Abstract: Housing conditions for horses impose various levels of confinement, which may compromise welfare. Lying behaviour and activity can be used as welfare indicators for domestic animals and rebound behaviour suggests a build-up of motivation resulting from deprivation. The objective of this study was to determine if activity and lying behaviour of horses are affected by housing conditions and to investigate the occurrence of rebound behaviour after release from confinement. Eight horses were subjected, in pairs, to each of four experimental treatments; paddock (P), fully stabled (FS), partly stabled (PS) and yard (Y). Each horse received 6 days acclimatisation prior to the 24 h recording period. Time spent in lying and activity were electronically recorded using a tilt switch and motion sensor connected to a data logger worn on the horse's left foreleg. Time spent active during the first 5 min of release from stable to paddock in the PS treatment (days 1 and 5) and at the same time of day in the P treatment was used as a measure of rebound behaviour. Effect of housing conditions on total time spent active was highly significant (FS = 123 s, PS = 158 s, Y = 377 s, P = 779 s, P < 0.001). Housing conditions did not significantly affect total time spent lying (P = 0.646). Horses were significantly more active, compared with baseline paddock behaviour, on release from stabling on both days 1 (P = 0.006) and 5 (P = 0.025) of PS treatment. These results suggest that activity patterns of horses, but not lying behaviour, are affected by the housing conditions tested and that rebound activity occurs in horses after a period of confinement.

Abstract: Summary The aim of this study was to investigate the effect of gonadotrophin-releasing hormone (GnRH) immunisation on mature stallions that had been used for breeding. Four Standardbred stallions were used in the study: 3 experimental animals and 1 control animal. Semen was collected regularly, i.e. twice/week, during the 4 months prior to the experimental period. The stallions were immunised against GnRH with a GnRH-BSA conjugate. Equimune was used as the adjuvant. The stallions were immunised on 5 occasions, 4 at 2 week intervals, and the fifth 4 weeks after the fourth. Blood samples were taken once a week for analysis of GnRH antibody titre and every third week for testosterone and oestrone sulphate analyses. Semen was collected once a week, and libido and sexual behaviour were observed. Ejaculate volume, sperm concentration, total number of sperm in the ejaculate, sperm motility and sperm morphology were evaluated. Testicular size was measured once a week. At the end of the study, the stallions were castrated, and a histological examination of the testes performed. All immunised stallions produced antibodies against GnRH, and plasma testosterone concentration decreased. However, the effect of immunisation varied between stallions. In 2 of the stallions, high levels of antibodies were found, while in the third, the level was moderate. Four weeks after the first immunisation, a decrease in libido was observed. Two months after the first immunisation, marked changes in semen quality were observed in the 2 stallions with high antibody titres. Fourteen weeks after the first immunisation, the total number of sperm/ejaculate had decreased from >8.6×109 to<2.7×109, sperm motility from >59 to<10% and the frequency of morphological normal spermatozoa had decreased from >60 to<14%. The dominating abnormalities were abnormal head shapes, proximal cytoplasmic droplets and detached heads. In the third stallion, only slight changes in semen quality were found. No changes were observed in the control stallion. Decreases in testicular size were noted in all of the experimental stallions. Pronounced histological alterations in the testes were observed in 2 of the stallions. It is concluded that the vaccine was effective in stimulating production of GnRH antibodies and in suppressing testicular function and androgen secretion. However, there was an individual variation in the responses among the stallions and, further, libido was not totally suppressed.

Abstract: Summary The Ridden Horse Pain Ethogram (RHpE) comprises 24 behaviours, the majority of which are at least 10 times more likely to be seen in lame horses compared with non-lame horses. The observation of >=8/24 behaviours is likely to reflect the presence of musculoskeletal pain, although some lame horses score <8/24 behaviours. A marked reduction in RHpE scores after resolution of lameness using diagnostic anaesthesia proves a causal relationship between pain and RHpE scores. Horses should be assessed for approximately 10?min in walk, trot (including 10?m diameter circles), canter and transitions. The validity of the RHpE has been verified for use in horses which perform dressage-type movements, and which have been trained to work with the front of the head in a vertical position. It has not, as yet, been used in horses while jumping, racehorses, western performance or endurance horses. The RHpE provides a valuable tool for riders, trainers, veterinarians and other equine professionals to recognise the presence of musculoskeletal pain, even if overt lameness cannot be recognised. Riders with a higher skill-level may improve gait quality, but cannot obscure behavioural signs of pain, although specific behaviours may change. Tight saddle tree points, the rider sitting on the caudal third of the saddle and rider weight may influence RHpE scores. Accurate application of the RHpE requires training and practice. The RHpE is a powerful tool for the assessment of ridden horses and the identification of likely musculoskeletal pain. Such pain merits further investigation and treatment, to improve equine welfare and performance. The RHpE provides an additional means of evaluating the response to diagnostic anaesthesia. It provides a mechanism for client education and a diplomatic way of communicating with clients about equine discomfort related to saddle-fit, rider size, their position in the saddle and ability to ride in balance.

Abstract: Summary Domestication has provided the horse with food, shelter, veterinary care and protection, allowing individuals an increased chance of survival. However, the restriction of movement, limited breeding opportunities and a requirement to expend energy, for the benefit of another species, conflict with the evolutionary processes which shaped the behaviour of its predecessors. The behaviour of the horse is defined by its niche as a social prey species but many of the traits which ensured the survival of its ancestors are difficult to accommodate in the domestic environment. There has been a long association between horses and man and many features of equine behaviour suggest a predisposition to interspecific cooperation. However, the importance of dominance in human understanding of social systems has tended to overemphasise its importance in the human-horse relationship. The evolving horse-human relationship from predation to companionship, has resulted in serial conflicts of interest for equine and human participants. Only by understanding the nature and origin of these conflicts can ethologists encourage equine management practices which minimise deleterious effects on the behaviour of the horse.

Abstract: Little research has been done to measure reactivity objectively in therapeutic riding horses (TRH). As individual reactivity and chronic stress could be assessed by exposing animals to acute, novel stressors, the authors of this work aimed at comparing reactions of TRHs and jumping horses (JH) to two challenges. Four TRHs and four JHs were exposed to a restraint covering their head with a hood for 1 h and to a startling stimulus (a 40 cm long, red and white synthetic holiday garland shaken with a rustling noise inside the box). Heart rate (HR) and heart rate variability (HRV) were recorded continuously and telemetrically, the reaction was video-recorded and analysed with a software for behavioural analysis. Blood samples were collected before and after each challenge to determine lymphocyte proliferation and other biochemical parameters. Horses spent most of the time immobile, during the challenges (p < 0.05). TRHs had a significantly higher average basal HR than JH (p < 0.05), probably due to their better condition. HR varied among different behaviours during the restraint (p < 0.05): the average HR during “pawing” was higher than during other behaviours (p < 0.005). A significant decrease in the proliferation of lymphocytes in samples taken after the removal of the hood (p < 0.05) was found, while the other stress related parameters did not vary significantly after the challenges. The authors conclude that TRHs did not react less than JHs to the new stimuli and this should be taken into consideration while planning their daily work and management.