We're having a lovely warm autumn here in Wisconsin. November is usually one of my least favorite months with cold, wind and wet weather making work outside miserable. We're getting a reprieve this year, though. I moved the electronet yesterday and didn't have to drill any post holes. The hoses aren't even frozen yet. However, as soon as I send off this article no doubt all will change. In most of the sheep raising parts of the country, winters are cold and snowy. While this may be a problem for shepherds, the sheep tolerate winter conditions quite well. There is no need to house wooled sheep indoors during the cold winter months. I repeat, there is no need to house wooled sheep indoors during the winter!
Sheep have some very effective ways of keeping warm. Their wool insulates them, holding in body heat and resisting the penetration of water. Those of you in snowy climates have seen sheep with a fresh layer of snow on their backs. The reason it doesn't melt right away is because the body heat is kept in by the fleece. In addition, the process of rumination, with its fermentation of fibrous materials, generates a great deal of heat. The more forage a ruminant eats, the more heat its body produces. Pregnant ewes, in which growth of the fetus results in heat production, stay even warmer as their pregnancy progresses. In fact, ewes carrying multiple fetuses have to increase their respiratory rate just to get rid of body heat. This is one of the reasons they benefit from shearing during the last six weeks of gestation.
Keeping sheep outside during the winter benefits both the sheep and the shepherd. The sheep benefit from better ventilation and increased exercise. Most of the cases of respiratory disease that I treat in sheep occur in animals that are housed in a barn during cold weather. The cause is the build-up of moisture and ammonia in the air. The ammonia damages the lining of the respiratory tract, interfering with its resistance to infection, and the stale moist air transmits viruses and bacteria into the airways. This combination of factors leads to coughing, sinus infections, bronchitis and pneumonia. Just like kids in a daycare, when one gets sick the infection is easily spread to the rest of the group. Sheep that live outdoors breath fresh drier air and are not exposed to ammonia fumes. Bronchitis and pneumonia in these animals is rare. The major benefit to the shepherd, besides having fewer sick sheep, is not having to clean the barn. This saves time and energy, both of which are generally at a premium on the farms I visit.
In my part of the country the most common type of livestock housing is an old style dairy barn, called a bank barn. Hay is stored above and livestock kept below in the dark damp basement portion. While they can be modified for improved ventilation, it is my opinion that animals should not be kept in these pneumonia dens. The only ones I have seen that could be safely used have had windows and doors removed, ventilation holes cut up to the loft area, and added exhaust fans to pull out warm moist air. The sheep were sheared to help keep them dry and the pens were bedded heavily and cleaned often. Whatever you do, don't close these barns up to try to make them warm. The animals will suffer.
I have to admit that it is possible to design sheep housing that has good ventilation. The lambing barns in Scotland, where cold wet weather is the rule in late winter and early spring (not to mention the rest of the year), have solid sides up to four or five feet, then slatted walls the rest of the way up to a very high roof with an open ridge. The ends are left open. There is lots of air flow and the sheep are bedded heavily in straw to keep them dry. Wind, rain and snow still enter the barn, but at sheep level it is dry and not drafty. If I could, I would have a barn like this. However, my small flock would not justify the cost.
Flocks kept outside during the winter have a few special needs. These include shelter from the wind, proper nutrition and water. During storms, they need access to a windbreak. Shelter need not be fancy. It can be a tree line, the down wind side of a hill, a row of round bales, or the side of a building. On very cold calm nights the sheep will bed down comfortably but their long wool may become frozen to the ground by morning. Smaller sheep may need help getting up.
The key to keeping sheep healthy during the winter is proper nutrition. If they have adequate forage they will stay warm. We have had good success self-feeding large round bales. They are put on a clean piece of ground and surrounded with cattle panels to prevent the sheep from sleeping in the feed. Grass hay, corn stalks and straw can all be balanced with appropriate supplements of alfalfa or grain to provide a complete diet. Trace mineralized salt should be provided free choice at all times.
Sheep readily eat snow to meet their water needs. However, if the snow is covered with a layer of ice or clean snow is not present, water must be provided. Sheep may be watered once a day, but be sure that they all have an opportunity to drink. Sometimes it's easier to take the sheep to the water than to take the water to the sheep, particularly if you use herding dogs. Lactating ewes need to have water available at all times.
There are two situations during which a flock may need to be housed temporarily. These are during the first ten days after shearing and at lambing. If the flock is shorn during below freezing temperatures or if a storm hits immediately following shearing then shelter should be provided. After ten days the ewes' metabolism has adjusted and, given adequate food, they will be fine without shelter. A barn, hay shed, machine shed or garage can be used temporarily if necessary.
While adult sheep can handle severe cold and wet quite well, newborn lambs cannot. Hypothermia occurs rapidly during windy wet weather, even if the temperature is not extremely cold. Severely cold temperatures can freeze the lambs before they have a chance to nurse. Neonatal lambs need to be kept dry and out of drafts. Cold dry temperatures are not a problem after they have a belly full of colostrum. However, the combination of wet and wind can kill even a two week old lamb if shelter is not provided. Something as simple as tarps set up over lambing pens can save pasture born lambs during an unexpected spring storm. If emergency shelter is not available then plan your lambing to occur later in the spring during warm weather.
If you lamb indoors in the winter, bring inside only the ewes that are due to lamb within the next week. This prevents overcrowding and keeps the humidity down. Remember not to close up the barn but to provide plenty of ventilation, even it you have to add layers of clothing. If you are comfortable then it's probably too warm for the sheep!