Regulating barn temperature and barn humity levels will help protect horse health during the winter months.
Horse owners who use heated barns to keep water from freezing and to protect horses from cold temperatures during winter should remember supplemental heat can cause problems if used incorrectly.
Ventilation is important when horses are kept inside a barn, says Dave Freeman, Oklahoma State University Cooperative Extension equine specialist.
“Closing up a barn to maintain heat may increase respiratory illnesses because of high ammonia content and bacterial growth in stalls,” he says.
Closed barns usually have increased humidity. High humidity combined with warm temperature can cause enough ammonia smell or bacteria growth to irritate the horse’s respiratory system. These frequently result in chronic, minor respiratory illnesses that interfere with the horse’s performance.
Freeman says controlled research to define acceptable humidity and temperature levels to lessen the chance of respiratory illnesses is difficult because of the variability between barns, the horses’ daily routines in and out of the barn, and the lack of controlling research conditions. However, many veterinarians attest to an increase in horse respiratory illnesses in heated barns with high humidity.
“The solution is to turn down the heat and get rid of the humidity by increasing air flow,” Freeman says.
Some farm operators have reported beneficial results by installing exhaust fans that move air when the barn humidity rises. It’s possible to make these systems automatic by installing rheostats that respond to barn humidity levels.
Another problem is that while the ideal temperature for horses is 45 to 65 degrees F, this “ideal range” may be neither cost effective nor a way to promote horse health.
“Increasing the heat of a barn above 55 degrees F not only can be expensive, it also may have negative effects when moving horses out of the barn into colder temperatures,” Freeman says.
Horse managers also need to remember that horses under artificial-lighting programs for reproductive or show reasons will shed hair. Therefore, special considerations must be given to protect horses from cold, windy and wet weather.
Even though hair growth is largely a photoperiodic response, warm environments assist in keeping hair short. Adequate hair cover is extremely important in cold conditions, providing the horse with needed insulation to combat the cold stress of near-freezing or freezing temperatures. Frequent movement into and out of heated barns from cold outside environments may in itself be a significant source of stress that can be avoided.
Freeman says one alternative is to maintain barn temperatures at around 45 to 55 degrees F and use blankets to keep horses with short-hair coats protected from cold temperatures in and outside of the barn.
“Part of the problem with maintaining proper barn temperature is that people working in the barn often like it a bit warmer than is recommended for the horses,” he says. “Horse managers should maintain barn temperatures at a level that will help promote healthy horses and not at a level dictated by a worker’s personal comfort.”
This might require periodic checks by the barn manager to ensure barn temperatures are set at the proper level.
“It’s often just a case of human nature. If you’re cold, you don’t think twice about turning up the heat a bit,” Freeman says. “But that oversight can cause health-related problems for horses, which in turn can mean money lost to the horse owner.”