Abstract: The design of a captive environment should facilitate the expression of the natural behavioural repertoire of the species concerned. The domestic horse (Equus caballus) is a social, herd dwelling species that is often housed in isolation from con-specifics or kept in groups in paddock enclosures. Although the latter allows for social interaction and does not restrict movement per se, it may not promote natural activity patterns or group cohesion. The aim of the current study was to assess the impact of two different paddock designs on the behaviour of a stable group of horses (n=6: 2 mares, 4 geldings).
The paddock designs tested were adjacent and grassed similarly, but configured differently. A central paddock (75 x 75m) designated NT, was surrounded by a track 1.6-5.5m wide, designated T. The horses were turned out in their group into T or NT for 3 consecutive days. Their behaviour was recorded for one hour three times each day (10.00, 13.00, 16.00 hrs). Within each observation period of one hour focal sampling was used, each individual horse being observed for a 10 minute period. They were then moved to the other enclosure type for a further 3 consecutive days, followed by a repeat of each condition. When turned out the horses were fitted with a global positioning system device (Garmin Forerunner 305) to monitor distance travelled and speed for the period 10.00-17.00 hrs. The mean percentage of time spent in each behavioural state (standing alert, standing resting, walk/trot, grazing, lying, social interaction) during the periods observed was calculated. Behaviour during social interactions was classified as either affiliative (approach, follow, friendly contacts, mutual grooming) or agonistic (approach and retreat, bite, chase, head threat).
The horses travelled significantly further in T than in NT (paired samples t-test: t (5) = 11.74, p<0.001) and moved significantly faster (Wilcoxon signed rank test: z = -2.21, p=0.03). See Table 1. When the percentage of time spent in each behavioural state in T and NT was compared some significant differences were found. A significantly higher percentage of time was spent active (walking /trotting) in T than in NT (paired samples t-test: t (5) = 5.74, p=0.002). Standing alert was only recorded in T (paired samples t-test: t (5) = 3.48, p=0.02). A significantly higher percentage of time was spent grazing in NT than in T (paired samples t-test: t (5) = -3.58, p=0.016). Significantly more social interaction occurred in T than in NT (paired samples t-test: t (5) = 5.93, p=0.002). See Figure 1. In T, 91% of social interactions were affiliative and 9% agonistic, whereas in NT 29% were affiliative and 71% agonistic. No difference was found in the percentage of time spent standing resting or lying down in T and NT.
The benefits of housing horses in groups as opposed to individually have been demonstrated in previous studies. In addition to better satisfying the behavioural needs of the horse it has been found that group housed horses adapt more easily to training and display less undesirable behaviour than those housed individually (Rivera et al. 2002; Søndergaard and Ladewig 2004; Visser et al. 2008). However, individual housing is frequently selected by horse owners in preference to group housing to avoid the risk of injury during agonistic encounters. Fureix et al. (2012) suggest that management practices may well contribute to aggressiveness in horses and that the conditions under which we keep horses should be reviewed. The findings of the present study indicate that the design of the enclosure in which groups of horses are kept affects the nature of social interactions. The T paddock design resulted in reduced intra-group aggression. However, this paddock design also reduced the time spent grazing and increased vigilant behaviour. Although the results demonstrate that a paddock system including tracks may facilitate group cohesion and more natural movement patterns, the long-term impact on behaviour and welfare requires further investigation.
References:
Fureix C, Bourjade M, Henry S, Sankey C, Hausberger M. (2012). Exploring aggression regulation in managed groups of horses (Equus caballus). Applied Animal Behaviour Science 138: 216-228.
Rivera E, Benjamin S, Nielsen B, Shelle J, Zanella AJ. (2002). Behavioural and physiological response of horses to initial training: the comparison between pastured versus stalled horses. Applied Animal Behaviour Science 78: 235–252.
Søndergaard E, Ladewig J. (2004). Group housing exerts a positive effect on the behaviour of young horses during training. Applied Animal Behaviour Science 87: 105-118.

