Paolo Baragli

Post-conflict friendly reunion in a permanent group of horses (Equus caballus).

Gregarious animals living in permanent social groups experience intra-group competition. Conflicts over resources can escalate into costly aggression and, in some conditions, non-dispersive forms of conflict resolution may be favoured. Post-conflict friendly reunions, hence reconciliation, have been described in a variety of species. The aim of this study was to explore, for the first time, the occurrence of reconciliation in a group of domestic horses (Equus caballus) and learn more about strategies used to maintain group cohesion. The behaviour of seven horses living as permanent group in an enclosure for at least 2 years was observed by video for 108h from June to August 2007. We used a Post-Conflict/Matched Control method to assess the existence of reconciliation and third-party affiliation. Behaviours recorded Post-Conflict, or during Matched Control periods, were classified as affiliative based on previous descriptions of visual communication patterns in horses. The proportion of attracted pairs over total post-conflict situations was significantly greater than the proportion of dispersed pairs, both during dyadic interactions (p<0.001) and during triadic interactions (p=0.002). The results of the present study show that both dyadic reconciliation and third-party post-conflict affiliative interactions form important social mechanisms for managing post-conflict situations in horses.

Behaviour of mean erythrocyte volume during submaximal treadmill exercise in the horse

Abstract: The aim of this work was to study the role of spleen contraction in the modification of circulating erythrocyte mean volume during treadmill exercise in the horse. Red blood cells count (RBC), haematocrit (Hct), haemoglobin (Hgb), mean cellular volume (MCV), mean cellular haemoglobin (MCH), mean cellular haemoglobin concentration (MCHC) and red cell distribution width (RDW) were evaluated in five Haflinger mares performing a submaximal incremental test on the treadmill. Blood was collected every minute during the trial without stopping the treadmill. Significant changes of all measured parameters, except for MCH, have been observed. Hct values increased significantly from the 2nd minute from the start of the test. MCV and MCHC values were significantly different from their basal values from the 6th minute of exercise, with MCV being increased and MCHC decreased, suggesting cellular swelling. Hct modifications during brief submaximal exercise have been shown to be mainly and directly related to mobilization of the pool of red blood cells stored in the spleen. However, the evidence in this study of different times of onset of changes between Hct and erythrocyte indices (MCV and MCHC) suggests that exercise-induced alterations in red cell indices are not related to spleen emptying.

Detour behaviour in horses (Equus caballus)

The objective of this study was to investigate the ability of horses (Equus caballus) to detour around symmetric and asymmetric obstacles. Ten female Italian saddle horses were each used in three detour tasks. In the first task, the ability to detour around a symmetrical obstacle was evaluated; in the second and third tasks subjects were required to perform a detour around an asymmetrical obstacle with two different degrees of asymmetry. The direction chosen to move around the obstacle and time required to make the detour were recorded. The results suggest that horses have the spatial abilities required to perform detour tasks with both symmetric and asymmetric obstacles. The strategy used to perform the task varied between subjects. For five horses, lateralized behaviour was observed when detouring the obstacle; this was consistently in one direction (three on the left and two on the right). For these horses, no evidence of spatial learning or reasoning was found. The other five horses did not solve this task in a lateralized manner, and a trend towards decreasing lateralization was observed as asymmetry, and hence task difficulty, increased. These non-lateralized horses may have higher spatial reasoning abilities.

A Novel Algorithm for Movement Artifact Removal in ECG Signals Acquired from Wearable Systems Applied to Horses

This study reports on a novel method to detect and reduce the contribution of movement artifact (MA) in electrocardiogram (ECG) recordings gathered from horses in free movement conditions. We propose a model that integrates cardiovascular and movement information to estimate the MA contribution. Specifically, ECG and physical activity are continuously acquired from seven horses through a wearable system. Such a system employs completely integrated textile electrodes to monitor ECG and is also equipped with a triaxial accelerometer for movement monitoring. In the literature, the most used technique to remove movement artifacts, when noise bandwidth overlaps the primary source bandwidth, is the adaptive filter. In this study we propose a new algorithm, hereinafter called Stationary Wavelet Movement Artifact Reduction (SWMAR), where the Stationary Wavelet Transform (SWT) decomposition algorithm is employed to identify and remove movement artifacts from ECG signals in horses. A comparative analysis with the Normalized Least Mean Square Adaptive Filter technique (NLMSAF) is performed as well. Results achieved on seven hours of recordings showed a reduction greater than 40% of MA percentage (between before- and after- the application of the proposed algorithm). Moreover, the comparative analysis with the NLMSAF, applied to the same ECG recordings, showed a greater reduction of MA percentage in favour of SWMAR with a statistical significant difference (p–value < 0.0.5).

The role of associative and non-associative learning in the training of horses and implications for the welfare (a review)

Horses were domesticated 6000 years ago and since then different types of approaches have been developed to enhance the horses wellbeing and the human-horse relationship. Even though horse training is an increasingly important research area and many articles have been published on the subject, equitation is still the sport with the highest rate of human injuries, and a significant percentage of horses are sold or slaughtered due to behavioral problems. One explanation for this data is that the human-horse relationship is complex and the communication between humans and horses has not yet been accurately developed. Thus, this review addresses correct horse training based on scientific knowledge in animal learning and psychology. Specifically, it starts from the basic communication between humans and horses and then focuses on associative and non-associative learning, with many practical outcomes in horse management from the ground and under saddle. Finally, it highlights the common mistakes in the use of negative reinforcement, as well as all the implications that improper training could have on horse welfare. Increased levels of competence in horse training could be useful for equine technicians, owners, breeders, veterinarians, and scientists, in order to safeguard horse welfare, and also to reduce the number of human injuries and economic loss for civil society and the public health system.

