How cold stress affects newborn calves | TSLN.com

How cold stress affects newborn calves

Photo by Heather Smith Thomas

Calves that are chilled at birth, without immediate assistance to warm/dry them and make sure they ingest colostrum in a timely manner, have poor survival rates. If a calf’s mouth gets cold before he suckles, he may not be able to get the teat in his mouth and suck, and therefore does not obtain crucial energy (for keeping warm) and the antibodies he needs – to protect him against disease. Also, his ability to absorb the antibodies from colostrum diminishes as he becomes colder.

As stated by Dr. Robert Callan, Colorado State University, calves born in cold weather may suffer adverse effects if they don’t get right up and nurse before they chill.

“The first thing to understand about body temperature in newborn calves is that they start out with a high temperature, about 103 degrees F,” says Callan. “After they’re born it starts to drop and is down to 101.5 or 102 within a few hours (which is normal temperature for cattle). But if weather is cold and it drops below 100, this means the calf is not able to thermo-regulate and keep himself warm.

“A normal, healthy calf has a tremendous ability to thermo-regulate, especially if the cow licks him off quickly and helps dry him.”

A wet calf will continue to chill if weather is cold and windy, due to rapid evaporation of moisture and subsequent heat loss.

“High risk calves also chill quickly,” he says. “These include calves that suffer prolonged birth, twins, calves born to sick or thin cows. Cows deficient in energy and protein may give birth to weak calves that don’t have much reserve, and their colostrum will have less energy and fewer antibodies. If the calf doesn’t nurse soon, he’ll start depleting his blood glucose within about 30 to 60 minutes. The body tries to replenish this from liver glycogen stores but these can be used up within four to six hours and the calf then becomes hypoglycemic. If he fails to receive proper nutrition, he’ll deplete his brown fat reserves in one to six days and starve.”

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Calves born to undernourished cows have less reserve than cows born to well nourished cows. In cold weather a newborn calve requires extra energy to keep warm, above the normal maintenance requirements.

“The general consensus is that the cold calf does not have energy for the cellular functions to work properly,” says Dr. James England, University of Idaho, Caine Center. “A cold calf has used up all his brown fat, and what little bit of protein was left in the stomach (in the amniotic fluid), trying to keep warm. There isn’t enough energy for the cellular functions to work in transporting things back and forth in and out of the cells. The motility of the GI tract is also impaired. There is also a direct correlation between suckle reflex and uptake of antibodies. Studies have shown that suckling makes the calf several times more able to absorb the globulins than if you give the colostrum via tube, bypassing the suckle.”

If you can get the calf to nurse the cow or suck a bottle of warm colostrum, this is best, but if he’s too cold to suck, the next best thing is to give colostrum via tube.

“In that situation you are trying to warm him up and get some energy into him so he can start generating his own body heat,” says England. “The problem with a chilled calf is that he’s used up all his energy and has nothing left to operate on. The cellular functions are not working to transport fluids across membranes or move the intestines. Everything is shutting down. You have to get some energy into him, and even though colostrum is the best, regular milk is better than nothing.”

The calf will benefit from the nutrition and also the warmth. Warm milk can help warm him internally.

“The ideal situation is fresh warm colostrum from the dam, because this contains viable immune cells that help populate the immune system,” he says. “The big drawback to using frozen colostrum (that you’ve thawed and warmed) is that it is devoid of these living cells. The white cells obtained directly from the mother help establish the newborn calf’s immune system.”

Colostrum has a much higher protein level and more digestible protein and fat than regular milk, and the proteins handle freezing quite well, but the white cells in fresh colostrum are more functional.

“Some people also feel that these cells go into the lymph nodes of the calf and establish a population, but the general consensus is that these are functioning cells that can produce antibodies, eat up bacteria, and give additional protection beyond just the antibodies present in the colostrum,” says England.

Some of these stay in the gut awhile, rather than being absorbed through the intestinal lining, and while in the gut can neutralize ingested pathogens and protect the calf from scours and other diseases early in life. “The key is to get colostrum into the calf as early as possible, to give the calf a jump-start,” he says.

In years past, some herds had problems with what was loosely termed “weak calf syndrome” and a number of studies were done. Calf survivability was poor, especially in cold weather.

“A lot of the problem was nutritional, and some of it was due to selenium deficiencies or protein deficiencies,” says England. “For a long time we were looking for an infectious cause, and for a while we tried to blame it on BVD, but that didn’t pan out as the cause. A lot of what we described as weak calf syndrome was actually trace mineral based, particularly selenium. When ranchers started supplementing the cows and providing adequate protein and trace minerals, these problems diminished.”

