While cattle can usually tolerate high temperatures, producers need to keep an eye out for heat stress as summer moves into August.
Becky Funk, a veterinarian with the University of Nebraska’s Great Plains Veterinary Educational Center in Clay Center, says the temperature alone is not the issue — it’s the cumulative heat load that is often increased by high humidity and little wind.
“Day 1 generally isn’t an issue, but it’s Day 2 and Day 3 that can become a problem, especially if it does not cool down at night,” she says.
Funk say signs of heat stress include open mouth breathing and congregating around the water tank or in small pieces of shade. She says plenty of water needs to be available for both cattle in the feedlot and cow-calf pairs out on pasture.
Providing shade in the feedlot would be beneficial, Funk says, but adds it can be expensive.
“For something that you might only need a few days in the year, it can be expensive,” she says. “It has to be designed so it doesn’t impact air flow. You want more than just a tarp covering some area.”
While heat stress in the feedlot could result in extreme health issues and even death loss, producers should be concerned about cattle out on pasture. Funk says severe heat events can cause milk loss in cows, for example.
“For those who calve in late summer, newborn calves can’t regulate their body temperatures, so you could have some trouble there,” she says. “You may not see catastrophic losses out on pasture like you might in the feedyard, but heat stress is still an issue.”
Spraying cattle with water in the feedlot can help cool them down, but Funk says to make sure the spray is comprised of large drops. She says water can act as insulating agent for heat.
Fresh bedding in the feedlot can also help. Funk says bedding will decrease surface temperatures, but adds using it will require some extra maintenance.
Heat stress is generally not an issue with hog production, says Chris Rademacher, Iowa State University Extension swine veterinarian. He says as long as hogs have access to cool water and proper ventilation, there should be few heat-related issues.
Feed intake drops in the summer due to heat, and Rademacher says once the temperature reaches 82 or 83 degrees, pigs will start to feel some stress.
“They are going to want to wait until evening to eat, and that’s a tough task,” he says.
Rademacher says producers need to check flow rates in the waterers, suggesting something in the two cups per minute range.
“Make sure they aren’t plugged and sufficient water is flowing,” he says.
In curtained building, misting can help keep hogs cool. Rademacher says moving air through the building is going to help dissipate heat.
“Make sure the curtains are going up and down like they are supposed to, and double check the fans to make sure they are working correctly,” he says, adding dust buildup will affect the efficiency of the fans.
Producers also need to make sure all backups are functioning in the event of an emergency. Rademacher suggests all emergency systems be checked at least monthly.