Abortion and calf mortality in Danish cattle herds

abortion aborto aetiology analyse microbiologique avortement bovin calves cattle danemark denmark dinamarca disease surveys encuestas sanitarias etiologia etiologie foetal death ganado bovino hatos herds infection microbiological analysis mort du foetus mortalidad mortalite mortality muerte fetal necropsie pneumonia pneumonie postmortem examination septicaemia septicemia septicemie ternero troupeau veau