Goats (Capra hircus) From Different Selection Lines Differ in Their Behavioural Flexibility.

Given that domestication provided animals with more stable environmental conditions, artificial selection by humans has likely affected animals' ability to learn novel contingencies and their ability to adapt to changing environments. In addition, the selection for specific traits in domestic animals might have an additional impact on subjects' behavioural flexibility, but also their general learning performance, due to a re-allocation of resources towards parameters of productivity. To test whether animals bred for high productivity would experience a shift towards lower learning performance, we compared the performance of dwarf goats (not selected for production, 15 subjects) and dairy goats (selected for high milk yield, 18 subjects) in a visual discrimination learning and reversal learning task. Goats were tested individually in a test compartment and were rewarded by choosing either a white or a black cup presented by the experimenter on a sliding board behind a crate. Once they reached a designated learning criterion in the initial learning task, they were transferred to the reversal learning task. To increase the heterogeneity of our test sample, data was collected by two experimenters at two research stations following a similar protocol. Goats of both selection lines did not differ in the initial discrimination learning task in contrast to the subsequent reversal learning task. Dairy goats reached the learning criterion slower compared to dwarf goats (dairy goats = 9.18 sessions; dwarf goats = 7.74 sessions; P = 0.016). Our results may indicate that the selection for milk production might have affected behavioural flexibility in goats. These differences in adapting to changing environmental stimuli might have an impact on animal welfare e.g., when subjects have to adapt to new environments or changes in housing and management routines.

Determining suitable dimensions for dairy goat feeding places by evaluating body posture and feeding reach.

Confined goats spend a substantial part of the day feeding. A poorly designed feeding place increases the risk of feeding in nonphysiological body postures, and even injury. Scientifically validated information on suitable dimensions of feeding places for loose-housed goats is almost absent from the literature. The aim of the present study was, therefore, to determine feeding place dimensions that would allow goats to feed in a species-appropriate, relaxed body posture. A total of 27 goats with a height at the withers of 62 to 80 cm were included in the study. Goats were tested individually in an experimental feeding stall that allowed the height difference between the feed table, the standing area of the forelegs, and a feeding area step (difference in height between forelegs and hind legs) to be varied. The goats accessed the feed table via a palisade feeding barrier. The feed table was equipped with recesses at varying distances to the feeding barrier (5-55 cm in 5-cm steps) at angles of 30°, 60°, 90°, 120°, or 150° (feeding angle), which were filled with the goats' preferred food. In 18 trials, balanced for order across animals, each animal underwent all possible combinations of feeding area step (3 levels: 0, 10, and 20 cm) and of difference in height between feed table and standing area of forelegs (6 levels: 0, 5, 10, 15, 20, and 25 cm). The minimum and maximum reach at which the animals could reach feed on the table with a relaxed body posture was determined for each combination. Statistical analysis was performed using mixed-effects models. The animals were able to feed with a relaxed posture when the feed table was at least 10 cm higher than the standing height of the goats' forelegs. Larger goats achieved smaller minimum reaches and minimum reach increased if the goats' head and neck were angled. Maximum reach increased with increasing height at withers and height of the feed table. The presence of a feeding area step had no influence on minimum and maximum reach. Based on these results, the goats' feeding place can be designed to ensure that the animals are able to reach all of the feed in the manger or on the feed table with a relaxed posture, thus avoiding injuries and nonphysiological stress on joints and hooves. A feeding area step up to a maximum of 20 cm need not be taken into account in terms of feeding reach. However, the feed table must be raised at least 10 cm above the standing area to allow the goats to feed in a species-appropriate, relaxed posture.

Context Specificity of the ANS Stress Response during Two Regrouping Experiments in Goats.

