Molecular typing of fowl adenovirus associated with gizzard erosion in commercial layer grower chicken in Tamil Nadu

Abstract

The present study was undertaken to characterize fowl adenovirus associated with commercial layer grower chicken showed gizzard erosion. Ninety four commercial layer grower chicken flocks from Namakkal districts of Tamil Nadu had shown reduced feed intake, reduced weight gain, uneven growth and mortality of 0.3 to 7.7%. On postmortem examination of affected birds showed mild to severe gizzard erosion, blackish discoloration of gizzard contents, pale liver and no major lesions were seen in other organs. Total DNA was extracted and 897 bp fowl adenovirus specific hexon gene was amplified by PCR. Out of 94 flocks screened seven flocks were found positive of fowl adenovirus. Chicken embryo liver cell culture was prepared to isolate field fowl adenovirus from suspected flocks. Concurrent infection of chicken anaemia virus (CAV) was also screened by PCR for 419 bp VP2 gene of CAV and found that all the seven flocks which were PCR positive for FAdV also found positive for CAV. Sequencing and phylogenetic analysis of 897 bp FAdV hexon gene revealed that, it was belonged to FAdV serotypes 2 and 3 of species D.