蘭嶼豬豬瘟疫苗免疫成效與疾病調查

實驗動物被廣泛運用在醫學研究及藥物研發上，其中小型豬因解剖生理特性與人類有諸多相似之處，已成為生醫研究實驗動物種類之一。臺灣政府投入大量資源於本土小型豬種之育種研究，並陸續育成李宋豬與蘭嶼豬等小型豬品種。現今蘭嶼豬族群的相關研究多著重於分子遺傳、種原保存及營養等領域，然而針對此原生小型豬種間免疫與疾病概況之研究則較匱乏，因此本研究旨在評估蘭嶼豬族群經豬瘟疫苗注射後血清學之動態趨勢，探討免疫計畫的合適性及調查蘭嶼豬各年齡層疾病概況。本研究為國內首次系統性針對蘭嶼豬進行之免疫適期及疾病調查。研究分為三個試驗，試驗一以逢機方式挑選 24 頭待產蘭嶼母豬，分娩後 3 週採集血樣，每胎逢機挑選 3 頭仔豬，仔豬則不免疫豬瘟疫苗，並於 3、6、9、12 及 15 週齡採集血液樣本，探討蘭嶼豬豬瘟移行抗體之消長模式以評估合適之免疫時機；試驗二則逢機挑選 36 頭於 9 及 12 週齡免疫豬瘟疫苗之豬隻，分別於 9、12、15、18、24、36 及 48 週齡採集血液樣本，探討豬瘟疫苗免疫成效及免疫反應持續時間；試驗三為收集病死之蘭嶼豬病例分析好發疾病之類型。結果顯示，試驗一之蘭嶼豬於 3、6、9、12 及 15 週齡時ELISA抗體力價 (Blocking percentage)平均值分別為 65.0 ± 25.4 %、48.2 ± 25.8 %、34.6 ± 24.1 %、25.6 ± 22.0 %及 10.3 ± 13.7 %，而抗體陽性率分別為 81 %、62 %、35 %、19 %及 6 %；試驗二之 ELISA 抗體力價於 9、12、15 及 18 週齡分別為 35.3 ± 25.0 %、75.2 ± 5.2 %、81.7 ± 4.3 %及 85.9 ± 4.1 %，在 9-18 週齡抗體力價穩定且持續揚升，於24、36 及 48 週齡時抗體力價分別為 89.8 ± 4.5 %、86.7 ± 4.0 %及 79.7 ± 7.1 %，在 24-48 週齡抗體力價則出現逐漸下降的情形，但仍維持在72 %的效價以上。試驗三分析 49 頭病例經病理學診斷分類統計以呼吸系統疾病佔 78 %、消化系統疾病佔 31 %與心血管系統疾病佔 20 %，其中哺乳豬與保育豬以呼吸系統及消化系統病變為主，生長肥育豬以呼吸系統及心血管系統病變為主，而種豬則以呼吸系統及泌尿系統病變為主。綜上所述，在蘭嶼母豬每空胎免疫一劑豬瘟疫苗結合蘭嶼豬仔豬之豬瘟移行抗體力價與抗體陽性率之檢測結果，9 週齡區間應為合適之免疫時機，而豬隻經疫苗免疫後抗體反應良好且直至 48週齡時仍具良好保護效力，同時經統計該場各年齡層好發疾病，則發現以呼吸道疾病為大宗。

關鍵字

蘭嶼豬；疾病監測；血清學；免疫適期

並列摘要

Laboratory animals have played an important role in medical research and drug discovery. Since the anatomic, and physical characters were similar to human, miniature pigs gradually became more and more important in biomedical research. Taiwan Government also put in large amount of efforts on the breeding and research of indigenous miniature pig breeds. Meanwhile, the breeding of Lee-Sung pig and Lanyu pig for biomedical research were also accomplished. Nowadays, the studies of the Lanyu pig are focused on molecular genetics, conservation and nutrition. However, the researches of immune status and disease survey are rare. Therefore, the objectives of this study is to understand the dynamic trend of the classical swine fever (CSF) serology on Lanyu pigs with vaccination, evaluate the current vaccination programs, investigate the diseases status of various age groups. This study is the first systematic investigation on the appropriate vaccination program and analysis of common disease for Lanyu pig in Taiwan. This study was divided into three trials. In trial one, twenty-four pregnant sows and three offsprings from each parity were randomly selected to the test. Sows were collected blood samples at three weeks after farrowing. Piglets without CSF vaccination were collectedblood samples at the age of 3, 6, 9, 12 and 15 weeks. The aim of this trial was to evaluate the dynamics of CSFV maternal-derived antibodies. In trial two, thirty-six piglets with CSF vaccination were randomly selected and collected blood samples at the age of 9, 12, 15, 18, 24, 36 and 48 weeks. The aim of this trial was to assess the efficacy of vaccination program and duration of immune response to CSF vaccine. In trial three, dead pigs were necropsied to investigate the diseases status of various age groups. The results showed that the CSFV specific antibody (blocking percentage) at the age of 3, 6, 9, 12 and 15 were 65.0 ± 25.4 % , 48.2 ± 25.8 %, 34.6 ±24.1 %, 25.6 ± 22.0 % and 10.3 ± 13.7 %, respectively. The positive percentage of specific antibody were 81 %, 62 %, 35 %, 19 % and 6 %, respectively. In trial two, the blocking percentage at the age of 9, 12, 15 and 18 weeks were 35.3 ± 25.0 %, 75.2 ± 5.2 %, 81.7 ± 4.3 %, 85.9 ± 4.1 %, respectively. It indicated that the CSFV specific antibody was constant rise from 9 to 18 weeks. The blocking percentage at the age of 24, 36 and 48 weeks were 89.8 ± 4.5 %, 86.7 ± 4.0 % and 79.7 ± 7.1 %, respectively. It revealed that the CSFV specific antibody gradually reduced but still maintained over 72 %. In trial three, the pathological diagnosis showed that the percentage of respiratory, digestive and cardiovascular disease were 78 %, 31 % and 20 %, respectively. The major disease of suckling and nursery pigs were respiratory and digestive infection. The major disease of growing-finishing pigs were respiratory and cardiovascular disease. The major disease of breeding stock were respiratory and urinary disease. In conclusion, it indicated that the vaccination should be implemented around 9 weeks of age by evaluating the maternal-derived antibodies and positive percentage of specific antibody on piglets and conditions of sows inoculating with CSF vaccine after weaning. Meanwhile, the CSF vaccine was still effective on preventing disease at the age of 48 weeks and the most common disease at various age groups was respiratory infection on the farm.