동절기 도축돈 폐병변 발생 양상에 관한 역학조사

Epidemiological study on prevalence of Iung lesions of slaughtered pigs in winter

This study was carried out to investigate and analyze the gross lesions of lungs in slaughtered pigs. Pigs were collected from the areas of Kyounggj, Chungbuk, Chungnam and Kangwon provinces from November to December 1999. One hundred-eleven pigs(17.4%) had lung lesions with various degrees among 639 pigs tested. By the standard scoring system, mean score of the lung lesion was 25.6+13.2. Regional prevalence of lung lesions were 23.5%(8/34)) in Kangwon, 17.3%(61/352) in Kyunggi, 15.7%(32/204) in Chungnam and 20.4%(10/49) in Chungbuk. Mean number of pulmonary lesions per pig were 2.87. Most frequent region with pulmonary lesions was right cranial lobe(30.1%) and the decreasing prevalence rates were followed by 23.8% in right middle lobe, 21.05 in right accessory lobe, 15.0% in left cranial lobe, and 5.0% in left middle and accessory lobe(5.0%) and also there was the same prevalent tendency on pulmonary lesions in each lobes of 111 pigs with gross lesion. Isolation rate of bacteria from the affected lungs was 72.1% and main pathogen was Pasteurella multocida. Gross and histological examination of pulmonary lesions in some pigs suggested that there were no marked changes regarded as the correlation with specific diseases except fibropurulent bronchopneumonia which was suspective of some respiratory bacteria including Pasteurella multocida and peribronchiolar lymphoid hyperplasia in varying degrees which was strongly associated with mycoplasmal infection. Consequently, the results in the study were suggested that there was consistently exposed against many causative factors including bacteria in the considerable number of pig herds rearing in the middle area in Korea.