Supporting Info

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.

windscreens-1

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