So, it's essential to provide him with protection in the form of weatherproof blankets and shelter from the elements when he's outside. So is a diet that will provide your horse with the fuel to keep his internal temperature at a comfortable level. Given the chance, horses will lay down an insulating layer of fat under the skin in the fall, as part of their winter survival strategy. Therefore, altering your feeding program for the upcoming winter by providing some extra calories will go a long way toward helping your horse brace himself for the bitter winds. Although you might want him in fighting trim during the summer months, it's okay to let him put on a few pounds come autumn, particularly if his performance schedule is winding down for the year.
Horses have to work harder to maintain their internal body temperature when the thermometer plunges.
By contrast, grain, which is digested in the small intestine, is easier for the horse's system to break down, so it creates less heat. This is one instance when you might want to seek out hay with a slightly higher legume content than grass, even for your mature horses. Although your horse's protein requirements don't increase in the winter months, higher-protein legume hays are also higher in energy and nutrients, and that bit of extra energy might be a boon when temperatures plunge. When you consider increasing the amount of forage your horse eats in the winter, remember that his pasture will likely no longer be providing any useful contribution to his diet. If it's not covered in snow, the grass there will be dead or dormant, with practically no nutritional value.