Epidemiological study of enteric viruses in broiler chickens: comparison of tissue culture and direct electron...

The intestinal and caecal contents of chickens from 102 broiler flocks affected by enteric and associated problems were analysed. The second week of life was found to be the most important in the onset of clinical signs of malabsorption shown by the presence of uneven flocks, growth retardation and enteritis problems, but one-week-old flocks frequently presented similar problems. Some cases of feather aberration were observed, mainly in flocks of two weeks of age. From the third week, enteric problems were less acute. Viral particles were found in 67% of the samples by examination by electron microscope and in 52% by cell culture isolation. By complementing the two methods the viral recovery was increased to 85% of the samples. Four virus types were identified: reovirus, entero-like virus, rotavirus and adenovirus. Entero-like virus was mainly found in the first two weeks of life, whilst reovirus and rotavirus were principally found from the second week on. Adenovirus was found infrequently but this may have been a reflection of the mean age of the affected flocks which was only 12 days.