Abstract: Weaning foals marks a stressful event in horses' lives. Limited research exists regarding different housing methods post-weaning and the long-term implications on horse behavior and welfare. The purpose of this study was to monitor behavior and physiological stress markers in horses weaned individually in solid partition box stalls versus horses weaned in small groups and housed in paddocks. Both treatment groups underwent maternal deprivation stress, but the stalled weanlings had the additive effects of social isolation which prevented them from performing social behaviors. Quarter Horse weanlings from the Michigan State University, Merillat Equine Center, average age 4.5 months, were weaned in 13.4 m2 box stalls (n=6) or in groups of three in a 992 m2 paddock, which had very limited grazing forage and an open shelter available (n=6). Subjects were fed concentrate and hay to National Research Council recommendations. A time budget for 31 observed behaviors was developed. Behavioral observations were made 2 days per week, approximately 6 h per day, for the duration of the 56 days study. Instantaneous samples were recorded every 5 min on each observation day, with equal division between the two treatment groups (n=35 scans per horse per observation day). Focal data were recorded continuously between scans to provide a more detailed ethogram. On each observation day, fecal samples were collected to measure 11,17-dioxoandrostanes, an indicator of glucocorticoid metabolite concentration. Regarding the fecal 11,17-dioxoandrostanes, there was no discernible treatment difference either immediately post-weaning or at the conclusion of the 56 days study. Interestingly, all 12 weanlings showed a 4 week post-weaning increase in 11,17-dioxoandrostanes. The reason for this peak was unclear. Behavioral observations demonstrated a significantly different time budget in paddock-housed weanlings than in stall-housed weanlings (P<0.0001). Paddock-housed weanlings displayed a time budget more like a feral horse time budget, showing more time spent moving and less time spent lying. Paddock-housed weanlings, who had the option of selectively engaging in a broader range of behaviors, showed strong motivation to graze and be near conspecifics. Stalled weanlings spent significantly more time engaged in aberrant behaviors: licking or chewing the stall/shed wall, kicking at the stall/shed wall, pawing, and bucking/rearing bouts (P<0.03). Based on the variety of behaviors shown, the ability to engage in strongly preferred behaviors, and freedom from aberrant behavior, we conclude that the paddock-reared, group-housed weanlings had better welfare. However, there was insufficient evidence to conclude that the stalled weanlings had poor welfare.

Abstract: Domestic fowl were deprived of the opportunity to perform litter-related behaviour for three or four days and were tested in a Y-maze (which they had previously been trained to run) for their ability to associate a coloured cue with gaining access to peat. When the goal boxes were within sight of the choice point, most birds chose peat. However, when the birds had to rely solely on the coloured cue only one bird from 12 showed learning. However, the birds seemed to have some expectation of a reward, as they ran faster if, on the previous trial, they had chosen peat. The inability of the birds to learn the association may have been an artefact of the schedule of deprivation and testing, for when they were hungry and tested in the same way they were again unable to learn an association between the same coloured cue and food reward. The experiment with peat was repeated using “massed” trials (several trials in immediate succession) during training and testing and six from 15 birds showed learning. These results suggest that the initial failure to learn was probably due to the training and testing schedule, that access to peat appears to be rewarding and that hens can learn an association between an abstract cue and a rewarding consequence. This is consistent with the possibility that domestic fowls may have some cognitive representation of peat when it is out of sight.

Abstract: Demand curves were generated for five domestic hens under progressive-ratio 5 schedules of food delivery and under fixed-ratio schedules of food delivery that began at fixed-ratio 5 and were incremented by 5 each session. All sessions ended after 10 consecutive minutes without a response. Although response rates at a given ratio were higher under the progressive-ratio schedule, all hens completed higher ratios under the fixed-ratio schedule. Similar, but not identical, demand curves were generated under progressive-ratio and fixed-ratio schedules. Under both schedules, consumption (reinforcers earned) decreased as cost (ratio size) increased. Data generally were well described by an equation in which elasticity of demand is constant, although an equation in which elasticity could vary accounted for slightly more of the variance.

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: 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.