Fig. 3.

Structural defences of the bovine mammary gland. Sagittal section through the distal gland cistern, teat cistern and teat canal of a periparturient Holstein Friesian dairy cow; formalin fixed tissue; scale bar: 10 mm. Teat cistern immunohistochemical inset: Sagittal section through the teat cistern. Scattered intraepithelial lymphocytes expressing CD3 are present multifocally. Immunohistochemical staining for CD3 with haematoxylin counterstain. Fürstenberg’s rosette histological inset: Sagittal section through the teat canal (TC) – distal teat cistern (diamond) junction, Fürstenberg’s rosette (*) of a Holstein Friesian dairy cow 45 dI. Groupings of small to moderate numbers of lymphocytes (L) are present multifocally. Haematoxylin and eosin stain; dI: days involution, with concurrent pregnancy until abortion at approximately 31dI