Figure 3.

Passive immunization with hyperimmune egg-yolk antibodies as a prophylaxis and treatment of intestinal microbial diseases in domestic animals. Laying hens are immunized with a microbial virulence factor or an adhesion antigen that can be produced recombinantly in an in vitro high expression system. The immunized hens produce antibodies against the immunogen and transfer the antibodies into the egg-yolk. The antibodies in the egg or the yolk can be prepared in dry form by spray- or freeze-drying and incorporated into the diet. Egg-yolk antibodies have been shown to be highly effective at small dietary inclusion rates for the specific control or prevention of many different intestinal pathogens.