Gentle human interactions and positive emotions in cattle

The experience of positive emotions, e.g. joy, is essential for farm animal welfare. It may also have an economic impact by enhancing health via physiological responses. As the focus of research on animal welfare has traditionally been the avoidance of negative emotions, studies of positive emotions in farm animals are rare, especially regarding the role of humans as a potential source. Gentle interactions (stroking and talking in a gentle voice) are considered to induce positive emotions in cattle but studies are contradictory and some animals apparently do not perceive the interactions as positive. It is necessary to find out how to induce positive emotions most effectively and to further investigate their physiological effects. First, we will test whether cattle prefer being stroked in a flexible, reactive way to standardized stroking on the ventral side of the neck. We believe that it may be important how much control an animal has over the situation for it to perceive the gentle interactions with humans as positive. We will conduct two experiments to investigate different aspects of control during gentle interactions, using behavioural observation and measurement of heart rate to make conclusions about the animals` emotional state. We will compare the reactions of cattle to gentle interactions during restraint and in a situation where they are free to move and avoid the experimenter; and we will investigate whether it is more effective to habituate cattle to gentle interactions with humans while they are restrained or free- moving. We also believe that the perception of gentle interactions with humans is influenced by the sensory channels targeted in the interaction. We will compare the influences of stroking and of talking in a gentle voice in a stressful situation after previous habituation of the animals to the interactions. An animal will be isolated in a novel environment, causing behavioural and physiological stress responses; a human will then join the animal and we will measure whether stroking or talking to the animal or the combination of both leads to a stronger reduction of stress responses. Finally, we suggest that gentle interactions with humans, if perceived as positive, have physiological effects that can promote animal health. We will thus investigate whether gentle interactions affect different physiological parameters linked to relaxation, stress and the immune system. Our research will yield valuable information on the relationships between emotions, behaviour and physiology. The results may aid in the improvement of the welfare of cattle and potentially other farmed species.

The experience of positive emotions is essential for good well-being of farm animals. It may also have an economic impact by enhancing health and production via physiological responses. Gentle interactions (stroking and talking in a gentle voice) usually induce positive emotions in cattle but not under all circumstances. The overarching aim of the project was thus to elucidate which characteristics of gentle tactile and vocal interactions with humans improve or impair their positive perception by cattle and how they affect cattle physiology. First, we compared the reactions of young cattle to stroking by a familiar person, either while the person was talking in a gentle voice directly to them or while a recording of the human talking was played, which might be relevant for standardization in future experiments. The behaviour did not differ substantially between the two conditions, but heart rate characteristics indicated a stronger relaxation effect after live talking. In addition, the variability in the data was not reduced consistently. Thus, using a playback stimulus is not advantageous in terms of standardization and, moreover, might be less effective in eliciting a positive perception of the interactions in the animal than talking directly to it. We also compared different stroking styles: stroking the ventral neck, which has previously been identified as a generally preferred area, and stroking the entire head-neck area while reacting to the perceived momentary preference of the animal. The behaviour indicated that both ways of stroking were perceived as positive, but there were very few differences. This finding also reflects the methodological challenges of discriminating between different intensities of positive emotions. We found effects of restraint during gentle vocal and tactile interactions with humans: If heifers with a good relationship with humans were free to move, they showed more behavioural signs of enjoyment than when they were stroked while restrained. Furthermore, their heart rate tended to decrease during free stroking. This is in line with the results of our experiment with cows that were fearful of humans: We found a small improvement of the animals' relationship towards humans if they experienced gentle interactions during restraint, whereas the improvement was more distinct in cows that experienced the interactions while free to move. Finally, we did not find changes in salivary oxytocin, immunoglobulin A (IgA) or cortisol concentrations in heifers after gentle interactions with humans, although the heart rate decreased over the course of the test in animals experiencing gentle interactions, in contrast to the two controls (presence and absence of person). Oxytocin and IgA have come into the focus of animal welfare research especially as potential indicators of positive affective states, but these results speak against their usefulness in this context.