Understanding Heat Stress in Pigs
Causes and Solutions

Pig farming is a challenging business that requires a lot of attention to detail. One of the critical issues that pig farmers face in their production is heat stress, which leads to decreased productivity, sub-optimal animal welfare, and increased mortality rates. In this article, we will explore the causes of heat stress in pigs and possible solutions to reduce the problem.


Climate changes: warmer summers and more extreme weather

One of the primary causes of heat stress in pigs is climate change. Warmer summers and more extreme weather conditions have made it difficult for pigs to regulate their body temperature, leading to heat stress. Pigs are known to have a narrow thermoneutral zone, which means that any deviation from the optimal temperature range can affect their performance.


Change in genetics: older pig houses are dimensioned for smaller sows and fewer piglets

Another factor contributing to heat stress in pigs is the change in genetics. Over the past 30 years, the average sow has grown by 50 kg, and the number of born piglets has increased from 10 to 18. However, older pig houses are dimensioned for smaller sows and fewer piglets, so the animals are overcrowded, leading to heat stress.


What are the symptoms?

Heat stress can have significant impacts on the health and well-being of pigs. One of the main symptoms of heat stress is rapid breathing, which can be accompanied by reduced appetite, weight loss, and decreased productivity. In addition, animals suffering from heat stress may experience a decrease in their overall activity level, reduced fertility rates, and a lower farrowing rate. Other symptoms of heat stress can include the development of shoulder lesions, which can be painful and weakening. In severe cases, heat stress can result in death due to heat stroke.


Reducing heat stress

It is crucial to consider the pig’s comfort level when addressing heat stress. Factors such as temperature, ventilation capacity, cooling, and air velocity (chill effect) must be optimized to provide the animals with optimal climate conditions. Some of the ways to keep the experienced temperature in the pig house at a comfortable level include:

  • Increasing ventilation capacity: This can involve more fan capacity, which will both lower the indoor temperature and increase the air velocity.
  • High-pressure cooling: This method uses demisting and evaporation of water to reduce the temperature in the room and thereby lower the temperature of the pigs' environment.
  • Pad cooling: Cooling pads can evaporate water and lower the indoor temperature, making it more comfortable in the pig’s living area.
  • Air velocity: Systems that increase the air velocity will lower the experienced temperature that the pigs feel in their occupation zone. Wall and ceiling inlets can create some air velocity, but the highest air velocity is achieved using a system, such as an LPV+ or Combi-Tunnel system.

Besides providing an optimal climate by choosing the right system, pigs must have access to clean and fresh water to regulate their body temperature and stay hydrated.

The SKOV systems that can create the highest cooling capacity are LPV+ or Combi-Tunnel systems. A pure Tunnel system can be used in tropical climates instead of a Combi-tunnel system.

Read the case of Scandinavian Farms Pig Industries in China, whose updated system led to reduced heat stress and increased production.