Screening of Dairy Cows for Ketosis by Use of Infrared Spectroscopy and Multivariate Calibration

A fast and inexpensive method of screening ketosis in cows is presented. This method is based on the determination of acetone in bovine milk by using Fourier transform infrared spectroscopy combined with multivariate calibration. Only samples with a naturally increased acetone content could be used in the calibration step; samples containing added acetone did not produce an acceptable calibration equation. On test samples ranging from 0.0 to 2.8 mM acetone, an R2 of 0.81 and an accuracy (root mean square error of prediction) of 0.27 mM were obtained. This accuracy was sufficient to classify the cows into two groups: healthy and possibly ketotic. No false negatives were determined for the present data set.