Pigs may respond to high temperatures (those above 73.5º F to 77º F) by reducing feed intake and increasing water consumption in an attempt to minimize heat generation. This, of course, can stall growth rate and reduce sows’ milk production during lactation.

It’s worth reviewing clinical signs of heat stress with workers and talk about how to take appropriate preventative actions. Luiz Souza, animal scientist at the University of Minnesota, provides the following strategies to minimize heat-related production losses.

  • Feed intake. One practice to help minimize heat stress’ effects is to add supplemental fat to the diet and increase concentrations of other nutrients. Another change that can help is reducing the crude protein content by using synthetic amino acids. If hogs are fed on a schedule, you might want to adjust it so that feed is provided during the coolest periods of the day.
  • Respiration. Respiratory rate is a reliable heat-stress indicator. When pigs are in a resting state, rates above 50 respiration movements per minute reflect heat stress.                            
  • Water consumption. Increased water consumption can lead to increased excretion of important minerals that are involved in metabolism and electrolyte balance. So watch nutrient levels. Also, ensure that fresh, quality water is available to pigs at all times.
  • Activity. It is natural for animals in hot environments to reduce their activity as they try to minimize body heat. In some cases, less standing can cause or aggravate urinary infections and may lead to fertility problems in sows.
  • Equipment. Check cooling systems to make sure they are working properly, including thermostats, fans, air inlets, drip coolers and sprinklers. Make sure all air inlets and fans are clean and working properly. Check sprinklers to make sure they are functioning properly in all locations.
  • Transportation. The bottom, center and back middle decks of trailers can be dangerous spots on hot days. Watch these areas of the truck carefully. Have cooling mechanisms and protocols in place. Transport animals during the coolest times of the day, and allow extra animal space inside the trailer.Be aware of weather forecasts and be prepared with contingency plans during weather extremes.