Metabolism and Nutrition I: Vitamins and Minerals

The current studies were undertaken to assess the ability of humoral immune response in breeding hens and the protective immunity provided by administration of purified Salmonella gallinarum (SG) porins to the progeny. Two hundred and ten broiler breeder hens, 53 weeks old, were divided into three groups and subcutaneously immunized via multiple sites at 0 and 10 days with either: a) 10 μg SG porins porins; b) 30 μg of SG porins; or c) control, inoculated with phosphate buffer solution (PBS) without porins. Seven days after the second immunization, the levels of SG-specific antibodies were determined in the serum and fertile eggs collected from hens using an enzyme linked immunosorbent assay. Furthermore, fertile eggs were collected again from hens in all treatments and incubated for 21 days. On day of hatch, chicks were placed in groups of 30 birds per group and gavaged with 20, 100 and 500 LD50 % of SG. Results indicated that purified SG porins induced the production of IgY class antibodies detected in the serum and eggs of SG porin-immunized hens (P< 0.05). In addition, SG porins cross-reacted with porins of Salmonella typhi. Compared to control unimmunized hens, the progeny of immunized hens were protected by 53 to 70% fold against challenges of 20 – 500 LD50 % of SG (P< 0.001). These results suggest that porins of SG as well as those of other Salmonella species participate in the induction of protective immunity, and modulation of humoral immune response is one of the mechanisms involved.