Detect sub-clinical ketosis in transition dairy cows. PortaBHB is an easy-to-use, on-farm, dipstick milk test, not a urine test, which detects BHB (beta-hydroxybutyrate). Results correlate well with the serumketone test. High levels of BHB are a sign of ketosis, a metabolic disorder that indicates a negative energy balance. No additional equipment is needed.