Keeping Horses Comfortable in Winter Temperatures by: University of Minnesota Extension January 30 2008, Article # 11246 http://www.thehorse.com/ViewArticle.aspx?ID=11246&WT.mc_id=news However, horses should have access to shelter from wind, sleet, and storms. Easy access to a stable or open-sided shed works well, as do trees if a building is not available. In the absence of wind and moisture, horses, acclimated to the extreme cold can tolerate temperatures near 5°. If horses have access to a shelter, they can tolerate temperatures as low as 40° below zero. However, horses are most comfortable at temperatures between 18° if the horse has a winter coat and 59° if the horse has a summer or wet coat, Hathaway said. Keep in mind that a horse’s winter coat can be an excellent insulator, but its insulating value is lost if it gets wet, so it is important to keep the horse dry and sheltered from moisture. Blanketing the horse is beneficial when the wind-chill and/or temperature is less than comfortable. Hathaway encouraged horse owners who house their horses in closed and heated stables to make sure they are properly ventilated. Poorly ventilated barns can result in respiratory problems. In terms of feeding, energy needs for maintenance of horses increase 1.4% for each degree of temperature below 18°. Hathaway advised it is best to provide the extra energy as forage (hay). For example, if the temperature is zero, a 1,000-pound idle, adult horse would need an additional four pounds of forage each day. Ideally, forage would be provided on a free choice basis so the horse could eat what it needed. Much more heat is produced when forages are fermented, which helps heat the horse from the inside, compared to the digestion and absorption of grains. Most data suggest that the need for other nutrients do not change during cold weather. Water should be kept at 45-65° (use of a tank heater, etc.) to maximize water consumption. Waters should be cleaned regularly (even in the winter), and clean, fresh water should always be available, regardless of temperature. .