[Mastitis in heifers [Streptococcus dysgalactiae]]

aetiology bacteria coliforme bovine mastitis coliform bacteria dairy hygiene danemark denmark dinamarca disease surveys encuestas sanitarias environmental factors etiologia etiologie facteur du milieu factores ambientales hatos heifers herds higiene de la leche infection mammite bovine novilla staphylococcus aureus streptococcus agalactiae streptococcus uberis troupeau