The stress level is considered as one important aspect of dairy cow welfare. Beside aspects of
housing, management and social herd stressors, stress might also be related to the
human-animal relationship (HAR). An established and non-invasive physiological method
to assess medium-term stress is the measurement of fecal cortisol metabolites (FCM),
reflecting the adrenocortical activity over several hours with a delay of 8-10
hours due to gut passage time. For the
assessment of the HAR, behavioural tests recording the cows´ responses towards
humans can be used. Beside quantitative methods, e.g. recording the cows´
avoidance distances towards humans, also the qualitative behaviour assessment
(QBA) assessing the cows´ body language have been shown to be reliably
applicable. Thereby, QBA might reflect the cows´ responses in a more
differentiated way than quantitative measures. Using data from 316 dairy cows
on 25 German organic dairy farms regarding QBA during a standardised tactile human-animal
interaction and FCM recorded on the same day, but with time differences varying
between 0-10 h (during winter 2015/16 and 2016/17), we asked whether the cows’ qualitatively
assessed behaviour towards humans is related to their general medium-term stress
level.For QBA we used a fixed list of 20
descriptors, which had specifically been developed for this purpose. A
principal component analysis (PCA) resulted in two components: PC1 explained
67% of variance and appeared to reflect ‘positive’ (pos) and ‘negative’ (neg) valence
(characteristic descriptors pos: e.g. trustful, relaxed; neg: e.g. fearful,
distressed). PC2 explained 7% of variance and appeared to reflect the level of activation
(‘high’ activation: e.g. contact-seeking, aggressive; ‘low’ activation: e.g. patient,
insecure). Dividing the sample into four groups (pos_low, pos_high, neg_low,
neg_high) using the medians of PC1 and PC2 as cut-points, we compared FCM levels
(11,17 dioxoandrostanes, enzyme immunoassay method) by Kruskal-Wallis and
post-hoc Wilcoxon rank-sum tests. Groups of cows
classified by QBA differed regarding FCM (p=0.010, Kruskal-Wallis test). Cows reacting
pos_high during the human-animal interaction (n=65), pos_low (n=93) and neg_low
(n=99) had similar FCM levels (medians of 12.0, 10.3 and 10.4; 25-75% quartiles:
6.8-22.8, 4.9-22.0, and 4.2-18.5 ng/g FCM; p=0.225-0.699, Wilcoxon tests). In
contrast, neg_high cows had significantly lower FCM levels (6.5 ng/g, 3.7-12.5,
n=59) than all other groups (p=0.001-0.029). Neg_high cows presumably had
higher fear levels towards humans than pos cows, and expressed this more
actively than neg_low cows. Unexpectedly, however, the neg reaction was not
related to a generally higher stress level. In this context, it must be taken
into account that FCM medians and variation in the investigated sample were
generally on a low level. Furthermore, other factors such as social rank or health
status might have affected results more profoundly, deserving a more complex analysis including
individual factors as a next step.