Abstract: A modified spontaneous object recognition test was used to examine object recognition memory in the domestic pig. This test uses preference for a novel object over a previously encountered sample object as indicating recognition of the sample object, and no preference as indicating no recognition. Two factors hypothesized to affect object recognition are duration of exposure to the sample stimulus and delay interval before re-exposure. Both of these factors could be manipulated in a rotational object enrichment program for pigs. Reducing exposure time and increasing the delay interval before re-exposure should decrease object recognition and prolong novelty-induced object exploration. We exposed 5-week-old pigs to different sample objects in their home pens for 10 min and 2 days, respectively. We tested for object recognition memory at various delay intervals after initial exposure by placing littermate pairs in a test pen for 10 min and recording snout contact with a sample object and a completely novel object. At a 1-h delay, half the pairs were tested with the 2-day sample object; the other half received the 10-min sample object. At a 3-h delay, pairs were tested with the opposite sample object. Pairs were also tested with the 2-day sample at a 5-day delay and the 10-min sample at a 6-day delay. We predicted that pigs would show a preference for the novel versus the 2-day sample object at all three delays, but would only prefer the novel object over the 10-min sample object at the 1-h and 3-h delays. Pigs did not show novelty preference in the presence of the 10-min sample object at any delay. Novelty preference in the presence of the 2-day sample object occurred at the 3-h (P < 0.05) and 5-day delays (P < 0.001), but not the 1-h delay. The lack of novelty preference when pigs were tested with the 10-min sample object may have been due to failure to habituate to the sample object. Testing in a different location from the initial sample object exposure and retroactive interference from exposure to the 10-min sample object may have contributed to a temporary lack of novelty preference when pigs were tested with the 2-day sample object at the 1-h delay. The finding that pigs retained a memory for the 2-day sample object for at least 5 days suggests that restricting object exposure to less than 2 days may help to preserve the exploratory value of objects rotated among pens.

Abstract: The present paper focuses on six main issues. First, we briefly explain why an increased understanding of the human-animal relationship (HAR) is an essential component of any strategy intended to improve the welfare of farmed animals and their stockpersons. Second, we list the main internal and external factors that can influence the nature of the relationship and the interactions between human beings and farm animals. Third, we argue that the numerous tests that have been used to assess the HAR fall into three main categories (stationary human, moving human, handling/restraint), according to the degree of human involvement. Fourth, the requirements that any test of HAR must fulfil before it can be considered effective, and the ways in which the tests can be validated are discussed. Fifth, the various types of test procedures that have been used to assess the HAR in a range of farmed species are reviewed and critically discussed. Finally, some research perspectives that merit further attention are shown. The present review embraces a range of farmed animals. Our primary reasons for including a particular species were: whether or not general interest has been expressed in its welfare and its relationship with humans, whether relevant literature was available, and whether it is farmed in at least some European countries. Therefore, we include large and small ruminants (cattle, sheep, goats), pigs, poultry (chickens), fur animals (foxes, mink) and horses. Although horses are primarily used for sport, leisure or therapy they are farmed as draught, food or breeding animals in many countries. Literature on the HAR in other species was relatively scarce so they receive no further mention here.

Abstract: In modern intensive husbandry systems there is an increasing tendency for animals to interact with technical equipment. If the animal-technology interface is well-designed this may improve animal welfare by offering challenges for cognitive adaptation. Here a system and its application is presented that acoustically calls individual pigs out of a group (n = 8) to a feeding station. In three different learning phases, the computer-controlled “call-feeding-station” (CFS) trained the animals to recognize a specific acoustic signal as a summons for food, using a combination of classical and operant conditioning techniques. The experimental group's stall contained four CFSs, at each of which one animal at a time was able to feed. When an animal had learned to discriminate and recognize its individual acoustic signal it had to localize the particular CFS that was calling and to enter inside it. Then, it received a portion of feed, the amount of which was adapted to the respective age of the animals. Each animal was called at several, unpredictable times each day and the computer programme ensured that the total feed supply was sufficient for each animal. In the last phase of the experiment the animals, in addition, had to press a button with an increasing fixed ratio for the delivery of feed. It was demonstrated that the pigs were able to adapt quickly to the CFSs. Although they were challenged over 12 h daily by requirements of attention, sensory localization and motor efforts to gain comparatively low amounts of feed, they performed well and reached fairly constant success rates between 90 and 95% and short delays between 14 and 16 s between a summons and the food release in the last phase of the experiment. The weight gain during the experiment was the same as in a conventionally fed control group (n = 8). We therefore conclude that CFSs present a positive challenge to the animals with no negative effects on performance but with a potentially beneficial role for welfare and against boredom. The system is also a suitable experimental platform for research on the effects of successful adaptation by rewarded cognitive processes in pigs.

