With the arrival of cooler weather, it’s time to think about making wintertime adjustments to our horses’ diets. This is especially important for horses that are “hard keepers” and tend to lose weight in the colder months. Horses use around 25% more energy (or calories) in the winter. A variety of factors can affect the changes you make to your horse’s diet in preparation for winter, including environment, age, activity level, health status, and housing. Here are a few tips to make sure your horse is on track to receive the nutrients he needs to make it through winter.

Water

In winter adequate water intake helps prevent impaction colic, because it keeps feed moving through the digestive tract. When water sources get covered with a thick layer of ice or are extremely cold, horses tend to drink less than their required minimum of 1 gallon per 100 pounds of body weight daily.

Most forage in the winter is dry, so horses won’t receive moisture from grass like they do at other times of year. Therefore, ensure water is accessible and horses are hydrated. It is also important to have water available at feeding times.

Fiber

Increasing the amount of good-quality hay you feed can help your horse stay warm during the colder months. The anaerobic microbes in the horse’s hindgut digest the fiber in hay. This digestive process—mostly fermentation—produces heat that can help maintain core body temperature. Horses that don’t have to expend unnecessary calories on thermoregulation will have an easier time maintaining a healthy weight.

Have a good-quality forage available throughout the day. If feeding small square bales, you might need to increase the number of flakes fed per day compared to what you feed during the warmer months (a one- to three-flake increase daily is typically sufficient). If a stretch of especially cold temperatures is on the way, consider increasing the amount of forage even more and have it constantly available. Also, make sure the hay is in a location where it will stay dry.

Calories

Horses, especially hard keepers, require additional calories in winter. Cold temperatures, wind, and snow/wet conditions contribute to increased calorie expenditure. Increasing the forage content in the diet is a great way to increase calories. If increasing forage alone doesn’t maintain body weight, you can increase caloric intake by adding fat to the diet. Fats contain 2 to 2.5 times the calories per pound as the equivalent poundage of carbohydrates or proteins.

You can increase the diet’s fat content in a variety of ways, including top dressing a concentrate with oil, adding a fat supplement, or purchasing a feed with a higher fat percentage. Not all horses like the taste of fat additives, and it takes time for the digestive system to adjust, so it is important to introduce it to the horse gradually.

Feeding beet pulp is another way to increase calorie intake. Beet pulp has the benefit of providing increased fiber as well as calories. Additionally, if you soak the beet pulp before feeding, it can increase water intake.

Take-Home Message

Horses should always have access to good-quality water, but in winter we must pay extra attention to make sure they are drinking enough to stay hydrated and avoid impaction colic. Increasing hay intake can help horses stay warm through the fermentation process in the hindgut. Make sure the forage is good quality and has not been ruined by exposure to the elements prior to consumption. To help you horse maintain body weight without increasing the total “bulk” of the diet, you can add fat as a calorie source.