Comparative study of antibody titers obtained from Avinew and La Sota vaccines in broiler chicks with ELISA test

Abstract    Newcastle disease is an important viral disease and its occurrence and virulence in Iran has increased in recent years. Therefore control of this disease through effective vaccination programs is very important. The objective of this study was to compare the effectiveness of La Sota and Avinew vaccines in broiler chicks. In this study, 270 day old Ross broiler chicks were divided into 3 groups with 3 replicates in each group and 30 chicks in each replicate. Avinew and lasota vaccines were used in groups 1 and 2 respectively. Group 3 was the covered group and Newcastle vaccine wasn't used in this group. Breeding conditions were the same in the 3 groups and blood samples were collected the 3 groups and blood samples were collectd on days 1,14,24,34 and 44 for determination of antibody titers obtained from Newcastle vaccines using the ELISA serologic test. The results indicated that in the vaccinated groups, antibody titers increased significantly (

Experimental study on histopathological changes and tissue tropism of Iranian infectious bronchitis serotype 793/B-like virus in SPF chickens

Avian infectious bronchitis virus (IBV) is prevalent in all countries with intensive poultry flocks. This disease is characterised primarily by respiratory signs, but some IBV strains may also infect other organs such as the intestinal and urogenital tracts. The aim of this study was to characterise the histopathological lesions and tissue tropism of Iranian isolate IR/773/2001(793/B) of avian infectious bronchitis virus in different organs of experimentally infected SPF chickens. Forty-two one-day-old, specific pathogen-free (SPF) chicks were divided randomly into two groups (21 chicks to each group). At the age of 12 days, one group was inoculated intra-ocularly with 103 EID50 of the 793/B isolate, and the other was kept as the control group. Tissue samples were collected at 2, 4, 6, 8, 10 and 12 days post-inoculation (PI). The IBV virus was detected in the caecal tonsils and cloaca from the 2nd to the 12th day PI. The virus was also detected in the kidneys from days 4–10 PI and in the bursa of Fabricius from days 4–12 PI. The virus was detected in the trachea, lungs and thymus. The most obvious histopathological lesions were found in the trachea, kidney, lungs and bursa of Fabricius. Amongst the lymphoid tissues, histopathological changes were found most frequently in the bursa of Fabricius. The results of this study indicated that the 793/B serotype of IBV is unlikely to cause mortality, severe clinical signs or gross lesions in infected chickens, but its replication in some tissues including the bursa of Fabricius could render birds susceptible to other micro-organisms