• Monthly Korean Chicken
• /
• v.15 no.10
• /
• pp.84-87
• /
• 2009

• KOREAN POULTRY JOURNAL
• /
• v.14 s.154
• /
• pp.96-97
• /
• 1982

• Asian-Australasian Journal of Animal Sciences
• /
• v.8 no.1
• /
• pp.1-6
• /
• 1995

This study represented an endeavor to observe clinical signs and pathological lesions in broiler chicks suffering from experimental Infectious stunting syndrome(ISS). One hundred and twenty day old broiler chicks were divide randomly into two equal groups i.e. control (A) and inoculated (B). At day one of age each chick of the groups (A and B) was dosed with one ml of either tryptose phosphate broth or prepared inoculum respectively. Chicks of both the groups were housed separately under similar standard management. Inoculation induced characteristic clinical changes in birds of treatment group like of brownish diarrhea, lameness, feather developing problems and paleness of combs, wattles and shanks. By day-29 of the experiment all the stunted birds from group-B and an equal number of birds from group-A were slaughtered. These birds were examined thoroughly to record the gross changes in various structures and then the severely affected organs were processed for histopathological examination. The skeletons of affected birds were brittle, keel bones showed quite prominence while the muscles and subcutaneous tissues were almost devoid of fat. Grossly it was observed that pancreas, spleen and bursa of Fabricius were severely atrophied while the intestines were ballooned with undigested feed and gases. Histopathological examination of pancreas and spleen revealed a classical picture necessary for understanding the pathogenesis of the syndrome. The acivar cells of pancreas were atrophied and underwent vacuolation, degeneration and vecrosis. The zymogen granules were almost absent from the acinar cells. A characteristic change was an inflammatory reaction in one or more pancreatic ducts where the epithelium and fibrous tissues occluded the lumen of the ducts and led to the obstruction in pancreatic drainage.

• Korean Journal of Veterinary Service
• /
• v.42 no.4
• /
• pp.237-243
• /
• 2019

Avian reovirus (ARV) is the pathogenic agent of tenosynovitis and malabsorption syndrome in broiler, which has caused significant economical losses due to poor feeder efficiency and stunting. In order to determine the prevalence of ARV infection in poultry farms in Jeonbuk province, Korea, we performed a surveillance study by testing 179 cecal samples from 131 broiler farms for virus detection, and 1,181 serum samples from 33 broiler farms (n=292) and 22 broiler breeder farms (n=1,525) for antibody detection in the province. Virological examination using RT-PCR showed that ARV were detected in 26.0% of the tested farms (34/131),with the highest positive rates in broilers of 6 days old or more in summer season. In serological test using ELISA, broiler and broiler breeder farms examined were all ARV antibody positive. In broiler, the positive rate and antibody titers showed a tendency to decrease with age in contrast to those of broiler breeders. Our results indicate that ARV is ubiquitous in broilers and broiler breeders in the province.

• Korean Journal of Poultry Science
• /
• v.35 no.1
• /
• pp.85-99
• /
• 2008

Avian reovirus (ARV) is a causative agent of viral arthritis/tenosynovitis, and malabsorption syndrome in broiler. The characteristics of malabsorption syndrome caused by ARV are diarrhea, poor feed conversion and stunting. Therefore, ARV infection has been recognized as one of the most important disease in the poultry industry because of economical losses. However, few study of ARV infection in broiler industry has been conducted in Korea. To evaluate the presence of ARV infection in broiler farms, epidemiological survey such as serological test and virus isolation has been conducted. For the serological survey using ELISA method, we selected five broiler farms which were located at different area and had a history of growth retardation, lameness, diarrhea and poor feathering. From these farms serum samples were collected at 1 day, 14 days and market age. All these farms had no history of vaccination against ARV. In addition to serological survey, we tried to isolate ARV from birds of designated farms at market age and collected feces and tissue samples such as cecal tonsil, intestine and liver. We were identified ARV by RT-PCR and transmissible electron microscopy. The samples were inoculated into 9-day-old embryonated eggs via the chorioallantoic membrane to observe the pock formation. For the pathogenicity test of ARV isolates, we inoculated with the isolates to the right footpad of 3-week-old SPF chicks and observed clinical signs and pathological changes for 14 days after challenge. Most broilers sampled for serological survey have maternal antibodies which were widely distributed at 1 day and decreased by 14 days. However, at the market age several broiler farms showed fairly high antibody titer against ARV. This increase of antibody titer at market age means the possible infection of ARV during the grow-out period. Among total 15 samples for the isolation of ARV. 2 samples were positive by RT-PCR and finally identified as a ARV. We inoculated these isolates in the SPF birds and observed that the antibody titer was increased from 7 days after challenge. However, we did not find any clinical signs both control and challenge groups. Based on the above results, it is clear that the ARV infection has been circulated in the broiler industry and caused significant economic losses. Further study is needed to evaluate the virulence of the isolates in the digestive system of broiler and the molecular characteristics of isolates.