Loose Housing of Horses in a Cold Climate Effects on Behaviour, Nutrition, Growth and Cold Resistance

Housing of weanling horses in cold loose housing systems is common in the Nordic countries, although its suitability as a winter environment has not been studied. This thesis aimed to study the effects of a cold loose housing environment on weanling horses. The loose housing system consisted of insulated halls with a deep-litter bed, entrance shelters and paddocks to which the group-housed horses had free access. The effects on the behaviour, nutrition, growth and cold resistance of the horses were studied. The time budget of the horses consisted mainly of eating, resting and standing (37, 32, and 26 % of daily time, respectively); only one hour (5 %) was spent on locomotor activity. Their circadian rhythm largely resembled that of feral horses. The horses acclimatized to the cold by behavioural, metabolic and insulation adjustments. Their activity was low and huddling existed commonly. Energy intake increased by 1.8, 0.5 and 0.2 % in November, December and January, respectively, per 1 °C decrease in ambient temperature below the lower critical temperature of –11 oC. When this demand was taken into account in the feeding, the horses gained weight at expected rates. The results for radiative heat loss and winter coat development indicated that differences existed in the cold resistance of the horses, coldblood and pony types being more resistant than light and warmblood types. A loose housing system contributes to horse welfare by allowing horses to follow the natural circadian rhythm of behavioural patterns, but does not necessarily encourage activity. The opportunity to behave unrestrictedly rather than the opportunity for high locomotor activity seems to be more important for horses. Weanling horses cope in the cold and thus can be reared in loose housing systems provided their level of acclimatization is taken into account in the feeding and that the loose housing facilities are adequate. However, due to changing animaland environment-related factors during the winter and ad libitum forage feeding, the regulation of nutrient intake is complicated and the risk of overfeeding and imbalanced nutrition is high in late winter. With regard to horse welfare, this thesis indicates that loose housing may involve both advantages and disadvantages. The suitability of loose housing for weanling horses depends on which welfare-related features are emphasized. Universal Decimal Classification: 591.615, 599.723.2, 636.083.312, 636.1 CAB Thesaurus: animal housing; loose housing; cold zones; horses; animal welfare; thermoregulation; acclimatization; animal behaviour; animal nutrition; circadian rhythm; energy intake; growth; cold resistance; heat loss; thermography