Sows and gilts housed in open-sided facilities through winter may need additional feed nutrients to accommodate for cold temperatures. Additional bedding and management of drafts can also help minimize chilling of animals.
Cold temperatures can be problematic to long-term sow performance if not accounted for. Fortunately, changes can be made before temperatures drop too low and sows are impacted. Two strategies for mitigating cold stress are facility air movement and adjustments in sow rations.
Air temperature and air flow can impact sows performance through winter. Though sow body heat can help keep air temperatures adequate, curtain sides and mechanical ventilation must be evaluated to prevent excessive air movement that could cause a ‘wind chill’ effect inside climate-controlled barns.
Industry research shows that cold temperatures can cause sows to lose body condition which, in turn, can impact: fertility, milk production and piglet survival and growth performance – resulting in potential declines in sow longevity and parity structure in the herd.
Vern Pearson, Ph.D., swine nutritionist for Purina Animal Nutrition, recommends evaluating air temperature, air flow and sow rations in the facility to reduce the risk for cold stress in sows.
Air flow and temperature
Recommended seasonal facility changes vary based on the type of facility.
Pearson says that air temperature is not usually a severe challenge in curtain-sided or environmentally controlled gestation and farrowing barns, but that air flow can cause concern.
“In these facilities, adult sows typically provide enough heat to warm the barn,” he says. “We need to evaluate mechanical ventilation, however. Be sure that mechanical ventilation, which is needed for airflow in the summer, does not create excessive air movement that could cause a ‘wind chill’ effect inside climate-controlled barns.”
Both air temperature and air flow can be problematic in open-fronted and open-sided barns used to house sows. In these settings, additional bedding and management of drafts can help minimize chilling of animals.
Cold-weather sow rations
Pearson says that the most common impact of cold temperature stress is that sows do not consume enough feed in the winter to maintain their condition. Decreases in body condition score (BCS) below the ideal 3 on a 5-point scale can set sows back in long-term performance.
“We need to keep sows at a BCS of 3, which may require more feed during cold temperatures,” he says. “As temperatures decrease, sows require more feed to regulate their cold body temperatures. Without added nutrients, the sow will allocate resources away from other body functions.”
In addition to body condition maintenance and litter support, sows require energy to generate internal heat during cold periods. Researchers at Mississippi State University Extension estimate that up to 25 percent more feed is required by sows during extremely cold conditions.
Tips to help maintain consumption levels and meet this higher nutrient level include:
- Provide fresh feed several times throughout the day to account for the sows’ instinct to consume more during cold spells.
- Increase the content of high-fiber ingredients including: oats, barley, beet pulp, wheat bran, DDGS, alfalfa meal and soybean hulls. The bulk of these materials can help increase the amount of heat produced by the sow for digestion, slow the ration passage rate, dilute the energy concentration of the ration and often reduce overall ration costs.
- Add fat to the ration to increase energy levels, based on the age, stage of gestation and BCS of the sows.
- Feed according to stage. Generally, first-litter gilts have greater nutritional needs as they grow to their mature size. Late-gestation and lactating sows of all ages need more energy to support birth and weaning weights and milk production. And thin sows need additional energy to withstand cold conditions without sacrificing additional body condition.
- Ensure that sows have access to fresh, unfrozen water at all times. Water helps regulate body temperature and can impact feed intake; determine a back-up system for heated water to account for power outages or frozen water lines.
“It’s a combination of management factors that helps sows thrive through winter,” Pearson says. “The correct combination of ration adjustments as well as air temperature and air flow management can help producers set sows up to perform long-term through the cold season.”
For more information on seasonal sow nutrition and management, visit www.swine.purinamills.com or contact Vern Pearson at 651-375-5582; or email: [email protected].
 Rozeboom, K.J., M. Todd See and W. Flowers. “Management practices to reduce the impact of seasonal infertility on sow herd productivity.” North Carolina Cooperative Extension Service. Publication No. ANS00-8138. www.ncsu.edu/project/swine_extension/publications/factsheets/813s.htm. 5 May 2013.
 “How should swine operations prepare for winter?” Mississippi State University Extension. msucares.com/livestock/swine/winter.html. 25 September 2013.