|LILLEHOJ HYUN S|
Submitted to: Misset World Poultry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/1/1994
Publication Date: N/A
Interpretive Summary: Avian coccidiosis causes severe intestinal damage and $450 million in annual economic losses. Vaccines for coccidia are not available. Development of new control strategies are being investigated by ARS scientists. In this study, improvement of host immunocompetence through genetic selection is suggested as a control of coccidiosis. This is based upon the observation that performance-related traits such as reproduction, hatchability, growth rate, feed use efficiency, and body weight are influenced by the B-complex genes. This information will help to develop ways to genetically improve chicken stocks for better immunocompetence.
Technical Abstract: In view of the complexity of the parasite life cycle and the involvement of the immune response and host genetics, the development of an efficient control strategy against coccidia will probably require more than one mechanism. Furthermore, innate and acquired immunity to microbes depends upon host factors such as age, immune status, and genetic background of the host. The denoted factors can signicantly influence the effective operation of the immune system. The B-complex represents a significant host factor in production characters and disease resistance of chickens. Thus, chickens with a known B-genotype will have a predicatable level of immune competence and disease resistance for the relevant pathogens. However, other genes also have a profound effect on different aspects of the immune response and reproduction traits in chickens. Enhancement of natural immunity can be made possible through the injection of lymphokines, selective breeding of immunocompetent genetic stock, or the insertion of genes that enhance natural immunity of chickens. However, most efficient disease management may depend upon a combination of measures such as medication, vaccination, and genetic improvement.