Evaluation of aspartate transaminase activity and β-hydroxybutyrate concentration in blood as tests for prediction of left displaced abomasum in dairy cows

Abstract

SUMMARY Objectives To evaluate aspartate transaminase (AST) activity and β-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 at 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 PP days, which was 5 to 18 days prior to LDA diagnosis, were matched to 3 controls per case by herd and calving date. Data were available from a large field study. Procedure Odds ratio, sensitivity, specificity, and likelihood ratio were determined for various AST and BHB cutoff values. Results AST, using cutoff values between 100 and 180 U/L, and BHB, using cutoff values between 1,000 and 1,600 μmol/L, were significantly associated with subsequent LDA diagnosis. When cutoff values were increased, odds ratio and likelihood ratio increased; however, sensitivity decreased and specificity increased. Conclusion and Clinical Relevance AST activity and BHB concentration in blood obtained during the first or second PP week might be useful as predictors of subsequent LDA diagnosis. (Am J Vet Res 1997;58:1216–1220)