Immuno-specificity of Egg Yolk Antibodies against Bovine Rotavirus and Bovine Coronavirus causing Calf Diarrhea

Seong Lee*, Seung Eun Woo**, Sang Rae Lee*** and Jung Woo Kim*Department of Animal Resources and Science, Dankook University*, Institute of Life Science, Danbiotech Ltd.**,National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology***ABSTRACTThis study was performed to produce specific egg yolk antibodies against bovine rotavirus(BRV) and bovine coronavirus(BCV) that are major pathogens causing diarrhea in calves. Chickens were immunized with BRV and BCV intramuscularly in the breast muscle by injection 5 times at two weeks interval. At 6 weeks after the first immunization of BRV or BCV, cross reactivity of each serum derived from BRV- or BCV-immunized hens was tested. Each serum antibody against BRV or BCV was reacted with only specific BRV or BCV antigens. Serum and egg yolk-antibody titers of hens against BRV or BCVwere highest at 8~12 weeks after first immunization. Specific serum and egg yolk-antibody titers against BRV were about 104,000 and 107,000, respectively, and those against BCV were about 145,000 and 155,000, respectively. Hemagglutination inhibition titers in the immunized egg yolk antibodies against BRV and BCV were 5,120 and 1,280, respectively, and were 8 times higher than that in non-immunized control. These results suggested that the immunized egg yolk antibodies could effectively neutralize BRV and BCV. (Key words :Egg yolk antibody, BRV, BCV, Neutralization)