Research Notebook Other stories Reducing dietary phosphorous in feedlots makes environmental, economic sense P hosphorous is essential to beef nutrition, but feeder cattle typically get too much of a good thing. The excess doesn't hurt or help cattle but is an unnecessary expense and an environmental concern, said University of Nebraska Animal Scientist Terry Klopfenstein. He and graduate student Galen Erickson studied the effects of reducing dietary phosphorous on feedlot calf and yearling performance and on the amount of phosphorous in manure. We fed about 60 percent less phosphorous than is typically being fed in the industry.
Cattle get plenty of phosphorous in regular rations.
Feeding only enough phosphorous to meet animal needs means less phosphorous in manure. In this study, reducing dietary phosphorous 34 percent for calves and 44 percent for yearlings reduced phosphorous in manure by 38 percent and 59 percent, respectively. The amount of manure applied to land is based on matching its nitrogen content to crop needs. This won't hurt crops but excess phosphorous can wash off fields and pollute surface water by promoting excessive plant and algae growth that disrupts the ecosystem and depletes oxygen for fish. Producers who apply manure to land must keep records of application sites, amount of manure applied and its nutrient content, including nitrogen and phosphorous.