptococcus spp., and Actinobacillus pleuropneumoniue(A. pleuropneumoniae) were detected in 39.4%, 42.2%, 13.8%, and 3.7% of the pneumonic lungs, respectively. P. multocida was the most frequently isolated organism in pneumonic lungs. Mycoplasmas not isolated organism in 33.9% the pneumonic lungs even If [here are gross lessions mycoplasmas. The amounts of pneumonia in lungs with Mycoplasma spp. alone, a concurrence of Mycoplasma spp. and P. multocida, p. multocida alone, a concurrence of P. multocida and A. pleuropneumoniae, and a concurrence of Mycoplasma spp. and A pleurdpneumoniae were 10.1%, 22.7%, 18.7%, 25%, and 30%, respectively These findings indicated that p. multocida might be involved in the pathogenesis of pneumonia in slaughter pigs. Mycoplasma spp. was also, in this study, associated with higher frequency of pneumonia. The frequency of pigs snout lesion grade 0∼5 inclusive were 27.2%, 28%, 19.2%, 16%, 6.4%, and 3.2% from 125 slaughter pigs. 32(25.6%) pigs were positive and 13~30% in the pigs from seven herds were found to be infected with atrophic rhintis (AR). A total of 46 P. multocida strains In pneumonic lungs were further characterized by capsular serotyping and testing for production of dermonecrotic toxin. 42(91.3%) of strains were capsular A and 4(8.7%) were type D. Out of the type A and type D strains, 86% and 75% were toxigenic, respectively.

• 대한수의학회지
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• 제45권1호
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• pp.55-61
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• 2005

Serum samples of 1,175 pigs from 148 Korean swine farms not using Mycoplasma hyopneumoniae (M. hyo) vaccines were collected for seroepidemiological study of M. hyo infection by indirect ELISA method. Informations of each farm were provided about province where the farm was located and season when blood samples were collected. Then, the selected farms were divided into farm units which had 5 serum samples according to production stages : sow, suckling piglet (<30 days old), nursery pig (30-70 days old), and growing pig (>70 days old). Seroprevalence of M. hyo infection according to production stages, province, and season was investigated by using ELISA-positve rate of the selected samples for each study. This study showed that 85.34% (78.94-91.78%, 95% CI) of farms were positive to M. hyo infection and 34.81% (32.09-37.53%, 95% CI) among pigs were sero-positive to M. hyo infection in Korean swine farms. In the study of seroprevalence by production stage, most farms had sows and growing pigs which were sero-positive to M. hyo infection (sow: 83.05%, growing pigs: 87.72%) and most pigs seemed to be naturally infected by M. hyo at 8-10 weeks of age. Also, M. hyo infection showed seasonal pattern that most pigs were infected in late fall to early winter. However, in the study of seroprevalence by province, there was no significant correlation between province and M. hyo sero-positive rate.

• 한국동물위생학회지
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• 제32권1호
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• pp.27-32
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• 2009

We studied the seroprevalence of four respiratory pathogens in Korean swine farms located in Chungnam, Chungbuk, Gyeongnam and Gyeongbuk provinces during the period of spring of 2007 to winter of 2008. Serological tests were performed using commercial ELISA kits. A total of 530 serum samples were tested for the antibodies against porcine reproductive and respiratory syndrome virus (PRRSV), porcine circovirus type 2 (PCV2), Mycoplasma hyopneumoniae (M. hyo) and Actinobacillus pleuropneumoniae (APP). Seroprevalence for four respiratory pathogens were estimated by ELISA-positive rates of the submitted samples. The overall seropositive rates of PRRSV, APP, M. hyo and PCV2 were 32.6%, 10.6%, 38.4% and 88.5%, respectively. By production stage, the seropositive rate for PRRSV was highest in nursery pig populations (46.2%). In contrast, the highest seropositive rates of APP and M. hyo were observed in sow and growing pigs. However, the seroprevalence of PCV2 was ranged from 85.7% to 89.6%, showing no significant difference among the production stages. In the seroprevalence by season, PRRSV, APP and M. hyo infections revealed typical seasonal patterns that the peaks of the seropositive rates were observed between early winter and late spring. In case of PCV2, no particular seasonal patterns were noticed. The pig herds in Gyeongbuk province where PMWS was endemic during the period of survey showed the highest seropositive rates for PRRSV (44.6%), M. hyo (47.5%), and PCV2 (92.7%). Seropositive rates for APP of four provinces were approximately 10%. These results might be valuable for control and prevention of the respiratory diseases and helpful to define strategies related to vaccine applications.

• 한국동물위생학회지
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• 제39권4호
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• pp.231-237
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• 2016

The present study was conducted to investigate the lesion of red internal organs in slaughtered pigs and provided assistant data for pig farms. During March to December 2015, a total of 1,160 lung samples out of 58 herds were collected randomly from pigs slaughtered in Jeonbuk province. In addition, 290 hilar lymph nodes from pig with pneumonic lung lesion (5 samples per herd) were screened for selected viral and bacterial pathogens. Gross lesions of lungs such as swine enzootic pneumonia (SEP), pleuritis, pleuropneumonia, pericarditis and liver white spots were examined. The overall prevalence of SEP was 64.3% (746/1,160). In the analysis of seasonal prevalence, there was an increase of occurrence during the spring months (287/400, 71.8%) and decrease during the fall months (93/200, 46.5%) among the whole herds. The mean number of SEP score per pig was $1.20{\pm}1.28$. The prevalence of pleuropneumonia, pleuritis, pericarditis, and milk spot was 25.5% (296/1,160), 44.1% (512/1,160), 3.8% (44/1,160) and 17.6% (204/1,160), respectively. The most frequent region with lung lesion was diaphragmatic lobes (left 17.1%, right 17.3%). In the detection of viral pathogens by PCR, porcine circovirus type2 (PCV2) was positive in 86.9% (252/290), while porcine reproductive and respiratory syndrome virus (PRRSV) was not detected, In the case of bacterial pathogens, 50 microorganisms were isolated by PCR and/or microbiological test. The most frequently isolated bacteria was Streptococcus suis (20, 34.4%), followed by Pasteurella multocida (17, 29.3%), Streptococcus spp. (11, 3.4%), Actinobacillus pleuropneumoniae (2, 8.9%).