Hyperimmune Egg Yolk Antibodies Control Intestinal Poultry Diseases

BELTSVILLE, Md. U.S. Department of Agriculture (USDA) scientists have developed a novel, antibiotic-free method that uses hyperimmune egg yolk antibodies to control intestinal poultry diseases. The antibiotic-free technology involves extracting antibodies from egg yolks from pathogen-free hens or female chickens that have been injected with a vaccine that contains inactivated pathogenic organisms.

Scientists at the Agricultural Research Service Henry A. Wallace Beltsville Agricultural Research Center (BARC) and collaborators from different universities and the Mexican company IASA (Investigacíon Aplicada, S.A.) demonstrated the effectiveness of inducing passive immunity in young birds, which have no immune protection right after hatching, against coccidiosis, a devastating poultry disease. Birds affected by coccidiosis are unable to absorb feed or gain weight. The disease costs the poultry industry more than $600 million in the United States and about $3 billion worldwide each year. Treatments used to reduce the spread of disease include good management practices and live vaccinations. However, antibiotic-free alternatives are important to help fight drug-resistant strains and for organic poultry farmers.

In the study, one-day-old chickens were given feed mixed with spray-dried egg yolk powder prepared from hens hyperimmunized with multiple species of the parasite Eimeria, which causes coccidiosis. The chickens were then exposed to live coccidia parasites. Chickens that had received the hyperimmune egg yolk antibodies gained more weight and shed significantly fewer Eimeria in their feces. The treated birds also had less gut lesions than chickens that did not receive the treatment.

coccidiosis is associated with other pathogens, such as the one that causes necrotic enteritisa prevalent gut disease of poultry," said avian immunologist Hyun Lillehoj, who works in BARCs Animal Parasitic Diseases Laboratory. By controlling one, youre also reducing the impact of the other."