The study period carried out from 25 April 2018 till 21 May 2019 through the rearing and production period including totally of 24000 birds (20800 females, 3200 males). The number of tested blood samples was 452 divided to 255 samples at the rearing period, 143 samples at the production period and 54 samples of offspring. The results of antibodies titer in the sera of non-vaccinated broiler breeders obtained by ELISA showed the maternal derived antibodies titer for 28 samples at 0-5 week/day of age was 5716±612.7, this titer decreased gradually at 3-1 week/day age till to 1075±234) Then the titer was elevated increasingly after vaccination with both live attenuated and inactivated vaccines and reach to peak 37512±2049.4 at 20-1 week/day age. Whereas the bimodal graduation of antibodies titer showed at production period till to end of study. The mean of maternally antibodies titer in the tested sera of the offspring chicks 0-1 week/day that hatched from parent flocks at 32, 39 and 48 weeks of age was 9012±872.4, 6591±368.1 and 4831±982.7 respectively. Thus, we concluded the repetitive vaccination of broiler breeders flock with live vaccine as well as inactivated vaccine is very necessary in endemic areas and ELISA is a good serological test for following, checking and monitoring of immune status of poultry flocks periodically.
Avian reoviruses can infect birds without any clinical signs of infection, the infection may associate with different manifestations including viral arthritis/tenosynovitis and malabsorption syndrome. The objective of this study was to use advance methods representing by molecular methods (RT-PCR, RT-qPCR) in the diagnosis of ARV infection in broiler breeders' flocks. A 4 flocks of broiler breeders (ROSS breed) 39 weeks age with approximately10% morbidity rate due to Avian Reovirus (ARV). The clinical examination of 16 infected birds revealed unilateral lameness and swelling of hock joint. Blood samples were collected from wing vein of infected birds. Sera were tested for antibodies titer against ARV and Mycoplasma synoviae
(MS). 5 of 16 positive samples were selected randomly for amplification by RT-PCR and RT-qPCR. The results showed in postmortem examination of infected birds, unilateral arthritis with visible joint lesions. Antibodies titer measured by ELISA in the sera of birds after 4 and 20 weeks of infection with ARV was positive and high. In RT- PCR1 of 5 samples gave positive reaction for amplification while in RT-qPCR all five samples gave positive results for amplification in comparison with +ve and -ve control.
This study was conducted for diagnosis and description of the pathological changes of AIV-H5 as the causative pathogen in Iraqi broiler farms. The current study was carried out on 84 broiler farms. Infected birds were tested for detection of the AIV infection from the tracheal swabs by rapid chromatographic AIV type A and H5 test kits. In RRT-PCR 8 samples (8 farms) of Trachea were selected to be tested by this assay. Samples of trachea, lung, and spleen from the dead birds with natural AIV-H5 infection were submitted for histopathological examination. seventy-two out of 84 farms tested for AIV-Type A gave positive results, and 58 out of 72 positives for type A-AIV gave a positive result for H5 antigen in a rapid chromatographic strip. The main gross lesions in the trachea of infected birds were severe congestion and hemorrhage. In the RRT-PCR assay, 8 out of 8 samples gave a distinct positive result for this test. The microscopic histopathological examination of infected tracheas showed obvious desquamation of lining epithelium with complete loss of cilia associated with congestion of blood vessels in lamina properia. Infected lungs revealed diffuse alveolar damage and severe multifocal vascular congestion. There was deposition of fibrinous material in the splenic tissue associated with the disappearance of the germinal centers. Thus, we concluded that AIV-H5 infection causes severe pathological and histopathological changes as a result of systemic infection. The RRT-PCR assay was highly sensitive and specific for the detection of highly pathogenic avian influenza virus subtypes.