Most dairy farms in the U.S. use some sort of cooling mechanism in hot summer months to keep cows cool. It has been well documented that keeping cows cool in periods of heat stress can provide economic benefits in the form of improved reproduction and milk production.
The electricity and water used to cool cows doesn’t come without a cost of its own. However, the benefits of keeping cows cool outweigh the additional cost in energy. But, what if you could keep cows cool without the expense of electricity and reduce your water use?
Research projects in Arizona and California have been evaluating a new method of cooling cows called conductive cooling. So far, the results are promising and this new technology could offer dairy farmers an opportunity to cut energy cost.
How does it work?
Conductive cooling works through direct surface contact between a warm source and a cold source, transferring or exchanging heat to cool an animal.
Much like a dog cooling itself by lying on cold tile floors, heat is transferred from the dog to the colder surface of the tile floor. The same thing happens if you cool free-stall beds — heat would be transferred between the cooled free-stall bed and the cow.
To get the free-stall beds cool, a heat exchanger is buried approximately 12 inches below the surface of the free-stall. (Burying it 12 inches below the free-stall bed prevents it from being snagged by grooming rakes.) Well water (60 degrees F to 70 degrees F) pumped from an existing well passes through the heat exchanger system under the freestall bed on its way to another function on the dairy.
With about a 30 degree F to 35 degree F difference between the temperature of the cow and temperature of the well water, heat is transferred between the two, says Jim Bruer, general manager with Agriaire. Agriaire has a patent pending on this new cooling system.
Another way to cool free-stall beds is to use a chiller to re-circulate chilled water through the heat exchanger. Water would stay in this closed loop system and not be used for other purposes on the farm.
Concern has been raised that dampness through condensation might be an issue, says Tim Steele, primary engineer with Agriaire. “We’ve done a number of tests, using extreme temperatures and extreme humidities, and condensation in the bedding has not been an issue.”
Cut energy use
Energy to operate fans and pump water to cool cows is expensive. It is estimated that 10 percent of energy use on-farm is dedicated to air circulation.