Editor's Note: This Tip of the Week has been brought to you by the Dairy Calf & Heifer Association.

According to the National Animal Health Monitoring System (NAHMS) findings in 2007, the average mortality of pre-weaned calves on farms during 2006 was 7.8%. Pre-weaned death may result from respiratory infections or diarrhea. These infections may initiate from dystocia and even poor environmental conditions at birth. 

During the colder seasons, dystocia (difficult births) and hypothermia (cold stress) are the primary reasons for death in calves.

Types of hypothermia:

  1. Exposure (gradual) Hypothermia:
    This form of hypothermia consists of a steady loss of body heat in a cold environment through respiration, evaporation and lack of suitable hair coat, body flesh or weather protection.
  2. Immersion (acute) Hypothermia:
    This form of hypothermia is most common after birth and occurs when there is a rapid loss of body heat due to a wet, saturated coat in a cold environment. Added causes for acute hypothermia may include being born in snowy conditions or on wet ground and if a calf is drenched from heavy rain in cold environments.

Levels of hypothermia:

  • Mild hypothermia occurs when the core temperature falls below normal, which is approximately 101.5 degrees Fahrenheit for dairy calves.
  • Severe hypothermia occurs when temperatures fall below 64 degrees Fahrenheit.
    • At this point, their vital organs begin to get cold and signs of life may be difficult to detect.

Detecting and dealing with hypothermia:

  • Calves may not always appear to be hypothermic; therefore, taking the body calf's temperature will assist in determining the level or degree of hypothermia.
  • Return calf's core temperature to normal. Use dry towels and calf blankets to dry off the calf.
  • Feeding the hypothermic calf warm colostrum as soon as possible aids in speeding up the recovery, while warming the calf from the inside out.
  • Return calf to its normal setting after it is fully dried off and has regained normal body temperature.

Source: Hypothermia & Newborn Calves, by Tracey Renelt