title: A follow-up study on bovine rotavirus dissemination among calves of a large dairy herd.
abstract: Rotaviruses had previously been involved in lethal diarrhoea of newborn calves as well as non-lethal diarrhoea in calves aged 6 to 7 weeks in a closed dairy herd comprising 220 heads of cattle. Fifty calves born consecutively were thereafter tested at weekly intervals till 8 weeks old for diarrhoea by clinical judgement of their feces and for rotavirus excretion by ELISA tests. Serum antibodies against rotaviruses were sporadically determined by CF tests. Rotavirus was shown to persist in this herd in widely disseminated form, in seasonal waves, peaking during the second week of age. The first week of life and the third, in this order, ranked next in frequency of dissemination. Silent, non-clinical rotavirus excretion also occurred quite frequently in calves 1 to 3 weeks old. All calves examined possessed maternally-derived antibodies in their blood serum, which according to literature merely exert protective activity as long as present in the unabsorbed state in the gut lumen. Careful colostrum feeding during the first week postponed rotavirus excretion as compared to the earlier onset described in the United States, and milk replacer (devoid of antibody) fed from day 8 onward accounted for the peak of rotavirus infection in the second week of life. It proved impossible to assess the degree of rotavirus coetiology for diarrhoea observed at high frequency.
mesh_terms: D000818:Animals; D000831:Animals, Newborn / Q000382:microbiology*; D000914:Antibodies, Viral / Q000032:analysis; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology* / Q000276:immunology; D003967:Diarrhea / Q000453:epidemiology / Q000662:veterinary*; D005243:Feces / Q000382:microbiology; D007112:Immunity, Maternally-Acquired; D012401:Rotavirus / Q000276:immunology; D012400:Rotavirus Infections / Q000453:epidemiology / Q000276:immunology / Q000662:veterinary*; D012621:Seasons
chemical_list: D000914:Antibodies, Viral