Investigation of avian rotavirus infections in broiler chicks from commercial flocks with different performance efficiency indexes

Abstract

The aim of this study was to investigate and compare the frequency of occurrence of avian rotavirus (AvRV) in poultry flocks according to its Performance Efficiency Index (PEI) scores. A total of 256 individual intestinal content samples of small sized-chicks (runts) with clinical signs of Runting Stunting Syndrome (RSS) and 24 clinically healthy chicks (control) were collected from twelve flocks in southern Brazil with different PEI scores: good ( n = 4, PEI mean = 365); moderate ( n = 4, PEI mean = 342) or poor ( n = 4, PEI mean = 319). Silver-stained polyacrylamide gel electrophoresis (ss-PAGE) was used to detect and identify the AvRV species followed by RT-PCR and sequencing of the partial VP6 gene for species confirmation. AvRV was detected in 83% (10/12) of the flocks and 23.4% (60/256) of the chicks. The electrophoretic migration patterns of viral dsRNA segments were compatible with AvRV species A (AvRV- A), D (AvRV-D) and F (AvRV-F) in 9 (15%), 18 (30%), and 33 (55%) of the positive chicks fecal samples, respectively. The AvRV species identified by ss-PAGE were confirmed by RT-PCR and partial sequence analysis of the VP6 gene. The AvRV detection rate was statistically higher ( p = 0.007) in chicks from flocks with poor PEI when compared to those with good PEI. The occurrence of AvRV-D and AvRV-F was statistically higher in 7 to 9 days old chicks, while AvRV-A was detected only in 13 to 14 days old animals.

Studies on Detection, Prevalence and Molecular Characterization of Avian Rotavirus

“…RVD first detected as virus 132 and rotavirus-like viruses (McNulty et al 1981) has been reported from many places, including a report from Nigeria (Pauly et al 2017). RVD was identified as one of the causes in the pathogenesis of runting and stunting syndrome having a high negative impact on the poultry sector (Otto et al 2006, Gallego et al 2022. Recently, rotavirus has been found to be the single causative agent of young pigeon disease syndrome with high mortality (Harzer et al 2021).…”