Don't let heat undermine performance: Seasonal prep for swine operations
Warm weather effects start earlier than many people think and can impact pig performance if not managed properly.
29 June 2026
3 minute read
By: Key takeaways
- Warm weather effects start earlier than many people think and can impact pig performance if not managed properly.
- Focus on the basics like ensuring proper climate control and intake of feed and water to maintain productivity in summer months.
- Preparation is critical, including routine checks of ventilation, water and cooling systems to help prevent costly losses.
Historically, the rise of outdoor temperatures is a signal to properly prepare barns so animal comfort is maintained and stress is minimized. Warm weather can potentially impact health and performance at all production phases and, in some cases, can prematurely lead to mortality.
Heat stress affects the physiology and metabolism of swine. It leads to decreases in appetite and growth rate, which reduces productivity. It also hampers a pig’s digestive capacity and can cause a reduction in lean tissue. When warm weather arrives, the impact of heat can hurt herd performance as much as any viral or bacterial infection.
With sufficient preparation and a few simple strategies, swine operations can effectively manage heat stress, making it possible for pigs to live more comfortably and reach their full potential, experts say.
“It’s making sure the basics are correct: food, water and air,” said Emily McDowell, DVM, a veterinarian with Pipestone Veterinary Services in Pipestone, Minnesota. “It’s making sure the water flow is good and the ventilation and evaporative cooling sprinklers are set appropriately.”
According to the University of Minnesota Extension, heat stress begins to affect sows, boars and finishing pigs at about 70° F.1 A decrease in performance and reproductive efficiency can occur when temperatures remain above 80° F for more than two to four days.
Beating the heat takes time and preparation. Key areas to consider when preparing for the season include:
- Air and ventilation systems
- Water supply
- Changes to feeding and other schedules
Preparing air and ventilation systems
As temperatures rise and begin to impact pigs, ensuring air and ventilations systems are properly prepared can help maintain performance and animal comfort.
McDowell said curtains, inlets and fans are critical to maintaining air flow. The fans pull out the hot, humid air and replace it with cooler, drier air. She also emphasized it is important to ensure fan blades have been cleaned and the fans are plugged in and working.
“It is critical teams check the emergency curtain drops and all backup equipment and generators are in good working order,” McDowell said. “Evaporative cooling misters are important to wet the animals and air flow over the pigs help to pull heat away in the warm weather. Misters and sprinklers should be set on timers that cycle on 10% of the time when the room temperature rises 15° F to 20° F over the set point.”
Checking water supplies
McDowell recommended monitoring water sources daily. This is particularly important for farms receiving new pigs from other farms.
“Before the pigs arrive, make sure there is enough water and all sources are adequate and functioning properly,” McDowell recommended. “There should be one nipple waterer to 10 pigs in each pen with a minimum flow rate of two cups (16 ounces) per minute for pigs that weigh less than 50 pounds and one quart (32 ounces) per minute for larger pigs.”
She recommended farms adjust the nipple bar height to the height of the pigs’ shoulders. McDowell also mentioned it is helpful to reduce the water pressure when receiving newly weaned pigs so they are not sprayed in the face when trying to drink. Frequent cleaning of cup waterers is an important aspect of ensuring a fresh, clean water supply is readily available during the warm season.
Adjusting feeding schedules
Heat stress can reduce appetite, so adjusting feeding schedules to take place during the cooler part of the day is key to maintaining performance. McDowell suggested scheduling work tasks, such as feeding or checking pens, to occur during the coolest times of the day to avoid disrupting animals during the hottest times.
“Feeding later at night, after temperatures begin to cool down, may help maintain intake,” McDowell said.
As temperatures climb, proactive preparation can make the difference between maintaining performance and facing costly setbacks. By focusing on ventilation, water access and production strategies, caregivers can help minimize the impact of heat stress.
