For the last four years, I have had my horses living on my land in a run-in shed year round. This included winter weather. I am now down to one mare that is in good condition and spending her time out.
In winter, as the weather gets colder, I increase her feed, oats, to double,as keeping a good body weight is important to fuel body heat and she gets all the haylage she can eat.Link for feeding info Fresh water is supplied daily. She has a natural hair coat, which I do not clip to help her keep body heat. Her days are spent standing at the top of the field, looking over to the neighbors as they are building a new house. She goes into her shed to eat her hay and rest. She also has access to natural field with bushes, fir trees, a pond and four inches of un-eaten grass from summer. Wintering out helps to keep them healthier because they breathe fresh air and can adjust to the temperature changes on a regular basis. It also encourage lots of movement and exercise to keep warm; this is how horses keep warm in the wild.
Things to remember when wintering out-
1-If your horse is wintering outdoors in a temperate winter climate is careful of rain. Wet cold is far less tolerable than dry cold, and as well as ensuring that there is access to some form of shelter such as a shed, to allow the horse to get out of the elements.
2-Clean out your horse's hooves well. Add a layer of non-stick cooking spray or petroleum jelly to your horse's hooves; this will prevent balls of ice and snow from forming in the hooves.
3-Groom your horse. A dandy brush and short curry comb is best. This is not only good for warming the horse's muscles, but serves as an excellent warm-up workout for you too.
4- If your riding, take care about where you choose to ride. Pitfalls for riding during winter are varied depending on whether you're riding in snow or in more temperate muddy, cold temperatures. Things to watch out for include:
•Deep snow, especially where it conceals holes, tree wells, and crevices where your horse could slip down.
•Ice. Any ice is potentially dangerous as your horse has no grip or traction.
•Mud. While a little mud is fine, a lot of mud can cause the horse to become bogged, or to trip. Mud can also conceal objects that might harm your horse. Large areas of mud are best avoided.
•Wet slopes. Take care riding a horse down a wet slope, as it is easy to lose grip, especially when going fast, and moving over wet stony or rocky areas.
•Never canter or gallop your horse in snowy, muddy, icy, or slick terrain.
If your horse is kept inside all winter be aware of possible winter ills. Just like us, horses get sick during winter and it's important to know what to be on the lookout for, and how to manage the problems that human intervention can cause.
•Horses are susceptible to respiratory illnesses during winter. The ammonia build-up, mold, and dust inside barns and stables can bring on a variety of respiratory illnesses. Do your best to prevent this by ensuring adequate ventilation and giving your horse plenty of outdoor opportunities to breathe in fresh air. Clean out stalls regularly.
•Horses are also susceptible to skin conditions during winter, such as rain-rot, bed itch, ringworm, lice, and infected scratches. Keep the horse clean, groomed, and medicated appropriately. Be careful not to blanket a wet horse or to use blankets that do not breathe but cause moisture build-up. See your vet promptly for treatment of skin ailments.