Windbreaks offer critical protection from Western winters
Over the past few weeks, frigid temperatures and howling winds have proved only the toughest can survive a nasty Wyoming winter. Since livestock performance and survival is heavily affected by temperature and wind, one can only imagine how hard of a toll recent conditions have had on cattle across the West.
In a University of Lincoln-Nebraska (UNL) BeefWatch newsletter titled “Windbreaks for Protection and Snow Diversion,” published on Jan. 1, UNL Extension Educator Brad Schick notes windbreaks are an important tool for keeping cattle out of the wind.
“Shelter for livestock during winter months can influence the success of calving on a livestock operation. In fact, calving success can increase by two percent behind a windbreak,” states Schick. “Additionally, in Montana feedlots during severe winters, cattle behind windbreaks gained 10.6 pounds more than cattle without windbreaks.”
Constructing a windbreak
Since protection from the wind and snow isn’t always readily available from natural topography or living windbreaks such as trees or shrubs, Schick notes it is important to construct windbreaks to increase livestock protection.
He believes it is critical to keep the end goal in mind when installing a windbreak.
“A windbreak will only be as good as it is designed, and using the wrong design can cause more harm than good,” he explains. “Knowing the purpose of the windbreak is vital to its success.”
According to Schick, there are several different options available to producers when constructing a windbreak, including permanent, porous and non-porous structures.
Schick points out research by the U.S. Forest Service, conducted at the Rocky Mountain Research Station, examined non-porous, solid windbreaks, while research by the University of Saskatchewan, Saskatchewan Department of Agriculture and Food and Manitoba Agriculture looked at the benefits of porous windbreaks.
“Ultimately, the turbulence of the wind behind the windbreak determines the size of the protected area and the degree and placement of snow accumulation,” he says.
Solid windbreaks
According to Schick, a solid windbreak constructed in the shape of a “V” will create adequate protection from the wind, while minimizing snow accumulation.
“The sides of the ‘V’ should form a 90-degree angle, and the point should be built facing into the prevailing winter winds. This will cause snow to be diverted around the ends of the barrier and form drifts away from the sheltered area,” he explains.
With this design, Schick says shelter will be downwind about five times the height of the windbreak, and will reduce wind speed by 60 percent with minimal snow accumulation.
“The shelter width, measured as the distance between the open ends of the windbreak’s sides, should not exceed 15 times the height of the barrier. For example, an eight-feet tall barrier can have sides no longer than 85 feet because the distance between the ends of the sides with that configuration is 120-feet wide,” he says. “If the sides are longer, snow will begin to drift over the barrier and into the sheltered area.”
For producers who may not have the materials or funds to build a permanent “V”-shaped structure, Schick notes the same design can be accomplished by stacking round bales or placing tarps over two eight-feet long panels.
Porous windbreaks
When building a porous windbreak – permanent or temporary – Schick encourages producers to construct them in a line. He notes the effectiveness of a porous windbreak is determined by the open area as a percentage of the total area, which affects the amount of wind reduction.
“Porosity at 25 to 33 percent will optimize protection from wind and snowdrifts. Years of research have determined the protected area to be eight to 10 times the height of the windbreak. Therefore, a 10-foot tall fence – with 25 to 33 percent porosity – will provide 80 to 100 feet of protection behind it,” he says.
When using vertical boards to build a windbreak, Schick advises producers to use six-inch boards with two-inch spacings to create 25 percent porosity and to ensure the base of the windbreak is as wide as it is tall when constructing a temporary structure, to keep it from falling over.
Producers looking for portable, sturdy and low-cost options may consider using axles and hitches or a steel frame and vertical boards when constructing their windbreak.
Temporary windbreaks
Like permanent structures, Schick explains there are several advantages and disadvantages to using temporary or portable windbreaks.
Advantages include the ability to move structures to calving pastures, reducing hay loss fed in bunks or on the ground, offering shelter for cattle grazing crop residue fields, concentrating manure in a nutrient poor portion of the field and avoiding feed residue buildup.
On the other hand, Schick says disadvantages may include the act of moving windbreaks, toppling in extreme winds, a higher associated cost and the potential for the base to freeze to the ground.
Hannah Bugas is the managing editor of the Wyoming Livestock Roundup. Send comments on this article to roundup@wylr.net.
