Reported cattle losses due to heat reached record numbers last summer, but producers do have an option to consider: cattle shades.
According to Jim Krantz, SDSU Extension Cow/Calf Field Specialist, cattle shades may mitigate heat stress for cattle in feedlots and provide economic benefits in terms of continued gains and improved efficiency versus lots with no solar protection.
Indications are that about a 20 degree air temperature difference can be realized through the presence of a shade, and the size of the shade also affects efficiency.
Krantz said that shaded area recommendations per animal vary considerably depending on the source of information.
"One manufacturer of a movable shade in Nebraska suggested 15 square feet per head was adequate while researchers at the University of Nebraska recommend 20-40 square feet per head, recognizing that there is little benefit to overcrowded conditions," Krantz said.
Airflow is also a challenge for some producers.
In 2011 it was discovered that in some cases, winter windbreaks that serve to diminish wind velocity and catch snow from November through March, did not allow sufficient air flow in times of extreme heat and humidity during the summer months resulting in cattle losses.
To ensure sufficient airflow, Krantz says cattle producers need to consider several factors when considering construction of a shade:
*Shades are typically constructed toward the center of a pen to allow cattle access to shade as the shaded area moves across the pen during the day.
*Designs that include a north-south orientation consistently provide dryer pen surfaces as the shadow provided by the shade moves over a greater area.
*Constructing shades over or near waters is not advised.
*It is highly recommended that areas beneath shade structures be regularly cleaned of wet manure to limit odor and ammonia production and maintain a desirable lot surface.
*Increased shade height will allow for greater air movement and cleaning with equipment but is more costly as well. Fourteen foot heights typically allow for both.
"As for the construction materials, Krantz said galvanized or aluminum materials have been utilized in the past as roof materials, but light-colored fabric is becoming the material of choice. It is effective in providing desirable shaded areas and is particularly easier to handle if the roofs are removed or rolled up in the winter.
Consulting with a feedlot engineer is recommended for anyone considering the construction of feedlot shades. When constructed and used properly, they can mitigate the stresses caused by extreme heat and humidity.
To learn more about how to protect your livestock from heat stress visit iGrow.org/Livestock.