01836naa a2200193 a 450000100080000000500110000800800410001910000180006024501140007826000090019252012880020165000110148965000090150065300140150970000160152370000180153970000150155777300700157217837182017-04-06       1987    bl ---       0--  u    #d1 aLIESS, B. von  aHaufigkeit des Auftretens persistierender BVD-Virusinfektionen und ihre Auswirkungen in der Rinderpopulation.  c1987  aBlood samples from cattle were examined for BVD virus by cultural isolation from bufty coats in order to detect viraemia and amongst the viraemic animals persistent infections. A total of 3741 donor cattle were categorized according to their selection and so were the 235 viraemic and 19 persistently infected animals. The incidence of persistent infections with BVD virus being less than 1% was calculated from a group of 2317 animals selected without bias in more than 1000 breeding herds in Northern Germany (Category A). Of 837 animals clinically suspect of BVD 185 were viraemic (Category B). In Category C, 16 of 539 cattle proved to be vieramic in ten herds after BVD occured there clinically, e. g. by abortion or CNS syndrome. Further impacts of persistent BVD virus infections were allowed to be studied in two herds after BVD live virus vaccinations resulting in twelve vieramic offspring from dams seronegative when inoculated. Of 17 persistently infected animals eleven were sacrificed and necropised. Apart from enteritis, brochopneumonia and thymus atrophy, BVD virus antigen was demonstrated in the brains of seven animals. The histological findings in cerebral cortex of eleven animals and spinal cord of four animals were perivascular infiltration and satellitosis.  acattle  aGado  aVirus BVD1 aFREY, H. R.1 aTRAUTWEIN, G.1 aPETERS, W.  tDeutsche Tierarzliche Wochenschriftgv.94, n.10, p.583-585, 1987.