First, horses acclimate to cold weather by developing fatty tissue that “winterizes” them. Even in cold weather, horses usually prefer to be outdoors. If the horse is in good physical condition with a good body-fat ratio, it will be fine.
A long winter hair coat serves as insulation by reducing the loss of body heat and provides the first line of defense against the cold. When the horse becomes wet and/or covered with mud or snow, the winter hair coat’s insulating value is reduced. This is why it is important to provide regular grooming and windbreaks or shelter.
Natural windbreaks such as tree lines or shrubs can be very useful. The last thing you want to do is put an animal that is acclimated to the cold weather in a heated environment.
An increase in body metabolism through various physiological mechanisms helps horses maintain body temperature. To conserve central body core temperatures, the thyroid gland produces the hormone thyroxin to increase metabolic rate and provide warmth. Couple this with bacterial fermentation of forage in the hind gut and the horse can generate a tremendous amount of heat. Horses can tolerate much colder weather by having sufficient, good forages throughout the winter.
To maximize this additional warmth from the consumption of hay or winter forage, Jennie Ivey, University of Tennessee Extension equine specialist, says a horse should consume 1.5 percent to 2 percent of their body weight of good quality hay/forage per day. For example, a 1,000-pound horse will eat 15 to 20 pounds of hay daily.
It is recommended to have your hay analyzed and develop the rest of the ration based on the hay quality. Look for hay that smells clean, has fine stems and lots of leaves, has minimal seed heads or blossoms, and is not damp or weedy. Contact your County Extension office to have your hay tested. Don’t buy a “pig in a poke.” It is better to find out for sure.
The energy requirement to maintain a horse on a daily basis also increases during cold weather. For every degree below the lower critical threshold temperature, energy requirements increase by about 10 percent. We usually talk about 25 percent increase during very cold winter periods. Pay close attention to the horse’s body condition score during winter to make sure the diet is meeting the energy needs of the horse. The lower the body condition score, the more the horse needs additional attention during cold periods. The lower the body condition score the more the horse needs adequate shelter.
Ready access to water is extremely important. Pay special attention to water sources becoming frozen. Horses should consume 5-10 gallons of water per day. In cold winter situations, difficulties arise in providing water that is too cold or in a semi-frozen state. Horse owners have discovered that warming the drinking water for their horse during the winter will lead to the horse consuming more water. If horses don’t drink water, they can’t eat dry food to get the energy needed to produce body heat. Water deprivation can cause cold stress, colic and abdominal distress in horses.
Show horses with hair coats that are artificially short should not be turned outside in bitter winter cold without a blanket or windbreak. If a horse is housed in a barn during most of the winter, the barn should be adequately ventilated to reduce the risk of respiratory disease. Proper ventilation eliminates excess moisture and condensation buildup.
Be vigilant of signs of cold stress, which include huddling together, seeking shelter and shivering. Foals will curl up to minimize body surface area. Loss of body condition could be a sign of inadequate nutrition and should be a clue to increase hay/forage and provide additional energy sources and more shelter.
For additional information on these and other topics, contact the UT Extension Office, 925 East Baddour Parkway, Lebanon, TN 37087, 615-444-9584 or firstname.lastname@example.org. UT Extension provides equal opportunities in all programs. Visit the UT/TSU Extension webpage at utextension.tennessee.edu/wilson or look for UT & TSU Extension, Wilson County on Facebook.