Heat Wave and Pigs

July 20, 2011 — 

The National Weather Service is forecasting record heat throughout the Midwest and Southeast this summer. Extreme heat is a significant animal welfare and economic concern for swine producers. Given that pigs do not perspire, they rely on evaporative cooling to maintain body temperature. Evaporative cooling is a combination of moisture and air flow. The challenge to keep pigs cool may be exacerbated during transport in elevated temperatures and high humidity.

Heat and humidity can be deadly to pigs. When ambient temperatures approach 100 degrees, pigs may enter a “danger zone” with humidity levels as low as 15% and it can quickly become an emergency when relative humidity levels exceed 35%.

The National Pork Board’s Trucker Quality Assurance Program (TQA) offers some guidelines for transportation during times of extreme weather conditions. The TQA program recommends utilizing the following procedures to keep animals cool and eliminate unnecessary transport losses during extreme weather conditions.

1. Adjust your load conditions (such as stocking density) during temperature extremes.
2. Schedule transportation early in the morning or at night.
3. When the temperature is over 60°F (15°C), use wet shavings to keep hogs cool.
4. If the temperature is over 80°F (27°C), sprinkle hogs with water prior to loading at buying stations or on the farm (use a coarse heavy spray but not mist).
5. Always be prepared to react/adjust to rapid temperature fluctuations such as the first warm day(s) of spring.
6. Never bed hogs with straw during hot weather.
7. Remove slats from farm trucks.
8. Open nose vents.
9. Unplug ventilation holes.
10. Load and unload promptly to avoid heat buildup.

In addition, truckers should be prepared to adjust their routes should there arise significant delays from highway construction or accidents. It is important to keep the trucks moving to promote evaporative cooling of the animals. If there are delays unloading the animals, utilize “cooling stations” (such as fans or misters) provided at some off-loading facilities or keep the trucks moving to encourage continued air flow. Do not park in areas where the air flow may be obstructed by buildings or other trucks. On prolonged trips, it may be necessary to provide the animals with water or to spray them down to keep them cool.