Time Budgets in Domesticated Male Icelandic Horses on Pasture Turnout in Winter and Spring

There are few 24 h time budgets for horses, especially for domesticated horses kept at pasture. Most time budgets utilise short-term scan sampling, which can miss behaviours. This study aimed to assess the seasonal variation in continuous behaviour of domesticated Icelandic horses at pasture during winter and spring in fair weather. Eight Icelandic horses (11.25 ± 9.19 years; 7 geldings, 1 stallion) were observed in a 26 acre field. Herd location and individual behaviour were continuously observed during 3 h periods amounting to 3 × 24 h in winter and late spring, compiled over 43 days (~21 days per season). Seasonal variation in behaviour (ANOVA), body condition (RMANOVA), and age-group variation (independent <i>t</i>-test) were assessed, as well as associations between weather, time period, and habitat choice (chi-square). During spring, horses showed more foraging (+18%; <i>p</i> < 0.001), movement (+0.5%; <i>p</i> < 0.05), recumbency (+5.7%; <i>p</i> < 0.01) and less standing (-24.6%; <i>p</i> < 0.001) than in winter. Behavioural synchronicity occurred between adult and juvenile horses. Mean body condition reduced from 5.6 to 4.8 in the winter. Habitat preferences varied by daytime and season, and non-feeding periods lasted less than 2 h. The 24 h foraging activity (winter: 12.7 ± 0.4 h, spring: 17 ± 0.25 h) supported the current recommendation of 12 h/24 h for domesticated horses to meet ethological requirements.