July 4, 2011

US university recommends ways to combat heat stress in pigs

Pork producers can minimise heat stress for their pigs by taking into account how pigs naturally remove body heat, as pigs do not have functional sweat glands to assist them in efficiently reducing body heat, according to the University of Minnesota Extension.

Instead, pigs remove body heat during periods of heat stress through a combination of accelerated respiration, decreased feed intake, increased water consumption, and adjustments in physical activity and movement.

Cooling systems should be prepared and maintained to ensure proper function, and use of sprinklers along with fans can reduce the temperature in barns as long as the sprinklers are set correctly. Sprinklers that produce a very fine mist should be avoided as they will increase humidity levels in the barn, and cooling cells will be much more effective at lower humidity levels. Ventilation systems should be adjusted to remove excess moisture from buildings.

Since pigs will reduce their feed intake during periods of high temperatures, the feeding program should be adjusted by increasing the nutritional density of the diet for growing pigs and lactating sows. The caloric density may be increased by including increased fat levels in the diet; however, if other nutrient levels are not also increased accordingly, animal performance will still suffer.

Procedures during load-out and transportation of pigs should be modified, as this is the most stressful time in periods of heat. Feed should be removed from pigs for 12 to 18 hours prior to moving them for market, but water should still be supplied. Maximum air movement can be ensured by loading fewer pigs, keeping the vehicles in constant motion and opening all vents and slats, and avoiding the transportation of pigs during the heat of the day.