Calves that are chilled at birth, without immediate assistance to warm/dry them and make sure they ingest colostrum in a timely manner, have poor survival rates. If a calf’s mouth gets cold before he suckles, he may not be able to get the teat in his mouth and suck, and therefore does not obtain crucial energy (for keeping warm) and the antibodies he needs – to protect him against disease. Also, his ability to absorb the antibodies from colostrum diminishes as he becomes colder.

As stated by Dr. Robert Callan, Colorado State University, calves born in cold weather may suffer adverse effects if they don’t get right up and nurse before they chill.

“The first thing to understand about body temperature in newborn calves is that they start out with a high temperature, about 103 degrees F,” says Callan. “After they’re born it starts to drop and is down to 101.5 or 102 within a few hours (which is normal temperature for cattle). But if weather is cold and it drops below 100, this means the calf is not able to thermo-regulate and keep himself warm.

“A normal, healthy calf has a tremendous ability to thermo-regulate, especially if the cow licks him off quickly and helps dry him.”

A wet calf will continue to chill if weather is cold and windy, due to rapid evaporation of moisture and subsequent heat loss.

“High risk calves also chill quickly,” he says. “These include calves that suffer prolonged birth, twins, calves born to sick or thin cows. Cows deficient in energy and protein may give birth to weak calves that don’t have much reserve, and their colostrum will have less energy and fewer antibodies. If the calf doesn’t nurse soon, he’ll start depleting his blood glucose within about 30 to 60 minutes. The body tries to replenish this from liver glycogen stores but these can be used up within four to six hours and the calf then becomes hypoglycemic. If he fails to receive proper nutrition, he’ll deplete his brown fat reserves in one to six days and starve.”

Calves born to undernourished cows have less reserve than cows born to well nourished cows. In cold weather a newborn calve requires extra energy to keep warm, above the normal maintenance requirements.

“The general consensus is that the cold calf does not have energy for the cellular functions to work properly,” says Dr. James England, University of Idaho, Caine Center. “A cold calf has used up all his brown fat, and what little bit of protein was left in the stomach (in the amniotic fluid), trying to keep warm. There isn’t enough energy for the cellular functions to work in transporting things back and forth in and out of the cells. The motility of the GI tract is also impaired. There is also a direct correlation between suckle reflex and uptake of antibodies. Studies have shown that suckling makes the calf several times more able to absorb the globulins than if you give the colostrum via tube, bypassing the suckle.”

If you can get the calf to nurse the cow or suck a bottle of warm colostrum, this is best, but if he’s too cold to suck, the next best thing is to give colostrum via tube.

“In that situation you are trying to warm him up and get some energy into him so he can start generating his own body heat,” says England. “The problem with a chilled calf is that he’s used up all his energy and has nothing left to operate on. The cellular functions are not working to transport fluids across membranes or move the intestines. Everything is shutting down. You have to get some energy into him, and even though colostrum is the best, regular milk is better than nothing.”

The calf will benefit from the nutrition and also the warmth. Warm milk can help warm him internally.

“The ideal situation is fresh warm colostrum from the dam, because this contains viable immune cells that help populate the immune system,” he says. “The big drawback to using frozen colostrum (that you’ve thawed and warmed) is that it is devoid of these living cells. The white cells obtained directly from the mother help establish the newborn calf’s immune system.”

Colostrum has a much higher protein level and more digestible protein and fat than regular milk, and the proteins handle freezing quite well, but the white cells in fresh colostrum are more functional.

“Some people also feel that these cells go into the lymph nodes of the calf and establish a population, but the general consensus is that these are functioning cells that can produce antibodies, eat up bacteria, and give additional protection beyond just the antibodies present in the colostrum,” says England.

Some of these stay in the gut awhile, rather than being absorbed through the intestinal lining, and while in the gut can neutralize ingested pathogens and protect the calf from scours and other diseases early in life. “The key is to get colostrum into the calf as early as possible, to give the calf a jump-start,” he says.

In years past, some herds had problems with what was loosely termed “weak calf syndrome” and a number of studies were done. Calf survivability was poor, especially in cold weather.

“A lot of the problem was nutritional, and some of it was due to selenium deficiencies or protein deficiencies,” says England. “For a long time we were looking for an infectious cause, and for a while we tried to blame it on BVD, but that didn’t pan out as the cause. A lot of what we described as weak calf syndrome was actually trace mineral based, particularly selenium. When ranchers started supplementing the cows and providing adequate protein and trace minerals, these problems diminished.”