Infectious Bursal Disease Antibody Levels and Viral Load in Bursa, Faeces, Litter and Dust Following Infection of Commercial Broiler Chickens at 0 and 14 days of Age

Australian endemic IBDV serotype 1 variant strain 02/95 was quantified using qRT-PCR in bursal tissues of commercial Ross broiler chickens inoculated orally at days zero and 14 of age and maintained to 28 days post infection (dpi). High levels of viral RNA were detected at 7, 14, 21 and 28 dpi in birds challenged at day 14 but only at 21and 28 dpi in birds challenged at day zero. Challenge at both ages induced a significant antibody response relative to unchallenged controls. Virus was detected in faeces prior to day 7 and again at 28 dpi in both challenge groups, but not during the intervening period. IBDV was also successfully quantified by qRT-PCR in poultry dust and litter from the infected groups.