Avoid heat stress when moving or working cattle | TSLN.com

Avoid heat stress when moving or working cattle

Photo by Heather Smith ThomasIf range cattle are being moved in rugged terrain during hot weather, or on a long cattle drive with uphill climbs, it's important to slow the herd down and stop often.

Hot weather can be very hard on cattle, especially when humidity is high (which makes it more difficult for the animal to dissipate body heat), or when cattle exert and overheat. Moving or working cattle in hot weather can become life-threatening if the stockman doesn’t pay attention to signs of heat stress. The fattest animals and those with the most muscle mass or thick hair coat are usually the most at risk because they overheat more readily than a lean or thinly haired animal with less body insulation. Dark colored animals also suffer more readily from heat stress than lighter colored animals.

Dr. Don Spiers, University of Missouri, said the comfort zone of cattle has an upper limit of about 75 degrees, but this can vary depending on how large the animal is, and its color.

“If an animal is dark skinned, chances of heat stress are greater. Studies have shown that about 70 percent of feedlot deaths due to intense heat is in animals with dark hide. Researchers found that animals with black hide get higher body temperature, up to 104 degrees during hot weather – as opposed to light-colored cattle that are usually 101 to 102 degrees, which is normal,” explained Spiers.

Cattle with lots of muscle mass also generate more body heat than cattle with less muscle, because bulky muscles also have more heat to get rid of. “If body temperature climbs to 107 degrees, cattle may suffer heart failure,” he said.

Dr. Tom Welsh, Texas A&M, advises against working animals in the middle of the day during hot weather. “It’s safer to do as much of the work as possible in the early morning or late evening when it’s cooler. Try to avoid bunching up the cattle (which hinders air movement). Give them rest periods periodically, if it’s hot,” he said. If you are working in a corral, there’s limited air movement in solid panel corral chutes. These chutes and alleys can get pretty hot, as well as being physically and psychologically stressful to the animals, which raises their temperatures.

“If you are working cattle, the activity and jostling – especially if they are not experienced and don’t know what is expected of them when moving through the facility – will elevate their body temperature anywhere from 0.5 to 3.5 degrees, just from the stress and exertion,” Welsh said. Anything you can do to minimize stress will help keep them from overheating so much.

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For example, move cattle in smaller groups, give them less standing time when confined in the long alleyway or chute. “We try to work cattle in very small groups if we have enough extra holding pens and enough people,” explained Welsh.

If moving cattle on a hot day, take it slow. The best thing is to allow cattle to choose their own pace and graze a little as they go. One problem with taking cattle from one pasture to a new one is that often cows eagerly travel at a speed too fast for their calves, and calves end up overheated before they get there. The fat young calves may be breathing with their mouths open, falling behind, or trying to lie down.

If the herd is not slowed down, or made to stop and rest at the first signs of heat stress, calves and fat yearlings may become overheated to the point of dying. If range cattle are being moved in rugged terrain and are not allowed to rest when they start to get tired or overheated, the risks are increased. This is especially true if it’s a long cattle drive with uphill climbs.

Hot weather can be very hard on cattle, especially when humidity is high (which makes it more difficult for the animal to dissipate body heat), or when cattle exert and overheat. Moving or working cattle in hot weather can become life-threatening if the stockman doesn’t pay attention to signs of heat stress. The fattest animals and those with the most muscle mass or thick hair coat are usually the most at risk because they overheat more readily than a lean or thinly haired animal with less body insulation. Dark colored animals also suffer more readily from heat stress than lighter colored animals.

Dr. Don Spiers, University of Missouri, said the comfort zone of cattle has an upper limit of about 75 degrees, but this can vary depending on how large the animal is, and its color.

“If an animal is dark skinned, chances of heat stress are greater. Studies have shown that about 70 percent of feedlot deaths due to intense heat is in animals with dark hide. Researchers found that animals with black hide get higher body temperature, up to 104 degrees during hot weather – as opposed to light-colored cattle that are usually 101 to 102 degrees, which is normal,” explained Spiers.

Cattle with lots of muscle mass also generate more body heat than cattle with less muscle, because bulky muscles also have more heat to get rid of. “If body temperature climbs to 107 degrees, cattle may suffer heart failure,” he said.

