ABSTRACT
Mastitis is inflammation of the udder due either to infection or physiological change; most mastitis is associated with microbial infection. The course of infection varies; often the early stage of infection is subclinical, that is, the changes in milk composition and inflammation are so slight that they are not detected by the dairy farmer. The losses in milk yield and lowered milk compositional quality of mastitic quarters has been extensively reviewed. Any control system will be concerned with the rate of new infection and the elimination of existing infection. In practice lower cure rates may be expected since many of the infections may be of longer duration than those treated in the reported experiment and E. coli may be treated with inappropriate antibiotics. Culling has the greatest beneficial effect in herds with very low levels of mastitis. The type of bedding material used affects dry-period new infections and the incidence of new infection between calving and going to grass.