The aim of this study was to analyze whether the activity of the autonomic nervous system (ANS) differs between two regrouping procedures in goats, which would indicate stimulus specificity of these stressors. Applying two regrouping procedures, we evaluated heart rate and heart rate variability (RMSSD, SDNN, and RMSSD/SDNN). The two regrouping procedures were (1) introduction of individual goats into established groups ("introduction experiment") and (2) temporary separation and subsequent reintegration of individuals from/into their group with two levels of contact during separation ("separation experiment"). In the "introduction experiment," the heart rate of introduced goats while lying decreased continuously from an average 78 to 68 beats/min from before the introduction to the last day of the introduction period. Inversely, RMSSD increased continuously from 41 to 62 ms, which, on its own, would indicate an adaptation to the situation. During the "separation experiment," heart rate while lying was higher when goats were separated in the "acoustic contact treatment" (82 beats/min on average) compared with the "restricted physical contact treatment" (75 beats/min on average). This difference reflected a higher level of arousal during the "acoustic contact treatment." However, heart rate activity did not allow detecting effects of separation or reintegration. Even though it can be assumed that both the separation and introduction of goats are stressful for goats, the ANS reactions observed in this study differed between the two management procedures indicating that the ANS activation was specific to each situation. In addition, we discuss the ANS results in context with earlier findings of variables of the hypothalamic pituitary adrenal (HPA) axis (fecal cortisol metabolites) and behavior (lying and feeding). As correspondence between ANS, HPA, and behavioral reactions was limited both within and across experiments, the results of this study underline the concept that stress response patterns are context specific.

Are head cues necessary for goats (Capra hircus) in recognising group members?

In this study, we investigated whether goats can distinguish a member of their own group from one belonging to a different group even when the head of the goat in question cannot be seen. In the experiment, a total of 45 adult female goats (walkers) were trained to walk along a passageway at the end of which they learnt to expect food (trial run). Walking down this corridor, they passed another adult female goat (stimulus goat) whose trunk and hind legs alone were visible. Using 19 individuals, ten pairs of stimulus goats consisting of one goat from the walker's group and one from a different group were matched in terms of body size, constitution, colour and coat length. In addition, the stimulus goat from the same group as the walker had to be higher ranking than the latter to avoid being attacked. The walkers completed two, four or six trial runs depending on the number of pairs suitable for a given walker. The walker's exploratory behaviour (observing and sniffing at the stimulus goat) was recorded. Data from 109 trial runs were analysed using generalised linear mixed-effects models with crossed random effects. On average, the walker spent a total of 8.7 s exploring the stimulus goat visually and olfactorily if the latter was from a different group and only about half as long (4.2 s) if it was from her own group. In particular, the time a walker spent observing a stimulus goat whilst approaching the latter was significantly longer if the stimulus goat belonged to a different group than to her own (2.5 s as opposed to 1.4 s). Moreover, a stimulus goat from a different group was sniffed at significantly longer (4.6 s) than one from the same group (1.9 s). Results suggest that goats can easily discriminate between members of their own group and those of a different group even when the latter's heads are hidden. Olfactory and visual cues are probably important for identifying group members.

Cardiac activity in dairy goats whilst feeding side-by-side at two different distances and during social separation.

When loose-housed dairy goats feed in close proximity to each other, frequent social conflicts are often reported. The aim of this study was to investigate whether the cardiac activity of dairy goats is affected when they are obliged to feed side-by-side in close proximity. In five dyads of goats each stemming from eight groups (8x5 dyads) differing in terms of grouping age and presence of horns, heart rate (HR) and root mean square of successive beat-to-beat differences (RMSSD) as a parameter of heart-rate variability were measured in two experimental situations differing in distance during feeding. Dyads were allowed to feed for 5 min at two hayracks set-up side-by-side at a "far" or a "near" distance. Before goats were exposed to these test situations, baseline values of cardiac activity were measured. The differences of the baseline and test values (Delta) for HR and RMSSD were used for statistical analysis with linear mixed-effects models with crossed random effects. They were tested for dependence on feeding distance, rank within the group, dyadic rank relationship, grouping age, and presence of horns. In addition, cardiac activity was measured in a social-separation experiment conducted with the same goats. Baseline cardiac activity depended on the goat's rank within the group, with higher/lower levels of RMSSD/HR found in high-ranking than in low-ranking goats. In the feeding experiment, a significant interaction (feeding distance*rank within group, p=0.01) was found for Delta RMSSD: Low-ranking goats had lower Delta values at the far than at the near feeding distance. By contrast, high-ranking goats had lower Delta values at the near than at the far distance. In the separation experiment, Delta HR increased significantly compared to the feeding experiment (p<0.05), whereas Delta RMSSD did not differ significantly. Our results show that cardiac response is context-specific in dairy goats (feeding vs. separation), and that the individual's rank within the group must be taken into account in any future studies of their cardiac activity.