EVALUATION OF ASPARTATE-TRANSAMINASE ACTIVITY AND BETA-HYDROXYBUTYRATE CONCENTRATION IN BLOOD AS TESTS FOR PREDICTION OF LEFT DISPLACED ABOMASUM IN DAIRY-COWS

Objectives-To evaluate aspartate transaminase (AST) activity and beta- hydroxybutyrate (BHB) concentration in blood obtained during the first or second postpartum (PP) week as tests for prediction of subsequent left displaced abomasum (LDA) diagnosis in dairy cows. Animals-36 cows with LDA tested al a mean 3 PP days, which was 7 to 22 days prior to LDA diagnosis (25, 75% quantiles), and 28 cows with LDA tested at 10 P P days, which was 5 to 18 days prior to LDA diagnosis, were matched to 3 controls per case by herd and calving dale. Data were available fro m a large field study. Procedure-Odds ratio, sensitivity, specificity, and likelihood ratio were determined for various AST and BHB cutoff v alues. Results-AST, using cutoff values between 100 and 180 U/L, and B HB, using cutoff values between 1,000 and 1,600 mu mol/L, were signifi cantly associated with subsequent LDA diagnosis. When cutoff values we re increased, odds ratio and likelihood ratio increased; however, sens itivity decreased and specificity increased. Conclusion and Clinical R elevance-AST activity and BHB concentration in brood obtained during t he first or second PP week might be useful as predictors of subsequent LDA diagnosis.