Malabsorption Syndrome in Broiler Chickens

Abstract

A disease syndrome of broiler chickens is described. Affected birds exhibited poor pigmentation of the shanks, decreased weight gains, elevated feed conversions, poor feathering, enlargement of the proventriculus, and a decrease in the size of the gizzard. Reoviruses were isolated from affected chickens from several farms. Signs and lesions similar to those seen in chickens with the field syndrome were reproduced when these isolates were inoculated into day-old chicks with low levels of maternal antibody against viral arthritis. The pathogenicity of the viral isolates was variable. The incidence of lameness was much higher in those groups of chicks injected with these viruses than in the control groups.

Viral proventriculitis in chickens

“…Although some proventriculi from reovirus-infected chicks might appear enlarged (Page et al, 1982;Brugh & Wilson, 1986), reovirus-infected chicks usually do not have proventricular enlargement, nor do they have proventriculitis. In fact, there are no data that establish that reoviruses are capable of causing proventriculitis in chickens (Robertson & Wilcox, 1986;Fletcher, 1988).…”

“…They include low fibre diets (Riddell, 1987), dietary biogenic amines and mycotoxins (Dorner et al, 1983;Brugh & Wilson, 1986;Stewart et al, 1986), reovirus (Page et al, 1982;Brugh & Wilson, 1986), adenovirus (Kouwenhoven et al, 1978), tumour-inducing viruses (Mussman & Twiehaus, 1971;Jackson et al, 1977;Bagust et al, 1979;Payne & Purchase, 1991;Witter, 1991), Cryptosporidium (Goodwin, 1995) and idiopathic proliferations of cells interpreted to be histiocytes (Hafher et al, 1995). The purposes of the present study were to examine proventriculi of broiler chicks for lesions, and to classify and record the incidence of these lesions.…”

Investigations into the role of reovirus in the malabsorption syndrome

“…All four strains caused clinical signs and lesions comparable with those described for the syndrome. Page et al (1982) isolated two reoviruses from intestinal tracts from field cases and upon oral inoculation of one-day-old chicks, signs and lesions similar to those seen in chickens with the field syndrome were reproduced. Hieronymus et al (1983) isolated five reoviruses of three distinct serotypes from intestines from broilers with malabsorption syndrome.…”

“…Considering that maternal immunity against reovirus is transmitted to the progeny of breeders vaccinated with serologically different reoviruses, the authors suggested that suitable strain(s) for the production of a vaccine might be indicated. This suggestion, based on the reproduction of the syndrome as described by Page et al (1982), was perhaps the scientific basis for immunisation of broiler parents with oil emulsion vaccines containing inactivated reovirus to protect broilers from malabsorption syndrome in the USA. Rosenberger (1983) isolated reoviruses from joint swabbings, bone marrow, liver, spleen and tendons, which varied from highly pathogenic to innocuous.…”

Rapid passage of avian reovirus in one‐day‐old chicks: Clinical and virological findings

“…Avian reoviruses have been isolated most frequently from chickens affected with tenosynovitis/viral arthritis (van der Heide, 1977;Kibenge and Wilcox, 1983) and, recently, with runting/stunting or malabsorption syndrome (Kouwenhoven et al, 1978;Page et al, 1982;Pass et al, 1982;Hieronymus et al, 1983). These viruses have been isolated less frequently from birds with other pathological conditions involving the enteric (Dutta and Pomeroy, 1967;Deshmukh andPomeroy, 1969), respiratory (Fahey and Crawley, 1954), circulatory (Spradbrow and Bains, 1974;Bagust and Westbury, 1975;Jones, 1976) and lymphoid tissues (Bagust and Westbury, 1975), and from clinically normal birds (Robertson et ah, 1984).…”