While calves can tolerate slightly higher temperatures than cows, heat stress typically sets in at air temperatures above 80°F, especially if humidity is also high. To keep themselves cool, calves must utilize energy.

Because they don’t have extra energy stored, they must use energy that normally supports the immune system and growth. This shift in resources can slow growth and leave calves defenseless against any pathogens in their environment.

A calf experiencing mild heat stress is much easier to cool than one that is severely overheated. Check your calves regularly on hot days so you can intervene early when you see telltale signs of heat stress, which include:

  • Reduced movement
  • Elevated body temperature
  • Increased respiration
  • Open-mouthed panting
  • Decreased feed intake
  • Increased water intake