第二型豬環狀病毒在豬隻之排毒模式及防治策略之研究

Excretion Pattern and Prevention Strategies of Porcine Circovirus Type 2 in Pigs

葉麗君(Li-Jun Ye)

指導教授 ： 邱明堂

國立屏東科技大學/農學院/獸醫學系所/碩士(2010年)

https://doi.org/10.6346/NPUST.2010.00058

摘要

第二型豬環狀病毒（porcine circovirus type 2；PCV2）為造成豬隻常見呼吸道疾病的病原之一。目前已知PCV2可由空氣、接觸、糞尿、乳汁及精液等途徑感染豬隻，然而有關豬隻自然排毒途徑及其排毒期為何，仍尚未完全明瞭。本研究以田間PCV2汙染場豬隻及Caesarean-derived, colostrum-deprived（CDCD）豬進行試驗，以究明PCV2在豬群中之排毒模式。此外，亦檢測在不同飼養模式下，豬群之排毒狀況，以尋求PCV2最佳的防治策略。所有試驗豬隻於4-15週齡間，每週分別採取血液、唾液、鼻黏液及糞便拭子等樣品，以多引子聚合酶鏈鎖反應（multiplex polymerase chain reaction；mPCR）進行PCV2檢測，血清樣品則另進行PCV2特異性抗體檢測。於田間試驗的結果顯示，PCV2可由鼻黏液、唾液、糞便、血液等途徑排毒，以糞便拭子及唾液檢出率最高，排毒期均為5-6週。PCV2抗體於4-6週齡可測得，並逐漸下降，在11-13週齡逐漸上降。CDCD豬於接種PCV2後1週，即可從各樣本中測出PCV2核酸，排毒時間可持續4-6週，排毒後1-2週，可於血清中偵測出PCV2特異性抗體，並於排毒後6-9週達到高峰。同居感染組於同居後1-3週，可由各樣本中測得PCV2，排毒期可持續3-4週；而其抗體在同居感染後8週達到高峰。分地式飼養模式之試驗結果發現，此一模式可有效降低豬
隻PCV2感染率，排毒期及死亡率。總和上列各項實驗可知，PCV2感染豬隻後，豬隻排毒時間至少可達6週，而以分地式飼養模式及統進統出之飼養管理方式，似可有效阻斷豬群間PCV2的傳染。

關鍵字

第二型豬環狀病毒 ； 排毒模式 ； 防治策略 ； 排毒期

並列摘要

Porcine circovirus type 2（PCV2）is a common infectious pathogen in pigs worldwide. Nowadays, many transmission routes of PCV2 between pigs had been proved. However, the excretion pattern and duration remain unclear. Two studies were conducted to investigation the PCV2 shedding routes and duration in herd-raised and Caesarean-derived, colostrum-deprived（CDCD）pigs. In addition, PCV2 shedding pattern also compared in different housing model. Nasal, oral, and fecal swabs as well as blood samples were collected weekly throughout the age of 4-15 weeks in all groups of trial pigs. PCV2 DNA was detection from all the samples by using multiplex polymerase chain reaction（mPCR）. IFA was applied for determination the PCV2-specific antibodies in serum. PCV2 DNA shedding began at age 9-11 weeks and following consecutive 5-6 weeks in herd-raised pigs. Feces and saliva showed the highest detection rate. In CDCD pigs, PCV2 DNA shedding was detected sporadically by mPCR in the samples collected 1 week post-inoculation and lasted for 4-6 weeks. The PCV2-specific antibody titre slowly increased at 1-2
weeks and peaked at 6-9 weeks after viral excretion began. Cohabitant CDCD pigs, housing with PCV2-inoculated pigs, began shedding after 1-3 weeks of cohabit and maintain the following 3-4 weeks. PCV2-antibodies showed the peak at 8 weeks after cohabitation. The PCV2 shedding patterns of the pigs raising from the multiple-site production system shown obvious limited in the shedding duration and mortality compared with pigs housing in farrow-to-finished system. The data shown above indicates, the duration of PCV2 shedding after viral infection could reach 6 weeks. Multiple-site production system and all-in all-out production management seems block the PCV2 infection among pigs effectively.

並列關鍵字

Porcine circovirus type 2 (PCV2) ； Excretion Pattern ； Prevention Strategies ； Shedding period

參考文獻

邱明堂、蘇保誠、莊孟修、林昭男。台灣地區罹病豬隻中第二型豬環狀病毒感染狀況之調查。台灣獸醫誌。30: 163-168, 2004。

楊程堯、邱明堂、張聰洲、林昭男、蔡敬屏。台灣地區豬呼吸道疾病綜合症相關病原之分析。台灣獸醫誌。33: 40-46, 2007。

楊程堯、邱明堂、張聰洲、蘇秀琪、王佩玲、葉麗君、林嘉鈺、林怡絹。養豬場中第二型豬環狀病毒生物性傳播途徑之探討。台灣獸醫誌。 33: 66-71, 2007。

Allan GM, McNeilly F, Cassidy JP, Reilly GA, Adair B, Ellis WA, McNulty MS. Pathogenesis of porcine circovirus; experimental infections of colostrum deprived piglets and examination of pig foetal material. Vet Microbiol. 44: 49-64, 1995.

Allan GM, McNeilly F, Meehan BM, Kennedy S, Mackie DP, Ellis JA, Clark EG, Espuna E, Saubi N, Riera P, Botner A, Charreyre CE. Isolation and characterisation of circoviruses from pigs with wasting syndromes in Spain, Denmark and Northern Ireland. Vet Microbiol. 66:115-123, 1999a.