A52-75-2007E.pdf - AgroMedia International Inc

Health32Major advances in disease prevention in dairy cattleCorresponding AuthorLeBlanc, S.J.University of GuelphCollaboratorsLissemore, K.D.University of GuelphKelton, D.F.University of GuelphDuffield, T.F.University of GuelphLeslie, K.E.University of GuelphJournal of Dairy Science (2006) Vol. 89 p. 1267-1279.Dairy herd health management can be defined as the promotion of health,improvement of productivity and prevention of disease within the economicframework of the owner and industry. Given this definition, anyfactor that limits animal performance can be considered a componentof poor health, including poor nutrition, uncomfortable housing, aversivehandling and sub-clinical diseases whose signs may not be readily apparent.This way of thinking about dairy herd health represents an evolutionfrom a focus on treating disease in individual animals to the prevention ofdisease and maintenance of good health across the group, herd and population.The role of the veterinarian has evolved from that of a task-orientedtherapy provider to an advice-oriented consultant on herd management.Veterinarians have increasing applied the principles of epidemiology to themaintenance of herd health and the development of programs to limit diseaseoccurrence and spread within and between herds. These changes inapproach have resulted in decreases in the incidence of milk fever, clinicalrespiratory disease in adult cattle, contagious mastitis and clinical parasitism.They have also facilitated rapid expansion in herd sizes and individualproductivity without concurrent increases in disease occurrence.33Intercellular trafficking of the major tegument protein VP22 ofbovine herpesvirus-1 and its application to improve a DNA vaccineCorresponding AuthorZheng, C.F.Vaccine and Infectious DiseaseOrganizationCollaboratorsBrownlie, R.Vaccine and Infectious DiseaseOrganizationHuang, D.Y.Vaccine and Infectious DiseaseOrganizationBabiuk, L.A.Vaccine and Infectious DiseaseOrganizationvan Drunen Littel-van den Hurk, S.Vaccine and Infectious DiseaseOrganizationArchives of Virology (2006) Vol. 151 p. 985-993.Bovine herpesvirus 1 (BHV-1) is associated with several diseases in cattle,including infectious bovine rhinotracheitis, conjunctivitis, abortion, encephalomyelitis.The virus particle is composed of 4 concentric compartments—thecore which surrounds the viral DNA, the capsid, the tegumentand the envelope. When BHV-1 infects a cell, it releases proteins from thetegument which exert effects on the host cell in preparation for the subjugationof its machinery to replicate the virus. This study demonstratesthe role of one those tegumental proteins (VP22) in being able to spread(trafficking) from cell to cell after initial infection of the host. VP22 is a sequenceof 258 amino acids. It was determined that the 138 amino acidsat one end of the sequence (the C-terminal end) were responsible for thetrafficking role of VP22. DNA vaccines carrying the code for another BHV-1protein (glycoprotein D), fused to the code for the complete VP22 proteinor to that for either end (C-terminal or N-terminal) of the protein, were administeredto mice. The vaccine encoding only the N-terminal end of VP22produced a weaker immune response than either of those that includedthe C-terminal end, verifying the potential of VP22 or its C-terminal portionto enhance DNA vaccine efficacy presumably due to the spread ofthe expressed antigen to a larger number of host cells—possibly antigenpresentingcells.80 Highlights in Canadian Dairy Cattle Research - 2007