Linda Kjellberg

Background: Keeping horses in open barns has positive effects on social interaction and free movement, which may improve horse welfare. However, many horse owners fear that housing in open barns leads to more injuries.Objective: To compare health events among horses housed in an active open barn (AOB) or in single boxes (BOX).Study design: A prospective study during 9 months and a 2‐year retrospective study.Methods: Two housing systems in one farm were investigated: AOB and BOX in pairs or alone in paddock (2–4 h/day) using 66 and 69 horses in the prospective respectively retrospective study. Lameness, wounds, colic and days lost from training were recorded.Results: There were lower prevalences of lameness and colic in AOB than in BOX (18% vs. 26% and 0% vs. 5%; p < 0.001). Overall, there was a larger proportion of individuals with health events in AOB (83%) compared with BOX (52%) (p < 0.01). However, number of days lost to training did not differ between AOB (10 ± 15 days) and BOX (15 ± 34 days) (p = 0.36). There were no significant differences between the housing systems in number of health events/horse in the retrospective study: AOB 1.54 ± 1.51 versus BOX 1.14 ± 1.20 (p = 0.22).Main limitations: The different, not standardised, housing systems varied in size and number of horses with no individual consideration in this descriptive field study with no possibility to cross‐over. A convenience sample was used.Conclusions: Lameness and colic were less frequent in the AOB system compared to single boxes, probably because the horses in the open barn could move freely day and night. Horses in AOB had a higher prevalence of wounds due to interactions between horses, but this did not lead to more days lost from training.

Housing horses in open barns is becoming increasingly popular, with positive effects on social interaction and free movement that can improve horse welfare. However, many horse owners are concerned that group housing may lead to more injuries, less lying time and obesity. This thesis evaluated the effects of group housing horses an active open barn on behaviour and welfare in terms of health, rest and feeding. Horses at the Swedish National Equestrian Centre sites Strömsholm and Flyinge were studied. Health indicators such as lameness and colic were found to be lower for horses kept in the active open barn than in single boxes. Horses in the active open barn had a higher incidence of injuries due to kicks, but this did not lead to more days lost from training. Therefore, concerns about injuries in this system do not appear to be warranted. Comparisons of lying halls with different lying areas revealed that smaller lying halls led to shorter lying times compared with larger lying halls and single boxes. Greater available area in the lying hall also increased lying bouts and use of lying halls. Due to intra-individual variation, four measurements per horse were needed to establish a mean value for forage intake rate. ​​​​​​​In conclusion, keeping horses in an active open barn affects horse health and lying behaviour. Lameness and colic may decrease, probably due to free movement in the active open barn. To increase lying time among group-housed horses, the space requirement is likely to be larger, not smaller, than in individual boxes.

Sleep is crucial to horses’ wellbeing, and their lying time can vary according to such factors as climate, exercise, bedding, and housing. This study aimed to analyze behavior and time spent in lying halls of various sizes. We examined the influence of housing systems on total lying time and behavior, and how changes to available lying area can affect lying time. Two open barns were used in this study, with lying areas of 8, 15, and 18 m²/horse available in the lying halls. The horses’ behavior was video recorded and logged using scan sampling and interval observations. Individual boxes were used as a control. The horses were found to spend longer time in sternal and lateral recumbency in the hall with a lying area of 18 m²/horse than the hall with a lying area of 8 m²/horse. Increasing the area of the lying hall also increased overall time spent there. Consequently, the hypothesis that increasing lying area will increase the horses’ use of the lying hall, as well as their total lying time, was accepted.