Winter cold and wind are soon going to be upon us. Wind chill values are a usual part of any winter weather forecast. Wind chill also impacts livestock, so developing some type of wind protection is beneficial to the performance and well-being of the animals we care for.
Research has shown that below 30 degrees Fahrenheit, energy requirements of beef cattle increase about 13% for every 10-degree drop in windchill. Providing wind protection is therefore beneficial in reducing the amount of extra feed or supplement needed to overcome the impact of windchill.
Windbreaks or wind protection comes in a variety of forms. If natural windbreaks are unavailable, man-made structures can be constructed. There are a few guidelines to follow, however, in order to make these structures more effective.
Solid windbreaks are not recommended. Wind protection is lessened downwind of the structure compared to windbreaks that provide some porosity. Also, drifting snow due to down drafting is an additional problem close to the structure and can reduce the benefit of the windbreak.
Recommendations for cattle windbreaks suggest a minimum height of 10 feet with 25 to 33 percent porosity. This allows some air movement close to the structure and reduces the amount of snow deposited close to the downwind side of the windbreak. Leeward wind and drift protection is provided 8 to 10 times the height of the structure with this amount of porosity. For example, a 10-foot-tall structure with 25% porosity would provide wind and drift protection approximately 80 to 100 feet downwind of the windbreak.
If constructing a structure with 6-inch-wide lumber, a spacing of 1.5 to 2 inches between boards will provide the recommended amount of porosity. Also be sure to leave some space at the bottom of the windbreak for a bit of air flow and to allow the area to dry out. Four to six inches are recommended. If necessary, some straw or hay could be placed at the bottom of the windbreak during extreme weather events. Provide about 25 square feet of protection per cow or 1 foot of length per cow. A width to height ratio of 10:1 is also recommended, so the length of a 10-foot-tall structure should be 100 feet for maximum wind protection.
Windbreaks should be oriented perpendicular to wind direction, but V-shaped or L-shaped structures can also be effective. Windspeed will increase around the edges of windbreaks, so keep edges away from waterers, feed bunks, and resting areas. Also pay attention to windbreak placement due to the potential for drifting snow.
Wind protection is beneficial to livestock but be sure if constructing windbreaks that you also consider drifting snow so a solution to one problem doesn’t cause another one. Farm site planning, building placement, and potential for vegetative windbreaks are other considerations to keep in mind.
There are a variety of resources available for planning both constructed wind breaks as well as planting, placement, and species selection for vegetative windbreaks. Many different materials can be used for this purpose but keeping in mind a few general guidelines will make wind protection for farmsteads and livestock more effective.
Information for this article is taken from “Windbreak Fences” in the Beef Cattle Handbook available at iowabeefcenter.org and from “Guidelines for Livestock Windbreaks” available from South Dakota State University Extension.
Contact me at schmitze@missouri.edu or by calling the Pettis County Extension Center at 660-827-0591 if you have additional questions.
