Abstract: The aim of this study was to evaluate the behavior and physiologic responses of mares to removal from an established pasture herd and to isolation in a pasture setting for 6 h (Group I, n=5). Responses of mares in Group I were compared to mares that were transported and returned to the herd (Group T, n=5) and to mares moved to the isolation pasture with a companion (Group C, n=5). Behavior was recorded continuously for 6 h on the day before the isolation procedures (baseline, Day 0) and again on the day of the procedure (test, Day 1). Plasma cortisol, white blood cell count (WBC), neutrophil:lymphocyte ratio (N:L), and hematocrit (HCT) were measured once on Day 0 (a.m.) and twice on Day 1 (a.m. and p.m.). Heart rate (HR) was monitored continuously during Day 0 and Day 1. Intradermal response to phytohemagglutinin (PHA) injection was measured 18 h following injection, which was administered at the end of Day 1. Average time spent standing alert increased (P<0.05) in Groups I and C and average time spent grazing decreased (P<0.05) in Group C from Day 0 to Day 1. Also, there was a significant difference between groups (based on a calculated χ2-square value) in the proportion of mares that autogroomed, defecated, urinated, rolled, and whinnied on Day 1. Activity shift rate (ASR) and temperament scores increased significantly in Groups I and C from Day 0 to Day 1 (P<0.05). Plasma cortisol increased significantly in all groups from Day 0 to Day 1, a.m. (P<0.05) and decreased significantly from Day 1, a.m. to Day 1, p.m. (P<0.05). HCT significantly increased in all three groups from Day 0 to Day 1, a.m. (P<0.05). WBC significantly increased in Group T from Day 0 to Day 1, a.m. (P<0.05). N:L ratio significantly increased in Groups I and C from Day 0 and Day 1, a.m. to Day 1, p.m. (P<0.05). A variety of measures did indicate a response to removal from the pasture group, however, the overall, short-term response was minimal. Since the responses of Groups I and C were similar, the effects of isolation versus a novel environment or separation from the established herd could not be differentiated.

Abstract: This paper demonstrates that the rhesus monkey provides an excellent model to study mechanisms underlying human anxiety and fear and emotion regulation. In previous studies with rhesus monkeys, stable, brain, endocrine, and behavioral characteristics related to individual differences in anxiety were found. It was suggested that, when extreme, these features characterize an anxious endophenotype and that these findings in the monkey are particularly relevant to understanding adaptive and maladaptive anxiety responses in humans. The monkey model is also relevant to understanding the development of human psychopathology. For example, children with extremely inhibited temperament are at increased risk to develop anxiety disorders, and these children have behavioral and biological alterations that are similar to those described in the monkey anxious endophenotype. It is likely that different aspects of the anxious endophenotype are mediated by the interactions of limbic, brain stem, and cortical regions. To understand the brain mechanisms underlying adaptive anxiety responses and their physiological concomitants, a series of studies in monkeys lesioning components of the neural circuitry (amygdala, central nucleus of the amygdala and orbitofrontal cortex) hypothesized to play a role are currently being performed. Initial findings suggest that the central nucleus of the amygdala modulates the expression of behavioral inhibition, a key feature of the endophenotype. In preliminary FDG positron emission tomography (PET) studies, functional linkages were established between the amygdala and prefrontal cortical regions that are associated with the activation of anxiety.

Abstract: Reasons for performing study: Little information exists on the immunological effects of transport or the use of supplements to minimise transport stress. Objectives: To establish baseline ranges and evaluate immunophenotypic and functional changes associated with transport and a nutritional ‘adaptogen’ supplement. Methods: Horses received either supplement (n = 10) or placebos (n = 9) during the 30 day study. After 28 days in stalls, 12 horses (6 supplement; 6 placebo) were transported for 24 h, then unloaded and recovered. Venous blood samples were collected on Days 1, 14 and 28 to establish baselines, and on Days 28, 29 and 30 to examine changes during transport and recovery. Results: Transport prompted elevations (P<0.05) in cortisol concentration, neutrophil count and white blood cell counts, while lymphocyte subpopulation counts (CD3+, CD4+, CD8+, CD21+) decreased (P<0.05). Normal phenotypic lymphocyte profiles returned within 24 h of recovery. Supplement effects on immunophenotype (CD21+ and CD8+) were observed in stabled horses (P<0.05), but not in transported horses. Conclusions: These results provide insights into the immunological mechanisms associated with long-term transport. Potential relevance: The existence of a small window of immunological uncertainty follows long-term transportation, enhancing the potential risk of infectious disease in susceptible individuals.

Abstract: Aim of study was to investigate the effects of transport stress on thyroid response, body weight, rectal temperature and heart rate changes in one hundred twenty-six healthy stallions in basal conditions, before and after short road transport. One hundred twenty-six Thoroughbreds and crossbreds stallions with previous travelling experience, aged 4 to 15 yr, were transported by road in a commercial trailer for a period of 3 h (distance <300 km). Blood samples and physiological parameters were collected at 0800 (basal I) and at 1100 (basal II), in each horse“s box, one week before the loading and transport in basal conditions, and one week later, at 0800 immediately before loading (pre-transport), and after 3 h period of transport and unloading, on their arrival at the breeding stations (post-transport), in each new horse”s box, within 30 min. Increases in circulating T3, T4 and fT4 levels (P < 0.01), but not for fT3 levels, were observed after transport, as compared to before loading values, irrespective of different breed. Lower T4 and fT4 levels were observed in basal II (P < 0.01) than basal I and before loading values (pre-transport). After transport Thoroughbreds showed higher fT3 (P < 0.05) and fT4 (P < 0.01) levels than crossbred stallions. No significant differences for T3 and T4 changes were observed. A significant increase in rectal temperature (P < 0.01) and heart rate (P < 0.05) was observed after transport, as compared to before loading values (pre-transport). No differences between basal I, basal II and before loading values (pre-transport) for physiological parameters were observed.
The highest T3, T4 and fT4 levels recorded after short transport seem to suggest a preferential release from the thyroid gland. The results indicate that short road transport stress contributes significantly to thyroid hormone changes, according to different breed, and to the increase in rectal temperature and heart rate. No differences related to different age were observed.

Abstract: It is widely accepted that transport is stressful for horses, but only a few studies are available involving horses that are transported regularly and are accustomed to transport. We determined salivary cortisol immunoreactivity (IR), fecal cortisol metabolites, beat-to-beat (RR) interval, and heart rate variability (HRV) in transport-experienced horses (N = 7) in response to a 2-d outbound road transport over 1370 km and 2-d return transport 8 d later. Salivary cortisol IR was low until 60 min before transport but had increased (P < 0.05) 30 min before loading. Transport caused a further marked increase (P < 0.001), but the response tended to decrease with each day of transport. Concentrations of fecal cortisol metabolites increased on the second day of both outbound and return transports and reached a maximum the following day (P < 0.001). During the first 90 min on Day 1 of outbound transport, mean RR interval decreased (P < 0.001). Standard deviations of RR interval (SDRR) decreased transiently (P < 0.01). The root mean square of successive RR differences (RMSSD) decreased at the beginning of the outbound and return transports (P < 0.01), reflecting reduced parasympathetic tone. On the first day of both outbound and return transports, a transient rise in geometric HRV variable standard deviation 2 (SD2) occurred (P < 0.01), indicating increased sympathetic activity. In conclusion, transport of experienced horses leads to increased cortisol release and changes in heart rate and HRV, which is indicative of stress. The degree of these changes tended to be most pronounced on the first day of both outbound and return transport.