CASE STUDY: Using Urine pH as a Predictor for Ketosis in Transition Dairy Cows 1 1 Approved by the director of the Louisiana Agricultural Experiment Station as Publication No. 05-24-0248

An experiment was conducted to determine whether urine pH could be used to predict the incidence of ketosis in transition dairy cows. Urine was collected three times weekly from 41 Holstein cows from approximately 21 d prepartum until 21 d postpartum. Concentrations of acetoacetate and the pH of the urine were measured immediately; then, the urine was stored frozen until later analysis for concentrations of [beta]-hydroxybutyrate (BHBA ). Correlations between urine pH and concentrations of acetoacetate and BHBA were -0.50 and -0.65, respectively. Stepwise regression was used to determine variables that were related to concentrations of ketones in the urine. Urine pH was a significant (P