Submitted to: Applied Engineering in Agriculture
Publication Type: Research notes
Publication Acceptance Date: 1/24/2002
Publication Date: 5/20/2002
Citation: EIGENBERG, R.A., NIENABER, J.A., HAHN, G.L., KACHMAN, S.D. SWINE RESPONSE TO MISTING SYNCHRONIZED WITH MEAL EVENTS. APPLIED ENGINEERING IN AGRICULTURE 18(3):347-350. Interpretive Summary: Pigs eat less feed during hot summer months and do not grow as quickly. Air conditioning is too expensive to be considered but spraying pigs with water helps to reduce stress. However, spraying increases the humidity and adds to the waste water. Our information shows that the body temperature raises as the pig eats and may cause the pig to stop eating. Cooling the pig with spray, just before it eats, has been shown to increase the size of the meal. This strategy minimizes the water usage and humidity and may improve the growth rate of pigs over hot summers.
Technical Abstract: Prior work has shown that the tympanic temperature of swine increases during an eating bout. An experiment was conducted in a hot environment using timing of misting as a way of reducing the body temperature during meal events. Three treatments were applied to pigs in a constant temperature 30C environment: no misting, misting just prior to meals, and misting between meals. Two response variables were examined: feed intake and meal duration. Three environmental chambers were used in a Latin-Square layout with each chamber hosting each treatment. Analysis showed feed intake was significantly (P<0.05) increased by misting just prior to the meal when compared with no misting or misting between meals. Similarly, meal duration was significantly greater (P<0.05) for misting just prior to the meal than for the other two treatments. The meal effect appears to result from cooling the pig, thereby reducing the tympanic temperature spike that normally occurs during an activity event such as a meal. The moderation of the body temperature apparently allows the pig to eat for a greater period before thermoregulatory controls restrict the meal duration and hence the meal amount. While not conclusive from these short-term observations, increased feed intake should benefit growth performance.