By Beth Doran
Heat alone is hard enough on cattle. Add humidity and the heat index can become staggering. To help you plan for summer heat events, the USDA Meat Animal Research Center in Clay Center, Neb. has developed a heat stress app for your cell phone. Go to the app store (if you have an iPhone) or Google Play (if you have an Android phone), search for “Heat Stress” and look for the icon shown. Download and use.
Yet, despite planning via the help of this technology, there are times when you will have to implement measures to keep cattle cool. There are two common options - install sprinklers or provide shade. An Iowa Beef Center report suggests the effects of shade and sprinklers for feedlot cattle are not additive. Use either shade or sprinklers, but not both. Shades reduce the solar heat load, but does not affect the air temperature.
There are a number of shades currently on the market varying in design, material and portability. But, important design considerations pertain to each. East-west orientations provide greater ground shadow whereas north-south orientation minimizes mud build-up. Provide approximately 20 to 40 square feet of floor space per animal (depending on the size of the animal) and avoid overcrowding. Optimal shade height ranges from 7 to 14 feet, with higher shade heights increasing air movement under the shade and providing for easier manure removal.
Various types of materials have been used for roofing. Solid, reflective roof materials (white-painted galvanized or aluminum) are most effective in reducing heat load. Slats, plastic and other shade materials with less than total shading capability can be effective if they provide 60% shading, and they handle wind better than solid cover shades.
Some designs for shades are really creative. The picture above shows a shade with a dual purpose. In the summer, it provides shade from solar radiation. When it's folded down in the winter, it serves as a windbreak. Pretty cool (at least in the summer)!
Beth Doran is an Iowa State University Extension beef specialist