Ask the Expert: Do Calves Sweat?

Posted on November 9, 2012 in Starting Strong - Calf Care
Thanks to Alice Lindborg for submitting this edition’s Ask the Expert question. Alice received a free packet of Secure® 175 because her question was selected. 
Dr. Neil Michael comes to Starting Strong with nearly 30 years of experience as a veterinarian specializing in dairy. He currently works as the director of dairy initiatives for Vita Plus.
Question: In the December edition of Starting Strong, you mentioned we need to make sure calves don’t sweat during the day when blankets are used. The info we operate on is that, physiologically, cattle can’t sweat. Are newborns different? 
Answer: Cattle can be cooled by both evaporative and non-evaporative pathways. Evaporative cooling options include both sweating and respiration.
Cattle do indeed have sweat glands in the skin as do other mammals, but the number and effectiveness of those glands to dissipate heat is less than many other mammals. In dairy cattle (both young and adults), the majority of skin sweat glands are located on the neck and shoulder as compared to the flanks and lower back. Once an animal’s heat load begins to increase, sweat glands are activated to attempt to maintain body temperature.
By design, calf blankets are meant to reduce heat loss of young calves to their surroundings during lower winter temperatures. The problem occurs when daytime temperatures and sunlight increase heat load and thereby activate sweat glands in an attempt to dissipate heat. Alternatively, if sweating proves ineffective, calves may also increase respiration rates to increase evaporative cooling.
In addition to the potential for sweating under calf blankets, condensation may occur under the blanket due to low dew points (the temperature at which air becomes saturated with moisture and dew forms). As a result, both sweating and condensation may result in calves “sweating up” under blankets. That moisture can really chill a calf when the temperature falls at night and predispose them to pneumonia and other health risks. That’s why blankets should be managed properly during periods of high temperature swings and high humidity.

Category: Starting Strong - Calf Care