Use of the liver activity index and other metabolic variables in the assessment of metabolic health in dairy herds.

The usefulness of the metabolic profile in dairy cows has been questioned because of poor standardization of procedures, high cost of analysis, and perceived inefficiency of the approach. Composite indices based on multiple variables, namely the Liver Activity Index and the Liver Functionality Index, which consider the pattern of changes of some negative acute-phase proteins in the first month of lactation, appear promising in the assessment of metabolic health status and the prediction of lactational and reproductive performance. The application of such indices depends on their reliability and on making them practical and economical regarding test cost and number of sampling points required.