一貫化養豬場豬黴漿菌感染狀況及治療策略之研究

Infection status and treatment strategies of Mycoplasma suis in a farrow-to-finish pig herd

蔡承諭(Tsai chen-yu)

指導教授 ： 邱明堂 ； 林昭男

國立屏東科技大學/獸醫學院/獸醫學系所/碩士(2022年)

https://doi.org/10.6346/NPUST202200269

摘要

豬黴漿菌 (Mycoplasma suis；M. suis)是目前世界上已知粒徑最小且具有自我複製能力的生物體，缺乏細胞壁並能廣泛感染各年齡層豬隻，造成養豬產業嚴重經濟損失。母豬族群於豬場具有較高之M. suis檢測陽性率，且目前台灣針對M. suis之防治策略較為混雜，相關之驗證資料也較少，因此本研究主要將針對母豬比較不同的預防及治療措施，並調查母豬及各年齡豬隻的感染情況，以了解M. suis最佳現場防治方法。於台灣南部之一家M.suis陽性養豬場進行實驗，試驗1將M. suis檢測陽性豬隻分為5組，每組各8隻母豬，第一組以飼料投予 tiamulin (TIA) 30 ppm、第二組以飼料投予 tylosin (TYS) 220 ppm、第三組飲水投予doxycycline (DOX) 50 ppm、第四組肌肉注射 oxytetracycline (OTC) 20 mg/kg 及第五組無投予藥物治療之對照組，飲水及飼料給藥組連續給藥7日，肌肉注射組則連續給藥3日，各組豬隻於試驗開始後 (day post experiment；DPE)第8天 (DPE 8)採血，停藥7天後，再重複一次相同之治療週期，並於DPE 22採血，此部分試驗進行二重複。所有樣品均以之即時定量聚合酶連鎖反應 (real-time quantitative polymerase chain reaction；qPCR)檢測M. suis，評估不同藥物之藥效。DPE8及DPE 22檢測結果顯示，第一組陽性率分別為100%及87.5%，第二組陽性率分別為75%及87.5%，第三組陽性率為87.5%及62.5%，第四組陽性率均維持0%，以及第五組陽性率仍維持100%。第四組之DPE 8及DPE 22的陽性率顯著低DPE 0 (P<0.001)，二重複間數據相似。試驗2追蹤10頭母豬及其所生產之3頭小豬，定期採集血清樣本，利用qPCR檢測M. suis，母豬連續追蹤一年，仔豬則追蹤至上市年齡，結果顯示母豬五至八月之M. suis陽性率顯著地高於二、十一及十二月的血清陽性率；而仔豬於1及4週齡的陽性率顯著地低於12、16及20週齡的M. suis陽性率，綜上所述，以肌肉注射OTC 20 mg/kg連續給藥3天，可有效降低母豬M. suis陽性率，另外母豬族群於夏季有較高的陽性率，且豬群各年齡層之陽性率有隨著年齡提高而增加的趨勢。

關鍵字

豬黴漿菌 ； 母豬 ； 防治策略

並列摘要

Mycoplasma suis (M. suis) is the smallest organism known to be self-replicating in the world, lacks cell walls and widely infects swine. The efficacy of treatment strategies against M. suis were unclear in Taiwan. Therefore, the aim of this study is to evaluate efficacy of different strategies to prevent and control M. suis. This study was conducted on a pig farm in southern Taiwan. 40 M. suis positive sows were selected and equally divided into 5 groups and each group was administrated with different antimicrobial treatments. Group 1, tiamulin (TIA) 30 ppm as feed additives for 7 days. Group 2, tylosin (TYS) 100 ppm as feed additives for 7 days. Group 3, doxycycline (DOX) 50 ppm in drinking water for 7 days. Group 4, oxytetracycline (OTC) 20 mg/kg by intramuscular injection for 3 days and Group 5, without any treatment. Serum samples were collected for M. suis detection by real-time quantitative polymerase chain reaction (qPCR) at 0, 8 and 22 day post experiment (DPE). At DPE 8 and DPE 22 the M. suis serum positive rate of group 1 showed 100% and 87.5%, positive rate of group 2 were 75% and 87.5%, positive rate of group 3 were 87.5% and 62.5% to 62.5%, positive rate of group 4 were remained 0% and positive rate of control group 5 remained 100%. Collectively, the intramuscular injection OTC 20% 20 mg/kg for 3 consecutive days could effectively reduce serum positive rate of M. suis in sows. Experiment 2 tracked 10 sows and 3 piglets and collected serum samples every month for M. suis qPCR, The results showed that the positive rate of M. suis in sows from May to August was significantly higher than February and November and December, and the positive rate of M.suis at 1and 4 week were significantly lower than 12, 16 and 20 week, prevalence of M. suis may increased by age. Collectively, intramuscular injection of OTC 20 mg/kg for 3 consecutive days can effectively reduce the positive rate of M. suis in sows, Sows have higher serum positive rate of M. suis during summer and prevalence of M. suis may increased by age.

並列關鍵字

M. suis ； Sows ； real-time quantitative polymerase chain reaction

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