Click on “Download PDF” for the PDF version or on the title for the HTML version.

If you are not an ASABE member or if your employer has not arranged for access to the full-text, Click here for options.

In summer, cooling systems are applied in some swine buildings in China to alleviate heat stress on pigs. Cooling lying-bed systems incorporating circulated water have been developed quickly in China because they have advantages such as: no change of environmental humidity compared to spraying cooling systems; and no high air speeds to blow over the pigs bringing unhealthy conditions to pigs compared to the conventional ventilation system. An ideal cooling lying-bed system should be circulated with low temperature water (15C-18C) for pigs experiencing above30C ambient temperature. An excellent cooling lying-bed should provide high heat transfer rates; the surface temperature should be comfortable for the pig lying on the pad; the cooling water flow resistance should be low; and the price of each lying-bed should be affordable.

This paper discusses temperature difference between the surface and the water of four types of cooling lying-beds at two running way, and the temperature ascend rate at simulative way. Four types lying-bed include: #1 made of concrete and labyrinth water trough, #2 made of concrete and iron water pipe buried in concrete, #3 made of iron plate-pipe covered 5mm thickness concrete layer, #4 made of concrete water trough and concrete rib covered sealing iron gland. Experiments showed that the temperature difference between the surface and water decreased in order of #2, #4, #1 and #3. #3 showed the best cooling effect .The temperature ascend rate increased in order of #1, #2, #3 and #4. #1 had the most heat capacity, which was suitable for pigs lying on longest. #4 had the lowest thermal inertia. #3 had the highest cost for the plate-pipe made of iron and #1, #2 and #4 had matched cost. However, #1 should be proposed