Defense mechanisms of the avian gastrointestinal tract.
D000818:Animals; D001715:Bird Diseases / Q000503:physiopathology*; D001717:Birds / Q000502:physiology; D004064:Digestive System / Q000503:physiopathology*; D004068:Digestive System Physiological Phenomena; D005767:Gastrointestinal Diseases / Q000503:physiopathology / Q000662:veterinary; D007239:Infections / Q000503:physiopathology*