Management
Managing Heat Stress
in Beef Herds this Summer
By Kim Mullenix, Extension Animal Scientist, Auburn University
What is heat stress?
Heat stress in the cattle herd may be a concern
during the warmest months of the year in the
Southeast USA (June through early September;
when the temperature is above 85°F and the
humidity is high). Unlike humans, cattle get
rid of excess heat in their system through
breathing and panting more than sweating.
The combination of high temperatures and
high relative humidity can influence animal
performance and decrease production
potential in the cow herd. The combination of
these factors along with animal age, hair coat
color and length, and nutritional status may
influence how animals respond to heat stress.
Potential impacts of heat stress
• Loss in animal performance – body condition
• Less time spent grazing
• Lengthens the estrus cycle
• Weaning and shrink loss among calves
Learning to deal with the heat is a given part of
living in the Southeast. However, the following
provides some preventive measures we can
take to minimize effects on the cattle herd:
Ways to beat the HEAT :
H andle cattle early in the morning
When working cattle in the summer, plan to
handle cattle early in the morning (beginning
at daylight) with the goal of being done around
10 am. While this may be easier said than done,
processing cattle increases the animal’s core
body temperature, and puts them at risk for
experiencing heat stress earlier in the day. This
translates to more time spent in the shade after
working. Work cattle in smaller groups so that
they are not standing in the holding area for more
than 30 to 45 minutes. Use low-stress handling
techniques to minimize stress during handling.
E stablish a grazing management plan
Rotate cattle to new pastures at night rather than
in the morning. While this may seem to counter
the above statement about when to work cattle,
in general, moving cattle to a new pasture is less
stressful to the animal. Moving cattle in the early
evening also coincides with the time of day when
air temperatures are coming down. Cattle often
graze in the early morning or late evening, so
moving to a new pasture area in the early evening
may encourage animals to actively graze as the
daytime temperature begins to decrease. Beef
cattle produce heat during the digestion process
and grazing at night allows them time in the
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