The experiment was conducted to investigate how cows in a loose housing system reacted to the automated blood sampling system. Concentrations of cortisol both in the morning (mean 4.24 ± 0.53 ng/ml) and around midday (4.93 ± 0.62 ng/ml) were within the normal range of baseline levels (Fig. 5). During these two periods the cows were lying, eating, grooming, and sometimes milked in the robotic milking machine or brushed by automatic mechanical brushes. In the morning the cortisol concentration was higher in sample 1 compared to samples 4–14 (P < 0.05) and in sample 2 compared to samples 5, 8, 9 and 13 (P < 0.05). However, around midday no differences were found in the samples (P = 0.78). High cortisol values in the first two morning samples could indicate that the animal was affected by the handling and the mounting of the IceSampler. An alternative explanation could be that the animal was affected by morning routines in the stall, e.g. feeding or cleaning. Further experiments are needed to clarify this.