Manipulation of Animal Diets to Affect Manure Production

The Livestock and Poultry Environmental Learning Center , a National Facilitation Project of the CSREES National Integrated Water Quality Program, and The National Center for Manure & Animal Waste Management , funded by the USDA Fund for Rural America, are important projects helping USDA address this issue.

The amount and composition of neoteric manure can vary considerably and is primarily influenced by the original constitution of the diet. USDA CSREES sponsors research to assess diet manipulation to reduce nutrient excretion from livestock and poultry in order to protect and improve water quality.

Example:

cattle feeding

A new research project at Louisiana State University is looking to determine the effects of poultry diet modifications using phytase to reduce excreted phosphorus and ultimately reduce the amount of phosphorus moving into ground and surface waters.
Using DGS (distillers grains with solubles, a byproduct of ethanol production) in swine and poultry diets will increase N content of both the diet and excreted manure. Intervention with the use of synthetic amino acids can moderate the increase. The concentration of dietary and excreted P will decline when low levels are used, but will increase at higher inclusion levels.
How much can diet modification do to reduce manure phosphorus surpluses? Researchers at Virginia Tech have been studying that question in response to environmental concerns over P losses from animal agriculture to surface waters. They found diet modification decreased the percentage of states with a manure P surplus by 20% and decreased the percentage of counties with the greatest surpluses of manure P by two thirds.

For more information on the current state of knowledge on the manipulation of animal diets, refer to the Manipulation of Animal Diets to Affect Manure Production, Composition and Odors White Paper Summary produced by the National Center for Manure and Animal Waste Management funded through a USDA CSREES Fund for Rural America Grant.

The intent of this page is not to catalogue all activities but rather to indicate the types of research activities in the Animal Waste Management theme across the U.S.