Causes of Runting-stunting Syndrome in Chickens Remain Elusive10 December 2013
SOUTH KOREA - Researchers in Chungbuk found a number of viruses present in broiler on farms with a history of enteritis resulting in runting-stunting syndrome, with half the farms having at least two of the viruses present.
Researchers at Chungbuk National University carried out a molecular survey of enteric viruses on commercial chicken farms with a history of enteritis.
They found several enteric viruses in different combinations on the farms studied.
Several enteric viruses have increasingly received attention as potential causative agents of runting-stunting syndrome in chickens, according to B.S. Koo and colleagues in the journal, Poultry Science.
They performed a molecular survey was performed to determine the presence of a broad range of enteric viruses, namely chicken astrovirus (CAstV), avian nephritis virus (ANV), chicken parvovirus (ChPV), infectious bronchitis virus (IBV), avian rotavirus (AvRV), avian reovirus (ARV) and fowl adenovirus (FAdV), in intestinal samples derived from 34 commercial chicken flocks that experienced enteritis outbreaks between 2010 and 2012.
Using techniques such as PCR and reverse-transcription PCR, enteric viruses were identified in a total of 85.3 per cent of investigated commercial chicken flocks in Korea.
Furthermore, a number of combinations of two or more enteric viruses were simultaneously identified in 51.7 per cent of chicken farms positive for enteric viruses.
The rank order of positivity for enteric viruses was as follows: ANV, 44.1 per cent; CAstV, 38.2 per cent; ChPV, 26.5 per cent; IBV, 20.6 per cent; ARV, 8.8 per cent; AvRV, 5.9 per cen, and FAdV, 2.9 per cent).
Additionally, other pathogens such as Escherichia coli, Salmonella spp., Eimeria spp, and FAdV were detected in 79 per cent of chicken flocks positive for enteric viruses using PCR, bacterial isolation, and microscopic examination.
Koo and colleagues reported that the results of their study indicate the presence of several enteric viruses with various combinations in commercial chicken farms that experienced enteritis outbreaks.
They added that experimental studies are required to further understand the roles of enteric viruses in runting-stunting syndrome in commercial chickens.
Koo B.S., H.R. Lee, E.O. Jeon, M.S. Han, K.C. Min, S.B. Lee and I.P. Mo1. 2013. Molecular survey of enteric viruses in commercial chicken farms in Korea with a history of enteritis. Poult. Sci. 92(11):2876-2885. doi: 10.3382/ps.2013-03280