Keep Cattle Cool

Experts: Watch for Heat Stress in Beef Cattle

Russ Quinn
By  Russ Quinn , DTN Staff Reporter
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Cattle producers can determine the risk of heat stress handling by referring to the Beef Cattle Temperature Humidity Chart. (Chart courtesy of Rob Eirich, UNL Extension)

OMAHA (DTN) -- Cattle producers should be extra cautious when handling cattle during periods of hot, humid weather during the remainder of the summer, livestock experts say. Regardless of whether they have a cow/calf herd or a feedlot, there are certain precautions cattlemen should remember as the temperature increases.


For cow/calf producers, heat stress can have a negative effect on cattle performance and conception rates. There are some basic steps producers can take to avoid problems with heat stress.

Taylor Grussing, South Dakota State University cow/calf specialist at the Mitchell Regional Extension Center in Mitchell, South Dakota, said increasing water access for cows and calves is recommended during hot days.

Producers can move cattle to pastures with more water sources or deliver water to the cattle. South Dakota's dry conditions this summer has been drying up water sources, already leading cow/calf producers to already do this some parts of the state.

"You want to make sure cattle have 3 linear inches per head access to water; calves would obviously need less," Grussing told DTN. "So, for 200 head, you would want to make sure there is about 600 linear inches of water for the herd."

Cow/calf producers can also avoid heat stress in cattle by making sure cattle have access to shade. That could involve moving cattle to areas with trees or building structures -- either temporary or permanent -- to provide shade.

Grussing said some cattlemen don't like to graze cattle in pastures with too many trees, since they believe cattle will just stand in the shade and not graze enough compared to unshaded grasslands. The cattle will still graze in grasslands with trees, but will select cooler times of the day to graze, she said.

Cattlemen can also spray down the cattle if they have access to these areas or if they are in dry-lot production. A sprinkler could be used as well. However, producers should use a larger droplet size or they risk just adding more moisture to an already moist environment, she explained.


Providing shade and sprinklers are also important to help limit heat stress in feedlot cattle. Rob Eirich, University of Nebraska-Lincoln (UNL) Extension educator and director of Beef Quality Assurance located at the Panhandle Research and Extension Center in Scottsbluff, Nebraska, said airflow in feedlot pens is very important to help animals cool down.

UNL developed a chart to help producers determine the risk facing cattle based on the temperature and the percent of relative humidity, Eirich said. The chart is based on research done by UNL and the USDA Meat Animal Research Center in Clay Center, Nebraska. The chart can be found at…

Eirich recommended that on hot days feedlots should process cattle early in the morning hours before 10 a.m.

Some people believe it's also good to handle cattle in the evening, but there is still a risk due to the animal's body temperature being elevated from high temperatures, Eirich said. The animal's body temperature will peak about two hours after outside temperatures peak and will take four to six hours for the body temperatures to return to normal. Early morning is still the best time to work feedlot cattle, he advised.

Eirich recommended that during the hottest season cattle be worked in smaller groups so they don't stand in holding areas much longer than 30 minutes. Cattle producers should also consider having shade and good air movement in facilities.

"Work cattle slowly and use low-stress handling techniques," he said. "Processing cattle in any temperature elevates the animal's core temperature."

Eirich also suggested feedlot operators should consider reading UNL's NebGuide titled "Feedlot Heat Stress Management Guide" which can be found at….


Grussing said she would also recommend cow/calf producers think about fly control during hot days. Proper fly control can keep animals more comfortable even during hot conditions.

"I would keep an eye on how well your fly control measures are actually working on these warm days," she said. "If you need to take additional methods to control flies, then do so."

Grussing said she would also recommend giving cattle some sort of feed supplementation during hot summer days. With the current dry conditions in South Dakota, many cattle are being fed hay since the grass hasn't grown much.

Under such conditions, cow/calf producers should also consider weaning their spring calves earlier than normal to conserve grass, she said. If you wean Oct. 1, consider weaning on Sept. 1, Grussing said. Cows without calves would take less grass, so the grazing season could be increased.

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Russ Quinn