Behavioural and physiological assessment of stress reactions during vaginal examination in dairy cows

The objective of this study was to determine the origin of an arched back in cows during vaginal examination. Moreover, we tested whether the duration of an arched back and avoidance reactions during vaginal examination can be decreased by epidural anaesthesia or analgesic treatment.

Behaviour during cleaning of the perivaginal region and during vaginal examination was scored using the avoidance reactivity score (ARS). Heart rate (HR) was recorded in 10 dairy cows considering four experimental phases, i.e. baseline, cleaning the perivaginal region, vaginal examination and post-examination. Each cow was examined three times and received no treatment (CON), an epidural anaesthesia (EPID) or an analgesic treatment (NSAID). The duration of an arched back during and post-examination was measured.

The expression of the arched back was shortest in cows of group EPID and longest in cows of group CON. Avoidance reactions did not differ between the cleaning phase and vaginal examination in cows of group EPID. Cows of group CON showed the strongest avoidance reactions during examination, whereas cows of group EPID showed least avoidance reactions. Mean HR increased during cleaning and vaginal examination and decreased post-examination. Mean HR during vaginal examination did not differ between treatment groups.

The results show that cows express discomfort during vaginal examination with an increase in avoidance reactions and HR. Although epidural anaesthesia could reduce sensitivity in the perivaginal region, cows still felt the urge to empty the vagina from the examiner's hand and, thus, were arching their back.

In practice, routine vaginal examinations in dairy cows have not been considered as invasive examina- tions. Our results show that vaginal examinations indeed do cause discomfort. We do not suggest the application of any anaesthetic treatment as appropriate before routine vaginal examinations. Nonetheless, the examiner should be aware of the stress potential of vaginal examinations and conduct such examinations most carefully.