Rising temperatures increase heat stress risk
As temperatures continue to soar across much of Wyoming, range cattle producers should consider the impacts of the weather on their herd, as well as management strategies to reduce heat stress.
“Temperature and humidity are two of the main things that impact the likelihood of heat stress,” says Wyoming State Veterinarian Jim Logan.
Hot temperatures can have a large impact on cattle’s normal grazing habits, as well as their performance.
“Cattle that get stressed from too much heat can dehydrate more quickly, and a lot of times, they’ll go off feed,” says Logan.
He continues, “They’ll shade up more than normal. As a result, they won’t graze as much, so their rate of gain or maintenance will be impacted.”
Cows with calves on their side may produce significantly less milk if they become dehydrated, impacting the calf’s growth and performance, as well.
Increased environmental temperatures can dramatically increase the amount of water required for animals, and producers may need to consider additional water source options for their herd.
“If the temperature gets hot and it’s above 80 degrees, a 10 to 15 degree increase in the temperature can increase an individual cow’s water requirements 2.5 times,” explains Logan.
The habitat cattle live in also has a large impact on their susceptibility to heat stress, says Logan.
“If they’re on lush, green grass where there’s a good water supply nearby, hot temperatures may have minimal effect,” he explains, “but if they’re in a more arid area where the grass doesn’t carry as much moisture content and they don’t have a fairly close water supply, heat can have quite an effect on livestock.”
In addition to providing water content, Logan notes lush grasses can also contribute to ground temperature and shade.
“Taller grass seems to create a cooler surface than pastures with shorter grass,” he comments.
According to Logan, producers should consider the possibility of heat stress any time temperatures are sustained above 90 degrees Fahrenheit.
“If the temperature is in the upper 90s or in the 100s, it’s even more of a concern,” says Logan.
Heat impacts on cattle are largely influenced by the availability of shade and water, as well as by other factors including hide color and breed.
“If cattle don’t have access to shade, we see more of an impact,” he continues.
Logan explains there are several warning signs producers should watch for to assess if cattle need intervention.
“If an animal is panting, having difficulty breathing and slobbering, they may need veterinary intervention,” says Logan.
The main priority for producers while waiting for a veterinarian is to get the animal hydrated.
“If producers are able to get the animal to drink, they should allow it. Ranchers can also tube distressed livestock to get cool water into them and decrease the animal’s core temperature,” comments Logan.
Removing the animal from direct sunlight, if possible, is another important strategy to help an animal in crisis.
“Anything ranchers can do to help avoid direct sun rays on stressed animals will be helpful, so provide some kind of shade, even if it’s temporary,” he continues.
Producers can also use a hose or a bucket to apply water directly on the animal’s body to reduce core temperature.
To reduce the impacts of heat on cattle, Logan stresses access to good water sources is critical.
“Livestock water requirements are going to increase, so that’s a really big thing,” says Logan.
When feasible, he also advises providing shady areas to allow cattle to get out of the sun.
Oftentimes, Logan notes other factors can further stress animals in heat stress situations, and management strategies should be used to limit them.
“When there’s heat stress, there are other things that go hand-in-hand with that,” comments Logan. “Number one would be flies and external parasites that can be a problem.”
He continues, “If producers have animals that are showing stress, keeping an insect repellent on them can help reduce that stress.”
Temperature and humidity are two of the primary factors that impact the likelihood of heat stress, says Logan, noting there are resources producers can use to assess the likelihood in their area.
“Producers can find livestock weather hazard guides that give them a good indication of when there might be some actual dangers,” concludes Logan. “These guides show humidity and temperature and tells people when they should be on the lookout for stress conditions.”
Emilee Gibb is editor of Wyoming Livestock Roundup and can be reached at firstname.lastname@example.org.