Objective: To determine the extent of avian leukosis virus subgroup J (ALV-J) infection in Australian broiler breeder flocks, using virus isolation and molecular biological detection. Any resultant ALV-J viral isolates to be characterised by neutralisation cross testing in order to determine antigenic relationships to overseas isolates of ALV-J.
Study Design: Samples of blood, feather pulp, albumen and tumours were obtained from broiler breeder flocks which represented four genetic strains of meat chickens being grown in Victoria, South Australia, NSW and Queensland. Dead and ailing birds were necropsied on farm and samples were collected for microscopic and virological examinations. Virus isolation was carried out in C/O and DF-1 CEF cultures and ALV group specific antigen was detected in culture lysates using AC-ELISA. Micro-neutralisation assay was used for antigenic characterisation of selected isolates. Genomic DNA was isolated from cultured cells, tumours and feather pulp. ALV-J envelope sequences were amplified by PCR using specific ALV-J primers while antibodies against ALV-J were detected by ELISA.
Results: A total of 62 ALV-J isolates were recovered and confirmed by PCR from 15 (31.3%) of 48 breeder flocks tested. Antibody to ALV-J was detected in 20 (47.6%) of the 42 flocks tested. Characteristic lesions of myeloid leukosis caused by ALV-J were found in affected flocks. The gross pathological lesions were characterised by skeletal myelocytomas located on the inner sternum and ribs, neoplastic enlargement of the liver, and in some cases gross tumour involvement of the spleen, kidney, trachea, skeletal muscles, bone marrow, skin and gonads. Microscopically, the tumours consisted of immature granulated myelocytes, and were present as focal or diffuse infiltrations in the affected organs. Virus micro-neutralisation assays demonstrated antigenic variation among Australian isolates and to overseas strains of ALV-J.
Conclusion: ALV-J infection was prevalent in Australian broiler breeder flocks during 2001 to 2003. Australian isolates of ALV-J show a degree of antigenic variation when compared to overseas isolates.
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http://dx.doi.org/10.1111/j.1751-0813.2004.tb12163.x | DOI Listing |
Microbiol Spectr
January 2025
Department of Poultry Science, Mississippi State University, Starkville, Mississippi, USA.
Unlabelled: are Gram-negative, rod-shaped, entero-invasive foodborne bacteria and are frequently detected in chicken houses and facilities of poultry broiler complexes. The objective of this study was to determine the prevalence, critical entry points, and movement pattern of along different stages of a complex. A total of 1,071 environmental samples were collected from 38 production houses (8 pullet, 10 breeder, and 20 broiler), a hatchery, 6 transport trucks, and a processing plant.
View Article and Find Full Text PDFVet Med Sci
January 2025
Department of Agricultural Biotechnology, Faculty of Agriculture, University of Kırşehir Ahi Evran, Kırşehir, Türkiye.
Background And Objective: This study aimed to determine the effects of in ovo formula product injection on hatching parameters, chick quality, small intestinal development and ileum histology of breeder hen eggs.
Methods: A total of 400 fertilised eggs were obtained from the Atak-S parent flock at 42 weeks of age for the experiment. The experiment was designed in two groups: a control group (C), in which no injection was performed, and the other group in which a solution containing formula products at concentrations of 1.
Pol J Vet Sci
June 2024
Campylobacter Laboratory; Division of Veterinary Microbiology and Immunology, Faculty of Veterinary Sciences and Animal Husbandry, Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir (SKUAST-K), Shuhama (Aulesteng)-19006, Jammu and Kashmir, India.
Campylobacter spp. are the leading causes of ovine abortions leading to severe economic losses and a source of bacterial food borne illness in humans, posing a major public health concern. This study reports an increase in Brucella negative abortions in sheep farms in Kashmir, India in the last few years.
View Article and Find Full Text PDFFront Vet Sci
December 2024
Department of Animal Medicine, Production and Health (MAPS), University of Padua, Padua, Italy.
Infectious bronchitis virus (IBV) is a pathogen causing respiratory, renal and reproductive clinical forms in chickens of all ages and productive categories. Its proneness to mutation and recombination gave rise to a plethora of variants differing in terms of pathogenicity, antigenicity, and distribution, with relevant implications for disease control, mainly pursued by routine vaccination, and diagnosis, requiring a steady update of molecular and serological methods. Among the most recent additions to the current phylogenetic classification, based on S1 gene sequencing, is the discovery of an eighth genotype (GVIII), further divided into lineages GVIII-1 and GVIII-2.
View Article and Find Full Text PDFOecologia
December 2024
Department of Evolutionary Ecology, Museo Nacional de Ciencias Naturales, CSIC, José Gutiérrez Abascal 2, 28006, Madrid, Spain.
Accurate identification of decreasing trends is a prerequisite for successful conservation, but can be challenging when immigration compensates local declines in abundance. Here, we show that a potential declining trend driven by low vital rates was overridden and converted into a spectacular increase by massive immigration into the population of a semi-social raptor, the black kite Milvus migrans, breeding in a highly contaminated area near a major landfill. Immigration was promoted by a growing food-base of live prey, coupled with the attraction exerted by the progressive gathering of a large flock of non-breeders at the area, resulting in an "attraction spiral" that lured large numbers of breeders to settle into a contaminated population incapable of self-sustenance.
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