According to SmartPak, your horse’s coat may be smarter than you think! Because your horse was designed to spend his days roaming outside, he is naturally equipped with tools to keep himself warm when the temperatures start cooling down.
Horse in a winter blanket
Horses naturally spend winter days roaming outside and are equipped to stay warm when temperatures are cold, but that doesn't mean he will not benefit from a carefully chosen blanket.
In response to the fading sunlight, your horse’s body starts producing his winter coat as soon as the days start getting shorter. He begins to grow his longer, thicker winter coat in July, shedding the shorter, thinner summer coat in October.
That winter coat has longer and coarser hairs than his summer coat, and he uses them to keep himself warm by fluffing them up to trap heat. The individual hairs stand up rather than lying flat against the skin, which traps warm air close to his body and insulates him from the cold.
Along with using this thick hair coat to stay warm from the outside, your horse also uses calories to keep himself warm from the inside. His body ferments roughage in the hindgut, which creates heat that helps maintain his core temperature, which is why many horse owners feed more hay in the winter.
However, even your horse’s full winter coat and normal calorie intake may not be enough to keep him warm all winter, depending on his body’s lower critical temperature or LCT.
Your horse’s lower critical temperature is the lowest temperature at which he can maintain his core body temperature without using additional energy. Once the temperature outside gets below that lower critical temperature, his hair coat and normal calorie intake alone aren’t enough to keep him warm.
The lower critical temperature of an individual horse will depend on the temperatures that he’s accustomed to, the amount of body insulation he has such as the length of his hair coat and the amount of body fat, and whether he lives inside or outside. That’s why even horses with a full winter coat can sometimes benefit from a blanket!