Comparative assessment of the stress level of dairy cows from stimuli encountered in everyday life

Failure to carry out common practices in stress research has led to a lack of comparability. The aim of this study was to analyse, whether, and to what extent everyday stimuli can be considered stressful. The stimuli tested in this study were artificial insemination (AI), embryo transfer (ET), natural breeding (NB), morning milking (MM), evening milking (EM), veterinary examination (VE), ultrasound examination (US) and hoof trimming (HT). The stimuli were compared by examin-ing their impact on the hypothalamic–pituitary–adrenal axis through serum-cortisol analysis. The test herd, comprising 24 multiparous Holstein Friesian cows, was divided randomly every test day into treatment (Tr) and control groups (Co). Basal blood samples were taken 40 min (B1) and 20 min (B2) prior to stimulus application, im-mediately following the stimulus (S) as well as 20 min (R1) and 40 min (R2) post-stimulus. Comparison of serum-cortisol in Tr groups shows a significant difference between NB to AI (p = .011); ET (p = .006), EM (p = .009), VE (p = .030) and US (p = .010). There is no signifi-cant difference between Co groups (p > .05). Cortisol levels within Co groups vary only slightly over time. The stimuli ET (p < .001), MM (p < .001), ME (p = .000), HT (p < .001) and NB (p < .001) show signifi-cant increases in cortisol after stimulus application, the levels fail to decrease significantly in the stimuli HT and NB. The presented data can be used to create recommendations for improving the welfare and productivity of dairy cows and influencing the development of new animal husbandry techniques.