Abstract: Many breeding organisations include a subjective scoring of rideability by a professional rider into their evaluation of sports horses, but the consistency and reliability of the scoring system is debateable. The aim of this study was to investigate (i) whether professional riders agree in their scoring of rideability, and (ii) whether rideability scores are affected by rein tension, horse conflict behaviour, heart rate, and salivary cortisol, and (iii) whether riders induce different levels of conflict behaviour and physiological responses in the horses. Ten professional, female riders each rode 10 dressage horses (level M German scale; n = 100 combinations) through a standardised dressage test (10 min warm-up followed by a 4-min test) and subsequently scored the horses for rideability on the official 1-10 scale (1 = poor to 10 = excellent) from the Danish Riding Federation. Rein tension, horse heart rate, saliva cortisol and conflict behaviour were measured for each rider-horse pair. The riders were inconsistent in their scoring of rideability to the individual horses, e.g. scores for one of the horses ranged from 1 to 8. There was a significant effect of rider (P = 0.003) and the frequency of conflict behaviour (undesired head movements: P < 0.001, breaking the gait: P = 0.013, and other evasive behaviour: P = 0.032) on rideability scores, i.e. the more conflict behaviour the lower the score. There was no significant effect of rein tension and the physiological measures on rideability scores. However, there was a significant effect of rider on rein tension, horses' heart rate and increases in saliva cortisol concentrations and a tendency for some types of conflict behaviour, suggesting that some riders induced more discomfort in the horses. Future studies could help shed light on which elements of riding style are particularly important for sports horse welfare. In conclusion, this study found a large variation in rideability scores assigned to ten sports horses by ten professional riders. Rideability scores were dependent on the level of horse conflict behaviour, but not rein tension and physiological measures. Further studies are needed to improve the objectivity, consistency and reliability of rideability assessment of sports horses.

Abstract: Abstract— We present a study focused on a quantitative estimation of a human-horse dynamic interaction. A set of measures based on magnitude and phase coupling between heartbeat dynamics of both humans and horses in three different conditions is reported: no interaction, visual/olfactory interaction and grooming. Specifically, Magnitude Squared Coherence (MSC), Mean Phase Coherence (MPC) and Dynamic Time Warping (DTW) have been used as estimators of the amount of coupling between human and horse through the analysis of their heart rate variability (HRV) time series in a group of eleven human subjects, and one horse. The rationale behind this study is that the interaction of two complex biological systems go towards a coupling process whose dynamical evolution is modulated by the kind and time duration of the interaction itself. We achieved a congruent and consistent
statistical significant difference for all of the three indices. Moreover, a Nearest Mean Classifier was able to recognize the three classes of interaction with an accuracy greater than 70%. Although preliminary, these encouraging results allow a discrimination of three distinct phases in a real human-animal interaction opening to the characterization of the empirically proven relationship between human and horse.

Abstract: The effect of competition and the influence of age and sex on performance were examined in a study of 18 Thoroughbred racehorses. The horses performed two solo and two competitive runs at 1,200 and 1,600 m for a total of eight runs. No group ran faster during competition, which may have been a reflection of the quality of horses used for this study and their susceptibility to stress-induced impairment of performance. Males showed no significant difference between competitive and solo run times, whereas females were consistently slower during competition. Males ran significantly faster than females in all runs. There was no difference in run times due to age, which may have been due to the high mean age (5.9 yr) of the group. The slower competitive run times may have occurred because of an earlier onset of fatigue when compared with solo runs. Plasma lactate was significantly greater for the 1,200-m competitive than for the solo runs.

Abstract: In various species, sex, hormonal treatments and oestrous-cycle stage have been shown to affect the animal's response in behavioural tests. Few such studies have been performed in the horse. The main aim of the present study was to investigate whether oestrous-cycle stage affects mares' response to a novel object test and isolation test and, in part, to study whether mares, assumed to suffer from oestrous-related behavioural problems, respond differently in these tests when compared with controls. Twelve mares were tested twice, in oestrus and dioestrus, in a crossover design. Seven behavioural and two heart rate variables were measured for the novel object test and two heart rate variables for the isolation test. Oestrous-cycle stage and whether a mare was classified as a 'problem' mare did not affect the mare's response. However, test order, i.e. the cycle stage a mare was tested in first, affected its reaction. This effect could partly be explained by significant differences between test occasions 1 and 2 in three behavioural variables and one heart rate variable (p < 0.05) in the novel object test. The mares explored the novel object more and had a higher mean heart rate in the first test. Exploring the novel object more could largely be attributed to those mares tested in dioestrus first, perhaps indicating that the mares in oestrus were less receptive to the novel object. The reason for the differences between test occasions could be an effect of learning or habituation.