Reducing heat stress in swine

It is that time of year again where elevated temperatures are upon us which always triggers the potential for heat stress in our livestock; especially hogs as they do not have functioning sweat glands. While other animals perspire 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 are very stressful physically in swine so it is important that farmers take the necessary steps to help lessen heat stress as much as possible.

Prolonged heat stress can lead to less than adequate feed conversion, decreased growth rate, and increased rates of mortality. During daily animal observations, farmers look closely for symptoms of heat stress in their animals. Increased breathing rates or panting is one of the first and most noticeable symptoms. Producers will also notice decreased hog activity, decreased feed consumption along with increased water consumption. All of these are natural efforts to cool their 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.

Listed below are some steps to reduce the heat stress on hogs:

• 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 well positioned and functioning properly at all times to provide the hogs with quality water continuously.

• 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. It is recommended to keep fans greased and keep a close eye on fan motors and belts to be sure they are in working order. Air movement over the hogs increases their rate of heat loss and helps decrease the humidity in the barns.

• Floor Space – Reduction in stocking density can play a role in heat stress reduction. Increasing the floor space for hogs gives more space to lie down and they will have less contact with other hogs, thus giving them the opportunity to better dissipate heat.

• Sprinkler Systems – Sprinklers and are often used in barns as an effective supplemental source for 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.