In the Spotlight

News & Features
Heat wave hurting farms
By Laurel Druley, Minnesota Public Radio
August 8, 2001
Click for audio RealAudio

Cows have been hit with hot, muggy conditions as well as an unusual number of insects this year. Milk production is down as a result.
(MPR Photo/Laurel Druley)
About 125 sows died at a large confinement hog operation in North Dakota this week due to hot and humid conditions. Minnesota dairy farmers have seen a drop in milk production as a result of the weather.

DAIRY FARMER DAN FRENCH says his cows are doubly uncomfortable with the muggy weather and a wet spring that lead to an unusual number of insects.

The cows huddle in one corner of the pasture using each other's tails to keep the flies away. French will herd his cattle into the ventilated barn before the sun is at its hottest. He watches his 135 head of cattle carefully for signs of heat exhaustion.

"I saw one a while ago. When they get really hot their tongues will be hanging out and they'll just be panting. There was one that was doing that. That's always an indication. Some of them, they're just like people and they'll complain early," French says.

One of the Midwest farmers most popular cows, Holsteins, are more affected by heat because of their dark skin pigmentation. French moves the cows into the shaded pasture during the day and open pasture at night. When livestock have to deal with hot weather over a long period of time, more of their energy goes into keeping cool than making milk. Although nationwide milk production is down, Dan French is bucking that trend. His production is up. But he says that's not the norm. He owes his success to doubling the amount of dry feed the animals get. Most farmers haven't been so lucky.

Dairy Farmer Dan French says he takes his 135 head of cattle off the pasture when the sun is at its hottest and into a ventilated bard with plenty of water.
(MPR Photo/Laurel Druley)
Sandra Godden, a professor at the University of Minnesota's veterinary hospital, says cows are like humans. They're fixated on staying cool. "They spend more time trying to dissipate heat and less time eating less time relaxing, so typically what we see in the summer with this type of heat stress is hot, panting cows that are uncomfortable. They're eating less, their milk production drops and we do see increase in incidence of infectious disease and metabolic disease," according to Godden.

Godden recommends keeping animals in ventilated barns on high ground where air moves through. Industrial-sized fans and sprinklers to keep animals cool. And providing plenty of clean water is also important.

Farmer Dan French installed large fans in his barn to make sure milking time is pleasant for humans, and animals. "When we go to milk," he says, "we turn on the fans and shut all the doors except for the one by the parlor and it's like a wind tunnel. They understand that and they're really willing to go into the barn and it's a lot cooler for them."

Heat stress begins at 72 degrees for a cow. More severe heat stress can set in at 80 degrees. Calves or older cows are even more at risk. Large animal specialists at the U of M say they've seen a handful of deaths due to heat stroke this summer.