Managing Phosphorous in Cattle Diets with Distillers Grains

Dan Loy, Wendy Powers, John Lawrence, Allen Trenkle, and Garland Dahlke (Faculty Animal Science and Economics Departments)


The ethanol industry continues to rapidly expand in Iowa.  Along with leading the nation in ethanol production Iowa also leads in the production of distillers grains and solubles.  As cattle producers increase the feeding levels of these economical feeds, the phosphorous levels of the rations as well as the manure increases.  The Iowa Renewable Fuels Association, Iowa State University Extension, the Iowa Cattlemans Association, the Iowa Department of Natural Resources and USDAs Natural Resources Conservation Service all have interest in improving producer awareness and the development of tools and information to better manage phosphorous in beef operations.


Develop a dialog among the ethanol production industry, the cattle production industry, along with environmental protection agencies on the issue of phosphorous and distillers grains in beef diets.

Develop tools and information to aid producers and technical service providers to better manage phosphorous in beef operations.

Develop an awareness of the issue and its management among technical service providers across Iowa.


Coordinated by the Iowa Renewable Fuels Association, representatives of Iowa State University, the Iowa Cattlemans Association, the Natural Resource Conservation Service and the Iowa Department of Natural Resources met five times over the past year to discuss the issue of phosphorous management in beef cattle fed distillers grains.  As a direct result of that dialog and extension publication, Distillers Grains in Feedlot Diets:  Impact on Phosphorous Excretion (IBC-29) was developed.  Also a survey of Iowa Renewable Fuels Association member ethanol plants was conducted the summarized phosphorous content as well as the content of other nutrients from the various distillers grains and solubles.  A computer program was developed to estimate phosphorous excretion from ration and manure management ( ).  Finally a series of three workshops were conducted educate feed and crop technical service providers on proper phosphorous management in feed and manure for Iowa beef operations.


A working relationship was established among the groups and agencies that can have a positive impact phosphorous excretion in cattle feedlots.  Tools were developed and approximately 50 technical service providers were educated on the issue and tools available for its management. 

September 2006

107 - Iowa Beef Center

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