By Donald Stotts
It’s been a winter that no matter where you are, you’d probably like to forget. Some parts of the country are warm and very, very dry. Good for calving, but not a promising start for spring and summer grazing.
Other parts of the country have been cold and wet. And with calving season underway for many, it’s worth reviewing re-warming methods for cold-stress calves, says Glenn Selk, Oklahoma State University Cooperative Extension emeritus animal scientist.
Selk warns that newborn calves that are not found for several hours after birth and have been exposed to exceedingly cold temperatures may become hypothermic or at least extremely stressed. “A review of the scientific data on using a warm water bath to revive cold-stressed newborn calves bears repeating,” he said.
In a Canadian study, animal scientists compared methods of reviving hypothermic or cold-stressed baby calves. Heat production and rectal temperature were measured in 19 newborn calves during hypothermia and recovery when four different means of assistance were provided.
Hypothermia of 86 degrees F rectal temperature was induced by immersion in cold water. Calves were re-warmed in an air environment of 68 degrees to 77 degrees where thermal assistance was provided by added thermal insulation or by supplemental heat from infrared lamps. Other calves were re-warmed by immersion in 100-degree warm water. The normal rectal temperatures before the induction of cold stress were 103 degrees.
“The time required to regain normal body temperature from a rectal temperature of 86 degrees F was longer for calves with added insulation and those exposed to heat lamps than for the calves in the warm water treatments; 90 and 92 minutes versus 59 minutes, respectively,” Selk says.
During recovery, the baby calves re-warmed with the added insulation and heat lamps had to use up more body heat metabolically than the calves re-warmed in warm water. Total heat production during recovery was nearly twice as great for the calves with added insulation and exposed to the heat lamps than for the calves placed in warm water.
“This type of body heat production leaves calves with less energy to maintain body temperature when returned to a cold environment,” Selk says.
By immersion of hypothermic calves in warm water, the study indicated that normal body temperature was regained most rapidly and with minimal metabolic effort.
“When immersing cold-stressed baby calves, do not forget to support the head above the water to avoid drowning the calf that you are trying to save,” Selk says. “Also make certain that they have been thoroughly dried before being returned to the cold weather and their mothers.”
Stotts is a communication specialist at Oklahoma State University