Researchers at UC Davis have been testing cooling technologies to address the heat-stress experienced by California dairy cows. Current cooling methods include the use of fans and sprinkler systems that require a substantial amount of electricity and water. The Western Cooling Efficiency Center and the Department of Animal Science at UC Davis are looking at approaches designed to reduce water use by up to 86 percent and electricity usage by up to 38 percent compared to current standards.
There are two methodologies that are being tested. One is comprised of targeted convection cooling. Air is cooled by a high-efficiency evaporative cooler that is directed onto cows while they eat or when they are at rest. Paul Fortunato, Outreach Manager for the Western Cooling Efficiency Center at UC Davis, noted the ingenuity of how the cool air is funneled. “I think what’s interesting about this solution is the use of a fabric duct system, which I think significantly reduces the cost.”
The other method involves conduction cooling, which includes cooling the bedding area where cows lie down using heat exchange mats. “Think of a bunch of small plastic pipes that have chilled water running through them and that mat is just buried underneath the ground where the cows actually lay down, so then they get cooled by that conduction,” said Fortunato.
The water that flows through the mats is cooled by a Sub-Wet Bulb Evaporative Chiller to help lower energy consumption. “It’s using evaporative cooling, but instead of cooling to cool air, this time it’s to cool water,” Fortunato stated.
According to the International Dairy Foods Association, California’s dairy industry has an overall economic impact of more than $29.5 billion. The state is also responsible for 19 percent of the nation’s milk production. Disruptions in production can have a significant impact on the entire industry. The process of milk production, along with rumination, already creates a lot of heat in dairy cows. Combining that with high temperatures makes it difficult to keep cows cool enough to not adversely affect production levels. Fortunato noted that “heat stress, according to our documentation, just in California alone basically accounts for over $800 million of annual losses.”
The research for the new cooling technologies is part of a four-year, $1 million grant from the California Energy Commission designed to increase water and energy efficiency in the dairy industry. The information collected will help establish which technology should be used in the development of a commercial dairy in a future component of the project.