Raising Pastured Pigs in the Winter
This article originally appeared in the winter 2024 issue of the Organic Broadcaster, a quarterly publication produced by Marbleseed, a non-profit dedicated to supporting organic + regenerative farmers.
Livestock producers in a four-season climate must contend with unpredictable and at times extreme weather. Keeping animals comfortable in inclement conditions is important for their health and productivity. As a pastured swine producer in the upper Midwest, it is essential to have a system in place to protect our herd from both the muggy days of summer and the frigid days of winter. As average temperatures continue to drop in northern latitudes, it is an ideal time to review our strategies for maintaining a healthy herd through the winter months.
For our first four years of swine production, we purchased feeder pigs in the spring and butchered in the fall. There were some advantages to this model: no worries about drinking water freezing, less investment in bedding and shelters, and (if one got up early enough) generally more pleasant weather for daily chores. However, our farm also grows produce for farmers’ markets and wholesale; and that means we were operating two concurrent enterprises for half of the year without any significant agricultural enterprises for the other half. One method to develop a more balanced workload was to begin raising pigs year-round.
For those raising pigs in the winter, there are two main scenarios; the first is to purchase feeder pigs in the summer/fall and butcher in the winter/spring. The second scenario is a farrow-finish operation, in which case you will likely be caring for both mature breeders as well as feeder pigs year-round. We added a boar and two sows to our pig operation this summer, so we have 3 adult breeders and 9 feeders until February when the feeders are scheduled to go to butcher. Shortly thereafter the sows will farrow, and we will be raising an additional 12-20 piglets.
We run our pigs on a pasture-based system, providing about 1 acre of pasture per 10 head in the spring through fall. 2- or 3-strand electric fencing divides the pasture into smaller paddocks to separate groups by age and feed type. When snow accumulation requires us to turn off the electric fence, we will use hog panels to confine the pigs to smaller sacrifice pastures adjacent to the barn. Though some considerations for winter pork production are similar for both pastured- and barn-based systems, my focus is on management strategies specific to pastured pigs.
As the weather cools, our concern shifts from supplying adequate pasturage and shade to providing adequate shelter. Pigs have a relatively small thermoneutral zone1. This is the temperature where the pig can devote all their energy into growing (feeders) or gestating/ maintaining body condition (breeders). Outside of this narrow range, pigs may have a lower feed conversion rate or require additional feed to maintain appropriate body condition. With 60-70% of the cost of raising pigs attributed to feed2, it is important to create conditions that maintain a tolerable temperature, even on subzero days.
A dry and draft-free shelter is our primary method for creating comfortable winter conditions for our herd. Our system uses a 3-sided pole shed divided into two pens with a hut in each pen. We use a deep bedding system in the huts, adding straw as needed to ensure even a burrowing pig can’t reach the cold floor. The hut roofs are metal, so we prevent condensation from forming and dripping onto the bedding by stacking straw bales on the roof. A narrow gap between the walls and roof allows additional condensation to escape and improves ventilation inside the huts. Nestled into these well-insulated huts, the pigs should be able to generate enough heat to stay comfortable even in below-freezing temperatures.
If a barn isn’t available for winter housing, I have seen successful models using high tunnels with plywood or pallets along the bottom edge to create a barrier that keeps the plastic safe from damage. The doors on these tunnels could be opened just enough to let pigs out to pasture or much wider to vent heat on sunny days. I’ve also seen farms that have very well-insulated huts out on pasture, which might require additional labor to keep them dry during winter storms.
One question that may come up for the swine farmer is if or when to supply supplemental heat, and I’m sure the answer depends on the particular shelter system in use. We provide some supplemental heat, as our goal is to prioritize animal well-being and our own peace of mind. Though maintaining profitability is an essential factor in raising meat for sale, at our small scale we can afford to invest an additional few dollars per animal per year to presumably increase their comfort. We also hope that providing supplemental heat will improve the feed conversion rate of winter-raised feeder pigs and ultimately prove to be a cost-effective decision.
