Eggshell apex abnormalities in a free-range hen farm with mycoplasma synoviae and infectious bronchitis virus in Rio de Janeiro state, Brazil

Fc Dos Santos,Ls Machado,Er Do Nascimento,Vla Pereira,Cc Da Silva,Ml Barreto,Mdm Brandão,Mv Soares

doi:10.1590/1516-635x1602101-104

Fc Dos Santos, Ls Machado + Show 6 more

Open Access

https://doi.org/10.1590/1516-635x1602101-104

Copy DOI

Abstract

A farm with 3,000 free-range hens between 24 and 65 weeks of age was investigated. These hens were separated in small flocks of 400 to 700 birds, presenting 10 to 23% egg production reduction. Twenty serum samples were collected during the period of drop in egg production and three weeks later for the investigation of Mycoplasma synoviae (MS), M. gallisepticum (MG) and Infectious Bronchitis Virus (IBV) antibodies using ELISA. At the time of the second collection, egg production had resumed to normal levels; however, with 10.23% of the eggs showed eggshell abnormalities limited to the apex. Eggshell strength was significantly different between normal and those with eggshell apex abnormalities, but not other egg-quality parameters. ELISA tests showed that MS and IBV titers increased during the evaluated period. MS infection was confirmed by culture and by PCR of tracheal swabs. All samples were negative for MG by ELISA and PCR. Further studies with larger samples to ensure the occurrence of this disease in industrial layer flocks in Brazil are under way.

Highlights

In 2008, a new abnormality in the eggshell of chicken eggs was identified in The Netherlands (Feberwee et al, 2009b), followed by reports of the same abnormality in Italy (Catania et al, 2010), Germany (Ranck et al, 2010), and England (Strugnell et al, 2011)
This case report describes the occurrence of eggs with eggshell apex abnormalities (EAA) in freerange hens positive for Mycoplasma synoviae (MS) and Infectious Bronchitis virus (IBV) in Brazil
A total of 718 eggs were analyzed for the quantification of abnormal eggs laid, out of which, 46 eggs with EAA and other 60 normal eggs were investigated for egg quality tests and approximate weights

Summary

Introduction

In 2008, a new abnormality in the eggshell of chicken eggs was identified in The Netherlands (Feberwee et al, 2009b), followed by reports of the same abnormality in Italy (Catania et al, 2010), Germany (Ranck et al, 2010), and England (Strugnell et al, 2011). For this reason it was called eggshell apex abnormalities (EAA). A MS strain was isolated from the oviduct of hens producing eggs with EAA and yielded the same abnormalities after experimental infection (Feberwee et al, 2009b). This case report describes the occurrence of eggs with EAA in freerange hens positive for MS and Infectious Bronchitis virus (IBV) in Brazil.

Results

Conclusion