EVALUATION OF BOVINE TEAT CONDITION IN COMMERCIAL DAIRY HERDS: 4. RELATIONSHIP BETWEEN TEAT-END CALLOSITY OR HYPERKERATOSIS AND MASTITIS

The teat canal is the primary physical and chemical barrier to invasion of mastitis pathogens into the udder (Hamann, 1987). Between milkings, the smooth muscles surrounding the teat duct should be contracted and the teat canal tightly closed to impede bacterial passage from the teat orifice into the interior of the gland (Nickerson, 1994). A teat-end in good condition is an important resistance factor to bacterial colonization of the mammary gland (Michel et al., 1974). Changes in teat tissue by milking, teat canal integrity, and teat tissue pliability may favour penetration of bacteria into the udder (O’Shea et al., 1987). Veterinarians and others require a simple and reliable method for evaluating teat health in dairy herds. A complete protocol for systematic evaluation of teat condition in commercial herds is proposed by a group of international experts on teat condition (Mein et al., 2001). The new protocol includes an assessment of teat-end callosity (TEC). The evaluation of teat-end callosity is based on a research classification system. This paper covers information about the relationship between teat-end callosity and udder health