In collaboration with a private company, scientists from the Faculty of Agricultural Sciences have developed a floor element for pig houses that can help pigs regulate their body temperature. A new report describes a strategy for controlling the supply water temperature to the floor elements.
Modular floor elements that are being developed can cool or heat pigs lying on them according to the pigs’ temperature requirements. Photo: Janne Hansen
When we humans feel really hot we can lie on a sun chair under a shady tree. When we feel cold, we can go inside and tuck under a cosy duvet. Pigs in modern housing do not have these choices. However, their possibilities for regulating their environment are moving towards improvement.
Scientists from the Faculty of Agricultural Sciences, Aarhus University, have collaborated with the animal housing heating company Spiraflex A/S in developing floor elements for pig houses that can either cool the pigs or keep them warm, depending on the requirements of the pigs. This will not only improve pig welfare. It will also benefit production because the pigs will no longer need to waste energy on regulating their body temperature but can instead spend their energy on growing.
The floor elements are connected to a heating and cooling system and are controlled by the pigs’ requirements for access to either a cool or a warm place to lie. The floor elements are supplied as modules and are meant for use in weaner and finisher houses.
Part of the work the scientists carried out consisted in describing a strategy for controlling the flow temperature to the floor elements as a function of house temperature and pig weight with a focus on cooling.
- Pigs cannot sweat. As the temperature in the pig house increases their possibilities for getting rid of excess heat becomes a liability and they may start wallowing in wet manure so that evaporation from their skin cools them. This will lead to poorer hygiene and they may eat less and thus grow less, says consultant Jan S. Strøm from the Department of Biosystems Engineering at the Faculty of Agricultural Sciences.
The basic idea is to remove the heat that the animals cannot get rid of to the air when the house is very warm by circulating cooled water through the floor elements that the pigs lie on. The floor elements were first tested on an artificial pig in the laboratory. With the aid of this test pig the scientists could determine how effective the floor elements were at transferring heat from the pig to the floor.
Afterwards, the system was tested on real pigs in a research pen. Here the floor elements were shown to be functional and durable. However, the results from the trial were difficult to interpret because in several cases the pigs chose the slatted floor as resting area instead of the cooled floor, thus indicated that the thermal comfort criteria for the pigs were not met.
- Pigs are sensitive with regard to the temperature in their lying area and will move if the temperature does not suit them We still do not have a basic understanding of how pig perceive comfort, including how to improve it under hot conditions. Until this knowledge is achieved the new floor elements cannot be product developed and marketed. However, they can be used for research purposes to improve the physiological and behavioural knowledge about pig preference for and rejection of cooled or heated floor surfaces.
The project "Modular floor elements for cooling and heating in weaner and finisher houses" was carried out in collaboration between the Faculty of Agricultural Sciences and the animal housing heating company Spiraflex A/S (now SKOV A/S), that coordinated the work. The project was financed by the Ministry of Food, Agriculture and Fisheries.