Many research publications and resources are available to help calf raisers use refractometers. This bulletin summarizes current recommendations and references. The Brix refractometer measures sucrose concentrations in liquids like wine and fruit juice. When used to measure non-sucrose containing liquids, the Brix% approximates the total solids percentage. Questions that can be answered with a refractometer include: • What is the colostrum immunoglobulin content? • What is the passive antibody transfer success rate? • What is the total solids content of the whole milk or milk replacer?