Dr. Tom Welsh, Texas A&M, advises against working animals in the middle of the day during hot weather. “It’s safer to do as much of the work as possible in the early morning or late evening when it’s cooler. Try to avoid bunching up the cattle (which hinders air movement). Give them rest periods periodically, if it’s hot,” he said. If you are working in a corral, there’s limited air movement in solid panel corral chutes. These chutes and alleys can get pretty hot, as well as being physically and psychologically stressful to the animals, which raises their temperatures.

“If you are working cattle, the activity and jostling – especially if they are not experienced and don’t know what is expected of them when moving through the facility – will elevate their body temperature anywhere from 0.5 to 3.5 degrees, just from the stress and exertion,” Welsh said. Anything you can do to minimize stress will help keep them from overheating so much.

For example, move cattle in smaller groups, give them less standing time when confined in the long alleyway or chute. “We try to work cattle in very small groups if we have enough extra holding pens and enough people,” explained Welsh.

If moving cattle on a hot day, take it slow. The best thing is to allow cattle to choose their own pace and graze a little as they go. One problem with taking cattle from one pasture to a new one is that often cows eagerly travel at a speed too fast for their calves, and calves end up overheated before they get there. The fat young calves may be breathing with their mouths open, falling behind, or trying to lie down.

If the herd is not slowed down, or made to stop and rest at the first signs of heat stress, calves and fat yearlings may become overheated to the point of dying. If range cattle are being moved in rugged terrain and are not allowed to rest when they start to get tired or overheated, the risks are increased. This is especially true if it’s a long cattle drive with uphill climbs.

Hot weather can be very hard on cattle, especially when humidity is high (which makes it more difficult for the animal to dissipate body heat), or when cattle exert and overheat. Moving or working cattle in hot weather can become life-threatening if the stockman doesn’t pay attention to signs of heat stress. The fattest animals and those with the most muscle mass or thick hair coat are usually the most at risk because they overheat more readily than a lean or thinly haired animal with less body insulation. Dark colored animals also suffer more readily from heat stress than lighter colored animals.

Dr. Don Spiers, University of Missouri, said the comfort zone of cattle has an upper limit of about 75 degrees, but this can vary depending on how large the animal is, and its color.

“If an animal is dark skinned, chances of heat stress are greater. Studies have shown that about 70 percent of feedlot deaths due to intense heat is in animals with dark hide. Researchers found that animals with black hide get higher body temperature, up to 104 degrees during hot weather – as opposed to light-colored cattle that are usually 101 to 102 degrees, which is normal,” explained Spiers.

Cattle with lots of muscle mass also generate more body heat than cattle with less muscle, because bulky muscles also have more heat to get rid of. “If body temperature climbs to 107 degrees, cattle may suffer heart failure,” he said.

Dr. Tom Welsh, Texas A&M, advises against working animals in the middle of the day during hot weather. “It’s safer to do as much of the work as possible in the early morning or late evening when it’s cooler. Try to avoid bunching up the cattle (which hinders air movement). Give them rest periods periodically, if it’s hot,” he said. If you are working in a corral, there’s limited air movement in solid panel corral chutes. These chutes and alleys can get pretty hot, as well as being physically and psychologically stressful to the animals, which raises their temperatures.

“If you are working cattle, the activity and jostling – especially if they are not experienced and don’t know what is expected of them when moving through the facility – will elevate their body temperature anywhere from 0.5 to 3.5 degrees, just from the stress and exertion,” Welsh said. Anything you can do to minimize stress will help keep them from overheating so much.

For example, move cattle in smaller groups, give them less standing time when confined in the long alleyway or chute. “We try to work cattle in very small groups if we have enough extra holding pens and enough people,” explained Welsh.

If moving cattle on a hot day, take it slow. The best thing is to allow cattle to choose their own pace and graze a little as they go. One problem with taking cattle from one pasture to a new one is that often cows eagerly travel at a speed too fast for their calves, and calves end up overheated before they get there. The fat young calves may be breathing with their mouths open, falling behind, or trying to lie down.

If the herd is not slowed down, or made to stop and rest at the first signs of heat stress, calves and fat yearlings may become overheated to the point of dying. If range cattle are being moved in rugged terrain and are not allowed to rest when they start to get tired or overheated, the risks are increased. This is especially true if it’s a long cattle drive with uphill climbs.

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