1 Epidemiological Studies of Risk Factors for Bovine Mastitis

Nyman, A-K. 2007. Epidemiological studies of risk factors for bovine mastitis. Doctor’s dissertation. ISSN 1652-6880, ISBN 978-91-576-7379-4 This thesis describes some factors associated with mastitis in Swedish dairy herds, and with udder health of first-parity dairy cows. These factors were investigated in four observational studies including a total of 343 dairy herds and 3315 first-parity cows throughout Sweden. The herds were visited and the farmers interviewed about management, housing, feed, feeding, and milking. The quality of feed, as well as presence of udder pathogens at a case of clinical mastitis, was investigated in two of the studies. Blood samples were taken from first-parity cows in the period two weeks before calving to six weeks after calving for analysis of metabolites and immunological parameters in one of the studies. Udder health measurements used as outcomes in the studies were being a herd with a low or high incidence rate of veterinary treatments of clinical mastitis (CM), being a first-parity cow veterinary treated for CM in the period-7 to 30 days after calving, the withi