Summer temperatures are quickly approaching which poses the potential for heat stress in livestock; especially hogs as they do not have functioning sweat glands.  While other animals use their sweat glands to help cool down, hogs must resort to other strategies to reduce the amount of heat generated in their bodies.  Extended periods of temperatures in the mid 90’s coupled with North Carolina’s high humidity is very stressful physically on hogs so it is important that farmers take the necessary steps to help minimize their heat stress as much as possible.

Prolonged heat stress can lead to less than adequate feed conversion, decreased growth rate, and increased mortality.  During daily animal check, farmers should look for symptoms of heat stress.  Increased breathing rates or panting is the first and most noticeable symptom. Producers will also notice decreased hog activity and feed consumption as well as increased amounts of water consumption.  All of these are part of a hog’s natural efforts to cool his body; however, always seek the advice of your animal healthcare professional if you feel the hogs in your care are in need of additional attention.

Here are a few steps to reduce the heat stress on hogs:

  • Floor Space – Reduction in stocking density as much as possible will play a major role in heat stress reduction. Increasing the floor space for hogs gives them more space to lie down and they will have less contact with other hogs, thus giving them the opportunity to better dissipate heat.
  • Ventilation – Adequate ventilation systems in great working order are vital to heat stress reduction. Systems should be checked often for mechanical failure and kept free of dust or any other obstructions.  Air movement over the hogs increases their rate of heat loss and will help decrease the humidity in the barns.
  • Sprinkler Systems – Sprinklers are often used in barns as an effective supplemental source of cooling; however, they must be working properly according to manufacturer’s specifications and those of your animal healthcare professional. For example, sprinklers should not spray continuously or leak over the hogs as this will increase humidity.   They are most effectively used by allowing time for the moisture to evaporate between periods of spraying.
  • Water Availability – Adequate availability of water is the most important factor in heat stress reduction in hogs. During periods of heat stress, hogs can increase their water intake by as much as six times their normal level.  Waterers should be adjusted and functioning properly to provide the hogs with quality water whenever wanted.

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Adapted from an article by Dr. Luiz Souza, Department of Animal Science, University of Minnesota