Heat, Humidity Affects Cow Milk Production

Posted at: 07/16/2013 6:13 PM
Updated at: 07/17/2013 7:25 AM
By: Tim Sherno

As heat and humidity climb, the combination makes people uncomfortable, but the one-two punch is a larger issue for milk-producing cows.

Dr. Marcia Endres, Ph.D., is with the University of Minnesota Extension and describes herself as a "Cow Comfort Specialist." She says higher temperatures can reduce a cow's milk production, "Anywhere from 10-15 percent, or about 5 to 15 pounds, or up to two gallons a day per cow."

One concern is the duration of hot weather. Dr. Endres says it takes a few days for a milk producing cow to display symptoms of heat stress, but the effects can last much longer. "If the heat lasts for a very long time, her production probably will never recover to the level it was before the heat stress."

The University of Minnesota is currently looking for ways to warn dairy farmers that a cow is beginning to experience heat stress. One concept being researched makes use of a radio thermometer sealed in a plastic capsule that is placed in one of a cow's stomachs.

Dr. Endres says the device reports on the cow's temperature every 15 minutes and could potentially send an email or text to a dairy farmer to alert them to a potential problem before it has a chance to escalate.

According to Dr. Endres, the best temperature for a cow is 50 degrees, and a cow starts to feel the effects of heat when temperatures climb to 70 degrees. Dr. Endres says that while there are ways to cool cow's temperature, the hope is to reduce the impact heat can have on a cow's production.