Efficacy Study on Passive Protection with Egg Yolk Antibodies against Riemerella anatipestifer Infection in Ducks and Geese

CF Yu , TS Huang

Animal Health Research Institute, Council of Agriculture, Executive Yuan

Abstract

The safety, efficacy and duration of protection of egg yolk antibodies against serotype 2 of Riemerella anatipestifer (RA) infection were studied in ducklings and goslings. Various tests on bivalent egg yolk antibodies against serotype 1 and 2 of RA infection have been conducted. The results showed that both bivalent egg yolk antibodies isolated from chicken or duck lines were efficacious against homologous challenges. The passive immunization protection stayed for five to ten days in Peking ducks, Muscovy ducks and white Roman geese. In addition, the bivalent antibodies were effective for treatment for challenges less than 107 CFU/mL. However, there was no cross protection against heterologous serotype challenges. Considering the production cost, source of pathogen-free lines as well as reproducibility of efficacy tests, we have chosen chicken lines as a biofactory for future antibody production. Egg yolk antibodies generated in these could provide passive protection against the same serotypes of RA infections in ducks and geese field populations in the future.

Keywords: Riemerella anatipestifer infection, egg yolk antibody, efficacy, treatment, cross-protection.