A Comparative Study of the Pathogenesis of Malabsorption Syndrome in Broilers

Abstract

Five malabsorption syndrome (MAS) homogenates from The Netherlands and Germany were used to reproduce MAS in broilers. We studied the histopathology after inoculation of 1-day-old broiler chicks and the agents that might be involved. Generally, the MAS homogenates induced signs that differed in severity and pathobiology. We could distinguish and classify the inoculated groups best by histopathology: proventriculitis, lesions in the small intestines in combination with proventriculitis, or lesions of the small intestines only. Lesions in the small intestine had more impact on weight gain depression than lesions in the proventriculus. In three out of five inoculated groups, microscopic lesions of the pancreas were found. Reovirus was detected in the inoculated groups by virus isolation and seroconversion, and reoviral antigen was detected by immunohistochemistry of the small intestine. Also, enteroviruslike particles were detected in three of the five inoculated groups, although not in the most affected group. Additionally, bacteriophages and bacteria (hemolytic Escherichia coli, Pasteurella hemolytica, and Enterococcus durans) were isolated from inoculated chicks. The role these agents play in pathogenesis of MAS is still unsolved.

Circulation and phylogenetic relationship of chicken and turkey-origin astroviruses detected in domestic ducks (Anas platyrhynchos domesticus)

“…Turkey (TAstV-1 and TAstV-2) and chicken-origin (CAstV and ANV) astroviruses are associated mostly with enteric diseases affecting young birds. They are common viral agents of poult enteritis and mortality syndrome in turkeys, and runting and stunting syndrome in chickens (Songserm et al, 2000;Baxendale & Mebatsion, 2004;Pantin-Jackwood et al, 2006Smyth et al, 2007;Spackman et al, 2010). Both syndromes are characterized by diarrhoea, impaired digestion, malnutrition and loss of weight gain in affected birds (Moser & SchultzCherry, 2008).…”

Detection and characterization of avian nephritis virus in ducklings

“…This virus is associated with diarrhoea, retarded growth, tubulonephrosis, interstitial nephritis, uricosis and death of primarily young chicks Shirai et al, 1991). ANV is known to be one of the aetiological agents of RSS (Goodwin et al, 1993;Songserm et al, 2000;PantinJackwood et al, 2006) and the susceptibility to ANV increases if the chickens are immunosuppressed (Narita et al, 1990a).…”

Malabsorption syndrome in broilers

“…MAS affected chickens have grossly pale and distended small intestines containing mucoid contents. The principal lesions are found in the mucosa of the small intestine and are characterized by cyst formation in the crypts of Lieberkühn and atrophy of the intestinal villi (Songserm et al, 2000). Pancreatic and proventricular lesions are reported in field cases (Sinclair et al, 1984), however, these lesions are rarely detected in experimentally induced MAS (Reece and Frazier, 1990;Songserm et al, 2002b).…”

“…In Figure 1 lesions in the jejunum are shown from experimental induced MAS. Using this model the pathobiology was studied of different intestinal homogenates obtained from chickens affected with malabsorption syndrome from different field cases in the Netherlands and Germany (Songserm et al, 2000). MAS was induced by oral inoculation of newly hatched chickens with 0,5 ml of intestinal homogenate obtained from two-week old MAS affected stunted chickens.…”

“…and the supernatant was collected and frozen at -70°C until use. The frozen material was thawed immediately before inoculation of the chickens (Songserm et al, 2000). It was observed that not all inoculated homogenates gave the same severity in lesions in the small intestine and the same growth retardation.…”