Having adequate shelter is an important building block in any pig operation. A place to get out of the elements is conducive to acquiring and maintaining good health amongst your herd. There are a variety of shelter types that will work for pigs but the fundamentals of each remain the same.
For starters, pig shelters need to be sturdy enough to contain pigs and should be built of materials such as wood or blocks. The last thing you want is to spend all your time and effort on building a secure fence just to have your shelter be a failure point through which your pigs are able to escape, which can happen if you use your shelter as a cornerstone in a containment area. Having a sturdy shelter can be tricky because certain building elements can create problems for pigs. For example, if the floor of the structure is made of concrete, hoof and joint injuries can occur due to the hardness of such flooring. To prevent such injuries, dirt flooring is best, but if concrete must be used, be sure to pad it six inches or so of bedding. When it comes to bedding selection, several options exist. Pigs love building nests to sleep in and seem to be especially fond of straw. If you choose to use straw, make sure that it is clean, dry, and plentiful with soiled straw being removed on a daily basis. Also acceptable for use are wood shavings. Rubber mats can be used as well but these present cleaning difficulties that you may wish to avoid.
The next thing you need to arrange in your shelter is good ventilation. Since pigs are unable to sweat, air flow will aid in keeping them cool when it becomes hot. Proper ventilation will also aid in keeping the area dry which is imperative since wet/humid conditions can lead to pneumonia, yeast growth on skin, and other skin ailments. Adding fans is another way to keep the air moving in a shelter and keep pigs cool at the same time. In some cases, seasonal amendments may be necessary to keep pigs comfortable, such as adding extra wind barriers or deflecting heat from metal roofs.
Shelter size is important as well, and the size of your shelter should be relative to the number of pigs you plan to house inside. A shelter too larger for the number of pigs it contains will be hard to keep warm, and likewise, one that is too small will be hard to keep cool. Just as you do not want pigs to overheat, they need to be kept from getting too cold as well. Insulating the shelter can help with this; insulation can be added to the roof or inside of block walls. Thermal mass can be utilized as well as heat lamps but lamps do pose a fire danger and should be used at your own discretion with full understanding of associated risks. All told, the best option is a draft-free barn filled with straw and enough pig bodies to warm it naturally, but if you do need to supplement heat, consider radiant heat, which poses far less fire risk than other options but can be pricey.
When all is said and done, a well-built pig shelter than does the job you need it do to is priceless. Even though some components may be costly or require extra effort on your part, the health and safety of your pigs supersedes that, and in truth we probably wouldn't have it any other way.