Studies On Interaction Of Marek's Disease Virus And Reticuloendotheliosis Virus In Co-infected Broilers And Research On MDV Recombinant Field Strain

To understand the interaction between Marek's disease viruses (MDV) and reticuloendotheliosis viruses (REV) in co-infected chickens, their mutual influences on vriremia levels and specific antibody titiers were studied in REV maternal antibody positive (REV-ab+) or negative (REV-ab-) commercial broilers vaccinated with or without MDV vaccine CVI988. The results indicated that,in chickens of vaccinated with CVI988/Rispense,if REV-ab+ to prevent REV viremia, after inoculated virulent MDV, there can′t detected virulent MDV viremia at 5 weeks.But in chickens with REV maternal antibody negative ,both REV and MDV viremia can be detected.In chickens unvaccinated CVI988/Rispense, the REV viremia of REV-ab+ (133.3±326.6) was lower than REV-ab- chickens(1808.3±1413.7), and no difference in MDV viremia level. but their MDV viremia level were higher than vaccinated CVI988/Rispense and REV-ab-(41.67±33.7). This indicated that REV influence MDV viremia through reducing the immune effect.In chickens of REV-ab- , the level of virulent MDV viremia didn′t influence the REV viremia .However, all the REV-ab+ chickens, if were unvaccinated CVI988/Rispense to prevent MDV viremia. MDV mutual influence producted inhibitory effected on chicken′s immune functions, the REV-ab+ chickens can not completely and effectively prevent REV viremia.In chickens vaccinated with CVI988/Rispense,REV viremia influencted MDV specific antibody titers. Especially in 1 and 7 group of REV-ab+ chickens, no REV viremia were detected after inoculated REV. MDV specific antibody titers were 3.8±0.8 (Log10) and 4.2±1.0 (Log10),strikingly highly than 2 and 8 group of REV-ab- chickens 1.8±1.0(Log10)和2.3±1.6(Log10) , REV viremia were detected. The result indicated, REV mutual strikingly producted inhibitory antibody level induced by CVI988/Rispense.In chickens of unvaccinated CVI988/Rispense. Respectively REV-ab+ and REV-ab-. Althrough inoculated at 1 day age, their REV viremia level very...