Investigation of Enteric Viruses Associated With Runting and Stunting in Day-Old Chicks and Older Broilers in Southwest Nigeria

Abstract

Enteric viruses are known to have significant economic impact on poultry, especially broiler chicken flocks, because of production losses attributable to poor feed conversion and weight gain. To sustain the Nigerian poultry industry that contributes significantly to the livestock sector of the economy, there is a need to investigate commercial broiler flocks in the country for the presence of enteric viruses causing runting and stunting, growth retardation, and hatchery diseases. Gut contents were collected from 158 day-old and six 14-week old runted/stunted broiler chickens in commercial farms (ten) and hatcheries (six) located in Southwest Nigeria. The samples were examined for the presence of chicken astrovirus (CAstV), avian nephritis virus (ANV), avian rotavirus (AvRV), chicken parvovirus (ChPV), and turkey astroviruses (TAstV-1 and−2) by polymerase chain reaction (PCR) and reverse transcriptase-PCR (RT-PCR) whereas avian reovirus (ARV) and fowl adenovirus (FAdV) by virus isolation (VI), RT-PCR, and PCR. While CAstV was detected in all the birds (100%), sporadic detection of ANV (5%), and ChPV (5%) was observed in day-old and/or older birds. Four isolates were obtained by VI with one isolate being ARV positive and other three FAdV positive by RT-PCR and PCR, respectively. These findings strongly suggest CAstV as a major cause of runting and stunting as well as hatchery condemnations in commercial broilers in Southwest Nigeria, although co-infections with ANV, FAdV, ARV, and ChPV cannot be ruled out. In addition, the possible vertical and horizontal transmissions of these viruses are discussed.

Detection and characterization of chicken astrovirus associated with hatchery disease in commercial day-old turkeys in southwestern Nigeria

“…The strain detected in the condemned turkey poults in this study also belongs to the Bi subgroup and is 91% identical to the FP3 and 11672 isolates in its capsid gene nucleotide sequence and 96.5% and 96.7% identical to the FP3 and 11672 isolate, respectively, in its capsid protein amino acid sequence. The poult CAstV strain identified in this study is essentially identical (99.1% and 99.7% based on full-length capsid nucleotide and amino acid sequence comparisons, respectively) to the CAstV strain detected in multiple cases of chick hatchery condemnations in southwestern Nigeria due to runting and poor thrift [10], and this high level of homology to strains associated with hatchery diseases in chicks suggests the presence of a pathogenic strain in poults, potentially vertically transmitted.…”

“…Samples consisting of intestinal contents from 97 live, poorly performing day-old commercial turkey poults purposively collected from five commercial hatcheries and five farms in Oyo and Osun States, southwestern Nigeria, were collected and processed to give a final 10% (w/v) suspension as described previously [ 10 ].…”

“…Studies have implicated several viruses, including astroviruses, reoviruses, adenoviruses, coronaviruses, Handling Editor: Reimar Johne. and rotaviruses, as causative agents of enteric infections in chickens and turkeys, which produce different clinical manifestations depending on whether they occur as single or multiple infections [4,[7][8][9][10]. These infections have considerable economic impact due to reduced weight gain and feed intake, which lead to opportunistic infections in affected birds.…”

“…These infections have considerable economic impact due to reduced weight gain and feed intake, which lead to opportunistic infections in affected birds. In addition, they usually cause a mild gastroenteritis in most species, although several reports have associated astroviruses with acute disease in the young of multiple species and more-severe diseases in poultry [8][9][10][11].…”

Seroprevalence and risk factors of avian reovirus in backyard chickens in different areas of Mymensingh district in Bangladesh

“…ARV, the causal agent of ARV infection in chickens, plays a crucial role in reducing egg production [ 10 ]. Among the 15 genera of the Reoviridae family, genus Orthoreovirus belongs to two main principle groups, namely ARV and mammalian reovirus [ 11 – 13 ].…”