Effect of aging on behavioural and physiological responses to a stressful stimulus in horses (Equus caballus)

In humans the expression of emotions varies with aging, but for domestic animals we have little information on this subject. Our aim was to verify the influence of aging (life experience) on the expression of emotions in horses (Equus caballus) in reaction to a stressful stimulus. A total of 98 horses were subjected to the sudden inflation of a balloon in a familiar environment for a period of 5 min, on the assumption that this would induce a negative state. When the balloon was inflated, heart rate variability as an indicator of stress response was monitored. Behaviour related to emotional expression (latency of onset, frequency and length of looking and exploration, frequency of avoidance) was also monitored. The younger horses showed a significantly higher frequency of avoidance as well as greater exploratory activity, while the older subjects were less behaviourally responsive and showed a shift toward control by the sympathetic nervous system, as indicated by lower heart rate variability. The results suggest that aging influences the behaviour and physiology of emotional expression to stressful stimuli in horses. Knowing the effect of aging on stress response could be a critical factor in understanding equine welfare and the development of behavioural patterns.

Application of a constant blood withdrawal method in equine exercise physiology studies

The aim of the present study was to test a constant blood withdrawal method (CBWM) to collect blood samples from horses during treadmill exercise. CBWM was performed in 4 Standardbreds and 5 Haflinger horses. A peristaltic pump was used to control blood aspiration from an i.v. catheter via an extension line. Blood was collected using an automatic fractions collector, with a constant delay time between the drawing of blood and sample collection. Blood withdrawal using CBWM was made during a treadmill standardised exercise test (SET). A blood flow of 12 m/min was used and samples collected every 60 s during the entire period of exercise. The volume of blood collected in each sample tube was 12.1+/-0.2 ml, with a delay time of mean +/- s.d. 25.3+/-0.8 s. Plasma lactate kinetics based on measurement of lactate in each fraction showed an exponential increase during the first 13 min of exercise (10.5 min of SET and 2.5 min recovery). The peak plasma lactate concentration was observed between 2.5 and 5.5 min after the end of SET. CBWM permits the kinetics of lactate and other blood-borne variables to be studied over time. This method could be a valuable aid for use in studying equine exercise physiology.

Removing movement artifacts from equine ECG recordings acquired with textile electrodes.

This study reports on the implementation of a novel system to detect and reduce movement artifact (MA) contribution in electrocardiogram (ECG) recordings acquired from horses in free movement conditions. The system comprises both integrated textile electrodes for ECG acquisition and one triaxial accelerometer for movement monitoring. Here, ECG and physical activity are continuously acquired from seven horses through the wearable system and a model that integrates cardiovascular and movement information to estimate the MA contribution is implemented. Moreover, in this study we propose a new algorithm where the Stationary Wavelet Transform (SWT) decomposition algorithm is employed to identify and remove movement artifacts from ECG recodigns. Achieved results showed a reduction of MA percentage greater than 40% between before- and after- the application of the proposed algorithm to seven hours of recordings.

Brief note about plasma catecholamines kinetics and submaximal exercise in untrained standardbreds

Four untrained standardbred horses performed a standardized exercise test on the treadmill and an automated blood collection system programmed to obtain blood samples every 15 s was used for blood collection in order to evaluate the kinetics of adrenaline and noradrenaline. The highest average values obtained for adrenaline and noradrenaline were 15.0 +/- 3.0 and 15.8 +/- 2.8 nmol/l respectively, with exponential accumulation of adrenaline (r = 0.977) and noradrenaline (r = 0.976) during the test. Analysis of the correlation between noradrenaline and adrenaline for each phase of the test shows that correlation coefficient decreases as the intensity of exercise increases (from r = 0.909 to r = 0.788). This suggests that during submaximal exercise, the process for release, distribution and clearance of adrenaline into blood circulation differs from that of noradrenaline.

Consistency and flexibility in solving spatial tasks: Different horses show different cognitive styles

Individual animals vary in their behaviour and reactions to novel situations. These differences may extend to differences in cognition among individuals. We tested twenty-six horses for their ability to detour around symmetric and asymmetric obstacles. All of the animals were able to get around the barrier to reach a food target, but varied in their approach. Some horses moved slowly but were more accurate in choosing the shortest way. Other horses acted quickly, consistently detoured in the same direction, and did not reliably choose the shortest way. The remaining horses shifted from a faster, directionally consistent response with the symmetric barrier, to a slower but more accurate response with the asymmetric barrier. The asymmetric barrier induced a reduction in heart rate variability, suggesting that this is a more demanding task. The different approaches used to solve the asymmetric task may reflect distinct cognitive styles in horses, which vary among individuals, and could be linked to different personality traits. Understanding equine behaviour and cognition can inform horse welfare and management.