Abstract: In both species of zebra, breeding males had higher urinary androgen concentrations (ng androgens/mg Cr) than did non-breeding bachelor males (30.0 +/- 5.0 (N = 9) versus 11.4 +/- 2.8, (N = 7) in the plains zebra; 19.0 +/- 2.2 (N = 17) versus 10.7 +/- 1.2 (N = 14) in the Grevy's zebra). In the more stable family structure of the plains zebra (single male non-territorial groups) variations in androgen concentrations could not be ascribed to any measured variable. In the Grevy's zebra, androgen values were significantly lower in samples taken from territorial (breeding) males which had temporarily abandoned their territories (N = 4) and the urinary androgen concentration for a male on his territory was negatively correlated with the time since females last visited the territory.

Abstract: We investigated 71 horses at five stud farms. Their breeds were Thoroughbred (n = 48), Anglo-Arab (n = 7), Thoroughbred mixed breed (n = 5), Appaloosa (n = 3), Selle Francais (n = 2), Dutch Warmblood, Haflinger, Pinto, Quarter Horse and Westfalen (n = 1, respectively), and one horse's breed was not known, but was a heavy horse. Their genders were stallion (n = 5), gelding (n = 41) and female (n = 25). Their ages ranged from 4 to 24 and the average was 11.1 +/- 5.3 (S.D.). The horses' behaviour was twice observed for 2 h both before and after feeding, using a scan sampling technique at 2 min intervals. We investigated the relationship between management factors, age, sex, breed and behavioural patterns of stabled horses, and the occurrence of weaving by a least-squares analysis of variance, a correlation analysis, Chi-square test and an analysis of behavioural sequences. Thoroughbred horses displayed weaving more than other breeds (P < 0.01) and horses in box stalls which were face to face with each other displayed weaving more than those in box stalls which were formed in a line (P < 0.01). The time budget of weaving correlated negatively with the amount of hay-cube fed (kg/day) (P < 0.05) and time budgets of drinking, bedding investigation, looking and coprophagia (P < 0.01, respectively). From the analysis of behavioural sequences, weaving followed resting (P < 0.01), looking (P < 0.01) and pawing (P < 0.05), and was followed by them (P < 0.01, P < 0.01 and P < 0.05, respectively). The least-squares analysis of variance revealed that Thoroughbred horses investigated the bedding more than other breeds (P < 0.05), horses that are usually in contact with `mainly familiar people' investigated the bedding significantly less than those usually in contact with `people including strangers' (P < 0.05), and horses in box stalls which were face to face with each other tended to investigate the bedding more than those in box stalls which were formed in a line. The time spent feeding was related to food type (min/kg), and tended to be negatively correlated with the time budget of bedding investigation behaviour. These results indicate that weaving in horses is affected by breed, stable design, feed type, and other behavioural traits.

Abstract: Mit der zunehmenden Bedeutung der Gruppenhaltung von Pferden ist die Tierärzteschaft gefordert mitzuhelfen, das Verletzungsrisiko in
Gruppenhaltungssystemen zu verringern. Dem Vermeiden von Schlag- und Bissverletzungen kommt hierbei eine zentrale Bedeutung zu. Präventive
Maßnahmen konzentrieren sich im Wesentlichen auf die Gruppenzusammensetzung und Eingliederung neuer Pferde sowie auf die
Gestaltung der Haltungssysteme. Die Raumaufteilung und die Fütterungstechnik müssen equidentypisches Verhalten (Lokomotion, langandauernde
Futteraufnahme und schadensfreie soziale Interaktionen) erlauben. Es gilt, Kenntnisse über Zusammenhänge zwischen Haltung,
Fütterung, Nutzung, Verhalten und Gesundheit an Pferdehalter und Stallbaufirmen weiterzugeben.
[Although group housing of horses has become common practice, the risk of equine injury is substantial. The veterinary community is challenged
to reduce this risk, particularly with regard to injuries caused by kicking and biting. Preventive measures should focus on the disposition
of horses within the group, the introduction of new horses to the group and the design of the housing facility. Feeding methods as
well as the structure of the environment should meet the physiological requirements for horses; there should be adequate space for exercise,
extended foraging and the possibility of benign social interactions. Veterinarians need to educate horse owners and builders of equine
facilities about the husbandry, feeding, use, behaviour and health of horses.]

Abstract: Public information is information about the quality of a patch that can be obtained by observing the foraging success of other individuals in that patch. I examine the influence of the use of public information on patch departure and foraging efficiency of group members. When groups depart a patch with the first individual to leave, the use of public information can prevent the underutilization of resource patches.

Abstract: Abstract Stress is a generic concept describing the body's reaction to external stimuli, including both physiological and psychological factors. Therefore, by definition, the assessment of psychological stress in the exercising horse encompasses the problem of teasing apart the psychological and physiological factors both of which result in stress responses. The present study reviews the existing literature on various measures of stress taken specifically in the context of equitation science. Particular attention has been paid to short-term effects, and commonly used measurements of short-term stress include heart rate, a number of heart rate variability parameters, blood or saliva cortisol levels, eye temperature, and various behaviour parameters including in particular behaviour patterns presumably indicative of conflict with the rider's/trainer's aids. Inspection of the individual studies' results revealed that disagreement between these different measures of stress is commonplace. For physiological parameters, the largest proportion of agreement (i.e. both parameters simultaneously indicated either higher, insignificant or lower stress compared to a control treatment) was found for heart rate and heart rate variability parameters, while generally limited agreement was found for cortisol. It appears that cortisol levels may not be particularly useful for assessing/assessment of the valence of a situation in the exercising horse as cortisol levels are predominantly linked to activation and exercise levels. Although heart rate variability parameters reflect in theory more closely sympathovagal balance compared to cortisol levels, great care has to be taken regarding the use of appropriate time-frames, appropriate raw data correction methods as well as the use of appropriate equipment. In spite of its wide-spread and apparently successful use, popular equipment may in fact not be accurate enough under field conditions. Eye temperature is another promising parameter for assessment of psychological stress, but the technique is likewise susceptible to application errors. Given the high susceptibility of physiological parameters to errors at various experimental stages, behavioural rather than physiological parameters may in fact provide more accurate measures of valence when conducting experiments in the exercising horse. Behavioural parameters that appear to be particularly practical in assessing stress in ridden horses' behaviour are associated with frequencies of behaviour indicative of conflict. However, while increased frequencies of are a good indicator of stress, the absence of conflict behaviour does not provide proof of the absence of stress due to the possible occurrence of conditions such as Learned Helplessness. In future studies, the above issues should be taken into consideration when designing experiments to assess psychological stress in ridden horses.