[Defense mechanisms of the bovine mammary gland]

In the mammary gland of cattle there is a complex defense system of non-specific and specific reactions available preventing the invasion of pathogenic bacteria. Most infections occur via the teat canal, so teat canal keratin (SKK) is of particular importance in non-specific defense of the gland. The SKK serves as a physical barrier, and bacteriostatic and/or bactericidal effects of SKK lipids and proteins against certain mastitis bacteria could be demonstrated. By increasing the concentrations of lactoferrin and lysozyme in milk a reduction of mastitis frequencies could be observed. However, those high concentrations in the proteins occur only during the dry period of the cow. An improvement of the mastitis situation would also appear possible by increasing phagocytosis. The numerous trials intended to reduce mastitis by improving specific protection showed no significant success. Therefore, the most successful and cheapest means to achieve udder health remains the strict and consistent hygiene of housing, animals and mammary glands.