Every season brings specific horse care challenges and winter is certainly no exception. Weather changes and forage availability are usually the major issues of concern for horse owners during winter months. These challenges are amplified when caring for senior horses, due to compromised ability to chew and digest hay, reduced ability to handle inclement weather and metabolic changes that occur with advancing age.
Respond to temperature changes
As the ambient temperatures get colder or when strong weather systems move through the area, horse owners take measures to keep horses warm and dry with proper shelter and blanketing when necessary. All warm-blooded animals have a critical temperature; the temperature below which an animal must produce additional heat to maintain normal body temperature. Mature horses in good flesh, where ribs cannot be seen, have a critical temperature around 30° F during early winter. After developing a winter coat and gaining 100 pounds, the critical temperature may be reduced to around 15° F. Young horses, old horses, horses in thinner condition and those that have been stabled and not developed a winter coat, may have a higher critical temperature around 40° F.
When wind or wet conditions are present, the critical temperatures will be higher as well. Horses require an estimated 15 to 20% more calories for each 10° F the ambient temperature falls below critical temperature. However, senior horses may need even greater increases in dietary intake to maintain normal body temperature.
Monitor hay quality and ingestion
Providing additional hay is a common way to increase calorie intake, helping horses stay warm and content. Access to more hay gives horses something to do while they are confined during bad weather. Also, digestion of fiber releases more internal heat than digestion of starch, sugars or fats, so hay serves as an internal furnace for the horse.
However, hay quality and availability during winter months can be a problem for horse owners. When hay is of lower quality, horses will voluntarily eat less of it, so they may not eat enough to meet increased energy demands during a long, cold winter. This is especially critical for aging horses with dental issues that compromise their ability to chew hay. Even when they can chew and eat hay, older horses often don’t digest hay as effectively as younger horses. In these situations, horses may have free-choice access to hay but still lose body condition.
Careful monitoring of body condition will indicate whether horses are taking in enough dietary energy to meet the demands of winter. Thick winter hair coats and blankets cover up horses’ ribs and topline so horse owners may not notice weight loss. It is important to routinely feel over the crest, withers, ribs, back and around the tail head to make sure horses aren’t losing body fat through the winter. When horses are eating all the hay they can eat and still losing weight, additional supplementation with more calorie-dense concentrate feeds is necessary to better support them through winter.
Hydration is not just a summer issue
When horses eat more hay, they should drink more water. Water consumption should be a minimum of 10 to 12 gallons per day for a 1000 lb. horse to support normal function of the digestive system and maintain adequate hydration. During weather changes and especially during extreme cold weather, horses often drink less water. When they eat more hay but drink less water they become at greater risk for impaction colic and reduced intake due to dehydration. To help encourage water intake, keep water sources clean, fresh and free from ice. A minimum water temperature of 45°F is a good goal for horses during harsh, cold weather.