How to Winterize Your Horse

Although horses are very adaptable to cold, winter weather, they need to be managed. To understand the impact on the horse in winter we need to understand the heat (energy) balance. Heat or energy balanced is the difference between heat loss and heat gain over time. If the heat loss is greater than the heat gained the horse will lose weight, but if the heat gained is greater than the heat lost then the horse will gain weight. Horses will lose heat to the environment whenever air temperature is colder than the horse. A horses skin temperature is about 85° F. The colder the air around the horse the greater the heat loss will be. The main source of energy or heat gain is calories (since they convert into heat) obtained from feed. Horses exposed to constant cold weather become accustomed to the cold. Usually, horses require 10-21 days to adapt to cold. For example, horses kept at 75°F and exposed to 50°F will adapt to temperatures of 50°F over 10-21 days. If the temperature drops below 50°F then it will take another 10-21 days for them to adapt. The factor that relates to the adaption to cold is the energy intake. Horses lose weight if they do not consume enough energy to offset  the heat loss in the surrounding air. Well fed horses adapt to the cold without a problem. Unfed horses will lose weight and lose cold tolerance. Maintenance energy intakes of adult horses must be increased 1% per degree below temperatures of 5°F. Horses can be fed hay free-choice without fear of founder (just no sudden changes in hay quality/type). However, owners who are limit-feeding their horses should insure that they increase feed 1% more feed per degree below 5°F. Salt and mineral should be also provided. Clean fresh water should always be available to horses and snow is not a good substitute. A horse will have to consume ten times its water requirement in snow to meet their needs. This is a huge energy drain  and when coupled with poorly digestiuble hay, can lead to impaction (colic). Winter pastures should not be relied on to be the sole sourse of nutrients for horses. Not only is the nutrient quality poor but in deep snow the maintenance energy needs of a horse can increase by 40% since the horse has to paw to find grass. The cost of weight loss in the horse is much higher than most people realize. Thin, undernourished stallions loose ability to produce sperm, thin mares decrease their conception rate, and underfed weanlings can be permanently stunted. The extra cost of feed needed to rehabilitate a thin horse back to normal weight will exceed the cost of feed that should have been given to the horse to maintain. Feeding horses is costly; not feeding horses is more costly.