Abstract: There is not much research done on the influence of sympathetic training on the emotional reaction
of horses. The aim of the present study was to evaluate the emotional response and the stress level
in horses to two sympathetic training methods: (1) with the use of the “round pen technique” (RP),
and (2) in which the RP was not applied (SH). Twenty two half-bred Anglo-Arab horses (2.5
years ±3 months of age) were subject to an initial training. Eleven horses were randomly included
to the RP method and the other 11 horses for the SH method. Heart rate (HR) and saliva cortisol
concentration were measured as indicators of horse emotional arousal and stress level, respectively.
The HR values were analysed: at rest, during the habituation period, just after the first saddling
and tightening of the girth, during the first time a human leaned over the horse’s back, and during
the mounting of the horse. Saliva samples were taken before and 15 min after each training session
studied. After saddling, the HR occurred significantly higher when the RP technique was used. The
significant increase in saliva cortisol concentration was observed only after the first mounting of
the horse. Generally, the use of the RP technique did not involve more important physiological
reactions in the trained horses than did the SH method.

Abstract: Mortality is high in zoo-housed black rhinoceros (Diceros bicornis), and the reproductive rates of captive white rhinoceros (Ceratotherium simum) are unsustainably low. To determine the possible role of stress in the causation of these problems, we analyzed weekly fecal samples collected for 1 year from black (10 males and 16 females) and white (six males and 13 females) rhinoceroses at 16 zoos for corticoid metabolite concentrations. Fecal corticoid profiles were examined in relation to behavior as rated by keepers in a questionnaire, luteal phase ovarian cycles of females (Brown et al., 2001), and socioenvironmental factors. We compared individual fecal corticoid profiles by examining hormone means and variability (i.e., standard deviation (SD) and coefficient of variation (CV)). For the black rhinos, higher mean corticoid concentrations were found at zoos where rhinos were maintained in enclosures that were exposed to the public around a greater portion of the perimeter. Higher variability in corticoid excretion was correlated with higher rates of fighting between breeding partners and higher institutional mortality rates. Black rhino pairs that were kept separated exhibited lower corticoid variability and less fighting activity when they were introduced during female estrous periods compared to pairs that were kept together every day. For white rhinos, significantly lower mean corticoids were found for individuals that rated higher on “friendliness to keeper.” Higher corticoid variability was found in noncycling as compared to cycling white rhino females. Noncycling females exhibited higher rates of stereotypic pacing and lower frequencies of olfactory behaviors. Interindividual differences in mean corticoids in both species appeared to be related to responsiveness to humans, whereas corticoid variability was related to intraspecific social relationships. More importantly, high corticoid variability appeared to be an indicator of chronic or “bad” stress, because of its association with potentially deleterious consequences in each species (i.e., fighting and mortality (black rhino), and reproductive acyclicity (white rhino)). Our results provide evidence that social stressors may cause chronic stress in black and white rhinos, and that this contributes to the captive-population sustainability problems observed in each species. Zoo Biol 0:1–18, 2005. © 2005 Wiley-Liss, Inc.

Abstract: Horses kept in stalls are deprived of opportunities for social interactions, and the performance of natural behaviors is limited. Inadequate environmental conditions may compromise behavioral development. Initial training is a complex process and it is likely that the responses of horses may be affected by housing conditions. Sixteen 2-year-old Arabian horses were kept on pasture (P) (n=8) or in individual stalls (S) (n=8). Twelve horses (six P and six S) were subjected to a standardized training procedure, carried out by two trainers in a round pen, and 4 horses (two P and two S) were introduced to the round pen but were not trained (C; control). On sample collection day 0, 7, 21 and 28, behavior observations were carried out, blood samples were drawn and heart rates were monitored. Total training time for the stalled horses was significantly higher than total time for the pastured horses (S: 26.4+/-1.5 min; P: 19.7+/-1.1; P=0.032). The stalled group required more time to habituate to the activities occurring from the start of training to mounting (S: 11.4+/-0.96; P: 7.3+/-0.75 min; P=0.007). Frequency of unwanted behavior was higher in the stalled horses (S: 8.0+/-2.0; P: 2.2+/-1.0; P=0.020). Pastured horses tended to have higher basal heart rates on day 0 (S: 74.7+/-4.8; P: 81.8+/-5.3 bpm; P=0.0771). While the physiological data failed to identify differences between housing groups, the behavioral data suggest that pasture-kept horses adapt more easily to training than stalled horses.

Abstract: Horse trailers are a common form of transportation for horses and ponies and often require the animal to travel alone or with a single companion. The current study investigated the effect of transporting horses alone, in company or with an acrylic safety mirror (measuring 81cm61.5cm) that provided surrogate companionship. The behavioural and physiological responses of 12 mature horses during a 30-min journey by trailer under the three treatments were compared. Behaviours (vocalisation, eating, head-tossing, pawing, and head-turning) were recorded. In order to assess circulatory changes that occur as part of the response to transport, heart rate (HR), rectal (Tr) and ear-pinna (Tp) temperatures were recorded. When travelling with a live companion significantly less time was spent vocalising (p<0.001), head-turning (p<0.001), head-tossing (p<0.01) and pawing (p<0.01); eating behaviour increased (p<0.05). Physiological responses (increases in HR and Tr and decreases in Tp) were also significantly reduced when travelling with a live companion (p<0.01). Travelling with the mirror did not significantly affect physiological responses compared with travelling alone, but the rise in Tr and fall in Tp was reduced (p=0.052 and p=0.051, respectively) and can be considered a trend. When travelling with a mirror significantly less time was spent turning the head (p<0.01), vocalising (p<0.05) and head-tossing (p<0.05); eating behaviour increased (p<0.05). The only significant difference between travelling with a live companion and a mirror was that the time spent turning the head round was less with a live companion (p<0.05). The provision of surrogate companionship in the form of a mirror was found to be preferable to travel alone, but where possible a live companion is recommended. Isolation during transportation was found to suppress feeding behaviour. Although peripheral blood flow (Tp) has been used to assess transport stress in other species it has not previously been used in the horse. Further evaluation of this non-invasive measure is now required.

Abstract: Behavioral and physiological changes were studied following prolonged exposure to social competition in pairs of non-food-deprived rats competing daily for a limited supply of graham cracker crumbs. Stable dominant-subordinate relationships developed in most pairs, as measured by feeding time, which were maintained over a 5-6-week study period. In other behavioral tests, subordinates demonstrated a decreased latency to immobility in the forced swim test compared with dominants, but no difference in locomotor activity. Subordinates had increased bladder size, decreased adrenal gland size, and a 35% reduction of hippocampus cell proliferation compared with the dominant member. Therefore, prolonged social competition, based on restricted access to palatable substances, produced hierarchies among individuals that were associated with differences in behavior, physiology and hippocampal cell proliferation.