4SWENSON S L, HILL H T, ZIMMERMAN J J,et al. Excretion of porcine reproductive and respiratory syndrome virus in semen after experimentally induced infection in boars [ J ]. J Am Vet Med As- soc, 1994, 204 (1) :1943 -1948 .
6Cho J G, Dee S A. Porcine reproductive and respiratory syndrome virus[J]. Theriogenology, 2006, 66: 655-662.
7Keffaber KK.Reprodutive failure of unknown etiology[J].Am.Assoc Swine Pract Newsletter,1989,1:1-10.
8Teifke JP,Dauber M,Fichtner D.et al.Detection of european porcine reproductive and respiratory syndrome virus in porcine alveolar macrophages by two-colour immunofluorescence and in situ hybridization immunohisto-chemistry double labelling[J].J Comp Pathol,2001,124(4):238-245.
9Bilodeau R,Dea S,Sauvageau RA.et al.Porcine reproductive and respiratory syndrome Quebec[J].J Vet Rec,1991,129(5):102-103.
10Wensvoort G.Lelystad virus and the porcine epidemic abortion and respiratory syndrome[J].Vet Res,1993,24(2):117-124.
