With temperatures heating up, cattle producers need to take steps to protect their herds from heat stress, a University of Nebraska-Lincoln beef specialist said.
"Cattle do not handle heat stress as well as humans," said Terry Mader, beef specialist at UNL's Haskell Agricultural Laboratory near Concord. "Sunny days with temperatures above the mid-80s can be stressful, particularly if there is no wind and humidity is above 50 percent."
Providing cattle with plenty of water is probably the best way to prevent heat stress, Mader said.
"The cattle don't have to be thirsty, but as cattle drink water and pass it through their body, it removes a lot of heat in the process," he said.
Cattle normally take in about 5 to 6 gallons of water per day, but that amount can triple when temperatures rise.
In an emergency, cattle can be sprayed with water to cool them down.
"Once you start doing that, though, you have to keep doing it," Mader said. "By spraying them and using evaporative cooling, you limit the animals' ability to adapt to the heat. That's why this is an emergency step."
Producers should have an emergency plan for accessing water in case water supplies are low or cut off, Mader added.
In addition, producers should avoid handling cattle when it's hot and never process after 10 a.m. Cattle body temperatures can rise 0.5 to 3.5 degrees during handling.
Producers should feed cattle most of the day's feed several hours after the day's peak temperature, in the late afternoon or evening. Avoid filling cattle up with feed late in the morning when added heat generated by digestion will peak around the hottest time of the day, Mader said.
Cattle yards should be clear of any structures that restrict airflow. Cutting down vegetation around pens and moving cattle away from windbreaks can all help. Building earth mounds in pens also can increase airflow by preventing cattle from bunching together. Spraying water on the mounds will cool the pen surface and help cattle to better manage the heat.
Producers should watch their cattle for signs of heat stress. Cattle will begin walking around the pen in search for cooler spot and start to slobber. They will raise their heads to make it easier to breathe because their respiratory rates will reach above 100 breaths per minute.
Cattle with dark hides, cattle close to being finished, newly-arrived cattle and cattle suffering from illness or recovering from illness will be especially susceptible to heat stress.
For more information about managing heat stress in feedlots, consult UNL Extension NebGuide G1409, Managing Feedlot Heat Stress, available from local UNL Extension offices or on the Web.
- Late Spring 2010