Abstract: Four methods of ranking horses on reactivity were evaluated and compared: isolation from conspecifics, presentation of a static novel stimulus, traversing a novel stimulus in a runway (isolation, novel stimulus and runway tests, respectively) and assigning subjective emotionality scores. In all tests, horses' heart rates were recorded and behaviour was videotaped. To be considered a valid test of reactivity, at least one heart rate and one behavioural measurement in the test had to change significantly between treatments (tranquilizer administation versus sham tranquilizer administration), and behavioural measures had to be displayed in at least 75% of the trials. Forty horses performed each of the three tests daily on three different days in a switchback design. Horses were assigned randomly to a daily test sequence, which was maintained throughout the study. In the runway test, no significant difference in heart rate values in tranquilized and non-tranquilized horses was found, and no behavioural attribute was displayed in more than 52% of the trials; therefore it was rejected as a valid test of reactivity. Both isolation and novel stimulus tests produced valid measurements. Mean heart rate was the most precise physiological measure for these tests, and walking and defecation frequency were the most precise behavioural measures for novel stimulus and isolation tests, respectively. Mean heart rates on the novel stimulus and isolation tests were correlated (rs = 0.79, P < 0.01) indicating that these tests produced similar rankings based on physiological responses. However, behavioural measures ranked horses differently (rs = 0.27, P < 0.10) on the tests. Rank correlations between mean heart rates and behavioural measures were higher in the novel stimulus (rs = 0.66, P < 0.01) than the isolation test (rs = 0.55, P < 0.01), indicating that the novel stimulus test ranked horses based on either physiological or behavioural responses more similarly than did the isolation test. Therefore, the novel stimulus test was considered the more accurate evaluation of reactivity. Subjective emotionality scores were correlated moderately with mean heart rates (rs > 0.33, P < 0.01) from the novel stimulus and isolation tests and with walking scores (rs = 0.47, P < 0.01) from the novel stimulus test. Assignment of subjective emotionality scores was not as accurate as the novel stimulus or isolation tests in ranking horses for reactivity. Using physiological data alone, combining physiological and behavioural measurements or using more than one behavioural measurement in reactivity tests may reflect the reactivity of the horse better than a single behavioural measurement.

Abstract: The first month of training of a young horse is suspected to be stressful, but the endocrine responses to initial training are unknown. Therefore in our study a total of 40 Quarter Horses (QH), all at the age of almost 2 years, were followed during the first 30 days of their training. During this time faecal samples were collected twice daily and faecal cortisol metabolites (FCM) were measured. Baseline values of FCM ranged between 1.3 and 20.1 (median: 6.7) ng/g faeces. No differences in FCM values between days of training were found. Mares showed the highest values. Significant diurnal variations were observed in mares (p=0.035) and stallions (p=0.003), but not in geldings (p=0.282). As in this study adrenocortical activity was not increased during initial training, horses seem to cope very well with this new situation. The results of our large-scale study provide basic physiological data about initial training. This gives additional input in an emotional debate about animal welfare aspects of first time handling and training of horses.
Abbreviations: 11,17-DOA = 11,17-dioxoandrostanes; EIA = Enyzme Immunoassay; FCM = faecal cortisol metabolites; GC = glucocorticoids; HPA-axis = hypothalamic-pituitary-adrenocortical-axis; QH = Quarter Horses
[Das Einreiten eines jungen Pferdes steht unter Verdacht belastend zu sein. Bisher gibt es aber keine Veröffentlichungen über endokrine Vorgänge während dieser Phase. Mit der vorliegenden Studie wurde überprüft, ob Pferde aufgrund physischer und psychischer Belastungen während des Trainings höhere Konzentrationen an Kortisolmetaboliten im Kot (FCM) aufweisen. Es wurden dazu 40 Quarter Horses im Alter von 2 Jahren während der ersten 30 Tage der Grundausbildung des Westernreitens beobachtet und ihre FCM Werte gemessen. Während dieser Zeitspanne wurden täglich morgens und abends Kotproben der Pferde genommen. Die Basalwerte der FCM Konzentration variierten zwischen 1,3 und 20,1 (Median: 6,7) ng/g Kot, wobei Stuten die höchsten Werte hatten. Signifikante Unterschiede während der einzelnen Trainingstage konnten nicht festgestellt werden. In der Tagesrhythmik wurden signifikante Unterschiede bei Stuten (p=0,035) und bei Hengsten (p=0,003), jedoch nicht bei Wallachen (p=0,282) ermittelt. In dieser Studie konnte keine erhöhte Aktivität der Nebennierenrinde im Verlauf der Grundausbildung eines Pferdes im Westernreitstil festgestellt werden. Das legt nahe, dass Pferde mit dieser neuen, zeitlich kurz andauernden Situationen gut zurechtkommen. Unsere Studie wurde an einer großen Anzahl von Tieren unter Feldbedingungen durchgeführt. Sie bietet daher eine gute Datenbasis über Belastungen während des Einreitens. Damit liefert sie einen zusätzlichen Beitrag zu einer mitunter emotional geführten Debatte über tierschutzrelevante Aspekte bei der Grundausbildung von Pferden.]

