title: Investigation of causative agents of bovine respiratory tract disease in a beef cow-calf herd with an early weaning program.
abstract: Serum samples were collected from early weaned fall calves shortly after the onset of respiratory tract disease. Antibody titers to infectious bovine rhinotracheitis (IBR) virus, parainfluenza type 3 (PI-3) virus, bovine viral diarrhea (BVD) virus, bovine adenovirus type 3 (BAV-3), and bovine respiratory syncytial virus (BRSV) were determined on paired (acute and convalescent) serums. Seroconversion rate (a fourfold or greater rise in antibody titer) for IBR virus was 4.3%, PI-3 virus--16.3%, BVD virus--9.6%, and BAV-3--2.2%. Seroconversion for BRSV was 45.4%. An increased rate of seroconversion for IBR, PI-3, and BVD viruses and BAV-3 was observed in the presence of BRSV seroconversion. These results suggest that BRSV may facilitate infection by other viruses. Results of virus isolation procedures from these calves were negative.
mesh_terms: D000256:Adenoviridae / Q000276:immunology; D000818:Animals; D000914:Antibodies, Viral / Q000032:analysis; D002417:Cattle / Q000276:immunology; D002418:Cattle Diseases / Q000276:immunology / Q000382:microbiology*; D001908:Diarrhea Viruses, Bovine Viral / Q000276:immunology; D005260:Female; D007242:Herpesvirus 1, Bovine / Q000276:immunology; D010224:Parainfluenza Virus 3, Human / Q000276:immunology; D012136:Respiratory Syncytial Viruses / Q000276:immunology; D012141:Respiratory Tract Infections / Q000276:immunology / Q000662:veterinary*; D010253:Respirovirus Infections / Q000276:immunology / Q000662:veterinary; D014886:Weaning
chemical_list: D000914:Antibodies, Viral