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Ettenhausen, Switzerland

Gygax L.,Institute of Livestock Science ILS | Vogeli S.,Institute of Livestock Science ILS | Vogeli S.,University of Zurich
Applied Animal Behaviour Science | Year: 2016

There is an increasing interest in affective states in applied animal behaviour science, because these states are thought to reflect welfare from the perspective of the animals. Also, it can be expected that individuals differ in how they consistently react to emotional challenges. Recently, we conducted three experiments in which the same sheep were repeatedly confronted with either physical, social or thermal stimuli that presumably varied in their valence. These sheep had been housed in either unpredictable, stimulus-poor or predictable, stimulus-rich housing conditions in order to manipulate their long-term mood. When the sheep were exposed to the stimuli, we measured general activity, ear movements, ear postures and frontal cortical haemodynamic changes as indicator variables for their emotional reaction. In the meta-analysis presented here, we searched for effects of the presumed valence and mood state on the indicator variables. Furthermore, we investigated the unexplained between- versus within-subject variability as an indicator of personality. Deoxy- [HHb] and oxy-haemoglobin concentrations [O2Hb] as well as general activity showed weak linear relationships with presumed valence. Sheep from the unpredictable, stimulus-poor housing conditions were generally more active and showed more ear movements, higher absolute [HHb], more transverse ears and less left-forward ears than sheep from the predictable, stimulus-rich housing conditions. However, these differences were small. The ratio of between- to within-individual variability was very low indicating little consistency in individual reactions. In conclusion, we found only weak evidence that presumed valence had a consistent effect on the indicator variables for emotional reactions in a given sheep, and these reactions were not modulated by presumed mood. Also, there was little indication that the sheep reacted in a way reflecting an individualised personality. © 2015 Elsevier B.V. Source

Vogeli S.,Institute of Livestock Science ILS | Vogeli S.,University of Zurich | Wolf M.,University of Zurich | Wechsler B.,Institute of Livestock Science ILS | Gygax L.,Institute of Livestock Science ILS
Behavioural Brain Research | Year: 2015

Mood, as a long-term affective state, is thought to modulate short-term emotional reactions in animals, but the details of this interplay have hardly been investigated experimentally. Apart from a basic interest in this affective system, mood is likely to have an important impact on animal welfare, as bad mood may taint all emotional experience. In the present study about mood - emotion interaction, 29 sheep were kept under predictable, stimulus-rich or unpredictable, stimulus-poor housing conditions, to induce different mood states. In an experiment, the animals were confronted with video sequences of social interactions of conspecifics showing agonistic interactions, ruminating or tolerantly co-feeding as stimuli of different valences. Emotional reactions were assessed by measuring frontal brain activity using functional near-infrared spectroscopy and by recording behavioral reactions. Attentiveness of the sheep decreased from videos showing agonistic interactions to ruminating sheep to those displaying co-feeding sheep. Seeing agonistic interactions was also associated with a deactivation of the frontal cortex, specifically in animals living under predictable, stimulus-rich housing conditions. These sheep generally showed less attentiveness and locomotor activity and they had their ears in a forward position less often and in a backward position more often than the sheep from the unpredictable, stimulus-poor conditions. Housing conditions influenced how the sheep behaved, which can either be thought to be mediated by mood or by the animals' previous experience with stimulus-richness in their housing conditions. Frontal cortical activity may not depend on valence only, but also on the perceptual channel through which the stimuli were perceived. © 2015 Elsevier B.V. Source

Zwicker B.,Institute of Livestock Science ILS | Weber R.,Institute of Livestock Science ILS | Wechsler B.,Institute of Livestock Science ILS | Gygax L.,Institute of Livestock Science ILS
Applied Animal Behaviour Science | Year: 2015

Pigs are sociable animals with a strong motivation to explore and forage, and it has been stated that they have a strong motivation to do so synchronously. We examined the synchrony of exploration in groups of finishing pigs when enrichment materials were offered. We used a novel measure of relative synchrony for which no artificial threshold for synchrony was needed and which takes into account detailed individual data for calculating expected random synchrony.One hundred and ninety-two growing pigs were housed in groups of six animals in pens with partly-slatted floors. In two experiments, four enrichment materials each were tested one at a time and, for a given group of pigs, the material was changed every three weeks. Half of the groups were fed twice daily in a restricted manner, the other half ad libitum. Exploratory behaviour directed to the material and to the pen was scored. Relative synchrony was calculated as the observed divided by the expected synchrony for two, three, four, five and six pigs behaving synchronously. The expected synchrony was calculated using the daily individual data of each pig. Data were analysed using linear mixed-effects models. Results showed that relative synchrony for combined exploration (exploring material or pen) monotonously increased with increasing number of animals behaving synchronously in both experiments and reached above-chance values of synchrony at three to four animals. A similar pattern was found for exploring cut straw as litter with maize and cut straw as litter: synchrony increased with the number of synchronously exploring pigs to above-chance values of synchrony for four and more pigs. Relative synchrony for exploring a straw block decreased with increasing number of animals exploring synchronously with all values of synchrony below chance level. Relative synchrony increased for all the other materials (straw rack, chopped straw, chopped Miscanthus giganteus, pellet dispenser, bark compost) for up to three to four animals exploring synchronously. For higher numbers of animals, relative synchrony decreased. Above-chance values were reached at three to four animals.In conclusion, finishing pigs seem to have a strong motivation to explore synchronously in groups of up to six animals. If enrichment material is available and accessible to all animals, they will direct their behaviour to that material, whereas they redirect exploration behaviour to pen structures to achieve a high level of synchrony if access to enrichment material is restricted. The method of calculating relative synchrony based on individual observations and for any given number of animals in a group proved useful. © 2015 Elsevier B.V. Source

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