As the days get shorter and the holiday decorations fill the aisles at stores, people start to think about preparing for winter horse-keeping. The good news is that horses are better adapted to handling cold temperatures over excessively high temperatures. In fact, the temperature at which horses begin to expend extra energy to keep themselves warm is much lower than the temperature that most people begin to layer on coats.
How Horses Maintain Their Body Temperature During the Winter
The temperature that horses begin to expend extra energy to maintain their optimal internal temperature is called the Lower Critical Temperature (LCT). This value is dependent on body condition, hair coat, wetness, and wind chill. A horse in good body condition with a dry winter coat has a LCT of 18°F, while a horse with a wet coat or a thin coat needs to expend energy to maintain their internal temperature at 59°F.
A horse's coat offers considerable insulation, and its impact is something to keep in mind when blanketing horses with a full or partial body clip. Wind chill will significantly decrease the Effective Ambient Temperature, or the “feels like” temperature, and should be accounted for when determining the impact of winter weather on a horse’s nutrient requirements if they are outside. This is particularly true for those horses that choose not to use the shelter provided!
As temperatures drop, horses maintain body temperature through behaviors such as huddling together and positioning their body with tail toward the wind, as well as through physiological changes. During cold weather, hair stands on end to create insulation, blood flow to extremities is decreased to maintain core body temperature and the horse’s metabolic rate goes up to generate heat. In extreme cold, the horse will shiver to create body heat; however, this is a very energy expensive way for the horse to maintain body temperature and should be avoided.
Helping Horses Thrive During the Cold Winter Months
Whether your winter is cold and rainy, or you rarely see a day above freezing, it requires a combination of management and feeding practices to keep horses in good body condition over the winter. From a management perspective, keeping horses dry and out of the wind is extremely important and will dramatically increase their ability to handle cold weather.
Setting horses up to maintain body weight throughout the winter starts with ensuring horses enter the winter in good body condition. This can be challenging, as pasture in most parts of the country is declining throughout the fall, both in the quantity available and the quality of the forage. Keeping a close eye on body condition and pasture condition through the fall and supplementing declining pasture with hay before major body condition losses helps prevent situations where we are attempting to add weight going into winter.
On the other hand, trying to pack on the pounds so a horse goes into winter with extra body condition is not necessarily a healthy approach. Many horses, particularly as they age, are at risk for the development of metabolic conditions, and excess body weight (BCS 7+) has been linked to higher risk of development of insulin resistance and laminitis. So, instead, look to achieve a healthy body condition (BCS 5-6) going into winter and feeding and managing to maintain.
What to Feed During the Winter to Help Your Horse Stay Warm
It is a common misconception that “hotter” feeds, like oats or corn, generate more internal heat and are, therefore, a good addition to the horse’s diet in the winter. Quite the opposite is true; relatively little heat is produced digesting corn, oats and other cereal grains. A significant amount of heat is produced through fermentation of fiber in the horse's hindgut. Increasing forage availability during the winter is a better way to help horses maintain their body temperature without major calorie cost. As a bonus, forage is a better choice for maintaining digestive health!
Providing additional forage, particularly as temperatures dip below freezing, will assist in offsetting the additional energy required for temperature maintenance. If additional forage is not an option, a feed high in digestible fiber can be a good option. Look for feeds with ingredients such as beet pulp, soy hulls and alfalfa. For the harder keeper, a high fat feed or fat supplement is a good addition to high quality forage to maintain weight without overfeeding horse feeds.
Finally, no winter-feeding article would be complete without mentioning water! Horses require a source of clean, easily accessible water at all times. Although horses will eat snow in the wild to meet part of their water needs, a horse cannot consume enough snow to meet their water requirements. Horses prefer water to be warmed to 45°F and will increase water intake accordingly. Consistent water intake throughout winter is key for maintaining digestive function and decreasing colic risk.
Additional Resources Available
We have other articles that can help you prepare your horses for the cold months of the year. They are well worth a read and can be found by clicking on the following links:
- Supporting Your Horse During Seasonal Changes
- How Your Pastures Change in the Fall
- Preparing for Winter: Hay
- Preparing Your Senior Horse for Winter
- Calorie Requirements During the Winter
- Winter Forages
If you find yourself needing expert advice in preparing your horses for the winter months, or you need any information on any nutrition-related topics, feel free to reach out for a free consultation to ensure your feeding program is meeting your horse’s needs.