Determination of D-lactate in calf serum samples – an automated enzymatic assay

Abstract

Since recent research has shown that D-lactataemia is obviously not an unusual problem in calves, determination of this metabolite may have considerable clinical significance. In analogy to the routinely used L-lactate assay, a stereospecific enzymatic assay of D-lactate was automated on a Hitachi Automatic Analyzer 911. As the method described does not require deproteinisation, and amounts of reagents are small, the determination is inexpensive and not labour-intensive. The method proved to be both accurate and reliable, with a limit of linearity of 16 mmol/l. A reference range was established using serum samples from 150 clinically healthy Simmental calves of both sexes, up to 3 weeks old, from 48 dairy farms in southern Germany. An upper limit of the reference range (95th percentile) of 3.96 mmol/l was found.