Abstract: Human declarative memory involves a systematic organization of information that supports generalizations and inferences from acquired knowledge. This kind of memory depends on the hippocampal region in humans, but the extent to which animals also have declarative memory, and whether inferential expression of memory depends on the hippocampus in animals, remains a major challenge in cognitive neuroscience. To examine these issues, we used a test of transitive inference pioneered by Piaget to assess capacities for systematic organization of knowledge and logical inference in children. In our adaptation of the test, rats were trained on a set of four overlapping odor discrimination problems that could be encoded either separately or as a single representation of orderly relations among the odor stimuli. Normal rats learned the problems and demonstrated the relational memory organization through appropriate transitive inferences about items not presented together during training. By contrast, after disconnection of the hippocampus from either its cortical or subcortical pathway, rats succeeded in acquiring the separate discrimination problems but did not demonstrate transitive inference, indicating that they had failed to develop or could not inferentially express the orderly organization of the stimulus elements. These findings strongly support the view that the hippocampus mediates a general declarative memory capacity in animals, as it does in humans.

Abstract: This study was designed to test the hypothesis that there is no significant difference in selected temporal and linear stride variables of the extended canter in horses bred and trained for dressage or racing. Nine advanced-level dressage horses and 7 Thoroughbred racehorses were filmed at a frame rate of 200 Hz at an extended canter on a sand track. Two strides were recorded per trial, and each horse performed 6 or 7 trials. Temporal and linear data were determined from the films, and descriptive statistics (mean, SD) were calculated. Strides were selected for analysis on the basis of having a velocity in the range of 6.0-7.0 m/s, and multivariate analysis of variance was used to detect significant differences in the stride kinematics of horses trained for the two sports (p < or = 0.01). The average velocity of the dressage horses was 6.37 m/s, compared with 6.40 m/s for the racehorses. There were no significant differences between the two groups in velocity, stride duration, stride length or the distances between limb placements. The stance durations of all four limbs and the overlaps between them were longer, whereas the duration of the suspension phase was shorter in the dressage horses than in the racehorses (p < or = 0.01). The time between impacts of the diagonal limb pair was close to zero in both groups, with individual horses showing some variability in the order of placement of the diagonal limb pair. However, the sequence of footfalls was not significantly different between the two groups (p < or = 0.01).

Abstract: “Clicker training” is a popularly promoted training method based on operant conditioning with the use of a secondary reinforcer (the clicker). While this method draws from theories of learning and is used widely, there has been little scientific investigation of its efficacy. We used 60 horses, Equus callabus, and assigned each horse to one of six reinforcement protocols. The reinforcement protocols involved combinations of reinforcers administered (primary versus secondary plus primary), schedule of reinforcement (continuous versus variable ratio), and reinforcers applied during extinction (none or secondary). There were no differences (P>=0.11) between horses which received a secondary reinforcer (click) followed by the primary reinforcer (food) and those which received only the primary reinforcer (food) in the number of trials required to train the horses to touch their noses to a plastic cone (operant response). There also were no differences (P>=0.12) between horses which received the secondary reinforcer plus primary reinforcer and those which received only the primary reinforcer in regards to the number of trials to extinction. We conclude that there is no difference in the amount of training required to learn the operant task or in the task's resistance to extinction between horses that received a secondary reinforcer followed by a primary reinforcer versus horses which received only a primary reinforcer.

Abstract: In order to determine if horses will increase their intake in response to caloric dilution, four pony geldings were fed ad lib a mixed grain diet either undiluted (3.4 Mcal/kg of digestible energy) or diluted (wt/wt) with 25% sawdust (2.6 Mcal/kg) or with 50% sawdust (1.7 Mcal/kg). The mean daily caloric intake was 17,457 kcal (3.4 Mcal diet), 17,546 kcal (2.6 Mcal diet) and 12,844 kcal (1.7 Mcal). The mean time spent eating was 246 (3.4 Mcal), 351 (2.6 Mcal), and 408 (1.7 Mcal) minutes/day. Meal size increased and meal frequency decreased with increasing dilution. The median long survivorships of intermeal intervals were 6.4 min (3.4 Mcal), 3.95 min (2.6 Mcal) and 4.91 min (1.7 Mcal). Ponies responded to caloric dilution by increasing the volume of intake to maintain caloric intake when the diet had 25% diluent. When the diet was diluted by 50%, intake was increased, but not at a rate adequate to maintain caloric intake. However, the ponies were able to maintain body weight.