Our general guidelines for providing supplemental heat are: one heat lamp per group of 40-75 lb feeder pigs when the temperature is below 45 degrees Fahrenheit. At 75-100 lbs, we will turn on the lamp when temperatures are below 20 degrees F. For larger pigs, we consider turning on the light only if the pigs are displaying signs of extreme cold, such as excessive piling or refusing to come out of their huts. These guidelines are more applicable to nighttime temperatures, as our hardy heritage breed feeder pigs are often out on pasture as soon as the sun rises, even when daytime temperatures are below the threshold. The mature breeders aren’t quite as active but will leave the warmth of the hut to explore the pasture in the late morning or afternoon. We will provide supplemental heat to winter-born piglets to maintain their thermoneutral zone during the first critical weeks of life.
Winter feeding differs from summer only for the breeders, as the feeders have access to unlimited feed year-round. We follow the advice of one swine nutritional guide,3 which suggests an additional .5 lbs increase in daily feed per sow for every 10 degree F drop below 68 degrees F, unless pigs are over-conditioned. We don’t have a grain bin, so we stock up on gestation and lactation feed in 50# bags and feeder feed in 1000# super sacks. All the feed is on pallets which we can move around and store in the pole barn behind the livestock pens. We try to stock enough food by early December to last until March or April so we don’t have to worry about coordinating feed deliveries during the snowiest months of the year. Rodent traps are preemptively placed around the feed and monitored so that we can keep track of pest presence. A good barn cat would probably do the job as well, if not better.
Clean water access is essential for healthy and fast-growing pigs and can be one of the greatest challenges for winter livestock producers. We use a 70-gallon sheep stock tank with a submersible de-icer. The tank fits under the fence to provide water to both pens. We fill the tank 2-3 times a week with a hose that is fully drained after use to prevent ice from forming a plug inside. In warmer months, it might be feasible to drain a near-empty tank and clean it before re-filling each time, but that’s not possible in freezing weather. To keep water as clean and palatable as possible, I use a homemade siphon to remove the sediment that accumulates in the bottom of the tank before filling the tank with clean water. We avoid these issues in the warmer months by using nipple waterers attached to 50-gallon barrels, which is an efficient way to offer unlimited clean water to pigs. If electricity is not available, manually hauling water 1-3 times a day may be necessary to provide adequate hydration in subzero temperatures.
Manure management is the final consideration with raising pigs in the winter. Pigs are clean animals, despite unfounded stereotypes, and have a designated area for their bathroom needs. However, if this area fills up, they will move to another, and another, which can be a major concern for producers with relatively small pens. Manure and urine left to collect near shelters can create odor, dampen bedding, and provide an environment that promotes diseases. I try to muck out the barn and areas around the pig huts at least once a week. I can usually accomplish this in less time than it takes to re-fill the stock tank. I gather the manure in an informal pile outside the barn that I will transport to a designated composting area when we move the pigs out onto pasture next spring. We are in the process of writing a manure management plan for our farm, which will reduce potential risks from parasites and other pathogens.
Winter can prove to be a difficult time even for experienced swine farmers, with weather creating a variety of challenges unique to pasture-based producers. Managing for cold temperatures benefits farrow-to-finish farms as well as winter feeder pig operations that take advantage of the “off-season” to re-supply their meat inventory before the busy CSA or farmers’ market season begins. With the right infrastructure and a good system in place, many of the cold weather challenges can be minimized. It is possible to raise a healthy herd of pastured pigs, even through an upper Midwest winter.
Sources:
1. https://extension.psu.edu/cold-temperature-management-for-pigs
2. https://www.sare.org/publications/profitable-pork/hog-production-systems/raising-pigs-on-pasture/
3. https://www.asi.k-state.edu/extension/swine/swinenutritionguide/
Additional Resources:
https://extension.umn.edu/swine/small-scale-swine-production
https://extension.oregonstate.edu/collection/swine-resources-small-farms