Abstract: The human-animal relationship is an important factor when considering animal welfare at herd level. In the present study, two behavioural tests for the on-farm assessment of the human-animal relationship at herd level of dairy cows housed in loose housing cubicle systems were evaluated with respect to inter-observer reliability, test-retest reliability, effect of familiarity of test person as well as inter-correlation of the two tests. In a voluntary animal approach (VAA) test, the number of cows and the latencies to approach and touch a stationary test person was measured. In an avoidance (AV) test, the cows' avoidance reactions to an approaching test person were categorised. A first study was carried out in 12 commercial Danish and Austrian dairy farms. On each farm, both behaviour tests were carried out on the same day and repeated within 4-5 days. For each test, cows were tested by both an unfamiliar and a familiar test person (the stock-person) and two observers simultaneously registered the animals' test responses. The inter-observer reliability of both behavioural tests was found to be high (VAA: 2.5-m approach r=0.98 (P<0.001) and touch r=0.97 (P<0.001); AV: Kappa coefficientweighted=0.886 (prevalence index for flight distance>=2 m is 0.636)). The cows at herd level showed shortest latency for touching an unfamiliar test person on the first test day (P=0.006). Further, the AV test had a high test-retest reliability (Kappa coefficientweighted=0.503 (prevalence index for flight distance>=2 m is -0.660)) and results indicated no effect of familiarity of test person (Kappa coefficientweighted=0.463 (prevalence index for flight distance>=2 m is -0.677)). In a second study, the correlation between the two behavioural tests (similar measures) was evaluated. On each of 10 commercial Danish dairy farms with loose housing cubicle systems at four repeated sessions, both behaviour tests were carried out on the same day. For each test cows were tested by the stock-person. The VAA and AV tests at herd level were highly correlated (rs=-0.84; P=0.002). The results suggest that the AV test is valid and applicable for on-farm assessment of the human-animal relationship at herd level. This accounts only partly for the VAA test, which seem to be more unclear regarding motivation for the animals' approach behaviour.

Abstract: The responses of eleven pairs of crib-biting and non-crib-biting horses (controls) to an arousal-inducing stimulus were studied. Video-observation of the horses revealed that crib-biting horses spent between 10.4 and 64.7% of their stabling time performing the stereotypy. During the first 2 days of an experimental period, the horses were conditioned to receive food from a special bucket. On the third day the food bucket was presented, but the horses were not allowed to feed. Arousal behaviour and crib-biting intensity as well as plasma cortisol concentration, heart rate (HR) and heart rate variability (HRV) were recorded at rest, and during and after presentation of the food stimulus. The stimulus induced a significant increase of HR and arousal behaviour in crib-biters and in controls, whereas the crib-biting frequency decreased. Power spectral analysis of the HRV revealed significant differences between crib-biters and controls at rest: crib-biters had a lower vagal tone (high frequency component, HF) and a higher sympathetic tone (low frequency component, LF) than controls. The lower basal parasympathetic activity might be an indication why crib-biting horses, in contrast to the controls, showed neither a significant decrease of the HF component during presentation of the food stimulus nor an increase of the HF component after presentation. Thus, there might be differences in the tuning of the autonomous nervous system and of the stress reactivity in crib-biting and in control horses. The results suggest that the crib-biting horses are more stress sensitive and physiologically and psychologically less flexible than the control horses.