Prevalence and pathology of oviduct impaction in commercial white leghorn layer chicken in Namakkal region of India

Abstract

Aim: The avian oviduct is a tubular organ responsible for fertilization, secretion of the components surrounding the yolk and transport of egg in the reproductive tract. Disorders of oviduct may have a great bearing on production potential and incur a heavy loss. A study was undertaken to assess the prevalence and pathological changes of impacted oviduct in commercial white leghorn layer chicken in Namakkal region of India for a period of four years from 2006 to 2009. Materials and Methods: A total of 5145 carcasses of white leghorn layers, above 20 weeks age from 255 flocks were examined for various oviduct abnormalities. Heart blood, liver and oviduct swabs collected upon necropsy from 45 layer chicken from six flocks with oviduct impaction were screened for bacterial agents. Pooled tissue (trachea, lung, spleen, caecal tonsil, kidney and oviduct) samples from impacted oviduct cases were screened for viral agents. Serum samples collected from affected flocks were screened for Newcastle disease virus (NDV), infectious bronchitis virus (IBV) and egg drop syndrome – 76 (EDS-76) virus by haemagglutination inhibition (HI) and Mycoplasma gallisepticum (Mg) and Mycoplasma synoviae (Ms) by ELISA. Flock details and pathological changes were recorded in affected flocks to assess the prevalence and impact of oviduct impaction on commercial layer chicken. Results: The results of the present investigation indicated that the oviduct impaction was responsible for 0.87 % cent of the reproductive tract abnormalities in commercial layers between 21 and 80 wk of age. Egg production drop, morbidity and mortality recorded in the affected flocks were varied from 3 to 8, 0.4 to 1.2 and 0.2 to 0.5 % respectively. The oviduct impaction was commonly noticed above 40 wk old layers and predominantly during colder months. Serum samples collected from three flocks with oviduct impaction were found positive for Mg and Ms infection in ELISA test. Escherichia coli was isolated as a pure culture in 29 birds and concurrent with other bacterial agents in 16 birds. Serotyping of E. coli isolates revealed that O144, O54 and O109 were the predominant types. Necropsy examination of carcasses with impacted oviduct showed emaciation, peritonitis, regression of ovarian follicles and distension of oviduct commonly in the infundibulum and magnum region. The exudate was either large mass with concentric layering on cut section or numerous caesous masses with varying size and shape often mixed with creamy or serosangunious fluid. Histopathological examination of oviduct revealed the presence of lymphoid foci in the epithelial layer with marked atrophy and degeneration of mucosal folds. Conclusions: Impacted oviduct constituted 0.87 % of oviduct abnormality in commercial layer chicken with an overall mortality of 0.5 %. The findings of this study showed that the oviduct impaction might be caused by E.coli in concurrence with Proteous spp., Klebsiella spp., Streptococcus spp. and Mycoplasma.

Keywords

• E. coli
• layer chicken
• mycoplasma
• oviduct impaction
• pathology
• prevalence