Take precautions when warming cold or frozen calves
March 15, 2019
Calves born during blizzards or cold weather become immediately chilled, and older calves may also suffer frostbite if they don't have shelter. Any calf with body temperature below 100 degrees F. needs warming. There are several ways to safely warm calves, and the methods you choose may depend on your facilities.
Dr. Robert Callan at Colorado State University said a newborn calf needs colostrum immediately, to provide energy so he can produce his own body heat. Feed at least a quart. If he's too cold to suck, give it by tube. A cold calf only has about two hours' worth of stored energy in terms of brown fat, and what was left in the stomach from the amniotic fluid. When those stores are used up, he can't keep warm enough to sustain life in cold weather. Colostrum is the best thing to feed him because it's easy to digest and contains twice the fat energy of regular milk.
You must also warm the calf externally. Some people use a warm water bath because it warms the calf's extremities and body surface quickly, but this is hard to do out in a pasture. Using warm water is also labor intensive because you then have to get the calf completely dry afterward.
"What I like best, since it's easier, is use a warming box," Callan said. "You need electricity, but a small ceramic electric heater in a small enclosed crate — where you can regulate the temperature — works well. You are not only warming the cold body surface, but the calf is breathing warm air into the lungs, which helps raise his core temperature. All his blood is going through his lungs, so if he can breathe warm air this really helps. A warming crate can be very beneficial for hypothermic calves," he said.
In some cases your first option might be to put a cold calf on the floor of your pickup with the heater running — if you find him a long ways from the barn or electricity source. If his feet are cold, he is chilled, and you must get him warm.
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Callan recommends rechecking the calf's temperature every few hours to make sure it is rising. "The energy provided with one feeding of colostrum or milk can be used up in four to six hours and the calf may need some more," Callan said.
The main thing is get the calf out of the snow (onto some straw or something dry where the cow can lick him dry and take care of him), and dried if he's chilled already. If you can get the calf indoors in a warm place, you can use warm water to help thaw cold, freezing extremities (feet, ears, tail), but if he's still outdoors it's counterproductive to use hot water. You're losing ground if you keep the calf wet, because the moisture cools so fast. You have to get him dry. Hot water bottles wrapped in towels, or electric blankets, can also help a calf that's just chilled and not frozen.
Some years the weather may be so cold (or the calf is born during a blizzard) that even a well-mothered calf may freeze if he's born outdoors with no shelter. Your only hope for saving the calf is finding him in time to warm him. Ears and tails may be frozen and eventually slough off, but you can save the calf if you can get his core body temperature back up to normal.
A safe way to warm a severely cold calf is with warm IV fluids and warm air (to warm the air he's breathing). You need to warm the innermost part of the body as swiftly as you warm the outside. If the calf is wet, you need to be drying him at the same time. Towels and hair driers can help speed the process.
If the calf was merely chilled and gets his body temperature back up to normal within an hour or so, and he has a belly full of colostrum or milk (regular milk works fine for an older calf that's not newborn) and is now dry, he can probably go back out with mom. If he suffered frostbitten ears, tail or feet, however, and those extremities are compromised, he needs to stay indoors (perhaps with mom in a stall in the barn, with good bedding) until he is recovered and the frostbitten tissues are no longer swollen and painful. Otherwise they are more vulnerable to cold stress and freezing again.
If body tissues become too cold, ice crystals form inside cell membranes and the cells rupture, killing the tissues. If it's just the superficial skin layers, they become discolored then slough away (like a superficial burn peeling off). Damage to deeper layers and to small blood vessels near the surface may lead to more extensive tissue death. If legs, tail and ears are completely frozen, the calf may eventually lose his ears, or tail, or even his feet. Pricking the frozen extremity with a pin or needle (to see if there is any blood supply or any sensation/feeling in the tissues) can be a clue as to whether the tissue has a chance to return to proper function.
If the skin is actually frozen, don't rub the cold extremities too vigorously (in an attempt to stimulate better circulation) since this may further injure the damaged skin. If the tissue has not completely died, the frozen area may become swollen as blood returns to the area, due to direct injury to the blood vessels and impairment of fluid movement in and out of the tissues.
Precautions for warming in hot water: The quickest way to thaw a frozen calf is with warm water, but if you use this method make sure the water is not too hot. If it's very much above normal body temperature, it may damage the skin — which is already compromised if it's frostbitten. Rapid thaw at moderate temperature (100 to 105 degrees F) is best. Heat injury is always a risk if water is above 115 degrees. Monitor rectal temperature to make sure you don't overheat the calf. There have been reports of extremely cold calves going into shock and dying when put into hot water. The sudden change may stop the heart.
In a cold animal, blood has been shunted away from the extremities and into the body core, to try to keep internal organs warm enough to keep functioning. If you suddenly put the cold calf into hot water this may drive cold from the outer body surfaces into the body core. If the heart is chilled too much (cold shock), it will stop, and the calf will suddenly die. It's better to start with lukewarm water and gradually warm it to body temperature (101 degrees for a calf). Remember that humans who suffer hypothermia or whose temperature is drastically lowered for surgery are brought back to normal temperature slowly.
If you warm the calf in a tub, completely dry him before he goes back outside to cold temperatures. If he's wet, he may chill again. Make sure you don't wash all the amniotic fluid off a newborn calf. If he's perfectly clean and dry when you take him back to mama she may not recognize his smell and refuse to believe that it's her calf. ❖
— Smith Thomas is a cattle rancher, horseman, freelance writer and book author, ranching with her husband near Salmon, Idaho. She can be reached at email@example.com.