Detection of Mycoplasma synoviae antibodies in day-old chicks using rapid serum agglutination assay and enzyme-linked immunosorbent assay

Mycoplasma synoviae antibodies detection using rapid serum agglutination (RSA) assay and enzyme-linked immunosorbent assay (ELISA) is considered as the suitable screening tool in chicken flocks. Both RSA assay and ELISA have performed an ability to detect an antibody formation during mycoplasma infection due to their sensitivity in detecting both IgM and IgY. However, the IgY is the major antibody isotype transferred from the hen to the newly hatched broiler chick via egg yolk. The amount of maternal IgY circulating in the chicks’ serum is approximately 30% of the IgY level present in the hen’s bloodstream. This study was conducted to evaluate performance of serological assays; RSA assay and ELISA; for detecting the M. synoviae antibodies in day-old chicks which reflect maternal antibodies. RSA assay was tested using a commercial M. synoviae antigen (Nisseiken Co., Ltd., Japan) and ELISA was performed by using the commercial M. synoviae indirect kit (ProFlock, Synbiotics Corporation, USA). Serum samples of day-old-chicks, originating from MS-H vaccinated parent flocks, were 97.5% sero-positive for M. synoviae antibodies examined by RSA assay and ELISA, with a mean ELISA S/P ratio of 1.589. The result demonstrated that both RSA assay and ELISA are reliable serological tools for detecting maternal-derived antibodies (IgY) in the serum of day-old chicks which could indicate the serological status of M. synoviae in the parent flocks.