First, make certain the horses are in good body condition, at least a body condition score of 5 or 6, meaning that the horses are carrying some fat cover over their ribs. This is particularly important for older horses and pregnant mares. Winter hair coats can create the illusion of adequate body condition, so some hands on checking is in order. If broodmares lose body condition and are below a BCS of 5 at foaling, they may be more difficult to rebreed after they foal. Now is a good time to check body condition in case horses are losing weight due to weather and forage conditions.
Second, adequate water, preferably between 45 and 65 degrees Fahrenheit, should be available. Owners should not rely on horses eating snow for their water supply. A 1200-pound horse will require 12-15 gallons of water per day during cold weather. Having inadequate water available or water that is too cold for horses to drink comfortably may contribute to impaction colic. A horse that does not have adequate water available may also decrease feed intake, which may lead to loss of body condition. Horses that have to consume snow as a water source consume less water than desired and also use up a great deal of energy melting the snow as it is consumed. Salt should be available free choice, preferably loose salt rather than a salt block during cold weather.
Third, adjust feeding according to temperature and body condition. A horse’s energy requirement increases about 0.7% for each degree the air temperature is below 18 degrees Fahrenheit, depending on the horse’s hair coat and body condition. Wind chill increases the energy requirement also. Hay or high fiber products produce more heat during digestion than do straight cereal grains, so adding extra roughage to the diet is a good option. Grain intake can also be adjusted to maintain the desired body condition, but needs to be adjusted gradually. Sudden increases in grain intake due to changes in temperature should be avoided.
Proper winter care and feeding will help assure that the horses are ready for spring when it finally arrives!