This thesis is an investigation of the interactions of insulin resistance (IR), metabolic markers, neutrophil function, and reproductive health in peripartum dairy cows, including the evaluation of a hand-held glucometer for diagnosis of IR. The neutrophil functions of interest were oxidative burst and phagocytosis capacity, and reproductive diseases were endometritis and cervicitis. A total of 81 Holstein cows were enrolled 3 wk prior to expected calving date from November 2010 until October 2011, and were followed until 5 wk postpartum. Known markers of IR, neutrophil function, and disease were monitored through this period. The hand-held glucometer was identified as a useful alternative to laboratory measurements of glucose. Markers of IR influenced phagocytosis capacity and reproductive disease. High haptoglobin concentrations were associated with increased risk of reproductive disease and diminished oxidative burst function. Metabolically related inhibition of neutrophil function may be important in development of reproductive disease. / National Sciences and Engineering Research Council of Canada, Ontario Graduate Scholarship Program