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The present thesis assesses the stress responses relating to vaginal examinations in dairy cows. Therefore, two consecutive studies were conducted on two commercial dairy farms in Brandenburg, between 2010 and 2011. Although there is evidence that human contact is potentially stressful for cows, the impact of vaginal examinations on a cow’s stress level has not been evaluated. Therefore, we hypothesized that (1) cows show discomfort before and during vaginal examination with different behavioural reactions, (2) these reactions can be semi-quantitatively scored, (3) the heart rate increases during vaginal examination and decreases during the duration of the arched back and (4) the examination with a Metricheck® device is less invasive than the examination with the gloved hand. In the first study, the behaviour of 10 cows during vaginal examination was videotaped and analysed. In total, 15 different behavioural reactions were identified. Based on these observations, a numerical rating system was created. The avoidance reactivity score (ARS) includes six evasive reactions (standing still, tripping, stepping sideways, kicking, escape, leaning against the divider), which are scored on a 4-point scale. The ARS also includes signals of discomfort (arching the back, stretching the neck, vocalisation), scored with 1 point each. Evasive reactions are counted according to the strength of movement on an alternate scale. Signals of discomfort are counted with 1 point each on a cumulative scale. We also checked the reliability of the ARS by calculating the kappa (k) coefficients for inter- and intra-observer repeatability. Values near 0 can be interpreted as poor and values near 1 as almost perfect agreement between observers. For inter-observer agreement the coefficients were k = 0.61 and k = 0.71 between veterinarians and non-veterinarians, respectively. For intra-observer agreement, the coefficient was k = 0.84. Moreover, we compared two different examination methods, the Metricheck® device (MD) and the gloved hand (GH). The median ARS increased from 1 before (interquartile range, IQR: 1–2) to 3 during examination (IQR: 2–4) and cows in the group MD showed less avoidance reactions compared to cows in the group GH (P < 0.05). Parity, days in milk, vaginal discharge or repeated examinations did not influence the ARS.
In the second study, behaviour during cleaning the perivaginal region and 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 of the present thesis demonstrate that behavioural reactions can be assessed with a score. Substantial inter-observer and almost perfect intra-observer repeatability proved that the ARS can be applied easily in practice. The ARS – although imperfect – might be a useful tool in the field and in research to estimate a cow’s stress level. Moreover, the results show that vaginal examinations provoke stronger avoidance reactions in cows than mere restraining in the cubicle, so it can be considered a challenging and stressful situation. Cows cope with that challenge with various behavioural reactions and an increase in heart rate. In practice, routine vaginal examinations in dairy cows have not been considered as invasive examinations. However, vaginal examinations are an important mean to diagnose uterine diseases and cows benefit from early treatment. We do not suggest the application of any anaesthetic or analgesic 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. The examination with the Metricheck® device is less invasive than the manual examination.