Table 1 Critical temperatures for beef cattle are determined in part
by the condition of the coat. Below the critical temperature, livestock
must expend more energy in order to keep warm.
Coat Description
Critical Temperature
Summer Coat or Wet Fall Coat Winter Coat Heavy Winter
Coat
59 Degrees F 45 Degrees F 32 Degrees F 18 Degrees
Adapted
from D.R. Ames, Kansas State University
Kansas cattle producers indicate
that on average, calving success increases by 2 percent if cows are
protected by a windbreak. Canadian researchers found that cattle on
winter range, in unprotected sites, required a 50 percent increase in
feed for normal activities. An additional 20 percent increase was
necessary to overcome the direct effects of exposure to a combination of
cold temperatures and wind. Wind protection reduced these needs by
half.
The amount of feed required to maintain body temperature in
cattle is reduced when they are protected by windbreaks. For example,
and 880-pound animal, with its winder coat, has a critical temperature
of 32 degrees (table 1) and requires 1.1 percent more feed per degree of
cold (table 3) if the temperature is 10 degrees and the wind speed is
10 miles per hour, the wind chill temperature is 9 degrees below zero
(table 2) and the animal needs 45 percent more feed (critical
temperature minus wind chill temperature times increased feed
requirement). If this same animal were protected by a windbreak
providing a 70 percent reduction in wind speed, the wind chill factor
would change from minus 9 degrees to 2 degrees above zero. The degrees
of cold would be 30 and the increase feed requirement would be only 33
percent, a savings of 12 percent. Colder temperatures or higher wind
speeds would result in larger savings due to windbreak protection.
Table 2 Animal wind-chill chart. As temperature decreases and wind
speed increases, the danger to animals becomes greater.
Researchers at Purdue University found that energy
requirements for cows in good condition increased 13 percent for each
degree drop in wind chill temperature below 30 degrees. A similar study
in Iowa on calves and yearlings indicated that requirements for feed
were 7 percent greater for those in open lots than for similar animals
with shelter. Studies in Montana indicated that during mild winters,
beef cattle sheltered by windbreaks gained an average of 34 to 35 pounds
more than cattle in an open feedlot. During severe winters, cattle in
feedlots protected from the wind, maintained 10.6 more pounds than
cattle in unprotected lots.
OTHER USES May also be used for the following items and many more:
Golf courses - keeps sand from blowing out of traps during off season months
Bleacher/Dugout covers - Provides excellent source of shade
Hay Sheds - Helps prevent hay shrinkage
Feedlots - Provide shade and protection from damaging wind