Abstract: Sweating responses were examined in five horses during a standardized exercise test (SET) in hot conditions (32-34 degrees C, 45-55% relative humidity) during 8 wk of exercise training (5 days/wk) in moderate conditions (19-21 degrees C, 45-55% relative humidity). SETs consisting of 7 km at 50% maximal O(2) consumption, determined 1 wk before training day (TD) 0, were completed on a treadmill set at a 6 degrees incline on TD0, 14, 28, 42, and 56. Mean maximal O(2) consumption, measured 2 days before each SET, increased 19% [TD0 to 42: 135 +/- 5 (SE) to 161 +/- 4 ml. kg(-1). min(-1)]. Peak sweating rate (SR) during exercise increased on TD14, 28, 42, and 56 compared with TD0, whereas SRs and sweat losses in recovery decreased by TD28. By TD56, end-exercise rectal and pulmonary artery temperature decreased by 0.9 +/- 0.1 and 1.2 +/- 0.1 degrees C, respectively, and mean change in body mass during the SET decreased by 23% (TD0: 10.1 +/- 0.9; TD56: 7.7 +/- 0.3 kg). Sweat Na(+) concentration during exercise decreased, whereas sweat K(+) concentration increased, and values for Cl(-) concentration in sweat were unchanged. Moderate-intensity training in cool conditions resulted in a 1.6-fold increase in sweating sensitivity evident by 4 wk and a 0.7 +/- 0.1 degrees C decrease in sweating threshold after 8 wk during exercise in hot, dry conditions. Altered sweating responses contributed to improved heat dissipation during exercise and a lower end-exercise core temperature. Despite higher SRs for a given core temperature during exercise, decreases in recovery SRs result in an overall reduction in sweat fluid losses but no change in total sweat ion losses after training.

Abstract: Continuous direct measurement of feline arterial blood pressure (ABP) was carried out via a modified method with percutaneous, ultrasound guided catheterization of the common carotid artery. In 21 healthy, conscious cats the ABP was measured during rest, alertness and activity. Furthermore, the ABP response to being petted by familiar and unfamiliar persons was assessed. Linear mixed modelling revealed that the mean blood pressure (MBP) in resting cats (114.6 mmHg) was lower (P < 0.001) than in alert cats (122.7 mmHg), which was lower (P < 0.001) than that of active cats (136.8 mmHg). The MBP during petting by a familiar person (144.7 mmHg) tended to be higher (P = 0.065) than that during petting by an unfamiliar person (139.4 mmHg). The MBP of active cats was lower (P = 0.003) than MBP of cats petted by a familiar person, but not different from MBP of cats petted by an unfamiliar person. The MBP returned to resting values between 16 and 20 min after the familiar person had left, whereas resting values were reached between 11 and 15 min after the unfamiliar person had left. The complications of the described method were limited considering the potential risks of continuous direct ABP measurement. In conclusion, the described technique enables accurate measurement of feline ABP, which is influenced by the cat's activity level and the familiarity of persons.

Abstract: A group of animals can only move cohesively, if group members “somehow” reach a consensus about the timing (e.g., start) and the spatial direction/destination of the collective movement. Timing and spatial decisions usually differ with respect to the continuity of their cost/benefit distribution in such a way that, in principle, compromises are much more feasible in timing decision (e.g. median preferred time) than they are in spatial decisions. The consequence is that consensus costs connected to collective timing decisions are usually less skewed amongst group members than are consensus costs connected to spatial decisions. This, in turn, influences the evolution of decision sharing: sharing in timing decisions is most likely to evolve when conflicts are high relative to group cohesion benefits, while sharing in spatial decisions is most likely to evolve in the opposite situation. We discuss the implications of these differences for the study of collective movement decisions.