Colostrum samples of first, second, and third milking were collected from 72 cows. Immunoglobulins were determined by colostrometer, Brix refractometer, online Afilab spectrometer, and ELISA. Correlation of immunoglobulin G level measured by ELISA and colostrometer was 0.79, for Brix 0.76, and for Afilab 0.70. Assuming a dichotomic cutoff at 50 mg mL^-1, sensitivity was 88.2% and specificity was 87.9%. Afilab can provide measures of colostrum quality in real time and all the herd data are stored on the computer automatically, therefore it could be used for further analyses for management decisions and genetic evaluation.