Abstract: In order to investigate relationships of adult horses to humans, we developed a simple evaluation test and scores based on observations. The first reactions of 224 adult horses to the presence of an experimenter were observed and scored. All these horses belonged to the same riding school, had the same general housing conditions and were all geldings. The evaluation was based on the horse's posture. Individual differences that could be related to some extent to the breed but also to human factors emerged clearly. French saddlebreds showed more often friendly behaviour than Angloarabs, whereas thoroughbreds were more indifferent. Clear variations occurred between groups of horses that depended on different caretakers. In this school, one caretaker is responsible for the whole daily management of a group of horses and is probably a very important factor in their well-being. The effects of this daily relation to a human seemed to be involved in the reactions to a strange person. Further studies are required to investigate what, in practice, may be determinant.

Abstract: Social recognition among familiar unrelated lambs was assessed in a series of tests. Lambs and their mothers were housed together in small groups for 1 week (Original groups; O) then reorganized into new groupings (Recent-groups; R) for the remainder of the experiment. During test series 1, lambs that were paired with a familiar O-group partner, from which they had been separated for 5 days, emitted fewer distress bleats than did those tested with an unfamiliar partner. This same effect was not evident when the test was repeated several hours later, indicating that the animals had become habituated to the testing procedures. Two days later, when given the choice between an O- versus a R-partner (test series 2), lambs did not display a preference for either of the stimulus lambs. However, in an additional two-choice test (test series 3) the subject lambs responded discriminatively to a recent familiar partner that was simultaneously present with an unfamiliar lamb. Overall, the results suggest that lambs are capable of developing discriminative relationships with age-mates from different sub-groups, and that such social discrimination persists over a separation period lasting at least several days. It is not clear whether lambs recognize several individual conspecifics per se or discriminate between members of higher order social categories (e.g. familiar versus unfamiliar individuals). Proximal and distal social discrimination may be mediated by different combinations of sensory modalities.

Abstract: Performance of horses, whether in sports or in leisure, depends on both physical abilities as well as temperament. The aim of the present work was to measure individual variation and consistency of behavioural variables, related to temperament, in young horses of the same breed and age, and reared under controlled housing conditions and management. A total of 41 Dutch Warmblood horses were tested at 9, 10, 21 and 22 months of age in two behavioural tests, i.e. the novel object test and the handling test. In the novel object test horses were confronted with an open umbrella that was lowered from the ceiling. In the handling test horses were led by a human to cross a bridge. Per test, behavioural variables in the following behavioural classes were observed: locomotor activity, latency times, postural expressions and vocalisations. Within years, all behavioural variables in the handling test, and all but two in the novel object test were positively correlated (0.36<Rs<0.81, P<0.05). For both tests, at 9, 10, 21 and 22 months of age, a principal component analysis (PCA) was carried out to examine whether there were indications for underlying components of these individual behavioural variables that could possibly serve as measures for temperamental traits. The first component in the novel object test could be regarded as `flightiness' and the second as `sensitiveness'. In the handling test, the first component was suggested to relate to `patience', the second component to `willingness to perform'. The temperamental trait `flightiness' (novel object test) as well as the temperamental trait `patience' (handling test) were positively correlated within both years (0.36<Rs<0.65, P<0.05). For the traits `sensitiveness' (novel object test) and `willingness to perform' (handling test) a positive correlation was only found within the first year (0.44<Rs<0.57, P<0.01). A few individual behavioural variables showed consistency over years. Additionally, just one out of four temperamental traits, namely `flightiness', proved to be consistent over years (Rs=0.49, P<0.01). The temperamental trait `patience' showed a trend between years (Rs=0.31, 0.05<P<0.1). It is concluded that the behavioural tests employed in the present study can be used to reliably identify individual behavioural variables and temperamental traits in young horses. Long-term consistency, i.e. between subsequent years, could not be demonstrated convincingly. Nevertheless, future work may indicate that employing the same approach and considering an even longer time period or different phases of the horse's life, long-term consistency does exist.

Abstract: Seven experiments were conducted on four miniature pigs to determine: (1) whether the pigs can discriminate between people wearing the same coloured clothing; (2) what cues they rely on if they could discriminate. For 2 weeks before the experiments began, the pigs were conditioned in a Y-maze to receive raisins from the rewarder wearing dark blue coveralls. They were then given the opportunity to choose the rewarder or non-rewarder in these experiments. Each session consisted of 20 trials. Successful discrimination was that the pig chose the rewarder at least 15 times in 20 trials (P<0.05: by χ2-test). In Experiment 1, both rewarder and non-rewarder wore dark blue coveralls. By 20 sessions, all pigs successfully identified the rewarder. In Experiment 2: (1) both wore coveralls of the same new colours or (2) one of them wore coveralls of new colours. They significantly preferred the rewarder even though the rewarder and/or non-rewarder wore coveralls of new colours. In Experiment 3, both wore dark blue coveralls but olfactory cues were obscured and auditory cues were not given. The pigs were able to identify the rewarder successfully irrespective of changing auditory and olfactory cues. In Experiment 4, both wore dark blue coveralls but covered part of their face and body in different ways. The correct response rate decreased when a part of the face and the whole body of the rewarder and non-rewarder were covered. In Experiment 5, both wore dark blue coveralls and changed their apparent body size by shifting sitting position. The correct response rate increased as the difference in body size between the experimenters increased. In Experiment 6, the distance between the experimenters and the pig was increased by 30 cm increments. The correct response rate of each pig decreased as the experimenters receded from the pig, but performance varied among the pigs. In Experiment 7, the light intensity of the experimental room was reduced from 550 to 80 lx and then to 20 lx. The correct response rate of each pig decreased with the reduction in light intensity, but all the pigs discriminated the rewarder from the non-rewarder significantly even at 20 lx. In conclusion, the pigs were able to discriminate between people wearing coveralls of the same colour after sufficient reinforcement. These results indicate that pigs are capable of using visual cues to discriminate between people.

Abstract: We examined the effects of the presence of an unfamiliar, a gentle or an aversive handler during milking on behaviour and milk yield, and whether cows can learn to approach or avoid a handler by observing the neighbouring cow?s responses. In Experiment 1, Danish Friesian cows (n=16) were treated gently (offering hay and concentrates) by one handler and aversively (hit every 15s on the head with the hand) by another handler for six periods of 2min each. The two handlers wore different coloured overalls, and each cow received either gentle or aversive treatment in the first week and the other treatment the following week. All cows kept a longer distance to the aversive than to the gentle handler in a 1min test after treatment. Milk yield and residual milk did not differ when the aversive or the gentle handler was standing in front of the cow during milking, although the cows moved their legs and tail less when the aversive handler was present. When an unfamiliar person was standing in front of the cows during milking, behaviour and milk yield did not differ from control milkings. Cows and heifers (n=10) that had observed their neighbours receiving gentle treatment by one handler and aversive treatment from another handler did not differ in the distance they kept from these two handlers. In Experiment 2, cows (n=15) that had observed the neighbours receiving a gentle treatment (eight times for 2min) kept a shorter distance to that handler after treatment of their neighbours, and the distance they kept was correlated with the distance kept by the neighbouring cows. This suggests that responses of observer cows may be affected by the responses of the cows being treated. The cows rapidly learned to avoid an aversive handler, but although the cows showed clear avoidance response to the aversive handler there was no effect on milk yield when the aversive handler was present at milking.