Study on Experimental Infection of Newcastle Disease Virus in Local Breeder Chicks Infected with Infectious Bursal Disease Virus

Clinical signs, macroscopic lesions, virus tissue distribution, shedding and humoral immune responses to virulent Newcastle disease virus in native breeder chicks were studied .One hundred and twenty day-old native breeder chicks were divided randomly into four equal groups. Groups one and two were infected with 103 CID50 infectious bursal disease virus (IBDV) by intra-bursal route on day-old. Groups one and three chicks were infected with 105EID50 virulent ND virus by nasal route on 30th days. Fourth group 4 chicks were kept as uninfected control group. Clinical signs were observed daily after each inoculation. Tracheal and cloacal swabs from four live birds of each group collected on days of two, 5, 10, 15 and 18 post NDV infection and on the same days except days eighteen, four chicks were randomly euthanized and organ tissue samples from brain, trachea, lung, kidney and liver were collected to detect ND virus by RT-PCR method. Clinical signs was more severe in IBDV and ND virus infected group and ND virus was detected from trachea and cloaca swabs for a longer period and mean HI titer to ND virus in these birds was lower. Two-way analysis of variance showed IBD infection significantly affected immune humoral response (P